The Hyaluronic Acid Fillers: Current Understanding of the Tissue Device Interface.

PubMed

Greene, Jacqueline J; Sidle, Douglas M

2015-11-01

The article is a detailed update regarding cosmetic injectable fillers, specifically focusing on hyaluronic acid fillers. Hyaluronic acid-injectable fillers are used extensively for soft tissue volumizing and contouring. Many different hyaluronic acid-injectable fillers are available on the market and differ in terms of hyaluronic acid concentration, particle size, cross-linking density, requisite needle size, duration, stiffness, hydration, presence of lidocaine, type of cross-linking technology, and cost. Hyaluronic acid is a natural component of many soft tissues, is identical across species minimizing immunogenicity has been linked to wound healing and skin regeneration, and is currently actively being studied for tissue engineering purposes. The biomechanical and biochemical effects of HA on the local microenvironment of the injected site are key to its success as a soft tissue filler. Knowledge of the tissue-device interface will help guide the facial practitioner and lead to optimal outcomes for patients. Copyright © 2015 Elsevier Inc. All rights reserved.

Compatibilizing Bulk Polymer Blends by Using Organoclays

NASA Astrophysics Data System (ADS)

Si, Mayu; Gersappe, Dilip; Zhang, Wenhua; Ade, Harald; Rafailovich, Miriam; Sokolov, Jonathan; Rudomen, Gregory; Schwartz, Bradley; Fisher, Robert

2004-03-01

We investigated the compatiblizing performance of organoclays on melt mixed binary and tertiary polymer blends, such as, PS/PMMA, PC/SAN, PS/PMMA/PVC and PS/PMMA/PE. These polymer blends were characterized by TEM, STXM, DSC and DMA. TEM and STXM photographs show that the addition of organoclays into polymer blends drastically reduces the average domain size of the component phases. And the organoclay goes to the interfacial region between the different polymers and effectively slows down the domain size increasing during high temperature annealing. DMA and DSC results show the effect of organoclays on the mechanical properties and glass transitions temperature, which indicates the compatibilization on the molecular level. The generalized compatibilization induced by the nanoscale fillers for blends can be explained in terms of mean field models where the reduction of interfacial tension induced by in-situ grafting is counterbalanced by the increased bending energy due to the rigidity of the filler. This in turn can be shown to be a function of the degree of exfoliation, aspect ratio, and polymer filler interactions. Supported by NSF funded MRSEC at Stony Brook

A pseudo-thermodynamic description of dispersion for nanocomposites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jin, Yan; Beaucage, Gregory; Vogtt, Karsten

Dispersion in polymer nanocomposites is determined by the kinetics of mixing and chemical affinity. Compounds like reinforcing filler/elastomer blends display some similarity to colloidal solutions in that the filler particles are close to randomly dispersed through processing. It is attractive to apply a pseudo-thermodynamic approach taking advantage of this analogy between the kinetics of mixing for polymer compounds and thermally driven dispersion for colloids. In order to demonstrate this pseudo-thermodynamic approach, two polybutadienes and one polyisoprene were milled with three carbon blacks and two silicas. These samples were examined using small-angle x-ray scattering as a function of filler concentration tomore » determine a pseudo-second order virial coefficient, A2, which is used as an indicator for compatibility of the filler and polymer. It is found that A2 follows the expected behavior with lower values for smaller primary particles indicating that smaller particles are less compatible and more difficult to mix. The measured values of A2 can be used to specify repulsive interaction potentials for coarse grain DPD simulations of filler/elastomer systems. In addition, new methods to quantify the filler percolation threshold and filler mesh size as a function of filler concentration are obtained. Moreover, the results represent a new approach to understanding and predicting compatibility in polymer nanocomposites based on a pseudo-thermodynamic approach.« less

A pseudo-thermodynamic description of dispersion for nanocomposites

DOE PAGES

Jin, Yan; Beaucage, Gregory; Vogtt, Karsten; ...

2017-09-18

Dispersion in polymer nanocomposites is determined by the kinetics of mixing and chemical affinity. Compounds like reinforcing filler/elastomer blends display some similarity to colloidal solutions in that the filler particles are close to randomly dispersed through processing. It is attractive to apply a pseudo-thermodynamic approach taking advantage of this analogy between the kinetics of mixing for polymer compounds and thermally driven dispersion for colloids. In order to demonstrate this pseudo-thermodynamic approach, two polybutadienes and one polyisoprene were milled with three carbon blacks and two silicas. These samples were examined using small-angle x-ray scattering as a function of filler concentration tomore » determine a pseudo-second order virial coefficient, A2, which is used as an indicator for compatibility of the filler and polymer. It is found that A2 follows the expected behavior with lower values for smaller primary particles indicating that smaller particles are less compatible and more difficult to mix. The measured values of A2 can be used to specify repulsive interaction potentials for coarse grain DPD simulations of filler/elastomer systems. In addition, new methods to quantify the filler percolation threshold and filler mesh size as a function of filler concentration are obtained. Moreover, the results represent a new approach to understanding and predicting compatibility in polymer nanocomposites based on a pseudo-thermodynamic approach.« less

Several braze filler metals for joining an oxide-dispersion-strengthened nickel-chromium-aluminum alloy

NASA Technical Reports Server (NTRS)

Gyorgak, C. A.

1975-01-01

An evaluation was made of five braze filler metals for joining an aluminum-containing oxide dispersion-strengthened (ODS) alloy, TD-NiCrAl. All five braze filler metals evaluated are considered suitable for joining TD-NiCrAl in terms of wettability and flow. Also, the braze alloys appear to be tolerant of slight variations in brazing procedures since joints prepared by three sources using three of the braze filler metals exhibited similar brazing characteristics and essentially equivalent 1100 C stress-rupture properties in a brazed butt-joint configuration. Recommendations are provided for brazing the aluminum-containing ODS alloys.

"Uh," "Um," and Autism: Filler Disfluencies as Pragmatic Markers in Adolescents with Optimal Outcomes from Autism Spectrum Disorder

ERIC Educational Resources Information Center

Irvine, Christina A.; Eigsti, Inge-Marie; Fein, Deborah A.

2016-01-01

Filler disfluencies--"uh" and "um"--are thought to serve distinct discourse functions. We examined fillers in spontaneous speech by youth with autism spectrum disorder (ASD), who struggle with pragmatic language, and by youth with ASD who have achieved an "optimal outcome" (OO), as well as in peers with typical…

Optical coherence tomography for image-guided dermal filler injection and biomechanical evaluation

NASA Astrophysics Data System (ADS)

Singh, Manmohan; Wang, Shang; Yee, Richard W.; Han, Zhaolong; Aglyamov, Salavat R.; Larin, Kirill V.

2017-02-01

Dermal fillers are a very popular anti-ag ing treatment with estimated sales in the billions of dollars and millions of procedures performed. As the aging population continues to grow, these figures are only e xpected to increase. Dermal fillers have various compositions depending on their intended applicati on. Reactions to dermal fillers can be severe, such as ischemic events and filler migration to the eyes. Howe ver, these adverse reactions are rare. Nevertheless, the capability to perform imag e-guided filler injections would minimize th e risk of such reacti ons. In addition, the biomechanical properties of various fillers have been evalua ted, but there has been no investigation on the effects of filler on the biomechanical properties of skin. In this work, we utilize optical cohe rence tomography (OCT) for visualizing dermal filler injections with micrometer-scale sp atial resolution. In addition, we utilize noncontact optical coherence elastography (OCE) to quantify the changes in the biomechan ical properties of pig skin after the dermal filler injections. OCT was successfully able to visualize the dermal filler injecti on process, and OCE showed that the viscoelasticity of the pig skin was increased locally at the filler injection sites. OCT may be able to provide real-time image guidance in 3D, and when combined with functional OCT techniques such as optical microangiography, could be used to avoid blood vessels during the injection.

Characterization Tests for Mineral Fillers Related to Performance of Asphalt Paving Mixtures

DOT National Transportation Integrated Search

1988-01-01

Various studies have shown that the properties of mineral filler, especially the material passing 0.075 mm (No. 200) sieve (generally called P200 material), have a significant effect on the performance of asphalt paving mixtures in terms of permanent...

In vitro aging behavior of dental composites considering the influence of filler content, storage media and incubation time

PubMed Central

Maletz, Reinhard; Ottl, Peter; Warkentin, Mareike

2018-01-01

Objective Over time dental composites age due to mechanical impacts such as chewing and chemical impacts such as saliva enzymes and food ingredients. For this research, the focus was placed on chemical degradation. The objective of this study was to simulate hydrolysis by using different food simulating liquids and to assess their impact on the mechanical parameter Vickers microhardness (MHV) and the physicochemical parameter contact angle (CA). Methods Specimen of three composites (d = 6 mm, h = 2 mm; n = 435) classified with respect to their filler content (wt%), namely low-filled, medium-filled and highly-filled, were stored for 0, 14, 30, 90 and 180 days in artificial saliva (pH 7), citric acid (pH 3; pH 5), lactic acid (pH 3; pH 5) and ethanol (40%vol; 60%vol) and assessed regarding to MHV and CA. Statistics: Kruskal-Wallis test, stepwise linear regression, bivariate Spearman Rank Correlation (p < 0.05). Results While stored in artificial saliva, acid and ethanol the CA decreased especially for the low- and medium-filled composites. It was shown that rising the filler content caused less surface changes in the CA. Storage in ethanol led to a significant decrease of MHV of all composites. Regression analysis showed that the effect of in vitro aging on MHV was mainly influenced by the composite material and therefore by filler content (R2 = 0.67; p < 0.05). In contrast, the CA is more influenced by incubation time and filler content (R2 = 0.2; p < 0.05) leading to a higher risk of plaque accumulation over time. Significance: In vitro aging showed significant changes on the mechanical and physicochemical properties of dental composites which may shorten their long-term functionality. In conclusion, it can be stated, that the type of composite material, especially rising filler content seems to improve the materials’ resistance against the processes of chemical degradation. PMID:29630621

Constitutive Modeling, Nonlinear Behavior, and the Stress-Optic Law

DTIC Science & Technology

2011-01-01

estimates of D̂ from dynamic mechanical measurements. Some results are shown in Figure 58 for a filled EPDM rubber [116]. There is rough agreement with...elastomers and filler-reinforced rubber . 5.1 Linearity and the superposition principle The problem of analyzing viscoelastic mechanical behavior is greatly...deformation such as shear. For crosslinked rubber the strain can be defined in terms of the strain function suggested by the statistical theories of

Effect of carbon nanotube functionalization on mechanical and thermal properties of cross-linked epoxy-carbon nanotube nanocomposites: role of strengthening the interfacial interactions.

PubMed

Khare, Ketan S; Khabaz, Fardin; Khare, Rajesh

2014-05-14

We have used amido-amine functionalized carbon nanotubes (CNTs) that form covalent bonds with cross-linked epoxy matrices to elucidate the role of the matrix-filler interphase in the enhancement of mechanical and thermal properties in these nanocomposites. For the base case of nanocomposites of cross-linked epoxy and pristine single-walled CNTs, our previous work (Khare, K. S.; Khare, R. J. Phys. Chem. B 2013, 117, 7444-7454) has shown that weak matrix-filler interactions cause the interphase region in the nanocomposite to be more compressible. Furthermore, because of the weak matrix-filler interactions, the nanocomposite containing dispersed pristine CNTs has a glass transition temperature (Tg) that is ∼66 K lower than the neat polymer. In this work, we demonstrate that in spite of the presence of stiff CNTs in the nanocomposite, the Young's modulus of the nanocomposite containing dispersed pristine CNTs is virtually unchanged compared to the neat cross-linked epoxy. This observation suggests that the compressibility of the matrix-filler interphase interferes with the ability of the CNTs to reinforce the matrix. Furthermore, when the compressibility of the interphase is reduced by the use of amido-amine functionalized CNTs, the mechanical reinforcement due to the filler is more effective, resulting in a ∼50% increase in the Young's modulus compared to the neat cross-linked epoxy. Correspondingly, the functionalization of the CNTs also led to a recovery in the Tg making it effectively the same as the neat polymer and also resulted in a ∼12% increase in the thermal conductivity of the nanocomposite containing functionalized CNTs compared to that containing pristine CNTs. These results demonstrate that the functionalization of the CNTs facilitates the transfer of both mechanical load and thermal energy across the matrix-filler interface.

The use and correlates of illicit silicone or “fillers” in a population-based sample of transwomen, San Francisco, 2013

PubMed Central

Wilson, Erin; Rapues, Jenna; Jin, Harry; Raymond, H. Fisher

2014-01-01

Introduction There is a dearth of studies to quantify the use of illicit fillers by transwomen. Case studies of illicit filler injections have pointed to an array of serious health complications, including death. Aim The aim of this study was to determine the population prevalence of filler use among transwomen, and to identify correlations with filler use. Methods An analysis of data collected in 2013 with a population-based sample of 234 transwomen recruited using respondent driven sampling (RDS). We used RDS weights to conduct bivariate and multivariate analyses of correlates of filler use. Main Outcome measures Main outcome measures were an RDS-weighted population prevalence of filler use among transwomen and differences in demographic characteristics, transition-related care factors and self-esteem related to appearance. Results Weighted filler prevalence among transwomen was 16.7%. Being a transwomen between 30–49 years of age, owning/renting or living with a partner/family/friend, having had and planning to have surgery in the future and having used non-prescribed hormones were all associated with filler use. HIV was not associated with filler use. Conclusions This study provides the first known estimate to date of the prevalence of filler use in a population-based sample of transwomen in San Francisco. Accessing illicit fillers may be the only choice available for many transwomen due to the cost of legal surgeries and other procedures to change one’s appearance. An important next step in this research is to determine the overall prevalence and long-term consequences of filler use among transwomen, to explore how the use of fillers is protective to the safety and wellbeing of transwomen, and to find safe and affordable alternatives to this method that meets important gender-related appearance needs. PMID:24810672

A case report of ophthalmic artery emboli secondary to Calcium Hydroxylapatite filler injection for nose augmentation- long-term outcome.

PubMed

Cohen, Eyal; Yatziv, Yossi; Leibovitch, Igal; Kesler, Anat; Cnaan, Ran Ben; Klein, Ainat; Goldenberg, Dafna; Habot-Wilner, Zohar

2016-07-08

Filler injection for face augmentation is a common cosmetic procedure in the last decades, in our case report we describe long-term outcomes of a devastating complication of ophthalmic artery emboli following Calcium Hydroxylapatite filler injection to the nose bridge. A healthy 24-year-old women received a Calcium Hydroxylapatite filler injection to her nose bridge for the correction of nose asymmetry 8 years post rhinoplasty. She developed sudden right eye ocular pain and visual disturbances. Visual acuity was 20/20 in both eyes and visual field in the right eye showed inferior arch with fixation sparing and supero-temporal central scotoma. Examination revealed marked periorbital edema and hematoma, ptosis, ocular movements limitation, an infero-temporal branch retinal artery occlusion and multiple choroidal emboli. Eighteen months post initial presentation ptosis and eye movements returned normal and choroidal emboli absorbed almost completely. However, visual acuity declined to 20/60, visual field showed severe progressive deterioration with a central and supero-nasal field remnant and the optic disc became pallor. Cosmetic injection of calcium hydroxylapatite to the nose bridge can result in arterial emboli to the ophthalmic system with optic nerve, retinal and choroidal involvement causing long term severe visual acuity and visual field impairment.

Static and Dynamic Mechanical Characteristics of Ionic Liquid Modified MWCNT-SBR Composites: Theoretical Perspectives for the Nanoscale Reinforcement Mechanism.

PubMed

Abraham, Jiji; Thomas, Jince; Kalarikkal, Nandakumar; George, Soney C; Thomas, Sabu

2018-02-01

Well-dispersed, robust, mechanicaly long-term stable functionalized multiwalled carbon nanotube (f-MWCNT)-styrene butadiene rubber (SBR) nanocomposites were fabricated via a melt mixing route with the assistance of ionic liquid as a dispersing agent. The mechanical properties of f-MWCNT/SBR vulcanizates were compared over a range of loadings, and it was found that the network morphology was highly favorable for mechanical performance with enlarged stiffness. A comparative investigation of composite models found that modified Kelly-Tyson theory gave an excellent fit to tensile strength data of the composites considering the effect of the interphase between polymer and f-MWCNT. Dynamic mechanical analysis highlighted the mechanical reinforcement due to the improved filler-polymer interactions which were the consequence of proper dispersion of the nanotubes in the SBR matrix. Effectiveness of filler, entanglement density, and adhesion factor were evaluated to get an in depth understanding of the reinforcing mechanism of modified MWCNT. The amount of polymer chains immobilized by the filler surface computed from dynamic mechanical analysis further supports a substantial boost up in mechanics. The Cole-Cole plot shows an imperfect semicircular curve representing the heterogeneity of the system and moderately worthy filler polymer bonding. The combined results of structural characterizatrion by Raman spectroscopy, cure characteristics, mechanical properties, and scanning and transmission electron microscopy (SEM, TEM) confirm the role of ionic liquid modified MWCNT as a reinforcing agent in the present system.

Dual-Component Gelatinous Peptide/Reactive Oligomer Formulations as Conduit Material and Luminal Filler for Peripheral Nerve Regeneration

PubMed Central

Kohn-Polster, Caroline; Bhatnagar, Divya; Woloszyn, Derek J.; Richtmyer, Matthew; Starke, Annett; Springwald, Alexandra H.; Franz, Sandra; Schulz-Siegmund, Michaela; Kaplan, Hilton M.; Kohn, Joachim; Hacker, Michael C.

2017-01-01

Toward the next generation of nerve guidance conduits (NGCs), novel biomaterials and functionalization concepts are required to address clinical demands in peripheral nerve regeneration (PNR). As a biological polymer with bioactive motifs, gelatinous peptides are promising building blocks. In combination with an anhydride-containing oligomer, a dual-component hydrogel system (cGEL) was established. First, hollow cGEL tubes were fabricated by a continuous dosing and templating process. Conduits were characterized concerning their mechanical strength, in vitro and in vivo degradation and biocompatibility. Second, cGEL was reformulated as injectable shear thinning filler for established NGCs, here tyrosine-derived polycarbonate-based braided conduits. Thereby, the formulation contained the small molecule LM11A-31. The biofunctionalized cGEL filler was assessed regarding building block integration, mechanical properties, in vitro cytotoxicity, and growth permissive effects on human adipose tissue-derived stem cells. A positive in vitro evaluation motivated further application of the filler material in a sciatic nerve defect. Compared to the empty conduit and pristine cGEL, the functionalization performed superior, though the autologous nerve graft remains the gold standard. In conclusion, LM11A-31 functionalized cGEL filler with extracellular matrix (ECM)-like characteristics and specific biochemical cues holds great potential to support PNR. PMID:28531139

Dual-Component Gelatinous Peptide/Reactive Oligomer Formulations as Conduit Material and Luminal Filler for Peripheral Nerve Regeneration.

PubMed

Kohn-Polster, Caroline; Bhatnagar, Divya; Woloszyn, Derek J; Richtmyer, Matthew; Starke, Annett; Springwald, Alexandra H; Franz, Sandra; Schulz-Siegmund, Michaela; Kaplan, Hilton M; Kohn, Joachim; Hacker, Michael C

2017-05-21

Toward the next generation of nerve guidance conduits (NGCs), novel biomaterials and functionalization concepts are required to address clinical demands in peripheral nerve regeneration (PNR). As a biological polymer with bioactive motifs, gelatinous peptides are promising building blocks. In combination with an anhydride-containing oligomer, a dual-component hydrogel system (cGEL) was established. First, hollow cGEL tubes were fabricated by a continuous dosing and templating process. Conduits were characterized concerning their mechanical strength, in vitro and in vivo degradation and biocompatibility. Second, cGEL was reformulated as injectable shear thinning filler for established NGCs, here tyrosine-derived polycarbonate-based braided conduits. Thereby, the formulation contained the small molecule LM11A-31. The biofunctionalized cGEL filler was assessed regarding building block integration, mechanical properties, in vitro cytotoxicity, and growth permissive effects on human adipose tissue-derived stem cells. A positive in vitro evaluation motivated further application of the filler material in a sciatic nerve defect. Compared to the empty conduit and pristine cGEL, the functionalization performed superior, though the autologous nerve graft remains the gold standard. In conclusion, LM11A-31 functionalized cGEL filler with extracellular matrix (ECM)-like characteristics and specific biochemical cues holds great potential to support PNR.

The effect of filler on the protein content and interferences in rubber latices

NASA Astrophysics Data System (ADS)

Ruhida, A. R.; Hassan, Aziz

2017-12-01

It is well known that the application of commercial fillers like calcium carbonate has widely been used in natural rubber latex (NRL) gloves as well as other dipped products such as balloons, condom and catheters. The main reason of adding the fillers into the rubber compound was as cheapening aid and to improve the end-product properties. Due to its functional benefit, many studies have been conducted on the application and beneficial usage of fillers in natural rubber (NR) compounds and natural rubber latex (NRL) dipped goods namely gloves. However most of the studies were basically emphasizing on the effect of fillers on the physical properties and surface morphology of rubber. Not many studies have been conducted to investigate the effect of filler on the protein content in NRL products. Earlier work by other workers has only been concentrating on the effect of nano-sized calcium carbonate fillers in NR latex gloves. Because of the concern on the issue of latex protein allergy; it is thus important to study the effect of filler on protein content and its interferences in the rubber lattices. This paper will seek to elaborate on the effect of filler content on the total protein and extractable protein (EP) content of NR latex films at various filler loadings before and after ageing. The effect of interferences by filler that was mixed into the NR latex on the total nitrogen and EP content were also measured and shown.

Filler features and their effects on wear and degree of conversion of particulate dental resin composites.

PubMed

Turssi, C P; Ferracane, J L; Vogel, K

2005-08-01

Based on the incomplete understanding on how filler features influence the wear resistance and monomer conversion of resin composites, this study sought to evaluate whether materials containing different shapes and combinations of size of filler particles would perform similarly in terms of three-body abrasion and degree of conversion. Twelve experimental monomodal, bimodal or trimodal composites containing either spherical or irregular shaped fillers ranging from 100 to 1500 nm were examined. Wear testings were conducted in the OHSU wear machine (n = 6) and quantified after 10(5) cycles using a profilometer. Degree of conversion (DC) was measured by FTIR spectrometry at the surface of the composites (n = 6). Data sets were analyzed using one-way Anova and Tukey's test at a significance level of 0.05. Filler size and geometry was found to have a significant effect on wear resistance and DC of composites. At specific sizes and combinations, the presence of small filler particles, either spherical or irregular, may aid in enhancing the wear resistance of composites, without compromising the percentage of reacted carbon double bonds.

Polymer Composite and Nanocomposite Dielectric Materials for Pulse Power Energy Storage †

PubMed Central

Barber, Peter; Balasubramanian, Shiva; Anguchamy, Yogesh; Gong, Shushan; Wibowo, Arief; Gao, Hongsheng; Ploehn, Harry J.; zur Loye, Hans-Conrad

2009-01-01

This review summarizes the current state of polymer composites used as dielectric materials for energy storage. The particular focus is on materials: polymers serving as the matrix, inorganic fillers used to increase the effective dielectric constant, and various recent investigations of functionalization of metal oxide fillers to improve compatibility with polymers. We review the recent literature focused on the dielectric characterization of composites, specifically the measurement of dielectric permittivity and breakdown field strength. Special attention is given to the analysis of the energy density of polymer composite materials and how the functionalization of the inorganic filler affects the energy density of polymer composite dielectric materials.

Reactive Diazonium-Modified Silica Fillers for High-Performance Polymers.

PubMed

Sandomierski, Mariusz; Strzemiecka, Beata; Chehimi, Mohamed M; Voelkel, Adam

2016-11-08

We describe a simple way of modification of three silica-based fillers with in situ generated 4-hydroxymethylbenzenediazonium salt ( + N 2 -C 6 H 4 -CH 2 OH). The rationale for using a hydroxyl-functionalized diazonium salt is that it provides surface-functionalized fillers that can react with phenolic resins. The modification of silica by diazonium salts was assessed using Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). FTIR spectroscopy permitted the tracking of benzene ring breathing and C-C. The absence of the characteristic N≡N stretching vibration in the 2200-2300 cm -1 range indicates the loss of the diazonium group. XPS results indicate a higher C/Si atomic ratio after the diazonium modification of fillers and the presence of π-π* C1s satellite peaks characteristic of the surface-tethered aromatic species. Adhesion of aryl layers to the silicas is excellent because they withstand harsh thermal and organic solvent treatments. Phenolic resins (used, for example, as binders in abrasive products) were filled with diazonium-modified silicas at 10-25 wt %. The reactivity of the fillers toward phenolic resins was evaluated by the determination of the flow distance. After annealing at 180 °C, the diazonium-modified silica/phenolic resin composites were mechanically tested using the three-point flexural method. The flexural strength was found to be up to 35% higher than that of the composites prepared without any diazonium salts. Diazonium-modified silica with surface-bound -CH 2 -OH groups is thus ideal reactive filler for phenolic resins. Such filler ensures interfacial chemical reactions with the matrix and imparts robust mechanical properties to the final composites. This specialty diazonium-modified silica will find potential application as fillers in the composites for the abrasive industry. More generally, aryl diazonium salts are a unique new series of compounds for tailoring the surface properties of fillers and tuning the physicochemical and mechanical properties of polymer composites.

Space thermal control development

NASA Technical Reports Server (NTRS)

Hoover, M. J.; Grodzka, P. G.; Oneill, M. J.

1971-01-01

The results of experimental investigations on a number of various phase change materials (PCMs) and PCMs in combination with metals and other materials are reported. The evaluations include the following PCM system performance characteristics: PCM and PCM/filler thermal diffusivities, the effects of long-term thermal cycling, PCM-container compatibility, and catalyst effectiveness and stability. Three PCMs demonstrated performance acceptable enough to be considered for use in prototype aluminum thermal control devices. These three PCMs are lithium nitrate trihydrate with zinc hydroxy nitrate catalyst, acetamide, and myristic acid. Of the fillers tested, aluminum honeycomb filler was found to offer the most increase in system thermal diffusivity.

Inactive Mineral Filler as a Stiffness Modulus Regulator in Foamed Bitumen-Modified Recycled Base Layers

NASA Astrophysics Data System (ADS)

Buczyński, Przemyslaw; Iwański, Marek

2017-10-01

The article presents the results of a cold recycled mix test with a foam bitumen including the addition of the inactive mineral filler as a dust of basalt. Basalt dust was derived from dedusting system by extraction of aggregates in the mine. Assessment of the impact of a basalt dust on the properties of a recycled base layer was carried out in terms of the amount of mineral filler (basalt) in the composition of the mineral mixture. This experiment involved a dosing of mineral filler in range from 5 to 20% with steps of 7.5% in the mineral mixture composition. The foamed bitumen was performed at optimum foaming process settings (ie. bitumen temperature, air pressure) and at 2.5% of the water content. The amount of a hydraulic binder as a Portland cement was 2.0%. The evaluation of rheological properties allowed to determine whether the addition of inactive mineral fillers can act as a stiffness modulus controller in the recycled base layer. The analysis of the rheological properties of a recycled base layer in terms of the amount of inactive fillers was performed in accordance with given standard EN 12697-26 Annex D. The study was carried out according to the direct tension-compression test methodology on cylindrical samples. The sample was subjected to the oscillatory sinusoidal strain ε0 < 25με. Studies carried out at a specific temperature set-points: - 7°C, 5°C, 13°C, 25°C and 40°C and at the frequency 0.1 Hz, 0.3 Hz, 1 Hz, 3 Hz, 10 Hz and 20 Hz. The obtained results allow to conclude that the use of an inactive filler can reduce the stiffness of an appropriate designed mixes of the cold recycled foundation. In addition, the analysis of the relation E‧-E″ showed a similar behaviour of a recycled base, regardless of the amount of inactive fillers in the mix composition, at high temperatures/high frequency of induced load.

Corrosion protection and adhesion properties of the epoxy coating applied on the steel substrate pre-treated by a sol-gel based silane coating filled with amino and isocyanate silane functionalized graphene oxide nanosheets

NASA Astrophysics Data System (ADS)

Parhizkar, Nafise; Ramezanzadeh, Bahram; Shahrabi, Taghi

2018-05-01

This research has focused on the effect of graphene oxide (GO) nano-fillers embedded in the sol-gel based silane coating on the corrosion protection and adhesion properties of the epoxy coating applied on the steel substrate pre-treated by silane coatings. For this purpose, a mixture of Methyltriethoxysilane (MTES) and Tetraethylorthosilicate (TEOS) silane precursors was used for preparation of composite matrix and the GO nanosheets, which are covalently functionalized with 3-(Triethoxysilyl)propyl isocyanate (TEPI, IGO nano-fillers) and 3-aminopropyltriethoxysilane (APTES, AGO nano-fillers), were used as filler. The GO, AGO and IGO nanosheets were characterized by Fourier Transform Infrared Spectroscopy (FT-IR), UV-Visible analysis and field emission-scanning electron microscopy techniques. The performance of the silane/epoxy coatings was investigated by pull-off adhesion, cathodic delamination, salt spray and electrochemical impedance spectroscopy (EIS) tests. Results revealed that AGO and IGO nano-fillers significantly improved the corrosion resistance and adhesion properties of the top epoxy coating due to better compatibility with silane matrix, excellent barrier properties and the formation of covalent bonds with the top epoxy coating.

Glans Penis Augmentation Using Hyaluronic Acid Gel as an Injectable Filler

PubMed Central

Kwak, Tae Il; Kim, Je Jong

2015-01-01

Glans penis augmentation (GPA) has received little attention from experts despite the existence of a subset of patients who may be dissatisfied with a small glans or poor tumescence of the glans during erection. Recently, GPA using an injectable filler or implantation of a graft or filler has been developed. Despite a demanding injection technique and inevitable uneven undulation of the glandular surface, GPA using injectable hyaluronic acid (HA) gel is a novel and useful therapy and an effective and safe procedure for soft tissue enhancement. For long-term presence of implants, timed supplementation can be used similar to that for fascial plasty. In complications such as mucosal necrosis of the glans penis, most cases occur from the use of non-HA gel or an unpurified form and misunderstanding of the management protocol for immediate side effects. Currently, GPA using injectable HA gel is not recommended in the International Society for Sexual Medicine guideline due to possible sensory loss. In a 5-year long-term follow-up of GPA by subcutaneous injection of HA gel, the residual volume of implants decreased by 15% of the maximal glandular circumference, but was still effective for alleviating the hypersensitivity of the glans penis in premature ejaculation patients. For efficacy in premature ejaculation, selection of appropriate candidates is the most important factor for success. GPA does not harm erectile function and is less invasive and irreversible compared to dorsal neurectomy. To refine the procedure, more interest and well-designed studies are required for the establishment of the procedure. PMID:26331121

Glans Penis Augmentation Using Hyaluronic Acid Gel as an Injectable Filler.

PubMed

Moon, Du Geon; Kwak, Tae Il; Kim, Je Jong

2015-08-01

Glans penis augmentation (GPA) has received little attention from experts despite the existence of a subset of patients who may be dissatisfied with a small glans or poor tumescence of the glans during erection. Recently, GPA using an injectable filler or implantation of a graft or filler has been developed. Despite a demanding injection technique and inevitable uneven undulation of the glandular surface, GPA using injectable hyaluronic acid (HA) gel is a novel and useful therapy and an effective and safe procedure for soft tissue enhancement. For long-term presence of implants, timed supplementation can be used similar to that for fascial plasty. In complications such as mucosal necrosis of the glans penis, most cases occur from the use of non-HA gel or an unpurified form and misunderstanding of the management protocol for immediate side effects. Currently, GPA using injectable HA gel is not recommended in the International Society for Sexual Medicine guideline due to possible sensory loss. In a 5-year long-term follow-up of GPA by subcutaneous injection of HA gel, the residual volume of implants decreased by 15% of the maximal glandular circumference, but was still effective for alleviating the hypersensitivity of the glans penis in premature ejaculation patients. For efficacy in premature ejaculation, selection of appropriate candidates is the most important factor for success. GPA does not harm erectile function and is less invasive and irreversible compared to dorsal neurectomy. To refine the procedure, more interest and well-designed studies are required for the establishment of the procedure.

Improving Multi-Functional Properties in Polymer Based Nano Composites by Interfacial

NASA Astrophysics Data System (ADS)

Tajaddod, Navid

Polymer nanocomposites (PNCs) have become an area of increasing interest for study in the field of polymer science and technology since the rise of nanotechnology research. Despite the significant amount of progress being made towards producing high quality PNC materials, improvement in the mechanical, electrical, thermal and other functional properties still remain a challenge. To date, these properties are only a fraction of the expected theoretical values predicted for these materials. Development of interfacial regions between the filler and matrix within the composite has been found to be an important focus in terms of processing. Proper interfacial control and development may ensure excellent interaction and property transfer between the filler and polymer matrix in addition to improvement of multi-functional properties of PNCs. The property-structure importance for the existence of the interfacial and interphase region within PNCs is discussed in this thesis work. Two specific PNC systems are selected for study as part of this dissertation in order to understand the effect of interfacial region development on influencing multi-functional property trends. Polyethylene (PE)/boron nitride (BN) and polyacrylonitrile (PAN)/carbon nanotube (CNT) composites were selected to investigate their mechanical performance and thermal and electrical conductivity properties, respectively. For these systems it was found that the interfacial region structure is directly related to the enhancement of the subsequent multi-functional properties.

Composite membranes for alkaline electrolysis based on polysulfone and mineral fillers

NASA Astrophysics Data System (ADS)

Burnat, Dariusz; Schlupp, Meike; Wichser, Adrian; Lothenbach, Barbara; Gorbar, Michal; Züttel, Andreas; Vogt, Ulrich F.

2015-09-01

Mineral-based membranes for high temperature alkaline electrolysis were developed by a phase inversion process with polysulfone as binder. The long-term stability of new mineral fillers: wollastonite, forsterite and barite was assessed by 8000 h-long leaching experiments (5.5 M KOH, 85 °C) combined with thermodynamic modelling. Barite has released only 6.22 10-4 M of Ba ions into the electrolyte and was selected as promising filler material, due to its excellent stability. Barite-based membranes, prepared by the phase inversion process, were further studied. The resistivity of these membranes in 5.5 M KOH was investigated as a function of membrane thickness and total porosity, hydrodynamic porosity as well as gas purities determined by conducting electrolysis at ambient conditions. It was found that a dense top layer resulting from the phase inversion process, shows resistivity values up to 451.0 ± 22 Ω cm, which is two orders of magnitude higher than a porous bulk membrane microstructure (3.89 Ω cm). Developed membranes provided hydrogen purity of 99.83 at 200 mA cm-2, which is comparable to previously used chrysotile membranes and higher than commercial state-of-the-art Zirfon 500utp membrane. These cost-effective polysulfone - barite membranes are promising candidates as asbestos replacement for commercial applications.

Method for controlling gas metal arc welding

DOEpatents

Smartt, Herschel B.; Einerson, Carolyn J.; Watkins, Arthur D.

1989-01-01

The heat input and mass input in a Gas Metal Arc welding process are controlled by a method that comprises calculating appropriate values for weld speed, filler wire feed rate and an expected value for the welding current by algorithmic function means, applying such values for weld speed and filler wire feed rate to the welding process, measuring the welding current, comparing the measured current to the calculated current, using said comparison to calculate corrections for the weld speed and filler wire feed rate, and applying corrections.

Modelling and operation strategies of DLR's large scale thermocline test facility (TESIS)

NASA Astrophysics Data System (ADS)

Odenthal, Christian; Breidenbach, Nils; Bauer, Thomas

2017-06-01

In this work an overview of the TESIS:store thermocline test facility and its current construction status will be given. Based on this, the TESIS:store facility using sensible solid filler material is modelled with a fully transient model, implemented in MATLAB®. Results in terms of the impact of filler site and operation strategies will be presented. While low porosity and small particle diameters for the filler material are beneficial, operation strategy is one key element with potential for optimization. It is shown that plant operators have to ponder between utilization and exergetic efficiency. Different durations of the charging and discharging period enable further potential for optimizations.

Effect of matrix chemical heterogeneity on effective filler interactions in model polymer nanocomposites

NASA Astrophysics Data System (ADS)

Hall, Lisa; Schweizer, Kenneth

2010-03-01

The microscopic Polymer Reference Interaction Site Model theory has been applied to spherical and rodlike fillers dissolved in three types of chemically heterogeneous polymer melts: alternating AB copolymer, random AB copolymers, and an equimolar blend of two homopolymers. In each case, one monomer species adsorbs more strongly on the filler mimicking a specific attraction, while all inter-monomer potentials are hard core which precludes macrophase or microphase separation. Qualitative differences in the filler potential-of-mean force are predicted relative to the homopolymer case. The adsorbed bound layer for alternating copolymers exhibits a spatial moduluation or layering effect but is otherwise similar to that of the homopolymer system. Random copolymers and the polymer blend mediate a novel strong, long-range bridging interaction between fillers at moderate to high adsorption strengths. The bridging strength is a non-monotonic function of random copolymer composition, reflecting subtle competing enthalpic and entropic considerations.

Nanostructured Materials Utilized in Biopolymer-based Plastics for Food Packaging Applications.

PubMed

Ghanbarzadeh, Babak; Oleyaei, Seyed Amir; Almasi, Hadi

2015-01-01

Most materials currently used for food packaging are nondegradable, generating environmental problems. Several biopolymers have been exploited to develop materials for ecofriendly food packaging. However, the use of biopolymers has been limited because of their usually poor mechanical and barrier properties, which may be improved by adding reinforcing compounds (fillers), forming composites. Most reinforced materials present poor matrix-filler interactions, which tend to improve with decreasing filler dimensions. The use of fillers with at least one nanoscale dimension (nanoparticles) produces nanocomposites. Nanoparticles have proportionally larger surface area than their microscale counterparts, which favors the filler-matrix interactions and the performance of the resulting material. Besides nanoreinforcements, nanoparticles can have other functions when added to a polymer, such as antimicrobial activity, etc. in this review paper, the structure and properties of main kinds of nanostructured materials which have been studied to use as nanofiller in biopolymer matrices are overviewed, as well as their effects and applications.

Reasons and remedies for the agglomeration of multilayered graphene and carbon nanotubes in polymers

PubMed Central

Atif, Rasheed

2016-01-01

Summary One of the main issues in the production of polymer nanocomposites is the dispersion state of filler as multilayered graphene (MLG) and carbon nanotubes (CNTs) tend to agglomerate due to van der Waals forces. The agglomeration can be avoided by using organic solvents, selecting suitable dispersion and production methods, and functionalizing the fillers. Another proposed method is the use of hybrid fillers as synergistic effects can cause an improvement in the dispersion state of the fillers. In this review article, various aspects of each process that can help avoid filler agglomeration and improve dispersion state are discussed in detail. This review article would be helpful for both current and prospective researchers in the field of MLG- and CNT-based polymer nanocomposites to achieve maximum enhancement in mechanical, thermal, and electrical properties of produced polymer nanocomposites. PMID:27826492

The Role of Nanofillers in Polymer Nanocomposites

NASA Astrophysics Data System (ADS)

Xu, Di

Polymer nanocomposites have been widely used in many fields. By introducing nanoparticles as fillers, researchers are able to get reinforced materials and new materials with novel properties, such as stronger mechanics, enhanced optical properties and improved conductivity. Though experimental techniques have rapidly advanced to enable better control of materials at atomic level, there is still a lack of a fundamental understanding of the dynamics and structure-properties relations in polymer nanocomposites. In this thesis, we use computer simulations to study the molecular structure and connections between microstate to macro properties of a variety of nanocomposites. Our goal is to understand the role of nanofillers in complex nanocomposite systems and to assist nanocomposite design. Nanoplatelet fillers, such as clays, have shown superior effects on the properties of polymer gels. We used molecular dynamic simulation to study nanoplatelet-filled composite gel system, in which short-range attraction exists between the polymer and nanoplatelet fillers. We show that the polymers and nanoplatelet fillers formed organic-inorganic networks with nanoplatelets acting as crosslink junctions, and the network eventually percolates the system as fillers reached a critical concentration. Stress auto-correlation and step-strain test were applied to investigate the mechanical properties; the results show the simulated composites changed from fluid-like to solid-like. The mechanical changes were consistent with the percolation transition, and gelation mechanism was therefore believed to be similar to those pure polymer physical gels. It was observed platelets aggregated into a local intercalation structure, which significantly differs from typical spherical fillers. This unique intercalation structure was examined by radial distribution function and ordering parameters. We discussed how intercalation would affect the properties of the platelet composites by comparing them with spherical fillers. Nanofillers have been widely used in polymer blends to improve the interfacial compatibility of otherwise immiscible polymers. In the second system, we investigated the interfacial behavior of binary polymer blends with different types of fillers. The interfacial tension and shear resistance were studied as a function of filler-polymer interaction, filler concentration and species of fillers. We found filler-polymer interaction is the key factor to improve the interfacial compatibility. The results show that nanofillers reduce both interfacial tension and interfacial slip at strong filler-polymer interaction. The effects of nanofillers however differ significantly from each other by their shapes. We analyzed the structure of nanofillers at the interface and their effects on the interfacial behaviors. The self-assembly of polymers into a columnar structure, while subject to a thin film environment, provides an economic route to fabricate polymer solar cell (PSC) with high conversion efficiency. In our work, we showed that two immiscible polymer segregates into to a percolating columnar structure when confined to a thin film. By adding nanofillers, with specific functionality, we can template the segregation of nanofillers to the polymer-polymer interface. We prove this process is surface tension driven and is a result that is particular for thin film geometries, where the thickness is under critical value. The results provide a theoretical basis for the column structure forming in a self-assembled PSC system, and can help to select polymer candidates that optimize PSC efficiency. These studies serve as theoretical guideline for engineering novel nanocomposites, and could lead to the design of materials with new and improved properties.

Cross-linguistic evidence for memory storage costs in filler-gap dependencies with wh-adjuncts

PubMed Central

Stepanov, Arthur; Stateva, Penka

2015-01-01

This study investigates processing of interrogative filler-gap dependencies in which the filler integration site or gap is not directly subcategorized by the verb. This is the case when the wh-filler is a structural adjunct such as how or when rather than subject or object. Two self-paced reading experiments in English and Slovenian provide converging cross-linguistic evidence that wh-adjuncts elicit a kind of memory storage cost similar to that previously shown in the literature for wh-arguments. Experiment 1 investigates the storage costs elicited by the adjunct when in Slovenian, and Experiment 2 the storage costs elicited by how quickly and why in English. The results support the class of theories of storage costs based on the metric in terms of incomplete phrase structure rules or incomplete syntactic head predictions. We also demonstrate that the endpoint of the storage cost for a wh-adjunct filler provides valuable processing evidence for its base structural position, the identification of which remains a rather murky issue in current grammatical research. PMID:26388806

Free radical scavenging properties of mannitol and its role as a constituent of hyaluronic acid fillers: a literature review.

PubMed

André, P; Villain, F

2017-08-01

Mannitol has both hydrating and antioxidant properties that make it an ideal excipient for use with hyaluronic acid (HA) fillers. This review examines the role of reactive oxygen species in the ageing process and their effects on both endogenous HA and HA products developed for aesthetic use. Evidence is presented to show that the free radical scavenging properties of mannitol provide it with a two-fold mechanism of action when combined with HA fillers: reducing the inflammation and swelling associated with the injection procedure itself, and preventing the degradation of the injected HA by free radicals. Mannitol also has a long- and well-established safety profile in both the food and pharmaceutical industry. Having established the rationale for using mannitol in combination with an HA filler, the products using this strategy are then reviewed. The addition of mannitol to HA fillers is a viable and safe option for improving both short- and long-term HA aesthetic effects. © 2016 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Many Body Effects on Particle Diffusion in Polymer Nanocomposites

NASA Astrophysics Data System (ADS)

Dell, Zachary E.; Schweizer, Kenneth S.

2014-03-01

Recent statistical mechanical theories of nanoparticle motion in polymer melts and networks have focused on the dilute particle limit. By combining PRISM theory predictions for microscopic structural correlations, and a new formulation of self-consistent dynamical mode coupling theory, we extend dilute theories to finite filler loading. As a minimalist model, the polymer dynamics are first assumed to be unperturbed by the presence of the nanoparticles. The long time particle diffusivity in unentangled and entangled melts is determined as a function of polymer tube diameter and radius of gyration, nanoparticle diameter, and polymer-filler attraction strength under both constant volume and constant pressure situations. The influence of nanocomposite statistical structure (depletion, steric stabilization, bridging) on dynamics is also investigated. Using recent theoretical developments for predicting tube diameters in nanocomposites, the consequences of filler-induced tube dilation on nanoparticle motion is established. In entangled melts, increasing filler loading first modestly speeds up diffusion, and then dramatically when the inter-filler separation becomes smaller than the tube diameter. At very high loadings, a filler glass transition is generically predicted.

A systematic review of filler agents for aesthetic treatment of HIV facial lipoatrophy (FLA).

PubMed

Jagdeo, Jared; Ho, Derek; Lo, Alex; Carruthers, Alastair

2015-12-01

HIV facial lipoatrophy (FLA) is characterized by facial volume loss. HIV FLA affects the facial contours of the cheeks, temples, and orbits, and is associated with social stigma. Although new highly active antiretroviral therapy medications are associated with less severe FLA, the prevalence of HIV FLA among treated individuals exceeds 50%. The goal of our systematic review is to examine published clinical studies involving the use of filler agents for aesthetic treatment of HIV FLA and to provide evidence-based recommendations based on published efficacy and safety data. A systematic review of the published literature was performed on July 1, 2015, on filler agents for aesthetic treatment of HIV FLA. Based on published studies, poly-L-lactic acid is the only filler agent with grade of recommendation: B. Other reviewed filler agents received grade of recommendation: C or D. Poly-L-lactic acid may be best for treatment over temples and cheeks, whereas calcium hydroxylapatite, with a Food and Drug Administration indication of subdermal implantation, may be best used deeply over bone for focal enhancement. Additional long-term randomized controlled trials are necessary to elucidate the advantages and disadvantages of fillers that have different biophysical properties, in conjunction with cost-effectiveness analysis, for treatment of HIV FLA. Published by Elsevier Inc.

Method for controlling gas metal arc welding

DOEpatents

Smartt, H.B.; Einerson, C.J.; Watkins, A.D.

1987-08-10

The heat input and mass input in a Gas Metal Arc welding process are controlled by a method that comprises calculating appropriate values for weld speed, filler wire feed rate and an expected value for the welding current by algorithmic function means, applying such values for weld speed and filler wire feed rate to the welding process, measuring the welding current, comparing the measured current to the calculated current, using said comparison to calculate corrections for the weld speed and filler wire feed rate, and applying corrections. 3 figs., 1 tab.

Morphological characterization of ceramic fillers made from Indonesian natural sand as restorative dental materials

NASA Astrophysics Data System (ADS)

Karlina, E.; Susra, S.; Fatmala, Y.; Hartoyo, H. M.; Takarini, V.; Usri, K.; Febrida, R.; Djustiana, N.; Panatarani, C.; Joni, I. M.

2018-02-01

Dental composite as restorative dental materials can be reinforced using ceramic fillers. Homogeneous distribution of filler particles shall improve its mechanical properties. This paper presents the results of the preliminary study on the ZrO2-Al2O3-SiO2 ceramic fillers made from Indonesian natural sand that can increase the mechanical properties of dental composite. The synthesis was done using zirconium silicate sand (ZrSiO4) and aluminium oxide (Al2O3) precursors, which dissolved together with 70:30 weight ratios. Two types of sand were used: (1) manufactured sand (mesh #80) and (2) natural sand (mesh #400). The samples then heated in the furnace at 1100 °C for 8 hours. The morphological characterization was then evaluated using JEOL Scanning Electron Microscope (SEM) for the surface structure that analyze particles size and distribution. Ceramic fillers made from natural sand is homogenous, well distributed with average particle size of 5-10 µm. Comparably, ceramic filler made from the manufactured sand is heterogeneous, poorly distributed and appear as agglomerates with average particle size are 30-50 µm. The results suggest that ceramic fillers made from natural sand demonstrate better character to represent as a functional restorative dental material.

Electrical conduction of a XLPE nanocomposite

NASA Astrophysics Data System (ADS)

Park, Yong-Jun; Sim, Jae-Yong; Lim, Kee-Joe; Nam, Jin-Ho; Park, Wan-Gi

2014-07-01

The resistivity, breakdown strength, and formation of space charges are very important factors for insulation design of HVDC cable. It is known that a nano-sized metal-oxide inorganic filler reduces the formation of space charges in the polymer nanocomposite. Electrical conduction of cross-linked polyethylene(XLPE) nanocomposite insulating material is investigated in this paper. The conduction currents of two kinds of XLPE nanocomposites and XLPE without nano-filler were measured at temperature of 303 ~ 363 K under the applied electric fields of 10 ~ 50 kV/mm. The current of the nanocomposite specimen is smaller than that of XLPE specimen without nano-filler. The conduction mechanism may be explained in terms of Schottky emission and multi-core model.

Epoxy Resin Composite Based on Functional Hybrid Fillers

PubMed Central

Oleksy, Mariusz; Szwarc-Rzepka, Karolina; Heneczkowski, Maciej; Oliwa, Rafał; Jesionowski, Teofil

2014-01-01

A study was carried out involving the filling of epoxy resin (EP) with bentonites and silica modified with polyhedral oligomeric silsesquioxane (POSS). The method of homogenization and the type of filler affect the functional and canceling properties of the composites was determined. The filler content ranged from 1.5% to 4.5% by mass. The basic mechanical properties of the hybrid composites were found to improve, and, in particular, there was an increase in tensile strength by 44%, and in Charpy impact strength by 93%. The developed hybrid composites had characteristics typical of polymer nanocomposites modified by clays, with a fine plate morphology of brittle fractures observed by SEM, absence of a plate separation peak in Wide Angles X-ray Scattering (WAXS) curves, and an exfoliated structure observed by TEM. PMID:28788177

A compound scaffold with uniform longitudinally oriented guidance cues and a porous sheath promotes peripheral nerve regeneration in vivo.

PubMed

Huang, Liangliang; Zhu, Lei; Shi, Xiaowei; Xia, Bing; Liu, Zhongyang; Zhu, Shu; Yang, Yafeng; Ma, Teng; Cheng, Pengzhen; Luo, Kai; Huang, Jinghui; Luo, Zhuojing

2018-03-01

Scaffolds with inner fillers that convey directional guidance cues represent promising candidates for nerve repair. However, incorrect positioning or non-uniform distribution of intraluminal fillers might result in regeneration failure. In addition, proper porosity (to enhance nutrient and oxygen exchange but prevent fibroblast infiltration) and mechanical properties (to ensure fixation and to protect regenerating axons from compression) of the outer sheath are also highly important for constructing advanced nerve scaffolds. In this study, we constructed a compound scaffold using a stage-wise strategy, including directionally freezing orientated collagen-chitosan (O-CCH) filler, electrospinning poly(ε-caprolactone) (PCL) sheaths and assembling O-CCH/PCL scaffolds. Based on scanning electron microscopy (SEM) and mechanical tests, a blend of collagen/chitosan (1:1) was selected for filler fabrication, and a wall thickness of 400 μm was selected for PCL sheath production. SEM and three-dimensional (3D) reconstruction further revealed that the O-CCH filler exhibited a uniform, longitudinally oriented microstructure (over 85% of pores were 20-50 μm in diameter). The electrospun PCL porous sheath with pore sizes of 6.5 ± 3.3 μm prevented fibroblast invasion. The PCL sheath exhibited comparable mechanical properties to commercially available nerve conduits, and the O-CCH filler showed a physiologically relevant substrate stiffness of 2.0 ± 0.4 kPa. The differential degradation time of the filler and sheath allows the O-CCH/PCL scaffold to protect regenerating axons from compression stress while providing enough space for regenerating nerves. In vitro and in vivo studies indicated that the O-CCH/PCL scaffolds could promote axonal regeneration and Schwann cell migration. More importantly, functional results indicated that the CCH/PCL compound scaffold induced comparable functional recovery to that of the autograft group at the end of the study. Our findings demonstrated that the O-CCH/PCL scaffold with uniform longitudinal guidance filler and a porous sheath exhibits favorable properties for clinical use and promotes nerve regeneration and functional recovery. The O-CCH/PCL scaffold provides a promising new path for developing an optimal therapeutic alternative for peripheral nerve reconstruction. Scaffolds with inner fillers displaying directional guidance cues represent a promising candidate for nerve repair. However, further clinical translation should pay attention to the problem of non-uniform distribution of inner fillers, the porosity and mechanical properties of the outer sheath and the morphological design facilitating operation. In this study, a stage-wise fabrication strategy was used, which made it possible to develop an O-CCH/PCL compound scaffold with a uniform longitudinally oriented inner filler and a porous outer sheath. The uniform distribution of the pores in the O-CCH/PCL scaffold provides a solution to resolve the problem of non-uniform distribution of inner fillers, which impede the clinical translation of scaffolds with longitudinal microstructured fillers, especially for aligned-fiber-based scaffolds. In vitro and in vivo studies indicated that the O-CCH/PCL scaffolds could provide topographical cues for axonal regeneration and SC migration, which were not found for random scaffolds (with random microstructure resemble sponge-based scaffolds). The electrospun porous PCL sheath of the O-CCH/PCL scaffold not only prevented fibroblast infiltration, but also satisfied the mechanical requirements for clinical use, paving the way for clinical translation. The differential degradation time of the O-CCH filler and the PCL sheath makes O-CCH/PCL scaffold able to provide long protection for regenerating axons from compression stress, but enough space for regenerating nerve. These findings highlight the possibility of developing an optimal therapeutic alternative for nerve defects using the O-CCH/PCL scaffold. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Treatment of Soft Tissue Filler Complications: Expert Consensus Recommendations.

PubMed

Urdiales-Gálvez, Fernando; Delgado, Nuria Escoda; Figueiredo, Vitor; Lajo-Plaza, José V; Mira, Mar; Moreno, Antonio; Ortíz-Martí, Francisco; Del Rio-Reyes, Rosa; Romero-Álvarez, Nazaret; Del Cueto, Sofía Ruiz; Segurado, María A; Rebenaque, Cristina Villanueva

2018-04-01

Dermal fillers have been increasingly used in minimally invasive facial esthetic procedures. This widespread use has led to a rise in reports of associated complications. The aim of this expert consensus report is to describe potential adverse events associated with dermal fillers and to provide guidance on their treatment and avoidance. A multidisciplinary group of experts in esthetic treatments convened to discuss the management of the complications associated with dermal fillers use. A search was performed for English, French, and Spanish language articles in MEDLINE, the Cochrane Database, and Google Scholar using the search terms "complications" OR "soft filler complications" OR "injectable complications" AND "dermal fillers" AND "Therapy". An initial document was drafted by the Coordinating Committee, and it was reviewed and modified by the experts, until a final text was agreed upon and validated. The panel addressed consensus recommendations about the classification of filler complications according to the time of onset and about the clinical management of different complications including bruising, swelling, edema, infections, lumps and bumps, skin discoloration, and biofilm formation. Special attention was paid to vascular compromise and retinal artery occlusion. Clinicians should be fully aware of the signs and symptoms related to complications and be prepared to confidently treat them. Establishing action protocols for emergencies, with agents readily available in the office, would reduce the severity of adverse outcomes associated with injection of hyaluronic acid fillers in the cosmetic setting. This document seeks to lay down a set of recommendations and to identify key issues that may be useful for clinicians who are starting to use dermal fillers. Additionally, this document provides a better understanding about the diagnoses and management of complications if they do occur. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Electron tomography provides a direct link between the Payne effect and the inter-particle spacing of rubber composites

PubMed Central

Staniewicz, Lech; Vaudey, Thomas; Degrandcourt, Christophe; Couty, Marc; Gaboriaud, Fabien; Midgley, Paul

2014-01-01

Rubber-filler composites are a key component in the manufacture of tyres. The filler provides mechanical reinforcement and additional wear resistance to the rubber, but it in turn introduces non-linear mechanical behaviour to the material which most likely arises from interactions between the filler particles, mediated by the rubber matrix. While various studies have been made on the bulk mechanical properties and of the filler network structure (both imaging and by simulations), there presently does not exist any work directly linking filler particle spacing and mechanical properties. Here we show that using STEM tomography, aided by a machine learning image analysis procedure, to measure silica particle spacings provides a direct link between the inter-particle spacing and the reduction in shear modulus as a function of strain (the Payne effect), measured using dynamic mechanical analysis. Simulations of filler network formation using attractive, repulsive and non-interacting potentials were processed using the same method and compared with the experimental data, with the net result being that an attractive inter-particle potential is the most accurate way of modelling styrene-butadiene rubber-silica composite formation. PMID:25487130

Magnetic and elastic anisotropy in magnetorheological elastomers using nickel-based nanoparticles and nanochains

DOE Office of Scientific and Technical Information (OSTI.GOV)

Landa, Romina A.; Soledad Antonel, Paula; Ruiz, Mariano M.

2013-12-07

Nickel (Ni) based nanoparticles and nanochains were incorporated as fillers in polydimethylsiloxane (PDMS) elastomers and then these mixtures were thermally cured in the presence of a uniform magnetic field. In this way, macroscopically structured-anisotropic PDMS-Ni based magnetorheological composites were obtained with the formation of pseudo-chains-like structures (referred as needles) oriented in the direction of the applied magnetic field when curing. Nanoparticles were synthesized at room temperature, under air ambient atmosphere (open air, atmospheric pressure) and then calcined at 400 °C (in air atmosphere also). The size distribution was obtained by fitting Small Angle X-ray Scattering (SAXS) experiments with a polydisperse hardmore » spheres model and a Schulz-Zimm distribution, obtaining a size distribution centered at (10.0 ± 0.6) nm with polydispersivity given by σ = (8.0 ± 0.2) nm. The SAXS, X-ray powder diffraction, and Transmission Electron Microscope (TEM) experiments are consistent with single crystal nanoparticles of spherical shape (average particle diameter obtained by TEM: (12 ± 1) nm). Nickel-based nanochains (average diameter: 360 nm; average length: 3 μm, obtained by Scanning Electron Microscopy; aspect ratio = length/diameter ∼ 10) were obtained at 85 °C and ambient atmosphere (open air, atmospheric pressure). The magnetic properties of Ni-based nanoparticles and nanochains at room temperature are compared and discussed in terms of surface and size effects. Both Ni-based nanoparticles and nanochains were used as fillers for obtaining the PDMS structured magnetorheological composites, observing the presence of oriented needles. Magnetization curves, ferromagnetic resonance (FMR) spectra, and strain-stress curves of low filler's loading composites (2% w/w of fillers) were determined as functions of the relative orientation with respect to the needles. The results indicate that even at low loadings it is possible to obtain magnetorheological composites with anisotropic properties, with larger anisotropy when using nanochains. For instance, the magnetic remanence, the FMR field, and the elastic response to compression are higher when measured parallel to the needles (about 30% with nanochains as fillers). Analogously, the elastic response is also anisotropic, with larger anisotropy when using nanochains as fillers. Therefore, all experiments performed confirm the high potential of nickel nanochains to induce anisotropic effects in magnetorheological materials.« less

Effect of various filler types on the properties of porous asphalt mixture

NASA Astrophysics Data System (ADS)

Shukry, Nurul Athma Mohd; Hassan, Norhidayah Abdul; Ezree Abdullah, Mohd; Rosli Hainin, Mohd; Yusoff, Nur Izzi Md; Putra Jaya, Ramadhansyah; Mohamed, Azman

2018-04-01

The open structure of porous asphalt exposes a large surface area to the effects of air and water, which accelerates the oxidation rate and affects the coating properties of the binder. These factors may influence the adhesive strength of the binder-aggregate and lead to cohesive failure within the binder film, contributing to aggregate stripping and moisture damage. The addition of fillers in asphalt mixtures has been identified to stiffen the asphalt binder and improve mixture strength. This study investigates the effect of various filler types (hydrated lime, cement, and diatomite) on the properties of porous asphalt. Compacted samples of porous asphalt were prepared using Superpave gyratory compactor at the target air void content of 21%. Each sample was incorporated with 2% of filler and polymer-modified binder of PG76. The morphology and chemical composition of fillers were investigated with a field emission scanning electron microscope (FESEM) and energy dispersive X-ray (EDX) analysis. The properties of porous asphalt were evaluated in terms of permeability, abrasion loss, resilient modulus, and indirect tensile strength. All mixtures were found to show high permeability rates. Mixtures with hydrated lime exhibited lower abrasion loss compared to mixtures with cement and diatomite. The use of diatomite increases the resistance of the mixtures to rutting and moisture damage compared to other fillers as shown by the enhanced resilient modulus and indirect tensile strength.

Enhanced lithium battery with polyethylene oxide-based electrolyte containing silane-Al2 O3 ceramic filler.

PubMed

Zewde, Berhanu W; Admassie, Shimelis; Zimmermann, Jutta; Isfort, Christian Schulze; Scrosati, Bruno; Hassoun, Jusef

2013-08-01

A solid polymer electrolyte prepared by using a solvent-free, scalable technique is reported. The membrane is formed by low-energy ball milling followed by hot-pressing of dry powdered polyethylene oxide polymer, LiCF3 SO3 salt, and silane-treated Al2 O3 (Al2 O3 -ST) ceramic filler. The effects of the ceramic fillers on the properties of the ionically conducting solid electrolyte membrane are characterized by using electrochemical impedance spectroscopy, XRD, differential scanning calorimeter, SEM, and galvanostatic cycling in lithium cells with a LiFePO4 cathode. We demonstrate that the membrane containing Al2 O3 -ST ceramic filler performs well in terms of ionic conductivity, thermal properties, and lithium transference number. Furthermore, we show that the lithium cells, which use the new electrolyte together with the LiFePO4 electrode, operate within 65 and 90 °C with high efficiency and long cycle life. Hence, the Al2 O3 -ST ceramic can be efficiently used as a ceramic filler to enhance the performance of solid polymer electrolytes in lithium batteries. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Steam Cured Self-Consolidating Concrete and the Effects of Limestone Filler

NASA Astrophysics Data System (ADS)

Aqel, Mohammad A.

The purpose of this thesis is to determine the effect and the mechanisms associated with replacing 15% of the cement by limestone filler on the mechanical properties and durability performance of self-consolidating concrete designed and cured for precast/prestressed applications. This study investigates the role of limestone filler on the hydration kinetics, mechanical properties (12 hours to 300 days), microstructural and durability performance (rapid chloride permeability, linear shrinkage, sulfate resistance, freeze-thaw resistance and salt scaling resistance) of various self-consolidating concrete mix designs containing 5% silica fume and steam cured at a maximum holding temperature of 55°C. This research also examines the resistance to delayed ettringite formation when the concrete is steam cured at 70°C and 82°C and its secondary consequences on the freeze-thaw resistance. The effect of several experimental variables related to the concrete mix design and also the curing conditions are examined, namely: limestone filler fineness, limestone filler content, cement type, steam curing duration and steam curing temperature. In general, the results reveal that self-consolidating concrete containing 15% limestone filler, steam cured at 55°C, 70°C and 82°C, exhibited similar or superior mechanical and transport properties as well as long term durability performance compared to similar concrete without limestone filler. When the concrete is steam cured at 55°C, the chemical reactivity of limestone filler has an important role in enhancing the mechanical properties at 16 hours (compared to the concrete without limestone filler) and compensating for the dilution effect at 28 days. Although, at 300 days, the expansion of all concrete mixes are below 0.05%, the corresponding freeze-thaw durability factors vary widely and are controlled by the steam curing temperature and the chemical composition of the cement. Overall, the material properties indicate that the use of 15% limestone filler as cement replacement is a viable option for the precast/prestressed concrete applications, and in addition, would also have economic and environmental benefits.

Synthesis of Superabsorbent Polymer via Inverse Suspension Method: Effect of Carbon Filler

NASA Astrophysics Data System (ADS)

Zakaria, Munirah Ezzah Tuan; Shima Jamari, Saidatul; Ling, Yeong Yi; Ghazali, Suriati

2017-05-01

This paper studies on the effect of the addition of carbon filler towards the performance of superabsorbent polymer composite (SAPc). In this work, the SAPc was synthesized using inverse suspension polymerization method. The process involved two different solutions; dispersed phase which contains partially neutralized acrylic acid, acrylamide, APS and NN-Methylenebisacrylamide, and continuous phase which contains cyclohexane, span-80 and carbon filler (at different weight percent). The optimum SAPs and filler ratio was measured in terms of water retention in soil and characterized by Mastersizer, FTIR and SEM. Biodegradability of the polymer was determined by soil burial test and SAPc with 0.02% carbon has highest biodegradability rate. SAPc with 0.04wt% carbon showed the optimal water retention percentage among all the samples. The synthesized SAPc producing spherical shapes with parallel alignment due to the addition of carbon fiber. It can be concluded that the addition of carbon fiber able to enhance the performance of the SAP composite (SAPc).

Joining of ceramics for high performance energy systems. Mid-term progress report, August 1, 1979-March 31, 1980

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smeltzer, C E; Metcalfe, A G

The subject program is primarily an exploratory and demonstration study of the use of silicate glass-based adhesives for bonding silicon-base refractory ceramics (SiC, Si/sub 3/N/sub 4/). The projected application is 1250 to 2050/sup 0/F relaxing joint service in high-performance energy conversion systems. The five program tasks and their current status are as follows. Task 1 - Long-Term Joint Stability. Time-temperature-transformation studies of candidate glass adhesives, out to 2000 hours simulated service exposure, are half complete. Task 2 - Environmental and Service Effects on Joint Reliability. Start up delayed due to late delivery of candidate glass fillers and ceramic specimens. Taskmore » 3 - Viscoelastic Damping of Glass Bonded Ceramics. Promising results obtained over approximately the same range of glass viscosity required for joint relaxation function (10/sup 7.5/ to 10/sup 9.5/ poise). Work is 90% complete. Task 4 - Crack Arrest and Crack Diversion by Joints. No work started due to late arrival of materials. Task 5 - Improved Joining and Fabrication Methods. Significant work has been conducted in the area of refractory pre-glazing and the application and bonding of high-density candidate glass fillers (by both hand-artisan and slip-spray techniques). Work is half complete.« less

Effects of age condition on the distribution and integrity of inorganic fillers in dental resin composites.

PubMed

D'Alpino, Paulo Henrique Perlatti; Svizero, Nádia da Rocha; Bim Júnior, Odair; Valduga, Claudete Justina; Graeff, Carlos Frederico de Oliveira; Sauro, Salvatore

2016-06-01

The aim of this study is to evaluate the distribution of the filler size along with the zeta potential, and the integrity of silane-bonded filler surface in different types of restorative dental composites as a function of the material age condition. Filtek P60 (hybrid composite), Filtek Z250 (small-particle filled composite), Filtek Z350XT (nanofilled composite), and Filtek Silorane (silorane composite) (3M ESPE) were tested at different stage condition (i.e., fresh/new, aged, and expired). Composites were submitted to an accelerated aging protocol (Arrhenius model). Specimens were obtained by first diluting each composite specimen in ethanol and then dispersed in potassium chloride solution (0.001 mol%). Composite fillers were characterized for their zeta potential, mean particle size, size distribution, via poly-dispersion dynamic light scattering. The integrity of the silane-bonded surface of the fillers was characterized by FTIR. The material age influenced significantly the outcomes; Zeta potential, filler characteristics, and silane integrity varied both after aging and expiration. Silorane presented the broadest filler distribution and lowest zeta potential. Nanofilled and silorane composites exhibited decreased peak intensities in the FTIR analysis, indicating a deficiency of the silane integrity after aging or expiry time. Regardless to the material condition, the hybrid and the small-particle-filled composites were more stable overtime as no significant alteration in filler size distribution, diameter, and zeta potential occurred. A deficiency in the silane integrity in the nanofilled and silorane composites seems to be affected by the material stage condition. The materials conditions tested in this study influenced the filler size distribution, the zeta potential, and integrity of the silane adsorbed on fillers in the nanofilled and silorane composites. Thus, this may result in a decrease of the clinical performance of aforementioned composites, in particular, if these are used after inappropriate storage conditions.

Elastomeric Cellular Structure Enhanced by Compressible Liquid Filler

NASA Astrophysics Data System (ADS)

Sun, Yueting; Xu, Xiaoqing; Xu, Chengliang; Qiao, Yu; Li, Yibing

2016-05-01

Elastomeric cellular structures provide a promising solution for energy absorption. Their flexible and resilient nature is particularly relevant to protection of human bodies. Herein we develop an elastomeric cellular structure filled with nanoporous material functionalized (NMF) liquid. Due to the nanoscale infiltration in NMF liquid and its interaction with cell walls, the cellular structure has a much enhanced mechanical performance, in terms of loading capacity and energy absorption density. Moreover, it is validated that the structure is highly compressible and self-restoring. Its hyper-viscoelastic characteristics are elucidated.

Effect of Storage in Distilled Water for Three Months on the Antimicrobial Properties of Poly(methyl methacrylate) Denture Base Material Doped with Inorganic Filler

PubMed Central

Chladek, Grzegorz; Basa, Katarzyna; Mertas, Anna; Pakieła, Wojciech; Żmudzki, Jarosław; Bobela, Elżbieta; Król, Wojciech

2016-01-01

The colonization of poly(methyl methacrylate) (PMMA) denture base materials by pathogenic microorganisms is a major problem associated with the use of prostheses, and the incorporation of antimicrobial fillers is a method of improving the antimicrobial properties of these materials. Numerous studies have demonstrated the initial in vitro antimicrobial effectiveness of this type of material; however, reports demonstrating the stability of these fillers over longer periods are not available. In this study, silver sodium hydrogen zirconium phosphate was introduced into the powder component of a PMMA denture base material at concentrations of 0.25%, 0.5%, 1%, 2%, 4%, and 8% (w/w). The survival rates of the gram-positive bacterium Staphylococcus aureus, gram-negative bacterium Escherichia coli and yeast-type fungus Candida albicans were established after fungal or bacterial suspensions were incubated with samples that had been previously stored in distilled water. Storage over a three-month period led to the progressive reduction of the initial antimicrobial properties. The results of this study suggest that additional microbiological tests should be conducted for materials that are treated with antimicrobial fillers and intended for long-term use. Future long-term studies of the migration of silver ions from the polymer matrix and the influence of different media on this ion emission are required. PMID:28773451

Differences in fundamental and functional properties of HPMC co-processed fillers prepared by fluid-bed coating and spray drying.

