Self-compacting concrete with sugarcane bagasse ash – ground blast furnace slag blended cement: fresh properties

NASA Astrophysics Data System (ADS)

Le, Duc-Hien; Sheen, Yeong-Nain; Ngoc-Tra Lam, My

2018-04-01

In this investigation, major properties in fresh state of self-compacting concrete (SCC) developed from sugarcane bagasse ash and granulated blast furnace slag as supplementary cementitious materials were examined through an experimental work. There were four mix groups (S0, BA10, BA20, and BA30) containing different cement replacing levels; and totally, 12 SCC mixtures and one control mixture were provided for the test. Fresh properties of the proposed SCC were evaluated through measurement of the density, slump, slump-flow, V-funnel test, T500 slump, Box-test, and setting time. The testing results indicated that replacing either SBA and/or BFS to OPC in SCC mixtures led to lower density, lesser flowability, and longer hardening times.

Mechanical and thermal properties of bacterial-cellulose-fibre-reinforced Mater-Bi(®) bionanocomposite.

PubMed

Nainggolan, Hamonangan; Gea, Saharman; Bilotti, Emiliano; Peijs, Ton; Hutagalung, Sabar D

2013-01-01

The effects of the addition of fibres of bacterial cellulose (FBC) to commercial starch of Mater-Bi(®) have been investigated. FBC produced by cultivating Acetobacter xylinum for 21 days in glucose-based medium were purified by sodium hydroxide 2.5 wt % and sodium hypochlorite 2.5 wt % overnight, consecutively. To obtain water-free BC nanofibres, the pellicles were freeze dried at a pressure of 130 mbar at a cooling rate of 10 °C min(-1). Both Mater-Bi and FBC were blended by using a mini twin-screw extruder at 160 °C for 10 min at a rotor speed of 50 rpm. Tensile tests were performed according to ASTM D638 to measure the Young's modulus, tensile strength and elongation at break. A field emission scanning electron microscope was used to observe the morphology at an accelerating voltage of 10 kV. The crystallinity (T c) and melting temperature (T m) were measured by DSC. Results showed a significant improvement in mechanical and thermal properties in accordance with the addition of FBC into Mater-Bi. FBC is easily incorporated in Mater-Bi matrix and produces homogeneous Mater-Bi/FBC composite. The crystallinity of the Mater-Bi/FBC composites decrease in relation to the increase in the volume fraction of FBC.

Physicochemical properties and characterization of chitosan synthesized from fish scales, crab and shrimp shells.

PubMed

Kumari, Suneeta; Kumar Annamareddy, Sri Hari; Abanti, Sahoo; Kumar Rath, Pradip

2017-11-01

Chitosan is derived from different starting materials such as fish scales, shrimp and crab shells by the process of deacetylation of chitin, which is carried out using 40% KOH at 90°C for 6h. Prepared chitosan was characterized by Fourier transforms infrared spectroscopy, X-ray powder diffraction, Scanning electron microscope and Thermogravimetric analysis. Futher the physicochemical properties of chitosan like Fat binding capacity (FBC), water binding capacity (WBC), solubility, average molecular weight, ash content, moisture and degree of deacetylation of chitosan were also studied. Crystalline index (%) values of commercial, shrimp, crab and fish chitosan were found to be 96, 82, 88 and 84% respectively. The presence of amino group was confirmed from the FTIR spectra of chitosan synthesized. TGA results demonstrated the lower thermal stability of chitosan. Relatively smother surface and nano-fiber structures were observed from SEM analysis. The degree of deacetylation of chitosan from different sources such as shells of fish, shrimp and crab were found to be 75%, 78%, and 70% respectively. In a similar way the WBC and FBC of fish, shrimp and crab shells were found to be 492, 358 and 138% and 226, 246 and 138% respectively. Copyright © 2017 Elsevier B.V. All rights reserved.

Men and women show similar survival outcome in stage IV breast cancer.

PubMed

Wu, San-Gang; Zhang, Wen-Wen; Liao, Xu-Lin; Sun, Jia-Yuan; Li, Feng-Yan; Su, Jing-Jun; He, Zhen-Yu

2017-08-01

To evaluate the clinicopathological features, patterns of distant metastases, and survival outcome between stage IV male breast cancer (MBC) and female breast cancer (FBC). Patients diagnosed with stage IV MBC and FBC between 2010 and 2013 were included using the Surveillance, Epidemiology, and End Results program. Univariate and multivariate Cox regression analyses were used to analyze risk factors for overall survival (OS). A total of 4997 patients were identified, including 60 MBC and 4937 FBC. Compared with FBC, patients with MBC were associated with a significantly higher rate of estrogen receptor-positive, progesterone receptor-positive, unmarried, lung metastases, and a lower frequency of liver metastases. Univariate and multivariate analyses showed no significant difference in OS between MBC and FBC. In the propensity score-matched population, there was also no difference in survival between MBC and FBC. Multivariate analysis of MBC showed that OS was longer for patients aged 50-69 years and with estrogen receptor-positive disease. There was no significant difference in survival outcome between stage IV MBC and FBC, but significant differences in clinicopathological features and patterns of metastases between the genders. Copyright © 2017 Elsevier Ltd. All rights reserved.

Predicting the ash behavior during biomass combustion in FBC conditions by combining advanced fuel analyses with thermodynamic multicomponent equilibrium calculations

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

Skrifvars, B.J.; Blomquist, J.P.; Hupa, M.

1998-12-31

Previous work at Aabo Akademi University has focused on identification and quantification of various sintering mechanisms which are relevant for problematic ash behavior during biomass combustion in fluidized bed combustion conditions, and on multi-component multi-phase thermodynamic phase equilibrium calculations of ash chemistry in these conditions. In both areas new information has been developed and useful modeling capabilities have been created. Based on the previous work, the authors now present a novel approach of using a combination of an advanced fuel analysis method and thermodynamic phase equilibrium calculations to predict the chemical and thermal behavior of the ash when firing biomass.more » Four different fuels [coal, forest residues, wood chips, and a mixture of forest residue and wood chips] were analyzed using the chemical fractionation analysis technique. Based on the results from these analyses, the authors formed two different ash fractions, (1) one fine sized fraction consisting of those elements found in the water and weak acid leach, and (2) a coarse ash particle fraction consisting of those elements found in the strong acid leach and non-leachable rest. The small sized ash fraction was then assumed to be carried up with the flue gases and consequently formed the base for any ash related problems in the flue gas channel. This fraction was therefore analyzed on its chemical and thermal behavior using multi-component multi-phase equilibrium calculations, by which the composition and the melting behavior was estimated as a function of the temperature. The amount of melt, which has earlier been found to be strongly related to problematic ash behavior, was finally expressed as a function of the temperature for the fraction. The coarse fraction was treated separately. Here the authors estimate the composition only. The paper discusses the results and their relevance to full scale combustion.« less

PARTICULATE EMISSIONS AND CONTROL IN FLUIDIZED-BED COMBUSTION: MODELING AND PARAMETRIC PERFORMANCE

EPA Science Inventory

The report discusses a model, developed to describe the physical characteristics of the particulates emitted from fluidized-bed combustion (FBC) systems and to evaluate data on FBC particulate control systems. The model, which describes the particulate emissions profile from FBC,...

Elevation of transforming growth factor beta (TGFbeta) and its downstream mediators in subcutaneous foreign body capsule tissue.

PubMed

Li, Allen G; Quinn, Matthew J; Siddiqui, Yasmin; Wood, Michael D; Federiuk, Isaac F; Duman, Heather M; Ward, W Kenneth

2007-08-01

Foreign body encapsulation represents a chronic fibrotic response and has been a major obstacle that reduces the useful life of implanted biomedical devices. The precise mechanism underlying such an encapsulation is still unknown. We hypothesized that, considering its central role in many other fibrotic conditions, transforming growth factor beta (TGFbeta) may play an important role during the formation of foreign body capsule (FBC). In the present study, we implanted mock sensors in rats subcutaneously and excised FBC samples at day 7, 21, and 48-55 postimplantation. The most abundant TGFbeta isoform in all tissues was TGFbeta1, which was expressed minimally in control tissue. The expression of both TGFbeta1 RNA and protein was significantly increased in FBC tissues at all time points, with the highest level in day 7 FBC. The number of cells stained for phosphorylated Smad2, an indication of activated TGFbeta signaling, paralleled the expression of TGFbeta. A similar dynamic change was also observed in the numbers of FBC myofibroblasts, which in response to TGFbeta, differentiate from quiescent fibroblasts and synthesize collagen. Type I collagen, the most prominent downstream target of TGFbeta in fibrosis, was found in abundance in the FBC, especially during the latter time periods. We suggest that TGFbeta plays an important role in the FBC formation. Inhibition of TGFbeta signaling could be a promising strategy in the prevention of FBC formation, thereby extending the useful life of subcutaneous implants.

Simulation of fluidized bed combustors. I - Combustion efficiency and temperature profile. [for coal-fired gas turbines

NASA Technical Reports Server (NTRS)

Horio, M.; Wen, C. Y.

1976-01-01

A chemical engineering analysis is made of fluidized-bed combustor (FBC) performance, with FBC models developed to aid estimation of combustion efficiency and axial temperature profiles. The FBC is intended for combustion of pulverized coal and a pressurized FBC version is intended for firing gas turbines by burning coal. Transport phenomena are analyzed at length: circulation, mixing models, drifting, bubble wake lift, heat transfer, division of the FB reactor into idealized mixing cells. Some disadvantages of a coal FBC are pointed out: erosion of immersed heat-transfer tubing, complex feed systems, carryover of unburned coal particles, high particulate emission in off-streams. The low-temperature bed (800-950 C) contains limestone, and flue-gas-entrained SO2 and NOx can be kept within acceptable limits.

Survival benefit of tamoxifen and aromatase inhibitor in male and female breast cancer.

PubMed

Eggemann, Holm; Altmann, Udo; Costa, Serban-Dan; Ignatov, Atanas

2018-02-01

Our goal was to compare the survival advantage of tamoxifen (TAM) and aromatase inhibitor (AI) in female (FBC) and male breast cancer (MBC). We performed a retrospective study of 2785 FBC and 257 MBC patients treated with hormonal therapy. The median follow-up was 106 months (range 3-151 months) and 42 months (range 2-115 months) for FBC and MBC, respectively. The patients were divided into two groups according to the hormonal therapy used: TAM-treated and AI-treated. MBC was characterized by older age, advanced tumor stage, and higher rate of lymph node metastases, in comparison with FBC. Matching analysis was performed using six prognostic criteria: patient age, tumor stage, tumor grade, lymph node status, human epidermal growth factor receptor (HER2) status, and administration of chemotherapy. The female and male patients were matched 2:1. In this analysis, 316 women and 158 men treated with TAM, and 60 women and 30 men treated with AI, were included. The overall survival (OS) was estimated by the Kaplan-Meier method and was compared between FBC and MBC. TAM-treated FBC and MBC patients had similar 5-year OS, 85.1 and 89.2%, respectively (p = 0.972). Notably, FBC patients treated with AI had significantly greater 5-year OS (85.0%) in comparison with AI-treated MBC patients (5-year OS of 73.3%; p = 0.028). The OS of TAM-treated patients with MBC was similar to the OS of TAM-treated FBC patients, whereas AI treatment is associated with poorer survival of MBC patients.

Effect of estrogen on morphine- and oxycodone-induced antinociception in a female femur bone cancer pain model.

PubMed

Ono, Hiroko; Nakamura, Atsushi; Kanemasa, Toshiyuki; Sakaguchi, Gaku; Shinohara, Shunji

2016-02-15

Although estrous cycle has been reported to influence antiociceptive effect of morphine in several pain conditions, its effect on cancer pain is not well established. We investigated the effect of estrogen on morphine antinociception using a bone cancer pain model and compared its potency with that of oxycodone. Female mice were ovariectomized (OVX) for preparation of a femur bone cancer pain (FBC) model. β-estradiol was subcutaneously (s.c.) administered and antinociceptive effects of opioids was assessed using the von Frey monofilament test. Although morphine (5-20mg/kg, s.c.) did have significant antinociceptive effects in the FBC-OVX group, its effects in the FBC-OVX+β-estradiol (OVX+E) group was limited. Oxycodone (1-5mg/kg, s.c.) exhibited significant effects in both groups. Expression changes in opioid-related genes (μ-, κ-, δ-opioid receptors, prodynorphin, proenkephalin, proopiomelanocortin) in the spinal and supraspinal sites were examined among the sham-OVX, sham-OVX+E, FBC-OVX, and FBC-OVX+E groups by in situ hybridization. These studies detected a significant increase in prodynorphin in the spinal dorsal horn of the FBC-OVX+E group. Spinal injection of a dynorphin-A antibody to FBC-OVX+E mice restored antinociception of morphine. In conclusion, we detected a differential effect of estrogen on morphine- and oxycodone-induced antinociception in a female FBC model. The effect of morphine was limited with estrogen exposure, which may be due to estrogen- and pain-mediated spinal expression of dynorphin-A. Copyright © 2016 Elsevier B.V. All rights reserved.

Cost effectiveness of facility-based care, home-based care and mobile clinics for provision of antiretroviral therapy in Uganda.

PubMed

Babigumira, Joseph B; Sethi, Ajay K; Smyth, Kathleen A; Singer, Mendel E

2009-01-01

Stakeholders in HIV/AIDS care currently use different programmes for provision of antiretroviral therapy (ART) in Uganda. It is not known which of these represents the best value for money. To compare the cost effectiveness of home-based care (HBC), facility-based care (FBC) and mobile clinic care (MCC) for provision of ART in Uganda. Incremental cost-effectiveness analysis was performed using decision and Markov modeling of adult AIDS patients in WHO Clinical Stage 3 and 4 from the perspective of the Ugandan healthcare system. The main outcome measures were cost (year 2008 values), life expectancy in life-years (LY) and the incremental cost-effectiveness ratio (ICER) measured as cost per QALY or LY gained over 10 years. Ten-year mean undiscounted life expectancy was lowest for FBC (3.6 LY), followed by MCC (4.3 LY) and highest for HBC (5.3 LY), while the mean discounted QALYs were also lowest for FBC (2.3), followed by MCC (2.9) and highest for HBC (3.7). The 10-year mean costs per patient were lowest for FBC ($US3212), followed by MCC ($US4782) and highest for HBC ($US7033). The ICER was lower for MCC versus FBC ($US2241 per LY and $US2615 per QALY) than for HBC versus MCC ($US2251 per LY and $US2814 per QALY). FBC remained cost effective in univariate and probabilistic sensitivity analyses. FBC appears to be the most cost-effective programme for provision of ART in Uganda. This analysis supports the implementation of FBC for scale-up and sustainability of ART in Uganda. HBC and MCC would be competitive only if there is increased access, increased adherence or reduced cost.

Forward Bay Cover Separation Modeling and Testing for the Orion Multi-Purpose Crew Vehicle

NASA Technical Reports Server (NTRS)

Ali, Yasmin; Chuhta, Jesse D.; Hughes, Michael P.; Radke, Tara S.

2015-01-01

Spacecraft multi-body separation events during atmospheric descent require complex testing and analysis to validate the flight separation dynamics models used to verify no re-contact. The NASA Orion Multi-Purpose Crew Vehicle (MPCV) architecture includes a highly-integrated Forward Bay Cover (FBC) jettison assembly design that combines parachutes and piston thrusters to separate the FBC from the Crew Module (CM) and avoid re-contact. A multi-disciplinary team across numerous organizations examined key model parameters and risk areas to develop a robust but affordable test campaign in order to validate and verify the FBC separation event for Exploration Flight Test-1 (EFT-1). The FBC jettison simulation model is highly complex, consisting of dozens of parameters varied simultaneously, with numerous multi-parameter interactions (coupling and feedback) among the various model elements, and encompassing distinct near-field, mid-field, and far-field regimes. The test campaign was composed of component-level testing (for example gas-piston thrusters and parachute mortars), ground FBC jettison tests, and FBC jettison air-drop tests that were accomplished by a highly multi-disciplinary team. Three ground jettison tests isolated the testing of mechanisms and structures to anchor the simulation models excluding aerodynamic effects. Subsequently, two air-drop tests added aerodynamic and parachute elements, and served as integrated system demonstrations, which had been preliminarily explored during the Orion Pad Abort-1 (PA-1) flight test in May 2010. Both ground and drop tests provided extensive data to validate analytical models and to verify the FBC jettison event for EFT-1. Additional testing will be required to support human certification of this separation event, for which NASA and Lockheed Martin are applying knowledge from Apollo and EFT-1 testing and modeling to develop a robust human-rated FBC separation event.

Cost Effectiveness of Facility-Based Care, Home-Based Care and Mobile Clinics for Provision of Antiretroviral Therapy in Uganda

PubMed Central

Babigumira, Joseph B.; Sethi, Ajay K.; Smyth, Kathleen A.; Singer, Mendel E.

2012-01-01

Background Stakeholders in HIV/AIDS care currently use different programmes for provision of antiretroviral therapy (ART) in Uganda. It is not known which of these represents the best value for money. Objective To compare the cost effectiveness of home-based care (HBC), facility-based care (FBC) and mobile clinic care (MCC) for provision of ART in Uganda. Methods Incremental cost-effectiveness analysis was performed using decision and Markov modeling of adult AIDS patients in WHO Clinical Stage 3 and 4 from the perspective of the Ugandan healthcare system. The main outcome measures were cost (year 2008 values), life expectancy in life-years (LY) and the incremental cost-effectiveness ratio (ICER) measured as cost per QALY or LY gained over 10 years. Results Ten-year mean undiscounted life expectancy was lowest for FBC (3.6 LY), followed by MCC (4.3 LY) and highest for HBC (5.3 LY), while the mean discounted QALYs were also lowest for FBC (2.3), followed by MCC (2.9) and highest for HBC (3.7). The 10-year mean costs per patient were lowest for FBC ($US3212), followed by MCC ($US4782) and highest for HBC ($US7033). The ICER was lower for MCC versus FBC ($US2241 per LY and $US2615 per QALY) than for HBC versus MCC ($US2251 per LY and $US2814 per QALY). FBC remained cost effective in univariate and probabilistic sensitivity analyses. Conclusions FBC appears to be the most cost-effective programme for provision of ART in Uganda. This analysis supports the implementation of FBC for scale-up and sustainability of ART in Uganda. HBC and MCC would be competitive only if there is increased access, increased adherence or reduced cost. PMID:19888795

Examining the Associations among Fibrocystic Breast Change, Total Lean Mass, and Percent Body Fat.

PubMed

Chen, Yuan-Yuei; Fang, Wen-Hui; Wang, Chung-Ching; Kao, Tung-Wei; Chang, Yaw-Wen; Yang, Hui-Fang; Wu, Chen-Jung; Sun, Yu-Shan; Chen, Wei-Liang

2018-06-15

Fibrocystic breast change (FBC) is extremely common and occurrs in 90% of women during their lives. The association between body composition and risk of breast cancer is well established. We hypothesized that the effect might exist during the development of FBC. Our aim was to examine the relationships of total lean mass (TLM) and percent body fat (PBF) with FBC in a general female population. In total, 8477 female subjects aged 20 years or older were enrolled in the study at the Tri-Service General Hospital in Taiwan from 2011 to 2016. Comprehensive examinations including biochemical data, measurements of body composition and breast ultrasound were performed. PBF was positively associated with the presence of FBC (OR = 1.039, 95%CI: 1.018-1.060), and TLM showed the opposite result (OR = 0.893, 95%CI: 0.861-0.926). Condition of metabolic syndrome (MetS), diabetes (DM) and fatty liver modified the association between PBF and FBC (P < 0.001, P = 0.032 and P = 0.007, respectively). Female subjects diagnosed with MetS, DM, and fatty liver had higher risk of developing FBC than control subjects (OR = 1.110, 95%CI: 1.052-1.171; OR = 1.144, 95%CI: 1.024-1.278; OR = 1.049, 95%CI: 1.019, 1.080). Those with higher PBF (for highest quartile versus lowest, OR = 2.451, 95%CI: 1.523-3.944) or lower TLM (for highest quartile versus lowest, OR = 0.279, 95%CI: 0.171-0.455) had increased risk of developing FBC. In conclusion, increased PBF and reduced TLM were likely to predict the risk of the presence of FBC in a general female population.

Meat and bone meal as secondary fuel in fluidized bed combustion

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

L. Fryda; K. Panopoulos; P. Vourliotis

2007-07-01

Meat and Bone Meal (MBM) was co-fired in a laboratory scale fluidized bed combustion (FBC) apparatus with two coals. Several fuel blends were combusted under different conditions to study how primary fuel substitution by MBM affects flue gas emissions as well as fluidized bed (FB) agglomeration tendency. MBM, being a highly volatile fuel, caused significant increase of CO emissions and secondary air should be used in industrial scale applications to conform to regulations. The high N-content of MBM is moderately reflected on the increase of nitrogen oxides emissions which are reduced by MBM derived volatiles. The MBM ash, mainly containingmore » bone material rich in Ca, did not create any noteworthy desulphurization effect. The observed slight decrease in SO{sub 2} emissions is predominantly attributed to the lower sulphur content in the coal/MBM fuel mixtures. The SEM/EDS analysis of bed material samples from the coal/MBM tests revealed the formation of agglomerates of bed material debris and ash with sizes that do not greatly exceed the original bed inventory and thus not problematic. 37 refs., 9 figs., 3 tabs.« less

Fluidized bed combustion of pelletized biomass and waste-derived fuels

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

Chirone, R.; Scala, F.; Solimene, R.

2008-10-15

The fluidized bed combustion of three pelletized biogenic fuels (sewage sludge, wood, and straw) has been investigated with a combination of experimental techniques. The fuels have been characterized from the standpoints of patterns and rates of fuel devolatilization and char burnout, extent of attrition and fragmentation, and their relevance to the fuel particle size distribution and the amount and size distribution of primary ash particles. Results highlight differences and similarities among the three fuels tested. The fuels were all characterized by limited primary fragmentation and relatively long devolatilization times, as compared with the time scale of particle dispersion away frommore » the fuel feeding ports in practical FBC. Both features are favorable to effective lateral distribution of volatile matter across the combustor cross section. The three fuels exhibited distinctively different char conversion patterns. The high-ash pelletized sludge burned according to the shrinking core conversion pattern with negligible occurrence of secondary fragmentation. The low-ash pelletized wood burned according to the shrinking particle conversion pattern with extensive occurrence of secondary fragmentation. The medium-ash pelletized straw yielded char particles with a hollow structure, resembling big cenospheres, characterized by a coherent inorganic outer layer strong enough to prevent particle fragmentation. Inert bed particles were permanently attached to the hollow pellets as they were incorporated into ash melts. Carbon elutriation rates were very small for all the fuels tested. For pelletized sludge and straw, this was mostly due to the shielding effect of the coherent ash skeleton. For the wood pellet, carbon attrition was extensive, but was largely counterbalanced by effective afterburning due to the large intrinsic reactivity of attrited char fines. The impact of carbon attrition on combustion efficiency was negligible for all the fuels tested. The size distribution of primary ash particles liberated upon complete carbon burnoff largely reflected the combustion pattern of each fuel. Primary ash particles of size nearly equal to that of the parent fuel were generated upon complete burnoff of the pelletized sludge. Nonetheless, secondary attrition of primary ash from pelletized sludge is large, to the point where generation of fine ash would be extensive over the typical residence time of bed ash in fluidized bed combustors. Very few and relatively fine primary ash particles were released after complete burnoff of wood pellets. Primary ash particles remaining after complete burnoff of pelletized straw had sizes and shapes that were largely controlled by the occurrence of ash agglomeration phenomena. (author)« less

[Profitability of the bronchoscopy in the diagnosis of focal pulmonary malignant lesions].

PubMed

García Quero, C; García Luján, R; González Torralba, F; de Miguel Poch, E; Alfaro Abreu, J; Villena Garrido, V; López Ríos, F; López Encuentra, A

2008-12-01

We define focal pulmonary lesion (FPL) as an intra-parenchymatous pulmonary lesion that is well circumscribed and completely surrounded by healthy lung. It is considered that the profitability of the fine needle aspiration puncture (FNAP) in FPL < or = 2 cm is better than that of the fibrobronchoscopy (FBC). To analyze the diagnostic profitability of the FNAP in the malignant FPL and study if it varies according to site, size and histology. We analyzed all the FBCs of our Unit between 01/2000 and 12/2001 in patients with solitary FLP < or = 6 cm with a definitive diagnosis of malignancy. The diagnostic profitability by size, site and histology was analyzed with Pearson's chi(2) statistics. 124 patients. Mean FBC per patient was 1.3. A total of 101 cases (82%) were diagnosed with FBC, 15 by thoracotomy and 8 by FNAP. Global diagnostic profitability of the FBC was 0.82 and the transbronchial biopsy 0.76. There are no diagnostic profitability differences by size (< or = 2 cm vs > 2 cm) (0.81 vs 0.82 p = 0.96), site (peripheral vs central) (0.79 vs 0.85 p = 0.41) and histology (epidermoid vs adenocarcinoma) (0.89 vs 0.75 p = 0.21). Profitability of the FBC in malignant FPL in our hospital is elevated without differences by size, site or histology. In our site, the initial diagnostic approach of the FLP is done with FBC.

Changes in glutamate concentration, glucose metabolism, and cerebral blood flow during focal brain cooling of the epileptogenic cortex in humans.

PubMed

Nomura, Sadahiro; Fujii, Masami; Inoue, Takao; He, Yeting; Maruta, Yuichi; Koizumi, Hiroyasu; Suehiro, Eiichi; Imoto, Hirochika; Ishihara, Hideyuki; Oka, Fumiaki; Matsumoto, Mishiya; Owada, Yuji; Yamakawa, Takeshi; Suzuki, Michiyasu

2014-05-01

Recently, focal brain cooling (FBC) was proposed as a method for treating refractory epilepsy. However, the precise influence of cooling on the molecular basis of epilepsy has not been elucidated. Thus the aim of this study was to assess the effect of FBC on glutamate (Glu) concentration, cerebral blood flow (CBF), and glucose metabolism in patients with intractable epilepsy. Nine patients underwent FBC at 15°C for 30 min prior to cortical resection (n = 6) or hippocampectomy (n = 3). Measurement of metabolites and CBF, as well as electrocorticography (ECoG), was performed. Epileptic discharge (ED), as observed by ECoG, disappeared in the cooling period and reappeared in the rewarming period. Glu concentrations were high during the precooling period and were reduced to 51.2% during the cooling period (p = 0.025). Glycerol levels showed a similar decrease (p = 0.028). Lactate concentration was high during the precooling period and was reduced during the cooling period (21.3% decrease; p = 0.005). Glucose and pyruvate levels were maintained throughout the procedure. Changes in CBF were parallel to those observed by ECoG. FBC reduced EDs and concentrations of Glu and glycerol. This demonstrates the neuroprotective effect of FBC. Our findings confirm that FBC is a reasonable and optimal treatment option for patients with intractable epilepsy. Wiley Periodicals, Inc. © 2014 International League Against Epilepsy.

First birth cesarean proportion: A missed indicator in controlling policies

PubMed Central

Safari-Faramani, Roya; Haghdoost, Ali Akbar; Nakhaei, Nouzar; Foroudnia, Shohreh; Mahmoodabadi, Zahra; Safizadeh, Mansooreh

2016-01-01

Background: Around one out of two mothers give births by cesarean section (CS) surgery in Iran and about half of this number is due to previous CS. Recently Health Sector Evolution (HSEP) program (started in April 2014) targets the high rate of CS in Iran. To assess the impact of the interventions, we emphasized that the First Birth Cesarean (FBC) proportion is one of the main indicators to assess the controlling programs. Methods: Data on the mode of delivery were collected in Kerman province between 21 March and 20 March 2015 classified by hospital ownership. FBC proportion is defined as the number of CS in the first pregnancies divided by the total number of first births. Chi-square test for trend was used to assess the trends. Results: Total number of births was around 34000. There were 8.9 and 13.1 percent reduction in CS and FBC proportion respectively. CS proportion was 54.5 at the end of the first quarter of the studied period and reached to 49.6 at the end of the period (p<0.0001). Also, FBC proportion was 54.1 percent at first and reached to 47 percent at the end of the study period. The main reason for CS was due to previous CS. At the hospital level, the highest reduction in CS and FBC proportion were in public hospitals. Conclusion: Results suggested more reduction in FBC proportion than the CS proportion, so this is a very good sign since more potential CS cases will be prevented. As repeated CS is one of the main indications for the operation, in the short term, even effective policies may change the overall proportion slightly, while the FBC proportion is more sensitive to reflect the impacts. Therefore, it is necessary to target the main fuel to reduce CS proportion effectively. PMID:27579285

Coprescription of Chinese herbal medicine and Western medication among female patients with breast cancer in Taiwan: analysis of national insurance claims.

PubMed

Wang, Bih-Ru; Chang, Yuh-Lih; Chen, Tzeng-Ji; Chiu, Jen-Hwey; Wu, Jing Chong; Wu, Min-Shan; Chou, Chia-Lin; Chou, Yueh-Ching

2014-01-01

Many female breast cancer (FBC) patients take Chinese herbal medicine (CHM) and Western medication (WM) concurrently in Taiwan. Despite the possibility of interactions between the CHM and WM mentioned in previous studies, the pattern of these coprescriptions in FBC patients remains unclear. Hence, the aim of the present study is to investigate the utilization of coprescriptions of CHM and WM among the FBC patients in Taiwan. The study was a cross-sectional survey using the sampled cohort in 2009 obtained from the National Health Insurance Research Database in Taiwan. There were 3,507 FBC patients identified from the registry for catastrophic illness patients. Ambulatory visit records, corresponding prescriptions, and the data of beneficiaries belonging to the FBC patients were further extracted. A total of 1,086 FBC patients used CHM at least once. CHM and WM prescribed within any overlapping duration were defined as coprescriptions. There were 868 (80.0%) patients simultaneously receiving CHM and WM. A total of 4,927 CHM prescriptions and 6,358 WM prescriptions were prescribed concurrently. Among these coprescriptions, the most frequently used CHM was jia-wei-xiao-yao-san (21.2%), and the most frequently coprescribed WM was acetaminophen (38.9%), followed by tamoxifen (25.5%). There were 346 patients using systemic adjuvant therapy and CHM concurrently. The most commonly coprescribed CHM with chemotherapy, endocrine therapy, and trastuzumab was xiang-sha-liu-jun-zi-tang, jia-wei-xiao-yao-san, and zhi-gan-cao-tang, respectively. The combined use of CHM with WM is prevalent. The main purpose of combining CHM with systemic cancer treatment is to alleviate the treatment-related adverse effects. However, the combination may result in the potential risk of drug-herb interactions. Further clinical studies are needed to evaluate the efficacy and safety of the CHM and WM coprescriptions for FBC patients.

The effect of microgeometry, implant thickness and polyurethane chemistry on the foreign body response to subcutaneous implants.

PubMed

Ward, W Kenneth; Slobodzian, Emily P; Tiekotter, Kenneth L; Wood, Michael D

2002-11-01

We addressed the effect of implant thickness, implant porosity, and polyurethane (PU) chemistry on angiogenesis and on the foreign body response in rats. The following materials were implanted subcutaneously for 7 weeks then excised for histologic analysis: a solid PU; a solid polyurethane with silicone and polyethylene oxide (PU-S-PEO); porous expanded polytetrafluoroethylene (ePTFE); and porous polyvinyl alcohol sponge (PVA). Two thicknesses of PU-S-PEO were compared: 300 microns (thin) and 2000 microns (thick). Foreign body capsule (FBC) thickness was much less in PU-S-PEO implants than in PU implants. In addition, FBC were thinner in thin implants than in thick implants. FBC was much more dense in solid implants than in porous implants. As compared with solid implants, porous implants (PVA and ePTFE) led to a marked increase in the number of microvessels that developed adjacent to the implant, as observed both with hematoxylin/eosin staining and with an immunohistochemical anti-endothelial stain. We conclude that the polyethylene oxide and silicone moieties in PU reduce the thickness of the subsequent FBC. In addition, thin implants lead to a thin FBC. Porous implants (PVA and ePTFE) cause more angiogenesis than solid implants. These results may have implications for the measurement of blood-derived analytes by biosensors.

Online self-test identifies women at high familial breast cancer risk in population-based breast cancer screening without inducing anxiety or distress.

PubMed

van Erkelens, A; Sie, A S; Manders, P; Visser, A; Duijm, L E; Mann, R M; Ten Voorde, M; Kroeze, H; Prins, J B; Hoogerbrugge, N

2017-06-01

Identifying high familial breast cancer (FBC) risk improves detection of yet unknown BRCA1/2-mutation carriers, for whom BC risk is both highly likely and potentially preventable. We assessed whether a new online self-test could identify women at high FBC risk in population-based BC screening without inducing anxiety or distress. After their visit for screening mammography, women were invited by email to take an online self-test for identifying highly increased FBC risk-based on Dutch guidelines. Exclusion criteria were previously diagnosed as increased FBC risk or a personal history of BC. Anxiety (State-Trait Anxiety Inventory Dutch Version), distress (Hospital Anxiety Depression Scale) and BC risk perception were assessed using questionnaires, which were completed immediately before and after taking the online self-test and 2 weeks later. Of the 562 women invited by email, 406 (72%) completed the online self-test while 304 also completed questionnaires (response rate 54%). After exclusion criteria, 287 (51%) were included for data analysis. Median age was 56 years (range 50-74). A high or moderate FBC risk was identified in 12 (4%) and three (1%) women, respectively. After completion of the online self-test, anxiety and BC risk perception were decreased while distress scores remained unchanged. Levels were below clinical relevance. Most women (85%) would recommend the self-test; few (3%) would not. The online self-test identified previously unknown women at high FBC risk (4%), who may carry a BRCA1/2-mutation, without inducing anxiety or distress. We therefore recommend offering this self-test to women who attend population-based screening mammography for the first time. Copyright © 2017 Elsevier Ltd. All rights reserved.

Expression of connective tissue growth factor in male breast cancer: clinicopathologic correlations and prognostic value.

PubMed

Lacle, Miangela M; van Diest, Paul J; Goldschmeding, Roel; van der Wall, Elsken; Nguyen, Tri Q

2015-01-01

Connective tissue growth factor (CTGF/CCN2) is a member of the CCN family of secreted proteins that are believed to play an important role in the development of neoplasia. In particular, CTGF has been reported to play an important role in mammary tumorigenesis and to have prognostic value in female breast cancer (FBC). The aim of the present study was to investigate clinicopathologic correlations and prognostic value of CTGF in male breast cancer (MBC) and to compare these findings with FBC. For this, we studied CTGF protein expression by immunohistochemistry in 109 MBC cases and 75 FBC cases. In MBC, stromal CTGF expression was seen in the majority of the cases 78% (85/109) with high expression in 31/109 cases (28.4%), but expression in tumor cells was only seen in 9.2% (10/109) of cases. High stromal CTGF expression correlated with high grade and high proliferation index (>15%) assessed by MIB-1 immunohistochemical staining. CTGF expression in tumor epithelial cells did not correlate with any of the clinicopathologic features. In FBC, stromal CTGF expression positively correlated with mitotic count and tumor CTGF expression was associated with triple negative status of the tumor (p = 0.002). Neither stromal nor tumor epithelial cell CTGF expression had prognostic value in MBC and FBC. In conclusion, stromal CTGF expression was seen in a high percentage of MBC and was correlated with high grade and high proliferation index. In view of the important role of the microenvironment in cancer progression, this might suggest that stromal CTGF could be an interesting target for novel therapies and molecular imaging. However, the lack of association with prognosis warrants caution. The potential role of CTGF as a therapeutic target for triple negative FBC deserves to be further studied.

Sequential capture of CO2 and SO2 in a pressurized TGA simulating FBC conditions.

PubMed

Sun, Ping; Grace, John R; Lim, C Jim; Anthony, Edward J

2007-04-15

Four FBC-based processes were investigated as possible means of sequentially capturing SO2 and CO2. Sorbent performance is the key to their technical feasibility. Two sorbents (a limestone and a dolomite) were tested in a pressurized thermogravimetric analyzer (PTGA). The sorbent behaviors were explained based on complex interaction between carbonation, sulfation, and direct sulfation. The best option involved using limestone or dolomite as a SO2-sorbent in a FBC combustor following cyclic CO2 capture. Highly sintered limestone is a good sorbent for SO2 because of the generation of macropores during calcination/carbonation cycling.

Hybrid feedforward and feedback controller design for nuclear steam generators over wide range operation using genetic algorithm

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

Zhao, Y.; Edwards, R.M.; Lee, K.Y.

1997-03-01

In this paper, a simplified model with a lower order is first developed for a nuclear steam generator system and verified against some realistic environments. Based on this simplified model, a hybrid multi-input and multi-out (MIMO) control system, consisting of feedforward control (FFC) and feedback control (FBC), is designed for wide range conditions by using the genetic algorithm (GA) technique. The FFC control, obtained by the GA optimization method, injects an a priori command input into the system to achieve an optimal performance for the designed system, while the GA-based FBC control provides the necessary compensation for any disturbances ormore » uncertainties in a real steam generator. The FBC control is an optimal design of a PI-based control system which would be more acceptable for industrial practices and power plant control system upgrades. The designed hybrid MIMO FFC/FBC control system is first applied to the simplified model and then to a more complicated model with a higher order which is used as a substitute of the real system to test the efficacy of the designed control system. Results from computer simulations show that the designed GA-based hybrid MIMO FFC/FBC control can achieve good responses and robust performances. Hence, it can be considered as a viable alternative to the current control system upgrade.« less

An overview of metals recovery from thermal power plant solid wastes.

PubMed

Meawad, Amr S; Bojinova, Darinka Y; Pelovski, Yoncho G

2010-12-01

Thermal power plants (TPPs) that burn fossil fuels emit several pollutants linked to the environmental problems of acid rain, urban ozone, and the possibility of global climate change. As coal is burned in a power plant, its noncombustible mineral content is partitioned into bottom ash, which remains in the furnace, and fly ash, which rises with flue gases. Two other by-products of coal combustion air-pollution control technologies are flue gas desulfurization (FGD) wastes and fluidized-bed combustion (FBC) wastes. This paper analyzed and summarized the generation, characteristics and application of TPP solid wastes and discussed the potential effects of such solid wastes on the environment. On this basis, a review of a number of methods for recovery of metals from TPP solid wastes was made. They usually contain a quantity of valuable metals and they are actually a secondary resource of metals. By applying mineral processing technologies and hydrometallurgical and biohydrometallurgical processes, it is possible to recover metals such as Al, Ga, Ge, Ca, Cd, Fe, Hg, Mg, Na, Ni, Pb, Ra, Th, V, Zn, etc., from TPP solid wastes. Recovery of metals from such wastes and its utilization are important not only for saving metal resources, but also for protecting the environment. Copyright © 2010 Elsevier Ltd. All rights reserved.

The effectiveness of stone ash and volcanic ash of mount Sinabung as a filler on the initial strength of self-compacting concrete

NASA Astrophysics Data System (ADS)

Karolina, R.; Muhammad, W.; Saragih, M. D. S. M.; Mustaqa, T.

2018-02-01

Self Compacting Concrete is a concrete variant that has a high degree of workability and also has great initial strength, but low water cement factor. It is also self-flowable that can be molded on formwork with a very little or no compacted use of compactors. This concrete, using a variety of aggregate sizes, aggregate portions and superplasticizer admixture to achieve a special viscosity that allows it to flow on its own without the aid of a compactor. Lightweight concrete brick is a type of brick made from cement, sand, water, and developers. Lightweight concrete bricks are divided into 2 based on the developed materials used are AAC (Autoclave Aerated Concrete) using aluminum paste and CLC (Cellular Lightweight Concrete) that use Foaming Agent from BASF as a developer material. In this experiment, the lightweight bricks that will be made are CLC type which uses Foaming Agent as the developer material by mixing the Ash Stone produced by Stone Crusher machine which has the density of 2666 kg / m3 as Partial Pair Substitution. In this study the variation of Ash Stone used is 10%, 15%, and 20% of the planned amount of sand. After doing the tasting the result is obtained for 10% variation. Compressive Strength and Absorption Increase will decrease by 25.07% and 39.005% and Variation of 15% compressive strength will decrease by 65,8% and decrease of absorbtion equal to 17,441% and variation of 20% compressive strength will decreased by 67,4 and absorption increase equal to 17,956%.

Modulation transfer function assessment in parallel beam and fan beam collimators with square and cylindrical holes.

PubMed

Khorshidi, Abdollah; Ashoor, Mansour

2014-05-01

This study investigates modulation transfer function (MTF) in parallel beam (PB) and fan beam (FB) collimators using the Monte Carlo method with full width at half maximum (FWHM), square and circular-shaped holes, and scatter and penetration (S + P) components. A regulation similar to the lead-to-air ratio was used for both collimators to estimate output data. The hole pattern was designed to compare FB by PB parameters. The radioactive source in air and in a water phantom placed in front of the collimators was simulated using MCNP5 code. The test results indicated that the square holes in PB (PBs) had better FWHM than did the cylindrical (PBc) holes. In contrast, the cylindrical holes in the FB (FBc) had better FWHM than the square holes. In general, the resolution of FBc was better than that of the PBc in air and scatter mediums. The S + P decreased for all collimators as the distance from the source to the collimator surface (z) increased. The FBc had a lower S + P than FBs, but PBc had a higher S + P than PBs. Of the FB and PB collimators with the identical hole shapes, PBs had a smaller S + P than FBs, and FBc had a smaller S + P than PBc. The MTF value for the FB was greater than for the PB and had increased spatial frequency; the FBc had higher MTF than the FBs and PB collimators. Estimating the FB using PB parameters and diverse hole shapes may be useful in collimator design to improve the resolution and efficiency of SPECT images.