PubMed

Dong, QianQian; Zhou, MiaoMiao; Lin, Xiao; Shen, Lan; Feng, Yi

2018-07-01

This study aimed to develop novel co-processed tablet fillers based on the principle of particle engineering for direct compaction and to compare the characteristics of co-processed products obtained by fluid-bed coating and co-spray drying, respectively. Water-soluble mannitol and water-insoluble calcium carbonate were selected as representative fillers for this study. Hydroxypropyl methylcellulose (HPMC), serving as a surface property modifier, was distributed on the surface of primary filler particles via the two co-processing methods. Both fundamental and functional properties of the products were comparatively investigated. The results showed that functional properties of the fillers, like flowability, compactibility, and drug-loading capacity, were effectively improved by both co-processing methods. However, fluid-bed coating showed greater advantages over co-spray drying in some aspects, which was mainly attributed to the remarkable differences in some fundamental properties of co-processed powders, like particle size, surface topology, and particle structure. For example, the more irregular surface and porous structure induced by fluid-bed coating could contribute to better compaction properties and lower lubricant sensitivity due to the increasing contact area and mechanical interlocking between particles under pressure. More effective surface distribution of HPMC during fluid-bed coating was also a contributor. In addition, such a porous agglomerate structure could also reduce the separation of drug and excipients after mixing, resulting in the improvement in drug loading capacity and tablet uniformity. In summary, fluid-bed coating appears to be more promising for co-processing than spray drying in some aspects, and co-processed excipients produced by it have a great prospect for further investigations and development. Copyright © 2018 Elsevier B.V. All rights reserved.

Multifunctional Graphene-Silicone Elastomer Nanocomposite, Method of Making the Same, and Uses Thereof

NASA Technical Reports Server (NTRS)

Prud'Homme, Robert K. (Inventor); Pan, Shuyang (Inventor); Aksay, Ilhan A. (Inventor)

2018-01-01

A nanocomposite composition having a silicone elastomer matrix having therein a filler loading of greater than 0.05 wt %, based on total nanocomposite weight, wherein the filler is functional graphene sheets (FGS) having a surface area of from 300 sq m/g to 2630 sq m2/g; and a method for producing the nanocomposite and uses thereof.

Novel sulfonated polyimide/zwitterionic polymer-functionalized graphene oxide hybrid membranes for vanadium redox flow battery

NASA Astrophysics Data System (ADS)

Cao, Li; Kong, Lei; Kong, Lingqian; Zhang, Xingxiang; Shi, Haifeng

2015-12-01

Hybrid membranes (SPI/ZGO) composed of sulfonated polyimide (SPI) and zwitterionic polymer-functionalized graphene oxide (ZGO) are fabricated via a solution-casting method for vanadium redox flow battery (VRB). Successful preparation of ZGO fillers and SPI/ZGO hybrid membranes are demonstrated by FT-IR, XPS and SEM, indicating that ZGO fillers is homogeneously dispersed into SPI matrix. Through controlling the interfacial interaction between SPI matrix and ZGO fillers, the physicochemical properties, e.g., vanadium ion barrier and proton transport pathway, of hybrid membranes are tuned via the zwitterionic acid-base interaction in the hybrid membrane, showing a high ion selectivity and good stability with the incorporated ZGO fillers. SPI/ZGO-4 hybrid membrane proves a higher cell efficiencies (CE: 92-98%, EE: 65-79%) than commercial Nafion 117 membrane (CE: 89-94%, EE: 59-70%) for VRB application at 30-80 mA cm-2. The assembled VRB with SPI/ZGO-4 membrane presents a stable cycling charge-discharge performance over 280 times, which demonstrates its excellent chemical stability under the strong acidic and oxidizing conditions. SPI/ZGO hybrid membranes show a brilliant perspective for VRB application.

Optimization and control of dynamic percolationin nanostructured silicon oils

NASA Astrophysics Data System (ADS)

Badard, Mathieu; Combessis, Anthony; Allais, Arnaud; Flandin, Lionel

2017-06-01

The addition of carbonaceous fillers in polymers allows the conception of composites with optimized electrical properties. The conductivity of such material depends of the fillers structuration in matrix, especially the presence of percolated network. The objective of this paper is to understand the main aggregation mechanisms of carbon nanotubes in different media. The structuration of these filler network is probed by the use of electrical and dielectrical measurements. The innovative part of our work lies in the use of liquid matrices, especially silicon oils, to overcome mechanical constraints present in polymers on the one hand and to simplify processing on the other hand. Our work has revealed a filler aggregation over time, well known as dynamic percolation. Conductivity has been modeled as a function of time and filler content from Kirkpatrick equation. The further use of an electrical field led to conductivity enhancement as well as a decrease in percolation threshold. Finally, a study of intrinsic parameters of matrix has shown a strong effect of viscosity and surface tension on nanotubes aggregation. Contribution to the topical issue "Electrical Engineering Symposium (SGE 2016)", edited by Adel Razek

Influence of Filler Pore Structure and Polymer on the Performance of MOF-Based Mixed-Matrix Membranes for CO2 Capture.

PubMed

Sabetghadam, Anahid; Liu, Xinlei; Benzaqui, Marvin; Gkaniatsou, Effrosyni; Orsi, Angelica; Lozinska, Magdalena M; Sicard, Clemence; Johnson, Timothy; Steunou, Nathalie; Wright, Paul A; Serre, Christian; Gascon, Jorge; Kapteijn, Freek

2018-06-04

To gain insight into the influence of metal-organic framework (MOF) fillers and polymers on membrane performance, eight different composites were studied by combining four MOFs and two polymers. MOF materials (NH 2 -MIL-53(Al), MIL-69(Al), MIL-96(Al) and ZIF-94) with various chemical functionalities, topologies, and dimensionalities of porosity were employed as fillers, and two typical polymers with different permeability-selectivity properties (6FDA-DAM and Pebax) were selected as matrices. The best-performing MOF-polymer composites were prepared by loading 25 wt % of MIL-96(Al) as filler, which improved the permeability and selectivity of 6FDA-DAM to 32 and 10 %, while for Pebax they were enhanced to 25 and 18 %, respectively. The observed differences in membrane performance in the separation of CO 2 from N 2 are explained on the basis of gas solubility, diffusivity properties, and compatibility between the filler and polymer phases. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Study of piezoelectric filler on the properties of PZT-PVDF composites

NASA Astrophysics Data System (ADS)

Matei, Alina; Å¢ucureanu, Vasilica; Vlǎzan, Paulina; Cernica, Ileana; Popescu, Marian; RomaniÅ£an, Cosmin

2017-12-01

The ability to obtain composites with desired functionalities is based on advanced knowledge of the processes synthesis and of the structure of piezoceramic materials, as well the incorporation of different fillers in selected polymer matrix. Polyvinylidene fluoride (PVDF) is a fluorinated polymer with excellent mechanical and electric properties, which it was chosen as matrix due to their applications in a wide range of industrial fields [1-4]. The present paper focuses on the development of composites based on PZT particles as filler obtained by conventional methods and PVDF as polymer matrix. The synthesis of PVDF-PZT composites was obtained by dispersing the ceramic powders in a solution of PVDF in N-methyl-pyrrolidone (NMP) under mechanical mixing and ultrasonication, until a homogenous mixture is obtained. The properties of the piezoceramic fillers before and after embedding into the polymeric matrix were investigated by Fourier transform infrared spectrometry, field emission scanning electron microscopy and X-ray diffraction. In the FTIR spectra, appear a large number of absorption bands which are exclusive of the phases from PVDF matrix confirming the total embedding of PZT filler into matrix. Also, the XRD pattern of the composites has confirmed the presence of crystalline phases of PVDF and the ceramic phase of PZT. The SEM results showed a good distribution of fillers in the matrix.

Efficacy and Safety of a Hyaluronic Acid Filler to Correct Aesthetically Detracting or Deficient Features of the Asian Nose: A Prospective, Open-Label, Long-Term Study

PubMed Central

Liew, Steven; Scamp, Terrence; de Maio, Mauricio; Halstead, Michael; Johnston, Nicole; Silberberg, Michael; Rogers, John D.

2016-01-01

Background There is increasing interest among patients and plastic surgeons for alternatives to rhinoplasty, a common surgical procedure performed in Asia. Objectives To evaluate the safety, efficacy, and longevity of a hyaluronic acid filler in the correction of aesthetically detracting or deficient features of the Asian nose. Methods Twenty-nine carefully screened Asian patients had their noses corrected with the study filler (Juvéderm VOLUMA [Allergan plc, Dublin, Ireland] with lidocaine injectable gel), reflecting individualized treatment goals and utilizing a standardized injection procedure, and were followed for over 12 months. Results A clinically meaningful correction (≥1 grade improvement on the Assessment of Aesthetic Improvement Scale) was achieved in 27 (93.1%) patients at the first follow-up visit. This was maintained in 28 (96.6%) patients at the final visit, based on the independent assessments of a central non-injecting physician and the patients. At this final visit, 23 (79.3%) patients were satisfied or very satisfied with the study filler and 25 (86.2%) would recommend it to others. In this small series of patients, there were no serious adverse events (AEs), with all treatment-related AEs being mild to moderate, transient injection site reactions, unrelated to the study filler. Conclusions Using specific eligibility criteria, individualized treatment goals, and a standardized injection procedure, the study filler corrected aesthetically detracting or deficient features of the Asian nose, with the therapeutic effects lasting for over 12 months, consistent with a high degree of patient satisfaction. This study supports the safety and efficacy of this HA filler for specific nose augmentation procedures in selected Asian patients. Level of Evidence: 3 Therapeutic PMID:27301371

Comparing Efficacy and Costs of Four Facial Fillers in Human Immunodeficiency Virus-Associated Lipodystrophy: A Clinical Trial.

PubMed

Vallejo, Alfonso; Garcia-Ruano, Angela A; Pinilla, Carmen; Castellano, Michele; Deleyto, Esther; Perez-Cano, Rosa

2018-03-01

The objective of this study was to evaluate and compare the safety and effectiveness of four different dermal fillers in the treatment of facial lipoatrophy secondary to human immunodeficiency virus. The authors conducted a clinical trial including 147 patients suffering from human immunodeficiency virus-induced lipoatrophy treated with Sculptra (poly-L-lactic acid), Radiesse (calcium hydroxylapatite), Aquamid (polyacrylamide), or autologous fat. Objective and subjective changes were evaluated during a 24-month follow-up. Number of sessions, total volume injected, and overall costs of treatment were also analyzed. A comparative cost-effectiveness analysis of the treatment options was performed. Objective improvement in facial lipoatrophy, assessed by the surgeon in terms of changes from baseline using the published classification of Fontdevila, was reported in 53 percent of the cases. Patient self-evaluation showed a general improvement after the use of facial fillers. Patients reported being satisfied with the treatment and with the reduced impact of lipodystrophy on their quality of life. Despite the nonsignificant differences observed in the number of sessions and volume, autologous fat showed significantly lower costs than all synthetic fillers (p < 0.05). Surgical treatment of human immunodeficiency virus-associated facial lipoatrophy using dermal fillers is a safe and effective procedure that improves the aesthetic appearance and the quality of life of patients. Permanent fillers and autologous fat achieve the most consistent results over time, with lipofilling being the most cost-effective procedure.

Alice's adventures in um-derland: Psycholinguistic sources of variation in disfluency production

PubMed Central

Fraundorf, Scott H.; Watson, Duane G.

2013-01-01

This study tests the hypothesis that three common types of disfluency (fillers, silent pauses, and repeated words) reflect variance in what strategies are available to the production system for responding to difficulty in language production. Participants' speech in a storytelling paradigm was coded for the three disfluency types. Repeats occurred most often when difficult material was already being produced and could be repeated, but fillers and silent pauses occurred most when difficult material was still being planned. Fillers were associated only with conceptual difficulties, consistent with the proposal that they reflect a communicative signal whereas silent pauses and repeats were also related to lexical and phonological difficulties. These differences are discussed in terms of different strategies available to the language production system. PMID:25339788

A prospective study of non-surgical primary rhinoplasty using a polymethylmethacrylate injectable implant.

PubMed

Rivkin, Alexander

2014-03-01

Nonsurgical rhinoplasty involves the use of injectable fillers to improve the contours of the nose. It has become a widely practiced procedure since this author first popularized it in 2003. The use of permanent fillers in nonsurgical rhinoplasty has not been well documented, especially in this country. To demonstrate the safety and effectiveness of a polymethylmethacrylate (PMMA)-based filler for nonsurgical rhinoplasty. Eligible subjects underwent up to three injection sessions with a commercially available PMMA product and were followed for 1 year. Efficacy was assessed according to evaluator grading of subjects and digital image analysis of standardized photographs. Nineteen subjects were enrolled and followed to conclusion. Average improvement in global score was more than one point observed on day 90 and lasting through 1 year. Eight of 10 subjects showed improvement according to digital image analysis at 1 year. Subject satisfaction was high throughout the study. Adverse events were minimal and well tolerated. Filler rhinoplasty using a PMMA-based injectable filler is safe and effective. This is the first study documenting the use of PMMA for this indication. Longer-term follow-up is needed to demonstrate persistence of improvement. © 2013 by the American Society for Dermatologic Surgery, Inc. Published by Wiley Periodicals, Inc.

Multifunctional Graphene-Silicone Elastomer Nanocomposite, Method of Making the Same, and Uses Thereof

NASA Technical Reports Server (NTRS)

Aksay, Ilhan A. (Inventor); Pan, Shuyang (Inventor); Prud'Homme, Robert K. (Inventor)

2016-01-01

A nanocomposite composition having a silicone elastomer matrix having therein a filler loading of greater than 0.05 weight percentage, based on total nanocomposite weight, wherein the filler is functional graphene sheets (FGS) having a surface area of from 300 square meters per gram to 2630 square meters per gram; and a method for producing the nanocomposite and uses thereof.

AMTEC recirculating test cell component testing and operation

NASA Technical Reports Server (NTRS)

Underwood, M. L.; Sievers, R. K.; O'Connor, D.; Williams, R. M.; Jeffries-Nakamura, B.; Bankston, C. P.

1989-01-01

Alkali metal thermoelectric converter operation in a recirculating test cell (RTC), which requires a small electromagnetic pump (EM) and a high-temperature beta-double-prime alumina-solid-electrolyte (BASE)-to-metal seal, is discussed. The design of a pump and an active metal braze seal and the initial operation of a cell using these components are described. The pump delivered 0.25 cu cm/min against a 28-psia head. A braze seal system was selected after shear strength tests of Ta or Nb brazed to BASE by a variety of fillers including TiCuNi, TiNi, and TiNiCr. The TiCuNi filler was chosen for environment cell testing and showed no failure or observable degradation after short-term tests up to 1055 K. The pump and the Nb/TiCuNi/BASE seal were used in a test that demonstrated all the operational functions of the RTC for the first time. An increase in the radiation reduction factor at constant input power was observed, indicating that the condenser was being wet by sodium resulting in an increased reflectivity.

Antibacterial activity of resin composites containing surface pre-reacted glass-ionomer (S-PRG) filler.

PubMed

Miki, Saeki; Kitagawa, Haruaki; Kitagawa, Ranna; Kiba, Wakako; Hayashi, Mikako; Imazato, Satoshi

2016-09-01

A surface pre-reacted glass-ionomer (S-PRG) filler is a technology of interest for providing bio-functions to restorative materials. Resin composites containing S-PRG filler have been reported to show less plaque accumulation and reduced bacterial attachment. In this study, experimental resin composites containing S-PRG filler at various concentrations were fabricated, and the inhibitory effects on bacterial growth on their surface and the association of ions released from S-PRG filler with antibacterial activity were evaluated. Five kinds of experimental resin composites containing S-PRG filler at 0, 13.9, 27.3, 41.8, or 55.9 (vol.%) were fabricated. Streptococcus mutans was cultured on the cured discs for 18h to examine the growth of bacteria in contact with the surface of the experimental resins. The concentrations of Al(3+), BO3(3-), F(-), Na(+), SiO3(2-), or Sr(2+) released from each experimental resin into water were measured. The standardized solutions of each ion were prepared at the concentrations determined to be released from the experimental resin, and their inhibitory effects of single ion species on S. mutans growth were evaluated by using each standardized solution. Resin composites containing S-PRG filler at 13.9 (vol.%) or greater inhibited S. mutans growth on their surface. When S. mutans was incubated in the presence of six kinds of ions at the concentrations released from the resin composite containing S-PRG filler at 55.9 (vol.%), a significant reduction in bacterial number was observed for BO3(3-), F(-), Al(3+), and SiO3(2-). Among these four ions, BO3(3-) and F(-) demonstrated the strongest inhibitory effect on S. mutans growth. Our findings suggest that resin composites containing S-PRG filler inhibit the growth of S. mutans on their surface. BO3(3-), F(-), Al(3+) and SiO3(2-) released from S-PRG filler have the ability to inhibit S. mutans growth, and the inhibitory effects are mainly attributed to release of BO3(3-) and F(-). Copyright © 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

[Facial injections of hyaluronic acid-based fillers for malformations. Preliminary study regarding scar tissue improvement and cosmetic betterment].

PubMed

Franchi, G; Neiva-Vaz, C; Picard, A; Vazquez, M-P

2018-06-01

Cross-linked hyaluronic acid-based fillers have gained rapid acceptance for treating facial wrinkles, deep tissue folds and sunken areas due to aging. This study evaluates, in addition to space-filling properties, their effects on softness and elasticity as a secondary effect, following injection of 3 commercially available cross-linked hyaluronic acid-based fillers (15mg/mL, 17,5mg/mL and 20mg/mL) in patients presenting with congenital or acquired facial malformations. We started injecting gels of cross-linked hyaluronic acid-based fillers in those cases in 2013; we performed 46 sessions of injections in 32 patients, aged from 13-32. Clinical assessment was performed by the patient himself and by a plastic surgeon, 15 days after injections and 6-18 months later. Cross-linked hyaluronic acid-based fillers offered very subtle cosmetic results and supplemented surgery with a very high level of satisfaction of the patients. When injected in fibrosis, the first session enhanced softness and elasticity; the second session enhanced the volume. Cross-linked hyaluronic acid-based fillers fill sunken areas and better softness and elasticity of scar tissues. In addition to their well-understood space-filling function, as a secondary effect, the authors demonstrate that cross-linked hyaluronic acid-based fillers improve softness and elasticity of scarring tissues. Many experimental studies support our observations, showing that cross-linked hyaluronic acid stimulates the production of several extra-cellular matrix components, including dermal collagen and elastin. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Low-Thermal-Expansion Filled Polytetrafluoroethylene

NASA Technical Reports Server (NTRS)

Shapiro, Sanford S.

1989-01-01

PTFE made thermally compatible with aluminum without changing dielectric constant. Manufactured with fillers and pores to reduce coefficient of thermal expansion by factor of 6 to match aluminum. Material retains 2.1 dielectric constant of pure PTFE. Combines filler and micropore concepts. Particles and voids embedded in PTFE matrix function cooperatively. Particles take up compressive stress imposed by contracting PTFE, and voids take up expanding material. Increases dielectric constant, while voids reduce it.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Selamat, Mohd Zulkefli, E-mail: azulkeflis@utem.edu.my; Yusuf, Muhammad Yusri Md, E-mail: yusri.cheras@gmail.com; Wer, Tio Kok, E-mail: to91@hotmail.my

Bipolar plates are key components in Proton Exchange Membrane (PEM) fuel cells. They carry current away from the cell and withstand the clamping force of the stack assembly. Therefore, PEM fuel cell bipolar plates must have high electrical conductivity and adequate mechanical strength, in addition to being light weight and low cost in terms of both applicable materials and production methods. In this research, the raw materials used to fabricate the high performance bipolar plate are Graphite (Gr), Stannum (Sn) and Polypropylene (PP). All materials used was in powder form and Gr and Sn act as fillers and the PPmore » acts as binder. The ratio of fillers (Gr/Sn) and binder (PP) was fixed at 80:20. For the multi-conductive filler, small amount of Sn, which is 10 up to 20wt% (from the total weight of fillers 80%) have been added into Gr/Sn/PP composite. The fillers were mixed by using the ball mill machine. The second stage of mixing process between the mixer of fillers and binder is also carried out by using ball mill machine before the compaction process by the hot press machine. The effect of formation temperatures (160°C-170°C) on the properties of Gr/Sn/PP composite had been studied in detail, especially the electrical conductivity, bulk density, hardness and microstructure analysis of Gr/Sn/PP composite. The result shows that there are significant improvement in the electrical conductivity and bulk density, which are exceeding the US-DoE target with the maximum value of 265.35 S/cm and 1.682g/cm{sup 3} respectively.« less

Mechanical properties of three layer glass fibre reinforced unsaturated polyester filled with P84 Polyimide

NASA Astrophysics Data System (ADS)

Ibrahim, Nik Noor Idayu Nik; Mamauod, Siti Nur Liyana; Romli, Ahmad Zafir

2017-12-01

The glass fibre reinforced orthophthalic unsaturated polyester composite was widely used in the pipeline industry as a replacement to the corroded steel pipes. A filler which possesses high mechanical performance at high temperature; P84 Polyimide used as the particulate reinforcement in the unsaturated polyester matrix system to increase the mechanical performance of the glass fibre reinforced unsaturated polyester. The glass fibre composite laminates were prepared through a hand lay-up technique and fabricated into three layer laminate. Prior to be used as the matrix system in the lamination process, the unsaturated polyester resin was mixed with masterbatch P84 Polyimide at three loadings amount of 1, 3, and 5 wt%. The addition of P84 Polyimide at 1, 3, and 5 wt% increased the tensile properties and flexural properties especially at 1 wt% filler loading. As the filler loading increased, the tensile properties and flexural properties showed decreasing pattern. In the dynamic mechanical analysis, the values of storage modulus were taken at two points; 50 °C and 150 °C which were the storage modulus before and after the glass transition temperature. All storage modulus showed fluctuation trend for both before and after Tg. However, the storage modulus of the filled composite laminates after Tg showed higher values than unfilled composite laminates at all filler loading. Since the P84 Polyimide possesses high thermal stability, the presence of P84 Polyimide inside the composite system had assisted in delaying the Tg. In terms of the filler dispersion, the Cole-Cole plot showed an imperfect semi-circular shape which indicated good filler dispersion.

Morphology, mechanical and thermal oxidative aging properties of HDPE composites reinforced by nonmetals recycled from waste printed circuit boards.

PubMed

Yang, Shuangqiao; Bai, Shibing; Wang, Qi

2016-11-01

In this study nonmetals recycled from waste printed circuit boards (NPCB) is used as reinforce fillers in high-density polyethylene (HDPE) composites. The morphology, mechanical and thermal oxidative aging properties of NPCB reinforced HDPE composites are assessed and it compared with two other commercial functional filler for the first time. Mechanical test results showed that NPCB could be used as reinforcing fillers in the HDPE composites and mechanical properties especially for stiffness is better than other two commercial fillers. The improved mechanical property was confirmed by the higher aspect ratio and strong interfacial adhesion in scanning electron microscopy (SEM) studies. The heat deflection temperature (HDT) test showed the presence of fiberglass in NPCB can improve the heat resistance of composite for their potential applications. Meanwhile, the oxidation induction time (OIT) and the Fourier transform infrared (FTIR) spectroscopy results showed that NPCB has a near resistance to oxidation as two other commercial fillers used in this paper. The above results show the reuse of NPCB in the HDPE composites represents a promising way for resolving both the environmental pollution and the high-value reuse of resources. Copyright © 2015. Published by Elsevier Ltd.

Improving Dispersion and Barrier Properties of Polyketone/Graphene Nanoplatelet Composites via Noncovalent Functionalization Using Aminopyrene.

PubMed

Cho, Jaehyun; Jeon, Ikseong; Kim, Seong Yun; Lim, Soonho; Jho, Jae Young

2017-08-23

A series of polyketone (PK) nanocomposite films with varying content of noncovalently functionalized graphene nanoplatelet with 1-aminopyrene (GNP/APy) is prepared by solution blending with a solvent of hexafluoro-2-propanol. GNP/APy, prepared by a facile method, can effectively induce specific interaction such as hydrogen bonding between the amine functional group of GNP/APy and the carbonyl functional group of the PK matrix. With comparison of GNP and GNP/Py as reference materials, intensive investigation on filler-matrix interaction is achieved. In addition, the dispersion state of the functionalized GNP (f-GNPs; GNP/Py and GNP/APy) in the PK matrix is analyzed by three-dimensional nondestructive X-ray microcomputed tomography, and the increased dispersion state of those fillers results in significant improvement in the water vapor transmission rate (WVTR). The enhancement in WVTR of the PK/GNP/APy nanocomposite film at 1 wt % loading of filler leads to a barrier performance approximately 2 times larger compared to that of PK/GNP nanocomposite film and an approximately 92% reduction in WVTR compared to the case of pristine PK film. We expect that this facile method of graphene functionalization to enhance graphene dispersibility as well as interfacial interaction with the polymer matrix will be widely utilized to expand the potential of graphene materials to barrier film applications.

Squid pen-inspired chitinous functional materials: Hierarchical chitin fibers by centrifugal jet-spinning and transparent chitin fiber-reinforced composite

NASA Astrophysics Data System (ADS)

Jeong, Seung-Hwan; Kim, Joong-Kwon; Lim, Young-Woo; Hwang, Hyun-Bin; Kwon, Hee-Young; Bae, Byeong-Soo; Jin, Jungho

2018-01-01

Here, inspired by the fibrous composite structure of a squid pen, we introduce hierarchical chitin fibers (herein, termed "Chiber") and their transparent composites and demonstrate the potential of these chitinous functional materials as a sustainable separation-membrane and reinforcing filler for composites. We employ a centrifugal jet-spinning process to fabricate Chiber with aligned chitin nanofibrillar architectures, for which we discuss the processing-morphology relationship. A nonwoven fiber-mat made of Chiber exhibits excellent adsorbing performance for a toxic ionic dye (Congo Red), and has a low coefficient of thermal expansion comparable to that of glass fibers. Finally, we demonstrate a squid pen-mimetic transparent composite using Chiber and investigate its optical property.

Understanding the Reliability of Solder Joints Used in Advanced Structural and Electronics Applications: Part 2 - Reliability Performance.

DOE PAGES

Vianco, Paul T.

2017-03-01

Whether structural or electronic, all solder joints must provide the necessary level of reliability for the application. The Part 1 report examined the effects of filler metal properties and the soldering process on joint reliability. Filler metal solderability and mechanical properties, as well as the extents of base material dissolution and interface reaction that occur during the soldering process, were shown to affect reliability performance. The continuation of this discussion is presented in this Part 2 report, which highlights those factors that directly affect solder joint reliability. There is the growth of an intermetallic compound (IMC) reaction layer at themore » solder/base material interface by means of solid-state diffusion processes. In terms of mechanical response by the solder joint, fatigue remains as the foremost concern for long-term performance. Thermal mechanical fatigue (TMF), a form of low-cycle fatigue (LCF), occurs when temperature cycling is combined with mismatched values of the coefficient of thermal expansion (CTE) between materials comprising the solder joint “system.” Vibration environments give rise to high-cycle fatigue (HCF) degradation. Although accelerated aging studies provide valuable empirical data, too many variants of filler metals, base materials, joint geometries, and service environments are forcing design engineers to embrace computational modeling to predict the long-term reliability of solder joints.« less

Quantitative Electron Tomography of Rubber Composites

NASA Astrophysics Data System (ADS)

Staniewicz, Lech; Vaudey, Thomas; Degrandcourt, Christophe; Couty, Marc; Gaboriaud, Fabien; Midgley, Paul

2014-06-01

Rubber composite materials have many applications, one example being tyre manufacture. The presence of a filler material in the composite (such as carbon black or silica) causes its mechanical properties to differ in several ways when compared to pure rubber such as viscoelastic behaviour (the Payne effect), increased tensile strength and improved wear resistance. To fully understand these properties, it is necessary to characterise how the filler material is organised on the nanoscale. Using composite materials representative of those found in tyres, this work illustrates the use of electron tomography and machine learning methods as tools to describe the percolation behaviour of the filler; in this case, we focus on the largest proportion of particles absorbed into one single object as a function of particle spacing.

Synthesis and characterization of biopolymer based mixed matrix membranes for pervaporative dehydration.

PubMed

Das, Paramita; Ray, Samit Kumar

2014-03-15

Several blend membranes were prepared from different weight ratios of polyvinyl alcohol (PVA) and hydroxyethyl cellulose (HEC) and these unfilled membranes were crosslinked with maleic acid. In a similar way mixed matrix blend membranes were also prepared by varying weight ratio of PVA and HEC with micro and nano bentonite filler in each of these blends. These membranes were used for pervaporative dehydration of 89 wt% tetrahydrofuran (THF). Three membranes designated as UF (unfilled), MF2 (containing 2 wt% micro filler) and NF2 (containing 2 wt% nano filler) showing the best results for flux and selectivity were identified. These membranes were characterized by FTIR, UV, XRD and DTA-TG and used for separation of 80-99 wt% THF from water by pervaporation. The NF2 membrane was found to show the best results in terms of flux and separation factor. Copyright © 2013 Elsevier Ltd. All rights reserved.

Morphologies, Processing and Properties of Ceramic Foams from Pre-Ceramic Foams from Pre-Ceramic Polymer Routes

NASA Technical Reports Server (NTRS)

Stackpoole, Mairead; Simoes, Conan R.; Venkatapathy, Ethiras (Technical Monitor)

2002-01-01

The current research is focused on processing ceramic foams that have potential as a thermal protection material. Ceramic foams with different architectures were formed from the pyrolysis of pre-ceramic polymers at 1200 C in different atmospheres. In some systems a sacrificial polyurethane was used as the blowing agent. We have also processed foams using sacrificial fillers to introduce controlled cell sizes. Each sacrificial filler or blowing agent leads to a unique morphology. The effect of different fillers on foam morphologies will be presented. The presentation will also focus on characterization of these foams in terms of mechanical and thermal properties. Foams processed using these approaches having bulk densities ranging from 0.15 to 0.9 g per cubic centimeter and a cell sizes from 5 to 500 micrometers. Compression strengths ranged from 2 to 7 MPa for these materials.

Control of polymerization shrinkage and stress in nanogel-modified monomer and composite materials

PubMed Central

Moraes, Rafael R.; Garcia, Jeffrey W.; Barros, Matthew D.; Lewis, Steven H.; Pfeifer, Carmem S.; Liu, JianCheng; Stansbury, Jeffrey W.

2011-01-01

Objectives This study demonstrates the effects of nano-scale prepolymer particles as additives to model dental monomer and composite formulations. Methods Discrete nanogel particles were prepared by solution photopolymerization of isobornyl methacrylate and urethane dimethacrylate in the presence of a chain transfer agent, which also provided a means to attach reactive groups to the prepolymer. Nanogel was added to triethylene glycol dimethacrylate (TEGDMA) in increments between 5 and 40 wt% with resin viscosity, reaction kinetics, shrinkage, mechanical properties, stress and optical properties evaluated. Maximum loading of barium glass filler was determined as a function of nanogel content and composites with varied nanogel content but uniform filler loading were compared in terms of consistency, conversion, shrinkage and mechanical properties. Results High conversion, high molecular weight internally crosslinked and cyclized nanogel prepolymer was efficiently prepared and redispersed into TEGDMA with an exponential rise in viscosity accompanying nanogel content. Nanogel addition at any level produced no deleterious effects on reaction kinetics, conversion or mechanical properties, as long as reactive nanogels were used. A reduction in polymerization shrinkage and stress was achieved in proportion to nanogel content. Even at high nanogel concentrations, the maximum loading of glass filler was only marginally reduced relative to the control and high strength composite materials with low shrinkage were obtained. Significance The use of reactive nanogels offers a versatile platform from which resin and composite handling properties can be adjusted while the polymerization shrinkage and stress development that challenge the adhesive bonding of dental restoratives are controllably reduced. PMID:21388669

Control of polymerization shrinkage and stress in nanogel-modified monomer and composite materials.

PubMed

Moraes, Rafael R; Garcia, Jeffrey W; Barros, Matthew D; Lewis, Steven H; Pfeifer, Carmem S; Liu, JianCheng; Stansbury, Jeffrey W

2011-06-01

This study demonstrates the effects of nano-scale prepolymer particles as additives to model dental monomer and composite formulations. Discrete nanogel particles were prepared by solution photopolymerization of isobornyl methacrylate and urethane dimethacrylate in the presence of a chain transfer agent, which also provided a means to attach reactive groups to the prepolymer. Nanogel was added to triethylene glycol dimethacrylate (TEGDMA) in increments between 5 and 40 wt% with resin viscosity, reaction kinetics, shrinkage, mechanical properties, stress and optical properties evaluated. Maximum loading of barium glass filler was determined as a function of nanogel content and composites with varied nanogel content but uniform filler loading were compared in terms of consistency, conversion, shrinkage and mechanical properties. High conversion, high molecular weight internally crosslinked and cyclized nanogel prepolymer was efficiently prepared and redispersed into TEGDMA with an exponential rise in viscosity accompanying nanogel content. Nanogel addition at any level produced no deleterious effects on reaction kinetics, conversion or mechanical properties, as long as reactive nanogels were used. A reduction in polymerization shrinkage and stress was achieved in proportion to nanogel content. Even at high nanogel concentrations, the maximum loading of glass filler was only marginally reduced relative to the control and high strength composite materials with low shrinkage were obtained. The use of reactive nanogels offers a versatile platform from which resin and composite handling properties can be adjusted while the polymerization shrinkage and stress development that challenge the adhesive bonding of dental restoratives are controllably reduced. Copyright © 2011 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Effect of formation temperature on properties of graphite/stannum composite for bipolar plate

NASA Astrophysics Data System (ADS)

Selamat, Mohd Zulkefli; Yusuf, Muhammad Yusri Md; Wer, Tio Kok; Sahadan, Siti Norbaya; Malingam, Sivakumar Dhar; Mohamad, Noraiham

2016-03-01

Bipolar plates are key components in Proton Exchange Membrane (PEM) fuel cells. They carry current away from the cell and withstand the clamping force of the stack assembly. Therefore, PEM fuel cell bipolar plates must have high electrical conductivity and adequate mechanical strength, in addition to being light weight and low cost in terms of both applicable materials and production methods. In this research, the raw materials used to fabricate the high performance bipolar plate are Graphite (Gr), Stannum (Sn) and Polypropylene (PP). All materials used was in powder form and Gr and Sn act as fillers and the PP acts as binder. The ratio of fillers (Gr/Sn) and binder (PP) was fixed at 80:20. For the multi-conductive filler, small amount of Sn, which is 10 up to 20wt% (from the total weight of fillers 80%) have been added into Gr/Sn/PP composite. The fillers were mixed by using the ball mill machine. The second stage of mixing process between the mixer of fillers and binder is also carried out by using ball mill machine before the compaction process by the hot press machine. The effect of formation temperatures (160°C-170°C) on the properties of Gr/Sn/PP composite had been studied in detail, especially the electrical conductivity, bulk density, hardness and microstructure analysis of Gr/Sn/PP composite. The result shows that there are significant improvement in the electrical conductivity and bulk density, which are exceeding the US-DoE target with the maximum value of 265.35 S/cm and 1.682g/cm3 respectively.

A comparative study of green composites based on tapioca starch and celluloses

NASA Astrophysics Data System (ADS)

Owi, Wei Tieng; Lin, Ong Hui; Sam, Sung Ting; Mern, Chin Kwok; Villagracia, Al Rey; Santos, Gil Nonato C.; Akil, Hazizan Md

2017-07-01

The objective of this study was to compare the properties of green composites based on tapioca starch (TS) and celluloses isolated from empty fruit bunches (EFB) and commercial celluloses from cotton linter (supplied by Sigma). Empty fruit bunches (EFB) acted as the main source to obtain the cellulose by using a chemical approach whereas the commercial cellulose from Sigma was used as reference. The TS/cellulose composite films were prepared using cellulose in varying proportions as filler into TS matrix by a casting method. The amount of celluloses added into the tapioca starch were 5, 10, 15, 20 and 25 phr (as per dry mass of TS). The celluloses were characterized using Fourier transform infrared (FTTR) spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). While the green composite films were analyzed in terms of thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), SEM and tensile properties. FTTR analysis confirmed the removal of non-cellulosic materials such as hemicelluloses and lignin from raw EFB after the chemical treatment. XRD diffractograms revealed that the crystallinity of celluloses EFB increased from 43.1 % of raw EFB to 52.1 %. SEM images showed the fibrillar structure of cellulose isolated from EFB. The TGA and derivative thermogravimetric (DTG) curves of green composite films showed no significant effect on the thermal stability. Melting temperature of TS/cellulose EFB higher than neat TS while TS/cellulose Sigma lower than neat TS. The green composite films with 15 phr cellulose from EFB filler loading provided the best tensile properties in term of its strength and modulus. However, in term of elongation at break, the percentage elongation decreased with the increased of the amount of filler loading. SEM images of the films demonstrated a good interaction between cellulose filler and TS matrix especially with the addition of 15 phr of cellulose from EFB.

Complex refractive index of starch acetate used as a biodegradable pigment and filler of paper

NASA Astrophysics Data System (ADS)

Karvinen, Petri; Oksman, Antti; Silvennoinen, Raimo; Mikkonen, Hannu

2007-05-01

Complex refractive index of strongly depolarizing starch acetate is investigated as a function of bulk package density, which is compulsory parameter in analysis of light scattering from nanoscale starch acetate pigments and fillers. The measurements were made using a laser-goniometer and spectrophotometer to gain data for refractive index analysis according to the Brewster's law and Fresnel equations. The real part of refractive index was verified by microscopic immersion method.

Quantification of cell response to polymeric composites using a two-dimensional gradient platform.

PubMed

Lin, Nancy J; Hu, Haiqing; Sung, Lipin; Lin-Gibson, Sheng

2009-07-01

A simple and straightforward screening process to assess the toxicity and corresponding cell response of dental composites would be useful prior to extensive in vitro or in vivo characterization. To this end, gradient composite samples were prepared with variations in filler content/type and in degree of conversion (DC). The DC was determined using near infrared spectroscopy (NIR), and the surface morphology was evaluated by laser scanning confocal microscopy (LSCM). RAW 264.7 macrophage-like cells were cultured directly on the composite gradient samples, and cell viability, density, and area were measured at 24 h. All three measures of cell response varied as a function of material properties. For instance, compositions with higher filler content had no reduction in cell viability or cell density, even at low conversions of 52%, whereas significant decreases in viability and density were present when the filler content was 35% or below (by mass). The overall results demonstrate the complexity of the cell-material interactions, with properties including DC, filler type, filler mass ratio, and surface morphology influencing the cell response. The combinatorial approach described herein enables simultaneous screening of multiple compositions and material properties, providing a more thorough characterization of cell response for the improved selection of biocompatible composite formulations and processing conditions.

QENS investigation of filled rubbers

NASA Astrophysics Data System (ADS)

Triolo, A.; Lo Celso, F.; Negroni, F.; Arrighi, V.; Qian, H.; Lechner, R. E.; Desmedt, A.; Pieper, J.; Frick, B.; Triolo, R.

The polymer segmental dynamics is investigated in a series of silica-filled rubbers. The presence of inert fillers in polymers greatly affects the mechanical and physical performance of the final materials. For example, silica has been proposed as a reinforcing agent of elastomers in tire production. Results from quasielastic neutron scattering and Dynamic Mechanical Thermal Analysis (DMTA) measurements are presented on styrene-ran-butadiene rubber filled with silica. A clear indication is obtained of the existence of a bimodal dynamics, which can be rationalized in terms of the relaxation of bulk rubber and the much slower relaxation of the rubber adsorbed on the filler surface.

What are the necessary practice competencies for two providers: dermal fillers and botulinum toxin type A injections?

PubMed

Spear, Marcia

2010-01-01

There has been a steady increase in the number of individuals who undergo dermal fillers and botulinum toxin Type A injections. The majority of these procedures are performed by nurse providers. The purpose of this study was to collect national data on the current practice among nursing providers within the American Society of Plastic Surgical Nurses (ASPSN). The goal was to utilize the national data and develop a document of the necessary competencies to guide the practice of providers of dermal fillers and botulinum toxin Type A injections. A survey tool was developed and validated for content by expert nursing providers among the membership of the ASPSN and disseminated via e-mail to the membership of the ASPSN. In addition, data from investigator training, mentoring, and evidence from a review of the literature were also incorporated into the competency document utilizing the Competency Outcomes and Performance Assessment (COPA) model. Common core issues became apparent that included contraindications for the use of botulinum toxin Type A and dermal fillers, postprocedure complications as well as strategies in terms of managing complications. The data also revealed that there is no common method providers are taught to assess the aesthetic patient and a lack of a collaborative relationship in current practice. Overwhelmingly, the respondents supported the need for defined practice competencies. A competency document to guide the practice of providers of dermal fillers and botulinum toxin Type A has been developed for completion of this DNP project.

Electrical properties of alkali-activated slag composite with combined graphite/CNT filler

NASA Astrophysics Data System (ADS)

Rovnaník, P.; Míková, M.; Kusák, I.

2017-10-01

Alkali-activated industrial by-products such as blast furnace slag are known to possess properties which are comparable to or even better than those observed for ordinary Portland cement. The combination of alkali-activated slag matrix with conductive filler introduces new functionalities which are commonly known for self-sensing or self-heating concrete. The present paper discusses the effect of the mixture of two different conductive fillers, graphite powder and carbon nanotubes (CNTs), on the electrical properties of alkali-activated slag mortars. Prepared samples were also tested for their mechanical properties and microstructure was investigated by means of mercury intrusion porosimetry and scanning electron microscopy. The percolation threshold for the resistance was reached for the mixture containing 0.1% CNTs and 8% graphite powder.

A description of the mechanical behavior of composite solid propellants based on molecular theory

NASA Technical Reports Server (NTRS)

Landel, R. F.

1976-01-01

Both the investigation and the representation of the stress-strain response (including rupture) of gum and filled elastomers can be based on a simple functional statement. Internally consistent experiments are used to sort out the effects of time, temperature, strain and crosslink density on gum rubbers. All effects are readily correlated and shown to be essentially independent of the elastomer when considered in terms of non-dimensionalized stress, strain and time. A semiquantitative molecular theory is developed to explain this result. The introduction of fillers modifies the response, but, guided by the framework thus provided, their effects can be readily accounted for.

The effect of filler loading and morphology on the mechanical properties of contemporary composites.

PubMed

Kim, Kyo-Han; Ong, Joo L; Okuno, Osamu

2002-06-01

Little information exists regarding the filler morphology and loading of composites with respect to their effects on selected mechanical properties and fracture toughness. The objectives of this study were to: (1) classify commercial composites according to filler morphology, (2) evaluate the influence of filler morphology on filler loading, and (3) evaluate the effect of filler morphology and loading on the hardness, flexural strength, flexural modulus, and fracture toughness of contemporary composites. Field emission scanning electron microscopy/energy dispersive spectroscopy was used to classify 3 specimens from each of 14 commercial composites into 4 groups according to filler morphology. The specimens (each 5 x 2.5 x 15 mm) were derived from the fractured remnants after the fracture toughness test. Filler weight content was determined by the standard ash method, and the volume content was calculated using the weight percentage and density of the filler and matrix components. Microhardness was measured with a Vickers hardness tester, and flexural strength and modulus were measured with a universal testing machine. A 3-point bending test (ASTM E-399) was used to determine the fracture toughness of each composite. Data were compared with analysis of variance followed by Duncan's multiple range test, both at the P<.05 level of significance. The composites were classified into 4 categories according to filler morphology: prepolymerized, irregular-shaped, both prepolymerized and irregular-shaped, and round particles. Filler loading was influenced by filler morphology. Composites containing prepolymerized filler particles had the lowest filler content (25% to 51% of filler volume), whereas composites containing round particles had the highest filler content (59% to 60% of filler volume). The mechanical properties of the composites were related to their filler content. Composites with the highest filler by volume exhibited the highest flexural strength (120 to 129 MPa), flexural modulus (12 to 15 GPa), and hardness (101 to 117 VHN). Fracture toughness was also affected by filler volume, but maximum toughness was found at a threshold level of approximately 55% filler volume. Within the limitations of this study, the commercial composites tested could be classified by their filler morphology. This property influenced filler loading. Both filler morphology and filler loading influenced flexural strength, flexural modulus, hardness, and fracture toughness.

Development of a SMA-Based Slat-Cove Filler for Reduction of Aeroacoustic Noise Associated With Transport-Class Aircraft Wings

NASA Technical Reports Server (NTRS)

Turner, Travis L.; Kidd, Reggie T.; Hartl, Darren J.; Scholten, William D.

2013-01-01

Airframe noise is a significant part of the overall noise produced by typical, transport-class aircraft during the approach and landing phases of flight. Leading-edge slat noise is a prominent source of airframe noise. The concept of a slat-cove filler was proposed in previous work as an effective means of mitigating slat noise. Bench-top models were deployed at 75% scale to study the feasibility of producing a functioning slat-cove filler. Initial results from several concepts led to a more-focused effort investigating a deformable structure based upon pseudoelastic SMA materials. The structure stows in the cavity between the slat and main wing during cruise and deploys simultaneously with the slat to guide the aerodynamic flow suitably for low noise. A qualitative parametric study of SMA-enabled, slat-cove filler designs was performed on the bench-top. Computational models were developed and analyses were performed to assess the displacement response under representative aerodynamic load. The bench-top and computational results provide significant insight into design trades and an optimal design.

Effective thermal conductivity of isotropic polymer composites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tavman, I.H.

1998-07-01

The effective thermal conductivity of tin powder filled high density polyethylene composites is investigated experimentally as a function of filler concentration and the measured values are compared with the existing theoretical and empirical models. Samples are prepared by compression molding process, up to 16% volumetric concentration of tin particles. The thermal conductivity is measured by a modified hot wire technique in a temperature range from about 0 to 70 C. Experimental results show a region of low particle content, up to about 10% volume concentration, where the increase in thermal conductivity is rather slow. The filler particles are dispersed inmore » the matrix material in this region, the thermal conductivity is best predicted by Maxwell`s model and Nielsen`s model with A = 1.5, {phi}{sub m} = 0.637. Whereas, at high filler concentrations, the filler particles tend to form agglomerates and conductive chains in the direction of heat flow resulting in a rapid increase in thermal conductivity. A model developed by Agari and Uno estimates the thermal conductivity in this region, using two experimentally determined constants.« less

Supramolecular Polymer Nanocomposites - Improvement of Mechanical Properties

NASA Astrophysics Data System (ADS)

Hinricher, Jesse; Neikirk, Colin; Priestley, Rodney

2015-03-01

Supramolecular polymers differ from traditional polymers in that their repeat units are connected by hydrogen bonds that can reversibly break and form under various stimuli. They can be more easily recycled than conventional materials, and their highly temperature dependent viscosities result in reduced energy consumption and processing costs. Furthermore, judicious selection of supramolecular polymer architecture and functionality allows the design of advanced materials including shape memory and self-healing materials. Supramolecular polymers have yet to see widespread use because they can't support much weight due to their inherent mechanical weakness. In order to address this issue, the mechanical strength of supramolecular polymer nanocomposites based on ureidopyrmidinone (UPy) telechelic poly(caprolactone) doped with surface activated silica nanoparticles was investigated by tensile testing and dynamic mechanical analysis. The effects of varying amounts and types of nanofiller surface functionality were investigated to glean insight into the contributions of filler-filler and filler-matrix interactions to mechanical reinforcement in supramolecular polymer nanocomposites. MRSEC NSF DMR 0819860 (PI: Prof. N. Phuan Ong) REU Site Grant: NSF DMR-1156422 (PI: Prof. Mikko Haataja)

High permittivity induced by interaction between PI matrix and graphite oxide filler

NASA Astrophysics Data System (ADS)

Lai, Maobai; Kou, Siwang; Yu, Shuhui; Sun, Rong; Wong, Ching-Ping

2014-09-01

Functionalized graphite oxide was introduced to polyimide and a colossal permittivity was obtained in the derived GO/PI composites. At 1 kHz, the permittivity of the composite with 3 wt% GO loading was up to 7179. In comparison, the permittivities of rGO/PI with 3 wt% rGO loading and GO/ER with 3 wt% GO loading were only 14.41 and 26.64, respectively. By analyzing the molecular structure and chemical bonding of GO/PI composites, we proposed that interaction occurred between the GO fillers carrying functional groups and the PI matrix with a conjugate system, which accounts for the high permittivity of GO/PI composites.

The heterogeneity of segmental dynamics of filled EPDM by (1)H transverse relaxation NMR.

PubMed

Moldovan, D; Fechete, R; Demco, D E; Culea, E; Blümich, B; Herrmann, V; Heinz, M

2011-01-01

Residual second moment of dipolar interactions M(2) and correlation time segmental dynamics distributions were measured by Hahn-echo decays in combination with inverse Laplace transform for a series of unfilled and filled EPDM samples as functions of carbon-black N683 filler content. The fillers-polymer chain interactions which dramatically restrict the mobility of bound rubber modify the dynamics of mobile chains. These changes depend on the filler content and can be evaluated from distributions of M(2). A dipolar filter was applied to eliminate the contribution of bound rubber. In the first approach the Hahn-echo decays were fitted with a theoretical relationship to obtain the average values of the (1)H residual second moment and correlation time <τ(c)>. For the mobile EPDM segments the power-law distribution of correlation function was compared to the exponential correlation function and found inadequate in the long-time regime. In the second approach a log-Gauss distribution for the correlation time was assumed. Furthermore, using an averaged value of the correlation time, the distributions of the residual second moment were determined using an inverse Laplace transform for the entire series of measured samples. The unfilled EPDM sample shows a bimodal distribution of residual second moments, which can be associated to the mobile polymer sub-chains (M(2) ≅ 6.1 rad (2) s(-2)) and the second one associated to the dangling chains M(2) ≅ 5.4 rad(2) s(-2)). By restraining the mobility of bound rubber, the carbon-black fillers induce diversity in the segmental dynamics like the apparition of a distinct mobile component and changes in the distribution of mobile and free-end polymer segments. Copyright © 2010 Elsevier Inc. All rights reserved.

The heterogeneity of segmental dynamics of filled EPDM by 1H transverse relaxation NMR

NASA Astrophysics Data System (ADS)

Moldovan, D.; Fechete, R.; Demco, D. E.; Culea, E.; Blümich, B.; Herrmann, V.; Heinz, M.

2011-01-01

Residual second moment of dipolar interactions M∼2 and correlation time segmental dynamics distributions were measured by Hahn-echo decays in combination with inverse Laplace transform for a series of unfilled and filled EPDM samples as functions of carbon-black N683 filler content. The fillers-polymer chain interactions which dramatically restrict the mobility of bound rubber modify the dynamics of mobile chains. These changes depend on the filler content and can be evaluated from distributions of M∼2. A dipolar filter was applied to eliminate the contribution of bound rubber. In the first approach the Hahn-echo decays were fitted with a theoretical relationship to obtain the average values of the 1H residual second moment and correlation time <τc>. For the mobile EPDM segments the power-law distribution of correlation function was compared to the exponential correlation function and found inadequate in the long-time regime. In the second approach a log-Gauss distribution for the correlation time was assumed. Furthermore, using an averaged value of the correlation time, the distributions of the residual second moment were determined using an inverse Laplace transform for the entire series of measured samples. The unfilled EPDM sample shows a bimodal distribution of residual second moments, which can be associated to the mobile polymer sub-chains (M∼2≅6.1 rad s) and the second one associated to the dangling chains M∼2≅5.4 rad s). By restraining the mobility of bound rubber, the carbon-black fillers induce diversity in the segmental dynamics like the apparition of a distinct mobile component and changes in the distribution of mobile and free-end polymer segments.

Thermal Conductivity of Ultem(TradeMark)/Carbon Nanofiller Blends

NASA Technical Reports Server (NTRS)

Ghose, S.; Watson, K. A.; Delozier, D. M.; Working, D. C.; Connell, J. W.; Smith, J. G., Jr.; Sun, Y. P.; Lin, Y.

2006-01-01

In an effort to improve polymer thermal conductivity (TC), Ultem(TradeMark) 1000 was compounded with nano-fillers of carbon allotropes. Ultem(TradeMark) 1000 was selected since it is both solution and melt processable. As-received and modified multiwalled carbon nanotubes (MWCNTs), vapor grown carbon nanofibers (CNF) and expanded graphite (EG) were investigated. MWCNTs were modified by functionalizing the surface through oxidization with concentrated acids, mixing with an alkyl bromide, and addition of alkyl and phosphorus compounds after initial treatment with n-butyl lithium. Functionalization was performed to improve the TC compatibility between the resin and MWCNTs. It was postulated that this may provide an improved interface between the MWCNT and the polymer which would result in enhanced TC. The nano-fillers were mixed with Ultem(TradeMark) 1000 in the melt and in solution at concentrations ranging from 5 to 40 wt%. Ribbons were extruded from the blends to form samples where the nano-fillers were aligned to some degree in the extrusion direction. Samples were also fabricated by compression molding resulting in random orientation of the nano-fillers. Thermal properties of the samples were evaluated by Differential Scanning Calorimetry (DSC) and Thermal Gravimetric Analyzer (TGA). Tensile properties of aligned samples were determined at room temperature. The specimens were cut from the ribbons in the extrusion direction; hence the nano-fillers are somewhat aligned in the direction of stress. Typically it was observed that melt mixed samples exhibited superior mechanical properties compared to solution mixed samples. As expected, increased filler loading led to increased modulus and decreased elongation with respect to the neat polymer. The degree of dispersion and alignment of the nano-fillers was determined by high-resolution scanning electron microscopy (HRSEM). HRSEM of the ribbons revealed that the MWCNTs and CNFs were predominantly aligned in the flow direction. The TC of the samples was measured using a Nanoflash(TradeMark) instrument. Since the MWCNTs and CNF are anisotropic, the TC was expected to be different in the longitudinal (parallel to the nanotube and fiber axis) and transverse (perpendicular to the nanotube and fiber axis) directions. The extruded ribbons provided samples for transverse TC measurements. However, to determine the TC in the longitudinal direction, the ribbons needed to be stacked and molded under 1.7 MPa and 270 C. Samples were then obtained by cutting the molded block with a diamond saw. The largest TC improvement was achieved for aligned samples when the measurement was performed in the direction of MWCNT and CNF alignment (i.e. longitudinal axis). Unaligned samples also showed a significant improvement in TC and may be potentially useful in applications when it is not possible to align the nano-filler. The results of this study will be presented.

Characteristic Asphalt Concrete Wearing Course (ACWC) Using Variation Lime Filler

NASA Astrophysics Data System (ADS)

Permana, R. A.; Pramesti, F. P.; Setyawan, A.

2018-03-01

This research use of lime filler Sukaraja expected add durability layers of concrete pavement is asphalt damage caused by the weather and load traffic. This study attempts to know how much value characteristic Marshall on a mixture of concrete asphalt using lime filler. This research uses experimental methods that is with a pilot to get results, thus will look filler utilization lime on construction concrete asphalt variation in filler levels 2 %, 3 %, 4 %.The results showed that the use of lime filler will affect characteristic a mixture of concrete asphalt. The more filler chalk used to increase the value of stability. On the cretaceous filler 2 % value of stability is 1067,04 kg. When lime filler levels added to the levels of filler 4 %, the value of stability increased to 1213,92 kg. The flexibility increased the number of filler as levels lime 2 % to 4 % suggests that are conducted more stiff mix.

Thermal and Mechanical Characteristics of Polymer Composites Based on Epoxy Resin, Aluminium Nanopowders and Boric Acid

NASA Astrophysics Data System (ADS)

Nazarenko, O. B.; Melnikova, T. V.; Visakh, P. M.

2016-01-01

The epoxy polymers are characterized by low thermal stability and high flammability. Nanoparticles are considered to be effective fillers of polymer composites for improving their thermal and functional properties. In this work, the epoxy composites were prepared using epoxy resin ED-20, polyethylene polyamine as a hardener, aluminum nanopowder and boric acid fine powder as flame-retardant filler. The thermal characteristics of the obtained samples were studied using thermogravimetric analysis and differential scanning calorimetry. The mechanical characteristics of epoxy composites were also studied. It was found that an addition of all fillers enhances the thermal stability and mechanical characteristics of the epoxy composites. The best thermal stability showed the epoxy composite filled with boric acid. The highest flexural properties showed the epoxy composite based on the combination of boric acid and aluminum nanopowder.

Controlled High Filler Loading of Functionalized Al2O3-Filled Epoxy Composites for LED Thermal Management

NASA Astrophysics Data System (ADS)

Permal, Anithambigai; Devarajan, Mutharasu; Hung, Huong Ling; Zahner, Thomas; Lacey, David; Ibrahim, Kamarulazizi

2018-03-01

Thermal management in light-emitting diode (LED) has been extensively researched recently. This study is intended to develop an effective thermally conductive epoxy composite as thermal interface material (TIM) for headlamp LEDs. Silane-functionalized aluminum oxide (Al2O3) powder of different average particle sizes (44 and 10 µm) was studied for its feasibility as filler at its maximum loading. A detailed comparison of three different methods of particle dispersions, hand-mix, speed-mix and calendaring process (3-roll mill), has been reported. The dispersion of Al2O3 particles, the thermal conductivity and thermal degradation characteristics of the composites were investigated and explained in detail. At 75 wt.% filler loading, 10 and 44 µm Al2O3 achieved composite thermal conductivities of 1.13 and 2.08 W/mK, respectively, which is approximately 528 and 1055% of enhancement with respect to neat epoxy. The package-level thermal performance of the LED employing the Al2O3-filled TIMs was carried out using thermal transient analysis. The experimental junction-to-ambient thermal resistances ( R thJ-A) achieved were 6.65, 7.24, and 8.63 K/W for Al2O3_44µm, Al2O3_10µm and neat epoxy, respectively. The results revealed that the Al2O3_44µm fillers-filled composite performed better in both material-level and package-level thermal characteristics.

Caries-preventive effect of fissure sealant containing surface reaction-type pre-reacted glass ionomer filler and bonded by self-etching primer.

PubMed

Shimazu, Kisaki; Ogata, Kiyokazu; Karibe, Hiroyuki

2012-01-01

We aimed to evaluate the caries-preventive effect of a fissure sealant containing surface reaction-type pre-reacted glass ionomer (S-PRG) filler and bonded by self-etching primer versus those of 2 conventional resin-based sealants bonded by acid etching in terms of its impact on enamel demineralization and remineralization, enamel bond strength, and integrity of debonded enamel surfaces. Demineralization, remineralization, and bond strength on untreated enamel and enamel subsurface lesions of bovine incisors were assessed among the sealants by polarizing microscopy and microradiography; debonded enamel surfaces were examined by scanning electron microscopy. The conventional resin-based sealants bonded by acid etching caused surface defects on the enamel subsurface lesions and significantly increased the lesion depth (p = 0.014), indicative of enamel demineralization. However the S-PRG filler-containing sealant bonded by self-etching primer maintained the enamel surface integrity and inhibited enamel demineralization. No difference in bond strength on both untreated enamel and enamel subsurface lesions was noted among the sealants. An S-PRG filler-containing fissure sealant bonded by self-etching primer can prevent enamel demineralization, microleakage, and gaps without the tags created by acid etching regardless of the enamel condition. Such sealants are suitable for protecting the pits and fissures of immature permanent teeth.

Fracture resistant, antibiofilm adherent, self-assembled PMMA/ZnO nanoformulations for biomedical applications: physico-chemical and biological perspectives of nano reinforcement.

PubMed

Raj, Indu; Mozetic, Miran; Jayachandran, V P; Jose, Jiya; Thomas, Sabu; Kalarikkal, Nandakumar

2018-07-27

Antimicrobial, antibiofilm adherent, fracture resistant nano zinc oxide (ZnO NP) formulations based on poly methyl methacrylate (PMMA) matrix were developed using a facile ex situ compression moulding technique. These formulations demonstrated potent, long-term biofilm-resisting effects against Candida albicans (9000 CFU to 1000 CFU) and Streptococcus mutans. Proposed mechanism of biofilm resistance was the release of metallic ions/metal oxide by 'particle-corrosion'. MTT and cellular proliferation assays confirmed both qualitatively and quantitatively equal human skin fibroblast cell line proliferations (approximately 75%) on both PMMA/ZnO formulation and neat PMMA. Mechanical performance was evaluated over a range of filler loading, and theoretical models derived from Einstein, Guth, Thomas and Quemade were chosen to predict the modulus of the nanoformulations. All the models gave better fitting at lower filler content, which could be due to restricted mobility of the polymer chains by the constrained zone/interfacial rigid amorphous zone and also due to stress absorption by the highly energized NPs. Fracture mechanics were clearly described based on substantial experimental evidence surrounding crack prevention in the initial zones of fracture. Filler-polymer interactions at the morphological and structural levels were elucidated through FTIR, XRD, SEM, TEM and AFM analyses. Major clinical challenges in cancer patient rehabilitation and routine denture therapy are frequent breakage of the prostheses and microbial colonization on the prostheses/tissues. In the present study, we succeeded in developing an antimicrobial, mechanically improved fracture resistant, biocompatible nanoformulation in a facile manner without the bio-toxic effects of surface modifiers/functionalization. This PMMA/ZnO nanoformulation could serve as a cost effective breakthrough biomaterial in the field of prosthetic rehabilitation and local drug delivery scaffolds for abused tissues.

Preventing the Complications Associated with the Use of Dermal Fillers in Facial Aesthetic Procedures: An Expert Group Consensus Report.

PubMed

Urdiales-Gálvez, Fernando; Delgado, Nuria Escoda; Figueiredo, Vitor; Lajo-Plaza, José V; Mira, Mar; Ortíz-Martí, Francisco; Del Rio-Reyes, Rosa; Romero-Álvarez, Nazaret; Del Cueto, Sofía Ruiz; Segurado, María A; Rebenaque, Cristina Villanueva

2017-06-01

The use of dermal fillers in minimally invasive facial aesthetic procedures has become increasingly popular of late, yet as the indications and the number of procedures performed increase, the number of complications is also likely to increase. Paying special attention to specific patient characteristics and to the technique used can do much to avoid these complications. Indeed, a well-trained physician can also minimize the impact of such problems when they do occur. A multidisciplinary group of experts in aesthetic treatments reviewed the main factors associated with the complications that arise when using dermal fillers. A search of English, French and Spanish language articles in PubMed was performed using the terms "complications" OR "soft filler complications" OR "injectable complications" AND "dermal fillers". An initial document was drafted that reflected the complications identified and recommendations as to how they should be handled. This document was then reviewed and modified by the expert panel, until a final text was agreed upon and validated. The panel addressed consensus recommendations about the preparation, the procedure and the post-procedural care. The panel considered it crucial to obtain an accurate medical history to prevent potential complications. An additional clinical assessment, including standardized photography, is also crucial to evaluate the outcomes and prevent potential complications. Furthermore, the state of the operating theatre, the patient's health status and the preparation of the skin are critical to prevent superficial soft tissue infections. Finally, selecting the appropriate technique, based on the physician's experience, as well as the characteristics of the patient and filler, helps to ensure successful outcomes and limits the complications. This consensus document provides key elements to help clinicians who are starting to use dermal fillers to employ standard procedures and to understand how best to prevent potential complications of the treatment. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Improving the physical properties of starch using a new kind of water dispersible nano-hybrid reinforcement.

PubMed

Morales, Noé J; Candal, Roberto; Famá, Lucía; Goyanes, Silvia; Rubiolo, Gerardo H

2015-08-20

Plasticized cassava starch matrix composites reinforced by a multi-wall carbon nanotube (MWCNT)-hercynite (FeAl2O4) nanomaterial were developed. The hybrid nanomaterial consists of FeAl2O4 nanoparticles anchored strongly to the surface of the MWCNT. This nano-hybrid filler shows an irregular geometry, which provides a strong mechanical interlocking with the matrix, and excellent stability in water, ensuring a good dispersion in the starch matrix. The composite containing 0.04wt.% of the nano-hybrid filler displays increments of 370% in the Young's modulus, 138% in tensile strength and 350% in tensile toughness and a 70% decrease in water vapor permeability relative to the matrix material. All of these significant improvements are explained in terms of the nano-hybrid filler homogenous dispersion and its high affinity with both plasticizers, glycerol and water, which induces crystallization without deterioration of the tensile toughness. Copyright © 2015 Elsevier Ltd. All rights reserved.

Mechanical properties of HDPE/UHMWPE blends: effect of filler loading and filler treatment.

PubMed

Lai, K L K; Roziyanna, A; Ogunniyi, D S; Zainal, Arifin M I; Azlan, Ariffin A

2004-05-01

Various blend ratios of high-density polyethylene (HDPE) and ultra high molecular weight polyethylene (UHMWPE) were prepared with the objective of determining their suitability as biomaterials. In the unfilled state, a blend of 50/50 (HDPE/UHMWPE) ratio by weight was found to yield optimum properties in terms of processability and mechanical properties. Hydroxyapatite (HA) was compounded with the optimum blend ratio. The effects of HA loading, varied from 0 to 50wt% for both filled and unfilled blends were tested for mechanical properties. It was found that the inclusion of HA in the blend led to a remarkable improvement of mechanical properties compared to the unfilled blend. In order to improve the bonding between the polymer blend and the filler, the HA used was chemically treated with a coupling agent known as 3-(trimethoxysiyl) propyl methacrylate and the treated HA was mixed into the blend. The effect of mixing the blend with silane-treated HA also led to an overall improvement of mechanical properties.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feng, Zhili; Bunn, Jeffrey R; Tzelepis, Demetrios A

Hydrogen induced cracking (HIC) has been a persistent issue in welding of high-strength steels. Mitigating residual stresses is one of the most efficient ways to control HIC. The current study develops a proactive in-process weld residual stress mitigation technique, which manipulates the thermal expansion and contraction sequence in the weldments during welding process. When the steel weld is cooled after welding, martensitic transformation will occur at a temperature below 400 C. Volume expansion in the weld due to the martensitic transformation will reduce tensile stresses in the weld and heat affected zone and in some cases produce compressive residual stressesmore » in the weld. Based on this concept, a customized filler wire which undergoes a martensitic phase transformation during cooling was developed. The new filler wire shows significant improvement in terms of reducing the tendency of HIC in high strength steels. Bulk residual stress mapping using neutron diffraction revealed reduced tensile and compressive residual stresses in the welds made by the new filler wire.« less

Quaternary Polymer Electrolytes Containing an Ionic Liquid and a Ceramic Filler.

PubMed

Sharova, Varvara; Kim, Guk-Tae; Giffin, Guinevere A; Lex-Balducci, Alexandra; Passerini, Stefano

2016-07-01

In this work, the individual and combined effects of an ionic liquid 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide and ceramic filler silicon dioxide on the thermal and electrochemical properties of poly(ethylene oxide) electrolytes have been investigated. The electrolyte containing both components has the lowest glass transition (-60 °C) and melting temperatures (27 °C), the highest conductivity at any investigated temperature, and the highest limiting current density (at 40 °C). This solid polymer electrolyte also exhibits the best long-term cycling performance in Li/LiFePO4 cells. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Theoretical and Numerical Approaches for Determining the Reflection and Transmission Coefficients of OPEFB-PCL Composites at X-Band Frequencies

PubMed Central

Ahmad, Ahmad F.; Abbas, Zulkifly; Obaiys, Suzan J.; Ibrahim, Norazowa; Hashim, Mansor; Khaleel, Haider

2015-01-01

Bio-composites of oil palm empty fruit bunch (OPEFB) fibres and polycaprolactones (PCL) with a thickness of 1 mm were prepared and characterized. The composites produced from these materials are low in density, inexpensive, environmentally friendly, and possess good dielectric characteristics. The magnitudes of the reflection and transmission coefficients of OPEFB fibre-reinforced PCL composites with different percentages of filler were measured using a rectangular waveguide in conjunction with a microwave vector network analyzer (VNA) in the X-band frequency range. In contrast to the effective medium theory, which states that polymer-based composites with a high dielectric constant can be obtained by doping a filler with a high dielectric constant into a host material with a low dielectric constant, this paper demonstrates that the use of a low filler percentage (12.2%OPEFB) and a high matrix percentage (87.8%PCL) provides excellent results for the dielectric constant and loss factor, whereas 63.8% filler material with 36.2% host material results in lower values for both the dielectric constant and loss factor. The open-ended probe technique (OEC), connected with the Agilent vector network analyzer (VNA), is used to determine the dielectric properties of the materials under investigation. The comparative approach indicates that the mean relative error of FEM is smaller than that of NRW in terms of the corresponding S21 magnitude. The present calculation of the matrix/filler percentages endorses the exact amounts of substrate utilized in various physics applications. PMID:26474301

Tailoring of physical properties in highly filled experimental nanohybrid resin composites.

PubMed

Pick, Bárbara; Pelka, Matthias; Belli, Renan; Braga, Roberto R; Lohbauer, Ulrich

2011-07-01

To assess the elastic modulus (EM), volumetric shrinkage (VS), and polymerization shrinkage stress (PSS) of experimental highly filled nanohybrid composites as a function of matrix composition, filler distribution, and density. One regular viscosity nanohybrid composite (Grandio, VOCO, Germany) and one flowable nanohybrid composite (Grandio Flow, VOCO) were tested as references along with six highly filled experimental nanohybrid composites (four Bis-GMA-based, one UDMA-based, and one Ormocer®-based). The experimental composites varied in filler size and density. EM values were obtained from the "three-point bending" load-displacement curve. VS was calculated with Archimedes' buoyancy principle. PSS was determined in 1-mm thick specimens placed between two (poly)methyl methacrylate rods (Ø=6mm) attached to an universal testing machine. Data were analyzed using oneway ANOVA, Tukey's test (α=0.05), and linear regression analyses. The flowable composite exhibited the highest VS and PSS but lowest EM. The PSS was significantly lower with Ormocer. The EM was significantly higher among experimental composites with highest filler levels. No significant differences were found between all other experimental composites regarding VS and PSS. Filler density and size did not influence EM, VS, or PSS. Neither the filler configuration nor matrix composition in the investigated materials significantly influenced composite shrinkage and mechanical properties. The highest filled experimental composite seemed to increase EM by keeping VS and PSS low; however, matrix composition seemed to be the determinant factor for shrinkage and stress development. The Ormocer, with reduced PSS, deserves further investigation. Filler size and density did not influence the tested parameters. Copyright © 2011 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Preparation and application of nanocrystalline cellulose derived from sugarcane waste as filler modified alkanolamide on crosslink of natural rubber latex film

NASA Astrophysics Data System (ADS)

Harahap, Hamidah; Hayat, Nuim; Lubis, Marfuah

2017-07-01

Sugarcane waste is abundant sources of cellulose and it has potential to reutilize. Cellulose from sugarcane waste can be derived into nanocystalline cellulose (NCC) from crystalline region. The NCC as a filler has capability to reinforce natural rubber latex product. The crosslink in vulcanized natural rubber latex film influences several properties of product. In this work, we extracted NCC from sugarcane waste then added into natural rubber latex as filler modified alkanolamide (ALK) and also studied the crosslink of natural rubber latex films. NCC were produced from sugarcane waste by hydrolysis process with sulfuric acid 45%. The obtained NCC was characterized by using x-ray diffraction (XRD), transmission electron microscopy (TEM), and fourier transform infra red (FTIR). NCC was modified by alkanolamide and dispersed in water with filler concentration of 10%. Then the dispersion were added into latex system followed by pre-vulcanization at 70 °C. The films were prepared by coagulant dipping method and dried at 100 °C and 120 °C for 20 minutes. Characterization of NCC from sugarcane waste by using FTIR was done, it clearly showed the functional groups of cellulose. TEM showed the obtained NCC were rod-shaped with about 40-160 nm in diameter and several hundred nm in length, and XRD showed that the degree of crystalinity of NCC from sugarcane waste is 92.33%. The crosslink of natural rubber films were studied by measure the crosslink density for different filler loading by using swelling measurement with toluene solution. The result show that the crosslink density increased in line with amount of filler which added into the system, and also the crosslink density that obtained from vulcanization at 120 °C were higher than 100 °C.

Ductility dip cracking susceptibility of Inconel Filler Metal 52 and Inconel Alloy 690

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kikel, J.M.; Parker, D.M.

1998-06-01

Alloy 690 and Filler Metal 52 have become the materials of choice for commercial nuclear steam generator applications in recent years. Filler Metal 52 exhibits improved resistance to weld solidification and weld-metal liquation cracking as compared to other nickel-based filler metals. However, recently published work indicates that Filler Metal 52 is susceptible to ductility dip cracking (DDC) in highly restrained applications. Susceptibility to fusion zone DDC was evaluated using the transverse varestraint test method, while heat affected zone (HAZ) DDC susceptibility was evaluated using a newly developed spot-on-spot varestraint test method. Alloy 690 and Filler Metal 52 cracking susceptibility wasmore » compared to the DDC susceptibility of Alloy 600, Filler Metal 52, and Filler Metal 625. In addition, the effect of grain size and orientation on cracking susceptibility was also included in this study. Alloy 690, Filler Metal 82, Filler Metal 52, and Filler Metal 625 were found more susceptible to fusion zone DDC than Alloy 600. Filler Metal 52 and Alloy 690 were found more susceptible to HAZ DDC when compared to wrought Alloy 600, Filler Metal 82 and Filler Metal 625. Filler Metal 52 exhibited the greatest susceptibility to HAZ DDC of all the weld metals evaluated. The base materials were found much more resistant to HAZ DDC in the wrought condition than when autogenously welded. A smaller grain size was found to offer greater resistance to DDC. For weld metal where grain size is difficult to control, a change in grain orientation was found to improve resistance to DDC.« less

Improvement of thermal conductivities for silicone nanocomposite via incorporating poly(γ-methacryloxypropyltrimethoxy silane) grafted graphene fillers

NASA Astrophysics Data System (ADS)

Chen, Tian; Liu, Bo

2018-02-01

The proposed grafting polymerization of γ-methacryloxypropyltrimethoxy silane was performed to functionalize graphene, aiming to fabricate functionalized graphene/silicone with excellent thermal conductivities. The surface morphology and element content of poly(γ-methacryloxypropyltrimethoxy silane) grafted reduced graphene oxide (g-RGO) was characterized by Atomic force microscope (AFM) and X-ray photoelectron spectroscopy (XPS). The usage of g-RGO was benefit for improving the thermal conductivity of silicone (SI). The g-RGO/SI (2 wt% filler) had thermal conductivity of 1.31 W·m-1·K-1 and thermal diffusivity of 1.08 mm2·s-1 (increased by 620% compared to that of SI), which held potential for electronic packaging materials and micro-electro-mechanical systems apparatus.

The duration of hyaluronidase and optimal timing of hyaluronic acid (HA) filler reinjection after hyaluronidase injection.

PubMed

Kim, H J; Kwon, S B; Whang, K U; Lee, J S; Park, Y L; Lee, S Y

2018-02-01

Hyaluronidase injection is a commonly performed treatment for overcorrection or misplacement of hyaluronic acid (HA) filler. Many patients often wants the HA filler reinjection after the use of hyaluronidase, though the optimal timing of reinjection of HA filler still remains unknown. To provide the optimal time interval between hyaluronidase injections and HA filler reinjections. 6 Sprague-Dawley rats were injected with single monophasic HA filler. 1 week after injection, the injected sites were treated with hyaluronidase. Then, HA fillers were reinjected sequentially with differing time intervals from 30 minutes to 14 days. 1 hour after the reinjection of the last HA filler, all injection sites were excised for histologic evaluation. 3 hours after reinjection of HA filler, the appearance of filler material became evident again, retaining its shape and volume. 6 hours after reinjection, the filler materials restored almost its original volume and there were no significant differences from the positive control. Our data suggest that the hyaluronidase loses its effect in dermis and subcutaneous tissue within 3-6 hours after the injection and successful engraftment of reinjected HA filler can be accomplished 6 hours after the injection.

Effect of precipitated calcium carbonate--Cellulose nanofibrils composite filler on paper properties.

PubMed

He, Ming; Cho, Byoung-Uk; Won, Jong Myoung

2016-01-20

A new concept of composite filler was developed by using cellulose nanofibrils (CNF), precipitated calcium carbonate (PCC) and cationic starch (C-starch). In this study, cellulose nanofibrils were utilized in two different ways: a PCC-CNF composite filler and a papermaking additive in sheet forming. The aim was to elucidate their effects on flocculation, filler retention and the strength and optical properties of handsheets. The highest filler retention was obtained by using the PCC-CNF composite filler in paper sheets. The paper filled with the composite fillers had much higher bursting and tensile strengths than conventional PCC loading. It was also found that the paper prepared with PCC-CNF composite fillers became denser with increasing the filler content of paper. Copyright © 2015 Elsevier Ltd. All rights reserved.

Evaluation of mechanical properties and durability performance of HDPE-wood composites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tazi, M.; Erchiqui, F.; Kaddami, H.

The objective of this work is to evaluate the mechanical properties and durability performance of bio-composite materials made from sawdust and thermoplastic polymer (HDPE). For the preparation of the composites, sawdust in different proportions with Maleic Anhydride grafted Polyethylene (MAPE) as the coupling agent was used. The thermal and mechanical properties were successively characterized. The results indicate that adding wood fillers to a polymer matrix increases the degree of crystallinity and improves the tensile strength and ductility of composites. On the contrary, resistance to water absorption decreases as a function of the wood fillers. Scanning electron microscopy (SEM) was usedmore » to analyze morphological structure alteration when exposed to intense weathering. The biodegradability of bio-composites up to 97 days was also investigated; the results indicate that, by increasing the filler content, the amount of weight loss increased as well. In other words, even though the addition of sawdust to thermoplastic polymer improves the mechanical performance of a composite material, it also accelerates the biodegradation rate of the composite. An optimum amount of filler content might compromise the effect of biodegradation and mechanical properties of composite materials.« less

A screening method based on UV-Visible spectroscopy and multivariate analysis to assess addition of filler juices and water to pomegranate juices.

PubMed

Boggia, Raffaella; Casolino, Maria Chiara; Hysenaj, Vilma; Oliveri, Paolo; Zunin, Paola

2013-10-15

Consumer demand for pomegranate juice has considerably grown, during the last years, for its potential health benefits. Since it is an expensive functional food, cheaper fruit juices addition (i.e., grape and apple juices) or its simple dilution, or polyphenols subtraction are deceptively used. At present, time-consuming analyses are used to control the quality of this product. Furthermore these analyses are expensive and require well-trained analysts. Thus, the purpose of this study was to propose a high-speed and easy-to-use shortcut. Based on UV-VIS spectroscopy and chemometrics, a screening method is proposed to quickly screening some common fillers of pomegranate juice that could decrease the antiradical scavenging capacity of pure products. The analytical method was applied to laboratory prepared juices, to commercial juices and to representative experimental mixtures at different levels of water and filler juices. The outcomes were evaluated by means of multivariate exploratory analysis. The results indicate that the proposed strategy can be a useful screening tool to assess addition of filler juices and water to pomegranate juices. Copyright © 2012 Elsevier Ltd. All rights reserved.

Numerical Investigation of T-joints with 3D Four Directional Braided Composite Fillers Under Tensile Loading

NASA Astrophysics Data System (ADS)

Li, Xiao-kang; Liu, Zhen-guo; Hu, Long; Wang, Yi-bo; Lei, Bing; Huang, Xiang

2017-02-01

Numerical studied on T-joints with three-dimensional four directional (3D4D) braided composite fillers was presented in this article. Compared with conventional unidirectional prepreg fillers, the 3D braided composite fillers have excellent ability to prevent crack from penetrating trigone fillers, which constantly occurred in the conventional fillers. Meanwhile, the 3D braided composite fillers had higher fiber volume fraction and eliminated the fiber folding problem in unidirectional prepreg fillers. The braiding technology and mechanical performance of 3D4D braided fillers were studied. The numerical model of carbon fiber T-joints with 3D4D braided composite fillers was built by finite element analysis software. The damage formation, extension and failing process of T-joints with 3D4D braided fillers under tensile load were investigated. Further investigation was extended to the effect of 3D4D braided fillers with different braiding angles on mechanical behavior of the T-joints. The study results revealed that the filling area was the weakest part of the T-joints where the damage first appeared and the crack then rapidly spread to the glue film around the filling area and the interface between over-laminate and soleplate. The 3D4D braided fillers were undamaged and the braiding angle change induced a little effect on the bearing capacity of T-joints.

Property Relationship in Organosilanes and Nanotubes Filled Polypropylene Hybrid Composites

PubMed Central

Monsiváis-Barrón, Alejandra J.; Bonilla-Rios, Jaime; Sánchez-Fernández, Antonio

2014-01-01

Polypropylene composites with different filler contents were prepared by creating a masterbatch containing 3 wt%. filler. A variety of silanol groups were used to synthetized three compounds in different media trough a sol-gel process with acetic acid, formic acid and ammonium hydroxide as catalysts. Besides, four different nanotubular fillers were also used to analyze their behavior and compare it with the effect caused by the silanol groups. These tubular structures comprise: unmodified halloysite, carbon nanotubes and functionalized halloysite and carbon nanotubes. Morphological characterization in SEM and STEM/TEM showed dispersion in the polypropylene matrix. According to TGA and DSC measurements thermal behavior remain similar for all the composites. Mechanical test in tension demonstrate that modulus of the composites increases for all samples with a major impact for materials containing silanol groups synthetized in formic acid. Rheological measurements show a significantly increment in viscosity for samples containing unmodified and modified carbon nanotubes. No difference was found for samples containing silanol groups and halloysite when compared to neat polypropylene. Finally, the oxygen transmission rate increased for all samples showing high barrier properties only for samples containing natural and functionalized halloysite nanotubes. PMID:28788233

Ultra-high dispersion of graphene in polymer composite via solvent free fabrication and functionalization

PubMed Central

Noh, Ye Ji; Joh, Han-Ik; Yu, Jaesang; Hwang, Soon Hyoun; Lee, Sungho; Lee, Cheol Ho; Kim, Seong Yun; Youn, Jae Ryoun

2015-01-01

The drying process of graphene-polymer composites fabricated by solution-processing for excellent dispersion is time consuming and suffers from a restacking problem. Here, we have developed an innovative method to fabricate polymer composites with well dispersed graphene particles in the matrix resin by using solvent free powder mixing and in-situ polymerization of a low viscosity oligomer resin. We also prepared composites filled with up to 20 wt% of graphene particles by the solvent free process while maintaining a high degree of dispersion. The electrical conductivity of the composite, one of the most significant properties affected by the dispersion, was consistent with the theoretically obtained effective electrical conductivity based on the mean field micromechanical analysis with the Mori-Tanaka model assuming ideal dispersion. It can be confirmed by looking at the statistical results of the filler-to-filler distance obtained from the digital processing of the fracture surface images that the various oxygenated functional groups of graphene oxide can help improve the dispersion of the filler and that the introduction of large phenyl groups to the graphene basal plane has a positive effect on the dispersion. PMID:25771823

Property Relationship in Organosilanes and Nanotubes Filled Polypropylene Hybrid Composites.

PubMed

Monsiváis-Barrón, Alejandra J; Bonilla-Rios, Jaime; Sánchez-Fernández, Antonio

2014-10-20

Polypropylene composites with different filler contents were prepared by creating a masterbatch containing 3 wt%. filler. A variety of silanol groups were used to synthetized three compounds in different media trough a sol-gel process with acetic acid, formic acid and ammonium hydroxide as catalysts. Besides, four different nanotubular fillers were also used to analyze their behavior and compare it with the effect caused by the silanol groups. These tubular structures comprise: unmodified halloysite, carbon nanotubes and functionalized halloysite and carbon nanotubes. Morphological characterization in SEM and STEM/TEM showed dispersion in the polypropylene matrix. According to TGA and DSC measurements thermal behavior remain similar for all the composites. Mechanical test in tension demonstrate that modulus of the composites increases for all samples with a major impact for materials containing silanol groups synthetized in formic acid. Rheological measurements show a significantly increment in viscosity for samples containing unmodified and modified carbon nanotubes. No difference was found for samples containing silanol groups and halloysite when compared to neat polypropylene. Finally, the oxygen transmission rate increased for all samples showing high barrier properties only for samples containing natural and functionalized halloysite nanotubes.

Thermal aging of interfacial polymer chains in ethylene-propylene-diene terpolymer/aluminum hydroxide composites: solid-state NMR study.

PubMed

Gabrielle, Brice; Lorthioir, Cédric; Lauprêtre, Françoise

2011-11-03

The possible influence of micrometric-size filler particles on the thermo-oxidative degradation behavior of the polymer chains at polymer/filler interfaces is still an open question. In this study, a cross-linked ethylene-propylene-diene (EPDM) terpolymer filled by aluminum trihydrate (ATH) particles is investigated using (1)H solid-state NMR. The time evolution of the EPDM network microstructure under thermal aging at 80 °C is monitored as a function of the exposure time and compared to that of an unfilled EPDM network displaying a similar initial structure. While nearly no variations of the topology are observed on the neat EPDM network over 5 days at 80 °C, a significant amount of chain scission phenomena are evidenced in EPDM/ATH. A specific surface effect induced by ATH on the thermodegradative properties of the polymer chains located in their vicinity is thus pointed out. Close to the filler particles, a higher amount of chain scissions are detected, and the characteristic length scale related to these interfacial regions displaying a significant thermo-oxidation process is determined as a function of the aging time.

Effect of filler properties in composite resins on light transmittance characteristics and color.

PubMed

Arikawa, Hiroyuki; Kanie, Takahito; Fujii, Koichi; Takahashi, Hideo; Ban, Seiji

2007-01-01

The purpose of this investigation was to examine the effect of filler particle size and shape as well as filler content on light transmittance characteristics and color of experimental composite resins. A mixture of 30 mol% Bis-GMA and 70 mol% TEGDMA was prepared as a base monomer and to which a photoinitiator (camphorquinone) and a co-initiator (N,N-dimethylaminoethyl methacrylate) were added. Four different irregular- and spherical-shaped filler types with an average particle size of 1.9-11.1 microm were added to the mixture in three different filler contents of 20, 30, and 40 vol%. Light transmittance characteristics including light diffusion characteristics of the materials were evaluated. Color values and color differences among filler contents of the materials were also determined. Materials containing smaller and irregular-shaped fillers showed higher light transmittance and diffusion angle distribution with a sharper peak, as compared with those containing larger and spherical-shape fillers. It was also found that there was a significant correlation between the specific surface area of fillers and the color difference of the materials containing the fillers. Our results indicated that the shape of filler particles, as well as particle size and filler content, significantly affected the light transmittance characteristics--including light diffusion characteristics--and color of composite resins.

Preparation, characterization, and surface conductivity of nanocomposites with hollow graphitic carbon nanospheres as fillers in polymethylmethacrylate matrix

NASA Astrophysics Data System (ADS)

Zhang, Cheng; Gao, Qingshan; Zhou, Bing; Bhargava, Gaurang

2017-08-01

Hollow graphitized carbon nanosphere (CNS) materials with inner diameter of 20 to 50 nm and shell thickness of 10 15 nm were synthesized from the polymerization of resorcinol (R) and formaldehyde (F) in the presence of a well-characterized iron polymeric complex (IPC). The CNS with unique nanostructures was used to fabricate CNS-polymer composites by dispersing CNS as fillers in the polymer matrix. Aggregation of CNS in polymer composites is usually a challenging issue. In this work, we employed in situ polymerization method and melt-mixing method to fabricate CNS-polymethylmethacrylate (PMMA) composites and compared their difference in terms of CNS dispersion in the composites and surface electrical conductivity. Four probes technique was utilized to measure the surface electrical conductivity of the CNS-PMMA composites. The measurements on four points and four silver painted lines on the thin film of CNS-PMMA composites were compared. The in situ polymerization method was found more efficient for better CNS dispersion in PMMA matrix and lower percolation conductivity threshold compared to the melt-mixing method. The enhanced electrical conductivity for CNS-PMMA composites may be attributed to the stronger covalent CNS-PMMA bonding between the surface functional groups and the MMA moieties.

Glass transition temperature of polymer nano-composites with polymer and filler interactions

NASA Astrophysics Data System (ADS)

Hagita, Katsumi; Takano, Hiroshi; Doi, Masao; Morita, Hiroshi

2012-02-01

We systematically studied versatile coarse-grained model (bead spring model) to describe filled polymer nano-composites for coarse-grained (Kremer-Grest model) molecular dynamics simulations. This model consists of long polymers, crosslink, and fillers. We used the hollow structure as the filler to describe rigid spherical fillers with small computing costs. Our filler model consists of surface particles of icosahedra fullerene structure C320 and a repulsive force from the center of the filler is applied to the surface particles in order to make a sphere and rigid. The filler's diameter is 12 times of beads of the polymers. As the first test of our model, we study temperature dependence of volumes of periodic boundary conditions under constant pressures through NPT constant Andersen algorithm. It is found that Glass transition temperature (Tg) decrease with increasing filler's volume fraction for the case of repulsive interaction between polymer and fillers and Tg weakly increase for attractive interaction.

Effect of biobased fillers nature on biodeterioration of hybrid polyethylene composites by mold fungi

NASA Astrophysics Data System (ADS)

Mastalygina, E. E.; Popov, A. A.; Pantyukhov, P. V.

2017-06-01

The paper is devoted to investigation of deterioration of natural fillers and polyethylene composites on their basis (polyethylene/filler=70/30) due to the action of mold fungi. The fillers chemical composition, dimensional parameters and biodegradability have been analyzed as factors exert a considerable impact on composite materials biodeterioration. It has been found that the principal factor determining the biodeterioration of polyethylene/filler composites by mold fungi is chemical composition of a filler and, in turn, its biodegradability. The excess of holocellulose content over lignin content and high protein content in a filler are able to induce biofouling of the polymeric composite materials. The presence of soluble and easy hydrolysed fraction in a filler increases its availability in a polymeric matrix. According to the study results, most effective natural fillers as additives stimulating polyethylene composites biodegradability are milled straw of seed flax and hydrolyzed keratin of bird’s feather.

The improvement in functional characteristics of eco-friendly composites made of natural rubber and cellulose

DOE Office of Scientific and Technical Information (OSTI.GOV)

Araki, Kunihiro; Kaneko, Shonosuke; Matsumoto, Koki

We investigated the efficient use of cellulose to resolve the problem of the depletion of fossil resources. In this study, as the biomass material, the green composite based on natural rubber (NR) and the flake-shaped cellulose particles (FSCP) was produced. In order to further improvement of functional characteristics, epoxidized natural rubber (ENR) was also used instead of NR. The FSCP were produced by mechanical milling in a planetary ball mill with a grinding aid as a cellulose aggregation inhibitor. Moreover, talc and mica particles were used to compare with FSCP. NR and ENR was mixed with vulcanizing agents and thenmore » each filler was added to NR compound in an internal mixer. The vulcanizing agents are as follows: stearic acid, zinc oxide, sulfur, and vulcanization accelerator. The functionalities of the composites were evaluated by a vibration-damping experiment and a gas permeability experiment. As a result, we found that FSCP filler has effects similar to (or more than) inorganic filler in vibration-damping and O{sub 2} barrier properties. And then, vibration- damping and O{sub 2} barrier properties of the composite including FSCP was increased with use of ENR. In particular, we found that ENR-50 composite containing 50 phr FSCP has three times as high vibration-damping property as ENR-50 without FSCP.« less

Dielectric properties of magnetorheological elastomers with different microstructure

NASA Astrophysics Data System (ADS)

Moucka, R.; Sedlacik, M.; Cvek, M.

2018-03-01

Composite materials containing magnetic particles organised within the polymer matrix by the means of an external magnetic field during the curing process were prepared, and their dielectric properties were compared with their isotropic analogues of the same filler concentration but homogeneous spatial distribution. A substantial dielectric response observed for anisotropic systems in a form of relaxation processes was explained as charge transport via the mechanism of variable range hopping. The changes in registered relaxations' critical frequency and shape of dielectric spectra with the filler concentration were discussed in terms of decreasing anisotropy of the system. The knowledge of the dielectric response of studied systems is essential for their practical applications such as piezoresistive sensors or radio-absorbing materials.

Hyaluron Filler Containing Lidocaine on a CPM Basis for Lip Augmentation: Reports from Practical Experience.

PubMed

Fischer, Tanja C; Sattler, Gerhard; Gauglitz, Gerd G

2016-06-01

Lip augmentation with hyaluronic acid fillers is established. As monophasic polydensified hyaluronic acid products with variable density, CPM-HAL1 (Belotero Balance Lidocaine, Merz Aesthetics, Raleigh, NC) and CPM-HAL2 (Belotero Intense Lidocaine, Merz Aesthetics, Raleigh, NC) are qualified for beautification and particularly natural-looking rejuvenation, respectively. The aim of this article was to assess the handling and outcome of lip augmentation using the lidocaine-containing hyaluronic acid fillers, CPM-HAL1 and CPM-HAL2. Data were documented from patients who received lip augmentation by means of beautification and/or rejuvenation using CPM-HAL1 and/or CPM-HAL2. Observation period was 4 months, with assessment of natural outcome, evenness, distribution, fluidity, handling, malleability, tolerability, as well as patient satisfaction and pain. A total of 146 patients from 21 German centers participated. Physicians rated natural outcome and evenness as good or very good for more than 95% of patients. Distribution, fluidity, handling, and malleability were assessed for both fillers as good or very good in more than 91% of patients. At every evaluation point, more than 93% of patients were very or very much satisfied with the product. A total of 125 patients (85.6%) experienced transient injection-related side effects. Pain intensity during the procedure was mild (2.72 ± 1.72 on the 0-10 pain assessment scale) and abated markedly within 30 minutes (0.42 ± 0.57). Lip augmentation with hyaluronic acid fillers produced a long-term cosmetic result. Due to the lidocaine content, procedural pain was low and transient. Accordingly, a high degree of patient satisfaction was achieved that was maintained throughout the observation period. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

A quality by design approach to investigate the effect of mannitol and dicalcium phosphate qualities on roll compaction.

PubMed

Souihi, Nabil; Dumarey, Melanie; Wikström, Håkan; Tajarobi, Pirjo; Fransson, Magnus; Svensson, Olof; Josefson, Mats; Trygg, Johan

2013-04-15

Roll compaction is a continuous process for solid dosage form manufacturing increasingly popular within pharmaceutical industry. Although roll compaction has become an established technique for dry granulation, the influence of material properties is still not fully understood. In this study, a quality by design (QbD) approach was utilized, not only to understand the influence of different qualities of mannitol and dicalcium phosphate (DCP), but also to predict critical quality attributes of the drug product based solely on the material properties of that filler. By describing each filler quality in terms of several representative physical properties, orthogonal projections to latent structures (OPLS) was used to understand and predict how those properties affected drug product intermediates as well as critical quality attributes of the final drug product. These models were then validated by predicting product attributes for filler qualities not used in the model construction. The results of this study confirmed that the tensile strength reduction, known to affect plastic materials when roll compacted, is not prominent when using brittle materials. Some qualities of these fillers actually demonstrated improved compactability following roll compaction. While direct compression qualities are frequently used for roll compacted drug products because of their excellent flowability and good compaction properties, this study revealed that granules from these qualities were more poor flowing than the corresponding powder blends, which was not seen for granules from traditional qualities. The QbD approach used in this study could be extended beyond fillers. Thus any new compound/ingredient would first be characterized and then suitable formulation characteristics could be determined in silico, without running any additional experiments. Copyright © 2013 Elsevier B.V. All rights reserved.

[Lidocaine-containing hyaluronic acid filler on a CPM® basis for lip augmentation : Experience from clinical practice].

PubMed

Fischer, T; Sattler, G; Gauglitz, G

2016-06-01

Lip augmentation with hyaluronic acid fillers is an established procedure. As monophasic polydensified hyaluronic acid products with variable density CPM-HAL1 (Belotero® Balance Lidocaine) and CPM-HAL2 (Belotero® Intense Lidocaine) are qualified for beautification and particularly natural-looking rejuvenation, respectively. Assessment of handling and outcome of lip augmentation using the lidocaine-containing hyaluronic acid fillers CPM-HAL1 and CPM-HAL2. Data from patients who received lip augmentation by means of bautification and/or rejuvenation using CPM-HAL1 and/or CPM-HAL2 were documented. Observation period was 4 months, with assessment of natural outcome, evenness, handling, fluidity, distribution, malleability, tolerability, as well as patient satisfaction and pain. In total, 146 patients from 21 German centres participated. Physicians rated natural outcome and evenness as good or very good for > 95 % of patients. Handling, fluidity, distribution and malleability were assessed for both fillers as good or very good in > 91 % of patients. At every evaluation point, more than 93 % of patients were very or very much satisfied with the product. A total of 125 patients (85.6 %) experienced transient injection-related side effects. Pain intensity during the procedure was mild (2.72 ± 1.72 on the 0-10 pain assessment scale) and abated markedly within 30 min (0.42 ± 0.57). Lip augmentation with hyaluronic acid fillers produced a long-term cosmetic result. Due to the lidocaine content, procedural pain was low and transient. Accordingly, a high degree of patient satisfaction was achieved that was maintained throughout the observation period.

Phenomenological Modeling and Laboratory Simulation of Long-Term Aging of Asphalt Mixtures

NASA Astrophysics Data System (ADS)

Elwardany, Michael Dawoud

The accurate characterization of asphalt mixture properties as a function of pavement service life is becoming more important as more powerful pavement design and performance prediction methods are implemented. Oxidative aging is a major distress mechanism of asphalt pavements. Aging increases the stiffness and brittleness of the material, which leads to a high cracking potential. Thus, an improved understanding of the aging phenomenon and its effect on asphalt binder chemical and rheological properties will allow for the prediction of mixture properties as a function of pavement service life. Many researchers have conducted laboratory binder thin-film aging studies; however, this approach does not allow for studying the physicochemical effects of mineral fillers on age hardening rates in asphalt mixtures. Moreover, aging phenomenon in the field is governed by kinetics of binder oxidation, oxygen diffusion through mastic phase, and oxygen percolation throughout the air voids structure. In this study, laboratory aging trials were conducted on mixtures prepared using component materials of several field projects throughout the USA and Canada. Laboratory aged materials were compared against field cores sampled at different ages. Results suggested that oven aging of loose mixture at 95°C is the most promising laboratory long-term aging method. Additionally, an empirical model was developed in order to account for the effect of mineral fillers on age hardening rates in asphalt mixtures. Kinetics modeling was used to predict field aging levels throughout pavement thickness and to determine the required laboratory aging duration to match field aging. Kinetics model outputs are calibrated using measured data from the field to account for the effects of oxygen diffusion and percolation. Finally, the calibrated model was validated using independent set of field sections. This work is expected to provide basis for improved asphalt mixture and pavement design procedures in order to save taxpayers' money.

A regression analysis of filler particle content to predict composite wear.

PubMed

Jaarda, M J; Wang, R F; Lang, B R

1997-01-01

It has been hypothesized that composite wear is correlated to filler particle content. There is a paucity of research to substantiate this theory despite numerous projects evaluating the correlation. The purpose of this study was to determine whether a linear relationship existed between composite wear and filler particle content of 12 composites. In vivo wear data had been previously collected for the 12 composites and served as basis for this study. Scanning electron microscopy and backscatter electron imaging were combined with digital imaging analysis to develop "profile maps" of the filler particle composition of the composites. These profile maps included eight parameters: (1) total number of filler particles/28742.6 microns2, (2) percent of area occupied by all of the filler particles, (3) mean filler particle size, (4) percent of area occupied by the matrix, (5) percent of area occupied by filler particles, r (radius) 1.0 < or = micron, (6) percent of area occupied by filler particles, r = 1.0 < or = 4.5 microns, (7) percent of area occupied by filler particles, r = 4.5 < or = 10 microns, and (8) percent of area occupied by filler particles, r > 10 microns. Forward stepwise regression analyses were used with composite wear as the dependent variable and the eight parameters as independent variables. The results revealed a linear relationship between composite wear and the filler particle content. A mathematical formula was developed to predict composite wear.

Hardness of model dental composites - the effect of filler volume fraction and silanation.

PubMed

McCabe, J F; Wassell, R W

1999-05-01

The relationship between structure and mechanical properties for dental composites has often proved difficult to determine due to the use of commercially available materials having a number of differences in composition i.e. different type of resin, different type of filler, etc. This makes a scientific study of any one variable such as filler content difficult if not impossible. In the current study it was the aim to test the hypothesis that hardness measurements of dental composites could be used to monitor the status of the resin-filler interface and to determine the efficacy of any particle silanation process. Ten model composites formulated from a single batch of resin and containing a common type of glass filler were formulated to contain varying amounts of filler. Some materials contained silanated filler, others contained unsilanated filler. Specimens were prepared and stored in water and hardness (Vickers') was determined at 24 h using loads of 50, 100, 200 and 300 g. Composites containing silanated fillers were significantly harder than materials containing unsilanated fillers. For unsilanated products hardness was independent of applied load and in this respect they behaved like homogeneous materials. For composites containing silanated fillers there was a marked increase in measured hardness as applied load was increased. This suggests that the hardness-load profile could be used to monitor the status of the resin-filler interface. Copyright 1999 Kluwer Academic Publishers

Effects of functionalization on thermal properties of single-wall and multi-wall carbon nanotube-polymer nanocomposites.

PubMed

Gulotty, Richard; Castellino, Micaela; Jagdale, Pravin; Tagliaferro, Alberto; Balandin, Alexander A

2013-06-25

Carboxylic functionalization (-COOH groups) of carbon nanotubes is known to improve their dispersion properties and increase the electrical conductivity of carbon-nanotube-polymer nanocomposites. We have studied experimentally the effects of this type of functionalization on the thermal conductivity of the nanocomposites. It was found that while even small quantities of carbon nanotubes (~1 wt %) can increase the electrical conductivity, a larger loading fraction (~3 wt %) is required to enhance the thermal conductivity of nanocomposites. Functionalized multi-wall carbon nanotubes performed the best as filler material leading to a simultaneous improvement of the electrical and thermal properties of the composites. Functionalization of the single-wall carbon nanotubes reduced the thermal conductivity enhancement. The observed trends were explained by the fact that while surface functionalization increases the coupling between carbon nanotube and polymer matrix, it also leads to formation of defects, which impede the acoustic phonon transport in the single-wall carbon nanotubes. The obtained results are important for applications of carbon nanotubes and graphene flakes as fillers for improving thermal, electrical and mechanical properties of composites.

21 CFR 888.3045 - Resorbable calcium salt bone void filler device.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Resorbable calcium salt bone void filler device... salt bone void filler device. (a) Identification. A resorbable calcium salt bone void filler device is... entitled “Class II Special Controls Guidance: Resorbable Calcium Salt Bone Void Filler Device; Guidance for...

21 CFR 888.3045 - Resorbable calcium salt bone void filler device.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Resorbable calcium salt bone void filler device... salt bone void filler device. (a) Identification. A resorbable calcium salt bone void filler device is... entitled “Class II Special Controls Guidance: Resorbable Calcium Salt Bone Void Filler Device; Guidance for...

21 CFR 888.3045 - Resorbable calcium salt bone void filler device.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Resorbable calcium salt bone void filler device... salt bone void filler device. (a) Identification. A resorbable calcium salt bone void filler device is... entitled “Class II Special Controls Guidance: Resorbable Calcium Salt Bone Void Filler Device; Guidance for...

21 CFR 888.3045 - Resorbable calcium salt bone void filler device.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Resorbable calcium salt bone void filler device... salt bone void filler device. (a) Identification. A resorbable calcium salt bone void filler device is... entitled “Class II Special Controls Guidance: Resorbable Calcium Salt Bone Void Filler Device; Guidance for...

21 CFR 888.3045 - Resorbable calcium salt bone void filler device.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Resorbable calcium salt bone void filler device... salt bone void filler device. (a) Identification. A resorbable calcium salt bone void filler device is... entitled “Class II Special Controls Guidance: Resorbable Calcium Salt Bone Void Filler Device; Guidance for...

Aluminum Lithium Alloy 2195 Fusion Welding Improvements with New Filler Wire

NASA Technical Reports Server (NTRS)

Russell, Carolyn; Bjorkman, Gerry; McCool, Carolyn (Technical Monitor)

2000-01-01

A viewgraph presentation outlines NASA Marshall Space Flight Center, Lockheed Martin Michoud Space Systems, and McCook Metals' development an aluminum-copper weld filler wire for fusion welding 2195 aluminum lithium. The aluminum-copper based weld filler wire has been identified as B218, which is the result of six years of weld filler wire development funded by NASA, Lockheed Martin, and McCook Metals. The Super Lightweight External Tank for the NASA Space Shuttle Program consists of 2195 welded with 4043 aluminum-silicon weld filler wire. The B218 filler wire chemistry was developed to produce enhanced 2195 weld and repair weld mechanical properties. An initial characterization of the B218 weld filler wire was performed consisting of initial weld and repair weld evaluation comparing B218 and 4043. The testing involved room temperature and cryogenic tensile testing along with fracture toughness testing. B218 weld filler wire proved to produce enhanced initial and repair weld tensile and fracture properties over 4043. B218 weld filler wire has proved to be a superior weld filler wire for welding 2195 and other aluminum lithium alloys over 4043.

Autonomous Slat-Cove-Filler Device for Reduction of Aeroacoustic Noise Associated with Aircraft Systems

NASA Technical Reports Server (NTRS)

Turner, Travis L. (Inventor); Kidd, Reggie T. (Inventor); Lockard, David P (Inventor); Khorrami, Mehdi R. (Inventor); Streett, Craig L. (Inventor); Weber, Douglas Leo (Inventor)

2016-01-01

A slat cove filler is utilized to reduce airframe noise resulting from deployment of a leading edge slat of an aircraft wing. The slat cove filler is preferably made of a super elastic shape memory alloy, and the slat cove filler shifts between stowed and deployed shapes as the slat is deployed. The slat cove filler may be configured such that a separate powered actuator is not required to change the shape of the slat cove filler from its deployed shape to its stowed shape and vice-versa. The outer contour of the slat cove filler preferably follows a profile designed to maintain accelerating flow in the gap between the slat cove filler and wing leading edge to provide for noise reduction.

Electrical and Mechanical Properties of 3D-Printed Graphene-Reinforced Epoxy

NASA Astrophysics Data System (ADS)

Compton, Brett G.; Hmeidat, Nadim S.; Pack, Robert C.; Heres, Maximilian F.; Sangoro, Joshua R.

2018-03-01

Recent developments in additive manufacturing have demonstrated the potential for thermoset polymer feedstock materials to achieve high strength, stiffness, and functionality through incorporation of structural and functional filler materials. In this work, graphene was investigated as a potential filler material to provide rheological properties necessary for direct-write three-dimensional (3D) printing and electrostatic discharge properties to the printed component. The rheological properties of epoxy/graphene mixtures were characterized, and printable epoxy/graphene inks formulated. Sheet resistance values for printed epoxy/graphene composites ranged from 0.67 × 102 Ω/sq to 8.2 × 103 Ω/sq. The flexural strength of printed epoxy/graphene composites was comparable to that of cast neat epoxy ( 80 MPa), suggesting great potential for these new materials in multifunctional 3D-printed devices.

40 CFR 418.71 - Specialized definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... this subpart. (b) The term mixed fertilizer shall mean a mixture of wet and/or dry straight fertilizer materials, mixed fertilizer materials, fillers and additives prepared through chemical reaction to a given... STANDARDS FERTILIZER MANUFACTURING POINT SOURCE CATEGORY Mixed and Blend Fertilizer Production Subcategory...

40 CFR 418.71 - Specialized definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... this subpart. (b) The term mixed fertilizer shall mean a mixture of wet and/or dry straight fertilizer materials, mixed fertilizer materials, fillers and additives prepared through chemical reaction to a given... STANDARDS FERTILIZER MANUFACTURING POINT SOURCE CATEGORY Mixed and Blend Fertilizer Production Subcategory...

40 CFR 418.71 - Specialized definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... this subpart. (b) The term mixed fertilizer shall mean a mixture of wet and/or dry straight fertilizer materials, mixed fertilizer materials, fillers and additives prepared through chemical reaction to a given... STANDARDS FERTILIZER MANUFACTURING POINT SOURCE CATEGORY Mixed and Blend Fertilizer Production Subcategory...

40 CFR 418.71 - Specialized definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... apply to this subpart. (b) The term mixed fertilizer shall mean a mixture of wet and/or dry straight fertilizer materials, mixed fertilizer materials, fillers and additives prepared through chemical reaction to... AND STANDARDS FERTILIZER MANUFACTURING POINT SOURCE CATEGORY Mixed and Blend Fertilizer Production...

40 CFR 418.71 - Specialized definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... this subpart. (b) The term mixed fertilizer shall mean a mixture of wet and/or dry straight fertilizer materials, mixed fertilizer materials, fillers and additives prepared through chemical reaction to a given... STANDARDS FERTILIZER MANUFACTURING POINT SOURCE CATEGORY Mixed and Blend Fertilizer Production Subcategory...

Does filler database size influence identification accuracy?

PubMed

Bergold, Amanda N; Heaton, Paul

2018-06-01

Police departments increasingly use large photo databases to select lineup fillers using facial recognition software, but this technological shift's implications have been largely unexplored in eyewitness research. Database use, particularly if coupled with facial matching software, could enable lineup constructors to increase filler-suspect similarity and thus enhance eyewitness accuracy (Fitzgerald, Oriet, Price, & Charman, 2013). However, with a large pool of potential fillers, such technologies might theoretically produce lineup fillers too similar to the suspect (Fitzgerald, Oriet, & Price, 2015; Luus & Wells, 1991; Wells, Rydell, & Seelau, 1993). This research proposes a new factor-filler database size-as a lineup feature affecting eyewitness accuracy. In a facial recognition experiment, we select lineup fillers in a legally realistic manner using facial matching software applied to filler databases of 5,000, 25,000, and 125,000 photos, and find that larger databases are associated with a higher objective similarity rating between suspects and fillers and lower overall identification accuracy. In target present lineups, witnesses viewing lineups created from the larger databases were less likely to make correct identifications and more likely to select known innocent fillers. When the target was absent, database size was associated with a lower rate of correct rejections and a higher rate of filler identifications. Higher algorithmic similarity ratings were also associated with decreases in eyewitness identification accuracy. The results suggest that using facial matching software to select fillers from large photograph databases may reduce identification accuracy, and provides support for filler database size as a meaningful system variable. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Fillers in dermatology: from past to present.

PubMed

Chacon, Anna H

2015-11-01

Injectable fillers were introduced in dermatology as a method for reconstructing facial deformities and restoring the aging face. Although fillers have become a popular option among cosmetic patients, clinical experience has shown that fillers must be used with caution, as complications can occur. This article provides a brief review of the history of filler agents currently available for soft tissue augmentation. Although no single filler is ideal for all patients, indications, and situations, residents should be aware of the properties and characteristics that make each product unique.

The impact of fillers on lineup performance.

PubMed

Wetmore, Stacy A; McAdoo, Ryan M; Gronlund, Scott D; Neuschatz, Jeffrey S

2017-01-01

Filler siphoning theory posits that the presence of fillers (known innocents) in a lineup protects an innocent suspect from being chosen by siphoning choices away from that innocent suspect. This mechanism has been proposed as an explanation for why simultaneous lineups (viewing all lineup members at once) induces better performance than showups (one-person identification procedures). We implemented filler siphoning in a computational model (WITNESS, Clark, Applied Cognitive Psychology 17:629-654, 2003), and explored the impact of the number of fillers (lineup size) and filler quality on simultaneous and sequential lineups (viewing lineups members in sequence), and compared both to showups. In limited situations, we found that filler siphoning can produce a simultaneous lineup performance advantage, but one that is insufficient in magnitude to explain empirical data. However, the magnitude of the empirical simultaneous lineup advantage can be approximated once criterial variability is added to the model. But this modification works by negatively impacting showups rather than promoting more filler siphoning. In sequential lineups, fillers were found to harm performance. Filler siphoning fails to clarify the relationship between simultaneous lineups and sequential lineups or showups. By incorporating constructs like filler siphoning and criterial variability into a computational model, and trying to approximate empirical data, we can sort through explanations of eyewitness decision-making, a prerequisite for policy recommendations.

Cross-Beam Laser Joining of AA 6111 to Galvanized Steel in a Coach Peel Configuration

NASA Astrophysics Data System (ADS)

Yang, Guang; Mohammadpour, Masoud; Yazdian, Nima; Ma, Junjie; Carlson, Blair; Wang, Hui-Ping; Kovacevic, Radovan

2017-06-01

Cross-beam laser joining of aluminum alloy 6111 to hot-dip galvanized steel in the coach-peel configuration was investigated with the addition of AA 4047 filler wire. The filler material was not only brazed onto the galvanized steel but also partially fusion-welded with the aluminum panel. Through adjusting the laser power to 3.4 kW, a desirable wetting and spreading of filler wire on both panel surfaces could be achieved, and the thickness of intermetallic layer in the middle section of the interface between the weld bead and steel was less than 2 μm. To better understand the solid/liquid interfacial reaction at the brazing interface, two rotary Gaussian heat source models were introduced to simulate the temperature distribution in the molten pool by using the finite element method. Joint properties were examined in terms of microstructure and mechanical properties. During the tensile test, the fracture of coupons took place at the aluminum side rather than along the interface between the intermetallic layer and steel panel. No failure occurred during the three-point bending test.

Dispersed metal-toughened ceramics and ceramic brazing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moorhead, A.J.; Tiegs, T.N.; Lauf, R.J.

1983-01-01

An alumina (Al/sub 2/O/sub 3/) based material that contains approximately 1 vol % finely dispersed platinum or chromium was developed for use in high temperature thermal-shock resistant electrical insulators. The work at ORNL is divided into two areas: (1) development of DMT ceramics; and (2) development of brazing filler metals suitable for making ceramic-to-ceramic and ceramic-to-metal brazements. The DMT ceramics and brazements are intended for service at elevated temperatures and at high stress levels in the dirty environments of advanced heat engines. The development and characterization of DMT ceramics includes processing (powder preparation, densification and heat treatment) and detailed measurementmore » of mechanical and physical properties (strength, fracture toughness, and thermal conductivity). The brazing work includes: (1) the formulation and melting of small quantities of experimental brazing filler metals; (2) evaluation of the wetting and bonding behavior of these filler metals on Al/sub 2/O/sub 3/, partially stabilized zirconia and ..cap alpha..-SiC in a sessile drop apparatus; and (3) determine the short-term strength and fracture toughness of brazements.« less

Long-term stability of dental adhesive incorporated by boron nitride nanotubes.

PubMed

Degrazia, Felipe Weidenbach; Leitune, Vicente Castelo Branco; Visioli, Fernanda; Samuel, Susana Maria Werner; Collares, Fabrício Mezzomo

2018-03-01

The aim of this study was to evaluate physicochemical properties, long-term microtensile bond strength and cytotoxicity of methacrylate-based adhesive containing boron nitride nanotubes (BNNTs) as fillers. A dental adhesive was formulated using BisGMA/HEMA, 66/33wt% (control). Inorganic BNNT fillers were incorporated into the adhesive at different concentrations (0.05, 0.075, 0.1 and 0.15wt%). Analyses of degree of conversion (DC), polymerization rate [Rp.(s -1 )], contact angle (CA) on dentin, after 24h and 6 months microtensile bond strength (μTBS-24h and 6 months) were assessed. Cytotoxicity was performed through viability of fibroblast cells (%) by sulforhodamine B (SRB) colorimetry. DC and max. polymerization rate increased (p<0.05) after incorporating 0.075 and 0.1wt% BNNT. The contact angle on dentin increased (p<0.05) after incorporating 0.15wt% BNNT. The μTBS-24h showed no changes (p>0.05) after incorporating up to 0.15wt% BNNT comparing to control. After 6 months, μTBS decreased (p<0.05) for control and 0.15wt% BNNT and BNNT groups up to 0.15wt% showed higher μTBS than control (p<0.05). No difference of fibroblast growth was found among adhesives (p>0.05) and up to 19% of cell viability was found comparing 0.05wt% BNNT to positive control group (100%). Incorporating boron nitride nanotubes up to 0.1wt% into dental adhesive increased the long-term stability to dentin without decreasing viability of fibroblast cell growth. Thus, the use of BNNTs as filler may decrease failure rate of current dentinal adhesives. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Flame Retardant Effect of Nano Fillers on Polydimethylsiloxane Composites.

PubMed

Jagdale, Pravin; Salimpour, Samera; Islam, Md Hujjatul; Cuttica, Fabio; Hernandez, Francisco C Robles; Tagliaferro, Alberto; Frache, Alberto

2018-02-01

Polydimethylsiloxane has exceptional fire retardancy characteristics, which make it a popular polymer in flame retardancy applications. Flame retardancy of polydimethylsiloxane with different nano fillers was studied. Polydimethylsiloxane composite fire property varies because of the shape, size, density, and chemical nature of nano fillers. In house made carbon and bismuth oxide nano fillers were used in polydimethylsiloxane composite. Carbon from biochar (carbonised bamboo) and a carbon by-product (carbon soot) were selected. For comparative study of nano fillers, standard commercial multiwall carbon nano tubes (functionalised, graphitised and pristine) as nano fillers were selected. Nano fillers in polydimethylsiloxane positively affects their fire retardant properties such as total smoke release, peak heat release rate, and time to ignition. Charring and surface ceramization are the main reasons for such improvement. Nano fillers in polydimethylsiloxane may affect the thermal mobility of polymer chains, which can directly affect the time to ignition. The study concludes that the addition of pristine multiwall carbon nano tubes and bismuth oxide nano particles as filler in polydimethylsiloxane composite improves the fire retardant property.

Safety of radiofrequency treatment over human skin previously injected with medium-term injectable soft-tissue augmentation materials: a controlled pilot trial.

PubMed

Alam, Murad; Levy, Ross; Pajvani, Urvi; Pavjani, Urvi; Ramierez, James A; Guitart, Joan; Veen, Heather; Gladstone, Hayes B

2006-03-01

Several soft-tissue augmentation materials are now available for reduction of nasolabial fold creases and perioral rhytides. Nasolabial folds and perioral rhytides can also be improved by skin tightening delivered by non-ablative radiofrequency (RF) treatment. The purpose of this study was to assess the safety of RF treatment over skin areas recently injected with medium-term injectable soft-tissue augmentation materials. Five subjects were assigned to the experimental arm (augmentation materials plus RF) and one to the control arm (augmentation materials alone). Each subject received injections of 0.3 mL of hyaluronic acid derivative (Restylane) and calcium hydroxylapatite (Radiesse) 3 cm apart on the upper inner arm. Two weeks later, two non-overlapping passes of RF (Thermage ThermaCool TC) were delivered at 63.5 setting with medium-fast 1.5 cm2 tip over injected sites in all of the experimental subjects. Punch skin biopsies were obtained 3 days later from each of the two injection sites on each subject. Light microscopy and digital photomicrographs obtained at low, medium, and high power showed no difference between filler materials in experimental and control subjects. In both cases filler was evident at the deep dermal-subcutaneous junction. Nodule formation, foreign body extravasation, or hemorrhage/clot was not observed grossly or histologically. Subjects and physicians did not report any difference in signs and symptoms between the experimental and control arms. Slightly increased transitory pain was noted when RF was delivered over filler versus over normal skin. Applying RF treatment over the same area 2 weeks after deep dermal injection with hyaluronic acid derivatives or calcium hydroxylapatite does not appear to cause gross morphological changes in the filler material or surrounding skin. Further studies with different parameters are necessary to confirm these findings. 2006 Wiley-Liss, Inc.

46 CFR 56.75-5 - Filler metal.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Filler metal. 56.75-5 Section 56.75-5 Shipping COAST... Brazing § 56.75-5 Filler metal. (a) The filler metal used in brazing must be a nonferrous metal or alloy having a melting point above 1,000 °F. and below that of the metal being joined. The filler metal must...

46 CFR 56.75-5 - Filler metal.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 2 2011-10-01 2011-10-01 false Filler metal. 56.75-5 Section 56.75-5 Shipping COAST... Brazing § 56.75-5 Filler metal. (a) The filler metal used in brazing must be a nonferrous metal or alloy having a melting point above 1,000 °F. and below that of the metal being joined. The filler metal must...

The Microstructural Evolution of Vacuum Brazed 1Cr18Ni9Ti Using Various Filler Metals

PubMed Central

Chen, Yunxia; Cui, Haichao; Lu, Binfeng; Lu, Fenggui

2017-01-01

The microstructures and weldability of a brazed joint of 1Cr18Ni9Ti austenitic stainless steel with BNi-2, BNi82CrSiBFe and BMn50NiCuCrCo filler metals in vacuum were investigated. It can be observed that an interdiffusion region existed between the filler metal and the base metal for the brazed joint of Ni-based filler metals. The width of the interdiffusion region was about 10 μm, and the microstructure of the brazed joint of BNi-2 filler metal was dense and free of obvious defects. In the case of the brazed joint of BMn50NiCuCrCo filler metal, there were pits, pores and crack defects in the brazing joint due to insufficient wettability of the filler metal. Crack defects can also be observed in the brazed joint of BNi82CrSiBFe filler metal. Compared with BMn50NiCuCrCo and BNi82CrSiBFe filler metals, BNi-2 filler metal is the best material for 1Cr18Ni9Ti austenitic stainless steel vacuum brazing because of its distinct weldability. PMID:28772745

High-frequency sonography of temporary and permanent dermal fillers.

PubMed

Grippaudo, Francesca Romana; Mattei, Mauro

2010-08-01

Dermal fillers are used widely; some have a permanent effect, whereas others are temporary. The aim of this study is to describe the ultrasonographic features of permanent and temporary fillers injected into patients for cosmetic purposes. Between December 2006 and April 2009, 36 subjects, aged 25-45, who had received lips or nasolabial fold filler augmentation, were enrolled for a high-frequency sonographic examination by a blinded investigator. The criteria for exclusion were a history of autoimmunity, infection, neoplastic diseases or episodes of local reactions to the injected filler. Twenty patients underwent a sonographic exam after the injection of a temporary filler (collagen or hyaluronic acid) by FRG; the rest were enrolled among patients seeking a consultation for further cosmetic reasons, but had been treated with an identifiable filler before. It was always possible to identify the filler at the site of injection. Seldom was it possible to discover a silent inflammatory reaction, otherwise unsuspected. The sonographic images differed according to the temporary or the permanent nature of the filler. Ultrasonography has proved to be a useful, non-invasive tool for the identification of the presence and type of the filler injected.

B218 Weld Filler Wire Characterization for Al-Li Alloy 2195

NASA Technical Reports Server (NTRS)

Bjorkman, Gerry; Russell, Carolyn

2000-01-01

NASA Marshall Space Flight Center, Lockheed Martin Space Systems- Michoud Operations, and McCook Metals have developed an aluminum-copper weld filler wire for fusion welding aluminum lithium alloy 2195. The aluminum-copper based weld filler wire has been identified as B218, a McCook Metals designation. B218 is the result of six years of weld filler wire development funded by NASA, Lockheed Martin, and McCook Metals. The filler wire chemistry was developed to produce enhanced 2195 weld and repair weld mechanical properties over the 4043 aluminum-silicon weld filler wire, which is currently used to weld 2195 on the Super Lightweight External Tank for the NASA Space Shuttle Program. An initial characterization was performed consisting of a repair weld evaluation using B218 and 4043 weld filler wires. The testing involved room temperature and cryogenic repair weld tensile testing along with fracture toughness testing. From the testing, B218 weld filler wire produce enhanced repair weld tensile strength, ductility, and fracture properties over 4043. B218 weld filler wire has proved to be a superior weld filler wire for welding aluminum lithium alloy 2195 over 4043.

Punctors: A Pragmatic Variable.

ERIC Educational Resources Information Center

Vincent, Diane; Sankoff, David

1992-01-01

Analysis of the distribution of punctors, a class of markers commonly classified as nervous tics, fillers, or signs of hesitation, in one corpus of French is presented. Some aspects of their conditioning are explained in terms of the interaction of etymological, discursive, syntactic, and social constraints. (Author/MSE)

The Study of the Interaction between Silica Filler and Silicone Rubber

NASA Astrophysics Data System (ADS)

Liu, Jiesheng; Gong, Xiaoqiang; Zhang, Rongtang

2018-01-01

The interaction between silica filler and silicone rubber was studied by swelling ratio, Kraus curve and crosslinking density test. The results showed that lower values of Vro/Vrf and swelling ratio in modified filler system suggests good filler-matrix interactions. The composites with silane coupling agents show higher crosslink-density compared that of untreated ones. In the light of the above statement, it can be concluded that modification of filler is the crucial factor in creating a good interaction between the filler and silicone rubber.

Myomodulation with Injectable Fillers: An Innovative Approach to Addressing Facial Muscle Movement.

PubMed

de Maio, Maurício

2018-06-01

Consideration of facial muscle dynamics is underappreciated among clinicians who provide injectable filler treatment. Injectable fillers are customarily used to fill static wrinkles, folds, and localized areas of volume loss, whereas neuromodulators are used to address excessive muscle movement. However, a more comprehensive understanding of the role of muscle function in facial appearance, taking into account biomechanical concepts such as the balance of activity among synergistic and antagonistic muscle groups, is critical to restoring facial appearance to that of a typical youthful individual with facial esthetic treatments. Failure to fully understand the effects of loss of support (due to aging or congenital structural deficiency) on muscle stability and interaction can result in inadequate or inappropriate treatment, producing an unnatural appearance. This article outlines these concepts to provide an innovative framework for an understanding of the role of muscle movement on facial appearance and presents cases that illustrate how modulation of muscle movement with injectable fillers can address structural deficiencies, rebalance abnormal muscle activity, and restore facial appearance. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Phonon dynamics in type-VIII silicon clathrates: Beyond the rattler concept

NASA Astrophysics Data System (ADS)

Norouzzadeh, Payam; Myles, Charles W.; Vashaee, Daryoosh

2017-05-01

Clathrates can form a type of guest-host solid structures that, unlike most crystalline solids, have very low thermal conductivity. It is generally thought that the guest atoms caged inside the host framework act as "rattlers" and induce lattice dynamics disorders responsible for the small thermal conductivity. We performed a systematic study of the lattice dynamical properties of type-VIII clathrates with alkali and alkaline-earth guests, i.e., X8S i46 (X =Na , K, Rb, Cs, Ca, Sr, and Ba). The energy dependent participation ratio (PR) and the atomic participation ratio of phonon modes extracted from density functional theory calculations revealed that the rattler concept is not adequate to describe the effect of fillers as they manifest strong hybridization with the framework. For the case of heavy fillers, such as Rb, Sr, Cs, and Ba, a phonon band gap was formed between the acoustic and optical branches. The calculated PR indicated that the fillers suppress the acoustic phonon modes and change the energy transport mechanism from propagative to diffusive or localized resulting in "phonon-glass" characteristics. This effect is stronger for the heavy fillers. Furthermore, in all cases, the guest insertion depressed the phonon bandwidth, reduced the Debye temperature, and reduced the phonon group velocity, all of which should lead to reduction of the thermal conductivity.

Variable Thermal-Force Bending of a Three-Layer Bar with a Compressible Filler

NASA Astrophysics Data System (ADS)

Starovoitov, E. I.; Leonenko, D. V.

2017-11-01

Deformation of a three-layer elastoplastic bar with a compressible filler in a temperature field is considered. To describe the kinematics of a pack asymmetric across its thickness, the hypothesis of broken line is accepted, according to which the Bernoulli hypothesis is true in thin bearing layers, and the Timoshenko hypothesis is valid for a filler compressible across the its thickness, with a linear approximation of displacements across the layer thickness. The work of filler in the tangential direction is taken into account. The physical stress-strain relations correspond to the theory of small elastoplastic deformations. Temperature variations are calculated from a formula obtained by averaging the thermophysical properties of layer materials across the bar thickness. Using the variational method, a system of differential equilibrium equations is derived. On the boundary, the kinematic conditions of simply supported ends of the bar are assumed. The solution of the boundary problem is reduced to the search for four functions, namely, deflections and longitudinal displacements of median surfaces of the bearing layers. An analytical solution is derived by the method of elastic solutions with the use of the Moskvitin theorem on variable loadings. Its numerical analysis is performed for the cases of continuous and local loads.

Soy-based fillers for thermoset composites

NASA Astrophysics Data System (ADS)

Watt, Paula

Considerable work has been done with bio-based fillers in thermoplastics. Wood dust has been used for decades in wood plastic composites in conjunction with recycled high HDPE and PET. In recent years rapidly renewable fillers derived from dried distillery grains and from wood have been introduced commercially for thermoset polymers. These fillers provide bio-content and weight reduction to thermoset molding compounds but issues with moisture absorption and polymerization inhibition have limited their commercial acceptance. The intent of this research was to develop a bio-based filler suitable for thermoset composites. This filler would provide a low density alternative to mined mineral filler, such as CaCO3 or clay. Composites made with these fillers would be lighter in weight, which is desirable for many markets, particularly transportation. Cost parity to the mineral fillers, on a volume basis, was desirable and the use of green chemistry principles was a key objective of the project. This work provides a basis from which further development of modified soy flours as fillers for thermoset composites will continue. Biomass has been evaluated as fillers for thermoset composites since the early 1980s but failed to gain commercial acceptance due to excessive water absorption and inhibition issues with free radical curing. Biomass, with a large percentage of carbohydrates, are very hydrophilic due to their abundance of hydroxyl groups, while biomass, high in lignin, resulted in inhibition of the free radical cure of the unsaturated styrenated polyester matrix systems. Generally protein use as a filler is not desirable due to its food value. Torrefaction has proved to be a good, cost effective, process to reduce hydrophilicity of high cellulose feedstock. Surprising, however, some levels of torrefaction were found to induce the inhibition effect of the filler. Scientific inquiry into this problem proved that aromatics form during the torrefaction process and can become problematic when threshold levels are reached. Studies to determine suitable levels and appropriate processes provided options for manufacture of suitable fillers.

Joint Workplan on Filler Investigations for DPCs.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hardin, Ernest; Brady, Patrick Vane

2017-12-01

This workplan addresses filler attributes (i.e., possible requirements), assumptions needed for analysis, selection of filler materials, testing needs, and a long-range perspective on R&D activities leading to filler demonstration and a safety basis for implementation.

Thermo-mechanical characterization of siliconized E-glass fiber/hematite particles reinforced epoxy resin hybrid composite

NASA Astrophysics Data System (ADS)

V. R., Arun prakash; Rajadurai, A.

2016-10-01

In this present work hybrid polymer (epoxy) matrix composite has been strengthened with surface modified E-glass fiber and iron(III) oxide particles with varying size. The particle sizes of 200 nm and <100 nm has been prepared by high energy ball milling and sol-gel methods respectively. To enhance better dispersion of particles and improve adhesion of fibers and fillers with epoxy matrix surface modification process has been done on both fiber and filler by an amino functional silane 3-Aminopropyltrimethoxysilane (APTMS). Crystalline and functional groups of siliconized iron(III) oxide particles were characterized by XRD and FTIR spectroscopy analysis. Fixed quantity of surface treated 15 vol% E-glass fiber was laid along with 0.5 and 1.0 vol% of iron(III) oxide particles into the matrix to fabricate hybrid composites. The composites were cured by an aliphatic hardener Triethylenetetramine (TETA). Effectiveness of surface modified particles and fibers addition into the resin matrix were revealed by mechanical testing like tensile testing, flexural testing, impact testing, inter laminar shear strength and hardness. Thermal behavior of composites was evaluated by TGA, DSC and thermal conductivity (Lee's disc). The scanning electron microscopy was employed to found shape and size of iron(III) oxide particles adhesion quality of fiber with epoxy matrix. Good dispersion of fillers in matrix was achieved with surface modifier APTMS. Tensile, flexural, impact and inter laminar shear strength of composites was improved by reinforcing surface modified fiber and filler. Thermal stability of epoxy resin was improved when surface modified fiber was reinforced along with hard hematite particles. Thermal conductivity of epoxy increased with increase of hematite content in epoxy matrix.

Safety and effectiveness of hyaluronic acid fillers in skin of color.

PubMed

Grimes, Pearl E; Thomas, Jane A; Murphy, Diane K

2009-09-01

To assess the safety and effectiveness of hyaluronic acid (HA) fillers in skin of color. Two prospective studies followed up subjects with Fitzpatrick skin phototypes of IV, V, or VI for 24 weeks after dermal filler injections. In a double-blind, randomized study, subjects were injected with one of three high concentration (24 mg/mL) HA fillers (Juvéderm Ultra, Ultra Plus, and 30) in one nasolabial fold and Zyplast collagen in the other. In an open-label, randomized study, subjects received one of three low concentration (5.5 mg/mL) HA fillers (Hylaform, Hylaform Plus, and Captique) in both nasolabial folds. A total of 160 subjects (a subset of 439 study subjects) were randomized and treated with one of the three high concentration fillers, and 119 subjects were randomized and treated with one of the three low concentration fillers. For subjects treated with the high concentration fillers there were no occurrences of hypersensitivity or hypertrophic scarring, and no increased incidence of hyperpigmentation or hypopigmentation in non-Caucasian vs. Caucasian subjects. For subjects treated with the low concentration fillers there were no occurrences of keloid formation, hypertrophic scarring, hypopigmentation, hypersensitivity, and three instances of mild hyperpigmentation. For all of the fillers the majority of subjects maintained >/=1 point improvement in nasolabial fold severity scores through 24 weeks. All of the HA fillers were well tolerated in individuals with skin of color and demonstrated effectiveness throughout the 24 week period. Furthermore, the fillers provided smooth, natural-looking wrinkle correction in darker skin types.

Effect of Filler and Heat Treatment on the Physical and Mechanical Properties of the Brazed Joint between Carbide Tip and Steel

NASA Astrophysics Data System (ADS)

Winardi, Y.; Triyono; Wijayanta, A. T.

2017-02-01

In this study, the effect of filler and heat treatment on the physical and mechanical properties of the brazed joint carbide tip and steel was investigated. Tip carbide YG6 and low carbon steel (SS400) is joining by torch brazing with two filler metals, silver, and copper filler. Heat treatment was performed in induction furnace. Microstructure and shear strength of the brazed joint have been investigated. Many silver filler layer are formed on the surface of the base metal rather then using copper filler. The highest shear strength is achieved using a silver filler metal at temperatur 725°C. The highest shear load is 18.62 kN.

Filler particle size and composite resin classification systems.

PubMed

Lang, B R; Jaarda, M; Wang, R F

1992-11-01

The currently used composite resin classification systems need review if they are to continue to serve as descriptives and quantitative parameters denoting the filler particle content of these materials. Examination of the particles in 12 composite resins using a technique of washing the filler particles from the matrix of the composite resin was presented as yet another method of grouping composites according to filler particle content. Light microscopic examination of the filler particles that remained provided a separation of the 12 materials into four easily distinguished groups based on filler particle sizes. The wear of the 12 composite resins determined in a previous study was examined in relation to the classification of the materials by the currently available systems. The wear values were also examined using the groupings of the materials according to their filler particle sizes as determined by separating the particles from the matrix by the washing technique. Grouping composites on the basis of the filler particle sizes found after washing was easily correlated with wear and supported the suggestion that composites with smaller filler particles wear less.

Functionalizable hydrogel microparticles of tunable size and stiffness for soft-tissue filler applications

PubMed Central

Chan, Ka Man Carmen; Li, Randolph H.; Chapman, Joseph W.; Trac, Eric M.; Kobler, James B.; Zeitels, Steven M.; Langer, Robert; Karajanagi, Sandeep S.

2014-01-01

Particle size, stiffness and surface functionality are important in determining the injection site, safety and efficacy of injectable soft-tissue fillers. Methods to produce soft injectable biomaterials with controlled particle characteristics are therefore desirable. Here we report a method based on suspension photopolymerization and semi-interpenetrating network (semi-IPN) to synthesize soft, functionalizable, spherical hydrogel microparticles (MP) of independently tunable size and stiffness. MP were prepared using acrylated forms of polyethylene glycol (PEG), gelatin and hyaluronic acid. Semi-IPN MP of PEG-diacrylate and PEG were used to study the effect of process parameters on particle characteristics. The process parameters were systematically varied to produce MP with size ranging from 115 to 515 μm and stiffness ranging from 190 to 1600 Pa. In vitro studies showed that the MP thus prepared were cytocompatible. The ratio and identity of the polymers used to make the semi-IPN MP were varied to control their stiffness and to introduce amine groups for potential functionalization. Slow-release polymeric particles loaded with Rhodamine or dexamethasone were incorporated in the MP as a proof-of-principle of drug incorporation and release from the MP. This work has implications in preparing injectable biomaterials of natural or synthetic polymers for applications as soft-tissue fillers. PMID:24561708

Towards development of lignin reinforced elastomeric compounds with reduced energy dissipation

NASA Astrophysics Data System (ADS)

Bahl, Kushal

This research deals with development of lignin as reinforcing filler for elastomeric compounds. Lignins are naturally abundant and cost competitive wood derivatives possessing strong mechanical properties and offering reactive functional groups on their surfaces. The presence of the functional groups imparts polarity to the lignin molecules and makes them incompatible with non-polar elastomers. Also, the large particle size of lignin does not produce desired mechanical reinforcement. The present study deals with solving the outstanding issues associated with the use of lignin as fillers for polymeric compounds. In addition, the work specifically focuses on producing rubber compounds with reduced energy dissipation via partial replacement of carbon black with lignin. The first part of this study is devoted to suppression of the polarity of lignin and achievement of compatibility with rubber matrix via modification of lignosulfonates (LS) with cyclohexylamine (CA). CA reduces the polarity of lignin via interactions originating from proton transfer and hydrogen bonding. X-ray Photoelectron Spectroscopy (XPS) confirms the attachment of CA on the surfaces of lignin. The mechanical properties of rubber compounds increase substantially along with improvement in cure properties and increase in crosslink density in the presence of LS particles modified with CA. The tensile strength and storage modulus show an increase by 45% and 41% respectively. The values of the 100% modulus and elongation at break also improve by 35% and 60% respectively. The second part of this study exploits the non-covalent interactions between lignin and carbon black (CB) for the design of novel hybrid filler particles exhibiting lower energy loss in rubber compounds. The hybrid fillers offer unique morphology consisting of coating layers of lignin on carbon black particle aggregates. It is found that such coating layers are formed due to pi-pi interactions between lignin and carbon black. Raman spectroscopy and 1H spin-lattice relaxation times confirm pi-pi interactions. The hybrid fillers offer reduction of networking of carbon black particles and viscoelastic dissipation in rubber compounds without sacrificing the mechanical performance. The third part of this study evaluates the performance of polybutadiene- g-polypentafluorostyrene (PB-g-PPFS) as a coupling agent for promotion of interactions between lignin and rubber and to achieve better overall reinforcing performance. The PB domains of PB-g-PPFS are compatible with styrene-butadiene rubber (SBR) while the PPFS segments engage in arene-perfluoroarene interactions with lignin. These interactions are confirmed via UV-vis spectroscopy data. The efficacy of PB-g-PPFS as a coupling agent is evaluated for compounds filled with lignin and lignin/carbon black hybrid fillers. The results show that the addition of PB-g-PPFS improves the tensile strength by 33% and reduces the viscoelastic loss in filled SBR compounds by improving filler dispersion. The results presented in this thesis demonstrate that the approaches of surface modification, exploitation of non-covalent interactions, and the use of coupling agents are effective in solving the impending issues associated with the use of lignin, the second most abundant bio-derived material, as effective reinforcing filler for polymer compounds.

Understanding the Percolation Characteristics of Nonlinear Composite Dielectrics

PubMed Central

Yang, Xiao; Hu, Jun; Chen, Shuiming; He, Jinliang

2016-01-01

Nonlinear composite dielectrics can function as smart materials for stress control and field grading in all fields of electrical insulations. The percolation process is a significant issue of composite dielectrics. However, the classic percolation theory mainly deals with traditional composites in which the electrical parameters of both insulation matrix and conducting fillers are independent of the applied electric field. This paper measured the nonlinear V-I characteristics of ZnO microvaristors/silicone rubber composites with several filler concentrations around an estimated percolation threshold. For the comparison with the experiment, a new microstructural model is proposed to simulate the nonlinear conducting behavior of the composite dielectrics modified by metal oxide fillers, which is based on the Voronoi network and considers the breakdown feature of the insulation matrix for near percolated composites. Through both experiment and simulation, the interior conducting mechanism and percolation process of the nonlinear composites were presented and a specific percolation threshold was determined as 33%. This work has provided a solution to better understand the characteristics of nonlinear composite dielectrics. PMID:27476998

Understanding the Percolation Characteristics of Nonlinear Composite Dielectrics

NASA Astrophysics Data System (ADS)

Yang, Xiao; Hu, Jun; Chen, Shuiming; He, Jinliang

2016-08-01

Nonlinear composite dielectrics can function as smart materials for stress control and field grading in all fields of electrical insulations. The percolation process is a significant issue of composite dielectrics. However, the classic percolation theory mainly deals with traditional composites in which the electrical parameters of both insulation matrix and conducting fillers are independent of the applied electric field. This paper measured the nonlinear V-I characteristics of ZnO microvaristors/silicone rubber composites with several filler concentrations around an estimated percolation threshold. For the comparison with the experiment, a new microstructural model is proposed to simulate the nonlinear conducting behavior of the composite dielectrics modified by metal oxide fillers, which is based on the Voronoi network and considers the breakdown feature of the insulation matrix for near percolated composites. Through both experiment and simulation, the interior conducting mechanism and percolation process of the nonlinear composites were presented and a specific percolation threshold was determined as 33%. This work has provided a solution to better understand the characteristics of nonlinear composite dielectrics.