Forward Bay Cover Separation Modeling and Testing for the Orion Multi-Purpose Crew Vehicle

NASA Technical Reports Server (NTRS)

Ali, Yasmin; Radke, Tara; Chuhta, Jesse; Hughes, Michael

2014-01-01

Spacecraft multi-body separation events during atmospheric descent require complex testing and analysis to validate the flight separation dynamics model and to verify no recontact. NASA Orion Multi-Purpose Crew Vehicle (MPCV) teams examined key model parameters and risk areas to develop a robust but affordable test campaign in order to validate and verify the Forward Bay Cover (FBC) separation event for Exploration Flight Test-1 (EFT-1). The FBC jettison simulation model is highly complex, consisting of dozens of parameters varied simultaneously, with numerous multi-parameter interactions (coupling and feedback) among the various model elements, and encompassing distinct near-field, mid-field, and far-field regimes. The test campaign was composed of component-level testing (for example gas-piston thrusters and parachute mortars), ground FBC jettison tests, and FBC jettison air-drop tests that were accomplished by a highly multi-disciplinary team. Three ground jettison tests isolated the testing of mechanisms and structures to anchor the simulation models excluding aerodynamic effects. Subsequently, two air-drop tests added aerodynamic and parachute parameters, and served as integrated system demonstrations, which had been preliminarily explored during the Orion Pad Abort-1 (PA-1) flight test in May 2010. Both ground and drop tests provided extensive data to validate analytical models and to verify the FBC jettison event for EFT-1, but more testing is required to support human certification, for which NASA and Lockheed Martin are applying knowledge from Apollo and EFT-1 testing and modeling to develop a robust but affordable human spacecraft capability.

New toxics, new poverty: a social understanding of the freebase cocaine/Paco in Buenos Aires, Argentina.

PubMed

Epele, María E

2011-01-01

Included within the field of research on changes in drug use patterns and vulnerability are conditions of emergency related to economic crisis, wars, and political conflict. This study addresses the complex connections between the rapid propagation of freebase cocaine (FBC)-locally known as "pasta base" or "Paco" in Argentina and the normalization of the consequences of Argentina's 2001-2002 political-economic crisis. On the basis of the results of an ethnographic study carried out in three neighborhoods of the Greater Buenos Aires area between 2001 and 2005, this article aims to analyze how changes in the material and social living conditions are interrelated with the high toxicity of FBC/Paco and engender the emerging compulsion of its consumption and deterioration to the bodies, subjectivities, and social activities of active drug users from these shantytowns. By analyzing the changes in transactions directly or indirectly involving drugs-specifically those ranging from cocaine to FBC/Paco-we can argue how structural poverty, "new poverty," is not only associated with the expansion of FBC/Paco but is also shaped by its use, modes of consumption, associated health problems, and sufferings.

Depth of Cure of New Flowable Composite Resins

DTIC Science & Technology

2012-03-30

Flowable composites were introduced to the dental community in the late 1990’s (Ikeda, 2009; Bayne, 1998). The advantage of flowable composite-based...Depth of Cure of New Flowable Composite Resins A THESIS Presented to the Faculty of The Air Force Postgraduate Dental School...SCIENCE In Oral Biology By Inaam A. Pedalino, BS, DDS Dunn Dental Clinic Lackland AFB, TX 30 March 2012 Depth of Cure of New

Estimates of Forest Biomass Carbon Storage in Liaoning Province of Northeast China: A Review and Assessment

PubMed Central

Yu, Dapao; Wang, Xiaoyu; Yin, You; Zhan, Jinyu; Lewis, Bernard J.; Tian, Jie; Bao, Ye; Zhou, Wangming; Zhou, Li; Dai, Limin

2014-01-01

Accurate estimates of forest carbon storage and changes in storage capacity are critical for scientific assessment of the effects of forest management on the role of forests as carbon sinks. Up to now, several studies reported forest biomass carbon (FBC) in Liaoning Province based on data from China's Continuous Forest Inventory, however, their accuracy were still not known. This study compared estimates of FBC in Liaoning Province derived from different methods. We found substantial variation in estimates of FBC storage for young and middle-age forests. For provincial forests with high proportions in these age classes, the continuous biomass expansion factor method (CBM) by forest type with age class is more accurate and therefore more appropriate for estimating forest biomass. Based on the above approach designed for this study, forests in Liaoning Province were found to be a carbon sink, with carbon stocks increasing from 63.0 TgC in 1980 to 120.9 TgC in 2010, reflecting an annual increase of 1.9 TgC. The average carbon density of forest biomass in the province has increased from 26.2 Mg ha−1 in 1980 to 31.0 Mg ha−1 in 2010. While the largest FBC occurred in middle-age forests, the average carbon density decreased in this age class during these three decades. The increase in forest carbon density resulted primarily from the increased area and carbon storage of mature forests. The relatively long age interval in each age class for slow-growing forest types increased the uncertainty of FBC estimates by CBM-forest type with age class, and further studies should devote more attention to the time span of age classes in establishing biomass expansion factors for use in CBM calculations. PMID:24586881

Estimates of forest biomass carbon storage inLiaoning Province of Northeast China: a review and assessment.

PubMed

Yu, Dapao; Wang, Xiaoyu; Yin, You; Zhan, Jinyu; Lewis, Bernard J; Tian, Jie; Bao, Ye; Zhou, Wangming; Zhou, Li; Dai, Limin

2014-01-01

Accurate estimates of forest carbon storage and changes in storage capacity are critical for scientific assessment of the effects of forest management on the role of forests as carbon sinks. Up to now, several studies reported forest biomass carbon (FBC) in Liaoning Province based on data from China's Continuous Forest Inventory, however, their accuracy were still not known. This study compared estimates of FBC in Liaoning Province derived from different methods. We found substantial variation in estimates of FBC storage for young and middle-age forests. For provincial forests with high proportions in these age classes, the continuous biomass expansion factor method (CBM) by forest type with age class is more accurate and therefore more appropriate for estimating forest biomass. Based on the above approach designed for this study, forests in Liaoning Province were found to be a carbon sink, with carbon stocks increasing from 63.0 TgC in 1980 to 120.9 TgC in 2010, reflecting an annual increase of 1.9 TgC. The average carbon density of forest biomass in the province has increased from 26.2 Mg ha(-1) in 1980 to 31.0 Mg ha(-1) in 2010. While the largest FBC occurred in middle-age forests, the average carbon density decreased in this age class during these three decades. The increase in forest carbon density resulted primarily from the increased area and carbon storage of mature forests. The relatively long age interval in each age class for slow-growing forest types increased the uncertainty of FBC estimates by CBM-forest type with age class, and further studies should devote more attention to the time span of age classes in establishing biomass expansion factors for use in CBM calculations.

Hyperactivity of the default-mode network in first-episode, drug-naive schizophrenia at rest revealed by family-based case-control and traditional case-control designs.

PubMed

Guo, Wenbin; Liu, Feng; Chen, Jindong; Wu, Renrong; Li, Lehua; Zhang, Zhikun; Chen, Huafu; Zhao, Jingping

2017-03-01

Abnormal regional activity and functional connectivity of the default-mode network (DMN) have been reported in schizophrenia. However, previous studies may have been biased by unmatched case-control design. To limit such bias, the present study used both the family-based case-control design and the traditional case-control design to investigate abnormal regional activity of the DMN in patients with schizophrenia at rest.Twenty-eight first-episode, drug-naive patients with schizophrenia, 28 age-, sex-matched unaffected siblings of the patients (family-based controls, FBC), and 40 healthy controls (HC) underwent resting-state functional magnetic resonance imaging (fMRI) scans. The group-independent component analysis and fractional amplitude of low-frequency fluctuation (fALFF) methods were used to analyze the data.Patients with schizophrenia show increased fALFF in an overlapped region of the right superior medial prefrontal cortex (MPFC) relative to the FBC and the HC. Compared with the HC, the patients and the FBC exhibit increased fALFF in an overlapped region of the left posterior cingulate cortex/precuneus (PCC/PCu). Furthermore, the z values of the 2 overlapped regions can separate the patients from the FBC/HC, and separate the patients/FBC from the HC with relatively high sensitivity and specificity.Both the family-based case-control and traditional case-control designs reveal hyperactivity of the DMN in first-episode, drug-naive patients with paranoid schizophrenia, which highlights the importance of the DMN in the neurobiology of schizophrenia. Family-based case-control design can limit the confounding effects of environmental factors in schizophrenia. Combination of the family-based case-control and traditional case-control designs may be a viable option for the neuroimaging studies.

78 FR 69666 - Notice of Receipt of Requests To Voluntarily Cancel Certain Pesticide Registrations

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-20

... stakeholders including environmental, human health, and agricultural advocates; the chemical industry... Liquid Pentachloronitrobenz Flowable. ene. 005481-00442 PCNB Flowable RTU Pentachloronitrobenz Seed... Liquid Pentachloronitrobenz Flowable Seed ene. Treatment Fungicide. 005481-00450 PCNB 20% WDG Soil...

Evaluation of Radiopacity of Bulk-fill Flowable Composites Using Digital Radiography.

PubMed

Tarcin, B; Gumru, B; Peker, S; Ovecoglu, H S

2016-01-01

New flowable composites that may be bulk-filled in layers up to 4 mm are indicated as a base beneath posterior composite restorations. Sufficient radiopacity is one of the several important requirements such materials should meet. The aim of this study was to evaluate the radiopacity of bulk-fill flowable composites and to provide a comparison with conventional flowable composites using digital imaging. Ten standard specimens (5 mm in diameter, 1 mm in thickness) were prepared from each of four different bulk-fill flowable composites and nine different conventional flowable composites. Radiographs of the specimens were taken together with 1-mm-thick tooth slices and an aluminum step wedge using a digital imaging system. For the radiographic exposures, a storage phosphor plate and a dental x-ray unit at 70 kVp and 8 mA were used. The object-to-focus distance was 30 cm, and the exposure time was 0.2 seconds. The gray values of the materials were measured using the histogram function of the software available with the system, and radiopacity was calculated as the equivalent thickness of aluminum. The data were analyzed statistically (p<0.05). All of the tested bulk-fill flowable composites showed significantly higher radiopacity values in comparison with those of enamel, dentin, and most of the conventional flowable composites (p<0.05). Venus Bulk Fill (Heraeus Kulzer) provided the highest radiopacity value, whereas Arabesk Flow (Voco) showed the lowest. The order of the radiopacity values for the bulk-fill flowable composites was as follows: Venus Bulk Fill (Heraeus Kulzer) ≥ X-tra Base (Voco) > SDR (Dentsply DeTrey) ≥ Filtek Bulk Fill (3M ESPE). To conclude, the bulk-fill flowable restorative materials, which were tested in this study using digital radiography, met the minimum standard of radiopacity specified by the International Standards Organization.

Fluidized Bed Boiler Assessment for Navy Applications

DTIC Science & Technology

1986-11-01

rather than removing it from the flue gas later with "scrubbing" devices. Intro- duction of limestone in the bed will reduce SO emissions; two...boiler in a satisfactory manner, the bed level, combustion temperature, and the flue gas composition and temperature should be continuously monitored...The flue gas composition should be c^-ɝely monitored for pollutants and combustion efficiency. EVOLUTION OF FBC BOILERS The performance of FBC

Reinforcement of flowable dental composites with titanium dioxide nanotubes.

PubMed

Dafar, Manal O; Grol, Matthew W; Canham, Peter B; Dixon, S Jeffrey; Rizkalla, Amin S

2016-06-01

Flowable dental composites are used as restorative materials due to their excellent esthetics and rheology. However, they suffer from inferior mechanical properties compared to conventional composites. The aim of this study was to reinforce a flowable dental composite with TiO2 nanotubes (n-TiO2) and to assess the effect of n-TiO2 surface modifications on the mechanical properties of the reinforced composite. n-TiO2 were synthesized using an alkaline hydrothermal process and then functionalized with silane or methacrylic acid (MA). Nanotubes were characterized by scanning and transmission electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy. Commercially available flowable composite (Filtek™ Supreme Ultra Flowable Restorative, 3M ESPE) was reinforced with varying amounts of nanotubes (0-5wt%). Flowability of the resulting composites was evaluated using a Gillmore needle method. Dynamic Young's modulus (E) was measured using an ultrasonic technique. Fracture toughness (KIc) was assessed using a notchless triangular prism and radiopacity was quantified. Viability of NIH/3T3 fibroblasts was evaluated following incubation on composite specimens for 24h. Electron microscopy revealed a tubular morphology of n-TiO2. All reinforced composites exhibited significantly greater values of E than unreinforced composite. Composites reinforced with 3wt% n-TiO2 functionalized with MA exhibited the greatest values of E and KIc. Cytotoxicity assays revealed that reinforced composites were biocompatible. Taken together, flowable composites reinforced with n-TiO2 exhibited mechanical properties superior to those of unreinforced composite, with minimal effects on flowability and radiopacity. n-TiO2-reinforced flowable composites are promising materials for use in dental restorations. Copyright © 2016 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Evaluation of the efficacy of flowable composite as lining material on microleakage of composite resin restorations: A systematic review and meta-analysis.

PubMed

Boruziniat, Alireza; Gharaee, Samineh; Sarraf Shirazi, Alireza; Majidinia, Sara; Vatanpour, Mehdi

2016-02-01

The efficacy of flowable composite in improving marginal adaptation or reducing microleakage is not fully understood. The purpose of this study was to systematically evaluate existing evidence to verify whether an application of flowable composite as a liner provided less microleakage in Class 2 composite restorations. PubMed, ISI (Web of Science), and Scopus databases were searched according to the selected keywords, up to 15 Feb 2015, without any restriction on date or language. Full texts of published articles that seemed to meet primary criteria for inclusion in this research were obtained. Data of studies were extracted if they were assessed as high or moderate level of evidence. Due to the variation of methods used in different studies, they were divided into five groups: groups 1 and 2, studies that evaluated the effect of flowable composite as a liner on dentinal or enamel margins and applied flowable composite on all of the cavity wall margins; groups 3 and 4, studies that evaluated the effect of flowable composite as a liner on dentinal and enamel margins and applied flowable composite only on gingival margin; and group 5, clinical studies. The initial search yielded 1,370 publications. After hand searching, six extra studies were included in the review. The abstracts of all were read independently by AB and SG. After methodologic assessment and evaluation of the level of evidence, 18 studies were selected for this study. The results of this study indicate that flowable composite liners have no significant effect on microleakage of composite restorations in all of five groups. Application of flowable composite as a liner in composite restorations cannot reduce microleakage or improve clinical performance.

Seventeen Years of Using Flowable Resin Restoratives--A Dental Practitioner's Personal Clinical Review.

PubMed

Firla, Markus Th

2015-04-01

Seen through the author's eyes on the basis of his practising dentistry for almost three decades, light-activated flowable resin restoratives (FRCs) or, in common clinical dental terminology, flowable composites have gradually gained major importance in restorative dentistry. Inputs to this ongoing trend are coming from continuous improvements in material properties and the favourable handling characteristics experienced with this particular group of restoratives. Intended to be used in direct adhesive filling procedures, the number and variety of recent generations of flowable composites for lining, restoration of all cavity classes (I-V), core build-ups and, more recently, 'bulk-fill-restorations', however, necessitates a profound clinical understanding of the selective use of flowable composites to ensure clinical success and guarantee long-term high quality results. Clinical relevance: Today's flowable composites allow for reliable restoration of all kinds of defects. However, both the handling characteristics and the material properties of FRCs must be fully understood before taking advantage of their potentially excellent clinical performance.

Observed and projected climate change implications for urban infrastructure and society in the Russian Arctic

NASA Astrophysics Data System (ADS)

Streletskiy, D. A.; Shiklomanov, N. I.; Efimov, S. V.; Shkolnik, I.

2012-12-01

The discoveries of mineral resources followed by an extensive economic development of the Russian North in 1960s led to a development of complex infrastructure on permafrost and urbanization of the Russian Arctic. Despite the mass migration from the northern regions, followed by the collapse of the Soviet Union and the diminishing government support, the Russian Arctic inherited massive infrastructure and remained predominantly urban. Currently, only in five districts bordering Arctic Ocean more than 1.4 million people live in urban-style buildings built on permafrost. Majority of the buildings are constructed assuming the equilibrium conditions of heat-exchange between atmosphere and permafrost underneath. This is usually achieved by construction on piles with ventilated cellars allowing ground cooling in a winter and shading in a summer. The ability of the foundations to carry structural load or foundation bearing capacity (FBC) depends on permafrost properties and changes according to permafrost temperature and active-layer depth. Climate warming observed in recent decades created conditions of diminishing FBC and resulted in deformations and failures of structures built on permafrost. This work is focused on quantitative assessment of these changes at a regional scale. In order to estimate the role of climate change on stability of structures build according to the passive principle, the permafrost-geotechnical model was developed. The historical changes were assessed by comparing model results for period associated with industrialization and construction boom in the Russian North (1965-1975) and present conditions (1995-2005) using NCEP climatic datasets. Projected changes in FBC according to A2 IPCC scenario for the mid-21st century (2041-2060) relative to baseline period (1981-2000) were assessed using output from the ensemble of MGO RCM climate change simulations. It has been found that substantial decrease in FBC will likely occur for the majority of structures built during the industrialization of the Russian North. The decrease of FBC is most pronounced in the regions of West Siberia and Chukotka. The geographic assessment shows that about 0.4 million people currently live in the areas where FBC already decreased by more than 15%. Projected changes of FBC are estimated to be even more significant by the mid 21st century considering 2-4 oC increase in mean annual air temperature in the permafrost regions of Russia. The permafrost temperature increase is modified by changes in snow cover accumulation and continentality and is less than that of the air. Despite that, the decreases in FBC are projected to be quite significant, if not catastrophic in the Russian European North and West Siberia, Western Taymyr and eastern Chukotka (40-50% and more). To mitigate the negative consequences of permafrost warming, the engineering solutions will have to adapt climate projections in construction design, introduce much higher safety coefficients and technological solutions (thermosyphons) to protect permafrost from warming. Failure to do so may result is severe economic and social consequences, as infrastructure in series of large urban settlements will be affected.

In vitro pulp chamber temperature rise from irradiation and exotherm of flowable composites.

PubMed

Baroudi, Kusai; Silikas, Nick; Watts, David C

2009-01-01

The aim of this study was to investigate the pulpal temperature rise induced during the polymerization of flowable and non-flowable composites using light-emitting diode (LED) and halogen (quartz-tungsten-halogen) light-curing units (LCUs). Five flowable and three non-flowable composites were examined. Pulpal temperature changes were recorded over 10 min in a sample primary tooth by a thermocouple. A conventional quartz-tungsten-halogen source and two LEDs, one of which was programmable, were used for light curing the resin composites. Three repetitions per material were made for each LCU. There was a wide range of temperature rises among the materials (P < 0.05). Temperature rises ranged between 1.3 degrees C for Filtek Supreme irradiated by low-power LED and 4.5 degrees C for Grandio Flow irradiated by high-power LED. The highest temperature rises were observed with both the LED high-power and soft-start LCUs. The time to reach the exothermic peak varied significantly between the materials (P < 0.05). Pulpal temperature rise is related to both the radiant energy output from LCUs and the polymerization exotherm of resin composites. A greater potential risk for heat-induced pulp damage might be associated with high-power LED sources. Flowable composites exhibited higher temperature rises than non-flowable materials, because of higher resin contents.

Beyond BMI: Conceptual Issues Related to Overweight and Obese Patients

PubMed Central

Müller, Manfred James; Braun, Wiebke; Enderle, Janna; Bosy-Westphal, Anja

2016-01-01

BMI is widely used as a measure of weight status and disease risks; it defines overweight and obesity based on statistical criteria. BMI is a score; neither is it biologically sound nor does it reflect a suitable phenotype worthwhile to study. Because of its limited value, BMI cannot provide profound insight into obesity biology and its co-morbidity. Alternative assessments of weight status include detailed phenotyping by body composition analysis (BCA). However, predicting disease risks, fat mass, and fat-free mass as assessed by validated techniques (i.e., densitometry, dual energy X ray absorptiometry, and bioelectrical impedance analysis) does not exceed the value of BMI. Going beyond BMI and descriptive BCA, the concept of functional body composition (FBC) integrates body components into regulatory systems. FBC refers to the masses of body components, organs, and tissues as well as to their inter-relationships within the context of endocrine, metabolic and immune functions. FBC can be used to define specific phenotypes of obesity, e.g. the sarcopenic-obese patient. Well-characterized obesity phenotypes are a precondition for targeted research (e.g., on the genomics of obesity) and patient-centered care (e.g., adequate treatment of individual obese phenotypes such as the sarcopenic-obese patient). FBC contributes to a future definition of overweight and obesity based on physiological criteria rather than on body weight alone. PMID:27286962

Radiopacity of flowable composite by a digital technique.

PubMed

Dukić, W; Delija, B; Lešić, S; Dubravica, I; Derossi, D

2013-01-01

The aim of this in vitro study was to evaluate the radiopacity of 19 current dental flowable composite materials by a digital technique. Digital radiographs were obtained with a CCD sensor using an aluminum step wedge, a 1-mm-thick tooth slice, and a 1-mm-thick flowable composite specimen using five different combinations of exposure and voltage. The radiopacity in pixels was determined using Digora 2.6. software. The equivalent thickness of aluminum for each material was then calculated based on the calibration curve. All of the tested flowable composite materials had higher radiopacities than that of dentin, but in almost every combination of exposure and voltage, there were some composite materials that exhibited radiopacities equal to or slightly greater than enamel p>α; α=0.01). Of the flowable composite materials tested, 37% showed lower radiopacities than enamel, and 21% of the tested materials had higher radiopacities than the 3-mm aluminum equivalent. The highest radiopacity at all exposure values was produced by the Majesty Flow and Charisma Opal Flow materials, which had radiopacities almost twice that of enamel. Flowable composite materials should have radiopacities greater than that of enamel (ISO 4049), an important consideration for the introduction of new materials to the market. The digital radiopacity analysis techniques used in this study provide an easy, reliable, rapid, and precise method to characterize radiopacity of dental flowable composite materials.

TANKS 18 AND 19-F STRUCTURAL FLOWABLE GROUT FILL MATERIAL EVALUATION AND RECOMMENDATIONS

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

Stefanko, D.; Langton, C.

2011-11-01

Cementitious grout will be used to close Tanks 18-F and 19-F. The functions of the grout are to: (1) physically stabilize the final landfill by filling the empty volume in the tanks with a non compressible material; (2) provide a barrier for inadvertent intrusion into the tank; (3) reduce contaminant mobility by (a) limiting the hydraulic conductivity of the closed tank and (b) reducing contact between the residual waste and infiltrating water; and (4) providing an alkaline, chemically reducing environment in the closed tank to control speciation and solubility of selected radionuclides. The objective of this work was to identifymore » a single (all-in-one) grout to stabilize and isolate the residual radionuclides in the tank, provide structural stability of the closed tank and serve as an inadvertent intruder barrier. This work was requested by V. A. Chander, High Level Waste (HLW) Tank Engineering, in HLW-TTR-2011-008. The complete task scope is provided in the Task Technical and QA Plan, SRNL-RP-2011-00587 Revision 0. The specific objectives of this task were to: (1) Identify new admixtures and dosages for formulating a zero bleed flowable tank fill material selected by HLW Tank Closure Project personnel based on earlier tank fill studies performed in 2007. The chemical admixtures used for adjusting the flow properties needed to be updated because the original admixture products are no longer available. Also, the sources of cement and fly ash have changed, and Portland cements currently available contain up to 5 wt. % limestone (calcium carbonate). (2) Prepare and evaluate the placement, compressive strength, and thermal properties of the selected formulation with new admixture dosages. (3) Identify opportunities for improving the mix selected by HLW Closure Project personnel and prepare and evaluate two potentially improved zero bleed flowable fill design concepts; one based on the reactor fill grout and the other based on a shrinkage compensating flowable fill mix design. (4) Prepare samples for hydraulic property measurements for comparison to the values in the F and H- Tank Farm Performance Assessments (PAs). (5) Identify a grout mix for the Tanks 18-F and 19-F Grout Procurement Specification [Forty, 2011 a, b, c]. Results for two flowable zero bleed structural fill concepts containing 3/8 inch gravel (70070 Series and LP-8 Series) and a sand only mix (SO Series) are provided in this report. Tank Farm Engineering and SRNL Project Management selected the 70070 mix as the base case for inclusion in Revision 0 of the Tanks 18-F and 19-F grout procurement specification [Forty 2011 a] and requested admixture recommendations and property confirmation for this formulation [Forty, 2011 b]. Lower cementitious paste mixes were formulated because the 70070 mix is over designed with respect to strength and generates more heat from hydration reactions than is desirable for mass pour application. Work was also initiated on a modification of the recommended mix which included shrinkage compensation to mitigate fast pathways caused by shrinkage cracking and poor physical bonding to the tank and ancillary equipment. Testing of this option was postponed to FY12.« less

FBC: a flat binary code scheme for fast Manhattan hash retrieval

NASA Astrophysics Data System (ADS)

Kong, Yan; Wu, Fuzhang; Gao, Lifa; Wu, Yanjun

2018-04-01

Hash coding is a widely used technique in approximate nearest neighbor (ANN) search, especially in document search and multimedia (such as image and video) retrieval. Based on the difference of distance measurement, hash methods are generally classified into two categories: Hamming hashing and Manhattan hashing. Benefitting from better neighborhood structure preservation, Manhattan hashing methods outperform earlier methods in search effectiveness. However, due to using decimal arithmetic operations instead of bit operations, Manhattan hashing becomes a more time-consuming process, which significantly decreases the whole search efficiency. To solve this problem, we present an intuitive hash scheme which uses Flat Binary Code (FBC) to encode the data points. As a result, the decimal arithmetic used in previous Manhattan hashing can be replaced by more efficient XOR operator. The final experiments show that with a reasonable memory space growth, our FBC speeds up more than 80% averagely without any search accuracy loss when comparing to the state-of-art Manhattan hashing methods.

The Systems Biology Markup Language (SBML) Level 3 Package: Flux Balance Constraints.

PubMed

Olivier, Brett G; Bergmann, Frank T

2015-09-04

Constraint-based modeling is a well established modelling methodology used to analyze and study biological networks on both a medium and genome scale. Due to their large size, genome scale models are typically analysed using constraint-based optimization techniques. One widely used method is Flux Balance Analysis (FBA) which, for example, requires a modelling description to include: the definition of a stoichiometric matrix, an objective function and bounds on the values that fluxes can obtain at steady state. The Flux Balance Constraints (FBC) Package extends SBML Level 3 and provides a standardized format for the encoding, exchange and annotation of constraint-based models. It includes support for modelling concepts such as objective functions, flux bounds and model component annotation that facilitates reaction balancing. The FBC package establishes a base level for the unambiguous exchange of genome-scale, constraint-based models, that can be built upon by the community to meet future needs (e. g. by extending it to cover dynamic FBC models).

The Systems Biology Markup Language (SBML) Level 3 Package: Flux Balance Constraints.

PubMed

Olivier, Brett G; Bergmann, Frank T

2015-06-01

Constraint-based modeling is a well established modelling methodology used to analyze and study biological networks on both a medium and genome scale. Due to their large size, genome scale models are typically analysed using constraint-based optimization techniques. One widely used method is Flux Balance Analysis (FBA) which, for example, requires a modelling description to include: the definition of a stoichiometric matrix, an objective function and bounds on the values that fluxes can obtain at steady state. The Flux Balance Constraints (FBC) Package extends SBML Level 3 and provides a standardized format for the encoding, exchange and annotation of constraint-based models. It includes support for modelling concepts such as objective functions, flux bounds and model component annotation that facilitates reaction balancing. The FBC package establishes a base level for the unambiguous exchange of genome-scale, constraint-based models, that can be built upon by the community to meet future needs (e. g. by extending it to cover dynamic FBC models).

Potential of scrap tire rubber as lightweight aggregate in flowable fill.

PubMed

Pierce, C E; Blackwell, M C

2003-01-01

Flowable fill is a self-leveling and self-compacting material that is rapidly gaining acceptance and application in construction, particularly in transportation and utility earthworks. When mixed with concrete sand, standard flowable fill produces a mass density ranging from 1.8 to 2.3 g/cm(3) (115-145 pcf). Scrap tires can be granulated to produce crumb rubber, which has a granular texture and ranges in size from very fine powder to coarse sand-sized particles. Due to its low specific gravity, crumb rubber can be considered a lightweight aggregate. This paper describes an experimental study on replacing sand with crumb rubber in flowable fill to produce a lightweight material. To assess the technical feasibility of using crumb rubber, the fluid- and hardened-state properties of nine flowable fill mixtures were measured. Mixture proportions were varied to investigate the effects of water-to-cement ratio and crumb rubber content on fill properties. Experimental results indicate that crumb rubber can be successfully used to produce a lightweight flowable fill (1.2-1.6 g/cm(3) [73-98 pcf]) with excavatable 28-day compressive strengths ranging from 269 to 1194 kPa (39-173 psi). Using a lightweight fill reduces the applied stress on underlying soils, thereby reducing the potential for bearing capacity failure and minimizing soil settlement. Based on these results, a crumb rubber-based flowable fill can be used in a substantial number of construction applications, such as bridge abutment fills, trench fills, and foundation support fills.

The green highway forum

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

NONE

2006-07-01

In late 2004, as part of American Coal Ash Association's (ACAA) strategic planning process, a plan was approved by its Board of Directors implementing a 'green highways' concept which emphasized use of coal combustion products (CCPs) in highways in a variety of ways including being used alone, in combination with other forms of CCPs, and combined with non ash materials. The incentives behind the developed concept were the derived advantages from beneficial technical economic and environmental impacts. Although the primary use of fly ash is concrete, other forms of CCPs could be considered for more non-traditional highway applications. For example,more » these might include soils stabilization, binders for in-place pavement recycling, use in flowable fills, aggregates, source materials for structural fills and embankments, components in manufactured soils, and for granular base courses beneath pavements. At this same time, unknown to ACCA, EPA Region 3 in Philadelphia was working with the Wetlands and Watershed Work Group, a non-profit organization involved in wetlands policy and management along with the Federal Highway Administration (FHWA) on their own Green Highways initiative. These groups were planning a conference, the 'Green Highway Forum'. This was held in College Park, Maryland at the University of Maryland, Nov 8-10 2005. At the conference a draft 'roadmap' was presented as a guide to executive level participants bringing the diverse viewpoints of many agencies and interest groups together. Ten guiding principals were considered. The 'Green Highways' is a new effort to recognize the 'greenness' of many projects already completed and those to be initiated. 2 photos.« less

Polycyclic aromatic hydrocarbon (PAH) emissions from a coal-fired pilot FBC system.

PubMed

Liu, K; Han, W; Pan, W P; Riley, J T

2001-06-29

Due to the extensive amount of data suggesting the hazards of these compounds, 16 polycyclic aromatic hydrocarbons (PAHs) are on the Environmental Protection Agency (EPA) Priority Pollutant List. Emissions of these PAHs in the flue gas from the combustion of four coals were measured during four 1000h combustion runs using the 0.1MW heat-input (MWth) bench-scale fluidized bed combustor (FBC). An on-line sampling system was designed for the 16 PAHs, which consisted of a glass wool filter, condenser, glass fiber filter, Teflon filter, and a Tenax trap. The filters and Tenax were extracted by methylene chloride and hexane, respectively, followed by GC/MS analysis using the selective ion monitoring (SIM) mode. In this project, the effects of operating parameters, limestone addition, chlorine content in the coal, and Ca/S molar ratio on the emissions of PAHs were studied. The results indicated that the emissions of PAHs in an FBC system are primarily dependent on the combustion temperature and excess air ratio. The injection of secondary air with high velocity in the freeboard effectively reduces PAH emissions. The addition of extra limestone can promote the formation of PAHs in the FBC system. Chlorine in the coal can possibly lead to large benzene ring PAH formation during combustion. The total PAH emission increases with an increase in the sulfur content of coal. Incomplete combustion results in PAHs with four or more benzene rings. High efficiency combustion results in PAHs with two or three benzene rings.

Physico-chemical characteristics of microwave-dried wheat distillers grain with solubles.

PubMed

Mosqueda, Maria Rosario P; Tabil, Lope G; Meda, Venkatesh

2013-01-01

Laboratory-prepared samples of wheat distillers grain with solubles with varying condensed distillers solubles (CDS) content were dried under varying microwave power, and microwave convection settings using a domestic microwave oven to examine their effect on the chemical, structural, color, flow, compression, thermal, and frictional properties of the product, which is dried distillers grain with solubles (DDGS). As CDS level increased, protein and ash content increased, while fat and fiber content decreased in wheat-based DDGS. Fat content was also markedly effected by the microwave oven drying conditions. While CDS level, microwave power or microwave convection setting, and/or their interactions significantly effected a number of physical properties; results indicated that CDS level had a stronger influence compared to the other factors. DDGS samples with high CDS levels were significantly denser, finer but more differentiated in size, less flowable, and less dispersible. These also produced denser and stronger pellets.

Towards High-Energy-Density Pseudocapacitive Flowable Electrodes by the Incorporation of Hydroquinone

DOE PAGES

Boota, M.; Hatzell, K. B.; Kumbur, E. C.; ...

2015-01-29

Our study reports an investigation of hydroquinone (HQ) as a multielectron organic redox molecule to enhance the performance of flowable electrodes. Moreover, two different methods to produce high-performance pseudocapacitive flowable electrodes were investigated for electrochemical flow capacitors. First, HQ molecules were deposited on carbon spheres (CSs) by a self-assembly approach using various HQ loadings. In the second approach, HQ was used as a redox-mediating agent in the electrolyte. Flowable electrodes composed of HQ showed a capacitance of 342 Fg 1, which is >200% higher than that of flowable electrodes based on nontreated CSs (160 Fg 1), and outperformed (in gravimetricmore » performance) many reported film electrodes. A similar trend in capacitance was observed if HQ was used as a redox agent in the electrolyte; however, its poor cycle life restricted further consideration. Additionally, a twofold increase in capacitance was observed under flow conditions compared to that of previous studies.« less

The effect of additional enamel etching and a flowable composite to the interfacial integrity of Class II adhesive composite restorations.

PubMed

Belli, S; Inokoshi, S; Ozer, F; Pereira, P N; Ogata, M; Tagami, J

2001-01-01

This in vitro study evaluated the interfacial integrity of Class II resin composite restorations. The influence of a flowable composite and additional enamel etching was also evaluated. Deep, saucer-shaped Class II cavities were prepared in the mesial and distal proximal surfaces of 25 extracted human molars and assigned to five treatment groups. The gingival margins were extended to approximately 1 mm above the CEJ in 40 cavities and below the CEJ in 10 cavities. The prepared cavities were then restored with a self-etching primer system (Clearfil Liner Bond II) and a hybrid resin composite (Clearfil AP-X), with and without a flowable composite (Protect Liner F) and additional enamel etching with 37% phosphoric acid gel (K-etchant). After finishing, polishing and thermocycling (4 and 60 degrees C, x300), the samples were longitudinally sectioned through the restorations and resin-tooth interfaces were observed directly under a laser scanning microscope. Statistical analysis indicated that the use of a flowable composite produced significantly more (p = 0.04) gap-free resin-dentin interfaces than teeth restored without the flowable composite. However, both flowable composite and enamel etching could not prevent gap formation at enamel-resin interfaces and crack formation on enamel walls.

Simulation of fluidized bed coal combustors

NASA Technical Reports Server (NTRS)

Rajan, R.

1979-01-01

The many deficiencies of previous work on simulation of fluidized bed combustion (FBC) processes are presented. An attempt is made to reduce these deficiencies, and to formulate a comprehensive FBC model taking into account the following elements: (1) devolatilization of coal and the subsequent combustion of volatiles and residual char; (2) sulfur dioxide capture by limestone; (3) NOx release and reduction of NOx by char; (4) attrition and elutriation of char and limestone; (5) bubble hydrodynamics; (6) solids mixing; (7) heat transfer between gas and solid, and solid and heat exchange surfaces; and (8) freeboard reactions.

Evaluation of the pH of a Self-Adhesive Flowable Composite Over 3 Months

DTIC Science & Technology

2016-04-01

Flowable Materials. Dental Research Journal 2012; 9(4): 460-465. 12. Goracci C, Margvelashvili M, Giovannetti A, Vichi A, Ferrari M: Shear Bond...responsible for the vast field of current products on the dental market today. These developments have led researchers to focus on combining the...reduces internal voids. Some studies even show better marginal adaptation when a flowable composite is used, though some research shows it doesn’t

Metal sulfide electrodes and energy storage devices thereof

DOEpatents

Chiang, Yet-Ming; Woodford, William Henry; Li, Zheng; Carter, W. Craig

2017-02-28

The present invention generally relates to energy storage devices, and to metal sulfide energy storage devices in particular. Some aspects of the invention relate to energy storage devices comprising at least one flowable electrode, wherein the flowable electrode comprises an electroactive metal sulfide material suspended and/or dissolved in a carrier fluid. In some embodiments, the flowable electrode further comprises a plurality of electronically conductive particles suspended and/or dissolved in the carrier fluid, wherein the electronically conductive particles form a percolating conductive network. An energy storage device comprising a flowable electrode comprising a metal sulfide electroactive material and a percolating conductive network may advantageously exhibit, upon reversible cycling, higher energy densities and specific capacities than conventional energy storage devices.

Dispensability of Annual Laboratory Follow-Up After More than 2 Years of Valproic Acid Use: A Systematic Review.

PubMed

Meijboom, Rosanne W; Grootens, Koen P

2017-11-01

The necessity of annual laboratory follow-up in patients treated with valproic acid (VPA) is controversial. We investigated the need for annual laboratory follow-up of liver enzymes, electrolytes, and full blood count (FBC) in patients treated with VPA. A systematic search in Evidence-Based Medicine Reviews (EBMR), MEDLINE, and EMBASE was undertaken in December 2016 to identify all published articles investigating or citing valproic acid, liver function disorders, electrolyte disorders, and FBC deviations. This review included 108 articles. As the number of participants and duration of the study was not adequate in most studies to detect rare adverse events, studies did not demonstrate a clear prevalence of hepatotoxicity. While a transient increase of transaminases is common and seldom harmful, severe hepatotoxicity is a rare phenomenon and is not prevented by routine laboratory monitoring. VPA had no relevant effect on serum calcium, sodium, potassium, and albumin. The prevalence of FBC varied from 0.6 to 27.8%, occurred mostly in the first 2 years of therapy, and was usually asymptomatic. Long-term monitoring in VPA treatment is only necessary when there have been dose adjustments, co-medication switches, or co-morbidity. In uncomplicated cases, annual laboratory follow-up may be discontinued after 2 years of VPA treatment. Encouraging patients to be vigilant is more effective in the detection of hepatotoxicity than laboratory testing. Follow-up of FBC at 3-6 months, 1 year, and 2 years after start or after a dose increase of VPA or interacting medication is sufficient.

Efficacy of alum and coal combustion by-products in stabilizing manure phosphorus.

PubMed

Dou, Z; Zhang, G Y; Stout, W L; Toth, J D; Ferguson, J D

2003-01-01

Animal manures contain large amounts of soluble phosphorus (P), which is prone to runoff losses when manure is surface-applied. Here we report the efficacy of alum and three coal combustion by-products in reducing P solubility when added to dairy, swine, or broiler litter manures in a laboratory incubation study. Compared with unamended controls, alum effectively reduced readily soluble P, determined in water extracts of moist manure samples with 1 h of shaking, for all three manures. The reduction ranged from 80 to 99% at treatment rates of 100 to 250 g alum kg(-1) manure dry matter. The fluidized bed combustion fly ash (FBC) reduced readily soluble P by 50 to 60% at a rate of 400 g kg(-1) for all three manures. Flue gas desulfurization by-product (FGD) reduced readily soluble P by nearly 80% when added to swine manure and broiler litter at 150 and 250 g kg(-1). Another by-product, anthracite refuse fly ash (ANT), was ineffective for all three manures. In all cases, reduction in readily soluble P is primarily associated with inorganic phosphorus (P(i)) with little change in organic phosphorus (P(o)). Sequential extraction results indicate that the by-product treatments shifted manure P from H2O-P into a less vulnerable fraction, NaHCO3 - P, while the alum treatment shifted the P into even more stable forms, mostly NaOH-P. Such shifts in P fractions would have little influence on P availability for crops over the long-term but would retard and reduce potential losses of P following manure applications.

Flowable Resin Composites: A Systematic Review and Clinical Considerations

PubMed Central

Rodrigues, Jean C.

2015-01-01

Background Little is known about flowable composite materials. Most literature mentions conventional composite materials at large, giving minimal emphasis to flowables in particular. This paper briefly gives an in depth insight to the multiple facets of this versatile material. Aim To exclusively review the most salient features of flowable composite materials in comparison to conventional composites and to give clinicians a detailed understanding of the advantages, drawbacks, indications and contraindications based on composition and physical/mechanical properties. Methodology Data Sources: A thorough literature search from the year 1996 up to January 2015 was done on PubMed Central, The Cochrane Library, Science Direct, Wiley Online Library, and Google Scholar. Grey literature (pending patents, technical reports etc.) was also screened. The search terms used were “dental flowable resin composites”. Search Strategy After omitting the duplicates/repetitions, a total of 491 full text articles were assessed. As including all articles were out of the scope of this paper. Only relevant articles that fulfilled the reviewer’s objectives {mentioning indications, contraindications, applications, assessment of physical/mechanical/biological properties (in vitro/ in vivo /ex vivo)} were considered. A total of 92 full text articles were selected. Conclusion Flowable composites exhibit a variable composition and consequently variable mechanical/ physical properties. Clinicians must be aware of this aspect to make a proper material selection based on specific properties and indications of each material relevant to a particular clinical situation. PMID:26266238

Tanks 18 And 19-F Structural Flowable Grout Fill Material Evaluation And Recommendations

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

Langton, C. A.; Stefanko, D. B.