Effects of filler type and content on mechanical properties of photopolymerizable composites measured across two-dimensional combinatorial arrays.

PubMed

Lin-Gibson, Sheng; Sung, Lipiin; Forster, Aaron M; Hu, Haiqing; Cheng, Yajun; Lin, Nancy J

2009-07-01

Multicomponent formulations coupled with complex processing conditions govern the final properties of photopolymerizable dental composites. In this study, a single test substrate was fabricated to support multiple formulations with a gradient in degree of conversion (DC), allowing the evaluation of multiple processing conditions and formulations on one specimen. Mechanical properties and damage response were evaluated as a function of filler type/content and irradiation. DC, surface roughness, modulus, hardness, scratch deformation and cytotoxicity were quantified using techniques including near-infrared spectroscopy, laser confocal scanning microscopy, depth-sensing indentation, scratch testing and cell viability. Scratch parameters (depth, width, percent recovery) were correlated to composite modulus and hardness. Total filler content, nanofiller and irradiation time/intensity all affected the final properties, with the dominant factor for improved properties being a higher DC. This combinatorial platform accelerates the screening of dental composites through the direct comparison of properties and processing conditions across the same sample.

Microstructural Evolution of Inconel 625 and Inconel 686CPT Weld Metal for Clad Carbon Steel Linepipe Joints: A Comparator Study

NASA Astrophysics Data System (ADS)

Maltin, Charles A.; Galloway, Alexander M.; Mweemba, Martin

2014-07-01

Microstructural evolution of Inconel 625 and Inconel 686CPT filler metals, used for the fusion welding of clad carbon steel linepipe, has been investigated and compared. The effects of iron dilution from the linepipe parent material on the elemental segregation potential of the filler metal chemistry have been considered. The results obtained provide significant evidence to support the view that, in Inconel 686CPT weld metal, the segregation of tungsten is a function of the level of iron dilution from the parent material. The data presented indicate that the incoherent phase precipitated in the Inconel 686CPT weld metal has a morphology that is dependent on tungsten enrichment and, therefore, iron dilution. Furthermore, in the same weld metal, a continuous network of finer precipitates was observed. The Charpy impact toughness of each filler metal was evaluated, and the results highlighted the superior impact toughness of the Inconel 625 weld metal over that of Inconel 686CPT.

Mesoporous Silica Gel-Based Mixed Matrix Membranes for Improving Mass Transfer in Forward Osmosis: Effect of Pore Size of Filler.

PubMed

Lee, Jian-Yuan; Wang, Yining; Tang, Chuyang Y; Huo, Fengwei

2015-11-23

The efficiency of forward osmosis (FO) process is generally limited by the internal concentration polarization (ICP) of solutes inside its porous substrate. In this study, mesoporous silica gel (SG) with nominal pore size ranging from 4-30 nm was used as fillers to prepare SG-based mixed matrix substrates. The resulting mixed matrix membranes had significantly reduced structural parameter and enhanced membrane water permeability as a result of the improved surface porosity of the substrates. An optimal filler pore size of ~9 nm was observed. This is in direct contrast to the case of thin film nanocomposite membranes, where microporous nanoparticle fillers are loaded to the membrane rejection layer and are designed in such a way that these fillers are able to retain solutes while allowing water to permeate through them. In the current study, the mesoporous fillers are designed as channels to both water and solute molecules. FO performance was enhanced at increasing filler pore size up to 9 nm due to the lower hydraulic resistance of the fillers. Nevertheless, further increasing filler pore size to 30 nm was accompanied with reduced FO efficiency, which can be attributed to the intrusion of polymer dope into the filler pores.

Calculating permittivity of semi-conductor fillers in composites based on simplified effective medium approximation models

NASA Astrophysics Data System (ADS)

Feng, Yefeng; Wu, Qin; Hu, Jianbing; Xu, Zhichao; Peng, Cheng; Xia, Zexu

2018-03-01

Interface induced polarization has a significant impact on permittivity of 0–3 type polymer composites with Si based semi-conducting fillers. Polarity of Si based filler, polarity of polymer matrix and grain size of filler are closely connected with induced polarization and permittivity of composites. However, unlike 2–2 type composites, the real permittivity of Si based fillers in 0–3 type composites could be not directly measured. Therefore, achieving the theoretical permittivity of fillers in 0–3 composites through effective medium approximation (EMA) models should be very necessary. In this work, the real permittivity results of Si based semi-conducting fillers in ten different 0–3 polymer composite systems were calculated by linear fitting of simplified EMA models, based on particularity of reported parameters in those composites. The results further confirmed the proposed interface induced polarization. The results further verified significant influences of filler polarity, polymer polarity and filler size on induced polarization and permittivity of composites as well. High self-consistency was gained between present modelling and prior measuring. This work might offer a facile and effective route to achieve the difficultly measured dielectric performances of discrete filler phase in some special polymer based composite systems.

Mesoporous Silica Gel–Based Mixed Matrix Membranes for Improving Mass Transfer in Forward Osmosis: Effect of Pore Size of Filler

PubMed Central

Lee, Jian-Yuan; Wang, Yining; Tang, Chuyang Y.; Huo, Fengwei

2015-01-01

The efficiency of forward osmosis (FO) process is generally limited by the internal concentration polarization (ICP) of solutes inside its porous substrate. In this study, mesoporous silica gel (SG) with nominal pore size ranging from 4–30 nm was used as fillers to prepare SG-based mixed matrix substrates. The resulting mixed matrix membranes had significantly reduced structural parameter and enhanced membrane water permeability as a result of the improved surface porosity of the substrates. An optimal filler pore size of ~9 nm was observed. This is in direct contrast to the case of thin film nanocomposite membranes, where microporous nanoparticle fillers are loaded to the membrane rejection layer and are designed in such a way that these fillers are able to retain solutes while allowing water to permeate through them. In the current study, the mesoporous fillers are designed as channels to both water and solute molecules. FO performance was enhanced at increasing filler pore size up to 9 nm due to the lower hydraulic resistance of the fillers. Nevertheless, further increasing filler pore size to 30 nm was accompanied with reduced FO efficiency, which can be attributed to the intrusion of polymer dope into the filler pores. PMID:26592565

Efficient CO2 capture by functionalized graphene oxide nanosheets as fillers to fabricate multi-permselective mixed matrix membranes.

PubMed

Li, Xueqin; Cheng, Youdong; Zhang, Haiyang; Wang, Shaofei; Jiang, Zhongyi; Guo, Ruili; Wu, Hong

2015-03-11

A novel multi-permselective mixed matrix membrane (MP-MMM) is developed by incorporating versatile fillers functionalized with ethylene oxide (EO) groups and an amine carrier into a polymer matrix. The as-prepared MP-MMMs can separate CO2 efficiently because of the simultaneous enhancement of diffusivity selectivity, solubility selectivity, and reactivity selectivity. To be specific, MP-MMMs were fabricated by incorporating polyethylene glycol- and polyethylenimine-functionalized graphene oxide nanosheets (PEG-PEI-GO) into a commercial low-cost Pebax matrix. The PEG-PEI-GO plays multiple roles in enhancing membrane performance. First, the high-aspect ratio GO nanosheets in a polymer matrix increase the length of the tortuous path of gas diffusion and generate a rigidified interface between the polymer matrix and fillers, enhancing the diffusivity selectivity. Second, PEG consisting of EO groups has excellent affinity for CO2 to enhance the solubility selectivity. Third, PEI with abundant primary, secondary, and tertiary amine groups reacts reversibly with CO2 to enhance reactivity selectivity. Thus, the as-prepared MP-MMMs exhibit excellent CO2 permeability and CO2/gas selectivity. The MP-MMM doped with 10 wt % PEG-PEI-GO displays optimal gas separation performance with a CO2 permeability of 1330 Barrer, a CO2/CH4 selectivity of 45, and a CO2/N2 selectivity of 120, surpassing the upper bound lines of the Robeson study of 2008 (1 Barrer = 10(-10) cm(3) (STP) cm(-2) s(-1) cm(-1) Hg).

A systematic and mechanistic evaluation of aspartic acid as filler for directly compressed tablets containing trimethoprim and trimethoprim aspartate.

PubMed

ElShaer, Amr; Hanson, Peter; Mohammed, Afzal R

2013-04-01

The generally accepted paradigm of 'inert' and 'mono functional' excipient in dosage form has been recently challenged with the development of individual excipients capable of exhibiting multiple functions (e.g. binder-disintegrants, surfactant which affect P-gp function). The proposed study has been designed within the realm of multifunctionality and is the first and novel investigation towards evaluation of aspartic acid as a filler and disintegration enhancing agent for the delivery of biopharmaceutical class IV model drug trimethoprim. The study investigated powder characteristics using angle of repose, laser diffractometry and scanning electron microscopy (SEM). The prepared tablets were characterised using Heckel analysis, disintegration time and tensile strength measurements. Although Heckel analysis revealed that both TMP and TMP aspartate salt have high elasticity, the salt form produced a stronger compact which was attributed to the formation of agglomerates. Aspartic acid was found to have high plasticity, but its incorporation into the formulations was found to have a negative impact on the compaction properties of TMP and its salt. Surface morphology investigations showed that mechanical interlocking plays a vital role in binding TMP crystals together during compaction, while the small particle size of TMP aspartate agglomerates was found to have significant impact on the tensile strength of the tablets. The study concluded that aspartic acid can be employed as filler and disintegrant and that compactability within tablets was independent of the surface charge of the excipients. Copyright © 2012 Elsevier B.V. All rights reserved.

Morphological and electrical properties of epoxy-based composites reinforced with exfoliated graphite

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lamberti, Patrizia; Spinelli, Giovanni, E-mail: gspinelli@unisa.it; Tucci, Vincenzo

An experimental study has been carried out to prepare and characterize epoxy/amine-based composites filled with different percentages of partially exfoliated graphite (i.e. pEG) particles having an exfoliation degree of 56% in order to analyze the effect of the filler amounts on the electrical properties of the resulting nanocomposites. Moreover, in order to fully investigate the direct relationship between the physical properties of the employed filler and the results of the electrical characterization, a structural and morphological characterization of the pEG samples is carried out by means of various type of analysis such as X-ray diffraction patterns, micro-Raman and Scanning Electronmore » Microscopy (SEM) images. The DC electrical characterization reveals a percolation thresholds (EPT) that falls in the range [2–3] wt% and an electrical conductivity of about 0.66 S/m at the highest filler loading (6.5 wt%). From the analysis of the percolative curve it is possible to derive the percolation law parameters and in particular the critical exponent t, whose value (i.e. 1.2) reflects an effective 2D organization of the percolating structure consistent with the type of filler used (2-dimensional). Finally, an extensive analysis concerning the electrical properties in the frequency domain has been carried out in order to evaluate the effectiveness of pEG-loaded composites in terms of electromagnetic interference compatibility (EMC) and their applicability as radar absorbers materials (RAMs).« less

Infectious complications of Bio-Alcamid filler used for HIV-related facial lipoatrophy.

PubMed

Nadarajah, Jeya T; Collins, Micaela; Raboud, Janet; Su, DeSheng; Rao, Kavya; Loutfy, Mona R; Walmsley, Sharon

2012-12-01

Human immunodeficiency virus (HIV)-related facial lipoatrophy is a devastating adverse effect of antiretroviral therapy. At this time, the most viable treatment option is cosmetic surgery with synthetic fillers. Bio-Alcamid has many advantages over other fillers, and has become widely used. The objective of this study was to determine the incidence rate of infectious complications associated with Bio-Alcamid facial filler in patients with HIV-related facial lipoatrophy (FLA). This retrospective study identified patients who had received treatment with Bio-Alcamid, and reviewed their long-term outcomes. Two hundred sixty-seven patients with Bio-Alcamid were reviewed. Infectious complications were documented in 56 (19%) patients. The incidence rate of infection was 0.07 per patient-year of follow-up. Among patients with infections, the median time from first Bio-Alcamid treatment to infection was 32 months (interquartile range, 21-42). We did not find an association between the development of infection and the level of immune suppression by HIV. Surgical drainage in addition to antibiotics was required for the majority of patients. Potential risk factors for infection include severity of FLA and a preceding history of facial manipulation, including Bio-Alcamid touch-up treatments, cosmetic surgery, facial trauma, and dental work. Bio-Alcamid treatment of HIV-related FLA was associated with a high rate of infectious complications, often presenting years after treatment. Antibiotic prophylaxis should be considered in patients with Bio-Alcamid prior to dental work or facial manipulation.

In vitro studies of degradation and bioactivity of aliphatic polyester composites

NASA Astrophysics Data System (ADS)

Chouzouri, Georgia

In spite of numerous publications on the potential use of combinations of aliphatic polyester composites containing bioactive fillers for bone regeneration, little information exists on the combined in vitro mechanisms involving simultaneously diffusion for polymer degradation and bioactivity through nucleation and growth of apatite in simulated body fluid (SBF) solution. The objective of this study is to contribute to the understanding of the fundamentals in designing non-porous, solid materials for bone regeneration, from experimental data along with their engineering interpretation. Bioactivity, in terms of apatite growth, was assessed through several experimental methods such as scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), X-ray-diffraction (XRD) and changes in ion concentration. In the case of the six neat fillers evaluated, the filler shape, form and chemical structure showed significant differences in bioactivity response. Bioglass and calcium silicate fillers showed faster nucleation and growth rates in the screening experiments. Composites at 30% by weight filler were prepared by solution and/or melt mixing. Polycaprolactone (PCL) composites containing five different fillers were evaluated. Solution processed PCL/calcium silicate (CS) samples showed faster bioactivity, as determined by apatite growth, compared to melt mixed samples. The onset time for bioactivity was different for all PCL composites. The limited bioactivity in the PCL composites over longer periods of time could be attributed to the PCL hydrophobicity leading to a slow polymer degradation rate, and also to the lack of SBF replenishment. For both polylactic acid (PLA) composites containing CS and bioglass, significant growth was observed after one week and in the case of CS was still evident after four weeks immersion. However, at prolonged time periods no further bioactivity was observed, although ion release results indicated a faster release rate that would eventually lead to a faster polymer degradation and possibly continuing bioactivity. The presence of silicate fillers enhanced the hydrolytic degradation rate of both PCL and PLA as shown from kinetic data calculations based on molecular weight measurements. Unfilled PLA samples showed significant embrittlement after two weeks immersion, whereas for the CS filled system more significant changes could be observed in the compressive strength and modulus after the same time period. Experimental data were also fitted into an equation proposed to calculate erosion number; in the case of unfilled PLA predictions were found to agree with literature results suggesting bulk erosion. By assuming impermeable, randomly dispersed glass flakes, water transport in a composite system, prior to significant polymer degradation could be modeled. However, modeling of transport in the case of the composite consisting of a degrading polymer and a reactive decaying filler was challenging, particularly in the case of directional bioactive reinforcements, due to the occurrence of simultaneous time dependent diffusion phenomena that altered the integrity of the sample.

Microscopic and ultrastructural evidences in human skin following calcium hydroxylapatite filler treatment.

PubMed

Zerbinati, Nicola; D'Este, Edoardo; Parodi, Pier Camillo; Calligaro, Alberto

2017-07-01

This study uses light and electron microscopes to gain a better knowledge of the interactions of calcium hydroxylapatite filler with the connective tissue of the skin and the modifications of the human deep dermis, after 2 months of treatment. Some morphological evidences of this observational study of filler treated tissue support-specific mechanism involved in the structural modifications of both filler microspherules and cells of the connective tissue. They demonstrate the absence of any immunological reaction and show that the used filler is modified very slowly over time by the action of cells of the connective tissue closely related to the filler without any activity of phagocytosis. Furthermore, associated with the modifications of the filler, evidences of stimulatory effects on dermal fibroblasts are reported.

Effect of monopolar radiofrequency treatment over soft-tissue fillers in an animal model: part 2.

PubMed

Shumaker, Peter R; England, Laura J; Dover, Jeffrey S; Ross, E Victor; Harford, Robert; Derienzo, Damian; Bogle, Melissa; Uebelhoer, Nathan; Jacoby, Mark; Pope, Karl

2006-03-01

Monopolar radiofrequency (RF) treatment is used by physicians to heat skin and promote tissue tightening and contouring. Cosmetic fillers are used to soften deep facial lines and wrinkles. Patients who have had dermal fillers implanted may also benefit from or are candidates for monopolar RF skin tightening. This study examined the effect of RF treatment on various dermal filler substances. This is the second part of a two-part study. A juvenile farm pig was injected with dermal fillers including cross-linked human collagen (Cosmoplast), polylactic acid (PLA) (Sculptra), liquid injectable silicone (Silikon 1000), calcium hydroxylapatite (CaHA) (Radiesse), and hyaluronic acid (Restylane). Skin injected with dermal fillers was RF-treated using a 1.5-cm2 treatment tip and treatment levels typically used in the clinical setting. Fillers were examined histologically 5 days, 2 weeks, or 1 month after treatment. Histological specimens were scored for inflammatory response, foreign body response, and fibrosis in order to assess the effect of treatment on early filler processes, such as inflammation and encapsulation. Each filler substance produced a characteristic inflammatory response. No immediate thermal effect of RF treatment was observed histologically. RF treatment resulted in statistically significant increases in the inflammatory, foreign body, and fibrotic responses associated with the filler substances. Monopolar RF treatment levels that are typically used in the clinical setting were employed in this animal study. RF treatment resulted in measurable and statistically significant histological changes associated with the various filler materials. Additional clinical and histological studies are required to determine the optimal timing of monopolar RF treatment and filler placement for maximal potential aesthetic outcome. 2006 Wiley-Liss, Inc.

Evaluation of Different Mineral Filler Aggregates for Asphalt Mixtures

NASA Astrophysics Data System (ADS)

Wasilewska, Marta; Małaszkiewicz, Dorota; Ignatiuk, Natalia

2017-10-01

Mineral filler aggregates play an important role in asphalt mixtures because they fill voids in paving mix and improve the cohesion of asphalt binder. Limestone powder containing over 90% of CaCO3 is the most frequently used type of filler. Waste material from the production of coarse aggregate can be successfully used as a mineral filler aggregate for hot asphalt concrete mixtures as the limestone powder replacement. This paper presents the experimental results of selected properties of filler aggregates which were obtained from rocks with different mineral composition and origin. Five types of rocks were used as a source of the mineral filler aggregate: granite, gabbro, trachybasalt, quartz sandstone and rocks from postglacial deposits. Limestone filler was used in this study as the reference material. The following tests were performed: grading (air jet sieving), quality of fines according to methylene blue test, water content by drying in a ventilated oven, particle density using pyknometer method, Delta ring and ball test, Bitumen Number, fineness determined as Blaine specific surface area. Mineral filler aggregates showed significant differences when they were mixed with bitumen and stiffening effect in Delta ring and ball test was evaluated. The highest values were achieved when gabbro and granite fillers were used. Additionally, Scanning Electron Microscopy (SEM) analysis of grain shape and size was carried out. Significant differences in grain size and shape were observed. The highest non-homogeneity in size was determined for quartz sandstone, gabbro and granite filler. Their Blaine specific surface area was lower than 2800 cm2/g, while for limestone and postglacial fillers with regular and round grains it exceeded 3000 cm2/g. All examined mineral filler aggregates met requirements of Polish National Specification WT-1: 2014 and could be used in asphalt mixtures.

Novel percolation phenomena and mechanism of strengthening elastomers by nanofillers.

PubMed

Wang, Zhenhua; Liu, Jun; Wu, Sizhu; Wang, Wenchuan; Zhang, Liqun

2010-03-28

Nano-strengthening by employing nanoparticles is necessary for high-efficiency strengthening of elastomers, which has already been validated by numerous researches and industrial applications, but the underlying mechanism is still an open challenge. In this work, we mainly focus our attention on studying the variation of the tensile strength of nanofilled elastomers by gradually increasing the filler content, within a low loading range. Interestingly, the percolation phenomenon is observed in the relationship between the tensile strength and the filler loading, which shares some similarities with the percolation phenomenon occurring in rubber toughened plastics. That is, as the loading of nanofillers (carbon black, zinc oxide) increases, the tensile strength of rubber nanocomposites (SBR, EPDM) increases slowly at first, then increases abruptly and finally levels off. Meanwhile, the bigger the particle size, the higher the filler content at the percolation point, and the lower the corresponding tensile strength of rubber nanocomposites. The concept of a critical particle-particle distance (CPD) is proposed to explain the observed percolation phenomenon. It is suggested that rubber strengthening through nanoparticles is attributed to the formation of stretched straight polymer chains between neighbor particles, induced by the slippage of adsorbed polymer chains on the filler surface during tension. Meanwhile, the factors to govern this CPD and the critical minimum particle size (CMPS) figured out in this work are both discussed and analyzed in detail. Within the framework of this percolation phenomenon, this paper also clearly answers two important and intriguing issues: (1) why is it necessary and essential to strengthen elastomers through nanofillers; (2) why does it need enough loading of nanofillers to effectively strengthen elastomers. Moreover, on the basis of the percolation phenomenon, we give out some guidance for reinforcement design of rubbery materials: the interfacial interactions between rubber and fillers cannot be complete chemical bonding, and partial physical absorption of macromolecular chains on the filler surface is necessary, otherwise the formation of stretched straight chains would be seriously hindered. There should exist such an optimum crosslinking density for a certain filler reinforced rubber system, and as well an optimum filler loading for rubber strengthening. Additionally, the different percolation behaviors of Young's modulus, the tensile strength and the electrical conductivity are compared and analyzed in our work. Lastly, molecular simulation indicates that it is not possible to strengthen glassy or hard polymer matrices by incorporating spherical nanoparticles. In general, by providing substantial experimental data and detailed analyses, this work is believed to promote the fundamental understanding of rubber reinforcement, as well provide better guidance for the design of high-performance and multi-functional rubber nanocomposites.

Chitosan solutions as injectable systems for dermal filler applications: Rheological characterization and biological evidence.

PubMed

Halimi, C; Montembault, A; Guerry, A; Delair, T; Viguier, E; Fulchiron, R; David, L

2015-01-01

A new generation of dermal filler for wrinkle filler based on chitosan was compared to current hyaluronic acid-based dermal fillers by using a new rheological performance criterion based on viscosity during injection related to Newtonian viscosity. In addition an in vivo evaluation was performed for preclinical evidence of chitosan use as dermal filler. In this way, biocompatibility and dermis reconstruction was evaluated on a pig model.

Effect of molecular weight of hyaluronic acid (HA) on viscoelasticity and particle texturing feel of HA dermal biphasic fillers.

PubMed

Chun, Cheolbyong; Lee, Deuk Yong; Kim, Jin-Tae; Kwon, Mi-Kyung; Kim, Young-Zu; Kim, Seok-Soon

2016-01-01

Hyaluronic acid (HA) dermal biphasic fillers are synthesized for their efficacy in correcting aesthetic defects such as wrinkles, scars and facial contouring defects. The fillers consist of crosslinked HA microspheres suspended in a noncrosslinked HA. To extend the duration of HAs within the dermis and obtain the particle texturing feel, HAs are crosslinked to obtain the suitable mechanical properties. Hyaluronic acid (HA) dermal biphasic fillers are prepared by mixing the crosslinked HA microspheres and the noncrosslinked HAs. The elastic modulus of the fillers increased with raising the volume fraction of the microspheres. The mechanical properties and the particle texturing feel of the fillers made from crosslinked HA (1058 kDa) microspheres suspended in noncrosslinked HA (1368 kDa) are successfully achieved, which are adequate for the fillers. Dermal biphasic HA fillers made from 1058 kDa exhibit suitable elastic moduli (211 to 420 Pa) and particle texturing feel (scale 7 ~ 9).

Orbiter Gap Filler Bending Model for Re-entry

NASA Technical Reports Server (NTRS)

Campbell, Charles H.

2007-01-01

Pressure loads on a protruding gap filler during an Orbiter reentry are investigated to evaluate the likelihood of extraction due to pressure loads, and to ascertain how much bending will be induced by re-entry pressure loads. Oblique shock wave theory is utilized to develop a representation of the pressure loads induced on a gap filler for the ISSHVFW trajectory, representative of a heavy weight ISS return. A free body diagram is utilized to react the forces induced by the pressure forces. Preliminary results developed using these methods demonstrate that pressure loads, alone, are not likely causes of gap filler extraction during reentry. Assessment of the amount a gap filler will bend over is presented. Implications of gap filler bending during re-entry include possible mitigation of early boundary layer transition concerns, uncertainty in ground based measurement of protruding gap fillers from historical Orbiter flight history, and uncertainty in the use of Orbiter gap fillers for boundary layer prediction calibration. Authors will be added to the author list as appropriate.

Efficacy and durability of hyaluronic acid fillers for malar enhancement: A prospective, randomized, split-face clinical controlled trial.

PubMed

Jeong, Ki Heon; Gwak, Min Jae; Moon, Sung Kyung; Lee, Sang Jun; Shin, Min Kyung

2018-06-01

Various hyaluronic acid fillers can be used for facial attenuation and rejuvenation. The efficacy and durability of hyaluronic acid fillers are of major concern to dermatologists and patients. This study aimed to evaluate three-dimensional morphology, tissue distribution, and changes in volume after injection of two different hyaluronic acid fillers. Ten Korean women were enrolled in this study. Each subject was injected with monophasic hyaluronic acid filler in one malar area and biphasic filler in the other. Clinical outcome was measured before and after injection, and after 2, 4, 6, 8, 12, and 24 weeks, using the Global Aesthetic Improvement Scale, photographs and Moire's topography. Facial magnetic resonance imaging (MRI) was performed twice over six months. Both products showed good results after injection and demonstrated good durability over time. MRI was a useful modality for assessing tissue distribution and volume changes. The effects and durability after injection of monophasic hyaluronic acid filler and biphasic hyaluronic acid filler are generally comparable.

A method for predicting optimized processing parameters for surfacing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dupont, J.N.; Marder, A.R.

1994-12-31

Welding is used extensively for surfacing applications. To operate a surfacing process efficiently, the variables must be optimized to produce low levels of dilution with the substrate while maintaining high deposition rates. An equation for dilution in terms of the welding variables, thermal efficiency factors, and thermophysical properties of the overlay and substrate was developed by balancing energy and mass terms across the welding arc. To test the validity of the resultant dilution equation, the PAW, GTAW, GMAW, and SAW processes were used to deposit austenitic stainless steel onto carbon steel over a wide range of parameters. Arc efficiency measurementsmore » were conducted using a Seebeck arc welding calorimeter. Melting efficiency was determined based on knowledge of the arc efficiency. Dilution was determined for each set of processing parameters using a quantitative image analysis system. The pertinent equations indicate dilution is a function of arc power (corrected for arc efficiency), filler metal feed rate, melting efficiency, and thermophysical properties of the overlay and substrate. With the aid of the dilution equation, the effect of processing parameters on dilution is presented by a new processing diagram. A new method is proposed for determining dilution from welding variables. Dilution is shown to depend on the arc power, filler metal feed rate, arc and melting efficiency, and the thermophysical properties of the overlay and substrate. Calculated dilution levels were compared with measured values over a large range of processing parameters and good agreement was obtained. The results have been applied to generate a processing diagram which can be used to: (1) predict the maximum deposition rate for a given arc power while maintaining adequate fusion with the substrate, and (2) predict the resultant level of dilution with the substrate.« less

Characteristics of nitrogen removal and microbial community in biofilm system via combination of pretreated lignocellulosic carriers and various conventional fillers.

PubMed

Zhao, Jing; Feng, Lijuan; Dai, Jincheng; Yang, Guangfeng; Mu, Jun

2017-12-01

Each kind of conventional plastic filler (polyurethane filler, SPR-1 suspension filler, TA-II elastic filler and sphere filler) coupled with alkaline pretreated corncob (A.H.corncob) was applied in each bioreactor system for treating polluted water with nitrate and organics. Results demonstrated that addition of A.H.corncob could achieve simultaneous removal of nitrogen and organics, and coupling of SPR-1 suspension filler with A.H.corncob (R 2 ) had the best performance. In coupling system of R 2 , the total nitrogen (TN) removal rate improved from below 10% to 55.92 ± 18.27% with effluent COD Mn concentration maintaining at a low level of 2.67 ± 0.44 mg L -1 . Microbial analysis of combined filler system demonstrated that conventional plastic filler mainly accumulated non-solid-phase denitrifiers for both nitrate and organics removal including genera Salipiger, Enterobacteriaceae etc. while A.H.corncob carrier was stronghold of solid-phase denitrifiers (Runella, etc.) directly using lignocellulosic materials as carbon source and fermentative bacteria (Coprococcus, etc.) for supplementing available carbon sources for denitrifiers in the system, which were integrated to achieve simultaneous removal of nitrate and organics.

Influence of filler loading on the two-body wear of a dental composite.

PubMed

Hu, X; Marquis, P M; Shortall, A C

2003-07-01

The purpose of the study was to explore the fundamental wear behaviour of a dental composite with different filler loadings under two-body wear conditions. The parent resin and filler components were mixed according to different weight ratios to produce experimental composites with filler loadings ranging from 20 to 87.5% by weight. A two-body wear test was conducted on the experimental composites using a wear-testing machine. The machine was designed to simulate the impact of the direct cyclic masticatory loading that occurs in the occlusal contact area in vivo. The results showed that there was little increase in the rate of wear with filler loadings below 60 wt%, but a sharp increase between 80 and 87.5 wt% in filler loading. Wide striations and bulk loss of material were apparent on the wear surfaces at higher filler loadings. Coefficients of friction increased with filler loading and followed the increase in rate of wear loss closely. It was concluded that, under two-body wear conditions, addition of high levels of filler particles into the resin matrix could reduce the wear resistance of dental composites. This finding may help when designing future dental composites for use in particular clinical settings.

Mechanical Properties of Epoxy Resin Mortar with Sand Washing Waste as Filler.

PubMed

Yemam, Dinberu Molla; Kim, Baek-Joong; Moon, Ji-Yeon; Yi, Chongku

2017-02-28

The objective of this study was to investigate the potential use of sand washing waste as filler for epoxy resin mortar. The mechanical properties of four series of mortars containing epoxy binder at 10, 15, 20, and 25 wt. % mixed with sand blended with sand washing waste filler in the range of 0-20 wt. % were examined. The compressive and flexural strength increased with the increase in epoxy and filler content; however, above epoxy 20 wt. %, slight change was seen in strength due to increase in epoxy and filler content. Modulus of elasticity also linearly increased with the increase in filler content, but the use of epoxy content beyond 20 wt. % decreased the modulus of elasticity of the mortar. For epoxy content at 10 wt. %, poor bond strength lower than 0.8 MPa was observed, and adding filler at 20 wt. % adversely affected the bond strength, in contrast to the mortars containing epoxy at 15, 20, 25 wt. %. The results indicate that the sand washing waste can be used as potential filler for epoxy resin mortar to obtain better mechanical properties by adding the optimum level of sand washing waste filler.

Mechanical Properties of Epoxy Resin Mortar with Sand Washing Waste as Filler

PubMed Central

Yemam, Dinberu Molla; Kim, Baek-Joong; Moon, Ji-Yeon; Yi, Chongku

2017-01-01

The objective of this study was to investigate the potential use of sand washing waste as filler for epoxy resin mortar. The mechanical properties of four series of mortars containing epoxy binder at 10, 15, 20, and 25 wt. % mixed with sand blended with sand washing waste filler in the range of 0–20 wt. % were examined. The compressive and flexural strength increased with the increase in epoxy and filler content; however, above epoxy 20 wt. %, slight change was seen in strength due to increase in epoxy and filler content. Modulus of elasticity also linearly increased with the increase in filler content, but the use of epoxy content beyond 20 wt. % decreased the modulus of elasticity of the mortar. For epoxy content at 10 wt. %, poor bond strength lower than 0.8 MPa was observed, and adding filler at 20 wt. % adversely affected the bond strength, in contrast to the mortars containing epoxy at 15, 20, 25 wt. %. The results indicate that the sand washing waste can be used as potential filler for epoxy resin mortar to obtain better mechanical properties by adding the optimum level of sand washing waste filler. PMID:28772603

East Europe Report, Economic and Industrial Affairs, Long-Term Program for Production Quality

DTIC Science & Technology

1984-05-29

increase the production of confectionery goods and snacks with a lower sugar content but enriched with natural juice and vegetable fillers, vegetable and...variety of con- struction materials and items by organizing the production of gasconcrete, extruded asbestos cement walls, gypsum board, heat, water

Analysis of Voltage and Current Signal Processing in a Li-ion Battery Management System

DTIC Science & Technology

2010-09-01

SUBJECT TERMS Pulsed Power, Charger, Buck Converter, Field Programmable Gate Array (FPGA), Lithium - ion Batteries 16. PRICE CODE 17. SECURITY...Congressional Research Service. July 31, 2000. [3] F. E. Filler, “A Pulsed Power System Design Using Lithium - ion Batteries and One Charger per Battery

Production, characterization, and modeling of mineral filled polypropylene filaments

NASA Astrophysics Data System (ADS)

George, Brian Robert

1999-11-01

This research produced mineral filled polypropylene filaments using a variety of fillers, characterized these filaments, and attempted to model their mechanical properties with current composite models. Also, these filaments were compared with bone to determine if they are suitable for modeling the mechanical properties of bone. Fillers used consist of wollastonite, talc, calcium carbonate, titanium dioxide, and hydroxyapatite. Fillers and polypropylene chips were combined and extruded into rods with the use of a mixer. The rods were chipped up and then formed into filaments through melt extrusion utilizing a piston extruder. Filaments with volume fractions of filler of 0.05, 0.10, 0.15, and 0.20 were produced. Additionally, some methods of trying to improve the properties of these filaments were attempted, but did not result in any significant property improvements. The fillers and filaments were visually characterized with a scanning electron microscope. Cross-sections, filament outer surfaces, fracture surfaces, and longitudinal cut open surfaces were viewed in this manner. Those filaments with anisotropic filler had some oriented filler particles, while all filaments suffered from poor adhesion between the polypropylene and the filler as well as agglomerations of filler particles. Twenty specimens of each filament were tensile tested and the average tenacity, strain, and modulus were calculated. Filaments containing talc, talc and wollastonite, titanium dioxide, or hydroxyapatite suffered from a drastic transition from ductile to brittle with the addition of 0.05 volume fraction of filler. This is evidenced by the sharp decrease in strain at this volume fraction of filler when compared to the strain of the unfilled polypropylene filament. Additionally, these same filaments suffered a sharp decrease in tenacity at the same volume fraction. These instant decreases are attributed to the agglomerations of filler in the filament. Generally, the modulus of the filaments increased with the increase in concentration of filler. The tensile tenacity, strain, and modulus were modeled with current composite models for particulate filled composites. The tenacity and strain models did not accurately predict the properties of the filaments, while the modulus models were more accurate, perhaps because the agglomerations of filler did not affect the modulus as much as it affected the tenacity and strain of the filaments. Production, characterization, and modeling of these filaments indicates that there are many areas for improvements, such as improved mixing of the filler and polypropylene, increased adhesion between matrix and filler, and decreased agglomerations of filler. Mechanically, these filaments can not match the properties of bone. However, they do have many structural similarities at the micro-mechanical level, so with some improvements in properties these filaments may be suitable models for modeling bone behavior.

Magnetorheological response of highly filled magnetoactive elastomers from perspective of mechanical energy density: Fractal aggregates above the nanometer scale?

PubMed

Sorokin, Vladislav V; Belyaeva, Inna A; Shamonin, Mikhail; Kramarenko, Elena Yu

2017-06-01

The dynamic shear modulus of magnetoactive elastomers containing 70 and 80 mass % of carbonyl iron microparticles is measured as a function of strain amplitude via dynamic torsion oscillations in various magnetic fields. The results are presented in terms of the mechanical energy density and considered in the framework of the conventional Kraus model. The form exponent of the Kraus model is further related to a physical model of Huber et al. [Huber et al., J. Phys.: Condens. Matter 8, 409 (1996)10.1088/0953-8984/8/29/003] that uses a realistic representation for the cluster network possessing fractal structure. Two mechanical loading regimes are identified. At small strain amplitudes the exponent β of the Kraus model changes in an externally applied magnetic field due to rearrangement of ferromagnetic-filler particles, while at large strain amplitudes, the exponent β seems to be independent of the magnetic field. The critical mechanical energy characterizing the transition between these two regimes grows with the increasing magnetic field. Similarities between agglomeration and deagglomeration of magnetic filler under simultaneously applied magnetic field and mechanical shear and the concept of jamming transition are discussed. It is proposed that the magnetic field should be considered as an additional parameter to the jamming phase diagram of rubbers filled with magnetic particles.

Passive Cooling Enabled by Polymer Composite Coating: Dependence on Filler, Filler Size and Coating Thickness

NASA Astrophysics Data System (ADS)

Shao, Yue; Shi, Frank G.

2017-07-01

The effective passive radiation cooling that is enabled by silicone-based composites is investigated for its dependence on coating thickness and filler size in the range of nanometers to micrometers. It is established, contrary to prior reports, that the effective passive radiation cooling does not exhibit a filler size dependence, i.e., there is no optimal size at which a maximum cooling would be reached. However, the apparent cooling effect is filler type dependent and among the fillers investigated, Al2O3 exhibits the best apparent cooling effect. In addition, the apparent cooling effect is dependent on coating thickness: the thickness dependence is non-monotonic, and the maximum cooling occurs at an optimal thickness of 70 μm, regardless of filler type. Potential significant implications of the findings are also discussed.

Ultrasound detection and identification of cosmetic fillers in the skin.

PubMed

Wortsman, X; Wortsman, J; Orlandi, C; Cardenas, G; Sazunic, I; Jemec, G B E

2012-03-01

While the incidence of cosmetic filler injections is rising world-wide, neither exact details of the procedure nor the agent used are always reported or remembered by the patients. Thus, although complications are reportedly rare, availability of a precise diagnostic tool to detect cutaneous filler deposits could help clarify the association between the procedure and the underlying pathology. The aim of this study was to evaluate cutaneous sonography in the detection and identification of cosmetic fillers deposits and, describe dermatological abnormalities found associated with the presence of those agents. We used ultrasound in a porcine skin model to determine the sonographic characteristics of commonly available filler agents, and subsequently applied the analysis to detect and identify cosmetic fillers among patients referred for skin disorders. Fillers are recognizable on ultrasound and generate different patterns of echogenicity and posterior acoustic artefacts. Cosmetic fillers were identified in 118 dermatological patients; most commonly hyaluronic acid among degradable agents and silicone oil among non-degradable. Fillers deposits were loosely scattered throughout the subcutaneous tissue, with occasional infiltration of local muscles and loco-regional lymph nodes. Accompanying dermatopathies were represented by highly localized inflammatory processes unresponsive to conventional treatment, morphea-like reactions, necrosis of fatty tissue and epidermal cysts; in the case of non-degradable agents, the associated dermatopathies were transient, resolving upon disappearance of the filler. Cosmetic filler agents may be detected and identified during routine ultrasound of dermatological lesions; the latter appear to be pathologically related to the cosmetic procedure. © 2011 The Authors. Journal of the European Academy of Dermatology and Venereology © 2011 European Academy of Dermatology and Venereology.

High reactive sulphide chemically supported on silica surface to prepare functional nanoparticle

NASA Astrophysics Data System (ADS)

Chen, Lijuan; Guo, Xiaohui; Jia, Zhixin; Tang, Yuhan; Wu, Lianghui; Luo, Yuanfang; Jia, Demin

2018-06-01

A solid-phase preparation method was applied to obtain a novel, green and effective functional nanoparticle, silica-supported sulfur monochloride (silica-s-S2Cl2), by the chemical reaction between chlorine atom and silicon hydroxyl on the silica surface. Through this chemical reaction, silica surface supported with high content of sulfur, and the functional nanoparticles can not only vulcanize the rubber instead of sulfur or other vulcanizing agent with high performance, but also improve the filler-rubber interaction as a modifier due to the improved modification effect. 29Si NMR, Raman spectroscopy, Element analysis and TGA confirm that the sulfur monochloride is chemically bonded on the silica surface. Cure properties measurement, morphology of filler dispersion, mechanical properties measurement, immobilized polymer layer and oxidation induction time increment together show that the novel vulcanizing agent silica-s-S2Cl2 instead of sulfur in rubber vulcanization gives rise to significant improvement in the crosslinking density and the interfacial adhesion between silica particles and the rubber matrix, which is on account of the promoted vulcanizing on the functional silica nanoparticles surface with the supported sulfur.

Incorporating Graphene Oxide into Alginate Polymer with a Cationic Intermediate To Strengthen Membrane Dehydration Performance.

PubMed

Guan, Kecheng; Liang, Feng; Zhu, Haipeng; Zhao, Jing; Jin, Wanqin

2018-04-25

Two-dimensional graphene oxide (GO) in hybrid membranes provides fast water transfer across its surface due to the abundant oxygenated functional groups to afford water sorption and the hydrophobic basal plane to create fast transporting pathways. To establish more compatible and efficient interactions for GO and sodium alginate (SA) polymer chains, cations sourced from lignin are employed to decorate GO (labeled as cation-functionalized GO (CG)) nanosheets via cation-π and π-π interactions, providing more interactive sites to confer synergetic benefits with polymer matrix. Cations from CG are also functional to partially interlock SA chains and intensify water diffusion. And with the aid of two-dimensional pathways of CG, fast selective water permeation can be realized through hybrid membranes with CG fillers. In dehydrating aqueous ethanol solution, the hybrid membrane exhibits considerable performance compared with bare SA polymer membrane (long-term stable permeation flux larger than 2500 g m -2 h -1 and water content larger than 99.7 wt %, with feed water content of 10 wt % under 70 °C). The effects of CG content in SA membrane were investigated, and the transport mechanism was correspondingly studied through varying operation conditions and membrane materials. In addition, such a membrane possesses long-term stability and almost unchanged high dehydration capability.

Improved fiber retention by the use of fillers in graphite fiber/resin matrix composites

NASA Technical Reports Server (NTRS)

Gluyas, R. E.; Bowles, K. J.

1980-01-01

A variety of matrix fillers were tested for their ability to prevent loss of fiber from graphite fiber/PMR polyimide and graphite fiber/epoxy composites in a fire. The fillers tested included powders of boron, boron carbide lime glass, lead glass, and aluminum. Boron was the most effective and prevented any loss of graphite fiber during burning. Mechanical properties of composites containing boron filler were measured and compared to those of composites containing no filler.

Halloysite nanotubes loaded with peppermint essential oil as filler for functional biopolymer film.

PubMed

Biddeci, G; Cavallaro, G; Di Blasi, F; Lazzara, G; Massaro, M; Milioto, S; Parisi, F; Riela, S; Spinelli, G

2016-11-05

The purpose of this paper is to show how a functional bionanocomposite film with both antioxidant and antimicrobial activities was successfully prepared by the filling of a pectin matrix with modified Halloysite nanotubes (HNT) containing the essential peppermint oil (PO). Firstly, HNT surfaces were functionalized with cucurbit[6]uril (CB[6]) molecules with the aim to enhance the affinity of the nanofiller towards PO, which was estimated by means of HPLC experiments. The HNT/CB[6] hybrid was characterized by several methods (thermogravimetry, FT-IR spectroscopy and scanning electron microscopy) highlighting the influence of the supramolecular interactions on the composition, thermal behavior and morphology of the filler. Then, a pectin+HNT/CB[6] biofilm was prepared by the use of the casting method under specific experimental conditions in order to favor the entrapment of the volatile PO into the nanocomposite structure. Water contact angle measurements, thermogravimetry and tensile tests evidenced the effects of the modified filler on the thermo-mechanical and wettability properties of pectin, which were correlated to the microscopic structure of the biocomposite film. In addition, PO release in food simulant solvent was investigated at different temperatures (4 and 25°C), whereas the antioxidant activity of the nanocomposite film was estimated using the DPPH method. Finally, we studied the in vitro antibacterial activity of the biofilm against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive), which were isolated by beef and cow milk, respectively. These experiments were carried out at specific temperatures (4, 37 and 65°C) that can be useful for a multi-step food conservation. This paper puts forwards an easy strategy to prepare a functional sustainable edible film with thermo-sensitive antioxidant/antimicrobial activity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Developing the multiple stress-strain creep recovery (MS-SCR) test

NASA Astrophysics Data System (ADS)

Elnasri, Mahmoud; Airey, Gordon; Thom, Nick

2018-04-01

While most published work from Europe has been concerned with evaluating binders' resistance to rutting based on their stiffness (deformation resistance), work originating in the US has mainly been concerned with ranking binders based on their recoverability in a multiple stress form. This paper details the design of a new modified multiple stress-strain creep recovery (MS-SCR) test. The test is designed to evaluate binders' rutting resistance based on two rutting resistance mechanisms: stiffness and recoverability. A preliminary investigation is presented in this paper followed by details of the design of the new modified test. A 40/60 penetration grade bitumen and bitumen-filler mastics prepared with three filler concentrations (35%, 50%, and 65% filler content by mass of mastic) were tested. In addition, two polymer modified bitumens (PMBs) using the same base bitumen type were examined for validation. Two parameters are introduced to characterise the short and long recovery in the new test. In terms of stiffness, the test allows the behaviour of binders at different stress levels and loading cycles to be studied and produces a new parameter that can quantify the degree of modification. Finally, a relationship between nonlinearity and normal force in the test was investigated.

Mixed matrix membrane incorporated with large pore size halloysite nanotubes (HNT) as filler for gas separation: experimental.

PubMed

Hashemifard, S A; Ismail, A F; Matsuura, T

2011-07-15

This study investigated the gas separation and transport properties of asymmetric mixed matrix membranes (MMM) fabricated from polyetherimide (PEI); Ultem 1000 incorporated with raw and modified halloysite nanotubes (HNT) as filler. The modified HNTs; S-HNTs were prepared by treating HNTs with N-β-(aminoethyl)-γ-aminopropyltrimethoxy silane (AEAPTMS). FESEM, XRD, FTIR, TGA, DSC and pure gas permeation testing were used to characterise the S-HNTs and the fabricated MMMs. In the first part of the experiments, the effect of dope preparation factors such as: ultrasonic sonication period, filler wetting period and priming period were investigated. In the second part, the influence of silane concentration on the fabricated MMMs was studied. Results showed that, increasing the silane concentration, led to higher tendency in HNT agglomeration which resulted in poor separation properties but permeability enhancement. In the last part, the effect of S-HNTs loading was experienced. Our observations showed that the dispersion of nanoparticles decreased with an increase in the S-HNTs loading. Accordingly, 0.5% loading of silylated-HNT yielded the optimum MMMs in terms of permeability (27% increase) and selectivity (8% increase). Copyright © 2011 Elsevier Inc. All rights reserved.

Hyaluronic acid fillers with cohesive polydensified matrix for soft-tissue augmentation and rejuvenation: a literature review

PubMed Central

Prasetyo, Adri D; Prager, Welf; Rubin, Mark G; Moretti, Ernesto A; Nikolis, Andreas

2016-01-01

Background Cohesive monophasic polydensified fillers show unique viscoelastic properties and variable density of hyaluronic acid, allowing for a homogeneous tissue integration and distribution of the material. Objective The aim of this paper was to review the clinical data regarding the performance, tolerability, and safety of the Belotero® fillers for soft-tissue augmentation and rejuvenation. Methods A literature search was performed up until May 31, 2015 to identify all relevant articles on Belotero® fillers (Basic/Balance, Hydro, Soft, Intense, Volume) and equivalent products (Esthélis®, Mesolis®, Fortélis®, Modélis®). Results This comprehensive review included 26 papers. Findings from three randomized controlled trials showed a greater reduction in nasolabial fold severity with Belotero® Basic/Balance than with collagen (at 8, 12, 16, and 24 weeks, n=118) and Restylane® (at 4 weeks, n=40), and higher patient satisfaction with Belotero® Intense than with Perlane® (at 2 weeks, n=20). With Belotero® Basic/Balance, an improvement of at least 1 point on the severity scale can be expected in ~80% of patients 1–6 months after injection, with an effect still visible at 8–12 months. Positive findings were also reported with Belotero® Volume (no reduction in hyaluronic acid volume at 12 months, as demonstrated by magnetic resonance imaging), Soft (improvement in the esthetic outcomes when used in a sequential approach), and Hydro (improvement in skin appearance in all patients). The most common adverse effects were mild-to-moderate erythema, edema, and hematoma, most of which were temporary. There were no reports of Tyndall effect, nodules, granulomas, or tissue necrosis. Conclusion Clinical evidence indicates sustainable esthetic effects, good safety profile, and long-term tolerability of the Belotero® fillers, particularly Belotero® Basic/Balance and Intense. PMID:27660479

46 CFR 57.02-5 - Filler metals.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Filler metals. 57.02-5 Section 57.02-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING WELDING AND BRAZING General Requirements § 57.02-5 Filler metals. (a) Except as provided for in paragraph (b) of this section, when filler...

Mechanical properties of heterophase polymer blends of cryogenically fractured soy flour composite filler and poly(styrene-butadiene)

USDA-ARS?s Scientific Manuscript database

Reinforcement effect of cryogenically fractured soy Flour composite filler in soft polymer was investigated in this study. Polymer composites were prepared by melt-mixing polymer and soy flour composite fillers in an internal mixer. Soy flour composite fillers were prepared by blending aqueous dis...

46 CFR 57.02-5 - Filler metals.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 2 2013-10-01 2013-10-01 false Filler metals. 57.02-5 Section 57.02-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING WELDING AND BRAZING General Requirements § 57.02-5 Filler metals. (a) Except as provided for in paragraph (b) of this section, when filler...

46 CFR 57.02-5 - Filler metals.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 2 2014-10-01 2014-10-01 false Filler metals. 57.02-5 Section 57.02-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING WELDING AND BRAZING General Requirements § 57.02-5 Filler metals. (a) Except as provided for in paragraph (b) of this section, when filler...

46 CFR 57.02-5 - Filler metals.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 2 2012-10-01 2012-10-01 false Filler metals. 57.02-5 Section 57.02-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING WELDING AND BRAZING General Requirements § 57.02-5 Filler metals. (a) Except as provided for in paragraph (b) of this section, when filler...

46 CFR 57.02-5 - Filler metals.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 2 2011-10-01 2011-10-01 false Filler metals. 57.02-5 Section 57.02-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING WELDING AND BRAZING General Requirements § 57.02-5 Filler metals. (a) Except as provided for in paragraph (b) of this section, when filler...

Comparative study on thermodynamic characteristics of AgCuZnSn brazing alloys

NASA Astrophysics Data System (ADS)

Wang, Xingxing; Li, Shuai; Peng, Jin

2018-01-01

AgCuZnSn brazing alloys were prepared based on the BAg50CuZn filler metal through electroplating diffusion process, and melting alloying method. The thermodynamics of phase transformations of those fillers were analyzed by non-isothermal differentiation and integration methods of thermal analysis kinetics. In this study, it was demonstrated that as the Sn content increased, the reaction fractional integral curves of AgCuZnSn fillers from solid to liquid became straighter at the endothermic peak. Under the same Sn contents, the reaction fractional integral curve of the Sn-plated filler metal was straighter, and the phase transformation activation energy was higher compared to the traditional silver filler metal. At the 7.2 wt% Sn content, the activation energies and pre-exponential factors of the two fillers reached the maximum, then the phase transformation rate equations of the Sn-plated silver filler and the traditional filler were determined as: k = 1.41 × 1032exp(-5.56 × 105/RT), k = 7.29 × 1020exp(-3.64 × 105/RT), respectively.

Thermal, Morphological and Rheological Properties of Rigid Polyurethane Foams as Thermal Insulating Materials

NASA Astrophysics Data System (ADS)

Kim, Ji Mun; Han, Mi Sun; Kim, Youn Hee; Kim, Woo Nyon

2008-07-01

The polyurethane foams (PUFs) were prepared by polyether polyols, polymeric 4,4'-diphenylmethane diisocyanate (PMDI), silicone surfactants, amine catalysts and cyclopentane as a blowing agent. Solid and liquid type fillers were used as a nucleating agent to decrease a cell size of the PUFs as well as improve the thermal insulating properties of the PUFs. The PUFs were prepared by adding solid and liquid type fillers in the range of 1 to 3 wt%. For the liquid type fillers, the cell size of the PUFs showed minimum and found to decrease compared the PUF without adding fillers. Also, thermal conductivity of the PUFs with adding fillers showed minimum. For the solid type fillers, cell size and thermal conductivity of the PUFs were observed to decrease with the filler content up to 3 wt%. From these results, it is suggested that the thermal insulating property of the PUFs can be improved by adding fillers as a nucleating agent. Also, storage and loss modulus of the PUFs will be presented to study gelling points of the PUFs.

Vibration anesthesia for the reduction of pain with facial dermal filler injections.

PubMed

Mally, Pooja; Czyz, Craig N; Chan, Norman J; Wulc, Allan E

2014-04-01

Vibration anesthesia is an effective pain-reduction technique for facial cosmetic injections. The analgesic effect of this method was tested in this study during facial dermal filler injections. The study aimed to evaluate the safety and efficacy of vibration anesthesia for these facial injections. This prospective study analyzed 41 patients who received dermal filler injections to the nasolabial folds, tear troughs, cheeks, and other facial sites. The injections were administered in a randomly assigned split-face design. One side of the patient's face received vibration together with dermal filler injections, whereas the other side received dermal filler injections alone. The patients completed a posttreatment questionnaire pertaining to injection pain, adverse effects, and preference for vibration with future dermal filler injections. The patients experienced both clinically and statistically significant pain reduction when a vibration stimulus was co-administered with the dermal filler injections. No adverse events were reported. The majority of the patients (95 %) reported a preference for vibration anesthesia with subsequent dermal filler injections. Vibration is a safe and effective method of achieving anesthesia during facial dermal filler injections. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Organic filler from golden apple snails shells to improve the silicone rubber insulator properties

NASA Astrophysics Data System (ADS)

Tepsila, Sujirat; Suksri, Amnart

2018-02-01

This paper investigates the effect of an addition of filler compound using golden apple snail shell as an organic filler to the silicone rubber insulator. The filler obtained from golden apple snail shell is found mostly contained calcium carbonate. The organic calcium carbonate (CaCO3) with particle size of 45, 75, 100 and 300 micron were prepared. Sample of silicone rubber that were filled with fillers were tested under ASTM D638-02a type standard for mechanical test. Also, electrical test such as I-V characteristics (ASTM D257-07) and dry arc test according to ASTM D495-14 have been performed. The results revealed that using larger particle size of organic filler obtained from the golden apple snail shell resulted to higher value of dielectric constant as well as higher dielectric strength. Also, the filler helps slow down the tracking activity at an insulator surface due to its crystals of calcium carbonate. However, when using excessive amount of filler, the sample will have a drawbacks in mechanical properties. By using agriculture waste as a filler compound, one can reduced the usage of commercial CaCO3 as an inorganic materials and to lower the investment cost to a final silicone rubber product.

Crosslinked hyaluronic acid dermal fillers: a comparison of rheological properties.

PubMed

Falcone, Samuel J; Berg, Richard A

2008-10-01

Temporary dermal fillers composed of crosslinked hyaluronic acid (XLHA) are space filling gels that are readily available in the United States and Europe. Several families of dermal fillers based on XLHA are now available and here we compare the physical and rheological properties of these fillers to the clinical effectiveness. The XLHA fillers are prepared with different crosslinkers, using HA isolated from different sources, have different particle sizes, and differ substantially in rheological properties. For these fillers, the magnitude of the complex viscosity, |eta*|, varies by a factor of 20, the magnitude of the complex rigidity modulus, |G*|, and the magnitude of the complex compliance, |J*| vary by a factor of 10, the percent elasticity varies from 58% to 89.9%, and the tan delta varies from 0.11 to 0.70. The available clinical data cannot be correlated with either the oscillatory dynamic or steady flow rotational rheological properties of the various fillers. However, the clinical data appear to correlate strongly with the total concentration of XLHA in the products and to a lesser extent with percent elasticity. Hence, our data suggest the following correlation: dermal filler persistence = [polymer] x [% elasticity] and the clinical persistence of a dermal filler composed of XLHA is dominated by the mass and elasticity of the material implanted. This work predicts that the development of future XLHA dermal filler formulations should focus on increasing the polymer concentration and elasticity to improve the clinical persistence.

Effect of mechanical properties of fillers on the grindability of composite resin adhesives.

PubMed

Iijima, Masahiro; Muguruma, Takeshi; Brantley, William A; Yuasa, Toshihiro; Uechi, Jun; Mizoguchi, Itaru

2010-10-01

The purpose of this study was to investigate the effect of filler properties on the grindability of composite resin adhesives. Six composite resin products were selected: Transbond XT (3M Unitek, Monrovia, Calif), Transbond Plus (3M Unitek), Enlight (Ormco, Glendora, Calif), Kurasper F (Kuraray Medical, Tokyo, Japan), Beauty Ortho Bond (Shofu, Kyoto, Japan), and Beauty Ortho Bond Salivatect (Shofu). Compositions and weight fractions of fillers were determined by x-ray fluorescence analysis and ash test, respectively. The polished surface of each resin specimen was examined with a scanning electron microscope. Vickers hardness of plate specimens (15 × 10 × 3 mm) was measured, and nano-indentation was performed on large filler particles (>10 μm). Grindability for a low-speed tungsten-carbide bur was estimated. Data were compared with anlaysis of variance (ANOVA) and the Tukey multiple range test. Relationships among grindability, filler content, filler nano-indentation hardness (nano-hardness), filler elastic modulus, and Vickers hardness of the composite resins were investigated with the Pearson correlation coefficient test. Morphology and filler size of these adhesives showed great variations. The products could be divided into 2 groups, based on composition, which affected grindability. Vickers hardness of the adhesives did not correlate (r = 0.140) with filler nano-hardness, which showed a significant negative correlation (r = -0.664) with grindability. Filler nano-hardness greatly influences the grindability of composite resin adhesives. Copyright © 2010 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Suspect filler similarity in eyewitness lineups: a literature review and a novel methodology.

PubMed

Fitzgerald, Ryan J; Oriet, Chris; Price, Heather L

2015-02-01

Eyewitness lineups typically contain a suspect (guilty or innocent) and fillers (known innocents). The degree to which fillers should resemble the suspect is a complex issue that has yet to be resolved. Previously, researchers have voiced concern that eyewitnesses would be unable to identify their target from a lineup containing highly similar fillers; however, our literature review suggests highly similar fillers have only rarely been shown to have this effect. To further examine the effect of highly similar fillers on lineup responses, we used morphing software to create fillers of moderately high and very high similarity to the suspect. When the culprit was in the lineup, a higher correct identification rate was observed in moderately high similarity lineups than in very high similarity lineups. When the culprit was absent, similarity did not yield a significant effect on innocent suspect misidentification rates. However, the correct rejection rate in the moderately high similarity lineup was 20% higher than in the very high similarity lineup. When choosing rates were controlled by calculating identification probabilities for only those who made a selection from the lineup, culprit identification rates as well as innocent suspect misidentification rates were significantly higher in the moderately high similarity lineup than in the very high similarity lineup. Thus, very high similarity fillers yielded costs and benefits. Although our research suggests that selecting the most similar fillers available may adversely affect correct identification rates, we recommend additional research using fillers obtained from police databases to corroborate our findings.

Working Memory in the Processing of Long-Distance Dependencies: Interference and Filler Maintenance

ERIC Educational Resources Information Center

Ness, Tal; Meltzer-Asscher, Aya

2017-01-01

During the temporal delay between the filler and gap sites in long-distance dependencies, the "active filler" strategy can be implemented in two ways: the filler phrase can be actively maintained in working memory ("maintenance account"), or it can be retrieved only when the parser posits a gap ("retrieval account").…

Polyvinyl alcohol battery separator containing inert filler. [alkaline batteries

NASA Technical Reports Server (NTRS)

Sheibley, D. W.; Hsu, L. C.; Manzo, M. A. (Inventor)

1981-01-01

A cross-linked polyvinyl alcohol battery separator is disclosed. A particulate filler, inert to alkaline electrolyte of an alkaline battery, is incorporated in the separator in an amount of 1-20% by weight, based on the weight of the polyvinyl alcohol, and is dispersed throughout the product. Incorporation of the filler enhances performance and increases cycle life of alkaline batteries when compared with batteries containing a similar separator not containing filler. Suitable fillers include titanates, silicates, zirconates, aluminates, wood floor, lignin, and titania. Particle size is not greater than about 50 microns.

Biodegradation of natural reinforcing fillers for polymer composites

NASA Astrophysics Data System (ADS)

Mastalygina, E. E.; Pantyukhov, P. V.; Popov, A. A.

2018-05-01

Twelve different natural raw materials were selected as possible fillers for eco-friendly biocomposites. The target was to find the most biodegradable ones. Two mycological tests were held: in the aqueous and agar media. It was found that two tests showed different results. In aqueous media, the fillers with a high content of water-soluble and easy-hydrolysed compounds demostrated the most intensive biofouling. In agar media, the entire filler was exposed to biodigestion by fungi. Therefore, multi-compound fillers with a set of different macro- and microelements were more biodegradable than others.

Recommendations for Filler Material Composition and Delivery Method for Bench-Scale Testing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hardin, Ernest; Brady, Patrick Vane

This report supplements Joint Workplan on Filler Investigations for DPCs (SNL 2017) providing new and some corrected information for use in planning Phase 1 laboratory testing of slurry cements as possible DPC fillers. The scope description is to "Describe a complete laboratory testing program for filler composition, delivery, emplacement in surrogate canisters, and post-test examination. To the extent possible specify filler material and equipment sources." This report includes results from an independent expert review (Dr. Arun Wagh, retired from Argonne National Laboratory and contracted by Sandia) that helped to narrow the range of cement types for consideration, and to providemore » further guidance on mix variations to optimize injectability, durability, and other aspects of filler performance.« less

Hot cracking susceptibility of fillers 52 and 82 in alloy 690 welding

NASA Astrophysics Data System (ADS)

Wu, Weite; Tsai, C. H.

1999-02-01

The hot cracking susceptibility of fillers 52 and 82 in a alloy 690 weldment is analyzed by the Varestraint test. Weld characteristics, microstructure, hardness distribution, and thermal analysis of the two filler metals are also examined. The weld metal of both fillers develops an extremely dense oxide layer. A stainless steel brush cannot remove the oxide layer, and a grinder may be needed between weld passes to assure a sound weld. Differential temperature analysis (DTA) shows that filler 82 has a lower melting point and a wider melting/solidification temperature differential (Δ T). These characteristics correlate with greater hot cracking susceptibility of filler 82 than 52 in Varestraint tests. The hot cracks are intergranular and are caused by elements segregating in grain boundies.

Biodegradation behavior of styrene butadiene rubber (SBR) reinforced with modified coconut shell powder

NASA Astrophysics Data System (ADS)

Sreejith, M. P.; Balan, Aparna K.; Shaniba, V.; Jinitha, T. V.; Subair, N.; Purushothaman, E.

2017-06-01

Biodegradation behavior of styrene butadiene rubber composites reinforced with natural filler, coconut shell powder (CSP), with different filler loadings were carried out under soil burial conditions for three to six months. The extent of biodegradation of the composites was evaluated through weight loss, tensile strength and hardness measurements. It was observed that the permanence of the composites was remarkably dependent on filler modification, size of the filler particle and filler content. Composites containing silane modified filler were found to be more resistant to attack by the microbes present in the soil. Mechanical properties such as tensile strength, Young's modulus and hardness were decreased after soil burial testing due to the microbial attack onto the samples.

The Efficacy, Longevity, and Safety of Combined Radiofrequency Treatment and Hyaluronic Acid Filler for Skin Rejuvenation

PubMed Central

Kim, Hyuk; Park, Kui Young; Choi, Sun Young; Koh, Hyun-Ju; Park, Sun-Young; Park, Won-Seok; Bae, Il-Hong

2014-01-01

Background Recent advances in hyaluronic acid (HA) fillers and radiofrequency (RF) devices have been made in the context of skin rejuvenation and cosmetic surgery. Moreover, combination regimens with both techniques are currently being developed. Objective The present study was designed to examine the clinical and histologic effects of a new needle that incorporates an RF device for HA injections. Methods A new intradermal needle RF device (INNOfill; Pacific Pharma, Korea) was assessed in the present study. In the animal arm, procollagen production was measured by using enzyme-linked immunosorbent assay, the filler volume was quantified by incorporating a dye with filler, and the filler distribution was assessed through the changes in tissue structure. In the human arm, the efficacy of the combination regimen was assessed by using the wrinkle severity rating scale (WSRS). Results In the animal study, RF treatment increased procollagen production in a time-dependent fashion. The total volume was significantly increased with the RF treatment when compared with the filler injections alone, and lasted for up to 7 weeks after treatment. Additionally, the filler distribution was reduced in animals treated with RF when compared with the untreated group. In the human study, the nasolabial folds of subjects treated with RF before filler injections exhibited a significantly greater change in the WSRS score from baseline when compared with the nasolabial folds treated with filler injections alone. Conclusion A new device incorporating RF treatment before HA filler injection may represent a biocompatible and long-lasting advance in skin rejuvenation. PMID:25143672

Evaluation and improvement of micro-surfacing mix design method and modelling of asphalt emulsion mastic in terms of filler-emulsion interaction

NASA Astrophysics Data System (ADS)

Robati, Masoud

This Doctorate program focuses on the evaluation and improving the rutting resistance of micro-surfacing mixtures. There are many research problems related to the rutting resistance of micro-surfacing mixtures that still require further research to be solved. The main objective of this Ph.D. program is to experimentally and analytically study and improve rutting resistance of micro-surfacing mixtures. During this Ph.D. program major aspects related to the rutting resistance of micro-surfacing mixtures are investigated and presented as follow: 1) evaluation of a modification of current micro-surfacing mix design procedures: On the basis of this effort, a new mix design procedure is proposed for type III micro-surfacing mixtures as rut-fill materials on the road surface. Unlike the current mix design guidelines and specification, the new mix design is capable of selecting the optimum mix proportions for micro-surfacing mixtures; 2) evaluation of test methods and selection of aggregate grading for type III application of micro-surfacing: Within the term of this study, a new specification for selection of aggregate grading for type III application of micro-surfacing is proposed; 3) evaluation of repeatability and reproducibility of micro-surfacing mixture design tests: In this study, limits for repeatability and reproducibility of micro-surfacing mix design tests are presented; 4) a new conceptual model for filler stiffening effect on asphalt mastic of micro-surfacing: A new model is proposed, which is able to establish limits for minimum and maximum filler concentrations in the micro-surfacing mixture base on only the filler important physical and chemical properties; 5) incorporation of reclaimed asphalt pavement and post-fabrication asphalt shingles in micro-surfacing mixture: The effectiveness of newly developed mix design procedure for micro-surfacing mixtures is further validated using recycled materials. The results present the limits for the use of RAP and RAS amount in micro-surfacing mixtures; 6) new colored micro-surfacing formulations with improved durability and performance: The significant improvement of around 45% in rutting resistance of colored and conventional micro-surfacing mixtures is achieved through employing low penetration grade bitumen polymer modified asphalt emulsion stabilized using nanoparticles.

Selecting fillers on emotional appearance improves lineup identification accuracy.

PubMed

Flowe, Heather D; Klatt, Thimna; Colloff, Melissa F

2014-12-01

Mock witnesses sometimes report using criminal stereotypes to identify a face from a lineup, a tendency known as criminal face bias. Faces are perceived as criminal-looking if they appear angry. We tested whether matching the emotional appearance of the fillers to an angry suspect can reduce criminal face bias. In Study 1, mock witnesses (n = 226) viewed lineups in which the suspect had an angry, happy, or neutral expression, and we varied whether the fillers matched the expression. An additional group of participants (n = 59) rated the faces on criminal and emotional appearance. As predicted, mock witnesses tended to identify suspects who appeared angrier and more criminal-looking than the fillers. This tendency was reduced when the lineup fillers matched the emotional appearance of the suspect. Study 2 extended the results, testing whether the emotional appearance of the suspect and fillers affects recognition memory. Participants (n = 1,983) studied faces and took a lineup test in which the emotional appearance of the target and fillers was varied between subjects. Discrimination accuracy was enhanced when the fillers matched an angry target's emotional appearance. We conclude that lineup member emotional appearance plays a critical role in the psychology of lineup identification. The fillers should match an angry suspect's emotional appearance to improve lineup identification accuracy. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Effect on mechanical properties of glass reinforced epoxy (GRE) pipe filled with different geopolymer filler molarity for piping application

NASA Astrophysics Data System (ADS)

Hashim, M. F. Abu; Abdullah, M. M. A.; Ghazali, C. M. R.; Hussin, K.; Binhussain, M.

2017-04-01

This study investigated the use of a novel white clay geopolymer as a filler to produce high strength glass reinforced epoxy pipe. It was found that using white clay geopolymer as filler gives better compressive strength to the glass reinforced epoxy pipe. The disadvantages of current glass reinforced epoxy pipes such low compressive strength which can be replaced by the composite pipes. Geopolymerization is an innovative technology that can transform several aluminosilicate materials into useful products called geopolymers or inorganic polymers. A series of glass reinforced epoxy pipe and glass reinforced epoxy pipe filled with 10 - 40 weight percentages white clay geopolymer filler with 4 Molarity and 8 Molarity were prepared. Morphology of white clay geopolymer filler surface was indicates using scanning electron microscopy. The additions of white clay geopolymer filler for both 4 Molarity and 8 Molarity show higher compressive strength than glass reinforced epoxy pipe without any geopolymer filler. The compressive test of these epoxy geopolymer pipe samples was determined using Instron Universal Testing under compression mode. Nonetheless, the compressive strength of glass reinforced epoxy pipe with white clay geopolymer filler continues to drop when added to 40 wt% of the geopolymer filler loading for both 4 Molarity and 8 Molarity. These outcomes showed that the mixing of geopolymer materials in epoxy system can be attained in this research.

Bioinspired Catecholic Primers for Rigid and Ductile Dental Resin Composites.

PubMed

Shin, Eeseul; Ju, Sung Won; An, Larry; Ahn, Eungjin; Ahn, Jin-Soo; Kim, Byeong-Su; Ahn, B Kollbe

2018-01-17

In the construction of dental restorative polymer composite materials, surface priming on mineral fillers is essential to improve the mechanical performance of the composites. Here we present bioinspired catechol-functionalized primers for a tougher dental resin composite containing glass fillers. The catecholic primers with different polymerizable end groups were designed and then coated on glass surfaces using a simple drop-casting or dip-coating process. The surface binding ability and possible cross-linking (coupling or chemical bridging between the glass substrate and the dental resin) of the catecholic bifunctional primers were evaluated using atomic force microscopy, contact angle measurements, and the knife shear bonding test and compared to a state-of-the-art silane-based coupling agent. Various mechanical tests including shrinkage and compression tests of the dental resin composites were also conducted. Compression tests of the composites containing the catecholic primed fillers exhibited enhanced mechanical properties, owing to the bidentate hydrogen bonding of catechol moieties to the oxide mineral surface. Furthermore, the superior biocompatibility of the primed surface was confirmed via cell attachment assay, thus providing applicability of catecholic primers for practical dental and biomedical applications.

Melting Point Depression and Fast Diffusion in Nanostructured Brazing Fillers Confined Between Barrier Nanolayers

NASA Astrophysics Data System (ADS)

Kaptay, G.; Janczak-Rusch, J.; Jeurgens, L. P. H.

2016-08-01

Successful brazing using Cu-based nanostructured brazing fillers at temperatures much below the bulk melting temperature of Cu was recently demonstrated (Lehmert et al. in, Mater Trans 56:1015-1018, 2015). The Cu-based nano-fillers are composed of alternating nanolayers of Cu and a permeable, non-wetted AlN barrier. In this study, a thermodynamic model is derived to estimate the melting point depression (MPD) in such Cu/AlN nano-multilayers (NMLs) as function of the Cu nanolayer thickness. Depending on the melting route, the model predicts a MPD range of 238-609 K for Cu10nm/AlN10nm NMLs, which suggests a heterogeneous pre-melting temperature range of 750-1147 K (476-874 °C), which is consistent with experimental observations. As suggested by basic kinetic considerations, the observed Cu outflow to the NML surface at the temperatures of 723-1023 K (450-750 °C) can also be partially rationalized by fast solid-state diffusion of Cu along internal interfaces, especially for the higher temperatures.

Effects of Ion-Releasing Tooth-Coating Material on Demineralization of Bovine Tooth Enamel

PubMed Central

Kawasaki, Koji; Kambara, Masaki

2014-01-01

We compared the effect of a novel ion-releasing tooth-coating material that contained S-PRG (surface-reaction type prereacted glass-ionomer) filler to that of non-S-PRG filler and nail varnish on the demineralization of bovine enamel subsurface lesions. The demineralization process of bovine enamel was examined using quantitative light-induced fluorescence (QLF) and electron probe microanalyzer (EPMA) measurement. Ion concentrations in demineralizing solution were measured using inductively coupled plasma atomic (ICP) emission spectrometry and an ion electrode. The nail varnish group and the non-S-PRG filler group showed linear demineralization. Although the nail varnish group and the non-S-PRG filler group showed linear demineralization, the S-PRG filler group did not. Further, plane-scanning by EPMA analysis in the S-PRG filler group showed no changes in Ca ion distribution, and F ions showed peak levels on the surface of enamel specimens. Most ions in the demineralizing solution were present at higher concentrations in the S-PRG filler group than in the other two groups. In conclusion, only the S-PRG filler-containing tooth-coating material released ions and inhibited demineralization around the coating. PMID:24578706

Effect of filler type and polishing on the discoloration of composite resin artificial teeth.

PubMed

Imamura, Soichiro; Takahashi, Hidekazu; Hayakawa, Iwao; Loyaga-Rendon, Paola G; Minakuchi, Shunsuke

2008-11-01

In this study, the effects of filler type and polishing on the discoloration of composite resin artificial teeth were examined. Four types of experimental resins were prepared: one was a matrix resin, while the others were composite resins containing three different types of fillers (nano-sized silica filler with or without silanization, and prepolymerized filler). Specimens were immersed in distilled water, coffee, red wine, or curry. Color change after immersion was measured using a colorimeter. Color difference values (delta E) and changes in translucency parameter (delta TP) were statistically analyzed using three-way ANOVA and Tukey's comparison. On the influence of the polishing factor, statistically significant differences were neither observed in delta E nor delta TP between polished and non-polished tooth surfaces. On the contrary, the influences of filler type and discoloration medium, and their interaction thereof, were significant. With unsilanized filler, the delta E value of composite resin artificial teeth was significantly increased.

Influence of particle size on water absorption capacity and mechanical properties of polyethylene-wood flour composites

NASA Astrophysics Data System (ADS)

Zykova, A. K.; Pantyukhov, P. V.; Kolesnikova, N. N.; Popov, A. A.; Olkhov, A. A.

2015-10-01

Biocomposites based on low density polyethylene (LDPE) and birch wood flour (WF) were investigated. The mechanical properties and water absorption capacity were examined depending on the particle size of a filler in biocomposites. The aim of the paper is the investigation of composite properties depending on the filler particle size. The filler particle sizes were 0-80 µm, 80-140 µm, 140-200 µm, and 0-200 µm. The tensile strength of composite samples varied within the range 5.7-8.2 MPa. Elongation at break of composites varied within the range 5.1-7.5%. Highest mechanical properties were found in composites with the lowest filler fraction. Highest water absorption was observed in composition with a complex fraction of the filler. The influence of the filler particle size on composite properties was shown. It was found that an increase of the filler particle size decreases mechanical parameters and increases water absorption.

Advanced inorganic separators for alkaline batteries

NASA Technical Reports Server (NTRS)

Sheibley, D. W. (Inventor)

1982-01-01

A flexible, porous battery separator comprising a coating applied to a porous, flexible substrate is described. The coating comprises: (1) a thermoplastic rubber-based resin which is insoluble and unreactive in the alkaline electrolyte; (2) a polar organic plasticizer which is reactive with the alkaline electrolyte to produce a reaction product which contains a hydroxyl group and/or a carboxylic acid group; and (3) a mixture of polar particulate filler materials which are unreactive with the electrolyte, the mixture comprising at least one first filler material having a surface area of greater than 25 meters sq/gram, at least one second filler material having a surface area of 10 to 25 sq meters/gram, wherein the volume of the mixture of filler materials is less than 45% of the total volume of the fillers and the binder, the filler surface area per gram of binder is about 20 to 60 sq meters/gram, and the amount of plasticizer is sufficient to coat each filler particle. A method of forming the battery separator is also described.

Advanced inorganic separators for alkaline batteries and method of making the same

NASA Technical Reports Server (NTRS)

Sheibley, D. W. (Inventor)

1983-01-01

A flexible, porous battery separator includes a coating applied to a porous, flexible substrate. The coating comprises: (1) a thermoplastic rubber-based resin which is insoluble and unreactive in the alkaline electrolyte, (2) a polar organic plasticizer which is reactive with the alkaline electrolyte to produce a reaction product which contains a hydroxyl group and/or a carboxylic acid group, and (3) a mixture of polar particulate filler materials which are unreactive with the electrode. The mixture comprises at least one first filler material having a surface area of greater than 25 sq meters/gram, at last one second filler material having a surface area of 10 to 25 sq meters/gram. The volume of the mixture of filler materials is less than 45% of the total volume of the fillers and the binder. The filler surface area per gram of binder is about 20 to 60 sq meters/gram, and the amount of plasticizer is sufficient to coat each filler particle.

Quantitative characterization of brazing performance for Sn-plated silver alloy fillers

NASA Astrophysics Data System (ADS)

Wang, Xingxing; Peng, Jin; Cui, Datian

2017-12-01

Two types of AgCuZnSn fillers were prepared based on BAg50CuZn and BAg34CuZnSn alloy through a combinative process of electroplating and thermal diffusion. The models of wetting entropy and joint strength entropy of AgCuZnSn filler metals were established. The wetting entropy of the Sn-plated silver brazing alloys are lower than the traditional fillers, and its joint strength entropy value is slightly higher than the latter. The wetting entropy value of the Sn-plated brazing alloys and traditional filler metal are similar to the change trend of the wetting area. The trend of the joint strength entropy value with those fillers are consisted with the tensile strength of the stainless steel joints with the increase of Sn content.

Hot cracking susceptibility of fillers 52 and 82 in alloy 690 welding

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, W.; Tsai, C.H.

1999-02-01

The hot cracking susceptibility of fillers 52 and 82 in a alloy 690 weldment is analyzed by the Varestraint test. Weld characteristics, microstructure, hardness distribution, and thermal analysis of the two filler metals are also examined. The weld metal of both fillers develops an extremely dense oxide layer. A stainless steel brush cannot remove the oxide layer, and a grinder may be needed between weld passes to assure a sound weld. Differential temperature analysis (DTA) shows that filler 82 has a lower melting point and a wider melting/solidification temperature differential ({Delta} T). These characteristics correlate with greater hot cracking susceptibilitymore » of filler 82 than 52 in Varestraint tests. The hot cracks are intergranular and are caused by elements segregating in grain boundaries.« less

Filler metal alloy for welding cast nickel aluminide alloys

DOEpatents

Santella, Michael L.; Sikka, Vinod K.

1998-01-01

A filler metal alloy used as a filler for welding east nickel aluminide alloys contains from about 15 to about 17 wt. % chromium, from about 4 to about 5 wt. % aluminum, equal to or less than about 1.5 wt. % molybdenum, from about 1 to about 4.5 wt. % zirconium, equal to or less than about 0.01 wt. % yttrium, equal to or less than about 0.01 wt. % boron and the balance nickel. The filler metal alloy is made by melting and casting techniques such as are melting the components of the filler metal alloy and east in copper chill molds.

Novel antimicrobial and biofilm-controlling cellulosic polymers

NASA Astrophysics Data System (ADS)

Padmanabhuni, Revathi V.

Cotton and cellulose acetate (CA) are cellulosic polymers with versatile applications. Like any other polymeric materials, cellulosic materials are also susceptible to microbial contamination and cause serious nosocomial infections. Hence, there is a definite need to develop antimicrobial cellulosic materials to prevent microbial colonization. Henceforth, we prepared a suitable polycation to treat cotton fabrics and CA films by LbL self-assembly process to achieve potent antimicrobial functions. The treated fabrics demonstrated total kill against E. coli and S. aureus in 2 h contact time whereas treated CA films, even after 6 h, could inactivate only 98 % of bacteria. Since CA films are more hydrophobic, have less surface charge, and surface area than cotton fabrics, LbL procedure was not much effective for CA films to achieve potent antimicrobial functions. Yet, CA is another very important cellulosic polymer with various applications in which antimicrobial activity is often desired. So, to improve the antimicrobial activity of CA films, we designed a novel strategy to coat the surface of CaCO3 fillers with quaternary ammonium salts (QAS)based fatty acids to make the filler surface organophilic and accomplish antibacterial activity concurrently, rendering the resulting polymer-filler composites antimicrobial. Thus, a series of QAS-based fatty acids (C8-C16) were synthesized, coated onto CaCO 3, and used as antimicrobial additives (5 %) in CA films. Although C8-quat-CaCO 3 could only provide 94 % of reduction of bacteria, both C12- and C16- quats and their corresponding quat-coated CaCO3 provided a total kill of S. aureus and E. coli in 2 h. These findings suggested that it is feasible to use QAS-based fatty acids to coat CaCO3 and use them as antimicrobial additives of CA films to achieve potent antimicrobial effects. Building on these results, to further evaluate the applicability of the antimicrobial filler strategy, we synthesized an N-halamine based fatty acid, coated onto CaCO3 and used as antimicrobial additives in CA films; the resulting samples provided excellent antimicrobial and biofilm-controlling effects, confirming that the antimicrobial filler approach could be an effective strategy for the antimicrobial treatments of CA and potentially other related hydrophobic polymeric materials.

Wetting and spreading behavior of molten brazing filler metallic alloys on metallic substrate

NASA Astrophysics Data System (ADS)

Kogi, Satoshi; Kajiura, Tetsurou; Hanada, Yukiakira; Miyazawa, Yasuyuki

2014-08-01

Wetting and spreading of molten brazing filler material are important factors that influence the brazing ability of a joint to be brazed. Several investigations into the wetting ability of a brazing filler alloy and its surface tension in molten state, in addition to effects of brazing time and temperature on the contact angle, have been carried out. In general, dissimilar-metals brazing technology and high-performance brazed joint are necessities for the manufacturing field in the near future. Therefore, to address this requirement, more such studies on wetting and spreading of filler material are required for a deeper understanding. Generally, surface roughness and surface conditions affect spreading of molten brazing filler material during brazing. Wetting by and interfacial reactions of the molten brazing filler material with the metallic substrate, especially, affect strongly the spreading of the filler material. In this study, the effects of surface roughness and surface conditions on the spreading of molten brazing filler metallic alloys were investigated. Ag-(40-x)Cu-xIn and Ag- (40-x)Cu-xSn (x=5, 10, 15, 20, 25) alloys were used as brazing filler materials. A mild-steel square plate (S45C (JIS); side: 30 mm; thickness: 3mm) was employed as the substrate. A few surfaces with varying roughness were prepared using emery paper. Brazing filler material and metallic base plate were first washed with acetone, and then a flux was applied to them. The filler, 50 mg, was placed on the center of the metallic base with the flux. A spreading test was performed under Ar gas using an electrically heated furnace, after which, the original spreading area, defined as the sessile drop area, and the apparent spreading area, produced by the capillary grooves, were both evaluated. It was observed that the spreading area decreased with increasing In and Sn content.

Shrinkage-stress kinetics of photopolymerised resin-composites

NASA Astrophysics Data System (ADS)

Satterthwaite, Julian D.

The use of directly-placed substances as restorative materials in teeth remains the technique of choice for preserving function and form in teeth that have cavities. The current aesthetic restorative materials of choice are resin-composite materials, although these undergo molecular densification during polymerisation, which has deleterious effects. Although shrinkage-strain is the cause, it is the shrinkage-stress effects that may be seen as being responsible for the problems with adhesive resin-based restorations that are encountered clinically, the bond may fail with separation of the material from the cavity wall, leading to marginal discolouration, pulpal irritation and subsequent necrosis, post operative sensitivity, recurrent caries and eventual failure of restorations. Other outcomes include cohesive fracture of enamel or cusps, cuspal movement (strain) and persistent pain. The aims of this research were to characterise the effects of variations in resin-composite formulation on shrinkage-strain and shrinkage-stress kinetics. In particular, the influence of the size and morphology of the dispersed phase was investigated through the study of experimental formulations. Polymerisation shrinkage-strain kinetics were assessed with the bonded-disk method. It was found that resin-composites with spherical filler particles had significantly lower shrinkage-strain compared to those with irregular filler particles. Additionally, shrinkage-strain was found to be dependent on the size of filler particle, and this trend was related, in part, to differences in the degree of conversion. The data were also used to calculate the activation energy for each material, and a relationship between this and filler particle size for the irregular fillers was demonstrated. A fixed-compliance cantilever beam instrument (Bioman) was used for characterisation of shrinkage-stress kinetics. Significant differences were identified between materials in relation to filler particle size and morphology. A hypothesis for these interactions, relating to surface area effects, was presented. The complex interactions leading to the development of shrinkage-stress were investigated further. Shrinkage-stress over a 24 hour period was assessed, and modelled through application of the Kohlrausch-Williams-Watts equation. The effect of variation in specimen dimensions were assessed, and it was shown that the relationship of the specimen height and diameter to shrinkage-stress is a function not only of the C-factor (the ratio of bonded to unbonded surfaces), but also how the C-factor is created. These relationships were characterised and descriptive equations fitted to the data to describe the phenomena. Shrinkage-stress measurements against a variety of test surfaces were also assessed, and the use of stainless steel as a test surface was validated. Finally, exploratory research was undertaken to develop a moire interferometer for the measurement of in-plane displacements and strain arising in teeth due to polymerisation of resin-composite restorations.

The mechanical properties of nanofilled resin-based composites: characterizing discrete filler particles and agglomerates using a micromanipulation technique.

PubMed

Curtis, Andrew R; Palin, William M; Fleming, Garry J P; Shortall, Adrian C C; Marquis, Peter M

2009-02-01

To assess the mechanical properties of discrete filler particles representative of several inorganic fillers in modern dental resin-based composites (RBCs) and to assess the validity of a novel micromanipulation technique. RBCs with microhybrid (Filtek Z250), 'nanohybrid' (Grandio) and 'nanofilled' (Filtek Supreme), filler particle morphologies were investigated. Filler particles were provided by the manufacturer or separated from the unpolymerized resin using a dissolution technique. Filler particles (n=30) were subjected to compression using a micromanipulation technique between a descending glass probe and a glass slide. The number of distinct fractures particles underwent was determined from force/displacement and stress/deformation curves and the force at fracture and pseudo-modulus of stress was calculated. Agglomerated fillers ('nanoclusters') exhibited up to four distinct fractures, while spheroidal and irregular particles underwent either a single fracture or did not fracture following micromanipulation. Z-tests highlighted failure of nanoclusters to be significant compared with spheroidal and irregular particles (P<0.05). The mean force at first fracture of the nanoclusters was greater (1702+/-909 microN) than spheroidal and irregular particles (1389+/-1342 and 1356+/-1093 microN, respectively). Likewise, the initial pseudo-modulus of stress of nanoclusters (797+/-555 MPa) was also greater than spheroidal (587+/-439 MPa) or irregular (552+/-275 MPa) fillers. The validity of employing the micromanipulation technique to determine the mechanical properties of filler particulates was established. The 'nanoclusters' exhibited a greater tendency to multiple fractures compared with conventional fillers and possessed a comparatively higher variability of pseudo-modulus and load prior to and at fracture, which may modify the damage tolerance of the overall RBC system.

Performance of solvent-borne intumescent fire protective coating with Palm oil clinker as novel bio-filler on steel

NASA Astrophysics Data System (ADS)

Mustapa, S. A. S.; Ramli Sulong, N. H.

2017-06-01

This research deals with contribution of hybrid fillers with palm oil clinker (POC) as a novel bio-filler in solvent-borne intumescent fire protective coating for steel. The hybrid fillers with POC were mixed in appropriate amount of additives and acrylic binder to produce the intumescent coatings. The intumescent coatings were characterized by using Bunsen burner test, surface spread of flame, thermogravimetric analysis, field emission scanning electron microscopy, static immersion and Instron micro tester equipment. Specimen with POC as a single filler has significantly enhanced the fire protection performances of the intumescent coating due to the high thermal stability of POC, where less than 10% of temperature different when compared to specimens with hybrid fillers. From the flame spread classification, class 1 is the best classification while Class 4 is the worst and considered high risk. All specimens was classified as class 1 since the final spread of flame was less than 165 mm. For hybrid fillers composition, specimen consist of POC/Al(OH)3/TiO2 has significantly improved the water resistance of the coating due to the low solubility of Al(OH)3 in water, while specimen contain of Mg(OH)2 had higher mechanical strength due to the strong bonding between the metal surface and acrylic binder/Mg(OH)2 filler. It was found that coating with the incorporation of all hybrid fillers gives excellent fire protection performance with good thermal stability, water resistance and mechanical properties. It can be concluded that, the selection of appropriate composition of fillers and binder in intumescent coating was highly influence the intumescent coating performance.

Investigation of the degradation-retarding effect caused by the low swelling capacity of a novel hyaluronic Acid filler developed by solid-phase crosslinking technology.

PubMed

Park, Sunyoung; Park, Kui Young; Yeo, In Kwon; Cho, Sung Yeon; Ah, Young Chang; Koh, Hyun Ju; Park, Won Seok; Kim, Beom Joon

2014-06-01

A variety of hyaluronic acid (HA) fillers demonstrate unique physical characteristics, which affect the quality of the HA filler products. The critical factors that affect the degradation of HA gels have not yet been determined. Our objective was to determine the characteristics of HA gels that affect their resistance to the degradation caused by radicals and enzymes. Three types of HA fillers for repairing deep wrinkles, Juvederm Ultra Plus (J-U), Restylane Perlane (Perlane), and Cleviel, were tested in this study. The resistance of these HA fillers to enzymatic degradation was measured by carbazole and displacement assays using hyaluronidase as the enzyme. The resistance of these fillers to radical degradation was measured by the displacement assay using H2O2. Different tests for evaluating the degradation resistance of HA gels can yield different results. The filler most susceptible to enzymatic degradation was J-U, followed by Perlane and Cleviel. The HA filler showing the highest degree of degradation caused by H2O2 treatment was Perlane, followed by J-U, and then Cleviel. Cleviel showed higher enzymatic and radical resistances than J-U and Perlane did. Furthermore, it exhibited the highest resistance to heat and the lowest swelling ratio among all the fillers that were examined. The main factor determining the degradation of HA particles is the gel swelling ratio, which is related to the particle structure of the gel. Our in vitro assays suggest that the decrease in the swelling ratio will lead to a retarding effect on the degradation of HA fillers.

Investigation on mechanical properties of welded material under different types of welding filler (shielded metal arc welding)

NASA Astrophysics Data System (ADS)

Tahir, Abdullah Mohd; Lair, Noor Ajian Mohd; Wei, Foo Jun

2018-05-01

The Shielded Metal Arc Welding (SMAW) is (or the Stick welding) defined as a welding process, which melts and joins metals with an arc between a welding filler (electrode rod) and the workpieces. The main objective was to study the mechanical properties of welded metal under different types of welding fillers and current for SMAW. This project utilized the Design of Experiment (DOE) by adopting the Full Factorial Design. The independent variables were the types of welding filler and welding current, whereas the other welding parameters were fixed at the optimum value. The levels for types of welding filler were by the models of welding filler (E6013, E7016 and E7018) used and the levels for welding current were 80A and 90A. The responses were the mechanical properties of welded material, which include tensile strength and hardness. The experiment was analyzed using the two way ANOVA. The results prove that there are significant effects of welding filler types and current levels on the tensile strength and hardness of the welded metal. At the same time, the ANOVA results and interaction plot indicate that there are significant interactions between the welding filler types and the welding current on both the hardness and tensile strength of the welded metals, which has never been reported before. This project found that when the amount of heat input with increase, the mechanical properties such as tensile strength and hardness decrease. The optimum tensile strength for welded metal is produced by the welding filler E7016 and the optimum of hardness of welded metal is produced by the welding filler E7018 at welding current of 80A.

Biopolymer-based nanocomposites: effect of lignin acetylation in cellulose triacetate films

PubMed Central

Nevárez, Laura Alicia Manjarrez; Casarrubias, Lourdes Ballinas; Celzard, Alain; Fierro, Vanessa; Muñoz, Vinicio Torres; Davila, Alejandro Camacho; Lubian, José Román Torres; Sánchez, Guillermo González

2011-01-01

We have prepared all-biopolymer nanocomposite films using lignin as a filler and cellulose triacetate (CTA) as a polymer matrix, and characterized them by several analytical methods. Three types of lignin were tested: organosolv, hydrolytic and kraft, with or without acetylation. They were used in the form of nanoparticles incorporated at 1 wt% in CTA. Self-supported films were prepared by vapor-induced phase separation at controlled temperature (35–55 °C) and relative humidity (10–70%). The efficiency of acetylation of each type of lignin was studied and discussed, as well as its effects on film structure, homogeneity and mechanical properties. The obtained results are explained in terms of intermolecular filler-matrix interaction at the nanometer scale, for which the highest mechanical resistance was reached using hydrolytic lignin in the nanocomposite. PMID:27877425

Heat-Storage Modules Containing LiNO3-3H2O and Graphite Foam

NASA Technical Reports Server (NTRS)

Bootle, John

2008-01-01

A heat-storage module based on a commercial open-cell graphite foam (Poco-Foam or equivalent) imbued with lithium nitrate trihydrate (LiNO3-3H2O) has been developed as a prototype of other such modules for use as short-term heat sources or heat sinks in the temperature range of approximately 28 to 30 C. In this module, the LiNO3-3H2O serves as a phase-change heat-storage material and the graphite foam as thermally conductive filler for transferring heat to or from the phase-change material. In comparison with typical prior heat-storage modules in which paraffins are the phase-change materials and aluminum fins are the thermally conductive fillers, this module has more than twice the heat-storage capacity per unit volume.

Effect of filler loading of characteristic natural rubber latex (NRL) film filled with nanocrystal cellulose (NCC) and dipersion agent polyvinylpyrrolidone (PVP)

NASA Astrophysics Data System (ADS)

Harahap, Hamidah; Lubis, Yuni Aldriani; Taslim, Iriany, Nasution, Halimatuddahliana; Agustini, Hamda Eka

2018-04-01

A study has been conducted on the effect of filler loading on NRL films filled with NCC from corn cob waste. This study reviews on the filler loading of NRL film characteristics. The process begins with the production of NCC filler and then proceed with the production NRL film which is processed by coagulant dipping method. NRL is filled with NCC and PVP as dispersion agent of 2, 4, 3, 8 grams (filler loading) and 1% PVP by weight. The production of NRL film started with pre-vulcanization process at 70 °C and followed by vulcanization process at 110 °C for 20 minutes. The results showed that higher filler loading improved the higher crosslink density and mechanical properties of NRL film.

Microvascular complications associated with injection of cosmetic facelift dermal fillers

NASA Astrophysics Data System (ADS)

Yousefi, Siavash; Prendes, Mark; Chang, Shu-Hong; Wang, Ruikang K.

2015-02-01

Minimally-invasive cosmetic surgeries such as injection of subdermal fillers have become very popular in the past decade. Although rare, some complications may follow injections such as tissue necrosis and even blindness. There exist two hypothesis regarding source of these complications both of which include microvasculature. The first hypothesis is that fillers in between the tissue structures and compress microvasculature that causes blockage of tissue neutrition and oxygen exchange in the tissue. In another theory, it is hypothesized that fillers move inside major arteries and block the arteries/veins. In this paper, we study these hypotheses using optical coherence tomography and optical microangiography technologies with different hyaluronic-acid fillers in a mouse ear model. Based on our observations, the fillers eventually block arteries/veins if injected directly into them that eventually causes tissue necrosis.

Characterization of electron-beam-modified surface coated clay fillers and their influence on physical properties of rubbers

NASA Astrophysics Data System (ADS)

Ray, Sudip; Bhowmick, Anil K.; Sarma, K. S. S.; Majali, A. B.; Tikku, V. K.

2002-12-01

A novel process of surface modification of clay filler has been developed by coating this with an acrylate monomer, trimethylol propane triacrylate (TMPTA) or a silane coupling agent, triethoxy vinyl silane (TEVS) followed by electron beam irradiation. Characterization of these surface modified fillers has been carried out by Fourier-transform infrared analysis (FTIR), electron spectroscopy for chemical analysis (ESCA), wettability by dynamic wicking method measuring the rise of a liquid through a filler-packed capillary tube and water flotation test, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), thermogravimetric analysis (TGA), and X-ray diffraction (XRD). Presence of the acrylate and the silane coupling agent on the modified fillers has been confirmed from FTIR, ESCA, and EDX studies, which has also been supported by TGA studies. The contact angle measurement by dynamic wicking method suggests improvement in hydrophobicity of the treated fillers, which is supported by water flotation test especially in the case of silanized clay. However, XRD studies demonstrate that the entire modification process does not affect the bulk properties of the fillers. Finally, both unmodified and modified clay fillers have been incorporated in styrene butadiene rubber (SBR) and nitrile rubber (NBR). Rheometric and mechanical properties reveal that there is a definite improvement using these modified fillers specially in the case of silanized clay compared to the control sample, probably due to successful enhancement in interaction between the treated clay and the base polymer.

Degradation kinetics of ethylene-octene copolymer/wood flour biocomposites in dependence to filler content

NASA Astrophysics Data System (ADS)

Zykova, A. K.; Pantyukhov, P. V.; Monakhova, T. V.; Popov, A. A.

2017-06-01

This article is focused on thermal oxidative degradation and biodegradation in soil of biocomposites based on ethylene-octene copolymer (EOC), filled by wood flour (from 30 to 70% wt.), in dependence to the filler content. The study of oxidative degradation of composites was carried out at two temperatures (80 and 130°C respectively). The induction period and the rates of oxidation were determined. It was concluded that as filler content raises, the induction period increases. It can be explained by the higher specific area of composites in comparison with pure EOC. However, high filled composites (60 and 70 % of the filler) are oxidized with a huge induction period because polyphenols in the filler inhibit the oxidation process. Biodegradation test under laboratory conditions was carried out to investigate the biodegradability of the material. Composites with lower filler content have lower weight loss rate. Small particles are capsulated by polymer and are isolated from moisture and microorganisms. On the other hand, at a high filling of the composite small particles stick together and act as large ones. Such filler agglomerates are connected with each other and allow microorganisms to penetrate into the composite. It was concluded as filler content raises the mass loss increases.

Thermal conductivity of 2D nano-structured graphitic materials and their composites with epoxy resins

NASA Astrophysics Data System (ADS)

Mu, Mulan; Wan, Chaoying; McNally, Tony

2017-12-01

The outstanding thermal conductivity (λ) of graphene and its derivatives offers a potential route to enhance the thermal conductivity of epoxy resins. Key challenges still need to be overcome to ensure effective dispersion and distribution of 2D graphitic fillers throughout the epoxy matrix. 2D filler type, morphology, surface chemistry and dimensions are all important factors in determining filler thermal conductivity and de facto the thermal conductivity of the composite material. To achieve significant enhancement in the thermal conductivity of epoxy composites, different strategies are required to minimise phonon scattering at the interface between the nano-filler and epoxy matrix, including chemical functionalisation of the filler surfaces such that interactions between filler and matrix are promoted and interfacial thermal resistance (ITR) reduced. The combination of graphitic fillers with dimensions on different length scales can potentially form an interconnected multi-dimensional filler network and, thus contribute to enhanced thermal conduction. In this review, we describe the relevant properties of different 2D nano-structured graphitic materials and the factors which determine the translation of the intrinsic thermal conductivity of these 2D materials to epoxy resins. The key challenges and perspectives with regard achieving epoxy composites with significantly enhanced thermal conductivity on addition of 2D graphitic materials are presented.

Property of filler-loaded magnetic ferrite from plastic waste bottle used to treat municipal domestic sewage.

PubMed

Zhao, Ru-Jin; Gong, Li-Ying; Zhu, Hai-Dong; Liu, Qiao; Xu, Li-Xia; Lu, Lu; Yang, Qi-Zhi

2018-06-01

The present work investigates the properties of self-made magnetic filler from plastic waste bottle and explores a new technology approach of waste plastic resource utilization. The magnetic filler was prepared by air plasma modification and loading magnetic ferrite on the plastic strip from waste plastic bottle. The surface properties of magnetic filler were characterized by Atomic Force Microscope (AFM), contact angle system and Fourier Transform Infrared (FTIR). AFM images of original and modified plastic strip showed that low-temperature plasma treatment markedly increased the surface roughness of plastic strip. The mean roughness (Ra) of plastic strip rose from 1.116 to 5.024 nm. FTIR spectra indicated that a lot of polar oxygenic groups were introduced onto the surface of plastic by plasma modification. Modification by low-temperature plasma increased the hydrophilicity of plastic strip surface. When treatment time is 40 s, water contact angle of plastic strip surface reduced from 78.2° of original plastic strip to 25.3°. When used in bioreactor, magnetic filler had very favorable microenvironment for microorganism growth. Magnetic filler was more efficient for removing chemical oxygen demand (COD) and [Formula: see text] in sewage than nonmagnetic filler. The resource utilization of plastic wastes will become reality if the magnetic filler is applied widely.

The use of polyimide-modified aluminum nitride fillers in AlN@PI/Epoxy composites with enhanced thermal conductivity for electronic encapsulation

PubMed Central

Zhou, Yongcun; Yao, Yagang; Chen, Chia-Yun; Moon, Kyoungsik; Wang, Hong; Wong, Ching-ping

2014-01-01

Polymer modified fillers in composites has attracted the attention of numerous researchers. These fillers are composed of core-shell structures that exhibit enhanced physical and chemical properties that are associated with shell surface control and encapsulated core materials. In this study, we have described an apt method to prepare polyimide (PI)-modified aluminum nitride (AlN) fillers, AlN@PI. These fillers are used for electronic encapsulation in high performance polymer composites. Compared with that of untreated AlN composite, these AlN@PI/epoxy composites exhibit better thermal and dielectric properties. At 40 wt% of filler loading, the highest thermal conductivity of AlN@PI/epoxy composite reached 2.03 W/mK. In this way, the thermal conductivity is approximately enhanced by 10.6 times than that of the used epoxy matrix. The experimental results exhibiting the thermal conductivity of AlN@PI/epoxy composites were in good agreement with the values calculated from the parallel conduction model. This research work describes an effective pathway that modifies the surface of fillers with polymer coating. Furthermore, this novel technique improves the thermal and dielectric properties of fillers and these can be used extensively for electronic packaging applications. PMID:24759082

Development of sputtered techniques for thrust chambers, task 1. [evaluation of filler materials for regeneratively cooled thrust chambers

NASA Technical Reports Server (NTRS)

Mullaly, J. R.; Schmid, T. E.; Hecht, R. J.

1974-01-01

Filler materials proposed for use in the sputter fabrication regeneratively cooled thrust chambers were evaluated. Low melting castable alloys, CERROBEND. CERROCAST, and CERROTRU, slurry applied SERMETEL 481 and flame-sprayed aluminum were investigated as filler materials. Sputter deposition from a cylindrical cathode inverted magnestron was used to apply an OFHC copper closeout layer to filled OFHC copper ribbed-wall cylindrical substrates. The sputtered closeout layer structure was evaluated with respect to filler material contamination, predeposition machining and finishing operations, and deposition parameters. The application of aluminum by flame-spraying resulted in excessiver filler porosity. Though the outgassing from this porosity was found to be detrimental to the closeout layer structure, bond strengths in excess of 10,500 psi were achieved. Removal of the aluminum from the grooves was readily accomplished by leaching in a 7.0 molar solution of sodium hydroxide at 353 K. Of the other filler materials evaluated, CERROTRU was found to be the most suitable material with respect to completely filling the ribbed-wall cylinders and vacuum system compatibility. However, bond contamination resulted in low closeout layer bond strength with the CERROTRU filler. CERROBEND, CERROCAST, and SERMETEL 481 were found to be unacceptable as filler materials.

Filler metal alloy for welding cast nickel aluminide alloys

DOEpatents

Santella, M.L.; Sikka, V.K.

1998-03-10

A filler metal alloy used as a filler for welding cast nickel aluminide alloys contains from about 15 to about 17 wt. % chromium, from about 4 to about 5 wt. % aluminum, equal to or less than about 1.5 wt. % molybdenum, from about 1 to about 4.5 wt. % zirconium, equal to or less than about 0.01 wt. % yttrium, equal to or less than about 0.01 wt. % boron and the balance nickel. The filler metal alloy is made by melting and casting techniques such as are melting the components of the filler metal alloy and cast in copper chill molds. 3 figs.

Improvement of Scratch and Wear Resistance of Polymers by Fillers Including Nanofillers

PubMed Central

Brostow, Witold; Lobland, Haley E. Hagg; Hnatchuk, Nathalie; Perez, Jose M.

2017-01-01

Polymers have lower resistance to scratching and wear than metals. Liquid lubricants work well for metals but not for polymers nor for polymer-based composites (PBCs). We review approaches for improvement of tribological properties of polymers based on inclusion of fillers. The fillers can be metallic or ceramic—with obvious consequences for electrical resistivity of the composites. Distinctions between effectiveness of micro- versus nano-particles are analyzed. For example, aluminum nanoparticles as filler are more effective for property improvement than microparticles at the same overall volumetric concentration. Prevention of local agglomeration of filler particles is discussed along with a technique to verify the prevention. PMID:28336900

Characterization of carbon silica hybrid fillers obtained by pyrolysis of waste green tires by the STEM–EDX method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Al-Hartomy, Omar A.; Department of Physics, Faculty of Science, University of Tabuk, Tabuk 71491; Al-Ghamdi, Ahmed A.

2015-03-15

Dual phase carbon–silica hybrid fillers obtained by pyrolysis-cum-water vapor of waste green tires have been characterized by energy dispersive X-ray spectroscopy in a scanning transmission electron microscope, silicate analysis, weight analysis, atomic absorption spectroscopy and by inductively coupled plasma–optical emission spectroscopy. The results achieved have shown that the location and distribution of the phases in the carbon silica hybrid fillers as well as their most essential characteristics are influenced by the pyrolysis conditions. The carbon phase of the filler thus obtained is located predominantly in the space among silica aggregates which have already been existing while it has been formedmore » by elastomer destruction in the course of pyrolysis. The presence of ZnS also has been found in the hybrid fillers investigated. - Highlights: • Dual phase fillers obtained by pyrolysis of waste green tires have been characterized. • The STEM–EDX method was used for characterization. • The phase distributions in the fillers are influenced by the pyrolysis conditions.« less

Wide gap active brazing of ceramic-to-metal-joints for high temperature applications

NASA Astrophysics Data System (ADS)

Bobzin, K.; Zhao, L.; Kopp, N.; Samadian Anavar, S.

2014-03-01

Applications like solid oxide fuel cells and sensors increasingly demand the possibility to braze ceramics to metals with a good resistance to high temperatures and oxidative atmospheres. Commonly used silver based active filler metals cannot fulfill these requirements, if application temperatures higher than 600°C occur. Au and Pd based active fillers are too expensive for many fields of use. As one possible solution nickel based active fillers were developed. Due to the high brazing temperatures and the low ductility of nickel based filler metals, the modification of standard nickel based filler metals were necessary to meet the requirements of above mentioned applications. To reduce thermally induced stresses wide brazing gaps and the addition of Al2O3 and WC particles to the filler metal were applied. In this study, the microstructure of the brazed joints and the thermo-chemical reactions between filler metal, active elements and WC particles were analyzed to understand the mechanism of the so called wide gap active brazing process. With regard to the behavior in typical application oxidation and thermal cycle tests were conducted as well as tensile tests.

Effect of filler content on mechanical and dynamic mechanical properties of particulate biphasic calcium phosphate--polylactide composites.

PubMed

Bleach, N C; Nazhat, S N; Tanner, K E; Kellomäki, M; Törmälä, P

2002-04-01

A bioabsorbable self-reinforced polylactide/biphasic calcium phosphate (BCP) composite is being developed for fracture fixation plates. One manufacturing route is to produce preimpregnated sheets by pulling polylactide (PLA) fibres through a suspension of BCP filler in a PLA solution and compression moulding the prepreg to the desired shape. To aid understanding of the process, interactions between the matrix and filler were investigated. Composite films containing 0-0.25 volume fraction filler, produced by solvent casting, were analysed using SEM, tensile testing and dynamic mechanical analysis (DMA). Homogeneous films could be made, although some particle agglomeration was seen at higher filler volume fractions. As the filler content increased, the failure strain decreased due to a reduction in the amount of ductile polymer present and the ultimate tensile strength (UTS) decreased because of agglomeration and void formation at higher filler content. The matrix glass transition temperature increased due to polymer chain adsorption and immobilization onto the BCP particles. Complex damping mechanisms, such as particle-particle agglomeration, may exist at the higher BCP volume fractions.

Development of a novel oxirane-acrylate composite restorative resin material

NASA Astrophysics Data System (ADS)

Sripathi Panditaradhyula, Anuhya

The need for resin with a long clinical life can be satiated through the novel formulation of varying concentrations of oxirane and acrylate monomers with an increase in filler loading in the sample, which will allow the creation of a resin that is less susceptible to chemical degradation along with improved mechanical properties. Various concentrations of oxirane and acrylate monomers with a three-component photoinitiation system, which is capable of both free radical (acrylate) and cationic (oxirane) initiation, are used. The resin composites were placed in the Speedmixer for 30 seconds and gravitation convection oven for one minute, repeated 5-7 times. The resin composites were used to create a 9.525 mm diameter * 1.5875 mm thick resin mold. The mold was then photocured for twenty seconds on both sides using VALO blue LED light. The Rockwell hardness and shore D durometer hardness served as relative measures of bonding between the monomers. The ideal formulation of oxirane and acrylate concentrations were used to perform the Instron 3 point bend test, as well as contact angle determination. The goal is to identify a resin with a clinical life twice that of the resins being used in practice. Potential findings include ideal oxirane and acrylate concentrations with the highest shore D durometer hardness, Rockwell hardness, contact angle values, and Instron 3 point bend test values. Ideal color, transparency and properties of the resin are taken into account. Optimization of oxirane and acrylate monomers, impact while using various filler components (salination, number of fillers), filler particle size variations and variations in using different filler concentrations are observed. Results of using micro and nano-sized monomers are also studied. Addition of fluorinated acrylate monomer to the micro and nano composite was the next goal. A comparison of all the above stated compositions to the control group 70/30 BisTEG was done. A study on the degradation behavior of these specimens were done by placing the respective specimens in distilled water, ascorbic acid (pH=1.5) and NaOH (pH=13). These resins were not fully cured with filler apart from filled 25:75 oxirane: acrylate cured best. Replacing 4-(Octyloxy) phenyl] phenyl iodonium SbF6 (OPPI) with 4-Isopropyl-4'- methyldiphenyl iodonium Tetrakis (pentafluorophenyl borate (Borate) initiator enhanced 24hr oxirane cure. Formulations had greater hardness compared with the controls. The increase in hardness was due to Increase in oxirane functionality, Increase in filler loading and use of acrylate-salinated filler. Modulus and ultimate transverse strength are greater than controls, but did not have statistically significance energy to break. Thus, these composites are as tough as controls and less brittle. They have the higher hydrophobicity than BisGMA: TEGDMA controls. Furthermore, other means of increasing hydrophobicity was explored, because higher the hydrophobicity, higher the resistance to hydrolytic degradation. Further research observations, such as dynamic mechanical analysis, should be carried out in order to determine the molecular interactions and usage of multi-walled, white carbon nanotubes as filler material.

Development of a SMA-Based, Slat-Gap Filler for Airframe Noise Reduction

NASA Technical Reports Server (NTRS)

Turner, Travis L.; Long, David L.

2015-01-01

Noise produced by unsteady flow around aircraft structures, termed airframe noise, is an important source of aircraft noise during the approach and landing phases of flight. Conventional leading-edge-slat devices for high lift on typical transport aircraft are a prominent source of airframe noise. Many concepts for slat noise reduction have been investigated. Slat-cove fillers have emerged as an attractive solution, but they maintain the gap flow, leaving some noise production mechanisms unabated, and thus represent a nonoptimal solution. Drooped-leading-edge (DLE) concepts have been proposed as "optimal" because the gap flow is eliminated. The deployed leading edge device is not distinct and separate from the main wing in DLE concepts and the high-lift performance suffers at high angles of attack (alpha) as a consequence. Elusive high-alpha performance and excessive weight penalty have stymied DLE development. The fact that high-lift performance of DLE systems is only affected at high alpha suggests another concept that simultaneously achieves the high-lift of the baseline airfoil and the noise reduction of DLE concepts. The concept involves utilizing a conventional leading-edge slat device and a deformable structure that is deployed from the leading edge of the main wing and closes the gap between the slat and main wing, termed a slat-gap filler (SGF). The deployable structure consists of a portion of the skin of the main wing and it is driven in conjunction with the slat during deployment and retraction. Benchtop models have been developed to assess the feasibility and to study important parameters. Computational models have assisted in the bench-top model design and provided valuable insight in the parameter space as well as the feasibility.

Torrefied biomass-polypropylene composites

USDA-ARS?s Scientific Manuscript database

Torrefied almond shells and wood chips were incorporated into polypropylene as fillers to produce torrefied biomass-polymer composites. Response surface methodology was used to examine the effects of filler concentration, filler size, and lignin factor (relative lignin to cellulose concentration) on...

Injectable fillers: review of material and properties.

PubMed

Attenello, Natalie Huang; Maas, Corey S

2015-02-01

With an increasing understanding of the aging process and the rapidly growing interest in minimally invasive treatments, injectable facial fillers have changed the perspective for the treatment and rejuvenation of the aging face. Other than autologous fat and certain preformed implants, the collagen family products were the only Food and Drug Administration approved soft tissue fillers. But the overwhelming interest in soft tissue fillers had led to the increase in research and development of other products including bioengineered nonpermanent implants and permanent alloplastic implants. As multiple injectable soft tissue fillers and biostimulators are continuously becoming available, it is important to understand the biophysical properties inherent in each, as these constitute the clinical characteristics of the product. This article will review the materials and properties of the currently available soft tissue fillers: hyaluronic acid, calcium hydroxylapatite, poly-l-lactic acid, polymethylmethacrylate, and autologous fat (and aspirated tissue including stem cells). Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Improved TIG weld joint strength in aluminum alloy 2219-T87 by filler metal substitution

NASA Technical Reports Server (NTRS)

Poorman, R. M.; Lovoy, C. V.

1972-01-01

The results of an investigation on weld joint characteristics of aluminum alloy 2219-T87 are given. Five different alloys were utilized as filler material. The mechanical properties of the joints were determined at ambient and cryogenic temperatures for weldments in the as-welded condition and also, for weldments after elevated temperature exposures. Other evaluations included hardness surveys, stress corrosion susceptibility, and to a limited extent, the internal metallurgical weld structures. The overall results indicate that M-943 filler weldments are superior in strength to weldments containing either the standard 2319 filler or fillers 2014, 2020, and a dual wire feed consisting of three parts 2319 and one part 5652. In addition, no deficiencies were evident in M-934 filler weldments with regard to ductility, joint strength after elevated temperature exposure, weld hardness, metallographic structures, or stress corrosion susceptibility.

The disfluent discourse: Effects of filled pauses on recall

PubMed Central

Fraundorf, Scott H.; Watson, Duane G.

2011-01-01

We investigated the mechanisms by which fillers, such as uh and um, affect memory for discourse. Participants listened to and attempted to recall recorded passages adapted from Alice’s Adventures in Wonderland. The type and location of interruptions were manipulated through digital splicing. In Experiment 1, we tested a processing time account of fillers’ effects. While fillers facilitated recall, coughs matched in duration to the fillers impaired recall, suggesting that fillers’ benefits cannot be attributed to adding processing time. In Experiment 2, fillers’ locations were manipulated based on norming data to be either predictive or non-predictive of upcoming material. Fillers facilitated recall in both cases, inconsistent with an account in which listeners predict upcoming material using past experience with the distribution of fillers. Instead, these results suggest an attentional orienting account in which fillers direct attention to the speech stream but do not always result in specific predictions about upcoming material. PMID:21765590

PEDOT:PSS/GO nanocomposites: Determination of the aspect ratio by indirect measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Giuri, Antonella; Colella, Silvia; Listorti, Andrea

2016-05-18

Polymer nanocomposites properties significantly depend on the average size of the fillers dispersed into the matrix and on the grade of the dispersion, the latter influenced by the process techniques. In this work, we determined the aspect ratio of graphene oxide (GO) dispersed into Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), starting from the indirect measurement of the rheological behavior of polymer/filler mixtures, as a function of the shear rate and the volumetric composition. PEDOT:PSS+GO nanocomposite films were also realized by spin coating on different substrates and characterized by Scanning electron microscopy (SEM) and X-ray diffraction (XRD), in order to analyze the quality of themore » dispersion, even by direct measurements.« less

Thermal Analysis of Filler Reinforced Polymeric Composites

NASA Astrophysics Data System (ADS)

Ghadge, Mahesh Devidas

Improving heat dissipating property of composite materials is becoming increasingly important in domains ranging from the automotive industry, electronic devices to aeronautical industry. Effective heat dissipation is required especially in aircraft and racing tires to guarantee high performance and good service life [1]. The present study is focused on improving the thermal conductivity of Emulsion-styrene butadiene rubber (ESBR) which is a cheap alternative to other rubber composites. The disadvantages of ESBR are low thermal conductivity and high heat generation. Adding fillers with high thermal conductivity to ESBR is proposed as a technique for improving the thermal conductivity of ESBR. The purpose of the research is to predict the thermal conductivity of ESBR when filled with fillers of much higher thermal conductivity and also to find out to what extent the filler properties affect the heat transfer capabilities of the composite matrix. The influence of different filler shapes i.e. spherical, cylindrical and platelets on the overall thermal capability of composite matrix is studied, the finite element modelings are conducted using Abaqus. Three-dimensional and two-dimensional models are created in Abaqus to simulate the microstructure of the composite matrix filled with fillers. Results indicate that the overall thermal conductivity increases with increasing filler loading i.e. for a filler volume fraction of 0.27, the conductivity increased by around 50%. Filler shapes, orientation angle, and aspect ratio of the fillers significantly influences the thermal conductivity. Conductivity increases with increasing aspect ratio (length/diameter) of the cylindrical fillers since longer conductive chains are able to form at the same volume percentage as compared to spherical fillers. The composite matrix reaches maximum thermal conductivity when the cylindrical fillers are oriented in the direction of heat flow. The heat conductivity predicted by FEM for ESBR is compared with that predicted by mean field theories. At low volume fractions the FEM and mean field theory results are matching. However, at high volume fractions, the results obtained by the two methods are not in agreement. This is due to the fact that mean field theory do not consider the particle interactions happening at higher volume fractions. The present analysis can be used to tailor the thermal properties of ESBR for required thermal conductivity for a wide range of applications such as racing tires, electronic gadgets or aeronautical components. In addition, the proposed FEM models can be used to design and optimize the properties of new composite materials providing more insight into the thermal conductivity of composite polymers and aid in understanding heat transfer mechanism of reinforced polymers.

Why does starvation make bones fat?

PubMed

Devlin, Maureen J

2011-01-01

Body fat, or adipose tissue, is a crucial energetic buffer against starvation in humans and other mammals, and reserves of white adipose tissue (WAT) rise and fall in parallel with food intake. Much less is known about the function of bone marrow adipose tissue (BMAT), which are fat cells found in bone marrow. BMAT mass actually increases during starvation, even as other fat depots are being mobilized for energy. This review considers several possible reasons for this poorly understood phenomenon. Is BMAT a passive filler that occupies spaces left by dying bone cells, a pathological consequence of suppressed bone formation, or potentially an adaptation for surviving starvation? These possibilities are evaluated in terms of the effects of starvation on the body, particularly the skeleton, and the mechanisms involved in storing and metabolizing BMAT during negative energy balance. Copyright © 2011 Wiley-Liss, Inc.

Physicochemical and bioactive properties of innovative resin-based materials containing functional halloysite-nanotubes fillers.

PubMed

Degrazia, Felipe Weidenbach; Leitune, Vicente Castelo Branco; Takimi, Antonio Shigueaki; Collares, Fabrício Mezzomo; Sauro, Salvatore

2016-09-01

This study aimed to assess the degree of conversion, microhardness, solvent degradation, contact angle, surface free energy and bioactivity (e.g., mineral precipitation) of experimental resin-based materials containing, pure or triclosan-encapsulated, aluminosilicate-(halloysite) nanotubes. An experimental resin blend was prepared using bis-GMA/TEGDMA, 75/25wt% (control). Halloysite nanotubes (HNT) doped with or without triclosan (TCN) were first analyzed using transmission electron microscopy (TEM). HNT or HNT/TCN fillers were incorporated into the resin blend at different concentrations (5, 10, and 20wt%). Seven experimental resins were created and the degree of conversion, microhardness, solvent degradation and contact angle were assessed. Bioactive mineral precipitation induced by the experimental resins was evaluated through Raman spectroscopy and SEM-EDX. TEM showed a clear presence of TCN particles inside the tubular lumen and along the outer surfaces of the halloysite nanotubes. The degree of conversion, surface free energy, microhardness, and mineral deposition of polymers increased with higher amount of HNTs. Conversely, the higher the amount (20wt%) of TCN-loaded HNTs the lower the microhardness of the experimental resins. The incorporation of pure or TCN-loaded aluminosilicate-(halloysite) nanotubes into resin-based materials increase the bioactivity of such experimental restorative materials and promotes mineral deposition. Therefore, innovative resin-based materials containing functional halloysite-nanotube fillers may represent a valuable alternative for therapeutic minimally invasive treatments. Copyright © 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Testing COBOL Programs by Mutation. Volume I. Introduction to the CMS.1 System.

DTIC Science & Technology

1980-02-01

ALTER-OCCURS><SYMBOL TABLE location><code><x> where code = 0 means "add 1 to occurs", = 1 means "subtract 1 from occurs". 4 Insert a filler ( PIC X) in...REC. 31 01 OLD-REC. 32 03 FILLER PIC X. 33 03 OLD-KEY PIC X(12). 34 03 FILLER PIC X(67). 35S to NEdETF 36 RECORD CONTATS 90 CHARACTERS 37 LABEL RECORDS...ARE STANDARD 3S DATA RECORD IS NEd-REC. 39 01 NEd-REC. AO 03 FILLER PIC 1. Al 03 NEW-(FY PIC X(12). A2 03 FILLER PIC 1(6?). 43 ED PMTHR 44 RECORD

Mechanical and microwave absorbing properties of carbon-filled polyurethane.

PubMed

Kucerová, Z; Zajícková, L; Bursíková, V; Kudrle, V; Eliás, M; Jasek, O; Synek, P; Matejková, J; Bursík, J

2009-01-01

Polyurethane (PU) matrix composites were prepared with various carbon fillers at different filler contents in order to investigate their structure, mechanical and microwave absorbing properties. As fillers, flat carbon microparticles, carbon microfibers and multiwalled carbon nanotubes (MWNT) were used. The microstructure of the composite was examined by scanning electron microscopy and transmission electron microscopy. Mechanical properties, namely universal hardness, plastic hardness, elastic modulus and creep were assessed by means of depth sensing indentation test. Mechanical properties of PU composite filled with different fillers were investigated and the composite always exhibited higher hardness, elastic modulus and creep resistance than un-filled PU. Influence of filler shape, content and dispersion was also investigated.

Influence of third-body particles originating from bone void fillers on the wear of ultra-high-molecular-weight polyethylene

PubMed Central

Cowie, Raelene M; Carbone, Silvia; Aiken, Sean; Cooper, John J; Jennings, Louise M

2016-01-01

Calcium sulfate bone void fillers are increasingly being used for dead space management in infected arthroplasty revision surgery. The presence of these materials as loose beads close to the bearing surfaces of joint replacements gives the potential for them to enter the joint becoming trapped between the articulating surfaces; the resulting damage to cobalt chrome counterfaces and the subsequent wear of ultra-high-molecular-weight polyethylene is unknown. In this study, third-body damage to cobalt chrome counterfaces was simulated using particles of the calcium sulfate bone void fillers Stimulan® (Biocomposites Ltd., Keele, UK) and Osteoset® (Wright Medical Technology, TN, USA) using a bespoke rig. Scratches on the cobalt chrome plates were quantified in terms of their density and mean lip height, and the damage caused by the bone void fillers was compared to that caused by particles of SmartSet GMV PMMA bone cement (DePuy Synthes, IN, USA). The surface damage from Stimulan® was below the resolution of the analysis technique used; SmartSet GMV caused 0.19 scratches/mm with a mean lip height of 0.03 µm; Osteoset® led to a significantly higher number (1.62 scratches/mm) of scratches with a higher mean lip height (0.04 µm). Wear tests of ultra-high-molecular-weight polyethylene were carried out in a six-station multi-axial pin on plate reciprocating rig against the damaged plates and compared to negative (highly polished) and positive control plates damaged with a diamond stylus (2 µm lip height). The wear of ultra-high-molecular-weight polyethylene was shown to be similar against the negative control plates and those damaged with third-body particles; there was a significantly higher (p < 0.001) rate of ultra-high-molecular-weight polyethylene wear against the positive control plates. This study showed that bone void fillers of similar composition can cause varying damage to cobalt chrome counterfaces. However, the lip heights of the scratches were not of sufficient magnitude to increase the wear of ultra-high-molecular-weight polyethylene above that of the negative controls. PMID:27312481

The effect of filler addition and oven temperature to the antioxidant quality in the drying of Physalis angulata leaf extract obtained by subcritical water extraction

NASA Astrophysics Data System (ADS)

Susanti, R. F.; Natalia, Desy

2016-11-01

In traditional medicine, Physalis angulata which is well known as ceplukan in Indonesia, has been utilized to cure several diseases by conventional extraction in hot water. The investigation of the Swietenia mahagoni extract activity in modern medicine typically utilized organic solvents such as ethanol, methanol, chloroform and hexane in extraction. In this research, subcritical water was used as a solvent instead of organic solvent to extract the Pysalis angulata leaf part. The focus of this research was the investigation of extract drying condition in the presence of filler to preserve the quality of antioxidant in Swietenia mahagoni extract. Filler, which is inert, was added to the extract during drying to help absorb the water while protect the extract from exposure in heat during drying. The effects of filler types, concentrations and oven drying temperatures were investigated to the antioxidant quality covering total phenol and antioxidant activity. Aerosil and microcrystalline cellulose (MCC) were utilized as fillers with concentration was varied from 0-30 wt% for MCC and 0-15 wt% for aerosil. The oven drying temperature was varied from 40-60 oC. The results showed that compare to extract dried without filler, total phenol and antioxidant activity were improved upon addition of filler. The higher the concentration of filler, the better the antioxidant; however it was limited by the homogeneity of filler in the extract. Both of the variables (oven temperature and concentration) played an important role in the improvement of extract quality of Swietenia mahagoni leaf. It was related to the drying time which can be minimized to protect the deterioration of extract from heat. In addition, filler help to provide the powder form of extract instead of the typical extract form which is sticky and oily.

Iterative and variational homogenization methods for filled elastomers

NASA Astrophysics Data System (ADS)

Goudarzi, Taha

Elastomeric composites have increasingly proved invaluable in commercial technological applications due to their unique mechanical properties, especially their ability to undergo large reversible deformation in response to a variety of stimuli (e.g., mechanical forces, electric and magnetic fields, changes in temperature). Modern advances in organic materials science have revealed that elastomeric composites hold also tremendous potential to enable new high-end technologies, especially as the next generation of sensors and actuators featured by their low cost together with their biocompatibility, and processability into arbitrary shapes. This potential calls for an in-depth investigation of the macroscopic mechanical/physical behavior of elastomeric composites directly in terms of their microscopic behavior with the objective of creating the knowledge base needed to guide their bottom-up design. The purpose of this thesis is to generate a mathematical framework to describe, explain, and predict the macroscopic nonlinear elastic behavior of filled elastomers, arguably the most prominent class of elastomeric composites, directly in terms of the behavior of their constituents --- i.e., the elastomeric matrix and the filler particles --- and their microstructure --- i.e., the content, size, shape, and spatial distribution of the filler particles. This will be accomplished via a combination of novel iterative and variational homogenization techniques capable of accounting for interphasial phenomena and finite deformations. Exact and approximate analytical solutions for the fundamental nonlinear elastic response of dilute suspensions of rigid spherical particles (either firmly bonded or bonded through finite size interphases) in Gaussian rubber are first generated. These results are in turn utilized to construct approximate solutions for the nonlinear elastic response of non-Gaussian elastomers filled with a random distribution of rigid particles (again, either firmly bonded or bonded through finite size interphases) at finite concentrations. Three-dimensional finite element simulations are also carried out to gain further insight into the proposed theoretical solutions. Inter alia, we make use of these solutions to examine the effects of particle concentration, mono- and poly-dispersity of the filler particle size, and the presence of finite size interphases on the macroscopic response of filled elastomers. The solutions are found able to explain and describe experimental results that to date have been understood only in part. More generally, the solutions provide a robust tool to efficiently guide the design of filled elastomers with desired macroscopic properties. The homogenization techniques developed in this work are not limited to nonlinear elasticity, but can be readily utilized to study multi-functional properties as well. For demonstration purposes, we work out a novel exact solution for the macroscopic dielectric response of filled elastomers with interphasial space charges.

The effect of filler addition and oven temperature to the antioxidant quality in the drying of Physalis angulata fruit extract obtained by subcritical water extraction

NASA Astrophysics Data System (ADS)

Susanti, R. F.; Christianto, G.

2016-01-01

Physalis angulata or ceplukan is medicinal herb, which grows naturally in Indonesia. It has been used in traditional medicine to treat several diseases. It is also reported to have antimycobacterial, antileukemic, antipyretic. In this research, Pysalis angulata fruit was investigated for its antioxidant capacity. In order to avoid the toxic organic solvent commonly used in conventional extraction, subcritical water extraction method was used. During drying, filler which is inert was added to the extract. It can absorb water and change the oily and sticky form of extract to powder form. The effects of filler types, concentrations and drying temperatures were investigated to the antioxidant quality covering total phenol, flavonoid and antioxidant activity. The results showed that total phenol, flavonoid and antioxidant activity were improved by addition of filler because the drying time was shorter compared to extract without filler. Filler absorbs water and protects extract from exposure to heat during drying. The combination between high temperature and shorter drying time are beneficial to protect the antioxidant in extract. The type of fillers investigation showed that aerosil gave better performance compared to Microcrystalline Celullose (MCC).

Avoiding and Treating Blindness From Fillers: A Review of the World Literature.

PubMed

Beleznay, Katie; Carruthers, Jean D A; Humphrey, Shannon; Jones, Derek

2015-10-01

As the popularity of soft tissue fillers increases, so do the reports of adverse events. The most serious complications are vascular in nature and include blindness. To review the cases of blindness after filler injection, to highlight key aspects of the vascular anatomy, and to discuss prevention and management strategies. A literature review was performed to identify all the cases of vision changes from filler in the world literature. Ninety-eight cases of vision changes from filler were identified. The sites that were high risk for complications were the glabella (38.8%), nasal region (25.5%), nasolabial fold (13.3%), and forehead (12.2%). Autologous fat (47.9%) was the most common filler type to cause this complication, followed by hyaluronic acid (23.5%). The most common symptoms were immediate vision loss and pain. Most cases of vision loss did not recover. Central nervous system complications were seen in 23.5% of the cases. No treatments were found to be consistently successful in treating blindness. Although the risk of blindness from fillers is rare, it is critical for injecting physicians to have a firm knowledge of the vascular anatomy and to understand key prevention and management strategies.

FILLERS-Q: an instrument for assessing patient experiences after treatment with facial injectable soft tissue fillers.

PubMed

Sclafani, Anthony P; Pizzi, Laura; Jutkowitz, Eric; Mueller, Nancy; Jung, Matthew

2010-08-01

Patient-reported outcomes data are limited after injectable soft tissue filler treatment. Patient-reported outcome measures (PROMs) are becoming integral to medical practices in other specialties and will become so as well in facial plastic surgery. The obvious differences in types of disorders treated and the outcomes of primary importance seen between general medical/surgical and facial plastic surgery practices make institution of standard outcomes studies difficult in facial plastic surgery. However, understanding the patient's experience and satisfaction with treatment is essential to continue to provide excellent care to facial aesthetic patients. This article describes use of a new survey instrument, Facial Injectables: Longevity, Late and Early Reactions and Satisfaction Questionnaire (FILLERS-Q), in assessing patient response to facial injections of soft tissue fillers. FILLERS-Q is a 43-item questionnaire that captures patient demographics (4 items), patient satisfaction with treatment (10 items), procedure-related events (3 to 7 items), impact on relationships (9 to 15 items), and economic considerations related to dermal filler treatment (3 to 7 items). The results provide a "snapshot" of patients treated in an individual surgeon's practice. (c) Thieme Medical Publishers.

Three-body-wear resistance of the experimental composites containing filler treated with hydrophobic silane coupling agents.

PubMed

Nihei, Tomotaro; Dabanoglu, Alp; Teranaka, Toshio; Kurata, Shigeaki; Ohashi, Katsura; Kondo, Yukishige; Yoshino, Norio; Hickel, Reinhard; Kunzelmann, Karl-Heinz

2008-06-01

This paper evaluated the wear resistance of resin composite materials with fillers which were modified with a novel hydrophobic silane coupling agent. The novel silane coupling agent containing hydrophobic phenyl group 3-(3-methoxy-4-methacryloyloxyphenyl)propyltrimethoxysilane (p-MBS) was synthesized. The experimental light-cure hybrid composites containing 85wt% of filler modified with this silane were formulated. Twelve specimens were prepared for the three-body-wear test with the ACTA machine and the collected data were analyzed statistically using a one-way ANOVA and Tukey's multiple comparison test as the post hoc test. The wear of the composites containing fillers treated with p-MBS was significantly lower compared with the composite materials containing fillers pretreated with 3-methacryloyloxypropyltrimethoxysilane or the commercially composites (AP-X and ELS extra low shrinkage) after a wear test for 200,000 cycles (p<0.05). It is suggested that the resin composites containing fillers modified with the novel hydrophobic silane has high wear resistant, because of the coupling layers treated with this silane had an excellent affinity with the base resin and formed a highly hydrophobic layer on the filler surface.

7 CFR 58.514 - Container fillers.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Container fillers. 58.514 Section 58.514 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards....514 Container fillers. Shall comply with the 3-A Sanitary Standards for Equipment for Packaging Frozen...

Filler wire for aluminum alloys and method of welding

NASA Technical Reports Server (NTRS)

Bjorkman, Jr., Gerald W. O. (Inventor); Cho, Alex (Inventor); Russell, Carolyn K. (Inventor)

2003-01-01

A weld filler wire chemistry has been developed for fusion welding 2195 aluminum-lithium. The weld filler wire chemistry is an aluminum-copper based alloy containing high additions of titanium and zirconium. The additions of titanium and zirconium reduce the crack susceptibility of aluminum alloy welds while producing good weld mechanical properties. The addition of silver further improves the weld properties of the weld filler wire. The reduced weld crack susceptibility enhances the repair weldability, including when planishing is required.

Influence of Cellulose Nanofillers on the Rheological Properties of Polymer Electrolytes

NASA Astrophysics Data System (ADS)

El Kissi, Nadia; Alloin, Fannie; Dufresne, Alain; Sanchez, Jean-Yves; Bossard, Frédéric; D'Aprea, Alessandra; Leroy, Séverine

2008-07-01

In this study, nanocomposite polymer electrolytes, based on high molecular weight PEO were prepared from high aspect ratio natural cellulosic nanofillers. The thermomechanical behaviour of the resulting nanocomposites was investigated using differential scanning calorimetry, dynamic mechanical analysis and rheometrical measurements. The influence of entanglements versus percolation mechanism on the determination of the mechanical properties of the composite was also investigated. Shear rheometry of the unfilled PEO and related nanocomposites shows that the shear viscosity first decreases when the concentration in cellulose increases. Then typical suspension behaviour is obtained and the viscosity increases with the concentration. This observation is in agreement with DSC and DMA results and is explained in terms of polymer-filler interactions. Interactions between cellulose fillers, are responsible for the reinforcing effect above the melting temperature of the matrix, through the formation of a stiff network that is well predicted by a percolation concept.

Application of micro- and nanocrystalline cellulose

NASA Astrophysics Data System (ADS)

Sotnikova, Yu S.; Demina, T. S.; Istomin, A. V.; Goncharuk, G. P.; Grandfils, Ch; Akopova, T. A.; Zelenetskii, A. N.; Babayevsky, P. G.

2018-04-01

Micro- and nanocrystalline forms of cellulose were extracted from flax stalks and evaluated in terms of their applicability for various materials science tasks. It was revealed that both form of cellulose had anisometric morphology with length of 27.1 μm and 159 nm; diameter of 8.7 μm and 85 nm, respectively. They were used as reinforcing fillers for fabrication of composite films based on hydroxyethylcellulose. Film-forming and mechanical properties of the composite materials were significantly varied in dependence on filler content (0–10 wt.%) and size. As a second option of micro- and nanocrystalline cellulose application, a study of their effectiveness as stabilizing agents for oil/water Pickering emulsions was carried out. In contrast to micron-sized cellulose the nanocrystalline form appeared to be successful in the process of CH2Cl2/water interface stabilization and fabrication of polylactide microparticles via oil/water Pickering emulsion solvent evaporation technique.

Tuning Glass Transition in Polymer Nanocomposites with Functionalized Cellulose Nanocrystals through Nanoconfinement.

PubMed

Qin, Xin; Xia, Wenjie; Sinko, Robert; Keten, Sinan

2015-10-14

Cellulose nanocrystals (CNCs) exhibit impressive interfacial and mechanical properties that make them promising candidates to be used as fillers within nanocomposites. While glass-transition temperature (Tg) is a common metric for describing thermomechanical properties, its prediction is extremely difficult as it depends on filler surface chemistry, volume fraction, and size. Here, taking CNC-reinforced poly(methyl-methacrylate) (PMMA) nanocomposites as a relevant model system, we present a multiscale analysis that combines atomistic molecular dynamics (MD) surface energy calculations with coarse-grained (CG) simulations of relaxation dynamics near filler-polymer interfaces to predict composite properties. We discover that increasing the volume fraction of CNCs results in nanoconfinement effects that lead to an appreciation of the composite Tg provided that strong interfacial interactions are achieved, as in the case of TEMPO-mediated surface modifications that promote hydrogen bonding. The upper and lower bounds of shifts in Tg are predicted by fully accounting for nanoconfinement and interfacial properties, providing new insight into tuning these aspects in nanocomposite design. Our multiscale, materials-by-design framework is validated by recent experiments and breaks new ground in predicting, without any empirical parameters, key structure-property relationships for nanocomposites.

Shape Memory Polyurethane Materials Containing Ferromagnetic Iron Oxide and Graphene Nanoplatelets

PubMed Central

Urban, Magdalena

2017-01-01

Intelligent materials, such as memory shape polymers, have attracted considerable attention due to wide range of possible applications. Currently, intensive research is underway, in matters of obtaining memory shape materials that can be actuated via inductive methods, for example with help of magnetic field. In this work, an attempt was made to develop a new polymer composite—polyurethane modified with graphene nanoplates and ferromagnetic iron oxides—with improved mechanical properties and introduced magnetic and memory shape properties. Based on the conducted literature review, gathered data were compared to the results of similar materials. Obtained materials were tested for their thermal, rheological, mechanical and shape memory properties. Structure of both fillers and composites were also analyzed using various spectroscopic methods. The addition of fillers to the polyurethane matrix improved the mechanical and shape memory properties, without having a noticeable impact on thermal properties. As it was expected, the high content of fillers caused a significant change in viscosity of filled prepolymers (during the synthesis stage). Each of the studied composites showed better mechanical properties than the unmodified polyurethanes. The addition of magnetic particles introduced additional properties to the composite, which could significantly expand the functionality of the materials developed in this work. PMID:28906445

Structural deformation of 0.74Pb(Mg1/3Nb2/3)O3-0.26PbTiO3 single crystal in 1-3 composites due to interface stresses and poling procedure optimization

NASA Astrophysics Data System (ADS)

Wang, Chunying; Sun, Enwei; Liu, Yingchun; Zhang, Rui; Yang, Bin; Cao, Wenwu

2016-09-01

Interface stresses strongly influence the functional property of 1-3 piezoelectric composites. Using the translucent nature of (1 - x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 single crystals, we have studied stress distributions and domain configuration changes during poling inside the crystal rods by polarizing light microscopy and piezoresponse force microscopy. It was found that the interface stresses due to interaction with polymeric filler led a deformed rhombohedral phase and caused incomplete poling near rod-edges. Compared with "hard" epoxy (Epotek301) filler, "soft" epoxy (Stycast) filler showed weaker impact on the crystals rods and less influence on domain configurations. We also show that high temperature poling (70 °C) can substantially improve the piezoelectric coefficient of composites filled with hard epoxy due to creeping above the glass transition Tg. Analytic stress distribution equations based on cylinder rods were modified to explain the physical principle and to predict the stress distribution for square rods case, which was verified by finite element simulation to be accurate within 5%.