2013-04-23

Cementitious grout will be used to close Tanks 18-F and 19-F. The functions of the grout are to: 1) physically stabilize the final landfill by filling the empty volume in the tanks with a non-compressible material; 2) provide a barrier for inadvertent intrusion into the tank; 3) reduce contaminant mobility by a) limiting the hydraulic conductivity of the closed tank and b) reducing contact between the residual waste and infiltrating water; and 4) providing an alkaline, chemically reducing environment in the closed tank to control speciation and solubility of selected radionuclides. The objective of this work was to identify amore » single (all-in-one) grout to stabilize and isolate the residual radionuclides in the tank, provide structural stability of the closed tank and serve as an inadvertent intruder barrier. This work was requested by V. A. Chander, High Level Waste (HLW) Tank Engineering, in HLW-TTR-2011-008. The complete task scope is provided in the Task Technical and QA Plan, SRNL-RP-2011-00587 Revision 0. The specific objectives of this task were to: 1) Identify new admixtures and dosages for formulating a zero bleed flowable tank fill material selected by HLW Tank Closure Project personnel based on earlier tank fill studies performed in 2007. The chemical admixtures used for adjusting the flow properties needed to be updated because the original admixture products are no longer available. Also, the sources of cement and fly ash have changed, and Portland cements currently available contain up to 5 wt. % limestone (calcium carbonate). 2) Prepare and evaluate the placement, compressive strength, and thermal properties of the selected formulation with new admixture dosages. 3) Identify opportunities for improving the mix selected by HLW Closure Project personnel and prepare and evaluate two potentially improved zero bleed flowable fill design concepts; one based on the reactor fill grout and the other based on a shrinkage compensating flowable fill mix design. 4) Prepare samples for hydraulic property measurements for comparison to the values in the F and H- Tank Farm Performance Assessments (PAs). 5) Identify a grout mix for the Tanks 18-F and 19-F Grout Procurement Specification [Forty, 2011 a, b, c]. Results for two flowable zero bleed structural fill concepts containing 3/8 inch gravel (70070 Series and LP#8 Series) and a sand only mix (SO Series) are provided in this report. Tank Farm Engineering and SRNL Project Management selected the 70070 mix as the base case for inclusion in Revision 0 of the Tanks 18-F and 19-F grout procurement specification [Forty 2011 a] and requested admixture recommendations and property confirmation for this formulation [Forty, 2011 b]. Lower cementitious paste mixes were formulated because the 70070 mix is over designed with respect to strength and generates more heat from hydration reactions than is desirable for mass pour application. Work was also initiated on a modification of the recommended mix which included shrinkage compensation to mitigate fast pathways caused by shrinkage cracking and poor physical bonding to the tank and ancillary equipment. Testing of this option was postponed to FY12. Mix, LP#8-16 is recommended for inclusion in the specification for furnishing and delivering tank closure grout for Tanks 18-F and 19-F [Forty, 2011 c]. A shrinkage compensating variation of this mix, LP#16C, has not been fully developed and characterized at this time.« less

Flowability of JSC-1a

NASA Technical Reports Server (NTRS)

Rame, Enrique; Wilkinson, Allen; Elliot, Alan; Young, Carolyn

2009-01-01

We have done a complete flowability characterization of the lunar soil simulant, JSC-1a, following closely the ASTM-6773 standard for the Schulze ring shear test. The measurements, which involve pre-shearing the material before each yield point, show JSC-1a to be cohesionless, with an angle of internal friction near 40 deg. We also measured yield loci after consolidating the material in a vibration table which show it to have significant cohesion (approximately equal to 1 kPa) and an angle of internal friction of about 60 deg. Hopper designs based on each type of flowability test differ significantly. These differences highlight the need to discern the condition of the lunar soil in the specific process where flowability is an issue. We close with a list not necessarily comprehensive of engineering rules of thumb that apply to powder flow in hoppers.

Epidemiological and clinicopathological characteristics of BRCA-positive and BRCA-negative breast cancer patients in Greece.

PubMed

Triantafyllidou, Olga; Vlachos, Ioannis S; Apostolou, Paraskevi; Konstantopoulou, Irene; Grivas, Anastasios; Panopoulos, Christos; Dimitrakakis, Constantine; Kassanos, Dimitrios; Loghis, Constantine; Bramis, Ioannis; Vlahos, Nikolaos; Yannoukakos, Drakoulis; Fostira, Florentia

2015-01-01

BRCA mutation carriers can benefit from targeted clinical interventions. On the other hand, families with evident aggregation of breast cancer (BC) cases and a BRCA-negative genetic test can still be considered as of elevated risk, since the underlying genetic factor remains unidentified. In the present study, we compared clinical and demographic characteristics between BRCA1 mutation carriers (BRCA1mut) and non-carriers (non-BRCA1) in a Greek group of BC patients (n=321). Data were collected and analyzed from 321 women with BC, with 131 patients screened for pathogenic mutations in the high-penetrant genes BRCA1 and BRCA2. Collected data included demographics, pedigrees, tumor histopathology and immunohistochemistry findings. In BRCA1mut patients, their mothers and grand- mothers were diagnosed at a younger age compared to non-BRCA1-carriers. Additionally, BRCA1mut patients were diagnosed with mainly estrogen receptor (ER) negative (p<0.001), Her-2 negative (p<0.05) and triple negative (p<0.01) tumors. The youngest generation was diagnosed with familial breast cancer (FBC) 9.7 years earlier than their mothers (p<0.001). Age at BC diagnosis negatively correlated with the nuclear grade of breast tumors (r=-0.3, p<0.05). Among parous individuals, the number of full-term pregnancies significantly correlated with the age at BC onset (r=0.19, p<0.05). Despite their similarities, FBC cases with identified BRCA1 mutations exhibit a clearly distinct profile. We have identified an anticipation effect in FBC patients, with significantly reduced age at diagnosis in younger generations. Increased parity seems to prevent early BC onset. This is the first study comparing clinical and demographic characteristics of FBC BRCA1mut and non-carriers in a Greek cohort.

Sugar snack consumption in Ugandan schoolchildren: Validity and reliability of a food frequency questionnaire.

PubMed

Kiwanuka, S N; Astrøm, A N; Trovik, T A

2006-10-01

This study assessed the reproducibility and relative validity of an eight-item self-administered food frequency questionnaire (FFQ) on intake of sugared snacks in Ugandan schoolchildren. A 5-day precoded food behaviour checklist (FBC) was used as validation criteria. Sociodemographic correlates of a sum frequency sugar score were explored. The study was conducted in Kampala, Uganda, in 2004. Six hundred and fourteen schoolchildren (mean age 12.4 years) completed the FFQ on cakes/biscuits, chocolate, ice sticks, soft drinks, coffee, tea, sugared desserts and sweets/candies at school. They were examined clinically for dental caries. Forty students completed the FFQ twice, 1 week apart and 325 students completed the 5 day FBC at school. The mean decayed, missing and filled tooth index score was 0.98 (SD 1.6, range 0-15). Reproducibility scores (Cohen's kappa) for the sugar items ranged from 0.17 (ice sticks) to 0.55 (biscuits). No differences were seen between the average intakes at test and retest. Higher intake was reported in FFQ than in FBC across all sugar items. Crude agreement between students reporting intake at least 3-5 times a week/less than three times a week ranged from 50% to 55% (e.g. biscuits, chocolate) to 87% (tea). Spearman's correlation coefficients ranged from 0.14 (desserts) to 0.27 (sweets). anova revealed significant increase (P = 0.001) in the mean FBC sum scores by increasing quartiles of the FFQ sum scores. The average sum FFQ sugar scores were higher in girls than in boys and higher in older than in younger students. Fair reproducibility was established for the FFQ sugar items. The FFQ was acceptable in classifying individuals into broad categories of low and high sugar consumption.

Cultural, Transcriptomic, and Proteomic Analyses of Water-Stressed Cells of Actinobacterial Strains Isolated from Compost: Ecological Implications in the Fed-Batch Composting Process.

PubMed

Narihiro, Takashi; Kanosue, Yuji; Hiraishi, Akira

2016-06-25

This study was undertaken to examine the effects of water activity (aw) on the viability of actinobacterial isolates from a fed-batch composting (FBC) process by comparing culturability and stainability with 5-cyano-2,3-ditoryl tetrazolium chloride (CTC). The FBC reactor as the source of these bacteria was operated with the daily loading of household biowaste for 70 d. During this period of composting, aw in the reactor decreased linearly with time and reached approximately 0.95 at the end of operation. The plate counts of aerobic chemoorganotrophic bacteria were 3.2-fold higher than CTC-positive (CTC+) counts on average at the fully acclimated stage (after 7 weeks of operation), in which Actinobacteria predominated, as shown by lipoquinone profiling and cultivation methods. When the actinobacterial isolates from the FBC process were grown under aw stress, no significant differences were observed in culturability among the cultures, whereas CTC stainability decreased with reductions in aw levels. A cDNA microarray-based transcriptomic analysis of a representative isolate showed that many of the genes involved in cellular metabolism and genetic information processing were down-regulated by aw stress. This result was fully supported by a proteomic analysis. The results of the present study suggest that, in low aw mature compost, the metabolic activity of the community with Actinobacteria predominating is temporarily reduced to a level that hardly reacts with CTC; however, these bacteria are easily recoverable by exposure to a high aw culture medium. This may be a plausible reason why acclimated FBC reactors in which Actinobacteria predominate yields higher plate counts than CTC+ counts.

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

Mutanen, K.I.

Development of fluidized bed combustion (FBC) was started both in North America and in Europe in the 1960`s. In Europe and especially in Scandinavia the major driving force behind the development was the need to find new more efficient technologies for utilization of low-grade fuels like different biomasses and wastes. Both bubbling fluidized bed (BFB) and circulating fluidized bed (CFB) technologies were under intensive R&D,D efforts and have now advanced to dominating role in industrial and district heating power plant markets in Europe. New advanced CFB designs are now entering the markets. In North America and especially in the USmore » the driving force behind the FBC development was initially the need to utilize different types of coals in a more efficient and environmentally acceptable way. The present and future markets seem to be mainly in biomass and multifuel applications where there is benefit from high combustion efficiency, high fuel flexibility and low emissions such as in the pulp and paper industry. The choice between CFB technology and BFB technology is based on selected fuels, emission requirements, plant size and on technical and economic feasibility. Based on Scandinavian experience there is vast potential in the North American industry to retrofit existing oil fired, pulverized coal fired, chemical recovery or grate fired boilers with FBC systems or to build a new FBC based boiler plant. This paper will present the status of CFB technologies and will compare technical and economic feasibility of CFB technology to CFB technology to BFB and also to other combustion methods. Power plant projects that are using advanced CFB technology e.g. Ahlstrom Pyroflow Compact technology for biomass firing and co-firing of biomass with other fuels will also be introduced.« less

Mechanical properties of dust collected by dust separators in iron ore sinter plants.

PubMed

Lanzerstorfer, Christof

2015-01-01

The flow-related mechanical properties of dusts from the de-dusting systems of several sinter plants were investigated. The mass median diameters of the dusts were in the range from approximately 3 to 100 µm. Also, the bulk density of the dusts varied in a wide range (approximately 400 to 2300 kg/m³). A good correlation between the bulk density and the mass median diameter for most of the dusts was found. In contrast, the angles of repose did not vary very much, only for the coarsest dust a significantly lower value was measured. The angles of internal friction as well as the wall friction angles were lower for coarse dust and higher for fine dust. The shear tests showed that both angles depend considerably on the stress level. At low stress, the angles decreased significantly with increasing values of stress, whereas at higher stress, the dependence was small or even disappeared. The only exception to this behaviour was shown by the finest dust. The flowability decreased with the particle size. The flowability categories suggested by the three flowability indicators were passable only for the coarser dusts. For the finer dusts, the flowability was overestimated by all flowability indicators.

Experiments on fuel heating for commercial aircraft

NASA Technical Reports Server (NTRS)

Friedman, R.; Stockemer, F. J.

1982-01-01

An experimental jet fuel with a -33 C freezing point was chilled in a wing tank simulator with superimposed fuel heating to improve low temperature flowability. Heating consisted of circulating a portion of the fuel to an external heat exchanger and returning the heated fuel to the tank. Flowability was determined by the mass percent of unpumpable fuel (holdup) left in the simulator upon withdrawal of fuel at the conclusion of testing. The study demonstrated that fuel heating is feasible and improves flowability as compared to that of baseline, unheated tests. Delayed heating with initiation when the fuel reaches a prescribed low temperature limit, showed promise of being more efficient than continuous heating. Regardless of the mode or rate of heating, complete flowability (zero holdup) could not be restored by fuel heating. The severe, extreme-day environment imposed by the test caused a very small amount of subfreezing fuel to be retained near the tank surfaces even at high rates of heating. Correlations of flowability established for unheated fuel tests also could be applied to the heated test results if based on boundary-layer temperature or a solid index (subfreezing point) characteristic of the fuel.

Effect of Layering Methods, Composite Type, and Flowable Liner on the Polymerization Shrinkage Stress of Light Cured Dental Composites

DTIC Science & Technology

2011-08-01

composite (Z350 flowable: 3M ESPE), and a silorane-based composite (P90: 3M ESPE). Scotchbond multipurpose adhesive ( 3M ESPE) was applied prior to...syringe. Composites used for filling the cavities were a methacrylate-based universal hybrid composite (Z250: 3M ESPE, St. Paul, MN, USA), a flowable... adhesive was light cured for 10 s using a LED light curing unit (S10: 3M ESPE), and the light intensity was 1200 mW/cm 2 . An acrylic case with

Bilateral first branchial cleft anomaly with evidence of a genetic aetiology.

PubMed

Gonzalez-Perez, L M; Prats-Golczer, V E; Montes Carmona, J F; Heurtebise Saavedra, J M

2014-03-01

Anomalies of the first branchial cleft (FBC) are uncommon, and recognizing them can be difficult. Although present at birth, many cases do not become evident until later in childhood or adolescence, with an initial clinical presentation in adulthood being encountered only rarely. Typically, FBC anomalies present as a unilateral cyst, sinus, or fistula associated with the external auditory canal, or with swelling or an inflammatory opening in the peri-auricular/parotid area. They are commonly misdiagnosed and are often treated inadequately before being excised completely. A 40-year-old woman presented to the maxillofacial outpatient clinic with an episode of bilateral pre-auricular tumefaction, initially diagnosed as temporomandibular dysfunction syndrome. This was associated with bilateral pre-auricular pain that increased with mandibular movements. In relation to the patient's history, and given the bilateral presence of a pre-auricular pit, a diagnosis of FBC anomaly was made. Further investigation showed a related asymptomatic history in five other cases across four generations of the same family. The authors describe here the case, the diagnostic methodology, and the wide local excision technique used for removal of the branchial sinus. Copyright © 2013 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Management of Male Breast Cancer in the United States: A Surveillance, Epidemiology and End Results Analysis

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

Fields, Emma C., E-mail: emma.fields@ucdenver.edu; DeWitt, Peter; Fisher, Christine M.

Purpose: To analyze the stage-specific management of male breast cancer (MBC) with surgery and radiation therapy (RT) and relate them to outcomes and to female breast cancer (FBC). Methods and Materials: The Surveillance, Epidemiology, and End Results database was queried for all primary invasive MBC and FBC diagnosed from 1973 to 2008. Analyzable data included age, race, registry, grade, stage, estrogen and progesterone receptor status, type of surgery, and use of RT. Stage was defined as localized (LocD): confined to the breast; regional (RegD): involving skin, chest wall, and/or regional lymph nodes; and distant: M1. The primary endpoint was cause-specificmore » survival (CSS). Results: A total of 4276 cases of MBC and 718,587 cases of FBC were identified. Male breast cancer constituted 0.6% of all breast cancer. Comparing MBC with FBC, mastectomy (M) was used in 87.4% versus 38.3%, and breast-conserving surgery in 12.6% versus 52.6% (P<10{sup −4}). For males with LocD, CSS was not significantly different for the 4.6% treated with lumpectomy/RT versus the 70% treated with M alone (hazard ratio [HR] 1.33; 95% confidence interval [CI] 0.49-3.61; P=.57). Postmastectomy RT was delivered in 33% of males with RegD and was not associated with an improvement in CSS (HR 1.11; 95% CI 0.88-1.41; P=.37). There was a significant increase in the use of postmastectomy RT in MBC over time: 24.3%, 27.2%, and 36.8% for 1973-1987, 1988-1997, and 1998-2008, respectively (P<.0001). Cause-specific survival for MBC has improved: the largest significant change was identified for men diagnosed in 1998-2008 compared with 1973-1987 (HR 0.73; 95% CI 0.60-0.88; P=.0004). Conclusions: Surgical management of MBC is dramatically different than for FBC. The majority of males with LocD receive M despite equivalent CSS with lumpectomy/RT. Postmastectomy RT is greatly underutilized in MBC with RegD, although a CSS benefit was not demonstrated. Outcomes for MBC are improving, attributable to improved therapy and its use in this unscreened population.« less

Setting Ideal Lubricant Mixing Time for Manufacturing Tablets by Evaluating Powder Flowability.

PubMed

Nakamura, Shohei; Yamaguchi, Saori; Hiraide, Rikiha; Iga, Kumi; Sakamoto, Takatoshi; Yuasa, Hiroshi

2017-10-01

We investigated the effectiveness of using Carr's flowability index (FI) and practical angle of internal friction (Φ) as indexes for setting the target Mg-St mixing time needed for preparing tablets with the target physical properties. We used FI as a measure of flowability under non-loaded conditions, and Φ as a measure of flowability under loaded conditions for pharmaceutical powders undergoing direct compression with varying concentrations of Mg-St and mixing times. We evaluated the relationship between Mg-St mixing conditions and pharmaceutical powder flowability, analyzed the correlation between the physical properties of the tablets (i.e., tablet weight variation, drug content uniformity, hardness, friability, and disintegration time of tablets prepared using the pharmaceutical powder), and studied the effect of Mg-St mixing conditions and pharmaceutical powder flowability on tablet properties. Mg-St mixing time highly correlated with pharmaceutical powder FI (R 2  = 0.883) while Mg-St concentration has low correlation with FI, and FI highly correlated with the physical properties of the tablet (R 2 values: weight variation 0.509, drug content variation 0.314, hardness 0.525, friability 0.477, and disintegration time 0.346). Therefore, using pharmaceutical powder FI as an index could enable prediction of the physical properties of a tablet without the need for tableting, and setting the Mg-St mixing time by using pharmaceutical powder FI could enable preparation of tablets with the target physical properties. Thus, the FI of the intermediate product (i.e., pharmaceutical powder) is an effective index for controlling the physical properties of the finished tablet.

Randomized Clinical Trial of a Self-Adhering Flowable Composite for Class I Restorations: 2-Year Results.

PubMed

Sabbagh, J; Dagher, S; El Osta, N; Souhaid, P

2017-01-01

Objectives. To compare the clinical performances of a self-adhering resin composite and a conventional flowable composite with a self-etch bonding system on permanent molars. The influence of using rubber dam versus cotton roll isolation was also investigated. Materials and Methods. Patients aged between 6 and 12 years and presenting at least two permanent molars in need of small class I restorations were selected. Thirty-four pairs of restorations were randomly placed by the same operator. Fifteen patients were treated under rubber dam and nineteen using cotton rolls isolation and saliva ejector. They were evaluated according to the modified USPHS criteria at baseline, 6 months, and 1 and 2 years by two independent evaluators. Results. All patients attended the two-year recall. For all measured variables, there was no significant difference between rubber dam and cotton after 2 years of restoration with Premise Flowable or Vertise Flow ( p value > 0.05). The percentage of restorations scored alpha decreased significantly over time with Premise Flowable and Vertise Flow for marginal adaptation and surface texture as well as marginal discoloration while it did not vary significantly for color matching. After 2 years, Vertise Flow showed a similar behaviour to the Premise Flowable used with a self-adhesive resin system.

Comparative study between the radiopacity levels of high viscosity and of flowable composite resins, using digital imaging.

PubMed

Arita, Emiko S; Silveira, Gilson P; Cortes, Arthur R; Brucoli, Henrique C

2012-01-01

The development of countless types and trends of high viscosite and flowable composite resins, with different physical and chemical properties applicable to their broad use in dental clinics calls for further studies regarding their radiopacity level. The aim of this study was to evaluate the radiopacity levels of high viscosity and the flowable composite resins, using digital imaging. 96 composite resin discs 5 mm in diameter and 3 mm thick were radiographed and analyzed. The image acquisition system used was the Digora® Phosphor Storage System and the images were analyzed with the Digora software for Windows. The exposure conditions were: 70 kVp, 8 mA, and 0.2 s. The focal distance was 40 cm. The image densities were obtained with the pixel values of the materials in the digital image. Most of the high viscosity composite resins presented higher radiopacity levels than the flowable composite resins, with statistically significant differences between the trends and groups analyzed (P < 0.05). Among the high viscosity composite resins, Tetric®Ceram presented the highest radiopacity levels and Glacier® presented the lowest. Among the flowable composite resins, Tetric®Flow presented the highest radiopacity levels and Wave® presented the lowest.

A novel process route for the production of spherical SLS polymer powders

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

Schmidt, Jochen; Sachs, Marius; Blümel, Christina

2015-05-22

Currently, rapid prototyping gradually is transferred to additive manufacturing opening new applications. Especially selective laser sintering (SLS) is promising. One drawback is the limited choice of polymer materials available as optimized powders. Powders produced by cryogenic grinding show poor powder flowability resulting in poor device quality. Within this account we present a novel process route for the production of spherical polymer micron-sized particles of good flowability. The feasibility of the process chain is demonstrated for polystyrene e. In a first step polymer microparticles are produced by a wet grinding method. By this approach the mean particle size and the particlemore » size distribution can be tuned between a few microns and several 10 microns. The applicability of this method will be discussed for different polymers and the dependencies of product particle size distribution on stressing conditions and process temperature will be outlined. The comminution products consist of microparticles of irregular shape and poor powder flowability. An improvement of flowability of the ground particles is achieved by changing their shape: they are rounded using a heated downer reactor. The influence of temperature profile and residence time on the product properties will be addressed applying a viscous-flow sintering model. To further improve the flowability of the cohesive spherical polymer particles nanoparticles are adhered onto the microparticles’ surface. The improvement of flowability is remarkable: rounded and dry-coated powders exhibit a strongly reduced tensile strength as compared to the comminution product. The improved polymer powders obtained by the process route proposed open new possibilities in SLS processing including the usage of much smaller polymer beads.« less

Flowable composites for bonding orthodontic retainers.

PubMed

Tabrizi, Sama; Salemis, Elio; Usumez, Serdar

2010-01-01

To test the null hypothesis that there are no statistically significant differences between flowables and an orthodontic adhesive tested in terms of shear bond strength (SBS) and pullout resistance. To test the SBS of Light Bond, FlowTain, Filtek Supreme, and Tetric Flow were applied to the enamel surfaces of 15 teeth. Using matrices for application, each composite material was cured for 40 seconds and subjected to SBS testing. To test pullout resistance, 15 samples were prepared for each composite in which a wire was embedded; then the composite was cured for 40 seconds. Later, the ends of the wire were drawn up and tensile stress was applied until the resin failed. Findings were analyzed using an ANOVA and a Tukey HSD test. The SBS values for Light Bond, FlowTain, Filtek Supreme, and Tetric Flow were 19.0 +/- 10.9, 14.7 +/- 9.3, 22.4 +/- 16.3, and 16.8 +/- 11.8 MPa, respectively, and mean pullout values were 42.2 +/- 13.0, 24.0 +/- 6.9, 26.3 +/- 9.4, and 33.8 +/- 18.0 N, respectively. No statistically significant differences were found among the groups in terms of SBS (P > .05). On the other hand, Light Bond yielded significantly higher pullout values compared with the flowables Filtek Supreme and Flow-Tain (P < .01). However, there were no significant differences among the pullout values of flowables, nor between Light Bond and Tetric Flow (P > .05). The hypothesis is rejected. Light Bond yielded significantly higher pullout values compared with the flowables Filtek Supreme and FlowTain. However, flowable composites provided satisfactory SBS and wire pullout values, comparable to a standard orthodontic resin, and therefore can be used as an alternative for direct bonding of lingual retainers.

Evaluation of Microtensile Bond Strength and Microleakage of a Self-adhering Flowable Composite.

PubMed

Yuan, He; Li, Mingyang; Guo, Bin; Gao, Yuan; Liu, HongLing; Li, Jiyao

2015-12-01

To evaluate the microtensile bond strength (μTBS) and marginal sealing ability of a self-adhering flowable composite between dentin and composite interfaces, as well as the microleakage of Class V restorations. The occlusal thirds of 40 third molars were removed and randomly divided into 4 groups according to the applied adhesive: Adper Easy One (AEO, 3M ESPE), Clearfil SE Bond (CSEB, Kuraray), Prime & Bond NT (PBNT, Dentsply) and a self-adhering flowable composite (Dyad Flow, DF, Kerr). Filtek Flowable (3M ESPE) resin composite crowns were then built up in the first three groups; in group DF, composite crowns were built up without the application of an adhesive. Thirty stick-shaped microspecimens were prepared per group, 10 of which were used for morphological observation of bonded interfaces by scanning electron microscopy (SEM) after decalcification. The remaining microspecimens underwent microtensile bond strength testing and the failure mode was analyzed. Microleakage evaluation was performed on 10 premolars per group in which standardized box-shaped Class V cavities were prepared. After 500 thermocycles, the premolars were immersed in 1% methylene blue for 24 h, and three slices from each tooth were observed under a stereomicroscope and scored. Statistical analysis was performed using one-way ANOVA, Student-Newman-Keuls and chi-square tests. The PBNT group presented the highest μTBS values, followed by the CSEB and AEO groups, which did not differ significantly from each other. The DF group showed the lowest μTBS values. No significant differences in microleakage were observed among these four groups. Although individual usage of the self-adhering flowable composite showed the lowest bond strength, the same marginal sealing ability was observed as that of combining self-etching and etch-and-rinse adhesives with flowable composite.

Cutaneous wound healing after treatment with plant-derived human recombinant collagen flowable gel.

PubMed

Shilo, Shani; Roth, Sigal; Amzel, Tal; Harel-Adar, Tamar; Tamir, Eran; Grynspan, Frida; Shoseyov, Oded

2013-07-01

Chronic wounds, particularly diabetic ulcers, represent a main public health concern with significant costs. Ulcers often harbor an additional obstacle in the form of tunneled or undermined wounds, requiring treatments that can reach the entire wound tunnel, because bioengineered grafts are typically available only in a sheet form. While collagen is considered a suitable biodegradable scaffold material, it is usually extracted from animal and human cadaveric sources, and accompanied by potential allergic and infectious risks. The purpose of this study was to test the performance of a flowable gel made of human recombinant type I collagen (rhCollagen) produced in transgenic tobacco plants, indicated for the treatment of acute, chronic, and tunneled wounds. The performance of the rhCollagen flowable gel was tested in an acute full-thickness cutaneous wound-healing rat model and compared to saline treatment and two commercial flowable gel control products made of bovine collagen and cadaver human skin collagen. When compared to the three control groups, the rhCollagen-based gel accelerated wound closure and triggered a significant jumpstart to the healing process, accompanied by enhanced re-epithelialization. In a cutaneous full-thickness wound pig model, the rhCollagen-based flowable gel induced accelerated wound healing compared to a commercial product made of bovine tendon collagen. By day 21 post-treatment, 95% wound closure was observed with the rhCollagen product compared to 68% closure in wounds treated with the reference product. Moreover, rhCollagen treatment induced an early angiogenic response and induced a significantly lower inflammatory response than in the control group. In summary, rhCollagen flowable gel proved to be efficacious in animal wound models and is expected to be capable of reducing the healing time of human wounds.

Cutaneous Wound Healing After Treatment with Plant-Derived Human Recombinant Collagen Flowable Gel

PubMed Central

Roth, Sigal; Amzel, Tal; Harel-Adar, Tamar; Tamir, Eran; Grynspan, Frida; Shoseyov, Oded

2013-01-01

Chronic wounds, particularly diabetic ulcers, represent a main public health concern with significant costs. Ulcers often harbor an additional obstacle in the form of tunneled or undermined wounds, requiring treatments that can reach the entire wound tunnel, because bioengineered grafts are typically available only in a sheet form. While collagen is considered a suitable biodegradable scaffold material, it is usually extracted from animal and human cadaveric sources, and accompanied by potential allergic and infectious risks. The purpose of this study was to test the performance of a flowable gel made of human recombinant type I collagen (rhCollagen) produced in transgenic tobacco plants, indicated for the treatment of acute, chronic, and tunneled wounds. The performance of the rhCollagen flowable gel was tested in an acute full-thickness cutaneous wound-healing rat model and compared to saline treatment and two commercial flowable gel control products made of bovine collagen and cadaver human skin collagen. When compared to the three control groups, the rhCollagen-based gel accelerated wound closure and triggered a significant jumpstart to the healing process, accompanied by enhanced re-epithelialization. In a cutaneous full-thickness wound pig model, the rhCollagen-based flowable gel induced accelerated wound healing compared to a commercial product made of bovine tendon collagen. By day 21 post-treatment, 95% wound closure was observed with the rhCollagen product compared to 68% closure in wounds treated with the reference product. Moreover, rhCollagen treatment induced an early angiogenic response and induced a significantly lower inflammatory response than in the control group. In summary, rhCollagen flowable gel proved to be efficacious in animal wound models and is expected to be capable of reducing the healing time of human wounds. PMID:23259631

Method to study the effect of blend flowability on the homogeneity of acetaminophen.

PubMed

Llusá, Marcos; Pingali, Kalyana; Muzzio, Fernando J

2013-02-01

Excipient selection is key to product development because it affects their processability and physical properties, which ultimately affect the quality attributes of the pharmaceutical product. To study how the flowability of lubricated formulations affects acetaminophen (APAP) homogeneity. The formulations studied here contain one of two types of cellulose (Avicel 102 or Ceollus KG-802), one of three grades of Mallinckrodt APAP (fine, semi-fine, or micronized), lactose (Fast-Flo) and magnesium stearate. These components are mixed in a 300-liter bin blender. Blend flowability is assessed with the Gravitational Displacement Rheometer. APAP homogeneity is assessed with off-line NIR. Excluding blends dominated by segregation, there is a trend between APAP homogeneity and blend flow index. Blend flowability is affected by the type of microcrystalline cellulose and by the APAP grade. The preliminary results suggest that the methodology used in this paper is adequate to study of the effect of blend flow index on APAP homogeneity.

Fetal Bovine Collagen Matrix in the Treatment of a Full Thickness Burn Wound: A Case Report With Long-Term Follow-Up.

PubMed

Strong, Amy L; Bennett, Danielle K; Spreen, Elizabeth B; Adhvaryu, Dhaval V; Littleton, Jeffrey C; Mencer, Ernest J

2016-01-01

The treatment of full thickness skin wounds commonly associated with large burns continues to represent a challenging clinical entity. The current treatment for large TBSA burns is split thickness autologous skin grafting; however, this treatment often results in poor textural durability, hypertrophic scarring, and fibrotic contractures. In this case report, we describe our experience and long-term follow-up results after the application of fetal bovine collagen (FBC) matrix (PriMatrix, TEI Biosciences, Boston, MA) to burn wounds clinically assessed as full thickness that healed without the need for subsequent skin grafting. The patient presented with 25% TBSA burns and was debrided and covered with FBC on postburn day 7. By postoperative day 12, the patient had large areas of reepithelialization distributed throughout the wound bed. By postoperative day 26, the patient had significantly more areas of wound closure and was discharged. Reepithelialization and repigmentation continued, and long-term follow-up after 26 months demonstrated complete reepithelialization and nearly complete repigmentation, without the appearance of contractures or hypertrophic scarring. This case report highlights the use of FBC as a scaffold capable of dermal regeneration and spontaneous reepithelialization with an excellent long-term functional and cosmetic outcome.

Fetal Bovine Collagen Matrix in the Treatment of a Full Thickness Burn Wound: A Case Report With Long-Term Follow-Up

PubMed Central

Strong, Amy L.; Bennett, Danielle K.; Spreen, Elizabeth B.; Adhvaryu, Dhaval V.; Littleton, Jeffrey C.

2016-01-01

The treatment of full thickness skin wounds commonly associated with large burns continues to represent a challenging clinical entity. The current treatment for large TBSA burns is split thickness autologous skin grafting; however, this treatment often results in poor textural durability, hypertrophic scarring, and fibrotic contractures. In this case report, we describe our experience and long-term follow-up results after the application of fetal bovine collagen (FBC) matrix (PriMatrix, TEI Biosciences, Boston, MA) to burn wounds clinically assessed as full thickness that healed without the need for subsequent skin grafting. The patient presented with 25% TBSA burns and was debrided and covered with FBC on postburn day 7. By postoperative day 12, the patient had large areas of reepithelialization distributed throughout the wound bed. By postoperative day 26, the patient had significantly more areas of wound closure and was discharged. Reepithelialization and repigmentation continued, and long-term follow-up after 26 months demonstrated complete reepithelialization and nearly complete repigmentation, without the appearance of contractures or hypertrophic scarring. This case report highlights the use of FBC as a scaffold capable of dermal regeneration and spontaneous reepithelialization with an excellent long-term functional and cosmetic outcome. PMID:25494213

The effects of physical and chemical preprocessing on the flowability of corn stover

DOE PAGES

Crawford, Nathan C.; Nagle, Nick; Sievers, David A.; ...

2015-12-20

Continuous and reliable feeding of biomass is essential for successful biofuel production. However, the challenges associated with biomass solids handling are commonly overlooked. In this study, we examine the effects of preprocessing (particle size reduction, moisture content, chemical additives, etc.) on the flow properties of corn stover. Compressibility, flow properties (interparticle friction, cohesion, unconfined yield stress, etc.), and wall friction were examined for five corn stover samples: ground, milled (dry and wet), acid impregnated, and deacetylated. The ground corn stover was found to be the least compressible and most flowable material. The water and acid impregnated stovers had similar compressibilities.more » Yet, the wet corn stover was less flowable than the acid impregnated sample, which displayed a flow index equivalent to the dry, milled corn stover. The deacetylated stover, on the other hand, was the most compressible and least flowable examined material. However, all of the tested stover samples had internal friction angles >30°, which could present additional feeding and handling challenges. All of the ''wetted'' materials (water, acid, and deacetylated) displayed reduced flowabilities (excluding the acid impregnated sample), and enhanced compressibilities and wall friction angles, indicating the potential for added handling issues; which was corroborated via theoretical hopper design calculations. All of the ''wetted'' corn stovers require larger theoretical hopper outlet diameters and steeper hopper walls than the examined ''dry'' stovers.« less

The effects of physical and chemical preprocessing on the flowability of corn stover

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

Crawford, Nathan C.; Nagle, Nick; Sievers, David A.

Continuous and reliable feeding of biomass is essential for successful biofuel production. However, the challenges associated with biomass solids handling are commonly overlooked. In this study, we examine the effects of preprocessing (particle size reduction, moisture content, chemical additives, etc.) on the flow properties of corn stover. Compressibility, flow properties (interparticle friction, cohesion, unconfined yield stress, etc.), and wall friction were examined for five corn stover samples: ground, milled (dry and wet), acid impregnated, and deacetylated. The ground corn stover was found to be the least compressible and most flowable material. The water and acid impregnated stovers had similar compressibilities.more » Yet, the wet corn stover was less flowable than the acid impregnated sample, which displayed a flow index equivalent to the dry, milled corn stover. The deacetylated stover, on the other hand, was the most compressible and least flowable examined material. However, all of the tested stover samples had internal friction angles >30°, which could present additional feeding and handling challenges. All of the ''wetted'' materials (water, acid, and deacetylated) displayed reduced flowabilities (excluding the acid impregnated sample), and enhanced compressibilities and wall friction angles, indicating the potential for added handling issues; which was corroborated via theoretical hopper design calculations. All of the ''wetted'' corn stovers require larger theoretical hopper outlet diameters and steeper hopper walls than the examined ''dry'' stovers.« less

78 FR 38319 - Pesticide Maintenance Fee: Notice of Receipt of Requests to Voluntarily Cancel Certain Pesticide...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-26

... 100 Amber Herbicide Triasulfuron. 000100-00800 100 Ridomil Gold Bravo......... D-Alanine, N-(2,6- dimethylphenyl-N- (methoxyacetyl)-,methyl ester; Chlorothalonil. 000100-00848 100 Zorial Rapid 80 Herbicide...-00735 264 Sencor 4 Flowable Herbicide Metribuzin. 000264-00737 264 Bayleton 50% Dry Flowable Triadimefon...

[Improvement of powder flowability and hygroscopicity of traditional Chinese medicine extract by surface coating modification technology].

PubMed

Zeng, Rong-Gui; Jiang, Qie-Ying; Liao, Zheng-Gen; Zhao, Guo-Wei; Luo, Yun; Luo, Juan; Lv, Dan

2016-06-01

To study the improvement of powder flowability and hygroscopicity of traditional Chinese medicine extract by surface coating modification technology. The 1% hydrophobic silica nanoparticles were used as surface modifier, and andrographis extract powder was taken as a model drug. Three different techniques were used for coating model drugs, with angle of repose, compressibility, flat angle and cohesion as the comprehensive evaluation indexes for the powder flowability. The powder particle size and the size distribution were measured by Mastersizer 2000. FEI scanning electron microscope was used to observe the surface morphology and structure of the powder. The percentage of Si element on the powder surface was measured by energy dispersive spectrometer. The hygroscopicity of powder was determined by Chinese pharmacopoeia method. All of the three techniques can improve the flowability of powder extract. In particular, hygroscopicity of extract powder can also be improved by dispersion and then high-speed mixing, which can produce a higher percentage of Si element on the powder surface. The improvement principle may be correlated with a modifier adhered to the powder surface. Copyright© by the Chinese Pharmaceutical Association.

Two-year clinical comparison of a flowable-type nano-hybrid composite and a paste-type composite in posterior restoration.

PubMed

Hirata-Tsuchiya, Shizu; Yoshii, Shinji; Ichimaru-Suematsu, Miki; Washio, Ayako; Saito, Noriko; Urata, Mariko; Hanada, Kaori; Morotomi, Takahiko; Kitamura, Chiaki

2017-08-01

The purpose of the present study was to compare the clinical efficacy between a flowable-type nano-hybrid composite and a paste-type composite for posterior restoration. Of 62 posterior teeth in 33 patients (mean age: 34.1 years), 31 were filled with a paste-type composite (Heliomolar [HM] group), and another 31 with a flowable nano-hybrid composite (MI FIL [MI] group). Clinical efficacy was evaluated at 2 years after the restoration. There were no differences for retention, surface texture deterioration, anatomical form change, deterioration of marginal adaptation, and secondary caries, while a statistical difference was found for marginal discoloration, which was significantly greater in the HM group (P < 0.05). Furthermore, color matching in the MI group was superior to that in the HM group immediately after the restoration throughout the study period. The present 2-year clinical evaluation of different composites showed that the flowable nano-hybrid composite could be an effective esthetic material for posterior restoration. © 2016 John Wiley & Sons Australia, Ltd.

Effects of calcium hydroxide addition on the physical and chemical properties of a calcium silicate-based sealer.

PubMed

Kuga, Milton Carlos; Duarte, Marco Antonio Hungaro; Sant'anna-Júnior, Arnaldo; Keine, Kátia Cristina; Faria, Gisele; Dantas, Andrea Abi Rached; Guiotti, Flávia Angélica

2014-06-01

Recently, various calcium silicate-based sealers have been introduced for use in root canal filling. The MTA Fillapex is one of these sealers, but some of its physicochemical properties are not in accordance with the ISO requirements. The aim of this study was to evaluate the flowability, pH level and calcium release of pure MTA Fillapex (MTAF) or containing 5% (MTAF5) or 10% (MTAF10) calcium hydroxide (CH), in weight, in comparison with AH Plus sealer. The flowability test was performed according to the ISO 6876:2001 requirements. For the pH level and calcium ion release analyses, the sealers were placed individually (n=10) in plastic tubes and immersed in deionized water. After 24 hours, 7 and 14 days, the water in which each specimen had been immersed was evaluated to determine the pH level changes and calcium released. Flowability, pH level and calcium release data were analyzed statistically by the ANOVA test (α=5%). In relation to flowability: MTAF>AH Plus>MTAF5>MTAF10. In relation to the pH level, for 24 h: MTAF5=MTAF10=MTAF>AH Plus; for 7 and 14 days: MTAF5=MTAF10>MTAF>AH Plus. For the calcium release, for all periods: MTAF>MTAF5=MTAF10>AH Plus. The addition of 5% CH to the MTA Fillapex (in weight) is an alternative to reduce the high flowability presented by the sealer, without interfering in its alkalization potential.

Sealing ability of lateral condensation, thermoplasticized gutta-percha and flowable gutta-percha obturation techniques: A comparative in vitro study.

PubMed

Kumar, Nallkkapalayam Somasundaram Mohan; Prabu, P S; Prabu, Neethika; Rathinasamy, Shobana

2012-08-01

To evaluate and compare the sealing ability between the clod lateral condensation, thermoplasticized gutta-percha, and flowable gutta-percha obturation technique, under a stereomicroscope at ×40 magnification. Sixty single rooted teeth were selected and canals were shaped with K3 NiTi files. Irrigation was performed with 5.25% NaOCl and 17% ethylenediaminetetraacetic acid (EDTA). The teeth were then separated into three groups depending on the type of obturation technique: Group A, obturated using the lateral condensation technique and AH Plus sealer; Group B, obturated with thermoplasticized gutta-percha tech (Obtura III Max) and AH Plus sealer; and Group C, obturated using flowable gutta-percha technique (GuttaFlow). After storing the teeth in 100% humidity for 7 days at 37°C, the roots of the teeth were sectioned at five levels. The sections were then observed under a stereomicroscope at ×40 magnification and the images were analyzed for area of voids (AV) and frequency of voids. The data were statistically analyzed using the SPSS version 17 software. The 95% confidence intervals (CI) were calculated. One-way analysis of variance with post hoc test and non-parametric Mann-Whitney U test were carried out to compare the means. The lowest mean of AV was recorded in the thermoplasticized gutta-percha (Obtura III Max) group [1.0% (95% CI=0.5-1.5)]. This was statistically and significantly different from flowable gutta-percha (GuttaFlow) group [3.0% (95% CI=2.1-3.9)]. There was no significant difference between the thermoplasticized gutta-percha group and lateral condensation group [1.6% (95% CI=1.0-2.2)] with regard to the AV, but there was a statistically significant difference between the lateral condensation and flowable gutta-percha groups. The flowable gutta-percha group showed the maximum number of voids [56% (95% CI=48-64)], which was significantly higher than those in the lateral condensation [26% (95% CI=19-34)] and thermoplasticized gutta-percha [15% (95% CI=10-21)] groups. The thermoplasticized gutta-percha technique (Obtura III Max) had better adaptability to the canal walls when compared to the flowable gutta-percha (GuttaFlow) obturation and lateral condensation techniques.

Fragipan Horizon Fragmentation in Slaking Experiments with Amendment Materials and Ryegrass Root Tissue Extracts

PubMed Central

Karathanasis, A. D.; Murdock, L. W.; Matocha, C. J.; Grove, J.; Thompson, Y. L.