Polymethylmethacrylate dermal fillers: evaluation of the systemic toxicity in rats.

PubMed

Medeiros, C C G; Borghetti, R L; Nicoletti, N; da Silva, V D; Cherubini, K; Salum, F G; de Figueiredo, M A Z

2014-01-01

This study evaluated local and systemic reactions after an intravascular injection of polymethylmethacrylate (PMMA) at two concentrations in a murine model. Thirty rats were divided equally into three groups: 2% PMMA, 30% PMMA, and a control group (normal saline only injection). The filler was injected into the ranine vein. The rats were sedated at 7 and 90 days and a clinical evaluation performed. After euthanasia, the right lung, liver, and right kidney were removed, weighed, and microscopically analyzed. The submandibular lymph nodes and tongue were removed and examined microscopically. Serum was subjected to liver and kidney function tests. No groups showed clinical alterations. Microspheres were not observed at any distant organ. Two samples from the 2% PMMA group showed a local inflammatory response at day 7 and another two samples from the 30% PMMA group at day 90. The group injected with 30% PMMA presented higher levels of alanine aminotransferase (P = 0.047) after 90 days when compared with the other groups. The data obtained in this study demonstrate that intravascular injections of PMMA fillers show potential health risks such as chronic inflammation at the implantation site. Copyright © 2013 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Identifying the Constituents of and Transformations in Diatomaceous Earth and Polysiloxane Foams Through the Use of Electron Paramagnetic Resonance Spectroscopy

NASA Astrophysics Data System (ADS)

Blair, Michael; Muenchausen, Ross; Bennett, Bryan; Smith, James; Stephens, Thomas; Cooke, Wayne

2007-03-01

The chemical aging of polymeric materials is largely governed by the characteristics of the storage environment. For polysiloxane foams, the diatomaceous earth (DE) filler is a small component of the foam, but it plays a large role in the handling of water in the system. The DE filler can act as either a ``source'' or a ``sink'' for water via both chemical hydroxylation/ dehydroxylation and physical adsorption/ desorption processes, depending on the processing history and storage conditions. We have used electron paramagnetic resonance (EPR) spectroscopy to examine composite foam material as well as the DE filler alone. Intense, broad (400 Gauss) resonances were recorded at room temperature as a function of the microwave power at X-band frequency. The observed spectra have been assigned to the iron oxide compounds goethite, lepidocrocite, hematite, and magnetite based upon the measured EPR spectra of these minerals. As the presence or absence of free H2O and the temperature of processing and storage also affects the interconversion of these various iron oxides, we indicate how this process can be followed by monitoring changes in the EPR spectra.

Enhanced Thermo-Optical Switching of Paraffin-Wax Composite Spots under Laser Heating

PubMed Central

Said, Asmaa; Salah, Abeer; Abdel Fattah, Gamal

2017-01-01

Thermo-optical switches are of particular significance in communications networks where increasingly high switching speeds are required. Phase change materials (PCMs), in particular those based on paraffin wax, provide wealth of exciting applications with unusual thermally-induced switching properties, only limited by paraffin’s rather low thermal conductivity. In this paper, the use of different carbon fillers as thermal conductivity enhancers for paraffin has been investigated, and a novel structure based on spot of paraffin wax as a thermo-optic switch is presented. Thermo-optical switching parameters are enhanced with the addition of graphite and graphene, due to the extreme thermal conductivity of the carbon fillers. Differential Scanning Calorimetry (DSC) and Scanning electron microscope (SEM) are performed on paraffin wax composites, and specific heat capacities are calculated based on DSC measurements. Thermo-optical switching based on transmission is measured as a function of the host concentration under conventional electric heating and laser heating of paraffin-carbon fillers composites. Further enhancements in thermo-optical switching parameters are studied under Nd:YAG laser heating. This novel structure can be used in future networks with huge bandwidth requirements and electric noise free remote aerial laser switching applications. PMID:28772884

Enhanced Thermo-Optical Switching of Paraffin-Wax Composite Spots under Laser Heating.

PubMed

Said, Asmaa; Salah, Abeer; Fattah, Gamal Abdel

2017-05-12

Thermo-optical switches are of particular significance in communications networks where increasingly high switching speeds are required. Phase change materials (PCMs), in particular those based on paraffin wax, provide wealth of exciting applications with unusual thermally-induced switching properties, only limited by paraffin's rather low thermal conductivity. In this paper, the use of different carbon fillers as thermal conductivity enhancers for paraffin has been investigated, and a novel structure based on spot of paraffin wax as a thermo-optic switch is presented. Thermo-optical switching parameters are enhanced with the addition of graphite and graphene, due to the extreme thermal conductivity of the carbon fillers. Differential Scanning Calorimetry (DSC) and Scanning electron microscope (SEM) are performed on paraffin wax composites, and specific heat capacities are calculated based on DSC measurements. Thermo-optical switching based on transmission is measured as a function of the host concentration under conventional electric heating and laser heating of paraffin-carbon fillers composites. Further enhancements in thermo-optical switching parameters are studied under Nd:YAG laser heating. This novel structure can be used in future networks with huge bandwidth requirements and electric noise free remote aerial laser switching applications.

Characterization of Mg/Al butt joints welded by gas tungsten arc filling with Zn–29.5Al–0.5Ti filler metal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Fei; Wang, Hongyang; Liu, Liming, E-mail: liulm@dlut.edu.cn

2014-04-01

The multivariate alloying design of a welding joint is used in the Mg to Al welding process. A Zn–29.5Al–0.5Ti alloy is added as filler metal in gas tungsten arc welding of Mg and Al alloy joint based on the analysis of Al and Mg alloy characteristics. The tensile strength, microstructure, and phase constitution of the weld seam are analyzed. The formation of brittle and hard Mg–Al intermetallic compounds is avoided because of the effects of Zn, Al, and Ti. The average tensile strength of the joint is 148 MPa. Al{sub 3}Ti is first precipitated and functions as the nucleus ofmore » heterogeneous nucleation during solidification. Moreover, the precipitated Al–MgZn{sub 2} hypoeutectic phase exhibited a feather-like structure, which enhances the property of the Mg–Al dissimilar joint. - Highlights: • Mg alloy AZ31B and Al alloy 6061 are butt welded by fusion welding. • The effect of Ti in filler metal is investigated. • The formation of Mg–Al intermetallic compounds is avoided.« less

Shape Memory Polyurethane Materials Containing Ferromagnetic Iron Oxide and Graphene Nanoplatelets.

PubMed

Urban, Magdalena; Strankowski, Michał

2017-09-14

Intelligent materials, such as memory shape polymers, have attracted considerable attention due to wide range of possible applications. Currently, intensive research is underway, in matters of obtaining memory shape materials that can be actuated via inductive methods, for example with help of magnetic field. In this work, an attempt was made to develop a new polymer composite-polyurethane modified with graphene nanoplates and ferromagnetic iron oxides-with improved mechanical properties and introduced magnetic and memory shape properties. Based on the conducted literature review, gathered data were compared to the results of similar materials. Obtained materials were tested for their thermal, rheological, mechanical and shape memory properties. Structure of both fillers and composites were also analyzed using various spectroscopic methods. The addition of fillers to the polyurethane matrix improved the mechanical and shape memory properties, without having a noticeable impact on thermal properties. As it was expected, the high content of fillers caused a significant change in viscosity of filled prepolymers (during the synthesis stage). Each of the studied composites showed better mechanical properties than the unmodified polyurethanes. The addition of magnetic particles introduced additional properties to the composite, which could significantly expand the functionality of the materials developed in this work.

Adaptive polymeric nanomaterials utilizing reversible covalent and hydrogen bonding

NASA Astrophysics Data System (ADS)

Neikirk, Colin

Adaptive materials based on stimuli responsive and reversible bonding moieties are a rapidly developing area of materials research. Advances in supramolecular chemistry are now being adapted to novel molecular architectures including supramolecular polymers to allow small, reversible changes in molecular and nanoscale structure to affect large changes in macroscale properties. Meanwhile, dynamic covalent chemistry provides a complementary approach that will also play a role in the development of smart adaptive materials. In this thesis, we present several advances to the field of adaptive materials and also provide relevant insight to the areas of polymer nanocomposites and polymer nanoparticles. First, we have utilized the innate molecular recognition and binding capabilities of the quadruple hydrogen bonding group ureidopyrimidinone (UPy) to prepare supramolecular polymer nanocomposites based on supramolecular poly(caprolactone) which show improved mechanical properties, but also an increase in particle aggregation with nanoparticle UPy functionalization. We also present further insight into the relative effects of filler-filler, filler-matrix, and matrix-matrix interactions using a UPy side-chain functional poly(butyl acrylate). These nanocomposites have markedly different behavior depending on the amount of UPy sidechain functionality. Meanwhile, our investigations of reversible photo-response showed that coumarin functionality in polymer nanoparticles not only facilitates light mediated aggregation/dissociation behavior, but also provides a substantial overall reduction in particle size and improvement in nanoparticle stability for particles prepared by Flash NanoPrecipitation. Finally, we have combined these stimuli responsive motifs as a starting point for the development of multiresponsive adaptive materials. The synthesis of a library of multifunctional materials has provided a strong base for future research in this area, although our initial investigations were ultimately unsuccessful due to photodegradation of the UPy moiety in chloroform solution. This thesis has provided the Priestley lab with a solid base for the further investigation of the diverse applications and unsolved science of stimuli responsive adaptive materials.

Iatrogenic occlusion of the ophthalmic artery after cosmetic facial filler injections: a national survey by the Korean Retina Society.

PubMed

Park, Kyu Hyung; Kim, Yong-Kyu; Woo, Se Joon; Kang, Se Woong; Lee, Won Ki; Choi, Kyung Seek; Kwak, Hyung Woo; Yoon, Ill Han; Huh, Kuhl; Kim, Jong Woo

2014-06-01

Iatrogenic occlusion of the ophthalmic artery and its branches is a rare but devastating complication of cosmetic facial filler injections. To investigate clinical and angiographic features of iatrogenic occlusion of the ophthalmic artery and its branches caused by cosmetic facial filler injections. Data from 44 patients with occlusion of the ophthalmic artery and its branches after cosmetic facial filler injections were obtained retrospectively from a national survey completed by members of the Korean Retina Society from 27 retinal centers. Clinical features were compared between patients grouped by angiographic findings and injected filler material. Visual prognosis and its relationship to angiographic findings and injected filler material. Ophthalmic artery occlusion was classified into 6 types according to angiographic findings. Twenty-eight patients had diffuse retinal and choroidal artery occlusions (ophthalmic artery occlusion, generalized posterior ciliary artery occlusion, and central retinal artery occlusion). Sixteen patients had localized occlusions (localized posterior ciliary artery occlusion, branch retinal artery occlusion, and posterior ischemic optic neuropathy). Patients with diffuse occlusions showed worse initial and final visual acuity and less visual gain compared with those having localized occlusions. Patients receiving autologous fat injections (n = 22) had diffuse ophthalmic artery occlusions, worse visual prognosis, and a higher incidence of combined brain infarction compared with patients having hyaluronic acid injections (n = 13). Clinical features of iatrogenic occlusion of the ophthalmic artery and its branches following cosmetic facial filler injections were diverse according to the location and extent of obstruction and the injected filler material. Autologous fat injections were associated with a worse visual prognosis and a higher incidence of combined cerebral infarction. Extreme caution and care should be taken during these injections, and physicians should be aware of a diverse spectrum of complications following cosmetic facial filler injections.

Welding wire pressure sensor assembly

NASA Technical Reports Server (NTRS)

Morris, Timothy B. (Inventor); Milly, Peter F., Sr. (Inventor); White, J. Kevin (Inventor)

1994-01-01

The present invention relates to a device which is used to monitor the position of a filler wire relative to a base material being welded as the filler wire is added to a welding pool. The device is applicable to automated welding systems wherein nonconsumable electrode arc welding processes are utilized in conjunction with a filler wire which is added to a weld pool created by the electrode arc. The invention senses pressure deviations from a predetermined pressure between the filler wire and the base material, and provides electrical signals responsive to the deviations for actuating control mechanisms in an automatic welding apparatus so as to minimize the pressure deviation and to prevent disengagement of the contact between the filler wire and the base material.

14 CFR 25.973 - Fuel tank filler connection.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Fuel tank filler connection. 25.973 Section 25.973 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Fuel System § 25.973 Fuel tank filler...

14 CFR 29.973 - Fuel tank filler connection.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Fuel tank filler connection. 29.973 Section 29.973 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Fuel System § 29.973 Fuel tank filler...

14 CFR 29.973 - Fuel tank filler connection.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Fuel tank filler connection. 29.973 Section 29.973 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Fuel System § 29.973 Fuel tank filler...

14 CFR 25.973 - Fuel tank filler connection.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Fuel tank filler connection. 25.973 Section 25.973 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Fuel System § 25.973 Fuel tank filler...

14 CFR 25.973 - Fuel tank filler connection.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Fuel tank filler connection. 25.973 Section 25.973 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Fuel System § 25.973 Fuel tank filler...

14 CFR 29.973 - Fuel tank filler connection.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Fuel tank filler connection. 29.973 Section 29.973 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Fuel System § 29.973 Fuel tank filler...

14 CFR 29.973 - Fuel tank filler connection.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Fuel tank filler connection. 29.973 Section 29.973 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Fuel System § 29.973 Fuel tank filler...

14 CFR 25.973 - Fuel tank filler connection.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel tank filler connection. 25.973 Section 25.973 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Fuel System § 25.973 Fuel tank filler...

14 CFR 29.973 - Fuel tank filler connection.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel tank filler connection. 29.973 Section 29.973 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Fuel System § 29.973 Fuel tank filler...

14 CFR 25.973 - Fuel tank filler connection.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Fuel tank filler connection. 25.973 Section 25.973 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Fuel System § 25.973 Fuel tank filler...

Use of nut shells as fillers in polymer composites

USDA-ARS?s Scientific Manuscript database

The three nutshell fillers including walnut, almond and pistachio nutshell were added to PLA. All the physical properties of samples deteriorated relative to PLA. When subjected to heat pre-treatment, although the physical properties of PLA-filler samples still deteriorated, the extent of deteriorat...

Charcoal byproducts as potential styrene-butadiene rubber composte filler

USDA-ARS?s Scientific Manuscript database

Carbon black, a byproduct of the petroleum industry, is the world's most predominant filler for rubber composites. In this study, various renewable charcoals in the form of pyrolyzed agricultural byproducts were evaluted as potential carbon-based filler for rubber composites made with carboxylated s...

Evaluating Waste Charcoal as Potential Rubber Composite Filler

USDA-ARS?s Scientific Manuscript database

Carbon black, a byproduct of the petroleum industry, is the world's most predominant filler for rubber composites. In this study, charcoal in the form of pyrolyzed agricultural products was evaluated as potential carbon-based filler for rubber composites made with carboxylated styrene-butadiene lat...

Polyurethane Filler for Electroplating

NASA Technical Reports Server (NTRS)

Beasley, J. L.

1984-01-01

Polyurethane foam proves suitable as filler for slots in parts electroplated with copper or nickel. Polyurethane causes less contamination of plating bath and of cleaning and filtering tanks than wax fillers used previously. Direct cost of maintenance and indirect cost of reduced operating time during tank cleaning also reduced.

Facial soft-tissue fillers conference: assessing the state of the science.

PubMed

Rohrich, Rod J; Hanke, C William; Busso, Mariano; Carruthers, Alastair; Carruthers, Jean; Fagien, Steven; Fitzgerald, Rebecca; Glogau, Richard; Greenberger, Phyllis E; Lorenc, Z Paul; Marmur, Ellen S; Monheit, Gary D; Pusic, Andrea; Rubin, Mark G; Rzany, Berthold; Sclafani, Anthony; Taylor, Susan; Weinkle, Susan; McGuire, Michael F; Pariser, David M; Casas, Laurie A; Collishaw, Karen J; Dailey, Roger A; Duffy, Stephen C; Edgar, Elizabeth Jan; Greenan, Barbara L; Haenlein, Kelly; Henrichs, Ronald A; Hume, Keith M; Lum, Flora; Nielsen, David R; Poulsen, Lisle; Shoaf, Lori; Schoaf, Lori; Seward, William; Begolka, Wendy Smith; Stanton, Robert G; Svedman, Katherine J; Thomas, J Regan; Sykes, Jonathan M; Wargo, Carol; Weiss, Robert A

2011-04-01

: The American Society of Plastic Surgeons and the American Academy of Dermatology, with the support of other sister societies, conducted the Facial Soft-Tissue Fillers: Assessing the State of the Science conference in December of 2009. The American Society of Plastic Surgeons and the American Academy of Dermatology established a panel of leading experts in the field of soft-tissue fillers-from researchers to clinicians-and other stakeholders for the conference to examine and discuss issues of patient safety, efficacy, and effectiveness in relation to the approved and off-label use of soft-tissue fillers, and other factors, including the training and level of experience of individuals administering fillers. This report represents the systematic literature review that examines comprehensively the available evidence and gaps in the evidence related to soft-tissue fillers, to inform and support the work of the state-of-the-science conference panel. This evidence-based medicine review will serve as the foundation for future evidence-based medicine reports in this growing field.

Morphology-Property relationship of high density Polyethylene/Hevea Brasiliensis Leaves/Imperata cylindrica hybrid composite: Impact strength

NASA Astrophysics Data System (ADS)

Rashidi, A. R.; Muhammad, A.; Roslan, A.

2017-09-01

This research studies about the Hevea Brasiliensis Leaves and Imperata Cylindrica that was used as filler in High Density Polyethylene (HDPE). The fillers content were varied in the composite by 5 wt%, 15 wt% and 25 wt% respectively. This polymer composite are being studied by using Impact Test and Scanning Electron Microscopy (SEM). The analysis show that the impact strength value increased when the percent of bio filler used is low. The result between pure HDPE and the composites shows an outcome of significant changes in impact energy values, while the values between different composite change slightly. A composite that contained 5 wt% of fillers is the better energy absorber than 15 wt% and 25 wt% according to impact testing. In addition, the morphology studies on the composite sample show that the bio-filler was successfully embedded. Overall, these finding suggest that HBL and IC can be an alternative filler to be incorporated in polymer matrix.

Influence of reactive fillers on concrete corrosion resistance

NASA Astrophysics Data System (ADS)

Rakhimbayev, Sh M.; Tolypina, N. M.; Khakhaleva, E. N.

2018-03-01

Contact surfaces represent the weakest link in a conglomerate structure of materials. They ensure the diffusion of aggressive agents inside the material. To reduce the conductivity of contact surfaces it is advisable to use reactive fillers, which interact with cement matrix via certain mechanisms, which in turn, reduces the permeability of the contact layer and fosters durability of products. The interaction of reactive fillers with calcium hydroxide of a concrete liquid phase in a contact area leads to the formation of hydrated calcium silicates of a tobermorite group. Such compounds, being settled in pores and capillaries of a product, colmatage and clog them to some extent thus leading to diffusion delay (inhibition) with regard to aggressive components of external media inside porous material, which in turn inhibits the corrosion rate. The authors studied and compared the corrosion of cement concrete with a standard filler (quartz sand) and a reactive filler (perlite and urtit). The experiments confirmed the positive influence of active fillers on concrete corrosion resistance.

Inorganic/organic nanocomposites: Reaching a high filler content without increasing viscosity using core-shell structured nanoparticles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benhadjala, W., E-mail: warda.benhadjala@cea.fr; CEA, LETI, Minatec Campus, 38000 Grenoble; Gravoueille, M.

2015-11-23

Extensive research is being conducted on the development of inorganic/organic nanocomposites for a wide variety of applications in microelectronics, biotechnologies, photonics, adhesives, or optical coatings. High filler contents are usually required to fully optimize the nanocomposites properties. However, numerous studies demonstrated that traditional composite viscosity increases with increasing the filler concentration reducing therefore significantly the material processability. In this work, we synthesized inorganic/organic core-shell nanocomposites with different shell thicknesses. By reducing the shell thickness while maintaining a constant core size, the nanoparticle molecular mass decreases but the nanocomposite filler fraction is correlatively increased. We performed viscosity measurements, which clearly highlightedmore » that intrinsic viscosity of hybrid nanoparticles decreases as the molecular mass decreases, and thus, as the filler fraction increases, as opposed to Einstein predictions about the viscosity of traditional inorganic/polymer two-phase mixtures. This exceptional behavior, modeled by Mark-Houwink-Sakurada equation, proves to be a significant breakthrough for the development of industrializable nanocomposites with high filler contents.« less

A review of chemical-approach and ultramorphological studies on the development of fluoride-releasing dental adhesives comprising new pre-reacted glass ionomer (PRG) fillers.

PubMed

Ikemura, Kunio; Tay, Franklin R; Endo, Takeshi; Pashley, David H

2008-05-01

This paper reviews our recent studies on fluoride-releasing adhesives and the related studies in this field based on information from original research papers, reviews, and patent literatures. A revolutionary PRG (pre-reacted glass ionomer) filler technology--where fillers were prepared by the acid-base reaction of a fluoroaluminosilicate glass with polyalkenoic acid in water, was newly developed, and a new category as "Giomer" was introduced into the market. On fluoride release capability, SIMS examination revealed in vitro fluoride ion uptake by dentin substrate from the PRG fillers in dental adhesive. On bonding durability, it was found that the improved durability of resin-dentin bonds might be achieved not only via the strengthened dentin due to fluoride ion uptake from the PRG-Ca fillers, but also due to retention of relatively insoluble 4-AETCa formed around remnant apatite crystallites within the hybrid layer in 4-AET-containing self-etching adhesives. On ultramorphological study of the resin-dentin interface, TEM images of the PRG-Ca fillers revealed that the dehydrated hydrogel was barely distinguishable from normal glass fillers, if not for the concurrent presence of remnant, incompletely reacted glass cores. In conclusion, it was expected that uptake of fluoride ions with cariostatic effect from PRG-Ca fillers would endow dentin substrates with the benefit of secondary caries prevention, together with an effective and durable adhesion to dentin.

14 CFR 27.973 - Fuel tank filler connection.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Fuel tank filler connection. 27.973 Section 27.973 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Fuel System § 27.973 Fuel tank filler connection...

14 CFR 27.973 - Fuel tank filler connection.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Fuel tank filler connection. 27.973 Section 27.973 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Fuel System § 27.973 Fuel tank filler connection...

14 CFR 27.973 - Fuel tank filler connection.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel tank filler connection. 27.973 Section 27.973 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Fuel System § 27.973 Fuel tank filler connection...

14 CFR 27.973 - Fuel tank filler connection.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Fuel tank filler connection. 27.973 Section 27.973 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Fuel System § 27.973 Fuel tank filler connection...

14 CFR 27.973 - Fuel tank filler connection.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Fuel tank filler connection. 27.973 Section 27.973 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Fuel System § 27.973 Fuel tank filler connection...

Improved natural rubber composites reinforced with a complex filler network of biobased nanoparticles and ionomer

USDA-ARS?s Scientific Manuscript database

Biobased rubber composites are renewable and sustainable. Significant improvement in modulus of rubber composite reinforced with hydrophilic filler was achieved with the inclusion of ionomers. Soy particles aided with ionomer, carboxylated styrene-butadiene (CSB), formed a strong complex filler netw...

7 CFR 29.6129 - Farm Filler (Y Group).

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Farm Filler (Y Group). 29.6129 Section 29.6129 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards... REGULATIONS TOBACCO INSPECTION Standards Grades § 29.6129 Farm Filler (Y Group). This group consists of...

Behaviour of Epoxy Silica Nanocomposites Under Static and Creep Loading

NASA Astrophysics Data System (ADS)

Constantinescu, Dan Mihai; Picu, Radu Catalin; Sandu, Marin; Apostol, Dragos Alexandru; Sandu, Adriana; Baciu, Florin

2017-12-01

Specific manufacturing technologies were applied for the fabrication of epoxy-based nanocomposites with silica nanoparticles. For dispersing the fillers in the epoxy resin special equipment such as a shear mixer and a high energy sonicator with temperature control were used. Both functionalized and unfunctionalized silica nanoparticles were added in three epoxy resins. The considered filling fraction was in most cases 0.1, 0.3 and 0.5 wt%.. The obtained nanocomposites were subjected to monotonic uniaxial and creep loading at room temperature. The static mechanical properties were not significantly improved regardless the filler percentage and type of epoxy resin. Under creep loading, by increasing the stress level, the nanocomposite with 0.1 wt% silica creeps less than all other materials. Also the creep rate is reduced by adding silica nanofillers.

Linear ordered collagen scaffolds loaded with collagen-binding basic fibroblast growth factor facilitate recovery of sciatic nerve injury in rats.

PubMed

Ma, Fukai; Xiao, Zhifeng; Chen, Bing; Hou, Xianglin; Dai, Jianwu; Xu, Ruxiang

2014-04-01

Natural biological functional scaffolds, consisting of biological materials filled with promoting elements, provide a promising strategy for the regeneration of peripheral nerve defects. Collagen conduits have been used widely due to their excellent biological properties. Linear ordered collagen scaffold (LOCS) fibers are good lumen fillers that can guide nerve regeneration in an ordered direction. In addition, basic fibroblast growth factor (bFGF) is important in the recovery of nerve injury. However, the traditional method for delivering bFGF to the lesion site has no long-term effect because of its short half-life and rapid diffusion. Therefore, we fused a specific collagen-binding domain (CBD) peptide to the N-terminal of native basic fibroblast growth factor (NAT-bFGF) to retain bFGF on the collagen scaffolds. In this study, a natural biological functional scaffold was constructed using collagen tubes filled with collagen-binding bFGF (CBD-bFGF)-loaded LOCS to promote regeneration in a 5-mm rat sciatic nerve transection model. Functional evaluation, histological investigation, and morphometric analysis indicated that the natural biological functional scaffold retained more bFGF at the injury site, guided axon growth, and promoted nerve regeneration as well as functional restoration.

Ceramic sealants prepared by polymer pyrolysis

NASA Astrophysics Data System (ADS)

Hong, Sung Jin; Kim, Deug Joong; Yoo, Young Sung

2011-02-01

The formation and properties of ceramic seals for SOFC applications prepared by polymer pyrolysis are investigated. A mixture with polymethylsiloxane and fillers are pyrolyzed in a N2 atmosphere. The coefficient of thermal expansion of the ceramic composites was controlled by fillers with a high coefficient of thermal expansion such as AlCo. The morphology of the ceramic composites derived from the mixture with polymethylsiloxane and fillers is composed of fillers embedded in a Si-O-C glass matrix. The thermal expansion behavior and sealing characteristics are measured and discussed

Modification of the epoxy binder for glass and basalt rebar. Mechanical test results

NASA Astrophysics Data System (ADS)

Brusentseva, T. A.

2017-10-01

The paper presents the results of experimental studies on the modification of the epoxy binder LE-828 for the manufacture of glass and basalt rebar. The nano-size silica powder is used as a filler. The filler mass content ranged from 0% to 2%. It is shown that the nano-disperse filler introduced in the binder leads to the increasing breaking stress and tensile strength by 33% and 34%, respectively; the failure strain increased by 39% at the filler mass content of 0.6%.

Elastomer coated filler and composites thereof comprising at least 60% by weight of a hydrated filler and an elastomer containing an acid substituent

NASA Technical Reports Server (NTRS)

Mueller, W. A.; Ingham, J. D.; Reilly, W. W. (Inventor)

1983-01-01

The impact resistance of flame retardant composites, especially thermoplastic molding: compounds containing over 60% hydrated mineral filler such as Al(OH)3 or Mg(OH)2 as improved by coating the filler with 1 to 20% of an elastomer. The composite will fail by crazing or shearing rather than by brittle fracture. A well bonded elastomeric interphase resulted by utilizing acidic substituted resins such as ethyl-hexyl acrylate-acrylic acid copolymers which bond to and are cross-linked by the basic filler particles. Further improvement in impact resistance was provided by incorporating 1 to 10% of a resin fiber reinforcement such as polyvinyl alcohol fibers that decompose to yield at least 30% water when heated to decomposition temperature.

A novel tool for the prediction of tablet sticking during high speed compaction.

PubMed

Abdel-Hamid, Sameh; Betz, Gabriele

2012-01-01

During tableting, capping is a problem of cohesion while sticking is a problem of adhesion. Sticking is a multi-composite problem; causes are either material or machine related. Nowadays, detecting such a problem is a pre-requisite in the early stages of development. The aim of our study was to investigate sticking by radial die-wall pressure monitoring guided by compaction simulation. This was done by using the highly sticking drug; Mefenamic acid (MA) at different drug loadings with different fillers compacted at different pressures and speeds. By increasing MA loading, we found that viscoelastic fillers showed high residual radial pressure after compaction while plastic/brittle fillers showed high radial pressure during compaction, p < 0.05. Visually, plastic/brittle fillers showed greater tendencies for adhesion to punches than viscoelastic fillers while the later showed higher tendencies for adhesion to the die-wall. This was confirmed by higher values of axial stress transmission for plastic/brittle than viscoelastic fillers (higher punch surface/powder interaction), and higher residual die-wall and ejection forces for viscoelastic than plastic/brittle fillers, p < 0.05. Take-off force was not a useful tool to estimate sticking due to cohesive failure of the compacts. Radial die-wall pressure monitoring is suggested as a robust tool to predict sticking.

Thermal properties of oil palm nano filler/kenaf reinforced epoxy hybrid nanocomposites

NASA Astrophysics Data System (ADS)

Saba, N.; Paridah, M. T.; Abdan, K.; Ibrahim, N. A.

2016-11-01

The aim of this research study was to fabricate nano oil palm empty fruit bunch (OPEFB)/kenaf/epoxy hybrid nanocomposites and to make comparative study on the thermal properties of nano OPEFB/kenaf/epoxy hybrid nanocomposites with the montmorillonite (MMT)/kenaf/epoxy hybrid nanocomposites and organically modified MMT (OMMT)/kenaf/epoxy hybrid nanocomposites. Epoxy based kenaf hybrid nanocomposites was prepared by dispersing the nano filler (nano OPEFB filler, MMT, OMMT) at 3% loading through high speed mechanical stirrer followed by hand lay-up technique. Thermal properties of hybrid nanocomposites were analyzed through thermogravimetry analyzer (TGA), and differential scanning calorimetry (DSC). Obtained results specified that addition of nano OPEFB filler improves the thermal stability and char yield of kenaf/epoxy composites. Furthermore, the increase in decomposition temperature by the nano OPEFB filler was quite comparable to the MMT/kenaf/epoxy but relatively less than OMMT/kenaf/epoxy hybrid nanocomposites. We concluded from overall consequences that the nano OPEFB filler can be used as the promising and innovative alternative of existing expensive nano filler, with relatively lesser impact on the environment having marked pronounced impact on the construction, automotive, aerospace, electronics and semiconducting sectors as future industries based on bio-wastes with satisfactory light weight and thermal stability on other side.

Field experiments on eyewitness identification: towards a better understanding of pitfalls and prospects.

PubMed

Wells, Gary L

2008-02-01

The Illinois pilot program on lineup procedures has helped sharpen the focus on the types of controls that are needed in eyewitness field experiments and the limits that exist for interpreting outcome measures (rates of suspect and filler identifications). A widely-known limitation of field experiments is that, unlike simulated crime experiments, the guilt or innocence of the suspects is not easily known independently of the behavior of the eyewitnesses. Less well appreciated is that the rate of identification of lineup fillers, although clearly errors, can be a misleading measure if the filler identification rate is used to assess which of two or more lineup procedures is the better procedure. Several examples are used to illustrate that there are clearly improper procedures that would yield fewer identifications of fillers than would their proper counterparts. For example, biased lineup structure (e.g., using poorly matched fillers) as well as suggestive lineup procedures (that can result from non-blind administration of lineups) would reduce filler identification errors compared to unbiased and non-suggestive procedures. Hence, under many circumstances filler identification rates can be misleading indicators of preferred methods. Comparisons of lineup procedures in future field experiments will not be easily accepted in the absence of double-blind administration methods in all conditions plus true random assignment to conditions.

Experimental Evaluation of Cement Replacement Fillers on the Performance of Slurry Seal

NASA Astrophysics Data System (ADS)

Fakhri, Mansour; Alrezaei, Hossein Ali; Naji Almasi, Soroush

2016-10-01

Reducing the level of roads service is a process that starts from the first day of the operation of road and the slope of deterioration curve of road sustainability becomes faster with the passage of time. After building the road, adopting an economic approach in order to maintain the road is very important. Slurry seal as one type of protective asphalts that works by sealing inactive cracks of the road and increasing skid resistance is the most effective types of restoration with environmentally friendly behaviour. Fillers are responsible for adjusting set time in slurry seal. Cement is the most common filler used in slurry seal. Cements having suitable properties as a filler, has a very energy demanding manufacturing process and a notable amount of energy is used for manufacturing cement in the country annually. On the other hand, manufacturing process and application of cement have increased levels of pollutant gases, followed by significant environmental pollution. So in this study other options as a filler such as hydrated lime, stone powder and the slag from iron melting furnace were compared with two common types of cement (Portland and type-v cement) in the mixtures of slurry seal by wet abrasion and cohesion tests. Results indicated that, in both tests, lime and slag fillers had behaviours close to the cement filler.

Effect of Phthalic Anhydride Modified Soy Protein on Viscoelastic Properties of Polymer Composites

USDA-ARS?s Scientific Manuscript database

Phthalic anhydride (PA) modified soy protein isolates (SPI), both hydrolyzed and un-hydrolyzed, are investigated as reinforcement fillers in styrene-butadiene (SB) composites. The modification of SPI by PA increases the number of carboxylic acid functional groups on the protein surface and therefor...

Reaction of protein and carbohydrates with EDC for purpose of making products with unique functional properties

USDA-ARS?s Scientific Manuscript database

Prior research from this laboratory has demonstrated the feasibility of using chemical and enzymatic treatments on protein and carbohydrate waste products for the purpose of making fillers to enhance the properties of leather. These treatments (microbial transglutaminase, genipin, and polyphenols i...

AA6082 to DX56-Steel Laser Brazing: Process Parameter-Intermetallic Formation Correlation

NASA Astrophysics Data System (ADS)

Narsimhachary, D.; Pal, S.; Shariff, S. M.; Padmanabham, G.; Basu, A.

2017-09-01

In the present study, laser-brazed AA6082 to DX56-galvanized steel joints were investigated to understand the influence of process parameters on joint strength in terms of intermetallic layer formation. 1.5-mm-thick sheet of aluminum alloy (AA6082-T6) and galvanized steel (DX56) sheet of 0.7 mm thickness were laser-brazed with 1.5-mm-diameter Al-12% Si solid filler wire. During laser brazing, laser power (4.6 kW) and wire feed rate (3.4 m/min) were kept constant with a varying laser scan speed of 3.5, 3, 2.5, 2, 1.5, and 1 m/min. Microstructure of brazed joint reveals epitaxial growth at the aluminum side and intermetallic layer formation at steel interface. Intermetallic layer formation was confirmed by EDS analysis and XRD study. Hardness profile showed hardness drop in filler region, and failure during tensile testing was initiated through the filler region near the steel interface. As per both experimental study and numerical analysis, it was observed that intermetallic layer thickness decreases with increasing brazing speed. Zn vaporization from galvanized steel interface also affected the joint strength. It was found that high laser scan speed or faster cooling rate can be chosen for suppressing intermetallic layer formation or at least decreasing the layer thickness which results in improved mechanical properties.

Microstructure and Ductility-Dip Cracking Susceptibility of Circumferential Multipass Dissimilar Weld Between 20MND5 and Z2CND18-12NS with Ni-Base Filler Metal 52

NASA Astrophysics Data System (ADS)

Qin, Renyao; Duan, Zhaoling; He, Guo

2013-10-01

The large circumferential multipass dissimilar weld between 20MND5 steel and Z2CND18-12NS stainless steel welded with FM52 filler material was investigated in terms of the diluted composition, the grain boundary precipitation, and the ductility-dip cracking (DDC) susceptibility of the weld. The diluted composition of the weld is composed of 37 to 47 pct Ni, 21 to 24 pct Cr, and 28 to 40 pct Fe, which are inhomogeneous along the depth and over the width of the deep weld. The carbon content has a distribution in the region of the surface weld from a high level (~0.20 pct) in the zone near 20MND5 steel to a normal level (~0.03 pct) in the zone near Z2CND18-12NS stainless steel. The carbon distribution is corresponding to the grain boundary carbides. The minimum threshold strains for DDC occur in the temperature range of 1223 K to 1323 K (950 °C to 1050 °C), which are 0.5, 0.35, and 0.4 pct for the root weld, middle region, and the surface weld, respectively. The dissimilar weld has the largest susceptibility to the DDC compared to the filler metal 52 and the Inconel 690.

Complications of Minimally Invasive Cosmetic Procedures: Prevention and Management

PubMed Central

Levy, Lauren L; Emer, Jason J

2012-01-01

Over the past decade, facial rejuvenation procedures to circumvent traditional surgery have become increasingly popular. Office-based, minimally invasive procedures can promote a youthful appearance with minimal downtime and low risk of complications. Injectable botulinum toxin (BoNT), soft-tissue fillers, and chemical peels are among the most popular non-invasive rejuvenation procedures, and each has unique applications for improving facial aesthetics. Despite the simplicity and reliability of office-based procedures, complications can occur even with an astute and experienced injector. The goal of any procedure is to perform it properly and safely; thus, early recognition of complications when they do occur is paramount in dictating prevention of long-term sequelae. The most common complications from BoNT and soft-tissue filler injection are bruising, erythema and pain. With chemical peels, it is not uncommon to have erythema, irritation and burning. Fortunately, these side effects are normally transient and have simple remedies. More serious complications include muscle paralysis from BoNT, granuloma formation from soft-tissue filler placement and scarring from chemical peels. Thankfully, these complications are rare and can be avoided with excellent procedure technique, knowledge of facial anatomy, proper patient selection, and appropriate pre- and post-skin care. This article reviews complications of office-based, minimally invasive procedures, with emphasis on prevention and management. Practitioners providing these treatments should be well versed in this subject matter in order to deliver the highest quality care. PMID:23060707

Influence of different fillers on the properties of an experimental vinyl polysiloxane.

PubMed

Meincke, Débora Könzgen; Ogliari, Aline de Oliveira; Ogliari, Fabrício Aulo

2016-01-01

The aim of the study was to evaluate the effect of the incorporation of different fillers on an experimental vinyl polysiloxane (VPS) at two different concentrations, 20% and 40%. Different fillers were added to an experimental VPS. The study was developed in two stages: (i) incorporation of fillers in different concentrations: (a) 20 wt% fillers, and (b) 40 wt%. The fillers were added to experimental VPS and mixed with a speed mixer; (ii) characterization of experimental VPS; after the base paste and catalyst paste were mixed, the experimental VPS was used to make specimens specifically for each test, which were stored at 23°C for 24 hours. The tests were designed according to the specific standardization for the analysis of tensile strength, detail reproduction, Shore A hardness, and elastic recovery. For analysis of filler size pattern, scanning electron microscopy at 1500× magnification was used. The aerosil OX-50 40% (AE), and pure aluminum hydroxide 40% (PAH) groups presented the highest tensile strength and Shore A hardness values. However, those were the only groups that did not present continuous detail reproduction of an intersection of 20 μm line. The elastic recovery was not statistically significant. The undesirable characteristics of VPS (lowest Shore A hardness and tensile strength) were observed when it was added to the composition of acrylic polymer (AP) and fiberglass (FG) in both concentrations, 20% and 40%. In groups AE and PAH, agglomerates of nanofillers were shown in SEM micrography, while the other groups presented different shapes and fillers sizes.

Evaluation of elastic properties and study on water absorption behavior of alumina filled jute-epoxy composites

NASA Astrophysics Data System (ADS)

Santosh, D. N.; Ravikumar, B. N.; Mahesh, B.; Vijayalaxmi, S. P.; Srinivas, Y. V.

2018-04-01

In this paper, the effect of filler content is studied on elastic properties and water absorption behavior for jute epoxy composite. For reinforcement the plain woven jute fabric is used. The bonding system consists of resin-epoxy and Hardener in the ratio 10:1 by weight. Alumina (average grain size of 30 µm) is used as filler. The effect of filler content on elastic properties and water absorption behavior studied by varying the filler content from 5%, 10%, 15% with respect to weight of epoxy. The open mould method used to fabricate the alumina filled jute-epoxy composite laminates. Tests were conducted according to ASTM standards. The evaluation assesment of elastic properties of alumina filled jute-epoxy composite materials have been analyzed by theoretically and experimentally. The speculated values are analyzed with those obtained from experimental to validate the calculated theoretically with rule of mixture procedure. Young's modulus and shear modulus were found to increase with the increase in the filler content upto 10 wt%, beyond which the modulii showed decreasing trend. Poisson's ratio was found to be continuously decreasing with the increase in the alumina filler content of jute-eposy composite. It was clearly observed that unfilled specimen has the highest saturated moisture content and 15% filled specimen has lowest value. As alumina filler content increases resistance to moisture absorption also increases. The water diffusion coefficient of composite was calculated using the diffusion coefficient equation. As filler content increases diffusion co-efficient decreases for alumina filled jute-epoxy composite.

Mesoporous silica fillers and resin composition effect on dental composites cytocompatibility.

PubMed

Attik, Nina; Hallay, Franck; Bois, Laurence; Brioude, Arnaud; Grosgogeat, Brigitte; Colon, Pierre

2017-02-01

Many new dental composites containing mesoporous silica fillers have been developed to improve rheological properties and enhance the resin-filler interface. To investigate the correlation between the cytocompatibility of several dental composites and their composition; two aspects have been considered: presence of bisphenol A (BPA)-glycidyl methacrylate (Bis-GMA) or triethyleneglycol-dimethacrylate (TEGDMA) among the resin monomers and presence of porous particles among the filler blends. Five commercial composites with different resin matrices and mineral fillers were compared to four experimental composites designed without any BPA-based monomers or TEGDMA. Porous fillers, with or without silanation, were added in some of the experimental composites. Two reference resin matrices were also selected. Cytocompatibility with cultured primary human gingival fibroblasts was assessed by confocal laser scanning microscopy with time-lapse imaging. Fourier transform infrared spectroscopy was used to control monomer conversion rate. Conversion rates of the experimental composites ranged from 57% to 71%, a comparable ratio for dental composites. Experimental samples were better tolerated than tested commercial samples not containing TEGDMA and significantly better than those containing TEGDMA. Experimental composites with porous fillers exhibited good cytocompatibility, especially when surfaces were silanated. Cytotoxicity was associated with resin amount and especially resin nature. Composites containing porous fillers might behave as if the resin trapped into pores has no effect on toxicity. The cytotoxicity of composites with and without BPA derivatives was mainly attributed to the release of residual TEGDMA rather than the BPA derivatives. Copyright © 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Specific surface area of overlapping spheres in the presence of obstructions

NASA Astrophysics Data System (ADS)

Jenkins, D. R.

2013-02-01

This study considers the random placement of uniform sized spheres, which may overlap, in the presence of another set of randomly placed (hard) spheres, which do not overlap. The overlapping spheres do not intersect the hard spheres. It is shown that the specific surface area of the collection of overlapping spheres is affected by the hard spheres, such that there is a minimum in the specific surface area as a function of the relative size of the two sets of spheres. The occurrence of the minimum is explained in terms of the break-up of pore connectivity. The configuration can be considered to be a simple model of the structure of a porous composite material. In particular, the overlapping particles represent voids while the hard particles represent fillers. Example materials are pervious concrete, metallurgical coke, ice cream, and polymer composites. We also show how the material properties of such composites are affected by the void structure.

Specific surface area of overlapping spheres in the presence of obstructions.

PubMed

Jenkins, D R

2013-02-21

This study considers the random placement of uniform sized spheres, which may overlap, in the presence of another set of randomly placed (hard) spheres, which do not overlap. The overlapping spheres do not intersect the hard spheres. It is shown that the specific surface area of the collection of overlapping spheres is affected by the hard spheres, such that there is a minimum in the specific surface area as a function of the relative size of the two sets of spheres. The occurrence of the minimum is explained in terms of the break-up of pore connectivity. The configuration can be considered to be a simple model of the structure of a porous composite material. In particular, the overlapping particles represent voids while the hard particles represent fillers. Example materials are pervious concrete, metallurgical coke, ice cream, and polymer composites. We also show how the material properties of such composites are affected by the void structure.

Discontinuous Development in the Acquisition of Filler-Gap Dependencies: Evidence from 15- and 20-Month-Olds

ERIC Educational Resources Information Center

Gagliardi, Annie; Mease, Tara M.; Lidz, Jeffrey

2016-01-01

This article investigates infant comprehension of filler-gap dependencies. Three experiments probe 15- and 20-month-olds' comprehension of two filler-gap dependencies: "wh"-questions and relative clauses. Experiment 1 shows that both age groups appear to comprehend "wh"-questions. Experiment 2 shows that only the younger…

Fillers as Signals: Evidence from a Question-Answering Paradigm

ERIC Educational Resources Information Center

Walker, Esther J.; Risko, Evan F.; Kingstone, Alan

2014-01-01

The present study examined the influence of a human or computer "partner" on the production of fillers ("um" and "uh") during a question and answer task. Experiment 1 investigated whether or not responding to a human partner as opposed to a computer partner results in a higher rate of filler production. Participants…

Comparison of TT-F-1098 Solvent-Thinned Block Fillers with Water-Thinnable Block Fillers.

DTIC Science & Technology

1985-03-01

saved money , because the latex is less roller were visible. The appearance of the surface expensive than the epoxy it replaced. In both cases...a previous coating. A kit manu- The appearance of all the fillers was satisfactory. factured b, Paul N. Gardner Company, Inc., Lauder - Voids were

Fillers as Signs of Distributional Learning

ERIC Educational Resources Information Center

Taelman, Helena; Durieux, Gert; Gillis, Steven

2009-01-01

A longitudinal analysis is presented of the fillers of a Dutch-speaking child between 1;10 and 2;7. Our analysis corroborates familiar regularities reported in the literature: most fillers resemble articles in shape and distribution, and are affected by rhythmic and positional constraints. A novel finding is the impact of the lexical environment:…

Filler Items and Social Desirability in Rotter's Locus of Control Scale

ERIC Educational Resources Information Center

Kestenbaum, Joel M.; Hammersla, Joy

1976-01-01

Three experiments were conducted with college psychology students to determine whether the use of filler items in Rotter's I-E scale fulfills its stated objective of obscuring the purpose of the scale. Fillers didn't effect I-E scores, impede subjects from faking good, or obscure knowledge of the scale. (Author/DEP)

Effect of strain rate on mechanical properties of melt-processed soy flour composite filler and styrene-butadiene blends

USDA-ARS?s Scientific Manuscript database

Polymer composites were prepared by melt-mixing polymer and soy flour composite fillers in an internal mixer. Soy flour composite fillers were prepared by blending aqueous dispersion of soy flour with styrene-butadiene rubber latex, dried, and cryogenically ground into powders. Upon crosslinking, th...

Evaluating corn starch and corn stover biochar as renewable filler in carboxylated styrene-butadiene rubber composites

USDA-ARS?s Scientific Manuscript database

Corn starch, corn flour, and corn stover biochar were evaluated as potential renewable substitutes for carbon black as filler in rubber composites using carboxylated styrene-butadiene as the rubber matrix. Previous work has shown that starch-based fillers have very good reinforcement properties at t...

Intumescent-ablator coatings using endothermic fillers

NASA Technical Reports Server (NTRS)

Sawko, P. M.; Riccitiello, S. R. (Inventor)

1978-01-01

An intumescent-ablator coating composition which contains the ammonium salt of 1,4-nitroaniline-2-sulfonic acid or 4,4 dinitrosul fanilide, a polymeric binder system and about 5 to 30% weight of an endothermic filler is reported. The filler has a decomposition temperature about or within the exothermic region of the intumescent agent.

Filler Wire Development for 2195 Aluminum-Lithium

NASA Technical Reports Server (NTRS)

Bjorkman, Gerry; Cho, Alex; Russell, Carolyn; Zimmerman, Frank

1998-01-01

The presentation outline summarizes activities supporting the development of filler wire for 215 aluminum-lithium. The specific objective of the research was to identify an Al-Cu based filler wire chemistry which reduces weld susceptibility in 2195 Aluminum-Lithium welds and repairs welds along with providing adequate mechanical properties. This report is in viewgraph form.

Effect of filler metals on the mechanical properties of Inconel 625 and AISI 904L dissimilar weldments using gas tungsten arc welding

NASA Astrophysics Data System (ADS)

Senthur Prabu, S.; Devendranath Ramkumar, K.; Arivazhagan, N.

2017-11-01

In the present research work, dissimilar welding between Inconel 625 super alloy and AISI 904L super austenitic stainless steel using manual multi-pass continuous current gas tungsten arc (CCGTA) welding process employed with ERNiCrMo-4 and ERNiCrCoMo-1 fillers were performed to determine the mechanical properties and weldability. Tensile test results corroborated that the fracture had occurred at the parent metal of AISI 904L irrespective of filler used for all the trials. The presence of the macro and micro void coalescence in the fibrous matrix characterised for ductile mode of fracture. The hardness values at the weld interface of Inconel 625 side were observed to be higher for ERNiCrMo-4 filler due to the presence of strengthening elements such as W, Mo, Ni and Cr. The impact test accentuated that the weldments using ERNiCrMo-4 filler offered better impact toughness (41J) at room temperature. Bend test results showed that the weldments using these fillers exhibited good ductility without cracks.

Effect of Silver-Emitting Filler on Antimicrobial and Mechanical Properties of Soft Denture Lining Material

PubMed Central

Jabłońska-Stencel, Ewa; Pakieła, Wojciech; Mertas, Anna; Bobela, Elżbieta; Kasperski, Jacek; Chladek, Grzegorz

2018-01-01

Colonization of silicone-based soft lining materials by pathogenic yeast-type fungi is a common problem associated with the use of dentures. In this study, silver sodium hydrogen zirconium phosphate (SSHZP) was introduced into polydimethylsiloxane-based material as an antimicrobial filler at concentrations of 0.25, 0.5, 1, 2, 4, 6, 8, 10, 12, and 14% (w/w). The in vitro antimicrobial efficacy was investigated. Candida albicans was used as a characteristic representative of pathogenic oral microflora. Staphylococcus aureus and Escherichia coli were used as the typical Gram-positive and Gram-negative bacterial strains, respectively. The effect of filler addition on the Shore A hardness, tensile strength, tensile bond strength, sorption, and solubility was investigated. An increase in the filler concentration resulted in an increase in hardness, sorption, and solubility, and for the highest concentration, a decrease in bond strength. The favorable combination of antimicrobial efficacy with other properties was achieved at filler concentrations ranging from 2% to 10%. These composites exhibited mechanical properties similar to the material without the antimicrobial filler and enhanced in vitro antimicrobial efficiency. PMID:29470441

Highly conductive, multi-layer composite precursor composition to fuel cell flow field plate or bipolar plate

DOEpatents

Jang, Bor Z [Centerville, OH; Zhamu, Aruna [Centerville, OH; Guo, Jiusheng [Centerville, OH

2011-02-15

This invention provides a moldable, multiple-layer composite composition, which is a precursor to an electrically conductive composite flow field plate or bipolar plate. In one preferred embodiment, the composition comprises a plurality of conductive sheets and a plurality of mixture layers of a curable resin and conductive fillers, wherein (A) each conductive sheet is attached to at least one resin-filler mixture layer; (B) at least one of the conductive sheets comprises flexible graphite; and (C) at least one resin-filler mixture layer comprises a thermosetting resin and conductive fillers with the fillers being present in a sufficient quantity to render the resulting flow field plate or bipolar plate electrically conductive with a conductivity no less than 100 S/cm and thickness-direction areal conductivity no less than 200 S/cm.sup.2.

Dielectric properties of inorganic fillers filled epoxy thin film

NASA Astrophysics Data System (ADS)

Norshamira, A.; Mariatti, M.

2015-07-01

The demand on the small size and high performance electronics has driven changes in the electronic packaging requirements from discrete capacitor to embedded capacitor. Embedded capacitor can improve electrical performance compared with discrete capacitor. This study aimed to achieve high dielectric of epoxy thin film composite that were targeted for application as embedded capacitor. In this study, inorganic fillers such as Calcium Copper Titanate (CCTO), Iron(III) Oxide (Fe2O3) and Titanium Dioxide (TiO2) were loaded in epoxy system at 5 and 20vol%. Morphology and dielectric properties were investigated to identify the effect of fillers loading and types of fillers on the properties of epoxy thin film composite. Based on the study, CCTO with 20vol% loading was found to have good dielectric properties compared to other type of fillers.

Plasma arc torch with coaxial wire feed

DOEpatents

Hooper, Frederick M

2002-01-01

A plasma arc welding apparatus having a coaxial wire feed. The apparatus includes a plasma arc welding torch, a wire guide disposed coaxially inside of the plasma arc welding torch, and a hollow non-consumable electrode. The coaxial wire guide feeds non-electrified filler wire through the tip of the hollow non-consumable electrode during plasma arc welding. Non-electrified filler wires as small as 0.010 inches can be used. This invention allows precision control of the positioning and feeding of the filler wire during plasma arc welding. Since the non-electrified filler wire is fed coaxially through the center of the plasma arc torch's electrode and nozzle, the wire is automatically aimed at the optimum point in the weld zone. Therefore, there is no need for additional equipment to position and feed the filler wire from the side before or during welding.

Filler characteristics of modern dental resin composites and their influence on physico-mechanical properties.

PubMed

Randolph, Luc D; Palin, William M; Leloup, Gaëtane; Leprince, Julian G

2016-12-01

The mechanical properties of dental resin-based composites (RBCs) are highly dependent on filler characteristics (size, content, geometry, composition). Most current commercial materials are marketed as "nanohybrids" (i.e. filler size <1μm). In the present study, filler characteristics of a selection of RBCs were described, aiming at identifying correlations with physico-mechanical properties and testing the relevance of the current classification. Micron/sub-micron particles (> or <500nm) were isolated from 17 commercial RBCs and analyzed by laser diffractrometry and/or electron microscopy. Filler and silane content were evaluated by thermogravimetric analysis and a sedimentation technique. The flexural modulus (E flex ) and strength (σ flex ) and micro-hardness were determined by three-point bending or with a Vickers indenter, respectively. Sorption was also determined. All experiments were carried out after one week of incubation in water or 75/25 ethanol/water. Average size for micron-sized fillers was almost always higher than 1μm. Ranges for mechanical properties were: 3.775wt%) were associated with the highest mechanical properties (E flex and σ flex >12GPa and 130MPa, respectively) and lowest solvent sorption (∼0.3%). Mechanical properties and filler characteristics significantly vary among modern RBCs and the current classification does not accurately illustrate either. Further, the chemical stability of RBCs differed, highlighting differences in resin and silane composition. Since E flex and sorption were well correlated to the filler content, a simple and unambiguous classification based on such characteristic is suggested, with three levels (ultra-low fill, low-fill and compact resin composites). Copyright © 2016 The Academy of Dental Materials. All rights reserved.

Graphene-silicone elastomer nanocomposite

NASA Astrophysics Data System (ADS)

Pan, Shuyang

The incorporation of fillers to improve the Young's modulus, tensile strength, and elongation at failure of polymeric matrices is ubiquitous. While Young's modulus and tensile strength of the matrix increase with the filler concentration, a threshold filler concentration must be achieved for the elongation at failure to increase. Furthermore, a decrease in elongation at failure has also been observed beyond a critical filler concentration. While the increases in modulus and tensile strength have been attributed to the transfer of mechanical load to the stronger filler, the onset and reversal in elongation at failure are not understood. In this thesis, we use a functionalized graphene sheet (FGS) -- silicone elastomer (SE) nanocomposite as a model system to demonstrate the mechanisms responsible for this observed filler concentration-dependant elongation at failure as well its subsequent reversal. We will also demonstrate the mechanisms that create the continual increase in tensile strength as filler concentration increases. As the lateral size of FGS strongly influences the tensile strength of the resulting composite, in the first part of this thesis, we show that the oxidation path and the mechanical energy input influence the size of graphene oxide sheets derived from graphite oxide. The cross-planar oxidation of graphite from the (0002) plane results in periodic cracking of the uppermost graphene oxide layer, limiting its lateral dimension to less than 30 microm. We use an energy balance between the elastic strain energy associated with the undulation of graphene oxide sheets at the hydroxyl and epoxy sites, the crack formation energy, and the interaction energy between graphene layers to determine the cell size of the cracks. Under both edge-to-center and cross-planar oxidations, the size of graphene oxide sheets is determined by the aspect ratio of graphite and the mechanical energy input in processing the sheets. In the second part of this thesis, we use atomic force microscopy-based single molecule force spectroscopy and infrared spectroscopy to show that the FGS-SE interface is dominated by the hydrogen bonds between the hydroxyl and epoxy groups on FGS and polydimethylsiloxane (PDMS, uncrosslinked form of SE) monomers. These hydrogen bonds allow the mechanical load to be transferred from the weaker SE to the stronger FGS, leading to an improvement in the tensile strength of SE. The strength of a single PDMS-FGS hydrogen bond is measured to be 30-120 pN and it is on the same order of magnitude as the strengths of other types of hydrogen bonds previously reported. In the final part of the thesis, utilizing experimental analysis and a two dimensional viscoelastic lattice model constructed by our collaborators, we show that while load transfer to FGS is the main cause of the enhancements in modulus and strength, the enhancement in elongation at failure is due to FGS-induced distributed tearing. First critical concentration, which defines the mechanical percolation, corresponds to the isolation of tensile zones generated by the fillers, as well as the initiation of tear arresting and deflection, thus enhancing distributed tearing and deformation. At the second critical concentration, cumulative dilation caused by distributed tearing reaches a maximum, leading to the reversal in elongation in failure.

Heat resistant substrates and battery separators made therefrom

NASA Technical Reports Server (NTRS)

Langer, Alois (Inventor); Scala, Luciano C. (Inventor); Ruffing, Charles R. (Inventor)

1976-01-01

A flexible substrate having a caustic resistant support and at least one membrane comprising a solid polymeric matrix containing a network of interconnected pores and interdispersed inorganic filler particles with a ratio of filler: polymer in the polymeric matrix of between about 1:1 to 5:1, is made by coating at least one side of the support with a filler:coating formulation mixture of inorganic filler particles and a caustic resistant, water insoluble polymer dissolved in an organic solvent, and removing the solvent from the mixture to provide a porous network within the polymeric matrix.

Filler migration and extensive lesions after lip augmentation: Adverse effects of polydimethylsiloxane filler.

PubMed

Abtahi-Naeini, Bahareh; Faghihi, Gita; Shahmoradi, Zabihollah; Saffaei, Ali

2018-01-07

Polydimethylsiloxane (PDMS), also called liquid silicone, belongs to a group of polymeric compounds that are commonly referred to as silicones. These filling agents have been used as injectable filler for soft tissue augmentation. There are limited experiences about management of the severe complications related to filler migration associated with PDMS injection. We present a 35-year-old female with severe erythema, edema over her cheeks and neck, and multiple irregularities following cosmetic lip augmentation with PDMS. Further studies are required for management of this complicated case of PDMS injection. © 2018 Wiley Periodicals, Inc.

Aluminum Lithium Alloy 2195 Fusion Welding Improvements with New Filler Wire

NASA Technical Reports Server (NTRS)

Russell, C.

2001-01-01

The objective of this research was to assess the B218 weld filler wire for Super Lightweight External Tank production, which could improve current production welding and repair productivity. We took the following approaches: (1) Perform a repair weld quick look evaluation between 4043/B218 and B218/B218 weld filler wire combinations and evaluation tensile properties for planished and unplanished conditions; and (2) Perform repair weld evaluation on structural simulation panel using 4043-B218 and B218/B218 weld filler wire combinations and evaluation tensile and simulated service fracture properties for planished and unplanished conditions.

Microstructure and Mechanical Properties of Stainless Steel/Brass Joints Brazed by Sn-Electroplated Ag Brazing Filler Metals

NASA Astrophysics Data System (ADS)

Wang, Xingxing; Peng, Jin; Cui, Datian

2018-05-01

To develop a high-Sn-content AgCuZnSn brazing filler metal, the BAg50CuZn was used as the base filler metal and a Sn layer was electroplated upon it. Then, the 304 stainless steel and the H62 brass were induction-brazed with the Sn-plated brazing filler metals. The microstructures of the joints were examined with an optical microscope, a scanning electron microscope and an x-ray diffractometer. The corresponding mechanical properties were obtained with a universal tensile testing machine. The results indicated that the induction brazed joints consisted of the Ag phase, the Cu phase and the CuZn phase. When the content of Sn in the Sn-plated Ag brazing filler metal was 6.0 or 7.2 wt.%, the Cu5Zn8, the Cu41Sn11 and the Ag3Sn phases appeared in the brazed joint. The tensile strength of the joints brazed with the Sn-plated filler metal was higher compared to the joints with the base filler metal. When the content of Sn was 6.0 wt.%, the highest tensile strength of the joint reached to 395 MPa. The joint fractures presented a brittle mode, mixed with a low amount of ductile fracture, when the content of Sn exceeded 6.0 wt.%.

High-Temperature Active Soldering of SiC Particle-Reinforced Al-MMC Using a Novel ZnAlGaMgTi Filler Metal

NASA Astrophysics Data System (ADS)

Chen, Biqiang; Zhang, Guifeng; Zhang, Linjie; Xu, Tingting

2017-10-01

In order to broaden the application of SiC particle-reinforced aluminum matrix composite in electronics packaging, newly developed ZnAlGaMgTi filler with a low melting point of 418-441 °C was utilized as filler metal for active soldering of aluminum matrix composites (70 vol.%, SiCp/Al-MMCs) for the first time. The effect of loading pressure on joint properties of ZnAlGaMgTi active filler was investigated. The experimental results indicated that novel filler could successfully solder Al-MMCs, and the presence of Mg in the filler enhanced the penetration of Zn, while the forming of Zn-rich barrier layer influenced the active element MPD (melting point depressant) diffusion into parent composite, and the bulk-like (Mg-Si)-rich phase and Ti-containing phase were readily observed at the interface and bond seam. With the increase in loading pressure, the runout phenomenon appeared more significant, and the filler foil thickness and the Zn penetration depth varied pronouncedly. Sound joints with maximum shear strength of 29.6 MPa were produced at 480 °C at 1 MPa, and the crack occurred adjacent to the boundary of SiC particle and then propagated along the interface. A novel model describing the significant mutual diffusion of Al and Zn atoms between the parent material and solder was proposed.

Tensile properties of chrome tanned leather waste short fibre filled unsaturated polyester composite

NASA Astrophysics Data System (ADS)

Talib, Satariah; Romli, Ahmad Zafir; Saad, Siti Zaleha

2017-12-01

Waste leather from industries was commonly disposed via land filling or incineration where the oxidation of Cr III to Cr VI by oxidants (such as peroxides and hypohalide) can easily occur. Cr VI is well known as carcinogenic and mutagenic element where the excessive exposure to this element can be very harmful. As an alternative way, the leather waste from footwear industry was utilised as filler in unsaturated polyester composite (UPC). The leather waste was ground using 0.25 mm mesh size and used without any chemical treatment. The sample was fabricated via castingtechnique and the study was carried out at 1 wt%, 2 wt% and 3 wt% filler loading. The leather waste filled composites showed lower tensile strength and Young's modulus than the unfilled composite. The increasing loading amount of leather waste led to the decreased in tensile strength and Young's modulus. The tensile results was supported by the decreasing pattern of density result which indicates the increasing of void content as the filler loading increased. The results of glass transition temperature are also parallel to the tensile properties where the increasing filler loading had decreased the glass transition temperature. Based on the morphological observation on the fractured tensile sample, much severe filler agglomerations and higher amount of voids was observed at higher filler loading compared to the lower filler loading.

Viscoelastic Properties of Rubber Composites Reinforced by Wheat Gluten and Wheat Starch Co-filler

USDA-ARS?s Scientific Manuscript database

Due to different abilities of wheat gluten (WG) and wheat starch (WS) to increase the modulus of rubber composites, the composite properties can be adjusted by varying the ratio of WG to WS as a co-filler. This study shows that the co-filler composites became more temperature dependent as the WG co...

Viscoelastic Properties of Rubber Composites Reinforced by Wheat Gluten and Starch Co-filler

USDA-ARS?s Scientific Manuscript database

Due to different abilities of wheat gluten (WG) and wheat starch (WS) to increase the modulus of rubber composites, the composite properties can be adjusted by varying the ratio of WG to WS as a co-filler. This study shows that the co-filler composites became more temperature dependent as the WG co...

Effect of Dispersoid on Sulfonium Ionic Liquid Based Gel Polymer Electrolyte for Lithium Secondary Battery.

PubMed

Muthupradeepa, R; Sivakumar, M; Subadevi, R; Suryanarayanan, V; Liu, Wei-Ren

2018-01-01

The present study emphases on the effect of toting of TiO2 filler on the electrochemical enactment of polymer electrolyte containing PVdF-co-HFP(30) + SEt3TFSI(10) + EC/PC(60) + TiO2(x) wt% (Poly (vinylidene fluoride-co-hexafluoropropylene + Triethylsulfoniumbis(trifluoromethylsulfonyl)imide + Ethylene carbonate/Propylene carbonate (1:1 ratio) + Titanium dioxide) for lithium battery applications. Composite electrolytes with different weight percentages of TiO2 were prepared and characterized by different surface analytical, thermal and electrochemical techniques. With gradual increase of the amount of TiO2 upto 6 wt%, broadening of the prominent peak has been noted, suggesting a decrease in the degree of crystallinity upon the addition of TiO2, as revealed by X-ray diffraction (XRD). Raman and FT-IR studies confirm the presence of various functional groups, present in the matrix. The electrolyte with TiO2 (6 wt%) has maximum stability of 460 °C, as confirmed by thermal analysis. Conductivity of the composite polymer electrolytes increases upto 6 wt% of TiO2 (3.42 × 10-3 S/cm at 303 K) and further addition, causes a dip down in conductivity, indicating an improvement in the ionic conductivity and thermal stability with the incorporation of TiO2 filler. Surface morphologic images show the presence of surface and cavity in the polymer matrix, filled with the filler uniformly. Voltammetric studies confirm the electrochemical stability of films upto 4.62 V. Coin cell containing Li anode and LiFePO4 cathode along with polymer electrolyte/6 wt% TiO2 filler, delivers a first discharge capacity of 145 mAh/g with the working voltage of 3.4 V.

Microstructural Evolution of the Interface Between Pure Titanium and Low Melting Point Zr-Ti-Ni(Cu) Filler Metals

NASA Astrophysics Data System (ADS)

Lee, Dongmyoung; Sun, Juhyun; Kang, Donghan; Shin, Seungyoung; Hong, Juhwa

2014-12-01

Low melting point Zr-based filler metals with melting point depressants (MPDs) such as Cu and Ni elements are used for titanium brazing. However, the phase transition of the filler metals in the titanium joint needs to be explained, since the main element of Zr in the filler metals differs from that of the parent titanium alloys. In addition, since the MPDs easily form brittle intermetallics, that deteriorate joint properties, the phase evolution they cause needs to be studied. Zr-based filler metals having Cu content from 0 to 12 at. pct and Ni content from 12 to 24 at. pct with a melting temperature range of 1062 K to 1082 K (789 °C to 809 °C) were wetting-tested on a titanium plate to investigate the phase transformation and evolution at the interface between the titanium plate and the filler metals. In the interface, the alloys system with Zr, Zr2Ni, and (Ti,Zr)2Ni phases was easily changed to a Ti-based alloy system with Ti, Ti2Ni, and (Ti,Zr)2Ni phases, by the local melting of parent titanium. The dissolution depths of the parent metal were increased with increasing Ni content in the filler metals because Ni has a faster diffusion rate than Cu. Instead, slow diffusion of Cu into titanium substrate leads to the accumulation of Cu at the molten zone of the interface, which could form undesirable Ti x Cu y intermetallics. This study confirmed that Zr-based filler metals are compatible with the parent titanium metal with the minimum content of MPDs.

Osteoconductive Amine-Functionalized Graphene-Poly(methyl methacrylate) Bone Cement Composite with Controlled Exothermic Polymerization.

PubMed

Sharma, Rakesh; Kapusetti, Govinda; Bhong, Sayali Yashwant; Roy, Partha; Singh, Santosh Kumar; Singh, Shikha; Balavigneswaran, Chelladurai Karthikeyan; Mahato, Kaushal Kumar; Ray, Biswajit; Maiti, Pralay; Misra, Nira

2017-09-20

Bone cement has found extensive usage in joint arthroplasty over the last 50 years; still, the development of bone cement with essential properties such as high fatigue resistance, lower exothermic temperature, and bioactivity has been an unsolved problem. In our present work, we have addressed all of the mentioned shortcomings of bone cement by reinforcing it with graphene (GR), graphene oxide (GO), and surface-modified amino graphene (AG) fillers. These nanocomposites have shown hypsochromic shifts, suggesting strong interactions between the filler material and the polymer matrix. AG-based nanohybrids have shown greater osteointegration and lower cytotoxicity compared to other nanohybrids as well as pristine bone cement. They have also reduced oxidative stress on cells, resulting in calcification within 20 days of the implantation of nanohybrids into the rabbits. They have significantly reduced the exothermic curing temperature to body temperature and increased the setting time to facilitate practitioners, suggesting that reaction temperature and settling time can be dynamically controlled by varying the concentration of the filler. Thermal stability and enhanced mechanical properties have been achieved in nanohybrids vis-à-vis pure bone cement. Thus, this newly developed nanocomposite can create natural bonding with bone tissues for improved bioactivity, longer sustainability, and better strength in the prosthesis.

The Apparent Contact Angle and Wetted Area of Active Alloys on Silicon Carbide as a Function of the Temperature and the Surface Roughness: A Multivariate Approach

NASA Astrophysics Data System (ADS)

Tillmann, Wolfgang; Pfeiffer, Jan; Wojarski, Lukas

2015-08-01

Despite the broad field of applications for active filler alloys for brazing ceramics, as well as intense research work on the wetting and spreading behavior of these alloys on ceramic surfaces within the last decades, the manufactured joints still exhibit significant variations in their properties due to the high sensitivity of the alloys to changing brazing conditions. This increases the need for investigations of the wetting and spreading behavior of filler alloys with regard to the dominating influences combined with their interdependencies, instead of solely focusing on single parameter investigations. In this regard, measurements of the wetting angle and area were conducted at solidified AgCuTi and CuSnTi alloys on SiC substrates. Based on these measurements, a regression model was generated, illustrating the influence of the brazing temperature, the roughness of the faying surfaces, the furnace atmosphere, and their interdependencies on the wetting and spreading behavior of the filler alloys. It was revealed that the behavior of the melts was significantly influenced by the varied brazing parameters, as well as by their interdependencies. This result was also predicted by the developed model and showed a high accuracy.

Colligative thermoelectric transport properties in n-type filled CoSb{sub 3} determined by guest electrons in a host lattice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lim, Young Soo, E-mail: yslim@pknu.ac.kr, E-mail: wsseo@kicet.re.kr, E-mail: pmoka@lgchem.com; Park, Kwan-Ho; Tak, Jang Yeul

2016-03-21

Among many kinds of thermoelectric materials, CoSb{sub 3} has received exceptional attention for automotive waste heat recovery. Its cage structure provides an ideal framework for the realization of phonon-glass electron-crystal strategy, and there have been numerous reports on the enhanced thermoelectric performance through the independent control of the thermal and electrical conductivity by introducing fillers into its cage sites. Herein, we report colligative thermoelectric transport properties in n-type CoSb{sub 3} from the viewpoint of “guest electrons in a host lattice.” Both the Seebeck coefficient and the charge transport properties are fundamentally determined by the concentration of the guest electrons, whichmore » are mostly donated by the fillers, in the conduction band of the host CoSb{sub 3}. Comparing this observation to our previous results, colligative relations for both the Seebeck coefficient and the mobility were deduced as functions of the carrier concentration, and thermoelectric transport constants were defined to predict the power factor in filled CoSb{sub 3}. This discovery not only increases the degree of freedom for choosing a filler but also provides the predictability of power factor in designing and engineering the n-type filled CoSb{sub 3} materials.« less

Reinforcing of a calcium phosphate cement with hydroxyapatite crystals of various morphologies.

PubMed

Neira, Inés S; Kolen'ko, Yury V; Kommareddy, Krishna P; Manjubala, Inderchand; Yoshimura, Masahiro; Guitián, Francisco

2010-11-01

A series of biocomposite materials was successfully prepared by reinforcing advanced calcium phosphate cement with hydroxyapatite fibrous and elongated plate-like particles. Powder X-ray diffraction showed that ball-milled biocomposite precursors (dicalcium and tetracalcium phosphates) entirely transform to a single phase hydroxyapatite end product within 7 h at 37 °C. Electron microscopy showed that the resultant biocomposites are constituted of nanoscaled cement particles intimately associated with the reinforcement crystals. The influence of shape, size, and concentration of the hydroxyapatite filler on the compression strength of reinforced cements is discussed. The best compression strength of 37 ± 3 MPa (enhancement of ∼50% compared to pure cement) was achieved using submicrometer-sized hydroxyapatite crystals with complementary shapes. Nanoindentation revealed that averaged elastic modulus and hardness values of the cements are consistent with those reported for trabecular and cortical human bones, indicating a good match of the micromechanical properties for their potential use for bone repair. The stiffness of the biocomposites was confirmed to gradate-compliant cement matrix, cement-filler interface, and stiff filler-as a result of the structuring at the nanometer-micrometer level. This architecture is critical in conditioning the final mechanical properties of the functional composite biomaterial. In vitro cell culture experiments showed that the developed biomaterial system is noncytotoxic.

Degradation of strength properties of epoxy resin filled with natural-based particles

NASA Astrophysics Data System (ADS)

Valášek, Petr; Habrová, Karolína; Müller, Miroslav

2018-05-01

Degradation of polymeric materials can be considered as a limiting factor for their use. Mechanical characteristics of epoxy resins are reduced, for example, by the action and changes of temperature or humidity. Degradation also occurs in composite systems where the epoxy resins function as matrices, i.e. in polymer composite materials. If a natural filler is used together with the epoxy resin, we refer to these materials as biocomposites, where also the natural character of the filler material greatly affects the degradation process. The paper focuses on the description of the shear strength of the resin filled with particles prepared from the seeds of dates of Phoenix Dactylifera plant. The degradation was evaluated experimentally in laboratory conditions via the climatic chamber. The experiment describes composites with a particle size of filler 100-200 μm with a concentration of 5 - 10 wt%. As the number of degradation cycles increased, the tensile strength of both the unfilled and the filled epoxy resin decreased. After 5 weeks, the drop was up to 50%. The presence of the particles did not significantly affect the shear strength compared to the non-filled resin. The described way of utilization of the natural-based particles is the possibility of material utilization of secondary natural materials.

Structured block copolymer thin film composites for ultra-high energy density capacitors

NASA Astrophysics Data System (ADS)

Samant, Saumil; Hailu, Shimelis; Grabowski, Christopher; Durstock, Michael; Raghavan, Dharmaraj; Karim, Alamgir

2014-03-01

Development of high energy density capacitors is essential for future applications like hybrid vehicles and directed energy weaponry. Fundamentally, energy density is governed by product of dielectric permittivity ɛ and breakdown strength Vbd. Hence, improvements in energy density are greatly reliant on improving either ɛ or Vbd or a combination of both. Polymer films are widely used in capacitors due to high Vbd and low loss but they suffer from very low permittivities. Composite dielectrics offer a unique opportunity to combine the high ɛ of inorganic fillers with the high Vbd of a polymer matrix. For enhancement of dielectric properties, it is essential to improve matrix-filler interaction and control the spatial distribution of fillers for which nanostructured block copolymers BCP act as ideal templates. We use Directed Self-assembly of block copolymers to rapidly fabricate highly aligned BCP-TiO2 composite nanostructures in thin films under dynamic thermal gradient field to synergistically combine the high ɛ of functionalized TiO2 and high Vbd of BCP matrix. The results of impact of BCP morphology, processing conditions and concentration of TiO2 on capacitor performance will be reported. U.S. Air Force of Scientific Research under contract FA9550-12-1-0306

Mechanical behavior of bioactive composite cements consisting of resin and glass-ceramic powder in a simulated body fluid: effect of silane coupling agent.

PubMed

Miyata, N; Matsuura, W; Kokubo, T; Nakamura, T

2004-09-01

Time-dependent strength behavior was investigated for bisphenol-a-glycidyl methacrylate/triethylene glycol dimethacrylate (Bis-GMA/TEGDMA) resin cements combined with glass-ceramic A-W filler treated with various kinds of silane coupling agents. The fracture strength of the composite resin cements was measured by three-point bending as a function of stressing rate in a simulated body fluid (SBF), and thereby the stress-corrosion susceptibility constant was evaluated. The fracture strength was found to depend on the kind of coupling agent used. For the present Bis-GMA/TEGDMA resin, the silane coupling agents without hydrophilic amine groups can be used to obtain good adhesion between resin and A-W filler owing to their nature of co-polymerizing with the resin. On the other hand, all the composite resin cements showed nearly the same degree of stress-corrosion susceptibility whether the A-W fillers were treated or untreated with silane coupling agents. This means that the stress-corrosion susceptibility of the present composite cements is predominantly affected by that of the matrix resin. Thus, the microcrack formation and growth at the resin matrix near particle - resin interface were thought to determine overall time-dependent strength behavior of the composite cements.

Adjustable high emittance gap filler. [reentry shielding for space shuttle vehicles

NASA Technical Reports Server (NTRS)

Leiser, D. B.; Stewart, D. A.; Smith, M.; Estrella, C. A.; Goldstein, H. E. (Inventor)

1981-01-01

A flexible, adjustable refractory filler is disclosed for filling gaps between ceramic tiles forming the heat shield of a space shuttle vehicle, to protect its aluminum skin during atmospheric reentry. The easily installed and replaced filler consists essentially of a strip of ceramic cloth coated, at least along both its longitudinal edges with a room temperature vulcanizable silicone rubber compound with a high emittance colored pigment. The filler may have one or more layers as the gap width requires. Preferred materials are basket weave aluminoborosilicate cloth, and a rubber compounded with silicon tetraboride as the emittance agent and finely divided borosilicate glass containing about 7.5% B2O3 as high temperature binder. The filler cloth strip or tape is cut to proper width and length, inserted into the gap, and fastened with previously applied drops of silicone rubber adhesive.

Corrosion behavior in high-temperature pressurized water of Zircaloy-4 joints brazed with Zr-Cu-based amorphous filler alloys

NASA Astrophysics Data System (ADS)

Lee, Jung Gu; Lee, Gyoung-Ja; Park, Jin-Ju; Lee, Min-Ku

2017-05-01

The compositional effects of ternary Zr-Cu-X (X: Al, Fe) amorphous filler alloys on galvanic corrosion susceptibility in high-temperature pressurized water were investigated for Zircaloy-4 brazed joints. Through an Al-induced microgalvanic reaction that deteriorated the overall nobility of the joint, application of the Zr-Cu-Al filler alloy caused galvanic coupling to develop readily between the Al-bearing joint and the Al-free base metal, finally leading to massive localized corrosion of the joint. Contrastingly, joints prepared with a Zr-Cu-Fe filler alloy showed excellent corrosion resistance comparable to that of the Zircaloy-4 base metal, since the Cu and Fe elements forming fine intermetallic particles with Zr did not influence the electrochemical stability of the resultant joints. The present results demonstrate that Fe is a more suitable alloying element than Al for brazing filler alloys subjected to high-temperature corrosive environments.

Structural analysis of strontium in human teeth treated with surface pre-reacted glass-ionomer filler eluate by using extended X-ray absorption fine structure analysis.

PubMed

Uo, Motohiro; Wada, Takahiro; Asakura, Kiyotaka

2017-03-31

The bioactive effects of strontium released from surface pre-reacted glass-ionomer (S-PRG) fillers may aid in caries prevention. In this study, the local structure of strontium taken up by teeth was estimated by extended X-ray absorption fine structure analysis. Immersing teeth into S-PRG filler eluate increased the strontium content in enamel and dentin by more than 100 times. The local structure of strontium in enamel and dentin stored in distilled water was the same as that in synthetic strontium-containing hydroxyapatite (SrHAP). Moreover, the local structure of strontium in enamel and dentin after immersion in the S-PRG filler eluate was also similar to that of SrHAP. After immersion in the S-PRG filler eluate, strontium was suggested to be incorporated into the hydroxyapatite (HAP) of enamel and dentin at the calcium site in HAP.

Dielectric properties of inorganic fillers filled epoxy thin film

DOE Office of Scientific and Technical Information (OSTI.GOV)

Norshamira, A., E-mail: myra.arshad@gmail.com; Mariatti, M., E-mail: mariatti@usm.my

2015-07-22

The demand on the small size and high performance electronics has driven changes in the electronic packaging requirements from discrete capacitor to embedded capacitor. Embedded capacitor can improve electrical performance compared with discrete capacitor. This study aimed to achieve high dielectric of epoxy thin film composite that were targeted for application as embedded capacitor. In this study, inorganic fillers such as Calcium Copper Titanate (CCTO), Iron(III) Oxide (Fe{sub 2}O{sub 3}) and Titanium Dioxide (TiO{sub 2}) were loaded in epoxy system at 5 and 20vol%. Morphology and dielectric properties were investigated to identify the effect of fillers loading and types ofmore » fillers on the properties of epoxy thin film composite. Based on the study, CCTO with 20vol% loading was found to have good dielectric properties compared to other type of fillers.« less

Dilution in single pass arc welds

DOE Office of Scientific and Technical Information (OSTI.GOV)

DuPont, J.N.; Marder, A.R.

1996-06-01

A study was conducted on dilution of single pass arc welds of type 308 stainless steel filler metal deposited onto A36 carbon steel by the plasma arc welding (PAW), gas tungsten arc welding (GTAW), gas metal arc welding (GMAW), and submerged arc welding (SAW) processes. Knowledge of the arc and melting efficiency was used in a simple energy balance to develop an expression for dilution as a function of welding variables and thermophysical properties of the filler metal and substrate. Comparison of calculated and experimentally determined dilution values shows the approach provides reasonable predictions of dilution when the melting efficiencymore » can be accurately predicted. The conditions under which such accuracy is obtained are discussed. A diagram is developed from the dilution equation which readily reveals the effect of processing parameters on dilution to aid in parameter optimization.« less

New Class of Thermal Interface Materials Delivers Ultralow Thermal

Science.gov Websites

chemical integration of boron nitride nanosheets (BNNS), soft organic linkers, and a copper matrix functionalized with soft organic linkers and a copper matrix. Researchers selected BNNS as a filler due to its metal/organic/inorganic hybrid nanocomposites provide a promising start to a thermal management solution

Formulaic Language in Parkinson's Disease and Alzheimer's Disease: Complementary Effects of Subcortical and Cortical Dysfunction

ERIC Educational Resources Information Center

Van Lancker Sidtis, Diana; Choi, JiHee; Alken, Amy; Sidtis, John J.

2015-01-01

Purpose: The production of formulaic expressions (conversational speech formulas, pause fillers, idioms, and other fixed expressions) is excessive in the left hemisphere and deficient in the right hemisphere and in subcortical stroke. Speakers with Alzheimer's disease (AD), having functional basal ganglia, reveal abnormally high proportions of…

A 3D-Printable Polymer-Metal Soft-Magnetic Functional Composite-Development and Characterization.

PubMed

Khatri, Bilal; Lappe, Karl; Noetzel, Dorit; Pursche, Kilian; Hanemann, Thomas

2018-01-25

In this work, a 3D printed polymer-metal soft-magnetic composite was developed and characterized for its material, structural, and functional properties. The material comprises acrylonitrile butadiene styrene (ABS) as the polymer matrix, with up to 40 vol. % stainless steel micropowder as the filler. The composites were rheologically analyzed and 3D printed into tensile and flexural test specimens using a commercial desktop 3D printer. Mechanical characterization revealed a linearly decreasing trend of the ultimate tensile strength (UTS) and a sharp decrease in Young's modulus with increasing filler content. Four-point bending analysis showed a decrease of up to 70% in the flexural strength of the composite and up to a two-factor increase in the secant modulus of elasticity. Magnetic hysteresis characterization revealed retentivities of up to 15.6 mT and coercive forces of up to 4.31 kA/m at an applied magnetic field of 485 kA/m. The composite shows promise as a material for the additive manufacturing of passive magnetic sensors and/or actuators.

A 3D-Printable Polymer-Metal Soft-Magnetic Functional Composite—Development and Characterization

PubMed Central

Lappe, Karl; Noetzel, Dorit; Pursche, Kilian; Hanemann, Thomas

2018-01-01

In this work, a 3D printed polymer–metal soft-magnetic composite was developed and characterized for its material, structural, and functional properties. The material comprises acrylonitrile butadiene styrene (ABS) as the polymer matrix, with up to 40 vol. % stainless steel micropowder as the filler. The composites were rheologically analyzed and 3D printed into tensile and flexural test specimens using a commercial desktop 3D printer. Mechanical characterization revealed a linearly decreasing trend of the ultimate tensile strength (UTS) and a sharp decrease in Young’s modulus with increasing filler content. Four-point bending analysis showed a decrease of up to 70% in the flexural strength of the composite and up to a two-factor increase in the secant modulus of elasticity. Magnetic hysteresis characterization revealed retentivities of up to 15.6 mT and coercive forces of up to 4.31 kA/m at an applied magnetic field of 485 kA/m. The composite shows promise as a material for the additive manufacturing of passive magnetic sensors and/or actuators. PMID:29370112

A methodological evaluation and predictive in silico investigation into the multi-functionality of arginine in directly compressed tablets.

PubMed

ElShaer, Amr; Kaialy, Waseem; Akhtar, Noreen; Iyire, Affiong; Hussain, Tariq; Alany, Raid; Mohammed, Afzal R

2015-10-01

The acceleration of solid dosage form product development can be facilitated by the inclusion of excipients that exhibit poly-/multi-functionality with reduction of the time invested in multiple excipient optimisations. Because active pharmaceutical ingredients (APIs) and tablet excipients present diverse densification behaviours upon compaction, the involvement of these different powders during compaction makes the compaction process very complicated. The aim of this study was to assess the macrometric characteristics and distribution of surface charges of two powders: indomethacin (IND) and arginine (ARG); and evaluate their impact on the densification properties of the two powders. Response surface modelling (RSM) was employed to predict the effect of two independent variables; Compression pressure (F) and ARG percentage (R) in binary mixtures on the properties of resultant tablets. The study looked at three responses namely; porosity (P), tensile strength (S) and disintegration time (T). Micrometric studies showed that IND had a higher charge density (net charge to mass ratio) when compared to ARG; nonetheless, ARG demonstrated good compaction properties with high plasticity (Y=28.01MPa). Therefore, ARG as filler to IND tablets was associated with better mechanical properties of the tablets (tablet tensile strength (σ) increased from 0.2±0.05N/mm(2) to 2.85±0.36N/mm(2) upon adding ARG at molar ratio of 8:1 to IND). Moreover, tablets' disintegration time was shortened to reach few seconds in some of the formulations. RSM revealed tablet porosity to be affected by both compression pressure and ARG ratio for IND/ARG physical mixtures (PMs). Conversely, the tensile strength (σ) and disintegration time (T) for the PMs were influenced by the compression pressure, ARG ratio and their interactive term (FR); and a strong correlation was observed between the experimental results and the predicted data for tablet porosity. This work provides clear evidence of the multi-functionality of ARG as filler, binder and disintegrant for directly compressed tablets. Copyright © 2015 Elsevier B.V. All rights reserved.

Multiscale analysis of the radiooxidative degradation of EVA/EPDM composites. ATH filler and dose rate effect

NASA Astrophysics Data System (ADS)

Sidi, Ahmedou; Colombani, Juliette; Larché, Jean-François; Rivaton, Agnès

2018-01-01

This study is focused on the radiooxidative degradation of polymeric insulation of electric cables used in Nuclear Power Plants (NPPs). In order to investigate the degradation mechanisms of the insulation, model composites with ATH (Aluminium TriHydrate) filler and blends (without filler) based on a cross-linked mixture of EVA (Ethylene Vinyl Acetate) and EPDM (Ethylene Propylene Diene Monomer) were submitted to gamma-rays. In normal operating conditions of a NPP, the dose rate which electric cables are exposed to is around 0.1 Gy h-1. In this work, artificial accelerated ageing test process has been applied at a relatively low dose rate of 7 Gy h-1. Gamma-irradiations at higher dose rates typically used to accelerate the ageing, in the range 0.2-1 kGy h-1, were also carried out. The first part of the study is focused on irradiations performed at relatively low dose rate and is devoted to the highlighting of the radiooxidative degradation mechanisms of EVA/EPDM blend with and without ATH filler. Correlations between the evolutions of the chemical, morphological and mechanical/electrical properties of the materials occurring after the ageing process are presented. It is shown that the degradation process is governed by radical oxidation mechanism involving chain scissions leading to the formation of carboxylic acids as end-groups. One of the main effects of the ATH filler is the progressive loss of the mechanical properties of the composite upon radiooxidation whereas they are maintained in the case of the unfilled sample. Despite the oxidation of the polymer, no change in the electrical properties of the blend and of the composite could be observed. The second part of the study focuses on the dose rate effect. It is shown that one of the main consequences of an increase of the dose rate from 7 Gy h-1 to 0.2-1 kGy h-1 is a reduction of the chain scission process yield by a factor of about 20. Therefore, an important and consistent finding is that there are some limits that must not be exceeded in terms of dose rate to ensure a global satisfactorily representativeness of the accelerated ageing process.

Comparison of Spontaneously Elicited Language Patterns in Specific Language Impairment and High-Functioning Autism.

PubMed

Craig, Megan; Trauner, Doris

2018-02-01

We aimed to characterize differences in the use of language in children with specific language impairment and high-functioning autism by analyzing verbal responses on standardized tests. The overall goal was to provide clinicians with additional tools with which to aid in distinguishing the two neurodevelopmental disorders. This study included 16 children with specific language impairment, 28 children with high-functioning autism, and 52 typically developing participants between the ages of six and 14. Groups were matched for age, and specific language impairment and high-functioning autism groups were matched on verbal and performance IQ. Responses from standardized tests were examined for response length, grammatical errors, filler words, perseverations, revisions (repeated attempts to begin or continue a sentence), off-topic attention shifts (lapses in attention to the task), and rambling. Data were analyzed using parametric and nonparametric methods. Specific language impairment responses were longer and contained more filler words than did those of the other two groups, whereas high-functioning autism responses exhibited more grammatical errors, off-topic attention shifts, and rambling. Specific language impairment and high-functioning autism responses showed higher rates of perseveration compared with controls. There were no significant differences in revisions among the three groups. Differences in language patterns of participants with specific language impairment and high-functioning autism may be useful to the clinician in helping to differentiate isolated language impairment from high-functioning autism. The results also support the conclusion that the two conditions are separable, and each exhibits a different pattern of language dysfunction. Copyright © 2017 Elsevier Inc. All rights reserved.

Silicone nanocomposite coatings for fabrics

NASA Technical Reports Server (NTRS)

Lee, Stein S. (Inventor); Ou, Runqing (Inventor); Eberts, Kenneth (Inventor); Singhal, Amit (Inventor)

2011-01-01

A silicone based coating for fabrics utilizing dual nanocomposite fillers providing enhanced mechanical and thermal properties to the silicone base. The first filler includes nanoclusters of polydimethylsiloxane (PDMS) and a metal oxide and a second filler of exfoliated clay nanoparticles. The coating is particularly suitable for inflatable fabrics used in several space, military, and consumer applications, including airbags, parachutes, rafts, boat sails, and inflatable shelters.

Effect of inorganic fillers in paper on the adhesion of pressure-sensitive adhesives

Treesearch

Weixu Chen; Xiaoyan Tang; John Considine; Kevin T. Turner

2011-01-01

Inorganic fillers are inexpensive materials used to increase the density, smoothness and other properties of paper that are important for printing. In the current study, the adhesion of pressure-sensitive adhesives (PSAs), a common type of adhesive used in labels and tapes, to papers containing varying amounts and types of fillers is investigated. Papers with three...

Evaluation of micron-sized wood and bark particles as filler in thermoplastic composites

Treesearch

David P. Harper; Thomas L. Eberhardt

2010-01-01

Micron-sized particles, prepared from loblolly pine (Pinus taeda L.) wood and bark, were evaluated for use in wood-plastic composites (WPCs). Particles were also prepared from hard (periderm) and soft (obliterated phloem) components in the bark and compared to whole wood (without bark) filler commonly used by the WPC industry. All bark fillers had...

Detection of percolating paths in polyhedral segregated network composites using electrostatic force microscopy and conductive atomic force microscopy

NASA Astrophysics Data System (ADS)

Waddell, J.; Ou, R.; Capozzi, C. J.; Gupta, S.; Parker, C. A.; Gerhardt, R. A.; Seal, K.; Kalinin, S. V.; Baddorf, A. P.

2009-12-01

Composite specimens possessing polyhedral segregated network microstructures require a very small amount of nanosize filler, <1 vol %, to reach percolation because percolation occurs by accumulation of the fillers along the edges of the deformed polymer matrix particles. In this paper, electrostatic force microscopy (EFM) and conductive atomic force microscopy (C-AFM) were used to confirm the location of the nanosize fillers and the corresponding percolating paths in polymethyl methacrylate/carbon black composites. The EFM and C-AFM images revealed that the polyhedral polymer particles were coated with filler, primarily on the edges as predicted by the geometric models provided.

The use of Ni-Cr-Si-Be filler metals for brazing of stainless steels

NASA Astrophysics Data System (ADS)

Ivannikov, A.; Fedotov, V.; Suchkov, A.; Penyaz, M.; Fedotov, I.; Tarasov, B.

2016-04-01

Nanocrystalline ribbon filler metal-alloys of system Ni-Cr-Si-Be are produced by the rapidly quenching of the melt method. By these filler metals carried out hight temperature vacuum brazing of austenitic steels (12Kh18N10T and Kh18N8G2) and austenitic-ferritic class EI-811 (12Kh21N5T). The basic laws of structure-phase state foundation of brazed joints are determined, features of the interaction of the molten filler metal to the brazed materials are identified, the optimal temperature and time parameters of the brazing process are determined.

Method for controlling brazing

DOEpatents

Hosking, F Michael [Albuquerque, NM; Hall, Aaron C [Albuquerque, NM; Givler, Richard C [Albuquerque, NM; Walker, Charles A [Albuquerque, NM

2006-08-01

A method for making a braze joint across a discontinuity in a work piece using alternating current. A filler metal is pre-placed at a location sufficiently close to the discontinuity such that, when an alternating current is applied across a work piece to heat the work piece and melt the filler metal, the filler metal is drawn into the discontinuity. The alternating current is maintained for a set residence time, generally less than 10 seconds and more particularly less than 3 seconds. The alternating current is then altered, generally by reducing the current and/or voltage such that the filler metal can solidify to form a braze joint of desired quality and thickness.

Blindness caused by cosmetic filler injection: a review of cause and therapy.

PubMed

Carruthers, Jean D A; Fagien, Steve; Rohrich, Rod J; Weinkle, Susan; Carruthers, Alastair

2014-12-01

Vascular occlusion causing blindness is a rare yet greatly feared complication of the use of facial aesthetic fillers. The authors performed a review of the aesthetic literature to ascertain the reported cases of blindness and the literature reporting variations in the vascular anatomy of the human face. The authors suggest a small but potentially helpful addition to the accepted management of the acute case. Cases of blindness, mostly irreversible, from aesthetic filler injections have been reported from Asia, Europe, and North America. Autologous fat appears to be the most frequent filler causing blindness. Some cases of partial visual recovery have been reported with hyaluronic acid and calcium hydroxylapatite fillers. The sudden profusion of new medical and nonmedical aesthetic filler injectors raises a new cause for alarm about patient safety. The published reports in the medical literature are made by experienced aesthetic surgeons and thus the actual incidence may be even higher. Also, newer injectors may not be aware of the variations in the pattern of facial vascular arborization. The authors present a summary of the relevant literature to date and a suggested helpful addition to the protocols for urgent management.

Electrical modulus analysis on the Ni/CCTO/PVDF system near the percolation threshold

NASA Astrophysics Data System (ADS)

Yang, Wenhu; Yu, Shuhui; Sun, Rong; Ke, Shanming; Huang, Haitao; Du, Ruxu

2011-11-01

A type of Ni/CCTO/PVDF three-phase percolative composite was prepared, in which the filler content (volume fraction) of Ni and CCTO was set at 60 vol%. The dependence of permittivity, electrical modulus and ac conductivity on the concentration of Ni and CCTO fillers near the percolation threshold was investigated in detail. The permittivity of the composites dramatically increased as the Ni content approached 24 vol%. This unique physical mechanism was realized as the formation of conductive channels near the percolation threshold. Analysis on the electrical modulus showed that the conductive channels are governed by three relaxation processes induced by the fillers (Ni, CCTO) and PVDF matrix, which are the interfacial polarization derived from the interfaces between fillers (Ni, CCTO) and PVDF matrix, and the polarization of CCTO ceramic filler and PVDF matrix. The conductivity behaviour with various Ni loadings and temperature suggested that the transition from an insulating to a conducting state should be induced by charge tunnelling between Ni-Ni particles, Ni-CCTO fillers and Ni-PVDF matrix. These findings demonstrated that the tunnelling conduction in the composite can be attributed to the unique physical mechanism near the percolation threshold.

Three-dimensional remodeling of young Asian women's faces using 20-mg/ml smooth, highly cohesive, viscous hyaluronic acid fillers: a retrospective study of 320 patients.

PubMed

Bae, Jung Min; Lee, Dong Won

2013-09-01

Because Asian faces are generally flatter than Caucasian faces, Asian women are increasingly requesting facial volume enhancement. To clarify the effectiveness and safety of a volumizing treatment using 20-mg/mL smooth, highly cohesive, viscous hyaluronic acid fillers in young Asian women. We retrospectively reviewed 320 patients who had been treated with this filler from March 2010 to February 2012. The filler was injected in the shape of a diamond to the glabella, both malar eminences, and chin. Overall, 4 to 6 mL of filler was sufficient to enhance the volume of a face in young Asian women. Both the physicians and patients rated effectiveness on the Global Aesthetic Improvement Scale at week 4. Need for touch-up and any adverse events were also evaluated. Most patients were very satisfied with this volumizing procedure, and there were no major complications. The 20-mg/mL smooth, highly cohesive, viscous hyaluronic acid filler is an effective, well-tolerated treatment option in young Asian women wishing for a more-three-dimensional profile. © 2013 by the American Society for Dermatologic Surgery, Inc. Published by Wiley Periodicals, Inc.

Characteristics comparison of weld metal zones welded to cast and forged steels for piston crown material

NASA Astrophysics Data System (ADS)

Moon, Kyung-Man; Kim, Yun-Hae; Lee, Myeong-Hoon; Baek, Tae-Sil

2015-03-01

An optimum repair welding for the piston crown which is one of the engine parts exposed to the combustion chamber is considered to be very important to prolong the engine lifetime from an economical point of view. In this study, two types of filler metals such as 1.25Cr-0.5Mo, 0.5Mo were welded with SMAW method and the other two types of filler metals such as Inconel 625 and 718 were welded with GTAW method, respectively, and the used base metals were the cast and forged steels of the piston crown material. The weld metal zones welded with Inconel 625 and 718 filler metals exhibited higher corrosion resistance compared to 1.25Cr-0.5Mo and 0.5Mo filler metals. In particular, the weld metal zone welded with Inconel 718 and 0.5Mo, filler metals indicated the best and worst corrosion resistance, respectively. Consequently, it is suggested that the corrosion resistance of the weld metal zone surely depends on the chemical components of each filler metal and welding method irrespective of the types of piston crown material.

Primary Nonadherence, Associated Clinical Outcomes, and Health Care Resource Use Among Patients with Rheumatoid Arthritis Prescribed Treatment with Injectable Biologic Disease-Modifying Antirheumatic Drugs.

PubMed

Harnett, James; Wiederkehr, Daniel; Gerber, Robert; Gruben, David; Bourret, Jeffrey; Koenig, Andrew

2016-03-01

Adherence to biologic disease-modifying antirheumatic drugs (bDMARDs) among patients with rheumatoid arthritis (RA) is often suboptimal in routine clinical practice. Low or nonadherence can reduce the effectiveness of bDMARD therapies. To evaluate filling of newly prescribed initial bDMARDs for the treatment of RA and evaluate potential for characterizing treatment decisions and patient outcomes. In this retrospective cohort analysis, patients aged ≥ 18 years with an RA diagnosis (ICD-9-CM code 714.xx) were selected from a de-identified database of clinical information from the Electronic Health Record (EHR; Humedica) database linked to health care claims (Optum) from commercial and Medicare Advantage health plans (2007-2013). The first biologic prescription date in EHR was the index date. Patients were categorized as filling the prescription within 30 days (early fillers), 31-180 days (late fillers), or not at all within 180 days (nonfillers) of index date. Of 373 patients meeting inclusion criteria, 170 (45.6%), 59 (15.8%), and 144 (38.6%) were categorized as early fillers, late fillers, and nonfillers, respectively. Most prescriptions were written or ordered for tumor necrosis factor inhibitors (88.7%). Compared with late and nonfillers, early fillers were younger and more likely to be female, with higher pain scores (among those reporting pain scores) and RA severity scores pre-index, and filled more prescriptions for any reason pre-index. More nonfillers (66.0%) were Medicare patients than early (17.7%) and late (35.6%) fillers. During days 0-30 post-index, conventional synthetic DMARD use was greatest for early fillers (45.9%) and lowest among nonfillers (24.3%); however, during days 31-180 post-index, the proportion was highest for late fillers (61.0%) and lowest for nonfillers (35.4%). Of early fillers, 12.9% did not fill/receive a bDMARD after 30 days. Only 23 patients had pre/post-index pain scores, and 47 patients had a rationale for stopping or not filling a bDMARD. In patients with pharmacy and medical coverage for 180 days post-index, early fillers had greater RA-related pharmacy and medical resource use and costs than late and nonfillers combined. These findings confirm a high rate of primary nonadherence to bDMARDs among patients with RA.

Rethinking the Role of Nitroglycerin Ointment in Ischemic Vascular Filler Complications: An Animal Model With ICG Imaging.

PubMed

Hwang, Catherine J; Morgan, Payam V; Pimentel, Aline; Sayre, James W; Goldberg, Robert A; Duckwiler, Gary

2016-01-01

Soft tissue dermal fillers, both temporary and permanent, are used frequently in facial rejuvenation. As the use of fillers increases, ischemic complications including skin necrosis are becoming more prevalent. In the literature, topical nitroglycerin paste has been recommended in the early treatment of patients presenting with ischemia. The purpose of this study was to evaluate the vascular perfusion effects of topical nitroglycerin paste in an animal model using indocyanine green (ICG) imaging. After Animal Research Committee approval, a rabbit ear model was used to create filler-associated skin ischemia. Ischemia was confirmed to occur after intra-arterial occlusion. Four commonly used soft tissue fillers were injected intra-arterially: Radiesse (Merz USA, Greensboro NC), Restylane (Galderma, Ft. Worth, TX), Juvederm Ultra (Allergan, Irvine CA), Belotero (Merz USA, Greensboro NC) (0.1 ml). A total of 15 ears were used, 1 control and 4 experimental per product. Thirty minutes after occlusion, nitroglycerin ointment USP, 2%(Nitro-Bid) was applied topically to the experimental ears. Vascular perfusion was evaluated with the SPY System (Novadaq Inc.) using ICG imaging. Perfusion images were obtained at baseline, immediately after, and 30 minutes after intra-arterial filler injection, and at 30, 60, 90, and 120 minutes after application of topical nitroglycerin ointment. In this rabbit ear model, no statistically significant improvement in perfusion was noted after topical application of nitroglycerin paste with ICG imaging. In addition, the skin of the rabbit ear post-nitroglycerin ointment appeared to have more of a congested appearance than the controls. Ischemic filler complications are becoming increasingly prevalent. Practitioners often treat these complications with topical nitroglycerin paste based on the knowledge that topical nitroglycerin causes vasodilation. In filler-induced tissue ischemia, however, filler product is present within arterioles. Theoretically, applying nitroglycerin paste, at least early, may not improve perfusion and could worsen ischemia with dilation of vessels and further propagation of product into the smaller arterioles and capillaries. In addition, nitroglycerin paste has systemic effects, including hypotension and dizziness, which may not be tolerated by some patients. Therefore, the authors caution the use of topical nitroglycerin paste in patients presenting with filler-associated ischemia. Further studies in the best treatment algorithms for patients presenting with ischemic complications need to be performed.

A Comparative Study of Fracture Toughness at Cryogenic Temperature of Austenitic Stainless Steel Welds

NASA Astrophysics Data System (ADS)

Aviles Santillana, I.; Boyer, C.; Fernandez Pison, P.; Foussat, A.; Langeslag, S. A. E.; Perez Fontenla, A. T.; Ruiz Navas, E. M.; Sgobba, S.

2018-03-01

The ITER magnet system is based on the "cable-in-conduit" conductor (CICC) concept, which consists of stainless steel jackets filled with superconducting strands. The jackets provide high strength, limited fatigue crack growth rate and fracture toughness properties to counteract the high stress imposed by, among others, electromagnetic loads at cryogenic temperature. Austenitic nitrogen-strengthened stainless steels have been chosen as base material for the jackets of the central solenoid and the toroidal field system, for which an extensive set of cryogenic mechanical property data are readily available. However, little is published for their welded joints, and their specific performance when considering different combinations of parent and filler metals. Moreover, the impact of post-weld heat treatments that are required for Nb3Sn formation is not extensively treated. Welds are frequently responsible for cracks initiated and propagated by fatigue during service, causing structural failure. It becomes thus essential to select the most suitable combination of parent and filler material and to assess their performance in terms of strength and crack propagation at operation conditions. An extensive test campaign has been conducted at 7 K comparing tungsten inert gas (TIG) welds using two fillers adapted to cryogenic service, EN 1.4453 and JK2LB, applied to two different base metals, AISI 316L and 316LN. A large set of fracture toughness data are presented, and the detrimental effect on fracture toughness of post-weld heat treatments (unavoidable for some of the components) is demonstrated. In this study, austenitic stainless steel TIG welds with various filler metals have undergone a comprehensive fracture mechanics characterization at 7 K. These results are directly exploitable and contribute to the cryogenic fracture mechanics properties database of the ITER magnet system. Additionally, a correlation between the impact in fracture toughness and microstructure resulting from the above treatment is provided.

Morphologies, Processing and Properties of Ceramic Foams and Their Potential as TPS Materials

NASA Technical Reports Server (NTRS)

Stackpoole, Mairead; Simoes, Conan R.; Johnson, Sylvia M.

2002-01-01

The current research is focused on processing ceramic foams with compositions that have potential as a thermal protection material. The use of pre-ceramic polymers with the addition of sacrificial blowing agents or sacrificial fillers offers a viable approach to form either open or closed cell insulation. Our work demonstrates that this is a feasible method to form refractory ceramic foams at relatively low processing temperatures. It is possible to foam complex shapes then pyrolize the system to form a ceramic while retaining the shape of the unfired foam. Initial work focused on identifying suitable pre-ceramic polymers with desired properties such as ceramic yield and chemical make up of the pyrolysis product after firing. We focused on making foams in the Si system (Sic, Si02, Si-0-C), which is in use in current acreage TPS systems. Ceramic foams with different architectures were formed from the pyrolysis of pre-ceramic polymers at 1200 C in different atmospheres. In some systems a sacrificial polyurethane was used as the blowing agent. We have also processed foams using sacrificial fillers to introduce controlled cell sizes. Each sacrificial filler or blowing agent leads to a unique morphology. The effect of different fillers on foam morphologies and the characterization of these foams in terms of mechanical and thermal properties are presented. We have conducted preliminary arc jet testing on selected foams with the materials being exposed to typical re-entry conditions for acreage TPS and these results will be discussed. Foams processed using these approaches have bulk densities ranging from 0.15 to 0.9 g/cm3 and cell sizes ranging from 5 to 500 pm. Compression strengths ranged from 2 to 7 MPa for these systems. Finally, preliminary oxidation studies have been conducted on selected systems and will be discussed.

Polylactic acid composites incorporating casein functionalized cellulose nanowhiskers

PubMed Central

2013-01-01

Background Polylactic acid (PLA) is considered to be a sustainable alternative to petroleum-based polymers for many applications. Using cellulose fiber to reinforce PLA is of great interest recently due to its complete biodegradability and potential improvement of the mechanical performance. However, the dispersion of hydrophilic cellulose fibers in the hydrophobic polymer matrix is usually poor without using hazardous surfactants. The goal of this study was to develop homogenously dispersed cellulose nanowhisker (CNW) reinforced PLA composites using whole milk casein protein, which is an environmentally compatible dispersant. Results In this study, whole milk casein was chosen as a dispersant in the PLA-CNW system because of its potential to interact with the PLA matrix and cellulose. The affinity of casein to PLA was studied by surface plasmon resonance (SPR) imaging. CNWs were functionalized with casein and used as reinforcements to make PLA composites. Fluorescent staining of CNWs in the PLA matrix was implemented as a novel and simple way to analyze the dispersion of the reinforcements. The dispersion of CNWs in PLA was improved when casein was present. The mechanical properties of the composites were studied experimentally. Compared to pure PLA, the PLA composites had higher Young’s modulus. Casein (CS) functionalized CNW reinforced PLA (PLA-CS-CNW) at 2 wt% filler content maintained higher strain at break compared to normal CNW reinforced PLA (PLA-CNW). The Young’s modulus of PLA-CS-CNW composites was also higher than that of PLA-CNW composites at higher filler content. However, all composites exhibited lower strain at break and tensile strength at high filler content. Conclusions The presence of whole milk casein improved the dispersion of CNWs in the PLA matrix. The improved dispersion of CNWs provided higher modulus of the PLA composites at higher reinforcement loading and maintained the strain and stress at break of the composites at relatively low reinforcement loading. The affinity of the dispersant to PLA is important for the ultimate strength and stiffness of the composites. PMID:24341897

Innovative Self-Healing Seals for Solid Oxide Fuel Cells (SOFC)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Raj Singh

Solid oxide fuel cell (SOFC) technology is critical to several national initiatives. Solid State Energy Conversion Alliance (SECA) addresses the technology needs through its comprehensive programs on SOFC. A reliable and cost-effective seal that works at high temperatures is essential to the long-term performance of the SOFC for 40,000 hours at 800°C. Consequently, seals remain an area of highest priority for the SECA program and its industry teams. An innovative concept based on self-healing glasses was advanced and successfully demonstrated through seal tests for 3000 hours and 300 thermal cycles to minimize internal stresses under both steady state and thermalmore » transients for making reliable seals for the SECA program. The self-healing concept requires glasses with low viscosity at the SOFC operating temperature of 800°C but this requirement may lead to excessive flow of the glass in areas forming the seal. To address this challenge, a modification to glass properties by addition of particulate fillers is pursued in the project. The underlying idea is that a non-reactive ceramic particulate filler is expected to form glass-ceramic composite and increase the seal viscosity thereby increasing the creep resistance of the glass-composite seals under load. The objectives of the program are to select appropriate filler materials for making glass-composite, fabricate glass-composites, measure thermal expansion behaviors, and determine stability of the glass-composites in air and fuel environments of a SOFC. Self-healing glass-YSZ composites are further developed and tested over a longer time periods under conditions typical of the SOFCs to validate the long-term stability up to 2000 hours. The new concepts of glass-composite seals, developed and nurtured in this program, are expected to be cost-effective as these are based on conventional processing approaches and use of the inexpensive materials.« less

Multi-scale analysis of the effect of nano-filler particle diameter on the physical properties of CAD/CAM composite resin blocks.

PubMed

Yamaguchi, Satoshi; Inoue, Sayuri; Sakai, Takahiko; Abe, Tomohiro; Kitagawa, Haruaki; Imazato, Satoshi

2017-05-01

The objective of this study was to assess the effect of silica nano-filler particle diameters in a computer-aided design/manufacturing (CAD/CAM) composite resin (CR) block on physical properties at the multi-scale in silico. CAD/CAM CR blocks were modeled, consisting of silica nano-filler particles (20, 40, 60, 80, and 100 nm) and matrix (Bis-GMA/TEGDMA), with filler volume contents of 55.161%. Calculation of Young's moduli and Poisson's ratios for the block at macro-scale were analyzed by homogenization. Macro-scale CAD/CAM CR blocks (3 × 3 × 3 mm) were modeled and compressive strengths were defined when the fracture loads exceeded 6075 N. MPS values of the nano-scale models were compared by localization analysis. As the filler size decreased, Young's moduli and compressive strength increased, while Poisson's ratios and MPS decreased. All parameters were significantly correlated with the diameters of the filler particles (Pearson's correlation test, r = -0.949, 0.943, -0.951, 0.976, p < 0.05). The in silico multi-scale model established in this study demonstrates that the Young's moduli, Poisson's ratios, and compressive strengths of CAD/CAM CR blocks can be enhanced by loading silica nanofiller particles of smaller diameter. CAD/CAM CR blocks by using smaller silica nano-filler particles have a potential to increase fracture resistance.

Fillers for improved graphite fiber retention by polymer matrix composites

NASA Technical Reports Server (NTRS)

House, E. E.; Sheppard, C. H.

1981-01-01

The results of a program designed to determine the extent to which elemental boron and boron containing fillers added to the matrix resin of graphite/epoxy composites prevent the release of graphite fibers when the composites are exposed to fire and impact conditions are described. The fillers evaluated were boron, boron carbide and aluminum boride. The conditions evaluated were laboratory simulations of those that could exist in the event of an aircraft crash and burn situation. The baseline (i.e., unfilled) laminates evaluated were prepared from commercially available graphite/epoxy. The baseline and filled laminates' mechanical properties, before and after isothermal and humidity aging, also were compared. It was found that a small amount of graphite fiber was released from the baseline graphite/epoxy laminates during the burn and impact conditions used in this program. However, the extent to which the fibers were released is not considered a severe enough problem to preclude the use of graphite reinforced composites in civil aircraft structure. It also was found that the addition of boron and boron containing fillers to the resin matrix eliminated this fiber release. Mechanical properties of laminates containing the boron and boron containing fillers were lower than those of the baseline laminates. These property degradations for two systems: boron (5 micron) at 2.5 percent filler loading, and boron (5 micron) at 5.0 percent filler loading do not appear severe enough to preclude their use in structural composite applications.

Global Aesthetics Consensus: Avoidance and Management of Complications from Hyaluronic Acid Fillers—Evidence- and Opinion-Based Review and Consensus Recommendations

PubMed Central

Liew, Steven; Sundaram, Hema; De Boulle, Koenraad L.; Goodman, Greg J.; Monheit, Gary; Wu, Yan; Trindade de Almeida, Ada R.; Swift, Arthur; Vieira Braz, André

2016-01-01

Background: Although the safety profile of hyaluronic acid fillers is favorable, adverse reactions can occur. Clinicians and patients can benefit from ongoing guidance on adverse reactions to hyaluronic acid fillers and their management. Methods: A multinational, multidisciplinary group of experts in cosmetic medicine convened the Global Aesthetics Consensus Group to review the properties and clinical uses of Hylacross and Vycross hyaluronic acid products and develop updated consensus recommendations for early and late complications associated with hyaluronic acid fillers. Results: The consensus panel provided specific recommendations focusing on early and late complications of hyaluronic acid fillers and their management. The impact of patient-, product-, and technique-related factors on such reactions was described. Most of these were noted to be mild and transient. Serious adverse events are rare. Early adverse reactions to hyaluronic acid fillers include vascular infarction and compromise; inflammatory reactions; injection-related events; and inappropriate placement of filler material. Among late reactions are nodules, granulomas, and skin discoloration. Most adverse events can be avoided with proper planning and technique. Detailed understanding of facial anatomy, proper patient and product selection, and appropriate technique can further reduce the risks. Should adverse reactions occur, the clinician must be prepared and have tools available for effective treatment. Conclusions: Adverse reactions with hyaluronic acid fillers are uncommon. Clinicians should take steps to further reduce the risk and be prepared to treat any complications that arise. PMID:27219265

[Dental plaque microcosm biofilm behavior on a resin composite incorporated with nano-antibacterial inorganic filler containing long-chain alkyl quaternary ammonium salt].

PubMed

Junling, Wu; Qiang, Zhang; Ruinan, Sun; Ting, Zhu; Jianhua, Ge; Chuanjian, Zhou

2015-12-01

To develop a resin composite incorporated with nano-antibacterial inorganic filler containing long-chain alkyl quaternary ammonium salt, and to measure its effect on human dental plaque microcosm biofilm. A novel nano-antibacterial inorganic filler containing long-chain alkyl quaternary ammonium salt was synthesized according to methods introduced in previous research. Samples of the novel nano-antibacterial inorganic fillers were modified by a coupling agent and then added into resin composite at 0%, 5%, 10%, 15% or 20% mass fractions; 0% composite was used as control. A flexural test was used to measure resin composite mechanical properties. Results showed that a dental plaque microcosm biofilm model with human saliva as inoculum was formed. Colony-forming unit (CFU) counts, lactic acid production, and live/dead assay of biofilm on the resin composite were calculated to test the effect of the resin composite on human dental plaque microcosm biofilm. The incorporation of nano-antibacterial inorganic fillers with as much as 15% concentration into the resin composite showed no adverse effect on the mechanical properties of the resin composite (P > 0.05). Resin composite containing 5% or more nano-antibacterial inorganic fillers significantly inhibited the metabolic activity of dental plaque microcosm biofilm, suggesting its strong antibacterial potency (P < 0.05). This novel resin composite exhibited a strong antibacterial property upon the addition of up to 5% nano-antibacterial inorganic fillers, thereby leading to effective caries inhibition in dental application.

Effects of different surface modification and contents on municipal solid waste incineration fly ash/epoxy composites.

PubMed

Goh, C K; Valavan, S E; Low, T K; Tang, L H

2016-12-01

Incineration fly ash, a waste from municipal solid waste incineration plant can be used to replace conventional filler as reinforcing filler to enhance the mechanical strength of a composite. Surface modification was performed on the incineration fly ash before mixing into the soft polymer matrix so as to improve interfacial bond of the filler and epoxy resin. In this study, detailed characterisation of mechanical, morphological and leaching behaviours of municipal solid waste incineration (MSWI) fly ash infused composite has been carried out. Flexural and tensile test was conducted to determine the effect on mechanical properties of the composite by varying the concentration of incineration fly ash filler added into polymer matrix and surface modification of incineration fly ash filler using silane coupling agent and colloidal mesoporous silica (CMS). The results indicated that composite infused with incineration fly ash filler surface treated with CMS shown improvement on the tensile and flexural strengths. In addition, SEM images showed that surface modification of incineration fly ash with colloidal mesoporous silica enhanced the interfacial bonding with polymer resin which explained the improvement of mechanical strength. Leaching test showed result of toxic metals such as Pb, Zn, Fe, Cu, Cr, Cd and Rb immobilised in the polymer matrix of the composite. Hence, the use of MSWI fly ash as reinforcing filler in the composite appears green and sustainable because this approach is a promising opportunity to substitute valuable raw material with MSWI fly ash. Copyright © 2016 Elsevier Ltd. All rights reserved.

Mullins effect in a filled elastomer under uniaxial tension

DOE PAGES

Maiti, A.; Small, W.; Gee, R. H.; ...

2014-01-16

Modulus softening and permanent set in filled polymeric materials due to cyclic loading and unloading, commonly known as the Mullins effect, can have a significant impact on their use as support cushions. The quantitative analysis of such behavior is essential to ensure the effectiveness of such materials in long-term deployment. In this work we combine existing ideas of filler-induced modulus enhancement, strain amplification, and irreversible deformation within a simple non-Gaussian constitutive model to quantitatively interpret recent measurements on a relevant PDMS-based elastomeric cushion. Also, we find that the experimental stress-strain data is consistent with the picture that during stretching (loading)more » two effects take place simultaneously: (1) the physical constraints (entanglements) initially present in the polymer network get disentangled, thus leading to a gradual decrease in the effective cross-link density, and (2) the effective filler volume fraction gradually decreases with increasing strain due to the irreversible pulling out of an initially occluded volume of the soft polymer domain.« less

Free Volume Structure of Acrylic-Type Dental Nanocomposites Tested with Annihilating Positrons.

PubMed

Shpotyuk, Olha; Ingram, Adam; Shpotyuk, Oleh

2016-12-01

Positron annihilation spectroscopy in lifetime measuring mode exploring conventional fast-fast coincidence ORTEC system is employed to characterize free volume structure of commercially available acrylic-type dental restorative composite Charisma® (Heraeus Kulzer GmbH, Germany). The measured lifetime spectra for uncured and light-cured composites are reconstructed from unconstrained x3-term fitting and semi-empirical model exploring x3-x2-coupling decomposition algorithm. The governing channel of positron annihilation in the composites studied is ascribed to mixed positron-Ps trapping, where Ps decaying in the third component is caused entirely by input from free-volume holes in polymer matrix, while the second component is defined by free positron trapping in interfacial free-volume holes between filler nanoparticles and surrounded polymer matrix. Microstructure scenario of the photopolymerization shrinkage includes cross-linking of structural chains in polymer matrix followed by conversion of bound positron-electron (positronium) traps in positron-trapping interfacial free-volume voids in a vicinity of agglomerated filler nanoparticles.

Characterization of interaction between natural rubber and silica by FTIR

NASA Astrophysics Data System (ADS)

Jarnthong, Methakarn; Liao, Lusheng; Zhang, Fuquan; Wang, Yueqiong; Li, Puwang; Peng, Zheng; Malawet, Chutarat; Intharapat, Punyanich

2017-05-01

Blending of natural rubber (NR) and nanosilica (SiO2) was performed in latex state. The mechanical properties of NR/SiO2 nanocomposites at various filler contents were investigated. The interactions of unvulcanized natural rubber and nanosilica filler were characterized using Fourier Transform Infrared (FTIR)-Attenuated Total Reflectance (ATR) spectroscopy. The relationship between mechanical properties and rubber-filler interaction was discussed.

Nanostructured conductive polymeric materials

NASA Astrophysics Data System (ADS)

Al-Saleh, Mohammed H.

Conductive polymer composites (CPCs) are a suitable alternative to metals in many applications due to their light-weight, corrosion resistance, low cost, ease of processing and design flexibility. CPCs have been formulated using different types of conductive fillers. In this PhD thesis, the focus is on CPCs for electrostatic discharge (ESD) protection and electromagnetic interference (EMI) attenuation. Despite the versatility of conductive fillers, carbon black (CB) has been the dominant filler to make CPCs for ESD protection applications because CB/polymer composites have a cost advantage over all other CPCs. For EMI shielding, stainless steel fibres and metal coated fibers are the preferred fillers, however CPCs made of those fibers are not the dominant EMI shielding materials. Metal coated and polymer plated polymers are the most widely used EMI shielding options. The limited use of CPCs in the EMI shielding market is because the high filler loading required to formulate a composite with an adequate level of shielding remarkably increases the composite price. In order to increase the competitiveness of CPCs, percolation threshold should be minimized as much as possible and composites with high EMI shielding capabilities at low filler loading should be formulated because all conductive fillers are expensive compared to polymers. In this thesis, two different methodologies to reduce percolation threshold in CPCs have been successfully developed and a CPC with exceptional EMI shielding capability has been formulated using copper nanowires as conductive filler. The first percolation threshold reduction technique is based on the selective localization of CB at the interface of immiscible polymer blend. The technique requires adding a copolymer that prefers the blend's interface and for which CB nanoparticles has the highest affinity. The second method is based on producing a CPC powder and then using this powder as a conductive filler to produce composite by dry mixing with pure polymer powder followed by compression molding. The EMI shielding material was developed using copper nanowires. CuNW/Polystyrene composites exhibit EMI shielding effectiveness exceeding that of metal microfillers and carbon nanotube/polymer composites and approaching that of coating techniques have been formulated by solution processing and dry mixing.

Structural and functional polymer-matrix composites for electromagnetic applications

NASA Astrophysics Data System (ADS)

Wu, Junhua

This dissertation addresses the science and technology of functional and structural polymer-matrix composite materials for electromagnetic applications, which include electromagnetic interference (EMI) shielding and low observability (Stealth). The structural composites are continuous carbon fiber epoxy-matrix composites, which are widely used for airframes. The functional composites are composites with discontinuous fillers and in both bulk and coating forms. Through composite structure variation, attractive electromagnetic properties have been achieved. With no degradation of the tensile strength or modulus, the shielding effectiveness of the structural composites has been improved by enhancing multiple reflections through light activation of the carbon fiber. The multiple reflections loss of the electromagnetic wave increases from 1.1 to 10.2 dB at 1.0 GHz due to the activation. Such a large effect of multiple reflections has not been previously reported in any material. The observability of these composites has been lowered by decreasing the electrical conductivity (and hence decreasing the reflection loss) through carbon fiber coating. The incorporation of mumetal, a magnetic alloy particulate filler (28-40 mum size), in a latex paint has been found to be effective for enhancing the shielding only if the electrical resistivity of the resulting composite coating is below 10 O.cm, as rendered by a conductive particulate filler, such as nickel flake (14-20 mum size). This effectiveness (39 dB at 1.0 GHz) is attributed to the absorption of the electromagnetic wave by the mumetal and the nickel flake, with the high conductivity rendered by the presence of the nickel flake resulting in a relatively high reflection loss of 15.5 dB. Without the nickel flake, the mumetal gives only 3 dB of shielding and 1.5 dB of reflection loss at 1.0 GHz. Nickel powder (0.3-0.5 mum size) has been found to be an effective filler for improving the shielding of polyethersulfone (PES) bulk composites. At 13 vol.%, it gives 90 dB of shielding at 1.0 GHz, compared to 46 dB for nickel powder (20-40 mum) and the prior value of 87 dB reported by Shui and Chung for nickel filament (0.4 mum diameter). The minimum filler content for high shielding is 7-13 vol.% for both nickel powders, compared to 3-7 vol.% for nickel filament. Due to the skin effect, a small filler unit size helps the shielding, which is dominated by reflection. Carbon filament (0.1 mum, >100 mum long, >1000 in aspect ratio) is effective for enhancing the shielding effectiveness of a coating made from a water-based colloid that contains graphite particle (0.7-0.8 mum, 22 wt.%) and a starch-type binder. The filament addition increases the shielding from 11 to 20 dB at 1.0 GHz. This increase in shielding is associated with increase in reflectivity and decrease in electrical resistivity. Graphite flake (5 mum) at the same volume proportion is even more effective; its addition increases the shielding from 11 to 28 dB. The combined use of the graphite flake and a low proportion of stainless steel fiber (11 mum diameter, 2 mm long, 180 in aspect ratio) is yet more effective; it increases the shielding from 11 to 34 dB. Alumina particle (5 mum size, 15 vol.%) is effective for increasing the impedance of a coating made from the graphite colloid by 290%, though the shielding effectiveness is reduced from 18 to 11 dB at 1.0 GHz. The high impedance is attractive for MRIcompatible pacemaker leads. The interface between filler and matrix also affects the shielding. Silane treatment of the surface of graphite flake (5 mum) used in the graphite colloid decreases the viscosity (e.g., from 1750 to 1460 CP), but it also decreases the shielding effectiveness (e.g., from 20 to 16 dB at 1 GHz). Ozone treatment gives a similar effect. The decrease of the shielding effectiveness is attributed to the increase in resistivity due to the surface treatment. Measured and calculated values of the reflection loss are comparable, with the measured value lower than the corresponding calculated value, when the resistivity is sufficiently low (e.g., resistivity below 10 O.cm in case of PES-matrix composites) and a strongly magnetic filler such as mumetal is absent. The agreement is better when the skin depth approaches the specimen thickness. The agreement is worse for the latex paint-based composites than the PES-matrix composites, probably due to superior electrical connectivity in the latter.

Effect of blue and violet light on polymerization shrinkage vectors of a CQ/TPO-containing composite.

PubMed

Sampaio, Camila S; Atria, Pablo J; Rueggeberg, Frederick A; Yamaguchi, Satoshi; Giannini, Marcelo; Coelho, Paulo G; Hirata, Ronaldo; Puppin-Rontani, Regina M

2017-07-01

To evaluate the effect of light-curing wavelengths on composite filler particle displacement, and thus to visualize localized polymerization shrinkage in a resin-based composite (RBC) containing camphorquinone (CQ) and Lucirin TPO (TPO). Three light-curing units (LCUs) were used to light-cure a RBC containing CQ and TPO: a violet-only, a blue-only, and a dual-wavelength, conventional (Polywave ® , emitting violet and blue wavelengths simultaneously). Zirconia fillers were added to the RBC to act as filler particle displacement tracers. LCUs were characterized for total emitted power (mW) and spectral irradiant output (mW/cm 2 /nm). 2-mm high, 7-mm diameter silanized glass cylindrical specimens were filled in a single increment with the RBC, and micro-computed tomography (μ-CT) scans were obtained before and after light-curing, according to each LCU (n=6). Filler particle movement identified polymerization shrinkage vectors, traced using software, at five depths (from 0 up to 2mm): top, top-middle, middle, middle-bottom and bottom. Considering different RBC depths within the same LCU, use of violet-only and conventional LCUs showed filler particle movement decreased with increased depth. Blue-only LCU showed homogeneous filler particle movement along the depths. Considering the effect of different LCUs within the same depth, filler particle movement within LCUs was not statistically different until the middle of the samples (P>.05). However, at the middle-bottom and bottom depths (1.5 and 2mm, respectively), blue-only LCU compared to violet-only LCU showed higher magnitude of displacement vector values (P<.05). Use of the conventional LCU showed filler displacement magnitudes that were not significantly different than blue-only and violet-only LCUs at any depth (P>.05). With respect to the direction of particle movement vectors, use of violet-only LCU showed a greater displacement when close to the incident violet LED; blue-only LCU showed equally distributed particle displacement values within entire depth among the samples; and the conventional LCU showed greater filler displacement closer to the blue LED locations. Filler particle displacement in a RBC as a result of light-curing is related to localized application of light wavelength and total emitted power of the light emitted on the top surface of the RBC. When the violet LED is present (violet-only and conventional LCUs), filler particle displacement magnitude decreased with increased depth, while results using the blue-only LED show a more consistent pattern of displacement. Clinically, these results correlate to production of different characteristics of curing within a RBC restoration mass, depending on localized wavelengths applied to the irradiated surface. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

New Manufacturing Method for Paper Filler and Fiber Material

DOE Office of Scientific and Technical Information (OSTI.GOV)

Doelle, Klaus

2013-08-25

The use of fillers in printing and writing papers has become a prerequisite for competing in a global market to reduce the cost of materials. Use of calcium carbonates (ranging from 18% to 30%) as filler is a common practice in the paper industry but the choices of fillers for each type of papers vary widely according to its use. The market for uncoated digital printing paper is one that continues to introduce exciting growth projections. and it is important to understand the effect that new manufacturing methods of calcium carbonates have on the energy efficiency and paper production. Research conducted under this award showed that the new fiber filler composite material has the potential to increase the paper filler content by up to 5% without losing mechanical properties. Benefits of the technology can be summarized as follows for a 1% filler increase per metric ton of paper produced: (i) production cost savings overmore » $$12, (ii) Energy savings of 100,900 btu, (iii) CO{sub 2} emission savings of 33 lbs, and additional savings for wood preparation, pulping, recovery of 203593 btu with a 46lbs of CO{sub 2} emission savings per 1% filler increase. In addition the technology has the potential to save: (i) additional $$3 per ton of bleached pulp produced, (ii) bleaching energy savings of 170,000 btu, (iii) bleaching CO{sub 2} emission savings of 39 lbs, and (iv) additional savings for replacing conventional bleaching chemicals with a sustainable bleaching chemical is estimated to be 900,000 btu with a 205 lbs of CO{sub 2} emission savings per ton of bleached pulp produced. All the above translates to a estimated annual savings for a 12% filler increase of 296 trillion buts or 51 million barrel of oil equivalent (BOE) or 13.7% of the industries energy demand. This can lead to a increase of renewable energy usage from 56% to close to 70% for the industry sector. CO{sub 2} emission of the industry at a 12% filler increase could be lowered by over 39 million tons annually. If the new technology could be implemented for bleaching process a total annual estimated energy savings potential of 64 trillion buts or 11 million barrel of oil equivalent (BOE) equal to 3% of the paper industries energy demand could be realized. This could lead to a increase of renewable energy usage from 56% to close to 60% for the industry. CO{sub 2} emissions could be lowered by over 7.4 million tons annually. It is estimated that an installed system could also yield a 75 to 100% return of investment (ROI) rate for the capital equipment that need to be installed for the fiber filler composite manufacturing process.« less

Polyurethane foam with multi walled carbon nanotubes/magnesium hybrid filler

NASA Astrophysics Data System (ADS)

Adnan, Sinar Arzuria; Zainuddin, Firuz; Zaidi, Nur Hidayah Ahmad; Akil, Hazizan Md.; Ahmad, Sahrim

2016-07-01

The purpose of this paper is to investigate the effect of multiwalled carbon nanotubes (MWCNTs)/magnesium (Mg) hybrid filler in polyurethane (PU) foams with different weight percentages (0.5 wt.% to 3.0 wt.%). The PU/MWCNTs/Mg foam composites were formed by reaction of based palm oil polyol (POP) with methylene diphenyl diisocyanate (MDI) with ratio 1:1.1 by weight. The foam properties were evaluated in density, morphology and compressive strength. The addition of 2.5 wt.% hybrid filler showed the higher density in 59.72 kg/m3 and thus contribute to the highest compressive strength at 1.76 MPa. The morphology show cell in closed structure and addition hybrid filler showed uneven structure.

Thermal properties and dynamic mechanical properties of ceramic fillers filled epoxy composites

NASA Astrophysics Data System (ADS)

Saidina, D. S.; Mariatti, M.; Juliewatty, J.

2015-07-01

This present study is aimed to enhance the thermal and dynamic mechanical properties of ceramic fillers such as Calcium Copper Titanate, CaCu3Ti4O12 (CCTO) and Barium Titanate (BaTiO3) filled epoxy thin film composites. As can be seen from the results, 20 vol% BaTiO3/epoxy thin film composite showed the lowest coefficient of thermal expansion (CTE) value, the highest decomposition temperature (T5 and Tonset) and weight of residue among the composites as the filler has low CTE value, distributed homogeneously throughout the composite and less voids can be seen between epoxy resin and BaTiO3 filler.

Effect of Filler Concentration on Thermal Stability of Vinyl Copolymer Elastomer (VCE) Composites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Dali; Hubbard, Kevin Mark; Devlin, David James

To study the thermal stability of vinyl copolymer elastomer (VCE) in its composite form, systematic TGA characterizations were conducted in both nonisothermal and isothermal modes. The effects of filler concentration on the aging behaviors of the VCE/filler composites were investigated under nitroplasticizer (NP) environment. FTIR characterization was used to probe the structural changes in the VCE polymer before and after the thermal treatments. This study suggests that the filler concentration significantly deteriorates the thermal stability of NP at a moderate temperature (< 70 °C). The degradation of NP, in turn, accelerates the aging process of the VCE polymer in itsmore » composite form.« less

How To Be Stupid: The Teachings of Channel One.

ERIC Educational Resources Information Center

Miller, Mark Crispin

The news on Channel One, with its impression of vague anxiety, looks and sounds like regular television news, only more so. In either case, the news is just "filler"--its real function is not journalistic but commercial, meant to lead into advertisements (ads). Mass advertising tends to assume that its audience will not be studying it…

"Et Pis Bon, Ben Alors Voilà Quoi!" Teaching Those Pesky Discourse Markers

ERIC Educational Resources Information Center

Mullan, Kerry

2016-01-01

Discourse markers have been described as "nervous tics, fillers, or signs of hesitation", and are frequently dismissed as features of lazy or inarticulate speech. Yet in fact they have a number of crucial functions in spoken interaction, such as buying time, managing turn taking, linking utterances, introducing a new topic and indicating…

Effect of filler loading and silane modification on the biodegradability of SBR composites reinforced with peanut shell powder

NASA Astrophysics Data System (ADS)

Shaniba, V.; Balan, Aparna K.; Sreejith, M. P.; Jinitha, T. V.; Subair, N.; Purushothaman, E.

2017-06-01

The development of biocomposites and their applications are important in material science due to environmental and sustainability issues. The extent of degradation depends on the nature of reinforcing filler, particle size and their modification. In this article, we tried to focus on the biodegradation of composites of Styrene Butadiene Rubber (SBR) reinforced with Peanut Shell Powder (PSP) by soil burial test. The composites of SBR with untreated PSP (UPSP) and silane modified PSP (SPSP) of 10 parts per hundred rubber (phr) and 20 phr filler loading in two particle size were buried in the garden soil for six months. The microbial degradation were assessed through the measurement of weight loss, tensile strength and hardness at definite period. The study shows that degradation increases with increase in filler loading and particle size. The chemical treatment of filler has been found to resist the degradation. The analysis of morphological properties by the SEM also confirmed biodegradation process by the microorganism in the soil.

Improved microstructure and mechanical properties in gas tungsten arc welded aluminum joints by using graphene nanosheets/aluminum composite filler wires.

PubMed

Fattahi, M; Gholami, A R; Eynalvandpour, A; Ahmadi, E; Fattahi, Y; Akhavan, S

2014-09-01

In the present study, different amounts of graphene nanosheets (GNSs) were added to the 4043 aluminum alloy powders by using the mechanical alloying method to produce the composite filler wires. With each of the produced composite filler wires, one all-weld metal coupon was welded using the gas tungsten arc (GTA) welding process. The microstructure, mechanical properties and fracture surface morphology of the weld metals have been evaluated and the results are compared. As the amount of GNSs in the composition of filler wire is increased, the microstructure of weld metal was changed from the dendritic structure to fine equiaxed grains. Furthermore, the tensile strength and microhardness of weld metal was improved, and is attributed to the augmented nucleation and retarded growth. From the results, it was seen that the GNSs/Al composite filler wire can be used to improve the microstructure and mechanical properties of GTA weld metals of aluminum and its alloys. Copyright © 2014 Elsevier Ltd. All rights reserved.

Enhancement of Fracture Toughness of Epoxy Nanocomposites by Combining Nanotubes and Nanosheets as Fillers

PubMed Central

Domun, Nadiim; Paton, Keith R.; Sainsbury, Toby; Zhang, Tao; Mohamud, Hibaaq

2017-01-01

In this work the fracture toughness of epoxy resin has been improved through the addition of low loading of single part and hybrid nanofiller materials. Functionalised multi-walled carbon nanotubes (f-MWCNTs) was used as single filler, increased the critical strain energy release rate, GIC, by 57% compared to the neat epoxy, at only 0.1 wt% filler content. Importantly, no degradation in the tensile or thermal properties of the nanocomposite was observed compared to the neat epoxy. When two-dimensional boron nitride nanosheets (BNNS) were added along with the one-dimensional f-MWCNTs, the fracture toughness increased further to 71.6% higher than that of the neat epoxy. Interestingly, when functionalised graphene nanoplatelets (f-GNPs) and boron nitride nanotubes (BNNTs) were used as hybrid filler, the fracture toughness of neat epoxy is improved by 91.9%. In neither of these hybrid filler systems the tensile properties were degraded, but the thermal properties of the nanocomposites containing boron nitride materials deteriorated slightly. PMID:29048345

Application of waste bulk moulded composite (BMC) as a filler for isotactic polypropylene composites.

PubMed

Barczewski, Mateusz; Matykiewicz, Danuta; Andrzejewski, Jacek; Skórczewska, Katarzyna

2016-05-01

The aim of this study was to produce isotactic polypropylene based composites filled with waste thermosetting bulk moulded composite (BMC). The influence of BMC waste addition (5, 10, 20 wt%) on composites structure and properties was investigated. Moreover, additional studies of chemical treatment of the filler were prepared. Modification of BMC waste by calcium stearate (CaSt) powder allows to assess the possibility of the production of composites with better dispersion of the filler and more uniform properties. The mechanical, processing, and thermal properties, as well as structural investigations were examined by means of static tensile test, Dynstat impact strength test, differential scanning calorimetry (DSC), wide angle X-ray scattering (WAXS), melt flow index (MFI) and scanning electron microscopy (SEM). Developed composites with different amounts of non-reactive filler exhibited satisfactory thermal and mechanical properties. Moreover, application of the low cost modifier (CaSt) allows to obtain composites with better dispersion of the filler and improved processability.

Electro-mechanical properties of hydrogel composites with micro- and nano-cellulose fillers

NASA Astrophysics Data System (ADS)

N, Mohamed Shahid U.; Deshpande, Abhijit P.; Lakshmana Rao, C.

2015-09-01

Stimuli responsive cross-linked hydrogels are of great interest for applications in diverse fields such as sensors and biomaterials. In this study, we investigate polymer composites filled with cellulose fillers. The celluloses used in making the composites were a microcrystalline cellulose of commercial grade and cellulose nano-whiskers obtained through acid hydrolysis of microcrystalline cellulose. The filler concentration was varied and corresponding physical, mechanical and electro-mechanical characterization was carried out. The electro-mechanical properties were determined using a quasi-static method. The fillers not only enhance the mechanical properties of the composite by providing better reinforcement but also provide a quantitative electric potential in the composite. The measurements reveal that the polymer composites prepared from two different cellulose fillers possess a quantitative electric potential which can be utilized in biomedical applications. It is argued that the mechanism behind the quantitative electric potential in the composites is due to streaming potentials arising due to electrical double layer formation.