2014-01-01

Slaking experiments were conducted of fragipan clods immersed in solutions of poultry manure, aerobically digested biosolid waste (ADB), fluidized bed combustion byproduct (FBC), D-H2O, CaCO3, NaF, Na-hexa-metaphosphate, and ryegrass root biomass. The fragipan clods were sampled from the Btx horizon of an Oxyaquic Fragiudalf in Kentucky. Wet sieving aggregate analysis showed significantly better fragmentation in the NaF, Na-hexa-metaphosphate, and ryegrass root solutions with a mean weight diameter range of 15.5–18.8 mm compared to the 44.2–47.9 mm of the poultry manure, ADB, and FBC treatments. Dissolved Si, Al, Fe, and Mn levels released in solution were ambiguous. The poor efficiency of the poultry manure, ADB, and FBC treatments was attributed to their high ionic strength, while the high efficiency of the NaF, Na-hexa-metaphosphate, and rye grass root solutions to their high sodium soluble ratio (SSR). A slaking mechanism is proposed suggesting that aqueous solutions with high SSR penetrate faster into the fragipan capillaries and generate the critical swelling pressure and shearing stress required to rupture the fragipan into several fragments. Additional fragmentation occurs in a followup stage during which potential Si, Al, Fe, and Mn binding agents may be released into solution. Field experiments testing these findings are in progress. PMID:25254233

Influence of final baking technologies in partially baked frozen gluten-free bread quality.

PubMed

Aguilar, Núria; Albanell, Elena; Miñarro, Begoña; Gallardo, Joan; Capellas, Marta

2015-03-01

The effect of final baking in convection oven (FBC), microwave oven (FBM), and microwave oven with susceptor packaging material (FBMS) on partially baked (PB) frozen gluten-free bread characteristics was investigated. Specific volume and crust color of loaves were measured at day 0. Bread moisture, water activity, and crumb and crust texture (at 15, 45, and 90 min after baking) were analyzed at day 0 and after 28 d of frozen storage (-18 °C). Volatile compounds from breads baked in convection oven or microwave oven with susceptor packaging material were also evaluated. Bread finally baked in convection oven or in microwave oven with susceptor packaging increased crust browning. Crumb and roll hardness increased with time after final baking (measured at 15, 45, 90 min) and after 28 d of frozen storage. Bread finally baked in microwave oven was the hardest, due to high water losses. At day 0, bread finally baked in convection oven had softer crumb than bread finally baked in microwave oven with susceptor packaging but, after 28 d of frozen storage, there were no differences between them. Moreover, FBC and FBMS rendered gluten-free breads that could not be distinguished in a triangular test and had the same volatile compounds profile. In conclusion, FBMS could be an alternative to FBC. © 2015 Institute of Food Technologists®

FIRST BEAM TESTS OF THE APS MBA UPGRADE ORBIT FEEDBACK CONTROLLER

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

Sereno, N. S.; Arnold, N.; Brill, A.

The new orbit feedback system required for the APS multi-bend acromat (MBA) ring must meet challenging beam stability requirements. The AC stability requirement is to correct rms beam motion to 10 % the rms beam size at the insertion device source points from 0.01 to 1000 Hz. The vertical plane represents the biggest challenge for AC stability which is required to be 400 nm rms for a 4 micron vertical beam size. In addition long term drift over a period of 7 days is required to be 1 micron or less at insertion de- vice BPMs and 2 microns formore » arc bpms. We present test re- sults of theMBA prototype orbit feedback controller (FBC) in the APS storage ring. In this test, four insertion device BPMs were configured to send data to the FBC for process- ing into four fast corrector setpoints. The configuration of four bpms and four fast correctors creates a 4-bump and the configuration of fast correctors is similar to what will be implemented in the MBA ring. We report on performance benefits of increasing the sampling rate by a factor of 15 to 22.6 kHz over the existing APS orbit feedback system, lim- itations due to existing storage ring hardware and extrapo- lation to theMBA orbit feedback design. FBC architecture, signal flow and processing design will also be discussed.« less

Artificial neural network modeling of DDGS flowability with varying process and storage parameters

USDA-ARS?s Scientific Manuscript database

Neural Network (NN) modeling techniques were used to predict flowability behavior in distillers dried grains with solubles (DDGS) prepared with varying CDS (10, 15, and 20%, wb), drying temperature (100, 200, and 300°C), cooling temperature (-12, 0, and 35°C) and cooling time (0 and 1 month) levels....

Flowability of granular materials with industrial applications - An experimental approach

NASA Astrophysics Data System (ADS)

Torres-Serra, Joel; Romero, Enrique; Rodríguez-Ferran, Antonio; Caba, Joan; Arderiu, Xavier; Padullés, Josep-Manel; González, Juanjo

2017-06-01

Designing bulk material handling equipment requires a thorough understanding of the mechanical behaviour of powders and grains. Experimental characterization of granular materials is introduced focusing on flowability. A new prototype is presented which performs granular column collapse tests. The device consists of a channel whose design accounts for test inspection using visualization techniques and load measurements. A reservoir is attached where packing state of the granular material can be adjusted before run-off to simulate actual handling conditions by fluidisation and deaeration of the pile. Bulk materials on the market, with a wide range of particle sizes, can be tested with the prototype and the results used for classification in terms of flowability to improve industrial equipment selection processes.

[Surface roughness and gloss of novel flowable composites after polishing and simulated brushing wear].

PubMed

Wang, R L; Yuan, C Y; Pan, Y X; Tian, F C; Wang, Z H; Wang, X Y

2017-04-09

Objective: To investigate surface properties of novel flowable composites after polishing and simulated brushing wear, compared to their pasty counterpart. Methods: Composites employed in this study were: three flowable composites (A1: Clearfil Majesty ES Flow; B1: Beautifil Flow Plus F00; C1: Filtek Bulk Fill) and three paste composites (A2: Clearfil Majesty; B2: Beautifil; C2: Filtek Z350. Eleven disk-shaped specimens were made for each material. The specimens were cured, then subjected to sandpaper finishing for 20 s, one-step polishing for 30 s, finally subjected to simulated brushing for 10 000 cycles. Surface roughness and glossiness were measured before finishing, after finishing, after polishing, after 5 000 brushing cycles and after 10 000 brushing cycles, respectively. Data obtained were analyzed using two-way ANOVA method. Scanning electron microscope was employed to examine the microscopic appearance of each material. Results: Surface roughness (0.11~0.22 μm) and glossiness (74.25~86.48 GU) of each material were similar after one-step polishing. After brushing simulation, roughness increased significantly and glossiness decreased significantly for each material ( P< 0.05). Group A1 presented the best gloss ([50.68±1.58] GU) after final wear ( P< 0.05). Flowable composites of group A1 and B1 tested in the present setup showed better surface properties compared to their pasty counterpart (group A2 and B2). Conclusions: Within the limit of this study, flowable composites tested in the present research can obtain similar surface polish or even better than the paste composite counterpart.

Fracture resistance of endodontically treated teeth restored with a bulkfill flowable material and a resin composite

PubMed Central

Isufi, Almira; Plotino, Gianluca; Grande, Nicola Maria; Ioppolo, Pietro; Testarelli, Luca; Bedini, Rossella; Al-Sudani, Dina; Gambarini, Gianluca

2016-01-01

Summary Aim To determine and compare the fracture resistance of endodontically treated teeth restored with a bulk fill flowable material (SDR) and a traditional resin composite. Methods Thirty maxillary and 30 mandibular first molars were selected based on similar dimensions. After cleaning, shaping and filling of the root canals and adhesive procedures, specimens were assigned to 3 subgroups for each tooth type (n=10): Group A: control group, including intact teeth; Group B: access cavities were restored with a traditional resin composite (EsthetX; Dentsply-Italy, Rome, Italy); Group C: access cavities were restored with a bulk fill flowable composite (SDR; Dentsply-Italy), except 1.5 mm layer of the occlusal surface that was restored with the same resin composite as Group B. The specimens were subjected to compressive force in a material static-testing machine until fracture occurred, the maximum fracture load of the specimens was measured (N) and the type of fracture was recorded as favorable or unfavorable. Data were statistically analyzed with one-way analysis of variance (ANOVA) and Bonferroni tests (P<0.05). Results No statistically significant differences were found among groups (P<0.05). Fracture resistance of endodontically treated teeth restored with a traditional resin composite and with a bulk fill flowable composite (SDR) was similar in both maxillary and mandibular molars and showed no significant decrease in fracture resistance compared to intact specimens. Conclusions No significant difference was observed in the mechanical fracture resistance of endodontically treated molars restored with traditional resin composite restorations compared to bulk fill flowable composite restorations. PMID:27486505

Effects of calcium hydroxide addition on the physical and chemical properties of a calcium silicate-based sealer

PubMed Central

KUGA, Milton Carlos; DUARTE, Marco Antonio Hungaro; SANT'ANNA-JÚNIOR, Arnaldo; KEINE, Kátia Cristina; FARIA, Gisele; DANTAS, Andrea Abi Rached; GUIOTTI, Flávia Angélica

2014-01-01

Recently, various calcium silicate-based sealers have been introduced for use in root canal filling. The MTA Fillapex is one of these sealers, but some of its physicochemical properties are not in accordance with the ISO requirements. Objective The aim of this study was to evaluate the flowability, pH level and calcium release of pure MTA Fillapex (MTAF) or containing 5% (MTAF5) or 10% (MTAF10) calcium hydroxide (CH), in weight, in comparison with AH Plus sealer. Material and Methods The flowability test was performed according to the ISO 6876:2001 requirements. For the pH level and calcium ion release analyses, the sealers were placed individually (n=10) in plastic tubes and immersed in deionized water. After 24 hours, 7 and 14 days, the water in which each specimen had been immersed was evaluated to determine the pH level changes and calcium released. Flowability, pH level and calcium release data were analyzed statistically by the ANOVA test (α=5%). Results In relation to flowability: MTAF>AH Plus>MTAF5>MTAF10. In relation to the pH level, for 24 h: MTAF5=MTAF10=MTAF>AH Plus; for 7 and 14 days: MTAF5=MTAF10>MTAF>AH Plus. For the calcium release, for all periods: MTAF>MTAF5=MTAF10>AH Plus. Conclusions The addition of 5% CH to the MTA Fillapex (in weight) is an alternative to reduce the high flowability presented by the sealer, without interfering in its alkalization potential. PMID:25025558

Fracture resistance of endodontically treated teeth restored with a bulkfill flowable material and a resin composite.

PubMed

Isufi, Almira; Plotino, Gianluca; Grande, Nicola Maria; Ioppolo, Pietro; Testarelli, Luca; Bedini, Rossella; Al-Sudani, Dina; Gambarini, Gianluca

2016-01-01

To determine and compare the fracture resistance of endodontically treated teeth restored with a bulk fill flowable material (SDR) and a traditional resin composite. Thirty maxillary and 30 mandibular first molars were selected based on similar dimensions. After cleaning, shaping and filling of the root canals and adhesive procedures, specimens were assigned to 3 subgroups for each tooth type (n=10): Group A: control group, including intact teeth; Group B: access cavities were restored with a traditional resin composite (EsthetX; Dentsply-Italy, Rome, Italy); Group C: access cavities were restored with a bulk fill flowable composite (SDR; Dentsply-Italy), except 1.5 mm layer of the occlusal surface that was restored with the same resin composite as Group B. The specimens were subjected to compressive force in a material static-testing machine until fracture occurred, the maximum fracture load of the specimens was measured (N) and the type of fracture was recorded as favorable or unfavorable. Data were statistically analyzed with one-way analysis of variance (ANOVA) and Bonferroni tests (P<0.05). No statistically significant differences were found among groups (P<0.05). Fracture resistance of endodontically treated teeth restored with a traditional resin composite and with a bulk fill flowable composite (SDR) was similar in both maxillary and mandibular molars and showed no significant decrease in fracture resistance compared to intact specimens. No significant difference was observed in the mechanical fracture resistance of endodontically treated molars restored with traditional resin composite restorations compared to bulk fill flowable composite restorations.

Investigation of the effect of impeller speed on granules formed using a PMA-1 high shear granulator.

PubMed

Logan, R; Briens, L

2012-11-01

Impeller speed was varied from 300 to 1500 rpm during the wet high shear granulation of a placebo formulation using a new vertical shaft PharmaMATRIX-1 granulator. The resulting granules were extensively analysed for differences caused by the varying impeller speed with emphasis on flowability. Microscopy showed that initial granules were formed primarily from microcrystalline cellulose at all tested impeller speeds. At low impeller speed of 300 rpm in the "bumpy" flow regime, forces from the impeller were insufficient to incorporate all the components of the formulation into the granules and to promote granule growth to a size that significantly improved flowability. The "roping" flow regime at higher impeller speeds promoted granule growth to a median particle size of at least 100 µm that improved the flowability of the mixture. Particle size distribution measurements and advanced indicators based on avalanching behavior, however, showed that an impeller speed of 700 rpm produced the largest fraction of optimal granules with the best flowability potential. This impeller speed allowed good development of "roping" flow for sufficient mixing, collision rates and kinetic energy for collisions while minimizing excessive centrifugal forces that promote buildup around the bowl perimeter.

Evaluation of the polymerization shrinkage of experimental flowable composite resins through optical coherence tomography

NASA Astrophysics Data System (ADS)

Carneiro, Vanda S. M.; Mota, Cláudia C. B. O.; Souza, Alex F.; Cajazeira, Marlus R. R.; Gerbi, Marleny E. M. M.; Gomes, Anderson S. L.

2018-02-01

This study evaluated the polymerization shrinkage of two experimental flowable composite resins (CR) with different proportions of Urethane dimethacrylate (UDMA)/triethylene glycol dimethacrylate (TEGDMA) monomers in the organic matrix (50:50 and 60:40, respectively). A commercially available flowable CR, Tetric N-Flow (Ivoclair Vivadent, Liechtenstein, Germany), was employed as the control group. The resins were inserted in a cylindrical teflon mold (7 mm diameter, 0.6 mm height) and scanned with OCT before photoactivation, immediately after and 15 minutes after light-curing (Radii-Cal, SDI, Australia, 1,200 mW/cm2 ) exposure. A Callisto SD-OCT system (Thorlabs Inc, USA), operating at 930 nm central wavelength was employed for imaging acquisition. Cross-sectional OCT images were captured with 8 mm transverse scanning (2000x512 matrix), and processed by the ImageJ software, for comparison between the scanning times and between groups. Pearson correlation showed significant shrinkage for all groups in each time analyzed. Kruskal-Wallis test showed greater polymerization shrinkage for the 50:50 UDMA/TEGDMA group (p=0.001), followed by the control group (p=0.018). TEGDMA concentration was proportionally related to the polymerization shrinkage of the flowable composite resins.

Flowability of lignocellusic biomass powders: influence of torrefaction intensity

NASA Astrophysics Data System (ADS)

Pachón-Morales, John; Colin, Julien; Pierre, Floran; Champavert, Thibaut; Puel, François; Perré, Patrick

2017-06-01

The poor flowability of powders produced from raw lignocellulosic biomass may be an economically issue for the production of second-generation biofuels. Torrefaction is a pre-treatment step of the gasification process that improves the physical characteristics of biomass by making it more coal-like. Particularly, the loss of resilience allows a reduction of the grinding energy consumption and is likely to improve the flow behaviour of woody powders. In this study, we investigated the effect of particle size and shape distribution on flow properties (unconfined yield stress and flowability factor) of powder from raw and torrefied biomass (Picea abies). Several intensities of torrefaction were tested, and its extent was quantified by the global mass loss, chosen as synthetic indicator of torrefaction intensity (its accounts for both the temperature level and the residence time). The intensity of torrefaction shifts the particle size distribution towards smaller sizes. An effect on the circularity and aspect ratio was also observed. A strong, positive correlation was obtained between the measured flowability of biomass powders at different consolidation stresses and the intensity of heat treatment. These results confirm the interest of torrefaction as a pre-treatment step and aim to provide new knowledge on rheological properties of biomass powders.

Food powders flowability characterization: theory, methods, and applications.

PubMed

Juliano, Pablo; Barbosa-Cánovas, Gustavo V

2010-01-01

Characterization of food powders flowability is required for predicting powder flow from hoppers in small-scale systems such as vending machines or at the industrial scale from storage silos or bins dispensing into powder mixing systems or packaging machines. This review covers conventional and new methods used to measure flowability in food powders. The method developed by Jenike (1964) for determining hopper outlet diameter and hopper angle has become a standard for the design of bins and is regarded as a standard method to characterize flowability. Moreover, there are a number of shear cells that can be used to determine failure properties defined by Jenike's theory. Other classic methods (compression, angle of repose) and nonconventional methods (Hall flowmeter, Johanson Indicizer, Hosokawa powder tester, tensile strength tester, powder rheometer), used mainly for the characterization of food powder cohesiveness, are described. The effect of some factors preventing flow, such as water content, temperature, time consolidation, particle composition and size distribution, is summarized for the characterization of specific food powders with conventional and other methods. Whereas time-consuming standard methods established for hopper design provide flow properties, there is yet little comparative evidence demonstrating that other rapid methods may provide similar flow prediction.

A risk management model for familial breast cancer: A new application using Fuzzy Cognitive Map method.

PubMed

Papageorgiou, Elpiniki I; Jayashree Subramanian; Karmegam, Akila; Papandrianos, Nikolaos

2015-11-01

Breast cancer is the most deadly disease affecting women and thus it is natural for women aged 40-49 years (who have a family history of breast cancer or other related cancers) to assess their personal risk for developing familial breast cancer (FBC). Besides, as each individual woman possesses different levels of risk of developing breast cancer depending on their family history, genetic predispositions and personal medical history, individualized care setting mechanism needs to be identified so that appropriate risk assessment, counseling, screening, and prevention options can be determined by the health care professionals. The presented work aims at developing a soft computing based medical decision support system using Fuzzy Cognitive Map (FCM) that assists health care professionals in deciding the individualized care setting mechanisms based on the FBC risk level of the given women. The FCM based FBC risk management system uses NHL to learn causal weights from 40 patient records and achieves a 95% diagnostic accuracy. The results obtained from the proposed model are in concurrence with the comprehensive risk evaluation tool based on Tyrer-Cuzick model for 38/40 patient cases (95%). Besides, the proposed model identifies high risk women by calculating higher accuracy of prediction than the standard Gail and NSAPB models. The testing accuracy of the proposed model using 10-fold cross validation technique outperforms other standard machine learning based inference engines as well as previous FCM-based risk prediction methods for BC. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Options for Hardening FinFETS with Flowable Oxide Between Fins

DTIC Science & Technology

2017-03-01

thus hardening by process is needed. Using the methodology of CV measurements on inexpensive experimental blanket oxides we have determined options...NY 10598 Abstract: A methodology using radiation-induced charge measurements by CV techniques on blanket oxides is shown to aid in the choice...of process options for hardening FinFETs. Net positive charge in flowable oxides was reduced by 50 % using a simple non -intrusive process change

Fractal aspects of the flow and shear behaviour of free-flowable particle size fractions of pharmaceutical directly compressible excipient sorbitol.

PubMed

Hurychová, Hana; Lebedová, Václava; Šklubalová, Zdenka; Dzámová, Pavlína; Svěrák, Tomáš; Stoniš, Jan

Flowability of powder excipients is directly influenced by their size and shape although the granulometric influence of the flow and shear behaviour of particulate matter is not studied frequently. In this work, the influence of particle size on the mass flow rate through the orifice of a conical hopper, and the cohesion and flow function was studied for four free-flowable size fractions of sorbitol for direct compression in the range of 0.080-0.400 mm. The particles were granulometricaly characterized using an optical microscopy; a boundary fractal dimension of 1.066 was estimated for regular sorbitol particles. In the particle size range studied, a non-linear relationship between the mean particle size and the mass flow rate Q10 (g/s) was detected having amaximum at the 0.245mm fraction. The best flow properties of this fraction were verified with aJenike shear tester due to the highest value of flow function and the lowest value of the cohesion. The results of this work show the importance of the right choice of the excipient particle size to achieve the best flow behaviour of particulate material.Key words: flowability size fraction sorbitol for direct compaction Jenike shear tester fractal dimension.

First branchial cleft anomalies: presentation, variability and safe surgical management.

PubMed

Magdy, Emad A; Ashram, Yasmine A

2013-05-01

First branchial cleft (FBC) anomalies are uncommon. The aim of this retrospective clinical study is to describe our experience in dealing with these sporadically reported lesions. Eighteen cases presenting with various FBC anomalies managed surgically during an 8-year period at a tertiary referral medical institution were included. Ten were males (56 %) and eight females (44 %) with age range 3-18 years. Anomaly was right-sided in 12 cases (67 %). None were bilateral. Nine patients (50 %) had prior abscess incision and drainage procedures ranging from 1 to 9 times. Two also had previous unsuccessful surgical excisions. Clinical presentations included discharging tract openings in external auditory canal/conchal bowl (n = 9), periauricular (n = 6), or upper neck (n = 4); cystic postauricular, parotid or upper neck swellings (n = 5); and eczematous scars (n = 9). Three distinct anatomical types were encountered: sinuses (n = 7), fistulas (n = 6), and cysts (n = 5). Complete surgical excision required superficial parotidectomy in 11 patients (61 %). Anomaly was deep to facial nerve (FN) in three cases (17 %), in-between its branches in two (11 %) and superficial (but sometimes adherent to the nerve) in remaining cases (72 %). Continuous intraoperative electrophysiological FN monitoring was used in all cases. Two cases had postoperative temporary lower FN paresis that recovered within 2 months. No further anomaly manifestation was observed after 49.8 months' mean postoperative follow-up (range 10-107 months). This study has shown that awareness of different presentations and readiness to identify and protect FN during surgery is essential for successful management of FBC anomalies. Intraoperative electrophysiological FN monitoring can help in that respect.

Novel use of a flowable collagen-glycosaminoglycan matrix (Integra™ Flowable Wound Matrix) combined with percutaneous cannula scar tissue release in treatment of post-burn malfunction of the hand--A preliminary 6 month follow-up.

PubMed

Hirche, C; Senghaas, A; Fischer, S; Hollenbeck, S T; Kremer, T; Kneser, U

2016-02-01

Long-term function following severe burns to the hand may be poor secondary to scar adhesions to the underlying tendons, webspaces, and joints. In this pilot study, we report the feasibility of applying a pasty dermal matrix combined with percutaneous cannula teno- and adhesiolysis. In this 6 month follow-up pilot study, we included eight hands in five patients with hand burns undergoing minimal-invasive, percutaneous cannula adhesiolysis and injection of INTEGRA™ Flowable Wound Matrix for a pilot study of this new concept. The flowable collagen-glycosaminoglycan wound matrix (FCGWM) was applied with a buttoned 2mm cannula to induce formation of a neo-gliding plane. Post treatment follow-up was performed to assess active range of motion (AROM), grip strength, Disabilities of the Arm, Shoulder and Hand (DASH) score, Vancouver Scar Scale (VSS) and quality of life Short-Form (SF)-36 questionnaire. No complications were detected associated with the treatment of FCGWM injection. The mean improvement (AROM) at 6 months was 30.6° for digits 2-5. The improvement in the DASH score was a mean of 9 points out of 100. The VSS improved by a mean of 2 points out of 14. The study demonstrates the feasibility and safety of percutaneous FCGWM for dermal augmentation after burn. Results from this pilot study show improvements in AROM for digits 2-5, functional scores from the patient's perspective (DASH) and scar quality (VSS). The flowable form of established INTEGRA™ wound matrix offers the advantage of minimal-invasive injection after scar release in the post-burned hand with a reduction in the risk of postsurgical re-scarring. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

Mechanical properties and three-body wear of dental restoratives and their comparative flowable materials.

PubMed

Schultz, Sabine; Rosentritt, Martin; Behr, Michael; Handel, Gerhard

2010-01-01

To compare wear performance and resistance to crack propagation (K1C) of commercial restorative materials and their flowable variations. A potential correlation between three-body wear and fracture toughness, modulus of elasticity, fracture work, Vickers hardness, and filler content was investigated. Seven restoratives (five composites, one ormocer, and one compomer) and their corresponding flowable materials were used to determine and compare the three-body wear with a bolus of millet-seed shells and rice food (Willytec). The wear characteristics were measured by profilometry after 50,000, 100,000, 150,000, and 200,000 loading cycles. The fracture toughness value, K1C (MPam1/2), for each single-edged notched specimen was measured in a three-point bending test (universal testing machine 1446, Zwick). Fracture work and modulus of elasticity were calculated from the load curves. Vickers hardness was measured (HV hardness tester, Zwick) according to DIN 50133. The veneering composite Sinfony (3M ESPE) was used as a reference material. Heavily filled composites experienced less wear than their flowable variations. The nanofiller composites revealed better wear results than hybrid composites, compomers, and ormocers. After 200,000 load cycles, the lowest wear rates were detected for Grandio (14 microm; Voco), and the highest mean values were found for Dyract AP (104 microm; Dentsply DeTrey). The values for fracture toughness (K1C) ranged from 0.82 to 3.64 MPam1/2. Highest K1C data was exhibited by the nanocomposite Nanopaq (Schutz Dental). All tested restorative materials exhibited higher fracture toughness than their low-viscosity variations. The wear resistance of the newer generation composites with incorporated nanofiller or microfiller particles increased to a high extent. Flowables show less resistance against wear and crack propagation because of their lower filler content. The reduced mechanical properties limit their use as a restorative to small noncontact, low-stress clinical situations.

Microleakage and penetration depth of different fissure sealant materials after cyclic thermo-mechanic and brushing simulation.

PubMed

Hatirli, Hüseyin; Yasa, Bilal; Yasa, Elif

2018-01-30

The aim of the study was to evaluate microleakage and the penetration-depths of different fissure-sealant materials applied with/without enameloplasty after cyclic aging. One-hundred-sixty mandibular molars were divided into non-invasive and enameloplasty preparation groups and eight material subgroups, including: flowable composites (microhyrid, nanohybrid, and nanofilled), three resin-based (unfilled, filled, and highly-filled), a giomer-based, and a glass-ionomer-based fissure sealant. Specimens were subjected to two-year cyclic chewing and brushing simulation. After 5% basic-fuchsin dye penetration, specimens were sectioned and scored under stereomicroscope. Kruskal-Wallis statistical data showed that preparation type significantly affected the penetration of all tested materials (p<0.05), but not significantly affected microleakage (p>0.05). Flowable composites showed the best and the glass-ionomer-based sealant showed the worst penetration and microleakage. Slight preparation of fissures is not important in microleakage. However, enameloplasty significantly enhanced the depth of penetration of the sealants. Flowable composites offer promising results at the fissure sealing.

Characteristics of low polymerization shrinkage flowable resin composites in newly-developed cavity base materials for bulk filling technique.

PubMed

Nitta, Keiko; Nomoto, Rie; Tsubota, Yuji; Tsuchikawa, Masuji; Hayakawa, Tohru

2017-11-29

The purpose of this study was to evaluate polymerization shrinkage and other physical properties of newly-developed cavity base materials for bulk filling technique, with the brand name BULK BASE (BBS). Polymerization shrinkage was measured according to ISO/FDIS 17304. BBS showed the significantly lowest polymerization shrinkage and significantly higher depth of cure than conventional flowable resin composites (p<0.05). The Knoop hardness, flexural strength and elastic modulus of that were significantly lower than conventional flowable resin composites (p<0.05). BBS had the significantly greatest filler content (p<0.05). SEM images of the surface showed failure of fillers. The lowest polymerization shrinkage was due to the incorporation of a new type of low shrinkage monomer, which has urethane moieties. There were no clear correlations between inorganic filler contents and polymerization shrinkage, flexural strength and elastic modulus. In conclusion, the low polymerization shrinkage of BBS will be useful for cavity treatment in dental clinics.

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

Wheeler, P.A.; Patel, N.M.; Painter, A.

Energy recovery from municipal solid waste (MSW) is an important component of an integrated waste management strategy. Waste management programs which remove or recover materials for recycling are particularly suited for considering the option of energy recovery via fluidized bed combustion (FBC). The last few years have seen growing interest in the application of FBC technology to the MSW treatment/disposal problem. This paper reviews and reports on the world-wide experience in fluidized bed combustion of MSW focusing particularly on the types and scales of the systems in operation in Japan and Scandinavia. In addition the paper also reports on themore » development of an energy from waste project employing circulating fluidized bed technology that is proposed for a local municipality in the UK. Japan currently has over 100 bubbling bed units in operation firing on 100% MSW; the technology is firmly established at scales of operation up to 160,000t/y (the largest single unit operates at 6.25t/h). The bubbling bed units accept MSW which has undergone only minimal pre-processing -- the waste is shredded to a nominal 300mm size fraction before being introduced to the furnace. There are distinct (combustion control) advantages to further processing of the waste stream prior to combustion. The Scandinavian countries in particular have been the prime movers in pioneering this technology to work in combination with circulating fluidized bed systems. Currently 2 units are in operation cofiring pre-processed MSW with a range of other biofuels. A number of FBC units firing 100% MSW are currently in the planning or construction stage around the world; they seem set to secure an increased market share particularly at the smaller scale of operation (up to about 200,000t/y).« less

Effect of Salivary pH on Color Stability of Different Flowable Composites - A Prospective In-vitro Study.

PubMed

Batra, Renu; Kataria, Pratik; Kapoor, Sonali

2016-10-01

Scientifically and clinically there has been lot of development in the field of aesthetic dentistry. However, there is limited or restricted information regarding the color stability of flowable composite materials. The aim of this study was to evaluate the spectrophotometric color stability of three different flowable composite materials with respect to three different pH of saliva. The study included 90 different samples. Thirty samples in each composite group; (Group A: G-aenial universal flo; Group B: Z 350 XT flowable; Group C: Esthet x flow). All samples from each group were immersed in distilled water for 24 hours. Total color difference (ΔE) was recorded for each sample. After this 10 samples from each group were respectively immersed in 6.5, 7 and 7.5 pH of artificial saliva. All samples were kept in dark room for seven days and then ΔE for each sample was recorded and was compared to previous recorded ΔE for the same sample. Maximum color change was seen irrespective of material in 6.5 pH of saliva. G-aenial universal flo showed least change irrespective of pH of saliva. Thus, the present study reveals that acidic pH level affects the coloration of composite resins by affecting the surface integrity and as reported in previous studies, various coloring agents in beverages and other dietary components assists the process due to absorption of these coloring substances into the resin matrix.

The Effect of Energy Densities on the Shear Bond Strength of Self-Adhering Flowable Composite to Er:YAG Pretreated Dentin.

PubMed

Nahas, Paul; Zeinoun, Toni; Majzoub, Zeina; Corbani, Karim; Nammour, Samir

2016-01-01

Objective . To investigate the shear bond strength of self-adhering flowable resin composite, to dentin, after exposing it to Er:YAG laser radiation, at different energy densities. Materials and Methods . Sixty freshly extracted human third molars were randomly divided into five groups ( n = 12). In the control group, dentin was left unirradiated, whereas, in the other four groups, dentin was irradiated with Er:YAG laser in noncontact mode (MSP mode = 100  µ s; 10 Hz; beam diameter: 1.3 mm; speed of 1 mm/second; air 6 mL/min; and water 4 mL/min), and respectively, with the following level of energy (50 mJ, 60 mJ, 80 mJ, and 100 mJ). Then, self-adhering flowable resin composite was bonded to all prepared dentin surfaces. Shear bond strength (SBS) was applied and fractured surfaces were examined using scanning electron microscopy. Results . SBS values showed significant differences in 60 mJ ( P < 0.05) compared to other groups. Morphological evaluation revealed tags or plugs in dentinal tubules, especially when 60 mJ and 80 mJ were used. All four groups tended to leave more residues on the dentin surface, than the control group. Conclusion . Er:YAG dentin irradiation may enhance SBS of the self-adhering flowable resin composite when it is used at the appropriate low level of energy density.

Depth of cure of bulk-fill flowable composite resins.

PubMed

Pedalino, Inaam; Hartup, Grant R; Vandewalle, Kraig S

2015-01-01

In recent years, manufacturers have introduced flowable composite resins that reportedly can be placed in increments of 4 mm or greater. The purpose of this study was to evaluate the depth of cure of bulk-fill flowable composite resins (SureFil SDR Flow, Grandio Flow, and Venus Bulk Fill) and a conventional flowable composite resin (Revolution Formula 2). Depth of cure was measured in terms of bottom-maximum Knoop hardness number (KHN) ratios and the International Organization for Standardization (ISO) 4049 scrape technique. Shades A2 and A3 of SureFil SDR Flow, Grandio Flow, and Revolution Formula 2 were tested. Venus Bulk Fill was tested in its only available shade (universal). Specimens in thicknesses of 2, 3, 4, 5, and 6 mm were polymerized for 20 or 40 seconds, and a hardness tester was used to determine the hardness ratios for each shade at each thickness. For the scraping technique, after specimens were exposed to the curing light, unpolymerized composite resin was removed with a plastic instrument, the polymerized composite was measured, and the length was divided by 2 per ISO guidelines. According to the KHN ratios and the scrape test, Venus Bulk Fill predictably exceeded the manufacturer's claim of a 4-mm depth of cure at both 20 and 40 seconds of curing time. The overall results for depth of cure showed that Venus Bulk Fill ≥ SureFil SDR Flow ≥ Grandio Flow ≥ Revolution Formula 2.

Comparison of the wear and flexural characteristics of flowable resin composites for posterior lesions.

PubMed

Sumino, Natsu; Tsubota, Keishi; Takamizawa, Toshiki; Shiratsuchi, Koji; Miyazaki, Masashi; Latta, Mark A

2013-01-01

To determine the localized wear and flexural properties of flowable resin composites for posterior lesions compared with universal resin composites produced by the same manufacturers. Ten specimens of each of three flowable resins, G-ænial Universal Flo, G-ænial Flo and Clearfil Majesty Flow, and the corresponding resin composite materials, Kalore and Clearfil Majesty Esthetics, were prepared in custom fixtures and subjected to 400,000 wear machine cycles to simulate localized wear. The total maximum depth and volume loss of the wear facets was calculated for each specimen using a profilometer. A three-point bending test was performed to determine the flexural strength, modulus of elasticity and resilience. Values were statistically compared using one-way analysis of variance (ANOVA) followed by Tukey's Honestly Significant Difference (HSD) test. The wear depth ranged from 58.3-126.9 m and the volumetric loss ranged from 0.019-0.049 mm(3), with significant differences observed between restorative materials. The wear depth of G-ænial Universal Flo was significantly smaller than those of the other resin composites tested. The flexural strengths and elastic modulus ranged from 90.5-135.1 MPa and from 4.7-7.6 GPa, respectively. A significantly greater flexural strength and higher elastic modulus was found for G-ænial Universal Flo than the other composites. The wear and mechanical properties of the flowable resin composites tested suggested improved performance compared with universal resin composites.

The Effect of Energy Densities on the Shear Bond Strength of Self-Adhering Flowable Composite to Er:YAG Pretreated Dentin

PubMed Central

Corbani, Karim

2016-01-01

Objective. To investigate the shear bond strength of self-adhering flowable resin composite, to dentin, after exposing it to Er:YAG laser radiation, at different energy densities. Materials and Methods. Sixty freshly extracted human third molars were randomly divided into five groups (n = 12). In the control group, dentin was left unirradiated, whereas, in the other four groups, dentin was irradiated with Er:YAG laser in noncontact mode (MSP mode = 100 µs; 10 Hz; beam diameter: 1.3 mm; speed of 1 mm/second; air 6 mL/min; and water 4 mL/min), and respectively, with the following level of energy (50 mJ, 60 mJ, 80 mJ, and 100 mJ). Then, self-adhering flowable resin composite was bonded to all prepared dentin surfaces. Shear bond strength (SBS) was applied and fractured surfaces were examined using scanning electron microscopy. Results. SBS values showed significant differences in 60 mJ (P < 0.05) compared to other groups. Morphological evaluation revealed tags or plugs in dentinal tubules, especially when 60 mJ and 80 mJ were used. All four groups tended to leave more residues on the dentin surface, than the control group. Conclusion. Er:YAG dentin irradiation may enhance SBS of the self-adhering flowable resin composite when it is used at the appropriate low level of energy density. PMID:27830151

Effect of flowable composite liner and glass ionomer liner on class II gingival marginal adaptation of direct composite restorations with different bonding strategies.

PubMed

Aggarwal, Vivek; Singla, Mamta; Yadav, Suman; Yadav, Harish

2014-05-01

The purpose of the present study was to comparatively evaluate the effect of flowable composite resin liner and resin modified glass ionomer liner on gingival marginal adaptation of class II cavities restored using three bonding agents (Single Bond 3M ESPE, One Coat Self Etching Bond Coltene Whaledent; Adper Easy Bond Self-Etch Adhesive 3M ESPE) and respective composite resins, under cyclic loading. The marginal adaptation was evaluated in terms of 'continuous margin' (CM) at the gingival margin. Ninety class II cavities with margins extending 1mm below the cement-enamel junction were prepared in extracted mandibular third molars. The samples were divided into three groups: no liner placement; 0.5-1mm thick flowable resin liner placement (Filtek Z350 XT flowable resin) on gingival floor and; light cure glass ionomer (Ketac N100) liner. The groups were further subdivided into three sub-groups on the basis of the bonding agents used. Cavities were restored with composite resins (Z350 for Single Bond and Adper Easy Bond; and Synergy D6 Universal, for One Coat Self Etching Bond) in 2mm increments and the samples were mechanically loaded (60N, 1,50,000 cycles). Marginal adaptation was evaluated using a low vacuum scanning electron microscope. Statistical analysis was done with two way ANOVA with Holm-Sidak's correction for multiple comparisons. Placement of flowable composite liner significantly improved the CM values of Single Bond (78±11%) and One Coat Self Etching Bond (77±9%) compared with no liner group, but the values of CM of Adper Easy Bond were not improved (61±12%). Placement of glass ionomer liner significantly improved the values of CM in all the sub-groups (78±9%, 72±10% and 77±10% for Single Bond, One Coat Self Etching Bond & Adper Easy Bond respectively) compared with no liner group. Placement of liners improved the values of 'continuous margin' in the gingival floor of the proximal cavities restored with composite resins using different bonding agent. Placement of flowable composite liner or glass ionomer liner will improve the marginal integrity of composite restorations using etch-and-rinse and two bottle-two step self etch adhesives. To improve the marginal integrity of a single bottle adhesive, glass ionomer liner should be applied. Copyright © 2014 Elsevier Ltd. All rights reserved.

Demonstration and Validation of Controlled Low-Strength Materials for Corrosion Mitigation of Buried Steel Pipes: Final Report on Project F09-A17

DTIC Science & Technology

2015-12-01

steel surfaces. Two different CLSM blends were tested. Both used cement and a flowability admixture, but one used native soil instead of standard...by about 63% in the soil cement . Therefore, CLSMs can reduce the cost of applying CP to buried steel structures. The return-on-investment ratio for...was exposed in the native-soil backfill to deter- mine the corrosion rate in the absence of any flowable fill or soil cement . The removable steel

Repair of bis-acryl provisional restorations using flowable composite resin.

PubMed

Bohnenkamp, David M; Garcia, Lily T

2004-11-01

Provisional restorations provide interim coverage for prepared teeth while fixed definitive restorations are fabricated. Several types of autopolymerizing acrylic resins have been used for many years to fabricate provisional restorations. In recent years, bis-acryl resin composite material has gained popularity among clinicians for the direct fabrication of provisional fixed restorations. Occasionally, deficiencies may occur while fabricating a direct provisional restoration and require chairside repair. This article describes an effective procedure for the use of light-polymerized flowable composite resin for the intraoral repair of bis-acryl provisional restorations.

The Electrochemical Flow Capacitor: Capacitive Energy Storage in Flowable Media

NASA Astrophysics Data System (ADS)

Dennison, Christopher R.

Electrical energy storage (EES) has emerged as a necessary aspect of grid infrastructure to address the increasing problem of grid instability imposed by the large scale implementation of renewable energy sources (such as wind or solar) on the grid. Rapid energy recovery and storage is critically important to enable immediate and continuous utilization of these resources, and provides other benefits to grid operators and consumers as well. In past decades, there has been significant progress in the development of electrochemical EES technologies which has had an immense impact on the consumer and micro-electronics industries. However, these advances primarily address small-scale storage, and are often not practical at the grid-scale. A new energy storage concept called "the electrochemical flow capacitor (EFC)" has been developed at Drexel which has significant potential to be an attractive technology for grid-scale energy storage. This new concept exploits the characteristics of both supercapacitors and flow batteries, potentially enabling fast response rates with high power density, high efficiency, and long cycle lifetime, while decoupling energy storage from power output (i.e., scalable energy storage capacity). The unique aspect of this concept is the use of flowable carbon-electrolyte slurry ("flowable electrode") as the active material for capacitive energy storage. This dissertation work seeks to lay the scientific groundwork necessary to develop this new concept into a practical technology, and to test the overarching hypothesis that energy can be capacitively stored and recovered from a flowable media. In line with these goals, the objectives of this Ph.D. work are to: i) perform an exploratory investigation of the operating principles and demonstrate the technical viability of this new concept and ii) establish a scientific framework to assess the key linkages between slurry composition, flow cell design, operating conditions and system performance. To achieve these goals, a combined experimental and computational approach is undertaken. The technical viability of the technology is demonstrated, and in-depth studies are performed to understand the coupling between flow rate and slurry conductivity, and localized effects arising within the cell. The outlook of EFCs and other flowable electrode technologies is assessed, and opportunities for future work are discussed.

Comparative Study of the Shear Bond Strength of Flowable Composite in Permanent Teeth Treated with Conventional Bur and Contact or Non-Contact Er:YAG Laser

PubMed Central

Parhami, Parisa; Pourhashemi, Seyed Jalal; Ghandehari, Mehdi; Mighani, Ghasem; Chiniforush, Nasim

2014-01-01

Introduction: The aim of this study was to evaluate and compare the in vitro effect of the Erbium-Doped Yttrium Aluminum Garnet (Er:YAG) laser with different radiation distances and high-speed rotary treatment on the shear bond strength of flowable composite to enamel of human permanent posterior teeth. Methods: freshly extracted human molar teeth with no caries or other surface defects were used in this study (n=45). The teeth were randomly divided into 3 groups. Group 1: treated with non-contact Er:YAG Laser and etched with Er:YAG laser, Group 2: treated with contact Er:YAG Laser and etched with Er:YAG laser, Group 3 (control): treated with diamond fissure bur and etched with acid phosphoric 37%. Then the adhesive was applied on the surafces of the teeth and polymerized using a curing light appliance. Resin cylinders were fabricated from flowable composite. Shear bond strength was tested at a crosshead speed of 0.5 mm/min. Results: The amount of Shear Bond Strength (SBS) in the 3 treatment groups was not the same (P<0.05).The group in which enamel surfaces were treated with diamond fissure bur and etched with acid (conrtol group) had the highest mean shear bond strength (19.92±4.76) and the group in which the enamel surfaces were treated with contact Er:YAG laser and etched with Er:YAG laser had the lowest mean shear bond strength (10.89±2.89). Mann-whitney test with adjusted P-value detected significant difference in shear bond strength between the control group and the other 2 groups (P < 0.05). Conclusion: It was concluded that both contact and non-contact Er:YAG laser treatment reduced shear bond strength of flowable resin composite to enamel in comparison with conventional treatment with high speed rotary. Different Er:YAG laser distance irradiations did not influence the shear bond strength of flowable composite to enamel. PMID:25653813

A novel process for production of spherical PBT powders and their processing behavior during laser beam melting

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

Schmidt, Jochen, E-mail: jochen.schmidt@fau.de; Sachs, Marius; Fanselow, Stephanie

2016-03-09

Additive manufacturing processes like laser beam melting of polymers are established for production of prototypes and individualized parts. The transfer to other areas of application and to serial production is currently hindered by the limited availability of polymer powders with good processability. Within this contribution a novel process route for the production of spherical polymer micron-sized particles of good flowability has been established and applied to produce polybutylene terephthalate (PBT) powders. Moreover, the applicability of the PBT powders in selective laser beam melting and the dependencies of process parameters on device properties will be outlined. First, polymer micro particles aremore » produced by a novel wet grinding method. To improve the flowability the produced particles the particle shape is optimized by rounding in a heated downer reactor. A further improvement of flowability of the cohesive spherical PBT particles is realized by dry coating. An improvement of flowability by a factor of about 5 is achieved by subsequent rounding of the comminution product and dry-coating as proven by tensile strength measurements of the powders. The produced PBT powders were characterized with respect to their processability. Therefore thermal, rheological, optical and bulk properties were analyzed. Based on these investigations a range of processing parameters was derived. Parameter studies on thin layers, produced in a selective laser melting system, were conducted. Hence appropriate parameters for processing the PBT powders by laser beam melting, like building chamber temperature, scan speed and laser power have been identified.« less

Fissure sealant materials: Wear resistance of flowable composite resins.

PubMed

Asefi, Sohrab; Eskandarion, Solmaz; Hamidiaval, Shadi

2016-01-01

Background. Wear resistance of pit and fissure sealant materials can influence their retention. Wear characteristics of sealant materials may determine scheduling of check-up visits. The aim of this study was to compare wear resistance of two flowable composite resins with that of posterior composite resin materials. Methods. Thirty-five disk-shaped specimens were prepared in 5 groups, including two flowable composite resins (Estelite Flow Quick and Estelite Flow Quick High Flow), Filtek P90 and Filtek P60 and Tetric N-Ceram. The disk-shaped samples were prepared in 25-mm diameter by packing them into a two-piece aluminum mold and then light-cured. All the specimens were polished for 1minute using 600-grit sand paper. The samples were stored in distilled water at room temperature for 1 week and then worn by two-body abrasion test using "pin-on-disk" method (with distilled water under a 15-Nload at 0.05 m/s, for a distance of 100 meter with Steatite ceramic balls antagonists). A Profilometer was used for evaluating the surface wear. Data were analyzed with the one-way ANOVA. Results. Estelite Flow Quick exhibited 2708.9 ± 578.1 μm(2) and Estelite Flow Quick High Flow exhibited 3206 ± 2445.1 μm(2)of wear but there were no significant differences between the groups. They demonstrated similar wear properties. Conclusion. Estelite flowable composite resins have wear resistance similar to nano- and micro-filled and micro-hybrid composite resins. Therefore, they can be recommended as pit and fissure sealant materials in the posterior region with appropriate mechanical characteristics.

Fissure sealant materials: Wear resistance of flowable composite resins

PubMed Central

Asefi, Sohrab; Eskandarion, Solmaz; Hamidiaval, Shadi

2016-01-01

Background. Wear resistance of pit and fissure sealant materials can influence their retention. Wear characteristics of sealant materials may determine scheduling of check-up visits. The aim of this study was to compare wear resistance of two flowable composite resins with that of posterior composite resin materials. Methods. Thirty-five disk-shaped specimens were prepared in 5 groups, including two flowable composite resins (Estelite Flow Quick and Estelite Flow Quick High Flow), Filtek P90 and Filtek P60 and Tetric N-Ceram. The disk-shaped samples were prepared in 25-mm diameter by packing them into a two-piece aluminum mold and then light-cured. All the specimens were polished for 1minute using 600-grit sand paper. The samples were stored in distilled water at room temperature for 1 week and then worn by two-body abrasion test using "pin-on-disk" method (with distilled water under a 15-Nload at 0.05 m/s, for a distance of 100 meter with Steatite ceramic balls antagonists). A Profilometer was used for evaluating the surface wear. Data were analyzed with the one-way ANOVA. Results. Estelite Flow Quick exhibited 2708.9 ± 578.1 μm2 and Estelite Flow Quick High Flow exhibited 3206 ± 2445.1 μm2of wear but there were no significant differences between the groups. They demonstrated similar wear properties. Conclusion. Estelite flowable composite resins have wear resistance similar to nano- and micro-filled and micro-hybrid composite resins. Therefore, they can be recommended as pit and fissure sealant materials in the posterior region with appropriate mechanical characteristics. PMID:27651887

[Effect of concomitant use of dental drug on the properties of recombinant human basic fibroblast growth factor formulation for periodontal disease].

PubMed

Sato, Yasuhiko; Oba, Takuma; Danjo, Kazumi

2013-01-01

We have discussed the essential property for periodontal disease medication using protein, such as recombinant human basic fibroblast growth factor (rhbFGF). In our previous study, the criteria of thickener for the medication, viscosity, flowability etc., were set. The aim of this study was to evaluate the physical and chemical effect of concomitant use of general dental drug or device on thickener properties for the clinical use of viscous rhbFGF formulation. Viscous formulation was prepared with six cellulose derivatives, two types hydroxy propyl cellulose (HPC), three types hydroxy ethyl cellulose (HEC) and methyl cellulose (MC). Antibiotic ointment, local anesthetic, bone graft substitute, agent for gargle and mouthwashes, were chosen as general dental drug and device. These drugs and device were mixed with the viscous formulations and the change of viscosity and flowability, the remaining ratio of rhbFGF were evaluated. When the various thickener solutions were mixed with the liquid drugs, viscosity and flowability did not changed much. However, in the case of MC solution, viscous property declined greatly when MC solution was mixed with cationic surfactant for gargle. The flowabilities of thickener solutions were declined with insoluble bone graft. The stabilities of rhbFGF in thickener solutions were no problem for 24 hours even in the case of mixing with dental drug or device. Our findings suggested that the viscous rhbFGF formulations prepared in this research were not substantially affected by the concomitant use of dental drug or device, especially the formulation with HPC or HEC was useful.

Shear bond strength of a new self-adhering flowable composite resin for lithium disilicate-reinforced CAD/CAM ceramic material

PubMed Central

Sancakli, Hande Sar; Sancakli, Erkan; Eren, Meltem Mert; Ozel, Sevda; Yucel, Taner; Yildiz, Esra

2014-01-01

PURPOSE The purpose of this study was to evaluate and compare the effects of different surface pretreatment techniques on the surface roughness and shear bond strength of a new self-adhering flowable composite resin for use with lithium disilicate-reinforced CAD/CAM ceramic material. MATERIALS AND METHODS A total of one hundred thirty lithium disilicate CAD/CAM ceramic plates with dimensions of 6 mm × 4 mm and 3 mm thick were prepared. Specimens were then assigned into five groups (n=26) as follows: untreated control, coating with 30 µm silica oxide particles (Cojet™ Sand), 9.6% hydrofluoric acid etching, Er:YAG laser irradiation, and grinding with a high-speed fine diamond bur. A self-adhering flowable composite resin (Vertise Flow) was applied onto the pre-treated ceramic plates using the Ultradent shear bond Teflon mold system. Surface roughness was measured by atomic force microscopy. Shear bond strength test were performed using a universal testing machine at a crosshead speed of 1 mm/min. Surface roughness data were analyzed by one-way ANOVA and the Tukey HSD tests. Shear bond strength test values were analyzed by Kruskal-Wallis and Mann-Whitney U tests at α=.05. RESULTS Hydrofluoric acid etching and grinding with high-speed fine diamond bur produced significantly higher surface roughness than the other pretreatment groups (P<.05). Hydrofluoric acid etching and silica coating yielded the highest shear bond strength values (P<.001). CONCLUSION Self-adhering flowable composite resin used as repair composite resin exhibited very low bond strength irrespective of the surface pretreatments used. PMID:25551002

DEVELOPMENT AND DEMONSTRATION OF A PILOT SCALE FACILITY FOR FABRICATION AND MARKETING OF LIGHTWEIGHT-COAL COMBUSTION BYPRODUCTS-BASED SUPPORTS AND MINE VENTILATION BLOCKS FOR UNDERGROUND MINES

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

Yoginder P. Chugh

2002-10-01

The overall goal of this program was to develop a pilot scale facility, and design, fabricate, and market CCBs-based lightweight blocks for mine ventilation control devices, and engineered crib elements and posts for use as artificial supports in underground mines to replace similar wooden elements. This specific project was undertaken to (1) design a pilot scale facility to develop and demonstrate commercial production techniques, and (2) provide technical and marketing support to Fly Lite, Inc to operate the pilot scale facility. Fly Lite, Inc is a joint venture company of the three industrial cooperators who were involved in research intomore » the development of CCBs-based structural materials. The Fly-Lite pilot scale facility is located in McLeansboro, Illinois. Lightweight blocks for use in ventilation stoppings in underground mines have been successfully produced and marketed by the pilot-scale facility. To date, over 16,000 lightweight blocks (30-40 pcf) have been sold to the mining industry. Additionally, a smaller width (6-inch) full-density block was developed in August-September 2002 at the request of a mining company. An application has been submitted to Mine Safety and Health Administration for the developed block approval for use in mines. Commercialization of cribs and posts has also been accomplished. Two generations of cribs have been developed and demonstrated in the field. MSHA designated them suitable for use in mines. To date, over 2,000 crib elements have been sold to mines in Illinois. Two generations of posts were also demonstrated in the field and designated as suitable for use in mines by MSHA. Negotiations are currently underway with a mine in Illinois to market about 1,000 posts per year based on a field demonstration in their mine. It is estimated that 4-5 million tons CCBs (F-fly ash or FBC fly ash) may be utilized if the developed products can be commercially implemented in U.S. coal and non-coal mines.« less

Physical Properties of an Ag-Doped Bioactive Flowable Composite Resin

PubMed Central

Kattan, Hiba; Chatzistavrou, Xanthippi; Boynton, James; Dennison, Joseph; Yaman, Peter; Papagerakis, Petros

2015-01-01

The aim of this work was to study the physical and antibacterial properties of a flowable resin composite incorporating a sol-gel derived silver doped bioactive glass (Ag-BGCOMP). The depth of the cure was calculated by measuring the surface micro-hardness for the top and bottom surfaces. The volumetric polymerization shrinkage was measured by recording the linear shrinkage as change in length, while the biaxial flexural strength was studied measuring the load at failure. The antibacterial properties of the samples were tested against Streptococcus mutans (S. mutans) and Lactobacillus casei (L. casei). The measured values were slightly decreased for all tested physical properties compared to those of control group (flowable resin composite without Ag-BG), however enhanced bacteria inhibition was observed for Ag-BGCOMP. Ag-BGCOMP could find an application in low stress-bearing areas as well as in small cavity preparations to decrease secondary caries. This work provides a good foundation for future studies on evaluating the effects of Ag-BG addition into packable composites for applications in larger cavity preparations where enhanced mechanical properties are needed. PMID:28793463

Physico-mechanical and thermal characteristics of commercially available and newly developed dental flowable composites

NASA Astrophysics Data System (ADS)

Kamalak, Hakan; Canbay, C. Aksu; Yiğit, Oktay; Altin, Serdar

2018-03-01

In this study, we investigated the structural stability, thermal conductivity, thermal analysis, materials' homogeneity of newly developed flowable composites. 6 different dental flowable composite resins; Grandio Flow (GF), Charisma Flow (CF), Tetric N Flow (TNF), Clearfil Majesty Flow (CMF),3M Filtek Ultimate Flow (3MFU), Voco Amaris Flow (VFA) were used. Restorations were made in standard teflon molds and the materials were light-cured for 20s in a 6 mm × 2 mm teflon mould. After polymerization, samples were kept in distilled water at 37 °C/24 h .It was found that the composites have multiphase component such as metallic dopant and organic binder. The XRD investigation showed that there was a broad halo in the pattern which indicates the organic section in the composites. The FTIR results indicate the bond structure of the composites. The temperature dependence of the thermal conductivity of the composites were found below to 5 mW/K value depending on the type of the composites, which are low enough for dental application. The micro-hardness of the samples was analyzed and the result was compared.

Controversies in clinicopathological characteristics and treatment strategies of male breast cancer: A review of the literature.

PubMed

Losurdo, Agnese; Rota, Selene; Gullo, Giuseppe; Masci, Giovanna; Torrisi, Rosalba; Bottai, Giulia; Zuradelli, Monica; Gatzemeier, Wolfgang; Santoro, Armando

2017-05-01

Male breast cancer (MaBC) is a rare disease, accounting for less than 1% of malignancies in men. For this reason, literature data on its clinicopathological characteristics are very heterogeneous and treatment strategies have mostly been extrapolated from the female counterpart. However, immunohistochemical peculiarities of MaBC have recently emerged, defining it as a distinct entity from female breast cancer (FBC), thus requiring a tailored clinical approach. MaBC appears to be more often hormone receptor positive than FBC, while data on HER2 status still remain inconclusive, indicating a possible higher incidence of HER2 alterations. Treatment strategies for MaBC have evolved and less invasive local treatments such as lumpectomy and sentinel lymph node biopsy have become part of everyday clinical practice, while there are still controversies on the indication of radiotherapy, especially after mastectomy. Similarly, differences between male and female hormonal status have raised some concerns in the use of aromatase inhibitors in male patients and the choice of best endocrine therapy is still controversial. Copyright © 2017 Elsevier B.V. All rights reserved.

Competitive sorption affinity of sulfonamides and chloramphenicol antibiotics toward functionalized biochar for water and wastewater treatment.

PubMed

Ahmed, Mohammad Boshir; Zhou, John L; Ngo, Huu Hao; Guo, Wenshan; Johir, Md Abu Hasan; Belhaj, Dalel

2017-08-01

Competitive sorption of sulfamethazine (SMT), sulfamethoxazole (SMX), sulfathiazole (STZ) and chloramphenicol (CP) toward functionalized biochar (fBC) was highly pH dependent with maximum sorption at pH ∼4.0-4.25. Equilibrium data were well represented by the Langmuir and Freundlich models in the order STZ>SMX>CP>SMT. Kinetics data were slightly better fitted by the pseudo second-order model than pseudo first-order and intra-particle-diffusion models. Maximum sorptive interactions occurred at pH 4.0-4.25 through H-bonds formations for neutral sulfonamides species and through negative charge assisted H-bond (CAHB) formation for CP, in addition to π-π electron-donor-acceptor (EDA) interactions. EDA was the main mechanism for the sorption of positive sulfonamides species and CP at pH<2.0. Sorption of negative sulfonamides species and CP at pH>7.0 was regulated by H-bond formation and proton exchange with water by forming CAHB, respectively. The results suggested fBC to be highly efficient in removing antibiotics mixture. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evaluation of Four Different Restorative Materials for Restoration of the Periodontal Condition of Wedge-Shaped Defect: A Comparative Study.

PubMed

Ruan, Jian-Yong; Gong, Zheng-Lin; Zhang, Rui-Zhi; Zhang, Zhe; Xu, Ran; Li, Da-Xu; Ren, Le; Tao, Hong

2017-09-16

BACKGROUND This study aimed to conduct a clinical evaluation of four restorative materials for restoration of dental wedge-shaped defect (WSD) and their impacts on periodontal tissues. MATERIAL AND METHODS A total of 280 maxillary premolars with dental WSD were selected from 106 patients; the patient cases were divided into eight groups according to different combinations of restorative materials (flowable resin composites, Dyract compomers, glass ionomer cement (GIC), light-curing composite resin), and WSD positions (approaching gingival and subgingival positions). Gingival crevicular fluid (GCF) volume, levels of aspartate aminotransferase (AST), alkaline phosphatase (ALP), and interleukin-1β (IL-1β) in GCF were analyzed, while probing depth (PD), plaque index (PLI), and sulcus bleeding index (SBI) were also measured. The periodontal conditions of all patients were followed prior to restoration, as well as six months and 12 months after restoration. RESULTS After six months of restoration, the overall clinical success rates of flowable resin composites, Dyract compomers, and light-curing composite resin were greater than those of GIC. GCF volume, GCF-AST, IL-1β levels, PD, PLI, and SBI of cases restored by GIC were higher than those restored by the other three materials. After 12 months of restoration, the overall clinical success rates of flowable resin composites and Dyract compomers were greater than those of light-curing composite resin and GIC. GCF volume, GCF-AST, GCF-ALP, IL-1β levels, PD, PLI, and SBI of cases restored by GIC were higher than those restored by the other three materials. CONCLUSIONS Our study provided evidence that the clinical efficacy of flowable resin composites, Dyract compomers, and light-curing composite resin was greater than that of GIC for restoration of dental WSD.

Evaluation of Four Different Restorative Materials for Restoration of the Periodontal Condition of Wedge-Shaped Defect: A Comparative Study

PubMed Central

Ruan, Jian-Yong; Gong, Zheng-Lin; Zhang, Rui-Zhi; Zhang, Zhe; Xu, Ran; Li, Da-Xu; Ren, Le; Tao, Hong

2017-01-01

Background This study aimed to conduct a clinical evaluation of four restorative materials for restoration of dental wedge-shaped defect (WSD) and their impacts on periodontal tissues. Material/Methods A total of 280 maxillary premolars with dental WSD were selected from 106 patients; the patient cases were divided into eight groups according to different combinations of restorative materials (flowable resin composites, Dyract compomers, glass ionomer cement (GIC), light-curing composite resin), and WSD positions (approaching gingival and subgingival positions). Gingival crevicular fluid (GCF) volume, levels of aspartate aminotransferase (AST), alkaline phosphatase (ALP), and interleukin-1β (IL-1β) in GCF were analyzed, while probing depth (PD), plaque index (PLI), and sulcus bleeding index (SBI) were also measured. The periodontal conditions of all patients were followed prior to restoration, as well as six months and 12 months after restoration. Results After six months of restoration, the overall clinical success rates of flowable resin composites, Dyract compomers, and light-curing composite resin were greater than those of GIC. GCF volume, GCF-AST, IL-1β levels, PD, PLI, and SBI of cases restored by GIC were higher than those restored by the other three materials. After 12 months of restoration, the overall clinical success rates of flowable resin composites and Dyract compomers were greater than those of light-curing composite resin and GIC. GCF volume, GCF-AST, GCF-ALP, IL-1β levels, PD, PLI, and SBI of cases restored by GIC were higher than those restored by the other three materials. Conclusions Our study provided evidence that the clinical efficacy of flowable resin composites, Dyract compomers, and light-curing composite resin was greater than that of GIC for restoration of dental WSD. PMID:28917087

Characterization of bulk and shear properties of basmati and non-basmati rice flour.

PubMed

Jan, Shumaila; Ghoroi, Chinmay; Saxena, Dharmesh Chandra

2018-01-01

Flours are often unstable in relation to their flow performance, which is evident when a free-flowing material ceases to flow and the processing, handling, and production parameters depend on the inherent powder characteristics and their bulk behaviour. The present study was conducted to compare the flowability of basmati and non-basmati rice flour affecting bulk handling, which could be related to its particle size, shape and surface roughness (measured by atomic force microscopy) as well as bulk and shear properties, depending upon the processing conditions. Particle size (171.1-171.9 μm) of both samples was not significantly different. However, the flowability of the non-basmati rice flour was significantly affected by its particle shape (circularity 0.487), surface roughness (124.23 nm) and compressibility (25.32%) in comparison to basmati rice flour (circularity 0.653, surface roughness 113.59 nm and compressibility 21.09%), making it more cohesive than basmati rice flour. Also, basic flow energy was significantly higher in non-basmati flour, thus requiring more energy (147.54 mJ) to flow than basmati rice flour (130.15 mJ). Overall, flowability was analysed by applying three different pressures (3, 6 and 9 kPa), among which non-basmati rice flour was found to be less flowable (flow function coefficient (FFC) 2.33 at 9 kPa) in comparison to basmati (FFC 3.35 at 9 kPa), making bulk handling difficult. This study could be useful in designing processing equipment, hoppers and silos for rice flour handling. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Does the use of a novel self-adhesive flowable composite reduce nanoleakage?

PubMed

Naga, Abeer Abo El; Yousef, Mohammed; Ramadan, Rasha; Fayez Bahgat, Sherif; Alshawwa, Lana

2015-01-01

The aim of the study reported here was to evaluate the performance of a self-adhesive flowable composite and two self-etching adhesive systems, when subjected to cyclic loading, in preventing the nanoleakage of Class V restorations. Wedge-shape Class V cavities were prepared (4×2×2 mm [length × width × depth]) on the buccal surfaces of 90 sound human premolars. Cavities were divided randomly into three groups (n=30) according to the used adhesive (Xeno(®) V [self-etching adhesive system]) and BOND-1(®) SF (solvent-free self-etching adhesive system) in conjunction with Artiste(®) Nano Composite resin, and Fusio™ Liquid Dentin (self-adhesive flowable composite), consecutively. Each group was further divided into three subgroups (n=10): (A) control, (B) subjected to occlusal cyclic loading (90N for 5,000 cycles), and (C) subjected to occlusal cyclic loading (90N for 10,000 cycles). Teeth then were coated with nail polish up to 1 mm from the interface, immersed in 50% silver nitrate solution for 24 hours and tested for nanoleakage using the environmental scanning electron microscopy and energy dispersive analysis X-ray analysis. Data were statistically analyzed using two-way analysis of variance and Tukey's post hoc tests (P≤0.05). The Fusio Liquid Dentin group showed statistically significant lower percentages of silver penetration (0.55 μ) compared with the BOND-1 SF (3.45 μ) and Xeno V (3.82 μ) groups, which were not statistically different from each other, as they both showed higher silver penetration. Under the test conditions, the self-adhesive flowable composite provided better sealing ability. Aging of the two tested adhesive systems, as a function of cyclic loading, increased nanoleakage.

Does the use of a novel self-adhesive flowable composite reduce nanoleakage?

PubMed Central

Naga, Abeer Abo El; Yousef, Mohammed; Ramadan, Rasha; Fayez Bahgat, Sherif; Alshawwa, Lana

2015-01-01

Objective The aim of the study reported here was to evaluate the performance of a self-adhesive flowable composite and two self-etching adhesive systems, when subjected to cyclic loading, in preventing the nanoleakage of Class V restorations. Methods Wedge-shape Class V cavities were prepared (4×2×2 mm [length × width × depth]) on the buccal surfaces of 90 sound human premolars. Cavities were divided randomly into three groups (n=30) according to the used adhesive (Xeno® V [self-etching adhesive system]) and BOND-1® SF (solvent-free self-etching adhesive system) in conjunction with Artiste® Nano Composite resin, and Fusio™ Liquid Dentin (self-adhesive flowable composite), consecutively. Each group was further divided into three subgroups (n=10): (A) control, (B) subjected to occlusal cyclic loading (90N for 5,000 cycles), and (C) subjected to occlusal cyclic loading (90N for 10,000 cycles). Teeth then were coated with nail polish up to 1 mm from the interface, immersed in 50% silver nitrate solution for 24 hours and tested for nanoleakage using the environmental scanning electron microscopy and energy dispersive analysis X-ray analysis. Data were statistically analyzed using two-way analysis of variance and Tukey’s post hoc tests (P≤0.05). Results The Fusio Liquid Dentin group showed statistically significant lower percentages of silver penetration (0.55 μ) compared with the BOND-1 SF (3.45 μ) and Xeno V (3.82 μ) groups, which were not statistically different from each other, as they both showed higher silver penetration. Conclusion Under the test conditions, the self-adhesive flowable composite provided better sealing ability. Aging of the two tested adhesive systems, as a function of cyclic loading, increased nanoleakage. PMID:25848318

Investigation of Self Consolidating Concrete Containing High Volume of Supplementary Cementitious Materials and Recycled Asphalt Pavement Aggregates

NASA Astrophysics Data System (ADS)

Patibandla, Varun chowdary

The use of sustainable technologies such as supplementary cementitiuous materials (SCMs), and/or recycled materials is expected to positively affect the performance of concrete mixtures. However, it is important to study and qualify such mixtures and check if the required specifications of their intended application are met before they can be implemented in practice. This study presents the results of a laboratory investigation of Self Consolidating concrete (SCC) containing sustainable technologies. A total of twelve concrete mixtures were prepared with various combinations of fly ash, slag, and recycled asphalt pavement (RAP). The mixtures were divided into three groups with constant water to cementitiuous materials ratio of 0.37, and based on the RAP content; 0, 25, and 50% of coarse aggregate replaced by RAP. All mixtures were prepared to achieve a target slump flow equal to or higher than 500 mm (24in). A control mixture for each group was prepared with 100% Portland cement whereas all other mixtures were designed to have up to 70% of portland cement replaced by a combination of supplementary cementitiuous materials (SCMs) such as class C fly ash and granulated blast furnace slag. The properties of fresh concrete investigated in this study include flowability, deformability; filling capacity, and resistance to segregation. In addition, the compressive strength at 3, 14, and 28 days, the tensile strength, and the unrestrained shrinkage up to 80 days was also investigated. As expected the inclusion of the sustainable technologies affected both fresh and hardened concrete properties. Analysis of the experimental data indicated that inclusion of RAP not only reduces the ultimate strength, but it also affected the compressive strength development rate. Moreover, several mixes satisfied compressive strength requirements for pavements and bridges; those mixes included relatively high percentages of SCMs and RAP. Based on the results obtained in this study, it is not recommended to replace the coarse aggregate in SCC by more than 25% RAP.

Linking flowability and granulometry of lactose powders.

PubMed

Boschini, F; Delaval, V; Traina, K; Vandewalle, N; Lumay, G

2015-10-15

The flowing properties of 10 lactose powders commonly used in pharmaceutical industries have been analyzed with three recently improved measurement methods. The first method is based on the heap shape measurement. This straightforward measurement method provides two physical parameters (angle of repose αr and static cohesive index σr) allowing to make a first screening of the powder properties. The second method allows to estimate the rheological properties of a powder by analyzing the powder flow in a rotating drum. This more advanced method gives a large set of physical parameters (flowing angle αf, dynamic cohesive index σf, angle of first avalanche αa and powder aeration %ae) leading to deeper interpretations. The third method is an improvement of the classical bulk and tapped density measurements. In addition to the improvement of the measurement precision, the densification dynamics of the powder bulk submitted to taps is analyzed. The link between the macroscopic physical parameters obtained with these methods and the powder granulometry is analyzed. Moreover, the correlations between the different flowability indexes are discussed. Finally, the link between grain shape and flowability is discussed qualitatively. Copyright © 2015 Elsevier B.V. All rights reserved.

Design and scale-up of a semi-industrial downer-reactor for the rounding of irregular polymer particles

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

Sachs, Marius; Schmidt, Jochen; Peukert, Wolfgang

2016-03-09

The recent development of rapid prototyping technologies towards additive manufacturing reveals some major drawbacks of processes such as laser beam melting (LBM). This contribution focuses on the lack of suitable polymer material with a fine particle size and good flowability. Polymer particles obtained by a wet grinding process 1 are treated in a heated downer reactor. This treatment changes the particles’ morphology from a chiselled state towards a spherical form by surface tension forces in a molten state 2 and leads to an improved flowability. To reach the required amount of rounded polymer powder, a downer reactor in semi-industrial scalemore » has been established and will be characterized in this article. For the purpose of particle rounding it is necessary to avoid contact of molten particles with each other and with the hot reactor walls. Furthermore, the heat distribution has been investigated as one of the key parameters of the process. Finally, a proof of concept by rounding wet grinded PBT material was successfully conducted. The product was examined to obtain data about a change in particle size and flowability.« less

Effects of mild processing pressures on the performance of dry powder inhaler formulations for inhalation therapy. 1: Budesonide and lactose.

PubMed

Marek, Steve R; Donovan, Martin J; Smyth, Hugh D C

2011-05-01

Batch-to-batch variability, whereby distinct batches of dry powder inhaler formulations, though manufactured with identical components and specifications, may exhibit significant variations in aerosol performance, is a major obstacle to consistent and reproducible drug delivery for inhalation therapy. This variability may arise from processing or manufacturing effects that have yet to be investigated. This study focused on the potential effects of mild compression forces experienced during powder manufacture and transport (such as during the filling of, or storage in, a hopper) on the flowability and aerosol performance of a lactose-based dry powder inhaler formulation. Different grades of inhalation lactose were subjected to typical compression forces by either placing a weight of known mass on the sample or by using a Texture Analyzer to apply a constant force while measuring the distance of compaction. Powder flowability was evaluated with a rotating drum apparatus by imaging the avalanching of the powder over time. The average avalanche angle and avalanche time were used to determine the flowability of each sample, both before and after compression treatment. Aerosol performance of treated and untreated lactose/budesonide blends (2% (w/w)) was assessed in dispersion studies using a next generation impactor. At compression forces in excess of 5 kPa, the flowability of milled lactose was decreased relative to the untreated sample. Compression of lactose prior to blending caused a decrease in in vitro aerosol dispersion performance. However, dispersion performance was unchanged when compression occurred subsequent to drug blending. In contrast, inhalation grade sieved lactose, differing from the milled grade with a lower concentration of lactose fines (<10 μm) and larger overall particle sizes, exhibited no statistical differences in either flowability or dispersion performance across all experimental treatments. Thus, the compression of the lactose fines onto the surfaces of the larger lactose particles due to mild processing pressures is hypothesized to be the cause of these observed performance variations. It was shown that simulations of storage and transport in an industrial scale hopper can induce significant variations in formulation performance, and it is speculated that this could be a source of batch-to-batch variations. Copyright © 2011 Elsevier B.V. All rights reserved.

An Evaluation of the Validity and Reliability of a Food Behavior Checklist Modified for Children

ERIC Educational Resources Information Center

Branscum, Paul; Sharma, Manoj; Kaye, Gail; Succop, Paul

2010-01-01

Objective: The objective of this study was to report the construct validity and internal consistency reliability of the Food Behavior Checklist modified for children (FBC-MC), with low-income, Youth Expanded Food and Nutrition Education Program (EFNEP)-eligible children. Methods: Using a cross-sectional research design, construct validity was…

EXPERIMENTAL STUDY OF HIGH LEVELS OF SO2 REMOVAL IN ATMOSPHERIC-PRESSURE FUIDIZED-BED COMBUSTORS

EPA Science Inventory

The report describes tests conducted in an atmospheric-pressure-fluidized-bed combustor (FBC) with a cross-section of 1 x 1.6 m) to demonstrate high levels of S02 removal when burning a high-sulfur coal and feeding limestone sorbent for S02 removal. The goal was to achieve 90-plu...

Inserting new technology into small missions

NASA Technical Reports Server (NTRS)

Deutsch, L. J.

2001-01-01

Part of what makes small missions small is that they have less money. Executing missions at low cost implies extensive use of cost sharing with other missions or use of existing solutions. However, in order to create many small missions, new technology must be developed, applied, and assimilated. Luckily, there are methods for creating new technology and inserting it into faster-better-cheaper (FBC) missions.

Assessing the combined influence of TOC and black carbon in soil-air partitioning of PBDEs and DPs from the Indus River Basin, Pakistan.

PubMed

Ali, Usman; Mahmood, Adeel; Syed, Jabir Hussain; Li, Jun; Zhang, Gan; Katsoyiannis, Athanasios; Jones, Kevin C; Malik, Riffat Naseem

2015-06-01

Levels of polybrominated diphenyl ethers (PBDEs) and dechlorane plus (DPs) were investigated in the Indus River Basin from Pakistan. Concentrations of ∑PBDEs and ∑DPs were ranged between 0.05 and 2.38 and 0.002-0.53 ng g(-1) in the surface soils while 1.43-22.1 and 0.19-7.59 pg m(-3) in the passive air samples, respectively. Black carbon (fBC) and total organic carbon (fTOC) fractions were also measured and ranged between 0.73 and 1.75 and 0.04-0.2%, respectively. The statistical analysis revealed strong influence of fBC than fTOC on the distribution of PBDEs and DPs in the Indus River Basin soils. BDE's congener profile suggested the input of penta-bromodiphenylether (DE-71) commercial formulation in the study area. Soil-air partitioning of PBDEs were investigated by employing octanol-air partition coefficients (KOA) and black carbon-air partition coefficients (KBC-A). The results of both models suggested the combined influence of total organic carbon (absorption) and black carbon (adsorption) in the studied area. Copyright © 2015 Elsevier Ltd. All rights reserved.

Low-Cost Approach to the Design and Fabrication of a LOX/RP-1 Injector

NASA Technical Reports Server (NTRS)

Shadoan, Michael D.; Sparks, Dave L.; Turner, James E. (Technical Monitor)

2000-01-01

NASA Marshall Space Flight Center (MSFC) has designed, built, and is currently testing Fastrac, a liquid oxygen (LOX)/RP-1 fueled 60K-lb thrust class rocket engine. One facet of Fastrac, which makes it unique is that it is the first large-scale engine designed and developed in accordance with the Agency's mandated "faster, better, cheaper" (FBC) program policy. The engine was developed under the auspices of MSFC's Low Cost Boost Technology office. Development work for the main injector actually began in 1993 in subscale form. In 1996, work began on the full-scale unit approximately 1 year prior to initiation of the engine development program. In order to achieve the value goals established by the FBC policy, a review of traditional design practices was necessary. This internal reevaluation would ultimately challenge more conventional methods of material selection. design process, and fabrication techniques. The effort was highly successful. This "new way" of thinking has resulted in an innovative injector design, one with reduced complexity and significantly lower cost. Application of lessons learned during this effort to new or existing designs can have a similar effect on costs and future program successes.

Surface roughness of flowable resin composites eroded by acidic and alcoholic drinks

PubMed Central

Poggio, Claudio; Dagna, Alberto; Chiesa, Marco; Colombo, Marco; Scribante, Andrea

2012-01-01

Aim: The aim of this study is to evaluate the surface roughness of four flowable resin composites following exposure to acidic and alcoholic drinks. Materials and Methods: SureFil SDR flow, TetricEvoFlow, Esthet-X Flow and Amaris Flow HT samples were immersed in artificial saliva, Coca Cola and Chivas Regal Whisky. Each specimen was examined using a Leica DCM 3D microscope: Arithmetical mean height of the surface profiles was measured (Sa). Results: Kruskal-Wallis test showed significant differences among various groups (P<0,001). Mann Whitney test was applied and control groups showed significantly lower Sa values than other groups (P=0,008). Coca Cola groups showed highest Sa values (P<0,021). No significant differences (P=0,14) in surface texture were found among the specimens of the different materials. No significant differences were found among TetricEvoFlow, Esthet-X Flow and Amaris Flow under control conditions nor after Coca Cola application. Under control condition and after Coca Cola application SureFil SDR flow showed significantly higher Sa values. Moreover, after whisky application Amaris Flow showed significantly lower Sa values then the other three groups that showed no significant differences among them. Conclusions: Acidic and alcoholic drinks eroded the surface roughness of all evaluated flowable resin composites. PMID:22557811

Effect of compression pressure on inhalation grade lactose as carrier for dry powder inhalations

PubMed Central

Raut, Neha Sureshrao; Jamaiwar, Swapnil; Umekar, Milind Janrao; Kotagale, Nandkishor Ramdas

2016-01-01

Introduction: This study focused on the potential effects of compression forces experienced during lactose (InhaLac 70, 120, and 230) storage and transport on the flowability and aerosol performance in dry powder inhaler formulation. Materials and Methods: Lactose was subjected to typical compression forces 4, 10, and 20 N/cm2. Powder flowability and particle size distribution analysis of un-compressed and compressed lactose was evaluated by Carr's index, Hausner's ratio, the angle of repose and by laser diffraction method. Aerosol performance of un-compressed and compressed lactose was assessed in dispersion studies using glass twin-stage-liquid-impenger at flow rate 40-80 L/min. Results: At compression forces, the flowability of compressed lactose was observed same or slightly improved. Furthermore, compression of lactose caused a decrease in in vitro aerosol dispersion performance. Conclusion: The present study illustrates that, as carrier size increases, a concurrent decrease in drug aerosolization performance was observed. Thus, the compression of the lactose fines onto the surfaces of the larger lactose particles due to compression pressures was hypothesized to be the cause of these observed performance variations. The simulations of storage and transport in an industrial scale can induce significant variations in formulation performance, and it could be a source of batch-to-batch variations. PMID:27014618

Detailed studies of aviation fuel flowability

NASA Technical Reports Server (NTRS)

Mehta, H. K.; Armstrong, R. S.

1985-01-01

Six Jet A fuels, with varying compositions, were tested for low temperature flowability in a 190-liter simulator tank that modeled a section of a wing tank of a wide-body commercial airplane. The insulated tank was chilled by circulating coolant through the upper and lower surfaces. Flow-ability was determined as a function of fuel temperature by holdup, the fraction of unflowable fuel remaining in the tank after otherwise complete withdrawal. In static tests with subfreezing tank conditions, hold up varied with temperature and fuel composition. However, a general correlation of two or three classes of fuel type was obtained by plotting holdup as a function of the difference between freezing point and boundary-layer temperature, measured 0.6 cm above the bottom tank surface. Dynamic conditions of vibrations and slosh or rate of fuel withdrawal had very minor effects on holdup. Tests with cooling schedules to represent extreme, cold-day flights showed, at most, slight holdup for any combination of fuel type or dynamic conditions. Tests that superimposed external fuel heating and recirculation during the cooldown period indicates reduced hold up by modification of the low-temperature boundary layer. Fuel heating was just as effective when initiated during the later times of the tests as when applied continuously.

Selected physical and chemical properties of Feverfew (Tanacetum parthenium) extracts important for formulated product quality and performance.

PubMed

Jin, Ping; Madieh, Shadi; Augsburger, Larry L

2008-01-01

The objectives of this research are: (1) to assess selected formulation-relevant physical properties of several commercial Feverfew extracts, including flowability, hygroscopicity, compressibility and compactibility (2) to develop and validate a suitable extraction method and HPLC assay, and (3) to determine the parthenolide content of several commercial Feverfew extracts. Carr's index, minimum orifice diameter and particle-particle interaction were used to evaluate powder flowability. Hygroscopicity was evaluated by determining the equilibrium moisture content (EMC) after storage at various % relative humidities. Heckle analysis and compression pressure-radial tensile strength relationship were used to represent compression and compaction properties of feverfew extracts. An adapted analytical method was developed based on literature methods and then validated for the determination of parthenolide in feverfew. The commercial extracts tested exhibited poor to very poor flowability. The comparatively low mean yield pressure suggested that feverfew extracts deformed mainly plastically. Hygroscopicity and compactibility varied greatly with source. No commercial feverfew extracts tested contained the label claimed parthenolide. Even different batches from the same manufacturer showed significantly different parthenolide content. Therefore, extract manufactures should commit to proper quality control procedures that ensure accurate label claims, and supplement manufacturers should take into account possible differences in physico-chemical properties when using extracts from multiple suppliers.

Evaluation of degree of conversion and the effect of thermal aging on the color stability of resin cements and flowable composite.

PubMed

Prieto, Lúcia Trazzi; Pimenta de Araújo, Cíntia Tereza; Araujo Pierote, Josué Junior; Salles de Oliveira, Dayane Carvalho Ramos; Coppini, Erick Kamiya; Sartini Paulillo, Luís Alexandre Maffei

2018-01-01

The aim of this in vitro study was to evaluate the color stability and degree of conversion (DC) of dual-cure and light-cure cements and flowable composites after thermal aging. A total of 50 human incisors were prepared and divided into six groups ( n = 10). Veneers were fabricated using IPS Empress Direct composite resin were bonded with three types of luting agents: Light-cured, conventional dual, and flowable composite according to the manufacturer's instructions. The groups were as follows: Filtek Z350XT Flow/Single Bond 2, RelyX ARC/Single Bond 2, RelyX Veneer/Single Bond 2, Tetric N-Flow/Tetric N-Bond, and Variolink II/Tetric N-Bond. Commission Internationale de l'Éclairage L*, a* and b* color coordinates were measured 24 h after cementation procedure with a color spectrophotometer and reevaluated after 10,000 thermal cycles. To evaluate the DC 50 specimens ( n = 10) of each resin material were obtained and Fourier transform infrared spectroscopy was used to evaluate the absorption spectra. Statistical analysis was performed with one-way ANOVA and Tukey's test (α = 0.05). No statistically significant differences in ΔE* occurred after aging. The greatest change in lightness occurred in the Variolink II resin cement. Changes in red-green hue were very small for the same cement and largest in the Tetric N-Flow flowable resin composite, while the greatest change in blue-yellow hue was a yellowing of the RelyX ARC luting cement. RelyX ARC exhibited the highest DC, and there were no statistically significant differences in DC among the other cements. Resin-based luting agent might affect the final of ceramic veneer restorations. The thermal aging affected the final color of the evaluated materials, and these were regarded as clinically unacceptable (ΔE >3.3).

Evaluating the Microshear Bond Strength and Microleakage of Flowable Composites Containing Zinc Oxide Nano-particles.

PubMed

Teymoornezhad, Koorosh; Alaghehmand, Homayoun; Daryakenari, Ghazaleh; Khafri, Soraya; Tabari, Mitra

2016-11-01

Preventive resin restorations (PRR) are the conservative choice for the most common carious lesions in children. Thus, new age flowable resin composites with higher filler content are readily used. The aim of this study was to evaluate the microshear bond strength and microleakage of two flowable resin composites containing different percentages of nano zinc oxide (NZnO) particles, which have proven to have antimicrobial properties. This experimental in-vitro study was carried out in the Dental Material Research Center of Babol University of Medical Sciences in 2015. One nanohybrid and one nanofill flowable resin composite were chosen and modified with the incorporation of 1% and 3% Wt NZnO particles. Six groups (n=10, 0%, 1%, and 3%) of resin composite sticks on dental enamel (2×2mm) were prepared to be placed in the microtensile tester. The microshear bond strength magnitude (MPa) was recorded at the point of failure. A class I box (3×0.8×1 mm) was prepared on 60 premolars and filled using the resin composites (6 groups, n=10). The specimens were immersed in a 5% basic fuschin solution and sectioned bucco-lingually to view the microleakage using a stereomicroscope. One-way ANOVA and Tukey tests for microshear and Wilcoxon and Kruskal-Wallis tests for microleakage were used to analyze the data in the IBM SPSS Statistics version 22 software. The bond strength of the 3% clearfill group significantly decreased while no significant change occurred in the bond strength in other groups. The Z-350 group had significantly lower microleakage as nanoparticles increased. No significant difference was observed in the clearfill group. Up to 3% Wt incorporation of NZnO particles will not diversely alter the bond strength, but it will be beneficial in providing antimicrobial effects with lower microleakage rates.

UNDERGROUNG PLACEMENT OF COAL PROCESSING WASTE AND COAL COMBUSTION BY-PRODUCTS BASED PASTE BACKFILL FOR ENHANCED MINING ECONOMICS

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

Y.P. Chugh; D. Biswas; D. Deb

2002-06-01

This project has successfully demonstrated that the extraction ratio in a room-and-pillar panel at an Illinois mine can be increased from the current value of approximately 56% to about 64%, with backfilling done from the surface upon completion of all mining activities. This was achieved without significant ground control problems due to the increased extraction ratio. The mined-out areas were backfilled from the surface with gob, coal combustion by-products (CCBs), and fine coal processing waste (FCPW)-based paste backfill containing 65%-70% solids to minimize short-term and long-term surface deformations risk. This concept has the potential to increase mine productivity, reduce miningmore » costs, manage large volumes of CCBs beneficially, and improve the miner's health, safety, and environment. Two injection holes were drilled over the demonstration panel to inject the paste backfill. Backfilling was started on August 11, 1999 through the first borehole. About 9,293 tons of paste backfill were injected through this borehole with a maximum flow distance of 300-ft underground. On September 27, 2000, backfilling operation was resumed through the second borehole with a mixture of F ash and FBC ash. A high-speed auger mixer (new technology) was used to mix solids with water. About 6,000 tons of paste backfill were injected underground through this hole. Underground backfilling using the ''Groutnet'' flow model was simulated. Studies indicate that grout flow over 300-foot distance is possible. Approximately 13,000 tons of grout may be pumped through a single hole. The effect of backfilling on the stability of the mine workings was analyzed using SIUPANEL.3D computer program and further verified using finite element analysis techniques. Stiffness of the backfill mix is most critical for enhancing the stability of mine workings. Mine openings do not have to be completely backfilled to enhance their stability. Backfill height of about 50% of the seam height is adequate to minimize surface deformations. Freeman United Coal Company performed engineering economic evaluation studies for commercialization. They found that the costs for underground management at the Crown III mine would be slightly higher than surface management at this time. The developed technologies have commercial potential but each site must be analyzed on its merit. The Company maintains significant interest in commercializing the technology.« less

[Solidification of magnolol phospholipid complex with polyvingypyrrolidone].

PubMed

Dai, Yun-Hao; Wang, Man; Ju, Jian-Ming; Zhang, Zhen-Hai

2016-06-01

In this study, magnolol phospholipid complex (MPC) was prepared and solidified with polyvingypyrrolidone (PVPP). The influence of PVPP on MPC's flowability, dissolution and oral bioavailability was investigated. The results of phase characterization using differential scanning calorimetry (DSC), infrared spectroscopy (IR), and scanning electron microscopy (SEM) showed that magnolol existed in solidified powder and MPC in an amorphous state. In flowability and dissolution experiments, solidified powder showed significant superiority. At the same time, it showed a higher oral bioavailability compared with MPC, with AUC0-∞ of 73.47 μg•h•mL⁻¹ vs. 63.48 μg•h•mL⁻¹. This process for solidifying powder with PVPP is simple and convenient. Copyright© by the Chinese Pharmaceutical Association.

FIST and the Analytical Hierarchy Process: Comparative Modeling

DTIC Science & Technology

2013-03-01

one mission to the moon, three space telescopes, two comet and asteroid rendezvous, four Earth-orbiting satellites, and one ion propulsion test...vehicle” (Ward, 2010:50). One successful mission example from FBC is the Near Earth Asteroid Rendezvous (NEAR) project that launched in 1996. The...transportation, power, energy, community development, water, mining , and environment. Respondents from PB have managed such programs as the $2.5 billion

76 FR 38178 - Change in Bank Control Notices; Acquisitions of Shares of a Bank or Bank Holding Company

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-29

..., New York, New York 10045-0001: 1. Thomas H. Lee (Alternative) Fund VI, L.P., Thomas H. Lee (Alternative) Parallel Fund VI, L.P., Thomas H. Lee (Alternative) Parallel (DT) Fund VI, L.P., THL FBC Equity Investors, L.P., THL Advisors (Alternative) VI, L.P., Thomas H. Lee (Alternative) VI, Ltd., THL Managers VI...

Crystal coating via spray drying to improve powder tabletability.

PubMed

Vanhoorne, V; Peeters, E; Van Snick, B; Remon, J P; Vervaet, C

2014-11-01

A continuous crystal coating method was developed to improve both flowability and tabletability of powders. The method includes the introduction of solid, dry particles into an atomized spray during spray drying in order to coat and agglomerate individual particles. Paracetamol was used as a model drug as it exhibits poor flowability and high capping tendency upon compaction. The particle size enlargement and flowability were evaluated by the mean median particle size and flow index of the resulting powders. The crystal coating coprocessing method was successful for the production of powders containing 75% paracetamol with excellent tableting properties. However, the extent of agglomeration achieved during coprocessing was limited. Tablets compressed on a rotary tablet press in manual mode showed excellent compression properties without capping tendency. A formulation with 75% paracetamol, 5% PVP and 20% amorphous lactose yielded a tensile strength of 1.9 MPa at a compression pressure of 288 MPa. The friability of tablets compressed at 188 MPa was only 0.6%. The excellent tabletability of this formulation was attributed to the coating of paracetamol crystals with amorphous lactose and PVP through coprocessing and the presence of brittle and plastic components in the formulation. The coprocessing method was also successfully applied for the production of directly compressible lactose showing improved tensile strength and friability in comparison to a spray dried direct compression lactose grade.

Leaching of FGD Byproducts Using a CSTX

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

Kairies, C.L.; Schroeder, K.T.; Cardone, C.R.

2005-09-01

Leaching studies of coal utilization byproducts (CUB) are often performed to determine the compatibility of the material in a particular end-use or disposal environment. Typically, these studies are conducted using either a batch or a fixed-bed column technique. Fixed-bed columns offer the advantage of a continuous flow of effluent that provides elution profiles with changing elution volume and pH. Unfortunately, clogs can form in fixed-bed leaching columns, either because of cementitious properties of the material itself, such as is seen for fluidized bed combustion (FBC) fly ash, or because of precipitate formation, such as can occur when a high-calcium ashmore » is subjected to sulfate-containing leachates. Also, very fine-grained materials, such as gypsum, do not provide sufficient permeability for study in a fixed-bed column. A continuous, stirred-tank extractor (CSTX) is being used as an alternative technique that can provide the elution profile of column leaching but without the low permeability problems. The CSTX has been successfully employed in the leaching of flue gas desulfurization products that would not be sufficiently permeable under traditional column leaching conditions. The results indicate that the leaching behavior depends on a number of factors, including (but not limited to) solubility and neutralization capacity of the mineral phases present, sorption properties of these phases, behavior of the solubilized material in the tank, and the type of species in solution. In addition, leaching to near-exhaustion of a wallboard produced from FGD gypsum has allowed the isolation of a highly adsorptive phase. This phase appears to be present in at least some FGD gypsums and accounts for the immobilization of trace metals such as arsenic, cobalt, lead, and mercury.« less

Dry powder segregation and flowability: Experimental and numerical studies

NASA Astrophysics Data System (ADS)

Ely, David R.

Dry powder blending is a very important industrial and physical process used in the production of numerous pharmaceutical dosage forms such as tablets, capsules, and dry powder aerosols. Key aspects of this unit operation are process monitoring and control. Process control is particularly difficult due to the complexity of particle-particle interactions, which arise from the adhesion/cohesion characteristics of interfaces and morphological characteristics such as particle size, shape, and dispersity. The effects of such characteristics need to be understood in detail in order to correlate individual particle properties to bulk powder properties. The present dissertation numerically and experimentally quantifies the mixing process to rationalize particle-particle interactions. In particular, near infrared spectroscopy (NIRS) was used to non-invasively characterize in real-time the blending processes and thus investigate the dynamics of blending under different operating conditions. A novel image analysis technique was developed to quantify the scale of segregation from images obtained non-destructively via near infrared chemical imaging (NIR-CI). Although NIR-CI data acquisition times are too long for real-time data collection, NIR-CI has an advantage, in that it provides the spatial distribution of the drug. Therefore, NIRS and NIR-CI are complementary techniques for investigating the complex process of blending dry powders and assessing end-product quality. Additionally, the discrete element method was used to investigate the effect of powder cohesion on the packing fraction. Simulations indicated an exponential relationship between the random loose packing fraction and cohesive forces. Specifically, the packing fraction decreased asymptotically with increased ratio of cohesive force to particle weight. Thus, increasing this force ratio above a critical value has negligible impact on the packing fraction. Such result directly impacts the Hausner ratio flowability measurement, which is directly related to the packing fraction. Two commonly used tests were compared to assess their utility: the rotational split-cell shear cell test and the Hausner ratio. The Hausner ratio proved to be better suited for characterizing the flowability of unconsolidated powders than the splitring shear cell. Results demonstrate that the optimal flowability test depends on the powder properties and the environment under which flow will be induced.

Polymerization stress evolution of a bulk-fill flowable composite under different compliances.

PubMed

Guo, Yongwen; Landis, Forrest A; Wang, Zhengzhi; Bai, Ding; Jiang, Li; Chiang, Martin Y M

2016-04-01

To use a compliance-variable instrument to simultaneously measure and compare the polymerization stress (PS) evolution, degree of conversion (DC), and exotherm of a bulk-fill flowable composite to a packable composite. A bulk-fill flowable composite (Filtek Bulk-fill, FBF) and a conventional packable composite (Filtek Z250, Z250) purchased from 3M ESPE were investigated. The composites were studied using a cantilever-beam based instrument equipped with an in situ near infrared (NIR) spectrometer and a microprobe thermocouple. The measurements were carried out under various instrumental compliances (ranging from 0.3327μm/N to 12.3215μm/N) that are comparable to the compliances of clinically prepared tooth cavities. Correlations between the PS and temperature change as well as the DC were interpreted. The maximum PS of both composites at 10min after irradiation decreased with the increase in the compliance of the cantilever beam. The FBF composite generated a lower final stress than the Z250 sample under instrumental compliances less than ca. 4μm/N; however, both materials generated statistically similar PS values at higher compliances. The reaction exotherm and the DC of both materials were found to be independent of compliance. The DC of the FBF sample was slightly higher than that of the packable Z250 composite while the peak exotherm of FBF was almost double that of the Z250 composite. For FBF, a characteristic drop in the PS was observed during the early stage of polymerization for all compliances studied which was not observed in the Z250 sample. This drop was shown to relate to the greater exotherm of the less-filled FBF sample relative to the Z250 composite. While the composites with lower filler content (low viscosity) are generally considered to have lower PS than the conventional packable composites, a bulk-fill flowable composite was shown to produce lower PS under a lower compliance of constraint as would be experienced if the composite was used as the base material in clinical procedures. Published by Elsevier Ltd.

Characterization of Structural Rebuilding and Shear Migration in Cementitious Materials in Consideration of Thixotropy

NASA Astrophysics Data System (ADS)

Qian, Ye

Characterization of structural rebuilding and shear migration in cementitious materials in consideration of thixotropy Ye Qian From initial contact with water until hardening, and deterioration, cement and concrete materials are subjected to various chemical and physical transformations and environmental impacts. This thesis focuses on the properties during the fresh state, shortly after mixing until the induction period. During this period flow history, including shearing and resting, and hydration both play big roles in determining the rheological properties. The rheological properties of cement and concrete not only affect the casting and pumping process, but also very critical for harden properties and durability properties. Compared with conventional concrete, self-consolidating concrete (SCC) can introduce many advantages in construction application. These include readiness to apply, decreasing labor necessary for casting, and enhancing hardened properties. However, challenges still remain, such as issues relating to formwork pressure and multi-layer casting. Each of these issues is closely related to the property of thixotropy. From the microstructural point of view, thixotropy is described as structural buildup (flocculation) under rest and breakdown (deflocculation) under flow. For SCC, as well as other concrete systems, it is about balancing sufficient flowability during casting and rate of structural buildup after placement for the application at hand. For instance, relating to the issue of SCC formwork, it is ideal for the material to be highly flowable to achieve rapid casting, but then exhibit high rate of structural buildup to reduce formwork pressure. This can reduce the cost of formwork and reduce the risk of formwork failure. It is apparent that accurately quantifying the two aspects of thixotropy, i.e. structuration and destructuration, is key to tackling these challenges in field application. Thus, the overall objective of my doctoral study is to improve quantification of key parameters tied to thixotropy that we have identified to be important: static yield stress, cohesion and degree of shear-induced particle migration. The two main contributions are as follows: Firstly, I quantified structuration of fresh paste and mortar systems by measuring static yield stress. After an extensive review of various rheological methods to probe viscoelastic properties of yield stress fluids, I selected, developed, and implemented a creep recovery protocol. Creep results were supplemented by low-amplitude oscillatory shear results, and supported that the measured static yield stress corresponds to the solid-liquid transition. This improved quantification of static yield stress can help better understand the effect of mix composition on SCC formwork pressure development, as well as static segregation and stability. Since the static yield stress is measured before the structure is broken down, the effects of sand migration are eliminated. This study also analyzed effects of other supplementary cementitous materials such as nanoclay and fly ash. Results showed that nanoclay effectively increases static yield stress and structuration rate, while fly ash decreases static yield stress. To complement this investigation, I studied cohesion using the probe tack test, as cohesion is widely cited to be closely related to formwork pressure. I verified that probe tack test is a quick and useful method to measure static cohesion. Results showed that nanoclay increased cohesion dramatically while fly ash did not have an apparent effect on cohesion. Secondly, I developed an empirical model to fit the stress decay process under constant shear rate, For mortar systems, the stress decay can be attributed to two mechanisms: colloidal destructuration and sand migration. Such a model could be used to characterize particle migration and dynamic segregation, a critical issue for casting applications. In addition, shear induced particle migration is a widely recognized challenge in characterizing mortars and concretes through shear rheological methods. Therefore this model can help determine the range of shear rates within which migration can be minimized to guide the design of protocols for dynamic rheological characterization and to ultimately develop design strategies to minimize mitigation. Compared with currently existing methods, this model provides a faster approach to quantify the sand migration process, including kinetics.

Physical properties and biological effects of mineral trioxide aggregate mixed with methylcellulose and calcium chloride.

PubMed

Lee, Bin-Na; Chun, Soo-Ji; Chang, Hoon-Sang; Hwang, Yun-Chan; Hwang, In-Nam; Oh, Won-Mann

2017-01-01

Methylcellulose (MC) is a chemical compound derived from cellulose. MTA mixed with MC reduces setting time and increases plasticity. This study assessed the influence of MC as an anti-washout ingredient and CaCl2 as a setting time accelerator on the physical and biological properties of MTA. Test materials were divided into 3 groups; Group 1(control): distilled water; Group 2: 1% MC/CaCl2; Group 3: 2% MC/CaCl2. Compressive strength, pH, flowability and cell viability were tested. The gene expression of bone sialoprotein (BSP) was detected by RT-PCR and real- time PCR. The expression of alkaline phosphatase (ALP) and mineralization behavior were evaluated using an ALP staining and an alizarin red staining. Compressive strength, pH, and cell viability of MTA mixed with MC/CaCl2 were not significantly different compared to the control group. The flowability of MTA with MC/CaCI2 has decreased significantly when compared to the control (p<.05). The mRNA level of BSP has increased significantly in MTA with MC/CaCl2 compared to the control (p<.05). This study revealed higher expression of ALP and mineralization in cells exposed to MTA mixed with water and MTA mixed with MC/CaCl2 compared to the control (p<.05). MC decreased the flowability of MTA and did not interrupt the physical and biological effect of MTA. It suggests that these cements may be useful as a root-end filling material.

Self-consolidating concrete (SCC) for infrastructure elements.

DOT National Transportation Integrated Search

2012-09-01

Because of its unique nature, self-consolidating concrete (SCC) has the potential to significantly reduce costs associated with : transportation-related infrastructure, benefiting both MoDOT and the residents of Missouri. SCC is a highly flowable, no...

Self-consolidating concrete (SCC) for infrastructure elements.

DOT National Transportation Integrated Search

2012-07-01

Because of its unique nature, self-consolidating concrete (SCC) has the potential to significantly reduce costs associated with : transportation-related infrastructure, benefiting both MoDOT and the residents of Missouri. SCC is a highly flowable, : ...

Lime-Based Sorbents for High-Temperature CO2 Capture—A Review of Sorbent Modification Methods

PubMed Central

Manovic, Vasilije; Anthony, Edward J.

2010-01-01

This paper presents a review of the research on CO2 capture by lime-based looping cycles undertaken at CanmetENERGY’s (Ottawa, Canada) research laboratories. This is a new and very promising technology that may help in mitigation of global warming and climate change caused primarily by the use of fossil fuels. The intensity of the anticipated changes urgently requires solutions such as more cost-effective technologies for CO2 capture. This new technology is based on the use of lime-based sorbents in a dual fluidized bed combustion (FBC) reactor which contains a carbonator—a unit for CO2 capture, and a calciner—a unit for CaO regeneration. However, even though natural materials are cheap and abundant and very good candidates as solid CO2 carriers, their performance in a practical system still shows significant limitations. These limitations include rapid loss of activity during the capture cycles, which is a result of sintering, attrition, and consequent elutriation from FBC reactors. Therefore, research on sorbent performance is critical and this paper reviews some of the promising ways to overcome these shortcomings. It is shown that reactivation by steam/water, thermal pre-treatment, and doping simultaneously with sorbent reforming and pelletization are promising potential solutions to reduce the loss of activity of these sorbents over multiple cycles of use. PMID:20948952

Protecting tree roots and subterranean infrastructure in urban areas by developing self-compacting flowable fills with root growth impeding properties

NASA Astrophysics Data System (ADS)

Felde, Vincent; Simon, Jana; Kimm-Friedenberg, Stefan; Peth, Stephan; Middendorf, Bernhard

2015-04-01

In urban areas, the installation of cables and disposal lines is still done by open building method. Here, a ditch is being excavated, pipes and lines are laid and subsequently it is filled with and covered by bulk material (e.g. sand or gravel), which is then compacted. Due to the often times limited space that the roots have in the ground and the better supply of water and oxygen in the poorly compacted bulk material, these refilled ditches are areas of preferential root growth of urban trees. The entangling of the pipes and supply lines by these roots leads to severe damage of the tree when maintenance work on the lines is carried out and roots have to be cut. In order to reduce this competition between urban trees and urban subterranean infrastructure, the development of a self-compacting flowable fill with root growth resistance is mandatory. Physico-chemical properties, such as a very high pH-value and a low cation-exchange-capacity, a low root-penetrability, a high packing density and a low porosity, with a poorly connected pore system that impedes gas and water exchange are the characteristic aspects of this flowable fills that could help avoid undesired root penetration into supply lines. The flowable fills are supposed to sheath pipes and lines void-free and without any tension, in order to restrain the root growth in these areas. Trees are of crucial importance for urban ecosystems and are comprising 3% of the total stock of trees in the Federal Republic of Germany, which is why it is fundamental to conserve them. This work therefore targets not only at enabling a balanced coexistence of urban trees and subterranean infrastructure, but also at avoiding costly re-opening of ditches, tree harming cutting of roots and time consuming maintenance work. Further positive side effects are reduced costs for network providers and local municipalities, as well as reduced noise and dust emissions for passersby and local residents. To guarantee the root growth restricting properties, the self-compacting fill has to have less porosity than the adjacent soil (40 - 60%). Theoretically a porosity of 30% is possible with a homogeneous compaction of sand. In urban areas, however, because of the limited spaces and crossing pipes, a mechanical and homogenous compacting is often impossible. Porosities of 60 to 70% are the result. Self-compacting flowable fills have a porosity of about 40% while the first optimized materials can even have a porosity of 28%. We present the first results of the hydro-mechanical properties of the different materials under development that highlight the influence of the mixture of the fills (i.e. maximal grain size) on the root growth impeding properties, while still ensuring mechanical workability of the material (in spite of the low porosity, strengths less than 0.8 N mm-² must be ensured at all times).

Surface and microstructural properties of photocatalytic cements for pavement applications.

DOT National Transportation Integrated Search

2016-10-01

Thin concrete inlays incorporating flowable fibrous concrete (FFC) mix designs as well as titanium dioxide (TiO2)- containing photocatalytic cements are a promising pavement preservation solution. These multi-functional inlays offer enhanced construc...

Effects of different crumb rubber sizes on the flowability and compressive strength of hybrid fibre reinforced ECC

NASA Astrophysics Data System (ADS)

Khed, Veerendrakumar C.; Mohammed, Bashar S.; Fadhil Nuruddin, Muhd

2018-04-01

The different sizes of crumb rubber have been used to investigate the effects on flowability and the compressive strength of the hybrid fibre reinforced engineered cementitious composite. Two sizes of crumb rubber 30 mesh and 1 to 3mm were used in partial replacement with the fine aggregate up to 60%. The experimental study was carried out through mathematical and statistical analysis by response surface methodology (RSM) using the Design Expert software. The response models have been developed and the results were validated by analysis of variance (ANOVA). It was found that finer sized crumb rubber inclusion had produced better workability and higher compressive strength when compared to the larger size and it was concluded that crumb rubber has negative effect on compressive strength and positive effect on workability. The optimization results are found to an approximately good agreement with the experimental results.

Massing in high shear wet granulation can simultaneously improve powder flow and deteriorate powder compaction: a double-edged sword.

PubMed

Shi, Limin; Feng, Yushi; Sun, Changquan Calvin

2011-05-18

The influence of massing during high shear wet granulation (HSWG) process on granule properties and performance was investigated using microcrystalline cellulose (MCC). Massing time varied from 0 to 40 min while other factors were fixed. Granule physical properties, including morphology, size, porosity, and specific surface area (SSA), were characterized. Changes in powder properties were profound in the first 10 min of massing but negligible beyond 10 min. With 10 min of massing, granule tabletability decreased by 75% while flowability increased by 75%. The significantly deteriorated tabletability and improved flowability resulted from dramatic changes in granule morphology, porosity, and SSA. The results confirm that massing time is a key process parameter in HSWG, and it must be carefully evaluated and controlled during process development, scale up, and manufacturing. Copyright © 2011 Elsevier B.V. All rights reserved.

Aggregate assesment and durability evaluation of optimized graded concrete in the state of Oklahoma

NASA Astrophysics Data System (ADS)

Ghaeezadeh, Ashkan

This research is a part of a larger project that emphasizes on creating a more scientific approach to designing concrete mixtures for concrete pavements that use less cement and more aggregate which is called optimized graded concrete. The most challenging obstacle in optimized mixtures is reaching enough workability so that one doesn't have to add more cement or super-plasticizer to reach the desired level of flowability. Aggregate gradation and characteristics have found to be very important when it comes to the workabaility of optimized graded concrete. In this research a new automated method of aggregate assessment was used to compare the shape and the surface of different aggregates as well as their influence on the concrete flowability. At the end, the performance of optimized graded concrete against drying shrinkage and freezing and thawing condition were investigated.

Morphological diversity of nitroguanidine crystals with enhanced mechanical performance and thermodynamic stability

NASA Astrophysics Data System (ADS)

Luo, Zhilong; Cui, Yingdan; Dong, Weibing; Xu, Qipeng; Zou, Gaoxing; Kang, Chao; Hou, Baohong; Chen, Song; Gong, Junbo

2017-12-01

Nitroguanidine (NQ) is a commonly used explosive, which has been widely used for both civilian and military explosive applications. However, the weak flowability and mechanical performance limit its application. In this work, mechanical performance and thermodynamic stability of NQ crystals were improved by controlling crystal morphologies in the crystallization process. Typical NQ crystals with multiple morphologies and single crystal form were obtained in the presence of additives during the cooling crystallization. The morphology controlled NQ crystals showed higher density, unimodal crystal size distribution and enhanced flowability. The additives showed the inhibitory effect on the nucleation of NQ crystals by in-situ FBRM and PVM determination, and the mechanism was analyzed by means of morphological prediction and molecular simulation. Furthermore, the morphology controlled NQ crystals suggested higher thermodynamic stability according to the calculation of entropy, enthalpy, Gibbs free energy and apparent activation energy on the basis of DSC results.

The effect of different beverages on the color and translucency of flowable composites.

PubMed

Karadas, Muhammet

2016-11-01

This study examined the changes in color and translucency of flowable composites after immersion in different beverages. Thirty composite samples were prepared from four flowable composites (G-aenial Universal Flo, Filtek Ultimate, Esthelite Flow Quick, and Clearfil Majesty ES Flow) and a microhybrid composite (Filtek Z-250) and stored in distilled water at 37°C for 24 h. The samples were randomly divided into seven groups and then immersed in different beverages (Red Bull, coffee, black tea, Pepsi Cola, orange juice, and distilled water) for 7 days. The CIE L*a*b* values of each sample were measured against white and black backgrounds using a spectrophotometer before and after immersion. Data were analyzed using two-way analysis of variance and Tukey's post-hoc test (p < 0.05). The color changes were significantly different among the composite materials after immersion in beverages (p < 0.05). Filtek Ultimate and Esthelite Flow Quick exhibited less discoloration than did G-aenial Universal Flo and Clearfil Majesty ES Flow. No significant difference was found between Filtek Z-250 and either Filtek Ultimate or Esthelite Flow Quick (p > 0.05). Among the beverages, black tea and coffee caused the highest discoloration of all the materials. Immersion in coffee and black tea resulted in the highest negative changes in the translucency of the materials. The degree of discoloration for the composite resins depended on the material used and drinking beverage. SCANNING 38:701-709, 2016. © 2016 Wiley Periodicals, Inc. © Wiley Periodicals, Inc.

Rheological properties of experimental Bis-GMA/TEGDMA flowable resin composites with various macrofiller/microfiller ratio.

PubMed

Beun, Sébastien; Bailly, Christian; Dabin, Anne; Vreven, José; Devaux, Jacques; Leloup, Gaëtane

2009-02-01

The purpose of this study was to investigate the rheological behavior of resin composites and to evaluate the influence of each component, organic as well as inorganic, on their viscoelastic properties by testing model experimental formulations. Several unfilled mixtures of 2,2-bis-[4-(methacryloxy-2-hydroxy-propoxy)-phenyl]-propane (Bis-GMA) and triethylene glycol dimethacrylate (TEGDMA) were prepared as well as experimental flowable resin composites using a Bis-GMA/TEGDMA 50/50 wt% mixture as organic fraction filled at 60% in weight with varying ratios of silanated barium glass (1 microm) and partially hydrophobic fumed silica (0.1 microm). Their rheological properties were investigated using dynamic oscillatory rheometers. Transmission electron microscopy (TEM) was also performed to investigate the spatial organization of the filler particles. Unfilled Bis-GMA/TEGDMA mixtures all showed a Newtonian behavior. The experimental flowable resin composites were non-Newtonian, shear-thinning fluids. As the quantity of microfiller increased, the viscosity increased and the shear-thinning behavior increased as well. In addition, the experimental composites showed thixotropy, i.e. their viscosity is a function of time after deformation. All these properties were not specifically linked to the creation and destruction of a visible network between inorganic particles, as no difference could be seen between particles' spatial organization at the equilibrium rest state or immediately after deformation. The complex viscoelastic properties of resin composites are due to interactions between microfiller and monomer molecules. Modifying the chemical and physical properties of the particles' surface could possibly improve their flow properties and thus their clinical handling performances.

Development of Coprocessed Chitin-Calcium Carbonate as Multifunctional Tablet Excipient for Direct Compression.

PubMed

Chaheen, Mohammad; Sanchez-Ballester, Noelia M; Bataille, Bernard; Yassine, Ahmad; Belamie, Emmanuel; Sharkawi, Tahmer

2018-04-24

Owing to the increasing interest in multifunctional excipients for tableting, coprocessing of individual excipients is regularly used to produce excipients of improved multifunctionality superior to individual excipients or their physical mix. The use of chitin as an excipient in tablet formulation is limited because of certain drawbacks such as poor flowability and low true density. The objective of this work is to improve these properties through coprocessing of chitin with calcium carbonate (CaCO 3 ) by precipitating CaCO 3 on chitin particles using different methods. In addition, optimization of the coprocessed chitin was carried out to improve the excipient's properties. Physicochemical (CaCO 3 content, true density, X-ray diffraction, infrared spectroscopy, and scanning electron microscopy) and functional testing (swelling force, flowability, tensile strength, deformation mechanism, and disintegration time) were used to characterize the coprocessed product. Results showed that the calcite CaCO 3 polymorph is precipitated on the chitin surface and that it interacts with chitin at carbonyl- and amide-group level. In addition, the coprocessed excipient has an improved true density and powder flowability, with CaCO 3 forming single layer on the chitin particles surface. Tableting studies showed that the coprocessed powder exhibited an intermediate deformation behavior between CaCO 3 (most brittle) and chitin (most plastic). Tablets showed acceptable tensile strength and rapid disintegration (2-4 s). These results show the potential use of coprocessed chitin-CaCO 3 as a multifunctional excipient for fast disintegration of tablets produced by direct compression. Copyright © 2018 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Multi-layer laminate structure and manufacturing method

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

Keenihan, James R; Cleereman, Robert J; Eurich, Gerald

2012-04-24

The present invention is premised upon a multi-layer laminate structure and method of manufacture, more particularly to a method of constructing the multi-layer laminate structure utilizing a laminate frame and at least one energy activated flowable polymer.

Multi-layer laminate structure and manufacturing method

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

Keenihan, James R.; Cleereman, Robert J.; Eurich, Gerald

2013-01-29

The present invention is premised upon a multi-layer laminate structure and method of manufacture, more particularly to a method of constructing the multi-layer laminate structure utilizing a laminate frame and at least one energy activated flowable polymer.

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.

Report A : self-consolidating concrete (SCC) for infrastructure elements - shear characteristics.

DOT National Transportation Integrated Search

2012-08-01

Because of its unique ability to maintain high flow-ability and remain homogeneous, : self-consolidating concrete (SCC) has the potential to significantly reduce the costs : associated with civil infrastructure; however, the use of higher paste and l...

Design and application of low compaction energy concrete for use in slip-form concrete paving.

DOT National Transportation Integrated Search

2009-01-01

Slipform self-consolidating concrete (SFSCC) requires sufficient flowability in order to consolidate without the use of internal vibration. However, this concrete must also gain sufficient green strength in order to keep its shape immediately after s...

Low temperature fuel behavior studies

NASA Technical Reports Server (NTRS)

Stockemer, F. J.

1980-01-01

Aircraft fuels at low temperatures near the freezing point. The principal objective was an improved understanding of the flowability and pumpability of the fuels in a facility that simulated the heat transfer and temperature profiles encountered during flight in the long range commercial wing tanks.

Spacecraft operations automation: Automatic alarm notification and web telemetry display

NASA Astrophysics Data System (ADS)

Short, Owen G.; Leonard, Robert E.; Bucher, Allen W.; Allen, Bryan

1999-11-01

In these times of Faster, Better, Cheaper (FBC) spacecraft, Spacecraft Operations Automation is an area that is targeted by many Operations Teams. To meet the challenges of the FBC environment, the Mars Global Surveyor (MGS) Operations Team designed and quickly implemented two new low-cost technologies: one which monitors spacecraft telemetry, checks the status of the telemetry, and contacts technical experts by pager when any telemetry datapoints exceed alarm limits, and a second which allows quick and convenient remote access to data displays. The first new technology is Automatic Alarm Notification (AAN). AAN monitors spacecraft telemetry and will notify engineers automatically if any telemetry is received which creates an alarm condition. The second new technology is Web Telemetry Display (WTD). WTD captures telemetry displays generated by the flight telemetry system and makes them available to the project web server. This allows engineers to check the health and status of the spacecraft from any computer capable of connecting to the global internet, without needing normally-required specialized hardware and software. Both of these technologies have greatly reduced operations costs by alleviating the need to have operations engineers monitor spacecraft performance on a 24 hour per day, 7 day per week basis from a central Mission Support Area. This paper gives details on the design and implementation of AAN and WTD, discusses their limitations, and lists the ongoing benefits which have accrued to MGS Flight Operations since their implementation in late 1996.

Efficacy and safety of botulinum toxin injection for interstitial cystitis/bladder pain syndrome: a systematic review and meta-analysis.

PubMed

Shim, Sung Ryul; Cho, Young Joo; Shin, In-Soo; Kim, Jae Heon

2016-08-01

To investigate the overall treatment efficacy and safety of botulinum toxin type A (BoNTA) injections compared with placebo in interstitial cystitis/bladder pain syndrome (IC/BPS). We conducted a systematic review and meta-analysis of the published literature in PubMed, Cochrane Library, and EMBASE on BoNTA use in IC/BPS. Outcome measures included changes of OLS, ICSI, ICPI, VAS, frequency, nocturia, FBC, Qmax, and PVR from baseline and also included adverse events. A total of five studies were included, with a total sample size of 252 subjects (133 subjects in the experimental group and 119 subjects in the control group). The duration of follow-up ranged from 8 to 12 weeks. The BoNTA dosage was from 50 to 200 U. The pooled overall SMD in the mean change of VAS for the BoNTA group versus the placebo group was -0.49 (95 % CI -0.74, -0.23). There were also significant improvements in ICPI and frequency. The other outcomes (ICSI, nocturia, Qmax, and FBC) were not statistically different between the two groups. Although BoNTA is not regulatory approved indication, this first evidence-based systematic review and meta-analysis of BoNTA injection for IC/BPS showed significant differences in efficacy of treatment compared with placebo, especially for pain control, and also showed no differences in the rate of procedure-related adverse events.

Transforming from planar to three-dimensional lithium with flowable interphase for solid lithium metal batteries

PubMed Central

Liu, Yayuan; Lin, Dingchang; Jin, Yang; Liu, Kai; Tao, Xinyong; Zhang, Qiuhong; Zhang, Xiaokun; Cui, Yi

2017-01-01

Solid-state lithium (Li) metal batteries are prominent among next-generation energy storage technologies due to their significantly high energy density and reduced safety risks. Previously, solid electrolytes have been intensively studied and several materials with high ionic conductivity have been identified. However, there are still at least three obstacles before making the Li metal foil-based solid-state systems viable, namely, high interfacial resistance at the Li/electrolyte interface, low areal capacity, and poor power output. The problems are addressed by incorporating a flowable interfacial layer and three-dimensional Li into the system. The flowable interfacial layer can accommodate the interfacial fluctuation and guarantee excellent adhesion at all time, whereas the three-dimensional Li significantly reduces the interfacial fluctuation from the whole electrode level (tens of micrometers) to local scale (submicrometer) and also decreases the effective current density for high-capacity and high-power operations. As a consequence, both symmetric and full-cell configurations can achieve greatly improved electrochemical performances in comparison to the conventional Li foil, which are among the best reported values in the literature. Noticeably, solid-state full cells paired with high–mass loading LiFePO4 exhibited, at 80°C, a satisfactory specific capacity even at a rate of 5 C (110 mA·hour g−1) and a capacity retention of 93.6% after 300 cycles at a current density of 3 mA cm−2 using a composite solid electrolyte middle layer. In addition, when a ceramic electrolyte middle layer was adopted, stable cycling with greatly improved capacity could even be realized at room temperature. PMID:29062894

Effect of colloidal silica on rheological properties of common pharmaceutical excipients.

PubMed

Majerová, Diana; Kulaviak, Lukáš; Růžička, Marek; Štěpánek, František; Zámostný, Petr

2016-09-01

In pharmaceutical industry, the use of lubricants is mostly based on historical experiences or trial and error methods even these days. It may be demanding in terms of the material consumption and may result in sub-optimal drug composition. Powder rheology enables more accurate monitoring of the flow properties and because the measurements need only a small sample it is perfectly suitable for the rare or expensive substances. In this work, rheological properties of four common excipients (pregelatinized maize starch, microcrystalline cellulose, croscarmellose sodium and magnesium stearate) were studied by the FT4 Powder Rheometer, which was used for measuring the compressibility index by a piston and flow properties of the powders by a rotational shear cell. After an initial set of measurements, two excipients (pregelatinized maize starch and microcrystalline cellulose) were chosen and mixed, in varying amounts, with anhydrous colloidal silicon dioxide (Aerosil 200) used as a glidant. The bulk (conditioned and compressed densities, compressibility index), dynamic (basic flowability energy) and shear (friction coefficient, flow factor) properties were determined to find an optimum ratio of the glidant. Simultaneously, the particle size data were obtained using a low-angle laser light scattering (LALLS) system and scanning electron microscopy was performed in order to examine the relationship between the rheological properties and the inner structure of the materials. The optimum of flowability for the mixture composition was found, to correspond to empirical findings known from general literature. In addition the mechanism of colloidal silicone dioxide action to improve flowability was suggested and the hypothesis was confirmed by independent test. New findings represent a progress towards future application of determining the optimum concentration of glidant from the basic characteristics of the powder in the pharmaceutical research and development. Copyright © 2016 Elsevier B.V. All rights reserved.

Production of extended release mini-tablets using directly compressible grades of HPMC.

PubMed

Mohamed, Faiezah A A; Roberts, Matthew; Seton, Linda; Ford, James L; Levina, Marina; Rajabi-Siahboomi, Ali R

2013-11-01

Hypromellose (HPMC) has been previously used to control drug release from mini-tablets. However, owing to poor flow, production of mini-tablets containing high HPMC levels is challenging. Directly compressible (DC) HPMC grades have been developed by Dow Chemical Company. To compare the properties of HPMC DC (METHOCEL™ K4M and K100M) with regular (REG) HPMC grades. Particle size distribution and flowability of HPMC REG and DC were evaluated. 3 mm mini-tablets, containing hydrocortisone or theophylline as model drugs and 40% w/w HPMC DC or REG were produced. Mini-tablets containing HPMC DC grades were manufactured using a rotary press simulator at forces between 2-4 kN and speeds of 5, 10, 15 or 20 rpm. Mini-tablets containing HPMC REG were produced manually. The improved flowability of HPMC DC grades, which have a narrower particle size distribution and larger particle sizes, meant that simulated large scale production of mini-tablets with good weight uniformity (CV 1.79-4.65%) was feasible. It was not possible to automatically manufacture mini-tablets containing HPMC REG due to the poor flowability of the formulations. Drug release from mini-tablets comprising HPMC DC and REG were comparable. Mini-tablets containing HPMC DC illustrated a higher tensile strength compared to mini-tablets made with HPMC REG. Mini-tablets produced with HPMC DC at different compression speeds had similar drug release profiles. Production of extended release mini-tablets was successfully achieved when HPMC DC was used. Drug release rate was not influenced by the different HPMC DC grades (K4M or K100M) or production speed.

Usefulness of a rotation-revolution mixer for mixing powder-liquid reline material.

PubMed

Yamaga, Yoshio; Kanatani, Mitsugu; Nomura, Shuichi

2015-01-01

The purpose of this study was to evaluate the distribution of bubbles, degree of mixing, flowability and mechanical strength of powder-liquid reline material by manually and with a rotation-revolution (planetary) mixer, and to determine the usefulness of a rotation-revolution mixer for this application. Powder-liquid reline material (Mild Rebaron, GC, Tokyo, Japan) was mixed with a powder to liquid ratio of 1:0.62 according to the manufacturer's instruction. Two methods were used to mix it: mixed by manually ("manual-mixing") and automatically with a rotation-revolution mixer (Super Rakuneru Fine, GC, Tokyo, Japan; "automatic-mixing"). Disc-shaped specimens, 30 mm in diameter and 1.0mm in thickness, were used to observe the distribution of bubbles in at 10× magnifications. Flowability tests were carried out according to the JIS T6521 for denture base hard reline materials. A three point bending test was carried out by a universal testing machine. Elastic modulus and flexural stress at the proportional limit were calculated. A median of 4 bubbles and inhomogeneous were observed in manual-mixed specimens. However, no bubbles and homogeneous were observed in automatic-mixed specimens. Flowability was within the JIS range in all mixing conditions and did not differ significantly across conditions. The elastic modulus was the same for manual-mixed and automatic-mixed specimens. On the other hand, the flexural stress at the proportional limit differed significantly between manual-mixed and automatic-mixed specimens. The results confirm that rotation-revolution mixer is useful for mixing powder-liquid reline material. Automatic-mixing may be recommended for clinical practice. Copyright © 2014 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Colour stability and opacity of resin cements and flowable composites for ceramic veneer luting after accelerated ageing.

PubMed

Archegas, Lucí Regina Panka; Freire, Andrea; Vieira, Sergio; Caldas, Danilo Biazzetto de Menezes; Souza, Evelise Machado

2011-11-01

Colour changes of the luting material can become clinically visible affecting the aesthetic appearance of thin ceramic laminates. The aim of this in vitro study was to evaluate the colour stability and opacity of light- and dual-cured resin cements and flowable composites after accelerated ageing. The luting agents were bonded (0.2 mm thick) to ceramic disks (0.75 mm thick) built with the pressed-ceramic IPS Aesthetic Empress (n=7). Colour measurements were determined using a FTIR spectrophotometer before and after accelerated ageing in a weathering machine with a total energy of 150 kJ. Changes in colour (ΔE) and opacity (ΔO) were obtained using the CIE L*a*b* system. The results were submitted to one-way ANOVA, Tukey HSD test and Student's t test (α=5%). All the materials showed significant changes in colour and opacity. The ΔE of the materials ranged from 0.41 to 2.40. The highest colour changes were attributed to RelyX ARC and AllCem, whilst lower changes were found in Variolink Veneer, Tetric Flow and Filtek Z350 Flow. The opacity of the materials ranged from -0.01 to 1.16 and its variation was not significant only for Opallis Flow and RelyX ARC. The accelerated ageing led to colour changes in all the evaluated materials, although they were considered clinically acceptable (ΔE<3). Amongst the dual-cured resin cements, Variolink II demonstrated the highest colour stability. All the flowable composites showed proper colour stability for the luting of ceramic veneers. After ageing, an increase in opacity was observed for most of the materials. Copyright © 2011 Elsevier Ltd. All rights reserved.

Principles of appendage design in robots and animals determining terradynamic performance on flowable ground.

PubMed

Qian, Feifei; Zhang, Tingnan; Korff, Wyatt; Umbanhowar, Paul B; Full, Robert J; Goldman, Daniel I

2015-10-08

Natural substrates like sand, soil, leaf litter and snow vary widely in penetration resistance. To search for principles of appendage design in robots and animals that permit high performance on such flowable ground, we developed a ground control technique by which the penetration resistance of a dry granular substrate could be widely and rapidly varied. The approach was embodied in a device consisting of an air fluidized bed trackway in which a gentle upward flow of air through the granular material resulted in a decreased penetration resistance. As the volumetric air flow, Q, increased to the fluidization transition, the penetration resistance decreased to zero. Using a bio-inspired hexapedal robot as a physical model, we systematically studied how locomotor performance (average forward speed, v(x)) varied with ground penetration resistance and robot leg frequency. Average robot speed decreased with increasing Q, and decreased more rapidly for increasing leg frequency, ω. A universal scaling model revealed that the leg penetration ratio (foot pressure relative to penetration force per unit area per depth and leg length) determined v(x) for all ground penetration resistances and robot leg frequencies. To extend our result to include continuous variation of locomotor foot pressure, we used a resistive force theory based terradynamic approach to perform numerical simulations. The terradynamic model successfully predicted locomotor performance for low resistance granular states. Despite variation in morphology and gait, the performance of running lizards, geckos and crabs on flowable ground was also influenced by the leg penetration ratio. In summary, appendage designs which reduce foot pressure can passively maintain minimal leg penetration ratio as the ground weakens, and consequently permits maintenance of effective locomotion over a range of terradynamically challenging surfaces.

Roller compaction of moist pharmaceutical powders.

PubMed

Wu, C-Y; Hung, W-L; Miguélez-Morán, A M; Gururajan, B; Seville, J P K

2010-05-31

The compression behaviour of powders during roller compaction is dominated by a number of factors, such as process conditions (roll speed, roll gap, feeding mechanisms and feeding speed) and powder properties (particle size, shape, moisture content). The moisture content affects the powder properties, such as the flowability and cohesion, but it is not clear how the moisture content will influence the powder compression behaviour during roller compaction. In this study, the effect of moisture contents on roller compaction behaviour of microcrystalline cellulose (MCC, Avicel PH102) was investigated experimentally. MCC samples of different moisture contents were prepared by mixing as-received MCC powder with different amount of water that was sprayed onto the powder bed being agitated in a rotary mixer. The flowability of these samples were evaluated in terms of the poured angle of repose and flow functions. The moist powders were then compacted using the instrumented roller compactor developed at the University of Birmingham. The flow and compression behaviour during roller compaction and the properties of produced ribbons were examined. It has been found that, as the moisture content increases, the flowability of moist MCC powders decreases and the powder becomes more cohesive. As a consequence of non-uniform flow of powder into the compaction zone induced by the friction between powder and side cheek plates, all produced ribbons have a higher density in the middle and lower densities at the edges. For the ribbons made of powders with high moisture contents, different hydration states across the ribbon width were also identified from SEM images. Moreover, it was interesting to find that these ribbons were split into two halves. This is attributed to the reduction in the mechanical strength of moist powder compacts with high moisture contents produced at high compression pressures. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Transforming from planar to three-dimensional lithium with flowable interphase for solid lithium metal batteries

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

Liu, Yayuan; Lin, Dingchang; Jin, Yang

Solid-state lithium (Li) metal batteries are prominent among next-generation energy storage technologies due to their significantly high energy density and reduced safety risks. Previously, solid electrolytes have been intensively studied and several materials with high ionic conductivity have been identified. However, there are still at least three obstacles before making the Li metal foil-based solid-state systems viable, namely, high interfacial resistance at the Li/electrolyte interface, low areal capacity, and poor power output. The problems are addressed by incorporating a flowable interfacial layer and three-dimensional Li into the system. The flowable interfacial layer can accommodate the interfacial fluctuation and guarantee excellentmore » adhesion at all time, whereas the three-dimensional Li significantly reduces the interfacial fluctuation from the whole electrode level (tens of micrometers) to local scale (submicrometer) and also decreases the effective current density for high-capacity and high-power operations. As a consequence, both symmetric and full-cell configurations can achieve greatly improved electrochemical performances in comparison to the conventional Li foil, which are among the best reported values in the literature. Noticeably, solid-state full cells paired with high–mass loading LiFePO4 exhibited, at 80°C, a satisfactory specific capacity even at a rate of 5 C (110 mA·hour g -1) and a capacity retention of 93.6% after 300 cycles at a current density of 3 mA cm -2 using a composite solid electrolyte middle layer. In addition, when a ceramic electrolyte middle layer was adopted, stable cycling with greatly improved capacity could even be realized at room temperature.« less

The effect of different drinks on the color stability of different restorative materials after one month.

PubMed

Tekçe, Neslihan; Tuncer, Safa; Demirci, Mustafa; Serim, Merve Efe; Baydemir, Canan

2015-11-01

The aim of this study was to evaluate the effect of three different drinks on the color parameters of four different restorative materials. Three different composites (Filtek Ultimate Universal Restorative, Filtek Ultimate Flowable, and Filtek Silorane, 3M ESPE) and a polyacid-modified composite resin material (Dyract XP, Dentsply DeTrey GmbH) were evaluated. Eighty-four disc-shaped specimens of 8 mm in diameter and 2 mm in thickness were prepared (n = 21 each). Color coordinates (L*a*b*, ΔL*, Δa*, Δb*, and ΔE*) were measured using a VİTA Easyshade Compact (VİTA Zahnfabrik) after 24 hr of storage (baseline) and after 30 day of storage in three different beverages of black tea, Coca cola, or water (control) (n = 7). In each beverage, the specimens were stored three times a day, one hr each, for 30 day. The color changes (ΔE) were calculated and were analyzed by Kruskal-Wallis and Dunn multiple comparison test. The color difference (ΔE*) of the resin materials ranged between 1.31 and 15.28 after 30 day of immersion in the staining solutions. Dyract XP in Coca cola (15.28 ± 2.61) and black tea (12.22 ± 2.73) showed the highest mean ΔE* value after 30 day, followed by Filtek Ultimate Universal Restorative (5.99 ± 1.25) and Filtek Ultimate Flowable (4.71 ± 1.40) in black tea (p < 0.05). The compomers displayed unacceptable color changes at the end of 30 day in all beverages. Among resin composites, the silorane based composite exhibited relatively good color stability than the others. Filtek Ultimate Universal Restorative and Filtek Flowable showed similar color changes in all beverages.

Fractography of interface after microtensile bond strength test using swept-source optical coherence tomography.

PubMed

Dao Luong, Minh Nguyet; Shimada, Yasushi; Turkistani, Alaa; Tagami, Junji; Sumi, Yasunori; Sadr, Alireza

2016-07-01

To determine the effect of crosshead speed and placement technique on interfacial crack formation in microtensile bond strength (MTBS) test using swept-source optical coherence tomography (SS-OCT). MTBS test beams (0.9×0.9mm(2)) were prepared from flat human dentin disks bonded with self-etch adhesive (Clearfil SE Bond, Kuraray) and universal composite (Clearfil AP-X, Kuraray) with or without flowable composite lining (Estelite Flow Quick, Tokuyama). Each beam was scanned under SS-OCT (Santec, Japan) at 1319nm center wavelength before MTBS test was performed at crosshead speed of either 1 or 10mm/min (n=10). The beams were scanned by SS-OCT again to detect and measure cracks at the debonded interface using digital image analysis software. Representative beams were observed under confocal laser scanning microscope to confirm the fractography findings. Two-way ANOVA showed that for MTBS the crosshead speed was not a significant factor (p>0.05), while there was a difference between placement techniques (p<0.001), with flowable lining yielding higher mean values. On the other hand, for crack formation, there was a significant difference between crosshead speeds (p<0.01), while the placement technique did not show up as a statistically significant factor (p>0.05). The interaction of factors were not significant (p>0.05). Testing MTBS samples at higher crosshead speeds induced more cracks in dentin. Lining with a flowable composite improved the bonding quality and increased the bond strength. SS-OCT can visualize interfacial cracks after restoration debonding. Copyright © 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Transforming from planar to three-dimensional lithium with flowable interphase for solid lithium metal batteries

DOE PAGES

Liu, Yayuan; Lin, Dingchang; Jin, Yang; ...

2017-10-01

Solid-state lithium (Li) metal batteries are prominent among next-generation energy storage technologies due to their significantly high energy density and reduced safety risks. Previously, solid electrolytes have been intensively studied and several materials with high ionic conductivity have been identified. However, there are still at least three obstacles before making the Li metal foil-based solid-state systems viable, namely, high interfacial resistance at the Li/electrolyte interface, low areal capacity, and poor power output. The problems are addressed by incorporating a flowable interfacial layer and three-dimensional Li into the system. The flowable interfacial layer can accommodate the interfacial fluctuation and guarantee excellentmore » adhesion at all time, whereas the three-dimensional Li significantly reduces the interfacial fluctuation from the whole electrode level (tens of micrometers) to local scale (submicrometer) and also decreases the effective current density for high-capacity and high-power operations. As a consequence, both symmetric and full-cell configurations can achieve greatly improved electrochemical performances in comparison to the conventional Li foil, which are among the best reported values in the literature. Noticeably, solid-state full cells paired with high–mass loading LiFePO4 exhibited, at 80°C, a satisfactory specific capacity even at a rate of 5 C (110 mA·hour g -1) and a capacity retention of 93.6% after 300 cycles at a current density of 3 mA cm -2 using a composite solid electrolyte middle layer. In addition, when a ceramic electrolyte middle layer was adopted, stable cycling with greatly improved capacity could even be realized at room temperature.« less

Comparative evaluation of microleakage in Class II restorations using open vs. closed centripetal build-up techniques with different lining materials

PubMed Central

Sawani, Shefali; Arora, Vipin; Jaiswal, Shikha; Nikhil, Vineeta

2014-01-01

Background: Evaluation of microleakage is important for assessing the success of new restorative materials and methods. Aim and Objectives: Comparative evaluation of microleakage in Class II restorations using open vs. closed centripetal build-up techniques with different lining materials. Materials and Methods: Standardized mesi-occlusal (MO) and distoocclusal (DO) Class II tooth preparations were preparedon 53 molars and samples were randomly divided into six experimental groups and one control group for restorations. Group 1: Open-Sandwich technique (OST) with flowable composite at the gingival seat. Group 2: OST with resin-modified glass ionomer cement (RMGIC) at the gingival seat. Group 3: Closed-Sandwich technique (CST) with flowable composite at the pulpal floor and axial wall. Group 4: CST with RMGIC at the pulpal floor and axial wall. Group 5: OST with flowable composite at the pulpal floor, axial wall, and gingival seat. Group 6: OST with RMGIC at the pulpal floor, axial wall, and gingival seat. Group 7: Control — no lining material, centripetal technique only. After restorations and thermocycling, apices were sealed and samples were immersed in 0.5% basic fuchsin dye. Sectioning was followed by stereomicroscopic evaluation. Results: Results were analyzed using Post Hoc Bonferroni test (statistics is not a form of tabulation). Cervical scores of control were more than the exprimental groups (P < 0.05). Less microleakage was observed in CST than OST in all experimental groups (P < 0.05). However, insignificant differences were observed among occlusal scores of different groups (P > 0.05). Conclusion: Class II composite restorations with centripetal build-up alone or when placed with CST reduces the cervical microleakage when compared to OST. PMID:25125847

Effect of bulk-fill base material on fracture strength of root-filled teeth restored with laminate resin composite restorations.

PubMed

Taha, N A; Maghaireh, G A; Ghannam, A S; Palamara, J E

2017-08-01

To evaluate the effect of using a bulk-fill flowable base material on fracture strength and fracture patterns of root-filled maxillary premolars with MOD preparations restored with laminate restorations. Fifty extracted maxillary premolars were selected for the study. Standardized MOD cavities with endodontic treatment were prepared for all teeth, except for intact control. The teeth were divided randomly into five groups (n=10); (Group 1) sound teeth, (Group 2) unrestored teeth; (Group 3) MOD cavities with Vitrebond base and resin-based composite (Ceram. X One Universal); (Group 4) MOD cavities with 2mm GIC base (Fuji IX GP) and resin-based composite (Ceram. X One Universal) open laminate, (Group 5) MOD cavities were restored with 4mm of bulk-fill flowable base material (SDR) and resin-based composite (Ceram. X One Universal). All teeth were thermocycled and subjected to a 45° ramped oblique load in a universal testing machine. Fracture load and fracture patterns were recorded. Data were analyzed using one-way ANOVA and Dunnett's T3 test. Restoration in general increased the fracture strength compared to unrestored teeth. The fracture strength of group 5 (bulk-fill) was significantly higher than the fracture strength of the GIC laminate groups and not significantly different from the intact teeth (355±112N, P=0.118). The type of failure was unfavorable for most of the groups, with the majority being mixed failures. The use of a bulk-fill flowable base material significantly increased the fracture strength of extracted root-filled teeth with MOD cavities; however it did not improve fracture patterns to more favorable ones. Investigating restorative techniques that may improve the longevity of root-filled premolar teeth restored with direct resin restorations. Copyright © 2017 Elsevier Ltd. All rights reserved.

Setting time and flowability of accelerated Portland cement mixed with polycarboxylate superplasticizer.

PubMed

Wongkornchaowalit, Norachai; Lertchirakarn, Veera

2011-03-01

Important limitations of mineral trioxide aggregate for use in clinical procedures are extended setting time and difficult handling characteristics. The removal of gypsum at the end stage of the Portland cement manufacturing process and polycarboxylate superplasticizer admixture may solve these limitations. Different concentrations of polycarboxylate superplasticizer (0%, 1.2%, 1.8%, and 2.4% by volume) and liquid-to-powder ratios (0.27, 0.30, and 0.33 by weight) were mixed with white Portland cement without gypsum (AWPC-experimental material). Type 1 ordinary white Portland cement mixed with distilled water at the same ratios as the experimental material was used as controls. All samples were tested for setting time and flowability according to the International Organization for Standardization 6876:2001 guideline. The data were analyzed by two-way analysis of variance. Then, one-way analysis of variance and multiple comparison tests were used to analyze the significance among groups. The data are presented in mean ± standard deviation values. In all experimental groups, the setting times were in the range of 4.2 ± 0.4 to 11.3 ± 0.2 minutes, which were significantly (p < 0.05) lower than the control groups (26.0 ± 2.4 to 54.8 ± 2.5 minutes). The mean flows of AWPC plus 1.8% and 2.4% polycarboxylate superplasticizer groups were significantly increased (p < 0.001) at all liquid-to-powder ratios compared with control groups. Polycarboxylate superplasticizer at concentrations of 1.8% and 2.4% and the experimental liquid-to-powder ratios reduced setting time and increased flowability of cement, which would be beneficial for clinical use. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Rheological and Mechanical Response Modifications for a Self-Leveling Mortar

NASA Astrophysics Data System (ADS)

Katsiadramis, N. J.; Sotiropoulou, A. B.; Pandermarakis, Z. G.

2010-06-01

In many cases cement based materials demand a higher flowability and workability and this conventionally can’t be done without loss of its strength, due to the fact that the common practice to increase the workability is the addition of water. But, nowadays using a third generation superplasticizer (SP) we can achieve the desire flowability without loss of its strength. The action of superplastisizers is to spread efficiently the cement grains and so to wetting better the cement grains giving a more homogeneous mixture with higher strength. Nine different mixtures were prepared adding a small percentage of SP (1%). The conditions to get a self levelling mortar, have to do not only with rheological but also with mechanical demands. The bending and compression test gave the achieving mechanical strength whereas their rheological response came through slump flow and v-funnel flow tests. With the help of a small amount of stabilizer we obtain a robust mixture that deserves the desire response at the field too.

Effect of moisture content on the flowability of crushed ores

NASA Astrophysics Data System (ADS)

Cabrejos, Francisco

2017-06-01

In many mining and industrial processes where large quantities of non-degrading bulk materials such as crushed ores are handled, silos, hoppers, stockpiles and chutes are widely used because they are economical and reliable (if properly designed and operated). However, they are not free of trouble and may experience flow problems such as arching, ratholing, erratic flow, limited storage capacity, limited discharge flow rate, caking, segregation and/or flooding. Moisture content and fine particles significantly affect the flowability of most ores, increasing their cohesive strength and turning them more prone to these problems. The purpose of this article is to highlight a proven, scientific method that can be utilized to ensure reliable storage, flow and discharge of bulk solids in these equipment based on Jenike's flow-of-solids theory and laboratory testing. Knowledge of the flow properties of the material handled provides a design basis to ensure mass flow, avoid arching and prevent the formation of "ratholes". The effect of an increase in water content of the ore is discussed with experimental results.

Modification of flow and compressibility of corn starch using quasi-emulsion solvent diffusion method.

PubMed

Akhgari, Abbas; Sadeghi, Hasti; Dabbagh, Mohammad Ali

2014-08-01

The aim of this study was to improve flowability and compressibility characteristics of starch to use as a suitable excipient in direct compression tabletting. Quasi-emulsion solvent diffusion was used as a crystal modification method. Corn starch was dissolved in hydrochloric acid at 80°C and then ethanol as a non-solvent was added with lowering temperature until the formation of a precipitate of modified starch. Flow parameters, particle size and thermal behavior of the treated powders were compared with the native starch. Finally, the 1:1 mixture of naproxen and each excipient was tabletted, and hardness and friability of different tablets were evaluated. Larger and well shaped agglomerates were formed which showed different thermal behavior. Treated starch exhibited suitable flow properties and tablets made by the treated powder had relatively high hardness. It was found that recrystallization of corn starch by quasi emulsion solvent diffusion method could improve its flowability and compressibility characteristics.

Multi-species mating disruption in cranberries (Ericales: Ericaceae): Early evidence using a flowable emulsion

USDA-ARS?s Scientific Manuscript database

Pheromone-based mating disruption has proven to be a powerful pest management tool in many cropping systems, helping to reduce reliance on insecticide applications. However, a sustainable mating disruption program has not yet been developed for cranberries. In the cranberry system, two of the major ...

U.S. EPA, Pesticide Product Label, DACONIL ZN FLOWABLE FUNGICIDE, 02/20/2007

EPA Pesticide Factsheets

2011-04-21

... " .... chemi¢aI··r~sistalic~(c~te.gQrY.: s~l~ctipn':cti~·rt) : ~h;~~:j~:.~i:t~~~igv~;~~ a~;~f.'~m'.V!~~~iRrd(;(rnate~ai ~I Revised. • shoes plus socks ...

78 FR 72881 - Notice of Receipt of Requests to Voluntarily Cancel Certain Pesticide Registrations

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-04

...; the chemical industry; pesticide users; and members of the public interested in the sale, distribution... Flowable ene & Carboxin. Fungicide. 000264-00943 RTU-Vitavax-Thiram Thiram & Carboxin. Seed Protectant... subtilis GB03 & Metalaxyl. 000264-00958 Tops MZ Potato Seed- Mancozeb & Piece Treatment Thiophanate-methyl...

Cottonwood leaf beetle control with imidacloprid soaked cuttings

Treesearch

Terry L. Robinson; Randall J. Rousseau

2007-01-01

Dormant, unrooted cuttings from three eastern cottonwood (Populus deltoides Marsh.) clones were soaked in either water or one of two concentrations of Admire® 2 Flowable (imidacloprid) insecticide. Half were planted immediately after soaking while the other half were stored for 12 weeks at -2℃ prior to planting. Trees from...

U.S. EPA, Pesticide Product Label, CUTLASS AQUEOUS FLOWABLE BIOINSECTICIDE, 04/21/1994

EPA Pesticide Factsheets

2011-04-21

... _ of P .. tlclde Product ... West Langhorne, PA 19047-1810 • ·~~'ti;g" •.. 1a~1";¥tfU1119 111 .• w.taiocoI.#~Mt~;,IiYi!k!;i,!~~. Vi~~~l.fi~H~:~~ ; ...

Boundary Layer Transition During the Orion Exploration Flight Test 1 (EFT-1)

NASA Technical Reports Server (NTRS)

Kirk, Lindsay C.

2016-01-01

Boundary layer transition was observed in the thermocouple data on the windside backshell of the Orion reentry capsule. Sensors along the windside centerline, as well as off-centerline, indicated transition late in the flight at approximately Mach 4 conditions. Transition progressed as expected, beginning at the sensors closest to the forward bay cover (FBC) and moving towards the heatshield. Sensors placed in off-centerline locations did not follow streamlines, so the progression of transition observed in these sensors is less intuitive. Future analysis will include comparisons to pre-flight predictions and expected transitional behavior will be investigated. Sensors located within the centerline and off-centerline launch abort system (LAS) attach well cavities on the FBC also showed indications of boundary layer transition. The transition within the centerline cavity was observed in the temperature traces prior to transition onset on the sensors upstream of the cavity. Transition behavior within the off centerline LAS attach well cavity will also be investigated. Heatshield thermocouples were placed within Avcoat plugs to attempt to capture transitional behavior as well as better understand the aerothermal environments. Thermocouples were placed in stacks of two or five vertically within the plugs, but the temperature data obtained at the sensors closest to the surface did not immediately indicate transitional behavior. Efforts to use the in depth thermocouple temperatures to reconstruct the surface heat flux are ongoing and any results showing the onset of boundary layer transition obtained from those reconstructions will also be included in this paper. Transition on additional features of interest, including compression pad ramps, will be included if it becomes available.

Assessing Face Validity of a Food Behavior Checklist for Limited-resource Filipinos

PubMed Central

Buchthal, Opal Vanessa; Tauyan, Socorro

2015-01-01

Abstract Diet-related chronic health conditions are prevalent in the Filipino American community; however, there is a lack of rigorously validated nutrition education evaluation tools in Tagalog for use in this population. This study aimed to develop and evaluate the face validity of a Tagalog-language food behavior checklist (FBC). A multi-step method was used, involving translation of questionnaire text from English to Tagalog by a team of professionals, creation of accompanying color photographs, cognitive testing with the target population, final review by the team of professionals, and assessment of readability. Subjects for cognitive testing were men (n=6) and women (n=14) 18 years or older in Hawai‘i who received or were eligible to receive Supplemental Nutrition Assistance Program (SNAP) benefits, self-identified as Filipino, and preferred Tagalog rather than English. Participants were recruited from churches, the Filipino Center, and other community sites. Cognitive interviews revealed several issues with text and photographs, such as preferences for specific terms, and images that did not adequately illustrate the text. Image changes were made to reflect items most commonly consumed. The team of professionals agreed with participant suggestions. Assessment of readability revealed a reading level appropriate for a low-literacy population of grade 5.9. The multi-step process, which allowed members of the target audience to reveal the appropriateness of the questionnaire, yielded a Tagalog-language FBC found to have adequate face validity. After further evaluation of validity and reliability, this tool may be used to evaluate behavior change resulting from the United States Department of Agriculture's (USDA) nutrition education programs. PMID:26535163

Refined avian risk assessment for chlorpyrifos in the United States.

PubMed

Moore, Dwayne R J; Teed, R Scott; Greer, Colleen D; Solomon, Keith R; Giesy, John P

2014-01-01

Refined risk assessments for birds exposed to flowable and granular formulations ofCPY were conducted for a range of current use patterns in the United States. Overall,the collective evidence from the modeling and field study lines of evidence indicate that flowable and granular CPY do not pose significant risks to the bird communities foraging in agro-ecosystems in the United States. The available information indicates that avian incidents resulting from the legal, registered uses of CPY have been very infrequent since 2002 (see SI Appendix 3). The small number of recent incidents suggests that the current labels for CPY are generally protective of birds.However, incident data are uncertain because of the difficulties associated with finding dead birds in the field and linking any mortality observed to CPY.Plowable CPY is registered for a variety of crops in the United States including alfalfa, brassica vegetables, citrus, corn, cotton, grape, mint, onion, peanut, pome and stone fruits, soybean, sugar beet, sunflower, sweet potato, tree nuts, and wheat under the trade name Lorsban Advanced. The major routes of exposure for birds to flowable CPY were consumption of treated dietary items and drinking water. The Liquid Pesticide Avian Risk Assessment Model (Liquid PARAM) was used to simulate avian ingestion of CPY by these routes of exposure. For acute exposure,Liquid PARAM estimated the maximum retained dose in each of 20 birds on each of1,000 fields that were treated with CPY over the 60-d period following initial application.The model used a 1-h time step. For species lacking acceptable acute oral toxicity data (all focal species except northern bobwhite (C. virginianus) and redwinged blackbird (A. phoeniceus)), a species sensitivity distribution (SSD) approach was used to generate hypothetical dose-response curves assuming high, median and low sensitivity to CPY. For acute risk, risk curves were generated for each use pattern and exposure scenario. The risk curves show the relationship between exceedence probability and percent mortality. The results of the Liquid PARAM modeling exercise indicate that flow able CPY poses an acute risk to some bird species, particularly those species that are highly sensitive and that forage extensively in crops with high maximum application rates (e.g., grapefruit, orange). Overall, most bird species would not experience significant mortality as a result of exposure to flowable CPY.The results of a number of field studies conducted at application rates comparable to those on the Lorsban Advanced label indicate that flowable CPY rarely causes avian mortality. The results of the field studies suggest that Liquid PARAM is likely over-estimating acute risk to birds for flowable CPY.For chronic exposure, Liquid PARAM estimated the maximum total daily intake (TDI) over a user-specified exposure duration (28-d in the case of CPY).The maximum average TDI was compared to the chronic NOEL and LOEL from the most sensitive species tested for CPY, the mallard. This comparison was done for each of the 20 birds in each of the 1000 fields simulated in Liquid PARAM.The outpu· ~ are estimates of the probabilities of exceeding the NOEL and LOEL.Liquid PAkAM did not predict significant adverse effects resulting from chronic exposure to flowable CPY. The small number of incidents (2) involving CPY reported since 2002 suggests that the current labels for CPY are generally protective of birds.Granular CPY is registered for a wide variety of crops including brassica vegetables, corn, onion, peanut, sugar beet, sunflower, and tobacco under the trade name Lorsban 15G. Consumption of grit is required by many birds to aid in digestion of hard dietary items such as seeds and insects. Because CPY granules are in the same size range as natural grit particles consumed by birds, there is a potential for birds to mistakenly ingest granular CPY instead of natural grit. We developed the Granular Pesticide Avian Risk Model (GranPARAM) to simulate grit ingestion behavior by birds. The model accounts for proportion of time that birds forage for grit in treated fields, relative proportions of natural grit versus pesticide granules onthe surface of treated fields, rates of ingestion of grit, attractiveness of pesticide granules relative to natural grit and so on. For CPY, each model simulation included20 birds on each of 1,000 fields to capture variability in rates of ingestion of grit and for aging behavior between birds within a focal species, and variability in soil composition between fields for the selected use pattern. The estimated dose for each birdwas compared with randomly chosen doses from relevant dose-response curves forCPY. Our analysis for a wide variety of use patterns on the Lorsban 15G label found that granular CPY poses little risk of causing mortality to bird species that frequent treated fields immediately after application. The predictions of the model have been confirmed in several avian field studies conducted with Lorsban 15G at application rates similar to or exceeding maximum application rates on the Lorsban 15G label.

Injection of coal combustion byproducts into the Omega Mine for the reduction of acid mine drainage

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

Gray, T.A.; Moran, T.C.; Broschart, D.W.

1998-12-31

The Omega Mine Complex is located outside of Morgantown, West Virginia. The mine is in the Upper Freeport Coal, an acid-producing coal seam. The coal was mined in a manner that has resulted in acid mine drainage (AMD) discharges at multiple points. During the 1990`s, the West Virginia Division of Environmental Protection (WVDEP) assumed responsibility for operating a collection and treatment system for the AMD. Collection and treatment costs are approximately $300,000 per year. An innovative procedure of injecting grout into the mine workings to reduce AMD and the resulting treatment costs is proposed. The procedure involves injecting grout mixesmore » composed primarily of coal combustion byproducts (CCB`s) and water, with a small quantity of cement. The intention of the injection program is to fill the mine voids in the north lobe of the Omega Mine (an area where most of the acidity is believed to be generated) with the grout, thus reducing the contact of air and water with potentially acidic material. The grout mix design consists of an approximate 1:1 ratio of fly ash to byproducts from fluidized bed combustion. Approximately 100 gallons of water per cubic yard of grout is used to help achieve flowability. Observation of the mine workings via subsurface borings and downhole video camera operation confirmed that first-mined areas were generally open while second-mined areas were generally partially collapsed. Closer injection hole spacing was used in second-mined areas to account for collapsed workings. The construction documents have been prepared with the project being bid in late 1997. The engineer`s cost estimate was approximately $2,500,000, with the low bid of approximately $2,300,000 being submitted by Howard Concrete Pumping of Bridgeville, PA.« less

Characterization of the synergistic interaction between Beauveria bassiana strain GHA and Bacillus thuringiensis morrisoni strain tenebrionis applied against Colorado potato beetle

USDA-ARS?s Scientific Manuscript database

Studies were undertaken to further characterize the previously identified synergistic activity of Bacillus thuringiensis- and Beauveria bassiana-based biopesticides against Colorado potato beetle (CPB). A flowable concentrate of B. thuringiensis morrisoni strain tenebrionis (Bt) (Novodor® FC) and a ...

Effects of Varying CDS Levels and Drying and Cooling Temperatures on Flowability Properties of DDGS

USDA-ARS?s Scientific Manuscript database

Demand for alternative fuels and the need to reduce dependence on fossil fuels, have triggered the growth of corn-based ethanol production, and this is expected to rise in future years. Transportation of the co-product distillers dried grains with solubles (DDGS) from this industry occurs under vari...

Alleviating Concrete Placement Issues Due to Congestion of Reinforcement in Post-Tensioned Haunch Slab Bridges - Phase 1

DOT National Transportation Integrated Search

2012-07-01

A flowable hybrid concrete mix with a spread of 17 to 20 inches was created with a superplasticizer to be used in post-tension haunch-slab (PTHS) bridges where rebar congestion is heaviest. The mix would allow for proper concrete consolidation. A con...

Novel Approaches in Formulation of Entomopathogenic Fungi for Control of Insects in Soil, Foliar, and Structural Habitats: Thinking Outside the Box and Expecting the Unexpected

USDA-ARS?s Scientific Manuscript database

By and large, mycoinsecticide formulations have involved sprayable products, typically oil flowables, emulsifiable suspensions, wettable powders, and water dispersable granules. Various nutritive or inert carriers have been used to create granular formulations for use against soil pests. Sometime...

Effects of rheology and viscosity of biobased adhesives on bonding performance

USDA-ARS?s Scientific Manuscript database

Rheology is the science of deformation and flow of the matter due to the application of a force. Most rheological tests involve applying a force to a material and measuring its flow or change in shape. Rheological characterization is useful to study the flowability and viscoelastic properties of adh...

Process for improving soluble coal yield in a coal deashing process

DOEpatents

Rhodes, Donald E.

1980-01-01

Coal liquefaction products are contacted with a deashing solvent and introduced into a first separation zone. The first separation zone is maintained at an elevated temperature and pressure, determined to maximize the recovery of soluble coal products, to cause said coal liquefaction products to separate into a first light phase and a first heavy phase. Under these conditions the heavy phase while still fluid-like in character is substantially non-flowable. Flowability is returned to the fluid-like heavy phase by the introduction of an additional quantity of deashing solvent into the first separation zone at a location below the interface between the first light and heavy phases or into the heavy phase withdrawal conduit during withdrawal of the first heavy phase and prior to any substantial pressure reduction. The first heavy phase then is withdrawn from the first separation zone for additional downstream processing without plugging either the withdrawal conduit or the downstream apparatus. The first light phase comprising the soluble coal products is withdrawn and recovered in an increased yield to provide a more economical coal deashing process.

Influence of the processed sunflower oil on the cement properties

NASA Astrophysics Data System (ADS)

Fleysher, A. U.; Tokarchuk, V. V.; Sviderskiy, V. A.

2015-01-01

Used oils (vegetable oil, animal oil, engine oil, etc.), which are essentially industrial wastes, have found application as secondary raw materials in some braches of industry. In particular, the only well-known and commonly-used way of utilizing wastes of vegetable oils is to apply them as raw materials in the production of biodiesel. The goal of the present study is to develop a conceptually new way of vegetable oil wastes utilization in the building industry. The test admixture D-148 was obtained from the processing of wastes of sunflower oil and it mainly consists of fatty acid diethanolamide. The test admixture was added to the cement system for the purpose of studying its influence on water demand, flowability, setting times, compressive strength and moisture adsorption. The test admixture D-148 at the optimal content 0. 2 weight % causes 10% decrease in water demand, 1.7 time increase in flowability (namely spread diameter), 23% increase in grade strength and 34% decrease in moisture adsorption. The results of the present investigation make it possible to consider the final product of the waste sunflower oil processing as multifunctional plasticizing-waterproofing admixture.

Printability of calcium phosphate powders for three-dimensional printing of tissue engineering scaffolds.

PubMed

Butscher, Andre; Bohner, Marc; Roth, Christian; Ernstberger, Annika; Heuberger, Roman; Doebelin, Nicola; von Rohr, Philipp Rudolf; Müller, Ralph

2012-01-01

Three-dimensional printing (3DP) is a versatile method to produce scaffolds for tissue engineering. In 3DP the solid is created by the reaction of a liquid selectively sprayed onto a powder bed. Despite the importance of the powder properties, there has to date been a relatively poor understanding of the relation between the powder properties and the printing outcome. This article aims at improving this understanding by looking at the link between key powder parameters (particle size, flowability, roughness, wettability) and printing accuracy. These powder parameters are determined as key factors with a predictive value for the final 3DP outcome. Promising results can be expected for mean particle size in the range of 20-35 μm, compaction rate in the range of 1.3-1.4, flowability in the range of 5-7 and powder bed surface roughness of 10-25 μm. Finally, possible steps and strategies in pushing the physical limits concerning improved quality in 3DP are addressed and discussed. Copyright © 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

A mixed solvent system for preparation of spherically agglomerated crystals of ascorbic acid.

PubMed

Ren, Fuzheng; Zhou, Yaru; Liu, Yan; Fu, Jinping; Jing, Qiufang; Ren, Guobin

2017-09-01

The objective of this research was to develop a novel solvent system to prepare spherically agglomerated crystals (SAC) of ascorbic acid with improved flowability for direct compression. A spherical agglomeration method was developed by selecting the mixed solvents (n-butyl and ethyl acetate) as a poor solvent and the process was further optimized by using triangular phase diagram and particle vision measurement. Physiochemical properties of SAC were characterized and compared with original drug crystals. It showed that amount of poor solvent, ratio of solvent mixture, and drug concentration are critical for preparation of SAC with desirable properties. The solid state of SAC was same as original crystals according to DSC, XRD, and FT-IR results. There was no significant difference in solubility and dissolution rate of drug between SAC and original crystals. The flowability and packability of SAC as well as the tensile strength and elastic recovery of tablets made from SAC were all significantly improved when compared with original crystals and tablets from crystals. It is concluded that the present method was suitable to prepare SAC of ascorbic acid for direct compression.

Apparatus and method for transient thermal infrared spectrometry of flowable enclosed materials

DOEpatents

McClelland, John F.; Jones, Roger W.

1993-03-02

A method and apparatus for enabling analysis of a flowable material enclosed in a transport system having an infrared transparent wall portion. A temperature differential is transiently generated between a thin surface layer portion of the material and a lower or deeper portion of the material sufficient to alter the thermal infrared emission spectrum of the material from the black-body thermal infrared emission spectrum of the material, and the altered thermal infrared emission spectrum is detected through the infrared transparent portion of the transport system while the altered thermal infrared emission spectrum is sufficiently free of self-absorption by the material of emitted infrared radiation. The detection is effected prior to the temperature differential propagating into the lower or deeper portion of the material to an extent such that the altered thermal infrared emission spectrum is no longer sufficiently free of self-absorption by the material of emitted infrared radiation. By such detection, the detected altered thermal infrared emission spectrum is indicative of characteristics relating to molecular composition of the material.

Fossil Energy Program

NASA Astrophysics Data System (ADS)

McNeese, L. E.

1981-01-01

Increased utilization of coal and other fossil fuel alternatives as sources of clean energy is reported. The following topics are discussed: coal conversion development, chemical research and development, materials technology, component development and process evaluation studies, technical support to major liquefaction projects, process analysis and engineering evaluations, fossil energy environmental analysis, flue gas desulfurization, solid waste disposal, coal preparation waste utilization, plant control development, atmospheric fluidized bed coal combustor for cogeneration, TVA FBC demonstration plant program technical support, PFBC systems analysis, fossil fuel applications assessments, performance assurance system support for fossil energy projects, international energy technology assessment, and general equilibrium models of liquid and gaseous fuel supplies.

Stabilization of IgG1 in spray-dried powders for inhalation.

PubMed

Schüle, S; Schulz-Fademrecht, T; Garidel, P; Bechtold-Peters, K; Frieb, W

2008-08-01

The protein stabilizing capabilities of spray-dried IgG1/mannitol formulations were evaluated. The storage stability was tested at different residual moisture levels prepared by vacuum-drying or equilibration prior to storage. Vacuum-drying at 32 degrees C/0.1mbar for 24h reduced the moisture level below 1%, constituting an optimal basis for improved storage stability. The crystalline IgG1/mannitol powders with a weight ratio of 20/80 up to 40/60 failed to prevent the antibody aggregation as assessed by size exclusion chromatography during storage. Ratios of 60/40 up to 80/20 IgG1/mannitol provided superior stability of the antibody and the powders could be produced with high yields. The lower the residual moisture, the better was the stabilizing capability. An amount of 20% mannitol provided the best stabilization. Storage stability of 60/40, 70/30, and 80/20 IgG1/mannitol formulations over one year was adequate at 2-8 degrees C and 25 degrees C. Closed storage (sealed in vials) at 40 degrees C/75% RH and open storage at 25 degrees C/60% RH revealed that the stability still required optimization. The lower the protein content, the better was the powder flowability. The aerodynamic properties of powders spray-dried with 10% solids content were inadequate, as the particle size ranged between 5.1 and 7.2 microm and the fine particle fraction accounted for only 4-11%. Reduction of the solids content to 2.5% did improve the aerodynamic properties as the mass mean aerodynamic diameter was reduced to 3.6 microm and the fine particle fraction was increased to about 14%. The reduction of the solids content did not influence the storage stability significantly. Also spray-drying at higher temperatures had no significant impact on the storage stability, despite a higher tendency to form amorphous systems. In order to improve the storage stability and to maintain the good flowability of 70/30 IgG1/mannitol powder or to keep the storage stability but to improve the flowability of the 80/20 IgG1/mannitol powder, mannitol was partially substituted by a second excipient such as trehalose, sucrose, glycine, lactose, lactosucrose, or dextran 1. Differences in the stabilizing capability were noticeable upon closed storage at 40 degrees C/75% RH and open powder storage. Protein stabilization was improved by the addition of glycine but trehalose and sucrose were most effective in preventing aggregation, which can be primarily attributed to the water replacement properties of the sugars. The addition of another excipient, isoleucine had positive effects on both flowability and protein stability.

Investigation of drug-excipient compatibility using rheological and thermal tools

NASA Astrophysics Data System (ADS)

Trivedi, Maitri R.

HYPOTHESIS: We plan to investigate a different approach to evaluate drug-excipient physical compatibility using rheological and thermal tools as opposed to commonly used chemical techniques in pharmaceutical industry. This approach offers practical solutions to routinely associated problems arising with API's and commonly used hydrates forms of excipients. ABSTRACT: Drug-Excipient compatibility studies are an important aspect of pre-formulation and formulation development in pharmaceutical research and development. Various approaches have been used in pharmaceutical industry including use of thermal analysis and quantitative assessment of drug-excipient mixtures after keeping the samples under stress environment depending upon the type of formulation. In an attempt to provide better understanding of such compatibility aspect of excipients with different properties of API, various rheological and thermal studies were conducted on binary mixtures of excipients which exist in different hydrates. Dibasic Calcium Phosphate (DCP, anhydrous and dihydrate forms) and Lactose (Lac, anhydrous and monohydrate) were selected with cohesive API's (Acetaminophen and Aspirin). Binary mixtures of DCP and Lac were prepared by addition of 0% w/w to 50% w/w of the API into each powder blend. Rheological and thermal aspects were considered using different approaches such as powder rheometer, rotational shear cell and traditional rheometery approaches like angle of repose (AOR), hausner's ratio (HR) and cares index (CI). Thermal analysis was conducted using modulated differential scanning calorimetry (MDSC) and thermal effusivity. The data suggested that the powder rheometer showed distinctive understanding in the flowability behavior of binary mixtures with addition of increasing proportion of API's than traditional approaches. Thermal approaches revealed the potential interaction of water of crystallization DCP-D with the API (APAP) while such interactions were absent in DCP-A, while in case of Lac-M and Lac-A, interaction with water of crystallization were not present. Binary mixtures prepared with DCP-D were better flowable while blends with DCP-A were better in stability (physical), compressibility and permeability. Similarly binary mixtures prepared with Lac-M were better flowable and stable in physical compatibility as compared to Lac-A. Lac-A were better in compressibility and permeability. Second part of these research included understanding the powder behavior from wet granulation point of view. Wet granulation includes the formation of agglomerates with powders to form granules in order to have better flowability, content uniformity and compressibility of granular mass. End point determination of powders involving change in powder energies and compressibility, permeability along with thermal analyses were conducted. The effects of water of crystallization on end point determination was studied and based on which overall effects on drug-excipient compatibility using different hydrate forms of excipients were evaluated.

Effects of CDS and Drying Temperature Levels on the Flowability Behavior of DDGS

USDA-ARS?s Scientific Manuscript database

The fuel ethanol industry has been one of the fastest growing industries, with a growth rate of more than 300% since 2000. Due to demand for alternative fuels and the need to reduce dependence on fossil fuels, the growth of ethanol production is expected to rise in future years. One of the problems ...

Effects of Varying CDS, Drying and Cooling Temperatures on Glass Transition Temperature of DDGS

USDA-ARS?s Scientific Manuscript database

Distillers dried grains with solubles (DDGS), a co product of the corn-based fuel ethanol industry, is used widely as an animal feed. Due to increased demand for DDGS in livestock markets it has become essential to transport DDGS over long distances. Flowability problems in DDGS, due to particle cak...

U.S. EPA, Pesticide Product Label, GRANOL PLUS FLOWABLE INSECT. AND FUNG. CEREAL SEED TRT., 07/31/1992

EPA Pesticide Factsheets

2011-04-21

... ( f ••••• trat~ Itt. k _ial. De .. te .. ... Iuti.,. lII .. t st_ actsS trfttH sttds WtW ,.Iuti., Ii ... Nttt To Ustrl Sttd cII.rdilll1T trftttd wi" tkis ""Itt lISt Itt _'-t,IY dYtd iii .. ...

75 FR 61750 - Chloroneb; Product Cancellation Order for Certain Pesticide Registrations

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-06

... identified in Table 1 of Unit II. in a manner inconsistent with any of the Provisions for Disposition of... registrations are listed in sequence by registration number in Table 1 of this unit. Table 1--Chloroneb Product... Terraneb SP Turf Fungicide. 73782-4 Terraneb SP Flowable Turf and Ornamental Fungicide. Table 2 of this...

9 CFR 72.13 - Permitted dips and procedures.

Code of Federal Regulations, 2011 CFR

2011-01-01

... flowable form labeled for use as a 0.25 percent dip and used at a concentration of 0.125 to 0.250. 4 (3... Section 72.13 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF... until dry. 4 4 Care is required when treating animals and in maintaining the required concentration of...

On the Currents and Transports Connected with the Atlantic Meridional Overtuning Circulation in the Subpolar North Atlantic

DTIC Science & Technology

2013-08-14

of the main results follow in section 6. 40˚ 44˚ 48˚ 52˚ 56˚ 60˚ 64˚ 68˚ Greenland Iceland Scotland UK Ireland De nm ar k St ra it IFR FBC WTR HB...Flemish Cap/Pass HB: Hatton Bank IFR : Iceland−Faroe Ridge RC/P: Rockall Channel/Plateau WTR: Wyville−Thomson Ridge 4 3 2 1 km −60˚ −50˚ −40˚ −30˚ −20...important role in the wintertime deep convection in the Labrador Sea, which may impact the AMOC (However, Pickart and Spall [2007] suggested that the

Disruption of the leafminer Phyllocnistis citrella (Lepidoptera: Gracillariidae) in citrus: effect of blend and placement height, longevity of disruption and emission profile of a new dispenser

USDA-ARS?s Scientific Manuscript database

Recent efforts to disrupt mating of the leafminer, Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae), a global pest of citrus, have focused on the use of SPLAT™ (ISCA Technologies), a flowable wax emulsion intended to serve as a slow-release matrix for pheromones. Early success with this...

Evaluation of Flowable Fill Surface Performance

DTIC Science & Technology

2016-11-01

Army position unless so designated by other authorized documents. DESTROY THIS REPORT WHEN NO LONGER NEEDED. DO NOT RETURN IT TO THE ORIGINATOR...33 viii Preface This study was conducted for the U.S. Air Force’s (USAF) pavement evaluation teams, contingency readiness groups, base civil...engineers, major command pavement engineers, Rapid Engineer Deployable Heavy Operational Repair Squadron Engineer (RED HORSE) squadrons, and Prime Base

Influence of casting conditions on durability and structural performance of HPC-AR : optimization of self-consolidating concrete to guarantee homogeneity during casting of long structural elements : final report.

DOT National Transportation Integrated Search

2017-05-01

This report is a summary of the research done on dynamic segregation of self-consolidating concrete (SCC) including the casting of pre-stressed beams at Coreslab Structures. SCC is a highly flowable concrete that spreads into place with little to no ...

Formulation, characterization and physicochemical evaluation of potassium citrate effervescent tablets.

PubMed

Aslani, Abolfazl; Fattahi, Fatemeh

2013-01-01

The aim of this study was to design and formulation of potassium citrate effervescent tablet for reduction of calcium oxalate and urate kidney stones in patients suffering from kidney stones. In this study, 13 formulations were prepared from potassium citrate and effervescent base in different concentration. The flowability of powders and granules was studied. Then effervescent tablets were prepared by direct compression, fusion and wet granulation methods. The prepared tablets were evaluated for hardness, friability, effervescent time, pH, content uniformity. To amend taste of formulations, different flavoring agents were used and then panel test was done by using Latin Square method by 30 volunteers. Formulations obtained from direct compression and fusion methods had good flow but low hardness. Wet granulation improves flowability and other physicochemical properties such as acceptable hardness, effervescence time ≤3 minutes, pH<6, friability < 1%, water percentage < 0.5% and accurate content uniformity. In panel test, both of combination flavors; (orange - lemon) and (strawberry - raspberry) had good acceptability. The prepared tablets by wet granulation method using PVP solution had more tablet hardness. It is a reproducible process and suitable to produce granules that are compressed into effervescent tablets due to larger agglomerates.

Formulation, Characterization and Physicochemical Evaluation of Potassium Citrate Effervescent Tablets

PubMed Central

Aslani, Abolfazl; Fattahi, Fatemeh

2013-01-01

Purpose: The aim of this study was to design and formulation of potassium citrate effervescent tablet for reduction of calcium oxalate and urate kidney stones in patients suffering from kidney stones. Methods: In this study, 13 formulations were prepared from potassium citrate and effervescent base in different concentration. The flowability of powders and granules was studied. Then effervescent tablets were prepared by direct compression, fusion and wet granulation methods. The prepared tablets were evaluated for hardness, friability, effervescent time, pH, content uniformity. To amend taste of formulations, different flavoring agents were used and then panel test was done by using Latin Square method by 30 volunteers. Results: Formulations obtained from direct compression and fusion methods had good flow but low hardness. Wet granulation improves flowability and other physicochemical properties such as acceptable hardness, effervescence time ≤3 minutes, pH<6, friability < 1%, water percentage < 0.5% and accurate content uniformity. In panel test, both of combination flavors; (orange - lemon) and (strawberry - raspberry) had good acceptability. Conclusion: The prepared tablets by wet granulation method using PVP solution had more tablet hardness. It is a reproducible process and suitable to produce granules that are compressed into effervescent tablets due to larger agglomerates. PMID:24312839

Rheological properties of sewage sludge during enhanced anaerobic digestion with microwave-H2O2 pretreatment.

PubMed

Liu, Jibao; Yu, Dawei; Zhang, Jian; Yang, Min; Wang, Yawei; Wei, Yuansong; Tong, Juan

2016-07-01

The rheological behavior of sludge is of serious concern in anaerobic digestion. This study investigated the rheological properties of sewage sludge during enhanced anaerobic digestion with microwave-H2O2 pretreatment (MW-H2O2). The results showed that MW-H2O2 pretreatment resulted in the improvement of sludge flowability and weakening of its viscoelastic properties. Further positive effects on the rheological properties of digested sludge during anaerobic digestion were observed. The flowability was improved with a low level of apparent viscosity. The decrease of the consistency index and increase of the flow behavior index indicated that the strength of the inner structures and non-Newtonian flow characteristics of digested sludge weakened. Both the storage modulus (G') and loss modulus (G″) decreased, indicating that the viscoelastic behavior became weak. These effects were possibly attributed to the changes of the digested sludge micro-structures, such as extracellular polymeric substances (EPS). This study concluded that anaerobic digestion for treating sewage sludge combined with pretreatment is a more favorable option than single anaerobic digestion from the perspective of rheology. Copyright © 2016 Elsevier Ltd. All rights reserved.

Development of carvedilol-cyclodextrin inclusion complexes using fluid-bed granulation: a novel solid-state complexation alternative with technological advantages.

PubMed

Alonso, Ellen C P; Riccomini, Karina; Silva, Luis Antônio D; Galter, Daniela; Lima, Eliana M; Durig, Thomas; Taveira, Stephania F; Martins, Felipe Terra; Cunha-Filho, Marcílio S S; Marreto, Ricardo N

2016-10-01

This study sought to evaluate the achievement of carvedilol (CARV) inclusion complexes with modified cyclodextrins (HPβCD and HPγCD) using fluid-bed granulation (FB). The solid complexes were produced using FB and spray drying (SD) and were characterised by differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction, SEM, flowability and particle size analyses and in vitro dissolution. The DSC, FTIR and powder X-ray diffraction findings suggested successful CARV inclusion in the modified β- and γ-cyclodextrins, which was more evident in acidic media. The CARV dissolution rate was ~7-fold higher for complexes with both cyclodextrins prepared using SD than for raw CARV. Complexes prepared with HPβCD using FB also resulted in a significant improvement in dissolution rate (~5-fold) and presented superior flowability and larger particle size. The findings suggested that FB is the best alternative for large-scale production of solid dosage forms containing CARV. Additionally, the results suggest that HPγCD could be considered as another option for CARV complexation because of its excellent performance in inclusion complex formation in the solid state. © 2016 Royal Pharmaceutical Society.

Antibacterial, physical and mechanical properties of flowable resin composites containing zinc oxide nanoparticles.

PubMed

Tavassoli Hojati, Sara; Alaghemand, Homayoon; Hamze, Faeze; Ahmadian Babaki, Fateme; Rajab-Nia, Ramazan; Rezvani, Mohammad Bagher; Kaviani, Mehrnoosh; Atai, Mohammad

2013-05-01

The aim of this study is evaluating the antibacterial activity of resin composites containing ZnO nanoparticles against Streptococcus mutans and examining their physical and mechanical properties. The properties of flowable resin composites containing 0-5wt.% nano-ZnO are investigated using different tests: Although the agar diffusion test reveals no significant difference between the groups, the direct contact test demonstrates that by increasing the nanoparticle content, the bacterial growth is significantly diminished (p<0.05). In the aging test, however, the antibacterial properties reduce significantly (p<0.05). The flexural strength and compressive modulus remains unchanged by incorporation of nanoparticles (p>0.05) while the compressive strength and flexural modulus significantly increase (p<0.05). The ZnO containing resins show significantly lower depth of cure (p<0.05), and higher bond strength (p<0.05). There is no significant difference between the degrees of conversion, measured by FTIR technique, of the groups (p>0.05). Production of a dental resin composite with antibacterial activity without significant sacrificing effect on the mechanical properties is desirable in dental material science. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Interspecific variation in resistance to emerald ash borer (Coleoptera: Buprestidae) among North American and Asian ash (Fraxinus spp.).

PubMed

Rebek, Eric J; Herms, Daniel A; Smitley, David R

2008-02-01

We conducted a 3-yr study to compare the susceptibility of selected North American ash and an Asian ash species to emerald ash borer, Agrilus planipennis Fairmaire, an invasive wood-boring beetle introduced to North America from Asia. Because of a coevolutionary relationship between Asian ashes and emerald ash borer, we hypothesized an Asian ash species, Manchurian ash, is more resistant to the beetle than its North American congeners. Consistent with our hypothesis, Manchurian ash experienced far less mortality and yielded far fewer adult beetles than several cultivars of North American green and white ash. Surprisingly, a black ash (North American) x Manchurian ash hybrid was highly susceptible to emerald ash borer, indicating this cultivar did not inherit emerald ash borer resistance from its Asian parent. A corollary study investigated the efficacy of soil-applied imidacloprid, a systemic, neonicotinoid insecticide, for controlling emerald ash borer in each of the five cultivars. Imidacloprid had no effect on emerald ash borer colonization of Manchurian ash, which was low in untreated and treated trees. In contrast, imidacloprid did enhance survival of the North American and hybrid cultivars and significantly reduced the number of emerald ash borer adults emerging from green and white ash cultivars. We identify a possible mechanism of resistance of Manchurian ash to emerald ash borer, which may prove useful for screening, selecting, and breeding emerald ash borer-resistant ash trees.

Climate impacts of parameterized Nordic Sea overflows

NASA Astrophysics Data System (ADS)

Danabasoglu, Gokhan; Large, William G.; Briegleb, Bruce P.

2010-11-01

A new overflow parameterization (OFP) of density-driven flows through ocean ridges via narrow, unresolved channels has been developed and implemented in the ocean component of the Community Climate System Model version 4. It represents exchanges from the Nordic Seas and the Antarctic shelves, associated entrainment, and subsequent injection of overflow product waters into the abyssal basins. We investigate the effects of the parameterized Denmark Strait (DS) and Faroe Bank Channel (FBC) overflows on the ocean circulation, showing their impacts on the Atlantic Meridional Overturning Circulation and the North Atlantic climate. The OFP is based on the Marginal Sea Boundary Condition scheme of Price and Yang (1998), but there are significant differences that are described in detail. Two uncoupled (ocean-only) and two fully coupled simulations are analyzed. Each pair consists of one case with the OFP and a control case without this parameterization. In both uncoupled and coupled experiments, the parameterized DS and FBC source volume transports are within the range of observed estimates. The entrainment volume transports remain lower than observational estimates, leading to lower than observed product volume transports. Due to low entrainment, the product and source water properties are too similar. The DS and FBC overflow temperature and salinity properties are in better agreement with observations in the uncoupled case than in the coupled simulation, likely reflecting surface flux differences. The most significant impact of the OFP is the improved North Atlantic Deep Water penetration depth, leading to a much better comparison with the observational data and significantly reducing the chronic, shallow penetration depth bias in level coordinate models. This improvement is due to the deeper penetration of the southward flowing Deep Western Boundary Current. In comparison with control experiments without the OFP, the abyssal ventilation rates increase in the North Atlantic. In the uncoupled simulation with the OFP, the warm bias of the control simulation in the deep North Atlantic is substantially reduced along with salinity bias reductions in the northern North Atlantic. There are similar but more modest bias reductions in the deep temperature and salinity distributions especially in the northern North Atlantic in the coupled OFP case. In coupled simulations, there are noticeable impacts of the OFP on climate. The sea surface temperatures (SSTs) are warmer by more than 5°C off the North American coast and by more than 1°C in the Nordic Sea with the OFP. The surface heat fluxes mostly act to diminish these SST changes. There are related changes in the sea level pressure, leading to about 15% weaker westerly wind stress in the northern North Atlantic. In response to the warmer Nordic Sea SSTs, there are reductions in the sea ice extent, improving comparisons with observations. Although the OFP cases improve many aspects of the simulations compared to observations, some significant biases remain, more in coupled than in uncoupled simulations.

Growth of Larval Agrilus planipennis (Coleoptera: Buprestidae) and Fitness of Tetrastichus planipennisi (Hymenoptera: Eulophidae) in Blue Ash (Fraxinus quadrangulata) and Green Ash (F. pennsylvanica).

PubMed

Peterson, Donnie L; Duan, Jian J; Yaninek, J S; Ginzel, Matthew D; Sadof, Clifford S

2015-12-01

Emerald ash borer (Agrilus planipennis Fairmaire) is an invasive primary pest of North American ash (Fraxinus spp.) trees. Blue ash (F. quadrangulata) is less susceptible to emerald ash borer infestations in the forest than other species of North American ash. Whereas other studies have examined adult host preferences, we compared the capacity of emerald ash borer larvae reared from emerald ash borer eggs in the field and in the laboratory to survive and grow in blue ash and the more susceptible green ash (F. pennsylvanica). Emerald ash borer larval survivorship was the same on both ash species. Mortality due to wound periderm formation was only observed in living field grown trees, but was low (<4%) in both green and blue ash. No difference in larval mortality in the absence of natural enemies suggests that both green and blue ash can support the development of emerald ash borer. Larvae reared from eggs on blue ash were smaller than on green ash growing in the field and also in bolts that were infested under laboratory conditions. In a laboratory study, parasitism rates of confined Tetrastichus planipennisi were similar on emerald ash borer larvae reared in blue and green ash bolts, as were fitness measures of the parasitoid including brood size, sex ratio, and adult female size. Thus, we postulate that emerald ash borer larvae infesting blue ash could support populations of T. planipennisi and serve as a potential reservoir for this introduced natural enemy after most of the other native ash trees have been killed. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

BRAZING ALLOYS

DOEpatents

Donnelly, R.G.; Gilliland, R.G.; Slaughter, G.M.

1962-02-20

A brazing alloy is described which, in the molten state, is characterized by excellent wettability and flowability and is capable of forming a corrosion-resistant brazed joint. At least one component of said joint is graphite and the other component is a corrosion-resistant refractory metal. The brazing alloy consists essentially of 40 to 90 wt % of gold, 5 to 35 wt% of nickel, and 1 to 45 wt% of tantalum. (AEC)

Nanomechanical properties of dental resin-composites.

PubMed

El-Safty, S; Akhtar, R; Silikas, N; Watts, D C

2012-12-01

To determine by nanoindentation the hardness and elastic modulus of resin-composites, including a series with systematically varied filler loading, plus other representative materials that fall into the categories of flowable, bulk-fill and conventional nano-hybrid types. Ten dental resin-composites: three flowable, three bulk-fill and four conventional were investigated using nanoindentation. Disc specimens (15mm×2mm) were prepared from each material using a metallic mold. Specimens were irradiated in the mold at top and bottom surfaces in multiple overlapping points (40s each) with light curing unit at 650mW/cm(2). Specimens were then mounted in 3cm diameter phenolic ring forms and embedded in a self-curing polystyrene resin. After grinding and polishing, specimens were stored in distilled water at 37°C for 7 days. Specimens were investigated using an Agilent Technologies XP nanoindenter equipped with a Berkovich diamond tip (100nm radius). Each specimen was loaded at one loading rate and three different unloading rates (at room temperature) with thirty indentations, per unloading rate. The maximum load applied by the nanoindenter to examine the specimens was 10mN. Dependent on the type of the resin-composite material, the mean values ranged from 0.73GPa to 1.60GPa for nanohardness and from 14.44GPa to 24.07GPa for elastic modulus. There was a significant positive non-linear correlation between elastic modulus and nanohardness (r(2)=0.88). Nonlinear regression revealed a significant positive correlation (r(2)=0.62) between elastic moduli and filler loading and a non-significant correlation (r(2)=0.50) between nanohardness and filler loading of the studied materials. Varying the unloading rates showed no consistent effect on the elastic modulus and nanohardness of the studied materials. For a specific resin matrix, both elastic moduli and nanohardness correlated positively with filler loading. For the resin-composites investigated, the group-average elastic moduli and nanohardnesses for bulk-fill and flowable materials were lower than those for conventional nano-hybrid composites. Copyright © 2012 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Flowable resin and marginal gap on tooth third medial cavity involving enamel and radicular cementum: a SEM evaluation of two restoration techniques.

PubMed

Lo Giudice, G; Cicciù, M; Cervino, G; Lizio, A; Visco, A M

2012-01-01

The aim of this study is to investigate the presence and the extent of a possible marginal gap after the interposition of a flowable composite between the composite restoration and the dental structures (enamel and cementum). This technique is also used to eliminate the infiltration in a zone of the cavity preparation that is frequently at a risk of secondary decay. Fifteen human premolars extracted for orthodontic reasons were used for the study. A cavity with mesial and distal margin in enamel and cementum was realized in every tooth. The cavities were then restored with an adhesive system (ScotchBond 3MÔ) and composite (Filtek Supreme 3MÔ); and, a fine layer of flowable composite was applied in the distal margin of each cavity. Scanning electron microscopy (SEM) in secondary electron imaging (S.E.I.) modality was used for the study and identifying the marginal gaps in the composite restorations. Data was investigated on the mesial and distal margin of each cavity at the restoration-enamel interface, and at the restoration-cementum interface. The interfaces were divided in four groups: Group A (enamel/composite); Group B (enamel/flow/composite); Group C (cementum/composite); and, Group D (cementum/flow/composite). By the comparison of the gap's average width found in each group, it is evidenced that the average width of the gap increases when the interface moves from the coronal to the radicular end (Group A 0,1 ± 0,4 μm Vs Group C 12,3 ± 11,6 μm; Group B 0,2 ± 0,8 μm Vs Group D 2,8 ± 6,6 μm). Correlating the measurements of the marginal gap's average width among the Group A and Group B, no significant variations were obtained; and instead, on comparing Group C with Group D, the gap's average width decreases. The interposition of a low elastic modulus composite between the adhesive layer and the composite resin allows an improvement of the cementum-restoration interface by the means of a lower shrinkage stress during polymerization.

Occurrence of emerald ash borer (Coleoptera: Buprestidae) and biotic factors affecting its immature stages in the Russian Far East.

PubMed

Duan, Jian J; Yurchenko, Galina; Fuester, Roger

2012-04-01

Field surveys were conducted from 2008 to 2011 in the Khabarovsk and Vladivostok regions of Russia to investigate the occurrence of emerald ash borer, Agrilus planipennis Fairmaire, and mortality factors affecting its immature stages. We found emerald ash borer infesting both introduced North American green ash (Fraxinus pennsylvanica Marshall) and native oriental ashes (F. mandshurica Rupr. and F. rhynchophylla Hance) in both regions. Emerald ash borer densities (larvae/m(2) of phloem area) were markedly higher on green ash (11.3-76.7 in the Khabarovsk area and 77-245 in the Vladivostok area) than on artificially stressed Manchurian ash (2.2) or Oriental ash (10-59). Mortality of emerald ash borer larvae caused by different biotic factors (woodpecker predation, host plant resistance and/or undetermined diseases, and parasitism) varied with date, site, and ash species. In general, predation of emerald ash borer larvae by woodpeckers was low. While low rates (3-27%) of emerald ash borer larval mortality were caused by undetermined biotic factors on green ash between 2009 and 2011, higher rates (26-95%) of emerald ash borer larval mortality were caused by putative plant resistance in Oriental ash species in both regions. Little (<1%) parasitism of emerald ash borer larvae was observed in Khabarovsk; however, three hymenopteran parasitoids (Spathius sp., Atanycolus nigriventris Vojnovskaja-Krieger, and Tetrastichus planipennisi Yang) were observed attacking third - fourth instars of emerald ash borer in the Vladivostok area, parasitizing 0-8.3% of emerald ash borer larvae infesting Oriental ash trees and 7.3-62.7% of those on green ash trees (primarily by Spathius sp.) in two of the three study sites. Relevance of these findings to the classical biological control of emerald ash borer in newly invaded regions is discussed.

Interspecific Proteomic Comparisons Reveal Ash Phloem Genes Potentially Involved in Constitutive Resistance to the Emerald Ash Borer

PubMed Central

Whitehill, Justin G. A.; Popova-Butler, Alexandra; Green-Church, Kari B.; Koch, Jennifer L.; Herms, Daniel A.; Bonello, Pierluigi

2011-01-01

The emerald ash borer (Agrilus planipennis) is an invasive wood-boring beetle that has killed millions of ash trees since its accidental introduction to North America. All North American ash species (Fraxinus spp.) that emerald ash borer has encountered so far are susceptible, while an Asian species, Manchurian ash (F. mandshurica), which shares an evolutionary history with emerald ash borer, is resistant. Phylogenetic evidence places North American black ash (F. nigra) and Manchurian ash in the same clade and section, yet black ash is highly susceptible to the emerald ash borer. This contrast provides an opportunity to compare the genetic traits of the two species and identify those with a potential role in defense/resistance. We used Difference Gel Electrophoresis (DIGE) to compare the phloem proteomes of resistant Manchurian to susceptible black, green, and white ash. Differentially expressed proteins associated with the resistant Manchurian ash when compared to the susceptible ash species were identified using nano-LC-MS/MS and putative identities assigned. Proteomic differences were strongly associated with the phylogenetic relationships among the four species. Proteins identified in Manchurian ash potentially associated with its resistance to emerald ash borer include a PR-10 protein, an aspartic protease, a phenylcoumaran benzylic ether reductase (PCBER), and a thylakoid-bound ascorbate peroxidase. Discovery of resistance-related proteins in Asian species will inform approaches in which resistance genes can be introgressed into North American ash species. The generation of resistant North American ash genotypes can be used in forest ecosystem restoration and urban plantings following the wake of the emerald ash borer invasion. PMID:21949771

Interspecific proteomic comparisons reveal ash phloem genes potentially involved in constitutive resistance to the emerald ash borer.

PubMed

Whitehill, Justin G A; Popova-Butler, Alexandra; Green-Church, Kari B; Koch, Jennifer L; Herms, Daniel A; Bonello, Pierluigi

2011-01-01

The emerald ash borer (Agrilus planipennis) is an invasive wood-boring beetle that has killed millions of ash trees since its accidental introduction to North America. All North American ash species (Fraxinus spp.) that emerald ash borer has encountered so far are susceptible, while an Asian species, Manchurian ash (F. mandshurica), which shares an evolutionary history with emerald ash borer, is resistant. Phylogenetic evidence places North American black ash (F. nigra) and Manchurian ash in the same clade and section, yet black ash is highly susceptible to the emerald ash borer. This contrast provides an opportunity to compare the genetic traits of the two species and identify those with a potential role in defense/resistance. We used Difference Gel Electrophoresis (DIGE) to compare the phloem proteomes of resistant Manchurian to susceptible black, green, and white ash. Differentially expressed proteins associated with the resistant Manchurian ash when compared to the susceptible ash species were identified using nano-LC-MS/MS and putative identities assigned. Proteomic differences were strongly associated with the phylogenetic relationships among the four species. Proteins identified in Manchurian ash potentially associated with its resistance to emerald ash borer include a PR-10 protein, an aspartic protease, a phenylcoumaran benzylic ether reductase (PCBER), and a thylakoid-bound ascorbate peroxidase. Discovery of resistance-related proteins in Asian species will inform approaches in which resistance genes can be introgressed into North American ash species. The generation of resistant North American ash genotypes can be used in forest ecosystem restoration and urban plantings following the wake of the emerald ash borer invasion.

Treatment of fly ash for use in concrete

DOEpatents

Boxley, Chett [Park City, UT

2012-05-15

A process for treating fly ash to render it highly usable as a concrete additive. A quantity of fly ash is obtained that contains carbon and which is considered unusable fly ash for concrete based upon foam index testing. The fly ash is mixed with a quantity of spray dryer ash (SDA) and water to initiate a geopolymerization reaction and form a geopolymerized fly ash. The geopolymerized fly ash is granulated. The geopolymerized fly ash is considered usable fly ash for concrete according to foam index testing. The geopolymerized fly ash may have a foam index less than 40%, and in some cases less than 20%, of the foam index of the untreated fly ash. An optional alkaline activator may be mixed with the fly ash and SDA to facilitate the geopolymerization reaction. The alkaline activator may contain an alkali metal hydroxide, carbonate, silicate, aluminate, or mixtures thereof.

Treatment of fly ash for use in concrete

DOEpatents

Boxley, Chett [Park City, UT; Akash, Akash [Salt lake City, UT; Zhao, Qiang [Natick, MA

2012-05-08

A process for treating fly ash to render it highly usable as a concrete additive. A quantity of fly ash is obtained that contains carbon and which is considered unusable fly ash for concrete based upon foam index testing. The fly ash is mixed with an activator solution sufficient to initiate a geopolymerization reaction and for a geopolymerized fly ash. The geopolymerized fly ash is granulated. The geopolymerized fly ash is considered usable fly ash for concrete according to foam index testing. The geopolymerized fly ash may have a foam index less than 35% of the foam index of the untreated fly ash, and in some cases less than 10% of the foam index of the untreated fly ash. The activator solution may contain an alkali metal hydroxide, carbonate, silicate, aluminate, or mixtures thereof.

Treatment of fly ash for use in concrete

DOEpatents

Boxley, Chett; Akash, Akash; Zhao, Qiang

2013-01-08

A process for treating fly ash to render it highly usable as a concrete additive. A quantity of fly ash is obtained that contains carbon and which is considered unusable fly ash for concrete based upon foam index testing. The fly ash is mixed with an activator solution sufficient to initiate a geopolymerization reaction and for a geopolymerized fly ash. The geopolymerized fly ash is granulated. The geopolymerized fly ash is considered usable fly ash for concrete according to foam index testing. The geopolymerized fly ash may have a foam index less than 35% of the foam index of the untreated fly ash, and in some cases less than 10% of the foam index of the untreated fly ash. The activator solution may contain an alkali metal hydroxide, carbonate, silicate, aluminate, or mixtures thereof.

The High Teperature Influence on Geopolymer Fly Ash Mixture’s Compressisive Strength with Insudtrial Waste Material Substitution

NASA Astrophysics Data System (ADS)

Bayuaji, R.; Wibowo, B.; Subekti, S.; Santoso, S. E.; Hardiyanto, E.; Kaelani, Y.; Mallu, L. L.

2017-11-01

This research aimed to figure out the influence of fly ash mixture from the industrial waste at the temperatures of 150°C, 450°C, 750°C viewed from the strength and resistance of geopolymer paste. As a result, cement will be substituted by industrial waste like fly ash. This experimental research was conducted on the mix design of geopolymer concrete which was made by dimension with 2.5 cm in diameter and 5 cm in height from four mixture composition of fly ash and industrial waste i.e. 100% fly ash, 50% fly ash+50% bottom ash, 50% fly ash+50% sandblast, and 50% fly ash+50% carbide waste. Each mixture was tested in terms of porosity and compressive strength. In conclusion, in the mixture of 50% fly ash+50% Sandblast and 50% fly ash+50% bottom ash in 12 molars, 1.5 activator comparison can be used to substitute fly ash at high temperature. Meanwhile, the mixture of 50% fly ash+50% carbide waste in 8 molars, 0.5 activator comparison has very small strength remaining if it is compared to the mixture of fly ash and other industrial waste (Bottom ash and Sandblast). The performance of mixture paste of 50% fly ash+50% carbide waste was very vulnerable after being burnt. Consequently, it cannot be used as the main structure at high temperature.

An All-Sky Portable (ASP) Optical Catalogue

NASA Astrophysics Data System (ADS)

Flesch, Eric Wim

2017-06-01

This optical catalogue combines the all-sky USNO-B1.0/A1.0 and most-sky APM catalogues, plus overlays of SDSS optical data, into a single all-sky map presented in a sparse binary format that is easily downloaded at 9 Gb zipped. Total count is 1 163 237 190 sources and each has J2000 astrometry, red and blue magnitudes with PSFs and variability indicator, and flags for proper motion, epoch, and source survey and catalogue for each of the photometry and astrometry. The catalogue is available on http://quasars.org/asp.html, and additional data for this paper is available at http://dx.doi.org/10.4225/50/5807fbc12595f.

Nutritional and defensive chemistry of three North American ash species: possible roles in host performance and preference by emerald ash borer

Treesearch

Yigen Chen; Therese M. Poland

2010-01-01

Black ash (Fraxinus nigra), green ash (F. pennsylvanica), and white ash (F. americana) are the three most abundant ash species in the northeastern USA. We compared emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), adult performance and preference among seedlings...

Effects of nano-SiO(2) and different ash particle sizes on sludge ash-cement mortar.

PubMed

Lin, K L; Chang, W C; Lin, D F; Luo, H L; Tsai, M C

2008-09-01

The effects of nano-SiO(2) on three ash particle sizes in mortar were studied by replacing a portion of the cement with incinerated sewage sludge ash. Results indicate that the amount of water needed at standard consistency increased as more nano-SiO(2) was added. Moreover, a reduction in setting time became noticeable for smaller ash particle sizes. The compressive strength of the ash-cement mortar increased as more nano-SiO(2) was added. Additionally, with 2% nano-SiO(2) added and a cure length of 7 days, the compressive strength of the ash-cement mortar with 1 microm ash particle size was about 1.5 times better that of 75microm particle size. Further, nano-SiO(2) functioned to fill pores for ash-cement mortar with different ash particle sizes. However, the effects of this pore-filling varied with ash particle size. Higher amounts of nano-SiO(2) better influenced the ash-cement mortar with larger ash particle sizes.

Engineering Behavior and Characteristics of Wood Ash and Sugarcane Bagasse Ash

PubMed Central

Grau, Francisco; Choo, Hyunwook; Hu, Jong Wan; Jung, Jongwon

2015-01-01

Biomasses are organic materials that are derived from any living or recently-living structure. Plenty of biomasses are produced nationwide. Biomasses are mostly combusted and usually discarded or disposed of without treatment as biomass ashes, which include wood and sugarcane bagasse ashes. Thus, recycling or treatment of biomass ashes leads to utilizing the natural materials as an economical and environmental alternative. This study is intended to provide an environmental solution for uncontrolled disposal of biomass ashes by way of recycling the biomass ash and replacing the soils in geotechnical engineering projects. Therefore, in this study, characteristic tests of wood and sugarcane bagasse ashes that are considered the most common biomass ashes are conducted. The test of chemical compositions of biomass ashes is conducted using energy dispersive X-ray spectroscopy (EDS), and Scanning Electron Microscope (SEM), and heavy metal analysis is also conducted. Engineering behaviors including hydraulic conductivity, constrained modulus and shear modulus are examined. Also, coal fly ash Class C is used in this study for comparison with biomass ashes, and Ottawa 20/30 sands containing biomass ashes are examined to identify the soil replacement effect of biomass ashes. The results show that the particle sizes of biomass ashes are halfway between coal fly ash Class C and Ottawa 20/30 sand, and biomass ashes consist of a heterogeneous mixture of different particle sizes and shapes. Also, all heavy metal concentrations were found to be below the US Environmental Protection Agency (EPA) maximum limit. Hydraulic conductivity values of Ottawa 20/30 sand decrease significantly when replacing them with only 1%–2% of biomass ashes. While both the constrained modulus and shear modulus of biomass ashes are lower than Ottawa 20/30 sand, those of mixtures containing up to 10% biomass ashes are little affected by replacing the soils with biomass ashes. PMID:28793611

CO.sub.2 utilization in electrochemical systems

DOEpatents

Boxley, Chett; Akash, Akash; Zhao, Qiang

2013-01-22

A process for treating fly ash to render it highly usable as a concrete additive. A quantity of fly ash is obtained that contains carbon and which is considered unusable fly ash for concrete based upon foam index testing. The fly ash is mixed with a quantity of spray dryer ash (SDA) and water to initiate a geopolymerization reaction and form a geopolymerized fly ash. The geopolymerized fly ash is granulated. The geopolymerized fly ash is considered usable fly ash for concrete according to foam index testing. The geopolymerized fly ash may have a foam index less than 40%, and in some cases less than 20%, of the foam index of the untreated fly ash. An optional alkaline activator may be mixed with the fly ash and SDA to facilitate the geopolymerization reaction. The alkaline activator may contain an alkali metal hydroxide, carbonate, silicate, aluminate, or mixtures thereof.

Cocrystal habit engineering to improve drug dissolution and alter derived powder properties.

PubMed

Serrano, Dolores R; O'Connell, Peter; Paluch, Krzysztof J; Walsh, David; Healy, Anne Marie

2016-05-01

Cocrystallization of sulfadimidine (SDM) with suitable coformers, such as 4-aminosalicylic acid (4-ASA), combined with changes in the crystal habit can favourably alter its physicochemical properties. The aim of this work was to engineer SDM : 4-ASA cocrystals with different habits to investigate the effect on dissolution, and the derived powder properties of flow and compaction. Cocrystals were prepared in a 1 : 1 molar ratio by solvent evaporation using ethanol (habit I) or acetone (habit II), solvent evaporation followed by grinding (habit III) and spray drying (habit IV). Powder X-ray diffraction showed Bragg peak position was the same in all the solid products. The peak intensity varied, indicating different preferred crystal orientation confirmed by SEM micrographs: large prismatic crystals (habit I), large plate-like crystals (habit II), small cube-like crystals (habit III) and microspheres (habit IV). The habit III exhibited the fasted dissolution rate; however, it underwent a polymorphic transition during dissolution. Habits I and IV exhibited the highest Carr's compressibility index, indicating poor flowability. However, habits II and III demonstrated improved flow. Spray drying resulted in cocrystals with improved compaction properties. Even for cocrystals with poor pharmaceutical characteristics, a habit can be engineered to alter the dissolution, flowability and compaction behaviour. © 2015 Royal Pharmaceutical Society.

Influence of Excipients and Spray Drying on the Physical and Chemical Properties of Nutraceutical Capsules Containing Phytochemicals from Black Bean Extract.

PubMed

Guajardo-Flores, Daniel; Rempel, Curtis; Gutiérrez-Uribe, Janet A; Serna-Saldívar, Sergio O

2015-12-03

Black beans (Phaseolus vulgaris L.) are a rich source of flavonoids and saponins with proven health benefits. Spray dried black bean extract powders were used in different formulations for the production of nutraceutical capsules with reduced batch-to-batch weight variability. Factorial designs were used to find an adequate maltodextrin-extract ratio for the spray-drying process to produce black bean extract powders. Several flowability properties were used to determine composite flow index of produced powders. Powder containing 6% maltodextrin had the highest yield (78.6%) and the best recovery of flavonoids and saponins (>56% and >73%, respectively). The new complexes formed by the interaction of black bean powder with maltodextrin, microcrystalline cellulose 50 and starch exhibited not only bigger particles, but also a rougher structure than using only maltodextrin and starch as excipients. A drying process prior to capsule production improved powder flowability, increasing capsule weight and reducing variability. The formulation containing 25.0% of maltodextrin, 24.1% of microcrystalline cellulose 50, 50% of starch and 0.9% of magnesium stearate produced capsules with less than 2.5% weight variability. The spray drying technique is a feasible technique to produce good flow extract powders containing valuable phytochemicals and low cost excipients to reduce the end-product variability.

In situ distributed diagnostics of flowable electrode systems: resolving spatial and temporal limitations.

PubMed

Dennison, C R; Gogotsi, Y; Kumbur, E C

2014-09-14

In this study, we have developed an in situ distributed diagnostics tool to investigate spatial and temporal effects in electrochemical systems based on flowable electrodes. Specifically, an experimental approach was developed that enables spatially-resolved voltage measurements to be obtained in situ, in real-time. To extract additional data from these distributed measurements, an experimentally-parameterized equivalent circuit model with a new 'flow capacitor' circuit element was developed to predict the distributions of various system parameters during operation. As a case study, this approach was applied to investigate the behavior of the suspension electrodes used in an electrochemical flow capacitor under flowing and static conditions. The volumetric capacitance is reduced from 15.6 F ml(-1) to 1.1 F ml(-1) under flowing conditions. Results indicate that the majority of the charging in suspension electrodes occurs within ∼750 μm of the current collectors during flow, which gives rise to significant state-of-charge gradients across the cell, as well as underutilization of the available active material. The underlying cause of this observation is attributed to the relatively high electrical resistance of the slurry coupled with a stratified charging regime and insufficient residence time. The observations highlight the need to develop more conductive slurries and to design cells with reduced charge transport lengths.

Engineering and functional properties of biodegradable pellets developed from various agro-industrial wastes using extrusion technology.

PubMed

Jan, Kulsum; Riar, C S; Saxena, D C

2015-12-01

Different agro-industrial wastes were mixed with different plasticizers and extruded to form the pellets to be used further for development of biodegradable molded pots. Bulk density and macro-porosity are the important engineering properties used to determine the functional characteristics of the biodegradable pellets viz., expansion volume, water solubility, product colour, flowability and compactness. Significant differences in the functional properties of pellets with varying bulk densities (loose and tapped) and macro-porosities (loose, tapped) were observed. The observed mean bulk density of biodegradable pellets made from different formulations ranged between 0.213 and 0.560 g/ml for loose fill conditions and 0.248 to 0.604 g/ml for tapped fill conditions. Biodegradable pellets bear a good compaction for both loose and tapped fill methods. The mean macro-porosity of biodegradable pellets ranged between 1.19 and 54.48 % for loose fill condition and 0.29 to 53.35 % for tapped fill condition. Hausner ratio (HR) for biodegradable pellets varied from 1.026 to 1.328, indicating a good flowability of biodegradable pellets. Pearson's correlation between engineering properties and functional properties of biodegradable pellets revealed that from engineering properties functional properties can be predicted.

Acellular Flowable Matrix in the Treatment of Tunneled or Cavity Ulcers in Diabetic Feet: A Preliminary Report.

PubMed

Campitiello, Ferdinando; Mancone, Manfredi; Della Corte, Angela; Guerniero, Raffaella; Canonico, Silvestro

2018-06-01

The authors aimed to explore the feasibility and safety of an advanced, acellular, flowable wound matrix (FWM) in patients with diabetes-related cavity or tunnel lesions involving deep structures. Patients with diabetic foot ulcers were hospitalized at the General and Geriatric Surgery Unit of the University of Campania in Naples, Italy, between March 2015 and December 2015. Twenty-three patients with tunneled or cavity ulcers were treated. The lesions were filled with the FWM. Surgical wound edges were either approximated with stitches or left to heal by secondary intention. After 6 weeks, 78.26% of patients completely healed after a single application of the FWM. The healing time for all healed wounds was 30.85 ± 12.62 days, or 26.11 ± 5.43 days in patients for whom wound edges were approximated by stitches, and 57.66 ± 3.05 days in the patients who healed by secondary intention (P = .01). Permanent tissue regeneration was observed in a high percentage of patients, and shorter healing time was achieved. Study authors observed a low rate of complications such as major amputation and increased hospitalization. The FWM seems ideal for tunneled and cavity ulcers with irregular geometry. This new porous matrix allows closure of the lesion while reducing healing time and demolition surgery.

Relationships between surface coverage ratio and powder mechanics of binary adhesive mixtures for dry powder inhalers.

PubMed

Rudén, Jonas; Frenning, Göran; Bramer, Tobias; Thalberg, Kyrre; Alderborn, Göran

2018-04-25

The aim of this paper was to study relationships between the content of fine particles and the powder mechanics of binary adhesive mixtures and link these relationships to the blend state. Mixtures with increasing amounts of fine particles (increasing surface coverage ratios (SCR)) were prepared using Lactopress SD as carrier and micro particles of lactose as fines (2.7 µm). Indicators of unsettled bulk density, compressibility and flowability were derived and the blend state was visually examined by imaging. The powder properties studied showed relationships to the SCR characterised by stages. At low SCR, the fine particles predominantly gathered in cavities of the carriers, giving increased bulk density and unchanged or improved flow. Thereafter, increased SCR gave a deposition of particles at the enveloped carrier surface with a gradually more irregular adhesion layer leading to a reduced bulk density and a step-wise reduced flowability. The mechanics of the mixtures at a certain stage were dependent on the structure and the dynamics of the adhesion layer and transitions between the stages were controlled by the evolution of the adhesion layer. It is advisable to use techniques based on different types of flow in order to comprehensively study the mechanics of adhesive mixtures. Copyright © 2018 Elsevier B.V. All rights reserved.

Enhancement in in vitro anti-angiogenesis activity and cytotoxicity in lung cancer cell by pectin-PVP based curcumin particulates.

PubMed

Gaikwad, Dinanath; Shewale, Rajnita; Patil, Vinit; Mali, Dipak; Gaikwad, Uday; Jadhav, Namdeo

2017-11-01

The aim of this work was to prepare pectin-poly (vinyl pyrrolidone) [PVP] based curcumin particulates to enhance the anticancer potential of curcumin, solubility and allow its localized controlled release. Pectin-PVP based curcumin particulates (PECTIN-PVP CUR) were prepared by spray drying technique in different ratios and were evaluated for surface