Directionally solidified article with weld repair

NASA Technical Reports Server (NTRS)

Smashey, Russell W. (Inventor); Snyder, John H. (Inventor); Borne, Bruce L. (Inventor)

2003-01-01

A directionally solidified nickel-base superalloy article has a defect therein extending parallel to the solidification direction. The article is repaired by removing any foreign matter present in the defect, and then heating the article to a repair temperature of from about 60 to about 98 percent of the solidus temperature of the base material in a chamber containing a protective gas that inhibits oxidation of the base material. The defect is filled with a filler metal while maintaining the article at the repair temperature. The filling is accomplished by providing a source of the filler metal of substantially the same composition as the base material of the directionally solidified article, and melting the filler metal into the defect progressively while moving the source of the filler metal relative to the article in a direction parallel to the solidification direction. Optionally, additional artificial heat extraction is accomplished in a heat-flow direction that is within about 45 degrees of the solidification direction, as the filler metal solidifies within the defect. The article may thereafter be heat treated.

Weld repair of directionally solidified articles

NASA Technical Reports Server (NTRS)

Smashey, Russell W. (Inventor); Snyder, John H. (Inventor); Borne, Bruce L. (Inventor)

2002-01-01

A directionally solidified nickel-base superalloy article has a defect therein extending parallel to the solidification direction. The article is repaired by removing any foreign matter present in the defect, and then heating the article to a repair temperature of from about 60 to about 98 percent of the solidus temperature of the base material in a chamber containing a protective gas that inhibits oxidation of the base material. The defect is filled with a filler metal while maintaining the article at the repair temperature. The filling is accomplished by providing a source of the filler metal of substantially the same composition as the base material of the directionally solidified article, and melting the filler metal into the defect progressively while moving the source of the filler metal relative to the article in a direction parallel to the solidification direction. Optionally, additional artificial heat extraction is accomplished in a heat-flow direction that is within about 45 degrees of the solidification direction, as the filler metal solidifies within the defect. The article may thereafter be heat treated.

Application of waste bulk moulded composite (BMC) as a filler for isotactic polypropylene composites

PubMed Central

Barczewski, Mateusz; Matykiewicz, Danuta; Andrzejewski, Jacek; Skórczewska, Katarzyna

2016-01-01

The aim of this study was to produce isotactic polypropylene based composites filled with waste thermosetting bulk moulded composite (BMC). The influence of BMC waste addition (5, 10, 20 wt%) on composites structure and properties was investigated. Moreover, additional studies of chemical treatment of the filler were prepared. Modification of BMC waste by calcium stearate (CaSt) powder allows to assess the possibility of the production of composites with better dispersion of the filler and more uniform properties. The mechanical, processing, and thermal properties, as well as structural investigations were examined by means of static tensile test, Dynstat impact strength test, differential scanning calorimetry (DSC), wide angle X-ray scattering (WAXS), melt flow index (MFI) and scanning electron microscopy (SEM). Developed composites with different amounts of non-reactive filler exhibited satisfactory thermal and mechanical properties. Moreover, application of the low cost modifier (CaSt) allows to obtain composites with better dispersion of the filler and improved processability. PMID:27222742

Enhancement of Fracture Toughness of Epoxy Nanocomposites by Combining Nanotubes and Nanosheets as Fillers.

PubMed

Domun, Nadiim; Paton, Keith R; Hadavinia, Homayoun; Sainsbury, Toby; Zhang, Tao; Mohamud, Hibaaq

2017-10-19

In this work the fracture toughness of epoxy resin has been improved through the addition of low loading of single part and hybrid nanofiller materials. Functionalised multi-walled carbon nanotubes (f-MWCNTs) was used as single filler, increased the critical strain energy release rate, G IC , by 57% compared to the neat epoxy, at only 0.1 wt% filler content. Importantly, no degradation in the tensile or thermal properties of the nanocomposite was observed compared to the neat epoxy. When two-dimensional boron nitride nanosheets (BNNS) were added along with the one-dimensional f-MWCNTs, the fracture toughness increased further to 71.6% higher than that of the neat epoxy. Interestingly, when functionalised graphene nanoplatelets (f-GNPs) and boron nitride nanotubes (BNNTs) were used as hybrid filler, the fracture toughness of neat epoxy is improved by 91.9%. In neither of these hybrid filler systems the tensile properties were degraded, but the thermal properties of the nanocomposites containing boron nitride materials deteriorated slightly.

The partial replacement of palm kernel shell by carbon black and halloysite nanotubes as fillers in natural rubber composites

NASA Astrophysics Data System (ADS)

Daud, Shuhairiah; Ismail, Hanafi; Bakar, Azhar Abu

2017-07-01

The effect of partial replacement of palm kernel shell powder by carbon black (CB) and halloysite nanotube (HNT) on the tensile properties, rubber-filler interaction, thermal properties and morphological studies of natural rubber (NR) composites were investigated. Four different compositions of NR/PKS/CB and NR/PKS/HNT composites i.e 20/0, 15/5, 10/10,5/15 and 0/20 parts per hundred rubber (phr) were prepared on a two roll mill. The results showed that the tensile strength and modulus at 100% elongation (M100) and 300% elongation (M300) were higher for NR/PKS/CB compared to NR/PKS/HNT composites. NR/PKS/CB composites had the lowest elongation at break (Eb). The effect of commercial fillers in NR/PKS composites on tensile properties was confirmed by the rubber-filler interaction and scanning electron microscopy (SEM) study. The thermal stability of PKS filled NR composites with partially replaced by commercial fillers also determined by Thermo gravimetric Analysis (TGA).

A new technique for the strengthening of aluminum tungsten inert gas weld metals: using carbon nanotube/aluminum composite as a filler metal.

PubMed

Fattahi, M; Nabhani, N; Rashidkhani, E; Fattahi, Y; Akhavan, S; Arabian, N

2013-01-01

The effect of multi-walled carbon nanotube (MWCNT) on the mechanical properties of aluminum multipass weld metal prepared by the tungsten inert gas (TIG) welding process was investigated. High energy ball milling was used to disperse MWCNT in the aluminum powder. Carbon nanotube/aluminum composite filler metal was fabricated for the first time by hot extrusion of ball-milled powders. After welding, the tensile strength, microhardness and MWCNT distribution in the weld metal were investigated. The test results showed that the tensile strength and microhardness of weld metal was greatly increased when using the filler metal containing 1.5 wt.% MWCNT. Therefore, according to the results presented in this paper, it can be concluded that the filler metal containing MWCNT can serve as a super filler metal to improve the mechanical properties of TIG welds of Al and its alloys. Copyright © 2013 Elsevier Ltd. All rights reserved.

Raman Spectroscopy of Novel UHMW Polyethylene-Based Nanocomposites with Nanographite and Nanoclay

NASA Astrophysics Data System (ADS)

Prokhorov, K. A.; Sagitova, E. A.; Averin, A. A.; Nikolaeva, G. Yu; Baimova, A. V.; Novokshonova, L. A.; Brevnov, P. N.; Pashinin, P. P.

2018-04-01

We analyze the Raman spectra of nanocomposites based on ultrahigh-molecular-weight polyethylene with nanoclay, thermoexpanded graphite, and reduced graphite oxide fillers. We discuss the potential of Raman spectroscopy for quantitative analysis of the nanocomposite structure, the influence of the fillers on the phase and conformation compositions of the polymer matrix, as well as for the monitoring of dispersion of the nanographite fillers in the nanocomposites.

Fillers: from the past to the future.

PubMed

Glogau, Richard G

2012-06-01

Modern medical use of injectable soft-tissue augmentation fillers has evolved from the introduction of bovine collage implants to an array of synthesized materials in the current domestic and foreign markets. The concept of augmentation has moved from simple lines, scars, and wrinkles to revolumizing the aging face. A brief overview of the past, present, and future injectable fillers is presented. Copyright © 2012 Elsevier Inc. All rights reserved.

Co-spray Drying with HPMC as a Platform to Improve Direct Compaction Properties of Various Tablet Fillers.

PubMed

Li, JinZhi; Zhao, LiJie; Lin, Xiao; Shen, Lan; Feng, Yi

2017-11-01

Many commonly used tablet fillers are not suitable for direct compaction process due to insufficient properties, mainly of flowability and compactability. This work therefore aimed to use co-spray drying with HPMC as a platform to improve direct compaction properties of various tablet fillers. Starch, calcium hydrogen phosphate dihydrate (DCPD), and mannitol were chosen as a representative of three types of commonly used fillers (i.e. organic macromolecules, water-insoluble inorganic salts, and water-soluble small molecular carbohydrates), respectively. The five-level central composite design-response surface methodology was used (i) to investigate the effects of HPMC level and solid content of the feed on various powder, tableting, and tablet properties of composite excipients, and (ii) to optimize the composition. The results showed that the impacts of the two factors on various properties of composite excipients showed great similarity, despite of significantly different primary properties of the parent fillers, and the HPMC level was the main contributor to the majority of the impacts. An increase in HPMC level significantly improved tablet tensile strength and various tableting parameters. For all the three fillers, their optimized composite excipients provided by the established models showed excellent performances as predicted. The platform suggested is confirmed to be effective and promising.

Use of Almond Shells and Rice Husk as Fillers of Poly(Methyl Methacrylate) (PMMA) Composites.

PubMed

Sabbatini, Alessandra; Lanari, Silvia; Santulli, Carlo; Pettinari, Claudio

2017-07-28

In recent years, wood fibres have often been applied as the reinforcement of thermoplastic materials, such as polypropylene, whereas their use in combination with thermosetting resin has been less widespread. This study concerns the production of PMMA-based composites by partly replacing alumina trihydrate (ATH) with wood waste fillers, namely rice husks and almond shells, which would otherwise be disposed by incineration. The amount of filler introduced was limited to 10% as regards rice husks and 10 or 15% almond shells, since indications provided by reactivity tests and viscosity measurements did not suggest the feasibility of total replacement of ATH. As a matter of fact, the introduction of these contents of wood waste filler in PMMA-based composite did not result in any significant deterioration of its mechanical properties (Charpy impact, Rockwell M hardness and flexural performance). Some reduction of these properties was only observed in the case of introduction of 15% almond shells. A further issue concerned the yellowing of the organic filler under exposure to UV light. On the other hand, a very limited amount of water was absorbed, never exceeding values around 0.6%, despite the significant porosity revealed by the filler's microscopic evaluation. These results are particularly interesting in view of the application envisaged for these composites, i.e., wood replacement boards.

Reaction layer characterization of the braze joint of silicon nitride to stainless steel

NASA Astrophysics Data System (ADS)

Xu, R.; Indacochea, J. E.

1994-10-01

This investigation studies the role of titanium in the development of the reaction layer in braze joining silicon nitride to stainless steel using titanium-active copper-silver filler metals. This reaction layer formed as a result of titanium diffusing to the filler metal/silicon nitride interface and reacting with the silicon nitride to form the intermetallics, titanium nitride (TiN) and titanium suicide (Ti 5Si3). This reaction layer, as recognized in the literature, allows wetting of the ceramic substrate by the molten filler metal. The reaction layer thickness increases with temperature and time. Its growth rate obeys the parabolic relationship. Activation energies of 220.1 and 210.9 kj/mol were calculated for growth of the reaction layer for the two filler metals used. These values are close to the activation energy of nitrogen in TiN (217.6 kj/mol). Two filler metals were used in this study, Ticusil (68.8 wt% Ag, 26.7 wt% Cu, 4.5 wt% Ti) and CB4 (70.5 wt% Ag, 26.5 wt% Cu, 3.0 wt% Ti). The joints were processed in vacuum at temperatures of 840 to 900 °C at various times. Bonding strength is affected by reaction layer thickness in the absence of Ti-Cu intermetallics in the filler metal matrix.

Nanoparticle amount, and not size, determines chain alignment and nonlinear hardening in polymer nanocomposites

PubMed Central

Varol, H. Samet; Meng, Fanlong; Hosseinkhani, Babak; Malm, Christian; Bonn, Daniel; Bonn, Mischa; Zaccone, Alessio

2017-01-01

Polymer nanocomposites—materials in which a polymer matrix is blended with nanoparticles (or fillers)—strengthen under sufficiently large strains. Such strain hardening is critical to their function, especially for materials that bear large cyclic loads such as car tires or bearing sealants. Although the reinforcement (i.e., the increase in the linear elasticity) by the addition of filler particles is phenomenologically understood, considerably less is known about strain hardening (the nonlinear elasticity). Here, we elucidate the molecular origin of strain hardening using uniaxial tensile loading, microspectroscopy of polymer chain alignment, and theory. The strain-hardening behavior and chain alignment are found to depend on the volume fraction, but not on the size of nanofillers. This contrasts with reinforcement, which depends on both volume fraction and size of nanofillers, potentially allowing linear and nonlinear elasticity of nanocomposites to be tuned independently. PMID:28377517

Thermally Conductive-Silicone Composites with Thermally Reversible Cross-links.

PubMed

Wertz, J T; Kuczynski, J P; Boday, D J

2016-06-08

Thermally conductive-silicone composites that contain thermally reversible cross-links were prepared by blending diene- and dienophile-functionalized polydimethylsiloxane (PDMS) with an aluminum oxide conductive filler. This class of thermally conductive-silicones are useful as thermal interface materials (TIMs) within Information Technology (IT) hardware applications to allow rework of valuable components. The composites were rendered reworkable via retro Diels-Alder cross-links when temperatures were elevated above 130 °C and required little mechanical force to remove, making them advantageous over other TIM materials. Results show high thermal conductivity (0.4 W/m·K) at low filler loadings (45 wt %) compared to other TIM solutions (>45 wt %). Additionally, the adhesion of the material was found to be ∼7 times greater at lower temperatures (25 °C) and ∼2 times greater at higher temperatures (120 °C) than commercially available TIMs.

Feasibility of using microencapsulated phase change materials as filler for improving low temperature performance of rubber sealing materials.

PubMed

Tiwari, Avinash; Shubin, Sergey N; Alcock, Ben; Freidin, Alexander B; Thorkildsen, Brede; Echtermeyer, Andreas T

2017-11-01

The feasibility of a novel composite rubber sealing material to improve sealing under transient cooling (in a so-called blowdown scenario) is investigated here. A composite of hydrogenated nitrile butadiene rubber (HNBR) filled with Micro Encapsulated Phase Change Materials (MEPCM) is described. The fillers contain phase change materials that release heat during the phase transformation from liquid to solid while cooling. This exotherm locally heats the rubber and may improve the function of the seal during a blowdown event. A representative HNBR-MEPCM composite was made and the critical thermal and mechanical properties were obtained by simulating the temperature distribution during a blowdown event. Simulations predict that the MEPCM composites can delay the temperature decrease in a region of the seal during the transient blowdown. A sensitivity analysis of material properties is also presented which highlights possible avenues of improvement of the MEPCMs for sealing applications.

Highly aging-resistant elastomers doped with antioxidant-loaded clay nanotubes.

PubMed

Fu, Ye; Zhao, Detao; Yao, Pengjun; Wang, Wencai; Zhang, Liqun; Lvov, Yuri

2015-04-22

A novel aging-resistant styrene-butadiene rubber (SBR) composite is prepared using the antioxidant N-isopropyl-N'-phenyl-p-phenylenediamine (4010NA) loaded inside of halloysite clay nanotubes and used as filler. Loading the antioxidant inside of halloysite allows for its sustained release for nine months in the rubber matrix. By utilizing modified halloysite, the antioxidant concentration in this rubber nanoformulation is tripled without causing "blooming" defects. Furthermore, the halloysite is silanized to enhance its miscibility with rubber. The aging resistance of SBR-halloysite composites is studied by comparing the mechanical properties before and after thermal-oxidative aging. A seven-day test at 90 °C shows preservation of mechanical properties, and no 4010NA blooming is observed, even after one month. Styrene-butadiene rubber with 27 wt % halloysite loaded with 4010NA shows marked increase in aging resistance and promising future of halloysite as a functional rubber filler.

Inhibitory effect of resin composite containing S-PRG filler on Streptococcus mutans glucose metabolism.

PubMed

Kitagawa, Haruaki; Miki-Oka, Saeki; Mayanagi, Gen; Abiko, Yuki; Takahashi, Nobuhiro; Imazato, Satoshi

2018-03-01

Resin composites containing surface pre-reacted glass-ionomer (S-PRG) fillers have been reported to inhibit Streptococcus mutans growth on their surfaces, and their inhibitory effects were attributed to BO 3 3- and F - ions. The aim of this study was to evaluate S. mutans acid production through glucose metabolism on resin composite containing S-PRG fillers and assess inhibitory effects of BO 3 3- and F - on S. mutans metabolic activities. The pH change through S. mutans acid production on experimental resin composite was periodically measured after the addition of glucose. Inhibitory effects of BO 3 3- or F - solutions on S. mutans metabolism were evaluated by XTT assays and measurement of the acid production rate. The pH of experimental resin containing S-PRG fillers was significantly higher than that of control resin containing silica fillers (p < 0.05). OD 450 values by XTT assays and S. mutans acid production rates significantly decreased in the presence of BO 3 3- and F - compared with the absence of these ions (p < 0.05). pH reduction by S. mutans acid production was inhibited on resin composite containing S-PRG fillers. Moreover, S. mutans glucose metabolism and acid production were inhibited in the presence of low concentrations of BO 3 3- or F - . BO 3 3- or F - released from resin composite containing S-PRG fillers exhibits inhibitory effects on S. mutans metabolism at concentrations lower than those which inhibit bacterial growth. Copyright © 2017 Elsevier Ltd. All rights reserved.

Optimizing outcomes with polymethylmethacrylate fillers.

PubMed

Gold, Michael H; Sadick, Neil S

2018-06-01

The ideal filler should be long-lasting, biocompatible, chemically inert, soft and easy to use, and have a long history of safety. This review focuses on the evolution and development of the PMMA-collagen gel, Bellafill, and the 10 years of postmarketing experience of Bellafill since it received premarket approval (PMA) from the FDA as Artefill in 2006. Artefill was rebranded to Bellafill in 2015. The authors conducted a literature search on PubMed for key articles describing the steps in which Arteplast, a PMMA filler developed in 1989, led to the development of Bellafill, the only PMMA filler approved by the US FDA for the treatment of nasolabial folds and acne scar correction. The factors governing efficacy and safety were also evaluated for the major PMMA fillers available in the world. The process of manufacturing and purifying PMMA has played a major role in minimizing adverse events for Bellafill. Postmarketing surveillance data for the 2007-2016 period show that for more than 530 000 Bellafill syringes distributed worldwide, 11 confirmed granulomas (excluding clinical trial data) (0.002% of syringes sold) have been reported. Data on other PMMA fillers are limited and inconsistent. The authors suggest that adverse events are often attributable to lack of proficiency in treatment technique and other factors. Bellafill has demonstrated an excellent safety and effectiveness profile in multiple clinical studies, customer feedback, and 10 years of postmarketing surveillance experience. Adverse events occur with all fillers for a variety of reasons. In addition to quality of the product, injector skill and technique are critical to ensuring good clinical outcomes. © 2018 Wiley Periodicals, Inc.

Influence of matrix and filler fraction on biofilm formation on the surface of experimental resin-based composites.

PubMed

Ionescu, Andrei; Brambilla, Eugenio; Wastl, Daniel S; Giessibl, Franz J; Cazzaniga, Gloria; Schneider-Feyrer, Sibylle; Hahnel, Sebastian

2015-01-01

The aim of this study was to investigate the impact of resin matrix chemistry and filler fraction on biofilm formation on the surface of experimental resin-based composites (RBCs). Specimens were prepared from eight experimental RBC formulations differing in resin matrix blend (BisGMA/TEGDMA in a 7:3 wt% ratio or UDMA/aliphatic dimethacrylate in a 1:1 wt% ratio) and filler fraction (no fillers; 65 wt% dental glass with an average diameter of 7 or 0.7 µm or 65 wt% SiO2 with an average diameter of 20 nm). Surface roughness, surface free energy, and chemical surface composition were determined; surface topography was visualized using atomic force microscopy. Biofilm formation was simulated under continuous flow conditions for a 48 h period using a monospecies Streptococcus mutans and a multispecies biofilm model. In the monospecies biofilm model, the impact of the filler fraction overruled the influence of the resin matrix, indicating lowest biofilm formation on RBCs with nano-scaled filler particles and those manufactured from the neat resin blends. The multispecies model suggested a more pronounced effect of the resin matrix blend, as significantly higher biofilm formation was identified on RBCs with a UDMA/dimethacrylate matrix blend than on those including a BisGMA/TEGDMA matrix blend but analogous filler fractions. Although significant differences in surface properties between the various materials were identified, correlations between the surface properties and biofilm formation were poor, which highlights the relevance of surface topography and chemistry. These results may help to tailor novel RBC formulations which feature reduced biofilm formation on their surface.

Interface effects on mechanical properties of particle-reinforced composites.

PubMed

Debnath, S; Ranade, R; Wunder, S L; McCool, J; Boberick, K; Baran, G

2004-09-01

Effective bonding between the filler and matrix components typically improves the mechanical properties of polymer composites containing inorganic fillers. The aim of this study was to test the hypothesis that composite flexural modulus, flexure strength, and toughness are directly proportional to filler-matrix interfacial shear strength. The resin matrix component of the experimental composite consisted of a 60:40 blend of BisGMA:TEGDMA. Two levels of photoinitiator components were used: 0.15, and 0.5%. Raman spectroscopy was used to determine degree of cure, and thermogravimetry (TGA) was used to quantify the degree of silane, rubber, or polymer attachment to silica and glass particles. Filler-matrix interfacial shear strengths were measured using a microbond test. Composites containing glass particles with various surface treatments were prepared and the modulus, flexure strength, and fracture toughness of these materials obtained using standard methods. Mechanical properties were measured on dry and soaked specimens. The interfacial strength was greatest for the 5% MPS treated silica, and it increased for polymers prepared with 0.5% initiator compared with 0.15% initiator concentrations. For the mechanical properties measured, the authors found that: (1) the flexural modulus was independent of the type of filler surface treatment, though flexural strength and toughness were highest for the silanated glass; (2) rubber at the interface, whether bonded to the filler and matrix or not, did not improve toughness; (3) less grafting of resin to silanated filler particles was observed when the initiator concentration decreased. These findings suggest that increasing the strength of the bond between filler and matrix will not result in improvements in the mechanical properties of particulate-reinforced composites in contrast to fiber-reinforced composites. Also, contraction stresses in the 0.5 vs 0.15% initiator concentration composites may be responsible for increases in interfacial shear strengths, moduli, and flexural strengths.

Mechanical Properties of Polymer Nano-composites

NASA Astrophysics Data System (ADS)

Srivastava, Iti

Thermoset polymer composites are increasingly important in high-performance engineering industries due to their light-weight and high specific strength, finding cutting-edge applications such as aircraft fuselage material and automobile parts. Epoxy is the most widely employed thermoset polymer, but is brittle due to extensive cross-linking and notch sensitivity, necessitating mechanical property studies especially fracture toughness and fatigue resistance, to ameliorate the low crack resistance. Towards this end, various nano and micro fillers have been used with epoxy to form composite materials. Particularly for nano-fillers, the 1-100 nm scale dimensions lead to fascinating mechanical properties, oftentimes proving superior to the epoxy matrix. The chemical nature, topology, mechanical properties and geometry of the nano-fillers have a profound influence on nano-composite behavior and hence are studied in the context of enhancing properties and understanding reinforcement mechanisms in polymer matrix nano-composites. Using carbon nanotubes (CNTs) as polymer filler, uniquely results in both increased stiffness as well as toughness, leading to extensive research on their applications. Though CNTs-polymer nano-composites offer better mechanical properties, at high stress amplitude their fatigue resistance is lost. In this work covalent functionalization of CNTs has been found to have a profound impact on mechanical properties of the CNT-epoxy nano-composite. Amine treated CNTs were found to give rise to effective fatigue resistance throughout the whole range of stress intensity factor, in addition to significantly enhancing fracture toughness, ductility, Young's modulus and average hardness of the nano-composite by factors of 57%, 60%, 30% and 45% respectively over the matrix as a result of diminished localized cross-linking. Graphene, a one-atom-thick sheet of atoms is a carbon allotrope, which has garnered significant attention of the scientific community and is predicted to out-perform nanotubes. In the last few years, work has been done by researchers to study bulk mechanical properties of graphene platelets in polymer matrix. This thesis reports the extensive improvements observed in fatigue resistance and fracture toughness of epoxy using graphene platelet as a filler in very small quantities. Though significant property improvements like 75% increase in fracture toughness and 25-fold increase in fatigue resistance were observed for graphene epoxy nano-composites, the toughening mechanisms could not be delineated without thermo-mechanical and micro-mechanical tests. In this work, the bulk mechanical properties of graphene platelet-polymer nano-composites are studied and presented and the toughness mechanisms are identified by fractography, differential scanning calorimetry, and Raman spectroscopy; and then compared to predictions by theoretical models. Strong adherence to the matrix was found to be the key mechanism responsible for the effective reinforcement provided by graphene to the polymer. The strong graphene platelet-matrix interface also leads to extensive crack deflection, which was observed to be the major toughening mechanism in the nano-composite. In this thesis, the bulk mechanical property results are complemented by in-depth characterization of filler-polymer interfacial interactions and interphase formation using a battery of techniques including Raman spectroscopy and atomic force microscopy. Theoretical and empirical models proposed by Faber & Evans and Pezzotti were critically studied and applied. Pezzotti's model was found to corroborate well with experimental results and provided insight into enhancement mechanisms and explains the mechanisms underpinning the toughness loss at high graphene platelet weight fraction. The thesis provides conclusive evidences for the superiority of graphene as a filler for reinforcing polymer matrices. In conclusion, the thesis presents a thorough investigation of one- and two-dimensional carbon nanomaterials as fillers for high-performance polymer nano-composites. The extensive studies performed on graphene provide a strong foundation for graphene as a potential candidate for reinforcing polymers. The superior performance of graphene as a filler is attributed to graphene's high specific surface area, two-dimensional sheet geometry, strong filler-matrix adhesion and the outstanding mechanical properties of the sp2 carbon-bonding network in graphene. The improved mechanical properties of the graphene-polymer nano-composites, concurrent with the cost-effective production are both vital requirements of the industry in adoption of high strength-to-weight ratio polymer composites for various structural applications.

Preparation and characterization of zinc sulphide nanocomposites based on acrylonitrile butadiene rubber

NASA Astrophysics Data System (ADS)

Ramesan, M. T.; Nihmath, A.; Francis, Joseph

2013-06-01

Rubber composite based on acrylonitrile butadiene rubber (NBR) reinforced with nano zinc sulphide (ZnS) have been prepared via vulcanization process and characterized by several techniques. Processing characteristics such as scorch time, optimum cure time decreases with increase in concentration of nano filler in acrylonitrile butadiene rubber. Mechanical properties such as tensile and tear strength increases with increase in concentration of nano filler up to 7 phr of loading thereafter the value decreases, whereas hardness, and flame resistance increases with the dosage of fillers. These enhanced properties are due to the homogenous dispersion of nano fillers in NBR matrix, which is evidenced from the structure that evaluated using X-ray diffraction (XRD) and scanning electron microscopy (SEM).

Severe Acute Local Reactions to a Hyaluronic Acid-derived Dermal Filler

PubMed Central

Hays, Geoffrey P.; Caglia, Anthony E.; Caglia, Michael

2010-01-01

Injectable fillers are normally well tolerated by patients with little or no adverse effects. The most common side effects include swelling, redness, bruising, and pain at the injection site. This report describes three cases in which patients injected with a hyaluronic acid-derived injectable filler that is premixed with lidocaine developed adverse reactions including persistent swelling, pain, and nodule formation. Two of the three patients' abscesses were cultured for aerobic and anaerobic bacteria and mycobacterium. All three cultures were negative. Abscess persistence in all cases necessitated physical removal and/or enzymatic degradation with hyaluronidase. The effects subsided only after the product had been removed. Two of these patients were subsequently treated with other hyaluronic acid-derived dermal fillers without adverse events. PMID:20725567

Fracture resistant, antibiofilm adherent, self-assembled PMMA/ZnO nanoformulations for biomedical applications: physico-chemical and biological perspectives of nano reinforcement

NASA Astrophysics Data System (ADS)

Raj, Indu; Mozetic, Miran; Jayachandran, V. P.; Jose, Jiya; Thomas, Sabu; Kalarikkal, Nandakumar

2018-07-01

Antimicrobial, antibiofilm adherent, fracture resistant nano zinc oxide (ZnO NP) formulations based on poly methyl methacrylate (PMMA) matrix were developed using a facile ex situ compression moulding technique. These formulations demonstrated potent, long-term biofilm-resisting effects against Candida albicans (9000 CFU to 1000 CFU) and Streptococcus mutans. Proposed mechanism of biofilm resistance was the release of metallic ions/metal oxide by ‘particle-corrosion’. MTT and cellular proliferation assays confirmed both qualitatively and quantitatively equal human skin fibroblast cell line proliferations (approximately 75%) on both PMMA/ZnO formulation and neat PMMA. Mechanical performance was evaluated over a range of filler loading, and theoretical models derived from Einstein, Guth, Thomas and Quemade were chosen to predict the modulus of the nanoformulations. All the models gave better fitting at lower filler content, which could be due to restricted mobility of the polymer chains by the constrained zone/interfacial rigid amorphous zone and also due to stress absorption by the highly energized NPs. Fracture mechanics were clearly described based on substantial experimental evidence surrounding crack prevention in the initial zones of fracture. Filler‑polymer interactions at the morphological and structural levels were elucidated through FTIR, XRD, SEM, TEM and AFM analyses. Major clinical challenges in cancer patient rehabilitation and routine denture therapy are frequent breakage of the prostheses and microbial colonization on the prostheses/tissues. In the present study, we succeeded in developing an antimicrobial, mechanically improved fracture resistant, biocompatible nanoformulation in a facile manner without the bio-toxic effects of surface modifiers/functionalization. This PMMA/ZnO nanoformulation could serve as a cost effective breakthrough biomaterial in the field of prosthetic rehabilitation and local drug delivery scaffolds for abused tissues.

Industrial-grade silicone injections causing intermittent bilateral malar swelling: review of safety and efficacy of techniques and products available.

PubMed

Seward, Austin C; Meara, Daniel J

2013-07-01

Silicone and other fillers have become a popular aid to increase soft tissue density, decrease static skin rhytids, and treat muscle wasting, particularly in the face. As a result, injectable silicone has become popular in patients with the human immunodeficiency virus (HIV). It has been postulated that highly active antiretroviral therapy detrimentally induces the physiologic process of fat atrophy of the temporal and buccal fat pads of the face and regional fat wasting of the arms, legs, and buttocks and that HIV protease inhibitors may induce fat atrophy by binding and inhibiting homologous human proteins that are involved in fat metabolism. The classic hollowed-out facial appearance linked to HIV positivity can have detrimental social implications in infected patients who are otherwise very functional. In consequence, facial implantation, fat transplantation, and dermal and subcutaneous fillers have been used to aid in the restoration of facial appearance. This report describes the case of a patient who underwent multiple rounds of silicone injections and complained of intermittent facial swelling and pain long after the injections. The authors report on the safety of specific medical-grade injectable fillers and techniques found to be safely effective, especially in the HIV-positive population. Copyright © 2013 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Gellan Gum-based luminal fillers for peripheral nerve regeneration: an in vivo study in the rat sciatic nerve repair model.

PubMed

Carvalho, C R; Wrobel, S; Meyer, C; Brandenberger, C; Cengiz, I F; López-Cebral, R; Silva-Correia, J; Ronchi, G; Reis, R L; Grothe, C; Oliveira, J M; Haastert-Talini, K

2018-05-01

Peripheral nerve injuries (PNI) resulting in a gap to be bridged between the transected nerve ends are commonly reconstructed with autologous nerve tissue, but there is a need for valuable alternatives. This experimental work considers the innovative use of the biomaterial Gellan Gum (GG) as a luminal filler for nerve guidance channels made from chitosan with a 5% degree of acetylation. The engineered constructs should remodel the structural support given to regenerating axons by the so-called bands of Büngner. Four different GG formulations were produced by combining varying amounts of High-Acyl GG (HA-GG) and Methacrylated GG (MA-GG). The effective porosity of the freeze-dried networks was analysed by SEM and micro-CT 3D reconstructions, while the degradation and swelling abilities were characterized in vitro for up to 30 days. The metabolic activity and viability of immortalized Schwann cells seeded onto the freeze-dried networks were also evaluated. Finally, the developed hydrogel formulations were freeze-dried within the chitosan nerve guides and implanted in a 10 mm rat sciatic nerve defect. Functional and histomorphological analyses after 3, 6, and 12 weeks in vivo revealed that although it did not result in improved nerve regeneration, the NGC25:75 formulations could provide a basis for further development of GG scaffolds as luminal fillers for hollow nerve guidance channels.

Brazilian Consensus Recommendation on the Use of Polymethylmethacrylate Filler in Facial and Corporal Aesthetics.

PubMed

Blanco Souza, Túlio Armanini; Colomé, Letícia Marques; Bender, Eduardo André; Lemperle, Gottfriede

2018-06-05

Considering that aesthetic benefits can be obtained with the use of permanent filling materials, this work focuses on the development of a consensus regarding the facial and corporal use of polymethylmethacrylate (PMMA) filler in Brazil. A questionnaire regarding PMMA treatment, which included items on the main indication, application site, volume of product applied, criteria for selection of the material, complications, contraindications, and individual professional experience, was distributed to the Expert Group members. In addition, the responses were summarized, constituting the starting point for the debate regarding the use of PMMA-based fillers on The First Brazilian PMMA Symposium to create a guideline to be followed in PMMA facial and corporal treatments. This survey involved 87,371 cases. PMMA treatment is recommended for restorative and aesthetic purposes in facial and corporal cases, particularly for facial balance. PMMA 30% filler is recommended in specific facial sites (nose, mentum, mandible angle, zygomatic arc, and malar). PMMA filler is contraindicated in other sites (lips) regardless of concentration. With regard to facial treatment, the juxtaperiostal is the application plane most recommended. For PMMA corporal application, intramuscular is the application plane most indicated, while intradermal and justadermal planes are contraindicated. The submuscular plane application is relative to PMMA filler concentration. The experts also inquired regarding the amount of PMMA recommended in each corporal site (50 mL in the calf, 100-150 mL in the gluteal region). These recommendations provide a guideline for physicians, supporting them to perform safe and efficacious treatment with PMMA fillers. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Thermal Conductivity of Epoxy Resin Composites Filled with Combustion Synthesized h-BN Particles.

PubMed

Chung, Shyan-Lung; Lin, Jeng-Shung

2016-05-20

The thermal conductivity of epoxy resin composites filled with combustion-synthesized hexagonal boron nitride (h-BN) particles was investigated. The mixing of the composite constituents was carried out by either a dry method (involving no use of solvent) for low filler loadings or a solvent method (using acetone as solvent) for higher filler loadings. It was found that surface treatment of the h-BN particles using the silane 3-glycidoxypropyltrimethoxysilane (GPTMS) increases the thermal conductivity of the resultant composites in a lesser amount compared to the values reported by other studies. This was explained by the fact that the combustion synthesized h-BN particles contain less -OH or active sites on the surface, thus adsorbing less amounts of GPTMS. However, the thermal conductivity of the composites filled with the combustion synthesized h-BN was found to be comparable to that with commercially available h-BN reported in other studies. The thermal conductivity of the composites was found to be higher when larger h-BN particles were used. The thermal conductivity was also found to increase with increasing filler content to a maximum and then begin to decrease with further increases in this content. In addition to the effect of higher porosity at higher filler contents, more horizontally oriented h-BN particles formed at higher filler loadings (perhaps due to pressing during formation of the composites) were suggested to be a factor causing this decrease of the thermal conductivity. The measured thermal conductivities were compared to theoretical predictions based on the Nielsen and Lewis theory. The theoretical predictions were found to be lower than the experimental values at low filler contents (< 60 vol %) and became increasing higher than the experimental values at high filler contents (> 60 vol %).

Synthesis of wrinkled mesoporous silica and its reinforcing effect for dental resin composites.

PubMed

Wang, Ruili; Habib, Eric; Zhu, X X

2017-10-01

The aim of this work is to explore the reinforcing effect of wrinkled mesoporous silica (WMS), which should allow micromechanical resin matrix/filler interlocking in dental resin composites, and to investigate the effect of silica morphology, loading, and compositions on their mechanical properties. WMS (average diameter of 496nm) was prepared through the self-assembly method and characterized by the use of the electron microscopy, dynamic light scattering, and the N 2 adsorption-desorption measurements. The mechanical properties of resin composites containing silanized WMS and nonporous smaller silica were evaluated with a universal mechanical testing machine. Field-emission scanning electron microscopy was used to study the fracture morphology of dental composites. Resin composites including silanized silica particles (average diameter of 507nm) served as the control group. Higher filler loading of silanized WMS substantially improved the mechanical properties of the neat resin matrix, over the composites loaded with regular silanized silica particles similar in size. The impregnation of smaller secondary silica particles with diameters of 90 and 190nm, denoted respectively as Si90 and Si190, increased the filler loading of the bimodal WMS filler (WMS-Si90 or WMS-Si190) to 60wt%, and the corresponding composites exhibited better mechanical properties than the control fillers made with regular silica particles. Among all composites, the optimal WMS-Si190- filled composite (mass ratio WMS:Si190=10:90, total filler loading 60wt%) exhibited the best mechanical performance including flexural strength, flexural modulus, compressive strength and Vickers microhardness. The incorporation of WMS and its mixed bimodal fillers with smaller silica particles led to the design and formulation of dental resin composites with superior mechanical properties. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Three-body wear of resin denture teeth with and without nanofillers.

PubMed

Stober, Thomas; Henninger, Moritz; Schmitter, Marc; Pritsch, Maria; Rammelsberg, Peter

2010-02-01

The wear behavior of newly developed denture teeth with nanofillers may be different from teeth with other chemical formulations. The purpose of this study was to examine the 3-body wear resistance of 11 different commercially available resin denture teeth. The materials tested were conventional (SR Orthotyp PE, Orthognath) and cross-linked acrylic resin teeth without inorganic fillers (Premium 8, SR Postaris DCL, Trubyte Portrait, Artiplus), composite resin teeth with inorganic fillers (SR Orthosit PE, Vitapan), and composite resin teeth (experimental materials) with inorganic nanofillers (NC Veracia Posterior, e-Ha, Mondial). Human enamel and a ceramic denture tooth (Lumin Vacuum) were used as reference materials. The 3-body wear test was performed in a wear machine developed by the Academic Center for Dentistry Amsterdam (ACTA), with millet suspension acting as an abrasive medium (n=10, test load: 15 N, slip rate: 20%, number of cycles: 100,000). Wear was determined with the aid of a profilometer. Data were analyzed with the Kruskal-Wallis test and Mann-Whitney U test using the closed testing approach (significance level for familywise error rate, alpha=.05). None of the acrylic and composite resin materials tested in this study demonstrated the 3-body wear resistance of ceramic teeth or human enamel. Teeth with inorganic fillers demonstrated significantly lower wear values than conventional or cross-linked acrylic resin teeth without fillers. Composite resin teeth with traditional fillers showed significantly lower wear than composite resin teeth with nanofillers. Denture teeth with and without inorganic fillers differed significantly with regard to the degree of wear generated in the ACTA wear simulator. The incorporation of nanofillers did not improve the wear resistance compared to teeth with traditional fillers.

Properties, sustainability and elevated temperature behavior of concrete containing Portland limestone cement

NASA Astrophysics Data System (ADS)

El-Hawary, Moetaz; Ahmed, Mahmoud

2017-09-01

The utilization of some type of cheap filler as partial cement replacement is an effective way of improving concrete sustainability. With the recent trends to reduce water to cement ratio and improve compaction, there is no enough space or water for complete hydration of cement. This means that actually, a portion of mixed cement acts as expensive filler. Replacing this portion with cheaper filler that requires less energy to produce is, therefore, beneficial. Crushed limestone is the most promising filler. This work is to investigate the effect of the amount of limestone fillers on the sustainability and the fresh and mechanical properties of the resulting concrete. A rich mix is designed with a low water/cement ratio of 0.4. Lime is introduced as a replacement percentage of cement. Ratios of 0, 10, 20 and 30% were used. Slump, compressive strength, specific gravity and water absorption are evaluated for every mix. In addition, the effect of the amount of lime on the residual strength of concrete subjected to elevated temperatures is also investigated. Samples are subjected to six different temperature stations of 20, 100, 200, 300, 500 and 700°C for six hours before being cooled and subsequently tested for compressive strength and specific gravity. Sustainability of the tested mixes is evaluated through reductions in the emitted carbon dioxide, energy and reduction in cost. Based on the annual use of concrete in Kuwait, the sustainability benefits resulting from the use of limestone filler in Kuwait are evaluated and assessed. The paper is concluded with the recommendation of the use of 15% limestone filler as partial cement replacement where the properties and the behavior under high temperature of the resulting concrete are almost the same as those of conventional concrete with considerable cost and sustainability benefits.

NanoRelease: Pilot interlaboratory comparison of a weathering protocol applied to resilient and labile polymers with and without embedded carbon nanotubes

EPA Science Inventory

A major use of multi-walled carbon nanotubes (MWCNTs) is as functional fillers embedded in a solid matrix, such as plastics or coatings. Weathering and abrasion of the solid matrix during use can lead to environmental releases of the MWCNTs. Here we focus on a protocol to identif...

Time Neutron Technique for UXO Discrimination

DTIC Science & Technology

2010-12-01

mixture of TNT and RDX C-4 CFD Composition 4 military plastic explosive Constant Fraction Discriminator Cps CsI counts per second inorganic...Pdfs Probability Density Functions PET Positron Emission Tomography Pfa Probability of False Alarm PFTNA Pulsed Fast/Thermal Neutron Analysis PMTs...the ordnance type (rocket, mortar , projectile, etc.) and what filler material it contains (inert or empty), practice, HE, illumination, chemical (i.e

Structural Studies of dielectric HDPE+ZrO2 polymer nanocomposites: filler concentration dependences

NASA Astrophysics Data System (ADS)

Nabiyev, A. A.; Islamov, A. Kh; Maharramov, A. M.; Nuriyev, M. A.; Ismayilova, R. S.; Doroshkevic, A. S.; Pawlukojc, A.; Turchenko, V. A.; Olejniczak, A.; Rulev, M. İ.; Almasan, V.; Kuklin, A. I.

2018-03-01

Structural properties of HDPE+ZrO2 polymer nanocomposites thin films of 80-100μm thicknesses were investigated using SANS, XRD, Laser Raman and FTIR spectroscopy. The mass fraction of the filler was 1, 3, 10, and 20%. Results of XRD analysis showed that ZrO2 powder was crystallized both in monoclinic and in cubic phase under normal conditions. The percentages of monoclinic and cubic phase were found to be 99.8% and 0.2%, respectively. It was found that ZrO2 nanoparticles did not affect the main crystal and chemical structure of HDPE, but the degree of crystallinity of the polymer decreases with increasing concentration of zirconium oxide. SANS experiments showed that at ambient conditions ZrO2 nanoparticles mainly distributed like mono-particles in the polymer matrix at all concentrations of filler.The structure of HDPE+ZrO2 does not changes up to 132°C at 1-3% of filler, excepting changing of the polymer structure at temperatures upper 82°C. At high concentrations of filler 10-20% the aggregation of ZrO2 nanoparticles occurs, forming domains of 2.5μm. The results of Raman and FTIR spectroscopy did not show additional specific chemical bonds between the filler and the polymer matrix. New peaks formation was not observed. These results suggest that core-shell structure does not exist in the polymer nanocomposite system.

Fabrication and anti-microbial evaluation of drug loaded polylactide space filler intended for ridge preservation following tooth extraction

PubMed Central

Thomas, Nebu George; Sanil, George P.; Rajmohan, Gopimohan; Prabhakaran, Jayachandran V.; Panda, Amulya K.

2011-01-01

Background: The preservation or reduction of alveolar ridge resorption following tooth extraction is important in patients especially for those intended for implants at a later stage. One way to achieve this is by using membranes, graft materials, and biodegradable space fillers to prevent alveolar bone resorption and promote regeneration. A major attraction for using biodegradable and biocompatible polymers as space fillers for ridge preservation is their safety profile in comparison to xenograft materials like lyophilized bone and collagen. Materials and Methods: Biocompatible polylactide space fillers were fabricated by fusing porous polylactide particles. The sponges were loaded with drugs by placing them in the respective solutions. Pseudomonas aeruginosa was isolated from a chronic periodontitis patient and in vitro anti-microbial evaluation was done with the drug loaded sponges. Results: Chlorhexidine loaded space filler showed significant anti microbial effect against multiple drug resistant Pseudomonas aeruginosa isolated from a patient with chronic periodontitis. Conclusion: The results of this study indicate that biodegradable drug releasing polylactide space fillers has the potential to be used for ridge preservation following tooth extraction. Release of drugs in the socket may prove useful in preventing development of alveolar osteitis post extraction which can interfere with normal healing of the socket. Synthetic biodegradable polymers also exhibit a controlled degradation rate to achieve complete resorption within the intended time. PMID:22028514

Mechanical properties of chemically modified Sansevieria trifasciata/natural rubber/high density polyethylene (STF/NR/HDPE) composites: Effect of silane coupling agent

NASA Astrophysics Data System (ADS)

Zakaria, Nurzam Ezdiani; Baharum, Azizah; Ahmad, Ishak

2018-04-01

The main objective of this research is to study the effects of chemical modification on the mechanical properties of treated Sansevieria trifasciata fiber/natural rubber/high density polyethylene (TSTF/NR/HDPE) composites. Processing of STF/NR/HDPE composites was done by using an internal mixer. The processing parameters used were 135°C for temperature and a mixing rotor speed of 55 rpm for 15 minutes. Filler loading was varied from 10% to 40% of STF and the fiber size used was 125 µm. The composite blends obtained then were pressed with a hot press machine to get test samples of 1 mm and 3 mm of thickness. Samples were evaluated via tensile tests, Izod impact test and scanning electron microscopy (SEM). Results showed that tensile strength and strain value decreased while tensile modulus increased when filler loading increased. Impact strength increased when filler loading increased and began to decrease after 10% of filler amount for treated composites. For untreated composites, impact strength began to decrease after 20% of filler loading. Chemical modification by using silane coupling agent has improved certain mechanical properties of the composites such as tensile strength, strain value and tensile modulus. Adding more amount of filler will also increase the viscosity and the stiffness of the materials.

Advanced Ceramics from Preceramic Polymers Modified at the Nano-Scale: A Review.

PubMed

Bernardo, Enrico; Fiocco, Laura; Parcianello, Giulio; Storti, Enrico; Colombo, Paolo

2014-03-06

Preceramic polymers, i.e. , polymers that are converted into ceramics upon heat treatment, have been successfully used for almost 40 years to give advanced ceramics, especially belonging to the ternary SiCO and SiCN systems or to the quaternary SiBCN system. One of their main advantages is the possibility of combining the shaping and synthesis of ceramics: components can be shaped at the precursor stage by conventional plastic-forming techniques, such as spinning, blowing, injection molding, warm pressing and resin transfer molding, and then converted into ceramics by treatments typically above 800 °C. The extension of the approach to a wider range of ceramic compositions and applications, both structural and thermo-structural (refractory components, thermal barrier coatings) or functional (bioactive ceramics, luminescent materials), mainly relies on modifications of the polymers at the nano-scale, i.e. , on the introduction of nano-sized fillers and/or chemical additives, leading to nano-structured ceramic components upon thermal conversion. Fillers and additives may react with the main ceramic residue of the polymer, leading to ceramics of significant engineering interest (such as silicates and SiAlONs), or cause the formation of secondary phases, significantly affecting the functionalities of the polymer-derived matrix.

Tuning filler shape, surface chemistry and ion content in nanofilled polymer electrolytes

NASA Astrophysics Data System (ADS)

Ganapatibhotla, Lalitha V. N. R.

We investigate how nanofiller surface chemistry and aspect ratio affect the performance of nanofilled solid polymer electrolytes. Polymer-based electrolytes are an attractive alternative to the organic electrolytes currently used in lithium ion batteries. We characterize acidic nanoparticle filled electrolytes and compare them to neutral particle-filled electrolytes previously measured in our lab. Dielectric spectroscopy measurements indicate that the highest increase in conductivity occurs at the eutectic composition (EO/Li=10) and is independent of filler surface chemistry. We measure PEO dynamics using quasi-elastic neutron scattering and do not observe any change in polymer dynamics with particle surface chemistry. When we examine the elastic incoherent structure factor associated with the rotational process, fillers are found to restrict the rotation of the highly conducting PEO6:LiClO4 tunnels. At the eutectic composition, these tunnels are stabilized at the filler surface even above PEO melting temperature. Marginal stability theory predicts formation of alternating layers of coexisting phases at the eutectic composition. We propose a new mechanism, via stabilization of alternating layers of PEO and highly conducting PEO 6:LiClO4 tunnels at the filler surface. When compared to spherical particles, more such structures would be stabilized at a filler surface with high aspect ratio. Consistent with this hypothesis, neutral gamma-Al2O3 nanowhiskers (2-4 nm in diameter and 200-400 nm in length) intensify the effect of neutral gamma-Al 2O3 nanoparticles. The diameters of the two fillers are similar, but the change in aspect ratio (1 to 100) improves conductivity by a factor of 5. This enhancement occurs at battery operation temperatures! Although the change in aspect ratio does not affect thermal transitions and segmental dynamics at optimal whisker loading, the rotation of PEO6 remnants is distinct at the eutectic composition. Because the mechanism by which nanofillers enhance conductivity is related to stabilization of conducting structures at the filler-electrolyte interface, we determine the interface morphology using neutron reflectometry. For this, we spin-coat the unfilled electrolytes EO/Li = 8, 10 on sapphire substrate, which has the same surface chemistry as alpha-Al2O3. When freshly-spin coated on sapphire substrate, the non-eutectic sample does not exhibit any segregation of layers. The freshly spin-coated eutectic sample forms layers with alternating high and low salt concentrations, very similar to the eutectic lamellae predicted by the marginal stability theory for eutectic solidification. Such lamellae do not develop further when the sample is annealed at eutectic temperature and the salt concentration in the polymer decreases gradually away from the surface of sapphire. To take fullest advantage of the surface mechanism and obtain larger increases in conductivity we tailor the aspect ratio of high aspect ratio fillers. Commercial availability of alumina nanowhiskers is limited to neutral surface chemistry and aspect ratio of 100, cellulose nanowhiskers provide a model system where a wide range of surface chemistries may be accessed with variable aspect ratio. We synthesized cellulose whiskers of two different aspect ratios [cotton whiskers: aspect ratio ˜ 10, acetobacter whiskers: aspect ratio ˜ 200] and tested their influence on conductivity and morphology of polymer electrolytes. Similar to all fillers studied in this work, both types of cellulose whiskers provide highest increase in conductivity at the eutectic composition, with the longer acetobacter whiskers providing a marginally higher increase than the cotton whiskers. Although both cellulose whiskers do not alter the crystallinity or glass transition temperature at the optimal 1 wt% loading, they amplify the faint cold crystallization behavior observed in the unfilled eutectic electrolyte without changing the overall crystallinity. At the non-eutectic compositions, cellulose whiskers behave similar to the acidic nanoparticles. To determine the function of nanofillers in entire composition range of the phase diagram, we extend the range of measurements on the nanofilled PEO+LiClO4 electrolyte to EO/Li = 4 to 100. Because PEO+LiAsF 6 electrolytes have similar phase diagram as the PEO+LiClO4 electrolytes, we augment the study of nanofilled PEO+LiAsF6 complexes to the PEO+LiClO4 electrolytes. At compositions near the high and low ends of the phase diagram, the effect of nanofillers on conductivity is governed by reduction in crystallinity of PEO and PEO-salt complexes. In the absence of PEO6, fillers interact directly with PEO and suppress crystallization. This is consistent with the reflectometry experiment where sapphire surface prefers to interact with the salt-rich layers. Around the eutectic composition fillers restrict the highly conducting PEO6 complex at their surface and any increase in conductivity is due to stabilization of these conducting tunnels. For room temperature applications, lithium hexafluoroarsenate seems to be the better salt than lithium perchlorate. At temperatures higher than the eutectic temperature (50°C), conductivity levels off at the value set by the eutectic composition. (Abstract shortened by ProQuest.).

Mechanically Strong Aerogels Formed by Templated Growth of Polymer Cross- Linkers on Inorganic Nanoparticles

NASA Technical Reports Server (NTRS)

Leventis, Nicholas; Fabrizio, Eve F.; Johnston, Chris; Meador, Maryann

2004-01-01

In the search for materials with better mechanical, thermal, and electrical properties, it is becoming evident that oftentimes dispersing ceramic nanoparticles in plastics improves performance. Along these lines, chemical bonding (both covalent and noncovalent) between a filler and a polymer improves their compatibility, and thus enhances certain properties of the polymeric matrix above and beyond what is accomplished by simple doping with the filler. When a similarly sized dopant and matrix are used, elementary building blocks may also have certain distinct advantages (e.g., in catalysis). In this context, researchers at the NASA Glenn Research Center reasoned that in the extreme case, where the dopant and the matrix (e.g., a filler and a polymer) are not only sized similarly, but their relative amounts are comparable, the relative roles of the dopant and matrix can be reversed. Then, if the "filler," or a certain form thereof, possesses desirable properties of its own, such properties could be magnified by cross-linking with a polymer. We at Glenn have identified silica as such a filler in its lowest-density form, namely the silica aerogel.

Influence of fillers on the alkali activated chamotte

NASA Astrophysics Data System (ADS)

Dembovska, L.; Bumanis, G.; Vitola, L.; Bajare, D.

2017-10-01

Alkali-activated materials (AAM) exhibit remarkable high-temperature resistance which makes them perspective materials for high-temperature applications, for instance as fire protecting and insulating materials in industrial furnaces. Series of experiments were carried out to develop optimum mix proportions of AAM based on chamotte with quartz sand (Q), olivine sand (OL) and firebrick sawing residues (K26) as fillers. Aluminium scrap recycling waste was considered as a pore forming agent and 6M NaOH alkali activation solution has been used. Lightweight porous AAM have been obtained with density in range from 600 to 880 kg/m3 and compressive strength from 0.8 to 2.7 MPa. The XRD and high temperature optical microscopy was used to characterize the performance of AAM. The mechanical, physical and structural properties of the AAM were determined after the exposure to elevated temperatures at 800 and 1000°C. The results indicate that most promising results for AAM were with K26 filler where strength increase was observed while Q and OL filler reduced mechanical properties due to structure deterioration caused by expansive nature of selected filler.

Physical Metallurgy, Weldability, and in-Service Performance of Nickel-Chromium Filler Metals Used in Nuclear Power Systems

NASA Astrophysics Data System (ADS)

Young, George A.; Etien, Robert A.; Hackett, Micah J.; Tucker, Julie D.; Capobianco, Thomas E.

Wrought Alloy 690 is well established for corrosion resistant nuclear applications but development continues to improve the weldability of a filler metal that retains the corrosion resistance and phase stability of the base metal. High alloy Ni-Cr filler metals are prone to several types of welding defects and new alloys are emerging for commercial use. This paper uses experimental and computational methods to illustrate key differences among welding consumables. Results show that solidification segregation is critical to understanding the weldability and environmentally-assisted cracking resistance of these alloys. Primary water stress corrosion cracking tests show a marked decrease in crack growth rates near 21 wt. % Cr at the grain boundary. While filler metals with 21-29 wt.% grain boundary Cr show similar PWSCC resistance, the higher alloyed grades are more prone to solidification cracking. Modeling and aging studies indicate that in some filler metals minor phase formation (e.g., Laves and σ) and long range order (LRO) must be assessed to ensure adequate weldability and inservice performance.

Fundamental studies to elucidate the protection mechanism (s) for making intelligent choices of coatings used in oil and gas production

NASA Astrophysics Data System (ADS)

Aljassem, Nasser Ashoor

Considerable attention has been given by the industries and researchers to develop the organic coating systems because of their importance in protecting and maintaining the integrity of the internal surfaces of oil and gas pipelines against corrosive solutions. Oil and natural gas pipelines mostly encounter both corrosion and wear degradations. The current study focuses on the development of coating systems by incorporating various types and amounts of fillers that are improving its barrier function to ward off the internal pipeline surfaces from the corrosive constituents. Simultaneously, fillers enhance the mechanical property of the coating systems that are capable of resisting a physical wear damage. The coating systems ranged in thickness and with micro to nano-size fillers. The pin-ball wear process, with two loads (100 N and 200 N), were applied on the surfaces of the coating systems. The hardness and reduced Young's modulus of the coated surfaces were characterized. The effect of the wear process with different loads were evaluated by employing a three dimensions (3D)-image profile-meter. A simulation of the sweet (CO2) and sour (CO2 and H2S) environments, with 2000 ppm Cl - ions, pH 4, at (60 °C and 1 bar), and (100 °C and 100 bar), respectively, used in the oil and gas industry were used to immerse and evaluate the coating systems. The coating system surface topographies, after the exposure to corrosive solutions, were evaluated by the 3-D profile-meter, stereoscope and scanning electron microscopy (SEM). The intentional defects imposed on the coating systems were exposed to corrosive solutions and their performance were periodically studied by the electrochemical impedance spectroscopy (EIS) technique. The electrochemical actions and coating system degradations due to the exposure to the corrosive solution were studied by the equivalent circuit models. The calculated EIS parameters were used to understand the interactions between the coating systems and corrosive solution. The effect of the high-load wear process was not considerable on the coating systems with significant amount of fillers. The coating systems with high amount of conductive and non-conductive fillers significantly showed high impedance in both the intact coating case and the highest coating resistance in case of the surface with intentional defects. No critical impact of the harsh environment with high pressure and temperature was observed on the powder phenolic Novolac coating system with defects. The harsh corrosive environment (sour), with high pressure and temperature, had a significant impact on most of the coating systems with defects and, specifically, the coating system that had carbon nanotube fillers. Protection and degradation mechanisms of the coating systems have been proposed.

Rheologic properties of flowable, conventional hybrid, and condensable composite resins.

PubMed

Lee, In-Bog; Son, Ho-Hyun; Um, Chung-Moon

2003-06-01

This research was undertaken to investigate the viscoelastic properties related to handling characteristics of five commercial flowable, two conventional hybrid and two condensable composite resins and to investigate the effect on the viscosity of filler volume fraction of composites. A dynamic oscillatory shear test was used to evaluate the storage shear modulus (G'), loss shear modulus (G"), loss tangent (tan delta) and complex viscosity (eta(*)) of the composite resins as a function of frequency (omega)-dynamic frequency sweep test from 0.01 to 100 rad/s at 25 degrees C-using an Advanced Rheometric Expansion System. To investigate the effect on the viscosity of the composites of the filler volume fraction, the filler weight% and filler volume% were measured by the Archimedes' principle using a pyknometer. The complex viscosity eta(*) of flowable composites was lower than that of the hybrid composites and significant differences were observed between brands. The complex viscosity eta(*) of condensable composites was higher than that of hybrid composites. The order of complex viscosity eta(*) at omega=10 rad/s in order of decreasing viscosity was as follows, Synergy compact, P-60, Z-250, Z-100, Aeliteflo, Tetric flow, Compoglass flow, Flow it and Revolution. The complex viscosity of flowable composites, normalized with respect to Z-100, was 0.04-0.56 but Synergy compact was 2.158 times higher than that of Z-100. The patterns of the change of loss tangent (tan delta) of the composite resins with increasing frequency were significantly different between brands. Phase angles delta ranged from 30.9 to 78.1 degrees at omega=10 rad/s. All composite resins exhibit pseudoplastic behavior with increasing shear rate. The relationships between the complex shear modulus G(*), the phase angle delta, and the shear rate omega were represented by the frequency domain phasor form, G(*)(omega)=G(*)e(i delta)=G(*) 90 degree angle delta. Only a weak relationship was found between filler volume% and the viscosity of the composite resins. This investigation shows that the viscoelasticity of composites in the same class is significantly different between brands. This rheologic property of composite resins influences the handling characteristics of the materials. The locus of frequency domain phasor plots in a complex plane is a valuable method of representing the viscoelastic properties of composite resins.

High temperature insulation for ceramic matrix composites

DOEpatents

Merrill, Gary B.; Morrison, Jay Alan

2001-01-01

A ceramic composition is provided to insulate ceramic matrix composites under high temperature, high heat flux environments. The composition comprises a plurality of hollow oxide-based spheres of various dimensions, a phosphate binder, and at least one oxide filler powder, whereby the phosphate binder partially fills gaps between the spheres and the filler powders. The spheres are situated in the phosphate binder and the filler powders such that each sphere is in contact with at least one other sphere. The spheres may be any combination of Mullite spheres, Alumina spheres, or stabilized Zirconia spheres. The filler powder may be any combination of Alumina, Mullite, Ceria, or Hafnia. Preferably, the phosphate binder is Aluminum Ortho-Phosphate. A method of manufacturing the ceramic insulating composition and its application to CMC substrates are also provided.

High temperature insulation for ceramic matrix composites

DOEpatents

Merrill, Gary B.; Morrison, Jay Alan

2000-01-01

A ceramic composition is provided to insulate ceramic matrix composites under high temperature, high heat flux environments. The composite comprises a plurality of hollow oxide-based spheres of varios dimentions, a phosphate binder, and at least one oxide filler powder, whereby the phosphate binder partially fills gaps between the spheres and the filler powders. The spheres are situated in the phosphate binder and the filler powders such that each sphere is in contact with at least one other sphere. The spheres may be any combination of Mullite spheres, Alumina spheres, or stabilized Zirconia spheres. The filler powder may be any combination of Alumina, Mullite, Ceria, or Hafnia. Preferably, the phosphate binder is Aluminum Ortho-Phosphate. A method of manufacturing the ceramic insulating composition and its application to CMC substates are also provided.

High temperature insulation for ceramic matrix composites

DOEpatents

Merrill, Gary B.; Morrison, Jay Alan

2004-01-13

A ceramic composition is provided to insulate ceramic matrix composites under high temperature, high heat flux environments. The composition comprises a plurality of hollow oxide-based spheres of various dimensions, a phosphate binder, and at least one oxide filler powder, whereby the phosphate binder partially fills gaps between the spheres and the filler powders. The spheres are situated in the phosphate binder and the filler powders such that each sphere is in contact with at least one other sphere. The spheres may be any combination of Mullite spheres, Alumina spheres, or stabilized Zirconia spheres. The filler powder may be any combination of Alumina, Mullite, Ceria, or Hafnia. Preferably, the phosphate binder is Aluminum Ortho-Phosphate. A method of manufacturing the ceramic insulating composition and its application to CMC substrates are also provided.

Update on botulinum toxin and dermal fillers.

PubMed

Berbos, Zachary J; Lipham, William J

2010-09-01

The art and science of facial rejuvenation is an ever-evolving field of medicine, as evidenced by the continual development of new surgical and nonsurgical treatment modalities. Over the past 10 years, the use of botulinum toxin and dermal fillers for aesthetic purposes has risen sharply. Herein, we discuss properties of several commonly used injectable products and provide basic instruction for their use toward the goal of achieving facial rejuvenation. The demand for nonsurgical injection-based facial rejuvenation products has risen enormously in recent years. Used independently or concurrently, botulinum toxin and dermal filler agents offer an affordable, minimally invasive approach to facial rejuvenation. Botulinum toxin and dermal fillers can be used to diminish facial rhytides, restore facial volume, and sculpt facial contours, thereby achieving an aesthetically pleasing, youthful facial appearance.

Randomized, Evaluator-Blinded Study Comparing Safety and Effect of Two Hyaluronic Acid Gels for Lips Enhancement.

PubMed

Hilton, Said; Sattler, Gerhard; Berg, Anna-Karin; Samuelson, Ulf; Wong, Cindy

2018-02-01

Hyaluronic acid (HA) fillers may differ in terms of gel characteristics and ease of use and it is of interest whether this might affect safety and duration of effect. To compare the long-term safety and effect of 2 HA fillers produced by 2 different technologies for lip enhancement. Subjects with very thin to moderately thick lips were randomized and treated with HA-RK (N = 31) or HA-JV (N = 29) to improve lip fullness by ≥ 1 grade on a 5-point scale, using a maximum of 3 mL of product. A smaller volume of HA-RK compared with HA-JV was required to improve lip fullness by ≥ 1 grade (mean: 1.54 mL vs 1.94 mL, p < .001). Despite the smaller volume, lip fullness and global aesthetic improvement were comparably sustained in both groups. At 6 months, 60.0% versus 57.7% of subjects (HA-RK vs HA-JV) had improved lip fullness. At 12 months, 71.4% versus 76.0% had aesthetic improvement (blinded evaluations) and 85.7% versus 86.2% felt more attractive. Both products were well tolerated. Both products achieved durable improvement in lip fullness and aesthetic appearance. A significantly smaller amount of HA-RK was required compared with HA-JV to achieve optimal treatment effect.

Randomized, Evaluator-Blinded Study Comparing Safety and Effect of Two Hyaluronic Acid Gels for Lips Enhancement

PubMed Central

Sattler, Gerhard; Berg, Anna-Karin; Samuelson, Ulf; Wong, Cindy

2018-01-01

BACKGROUND Hyaluronic acid (HA) fillers may differ in terms of gel characteristics and ease of use and it is of interest whether this might affect safety and duration of effect. OBJECTIVE To compare the long-term safety and effect of 2 HA fillers produced by 2 different technologies for lip enhancement. MATERIALS AND METHODS Subjects with very thin to moderately thick lips were randomized and treated with HA-RK (N = 31) or HA-JV (N = 29) to improve lip fullness by ≥ 1 grade on a 5-point scale, using a maximum of 3 mL of product. RESULTS A smaller volume of HA-RK compared with HA-JV was required to improve lip fullness by ≥ 1 grade (mean: 1.54 mL vs 1.94 mL, p < .001). Despite the smaller volume, lip fullness and global aesthetic improvement were comparably sustained in both groups. At 6 months, 60.0% versus 57.7% of subjects (HA-RK vs HA-JV) had improved lip fullness. At 12 months, 71.4% versus 76.0% had aesthetic improvement (blinded evaluations) and 85.7% versus 86.2% felt more attractive. Both products were well tolerated. CONCLUSION Both products achieved durable improvement in lip fullness and aesthetic appearance. A significantly smaller amount of HA-RK was required compared with HA-JV to achieve optimal treatment effect. PMID:29059146

Application of Hydrogel in Reconstruction Surgery: Hydrogel/Fat Graft Complex Filler for Volume Reconstruction in Critical Sized Muscle Defects.

PubMed

Lui, Y F; Ip, W Y

2016-01-01

Autogenic fat graft usually suffers from degeneration and volume shrinkage in volume reconstruction applications. How to maintain graft viability and graft volume is an essential consideration in reconstruction therapies. In this presented investigation, a new fat graft transplantation method was developed aiming to improve long term graft viability and volume reconstruction effect by incorporation of hydrogel. The harvested fat graft is dissociated into small fragments and incorporated into a collagen based hydrogel to form a hydrogel/fat graft complex for volume reconstruction purpose. In vitro results indicate that the collagen based hydrogel can significantly improve the survivability of cells inside isolated graft. In a 6-month investigation on artificial created defect model, this hydrogel/fat graft complex filler has demonstrated the ability of promoting fat pad formation inside the targeted defect area. The newly generated fat pad can cover the whole defect and restore its original dimension in 6-month time point. Compared to simple fat transplantation, this hydrogel/fat graft complex system provides much improvement on long term volume restoration effect against degeneration and volume shrinkage. One notable effect is that there is continuous proliferation of adipose tissue throughout the 6-month period. In summary, the hydrogel/fat graft system presented in this investigation demonstrated a better and more significant effect on volume reconstruction in large sized volume defect than simple fat transplantation.

Wrinkle Fillers

MedlinePlus

... A sore at the injection site Allergic reaction Necrosis (tissue death) The following rare side effects have ... injection, and do not inject dermal fillers into blood vessels in the face. Before injection, thoroughly inform the ...

High-Temperature Insulating Gap Filler

NASA Technical Reports Server (NTRS)

Toombs, Gordon R.; Oyoung, Kevin K.; Stevens, Everett G.

1991-01-01

New inorganic, ceramic filler for gaps between refractory ceramic tiles offers high resistance to heat and erosion. Consists of ceramic-fiber fabric precoated with silica and further coated with silica containing small amount of silicon carbide powder to increase thermal emittance. Developed as replacement for organic filler used on thermal-protection system of Space Shuttle. Promises to serve for many missions and to reduce cost and delay of refurbishing aerospace craft. Used as sealing material in furnaces or as heat shield for sensitive components in automobiles, aircraft, and home appliances.

Friction stir welding and processing of oxide dispersion strengthened (ODS) alloys

DOEpatents

Ren, Weiju

2014-11-11

A method of welding including forming a filler material of a first oxide dispersoid metal, the first oxide dispersoid material having first strengthening particles that compensate for decreases in weld strength of friction stir welded oxide dispersoid metals; positioning the filler material between a first metal structure and a second metal structure each being comprised of at least a second oxide dispersoid metal; and friction welding the filler material, the first metal structure and the second metal structure to provide a weld.

Ocular Pain and Impending Blindness During Facial Cosmetic Injections: Is Your Office Prepared?

PubMed

Prado, Giselle; Rodríguez-Feliz, Jose

2017-02-01

Soft tissue filler injections are the second most common non-surgical procedure performed by the plastic surgeon. Embolization of intravascular material after facial injection is a rare but terrifying outcome due to the high likelihood of long-term sequela such as blindness and cerebrovascular accident. The literature is replete with examples of permanent blindness caused by injection with autologous fat, soft tissue fillers such as hyaluronic acid, PLLA, calcium hydroxyl-apatite, and even corticosteroid suspensions. However, missing from the discussion is an effective treatment algorithm that can be quickly and safely followed by injecting physicians in the case of an intravascular injection with impending blindness. In this report, we present the case of a 64-year-old woman who suffered from blindness and hemiparesis after facial cosmetic injections performed by a family physician. We use this case to create awareness that this complication has become more common as the number of injectors and patients seeking these treatments have increased exponentially over the past few years. We share in this study our experience with the incorporation of a "blindness safety kit" in each of our offices to promptly initiate treatment in someone with embolization and impending blindness. The kit contains a step-by-step protocol to follow in the event of arterial embolization of filler material associated with ocular pain and impending loss of vision. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .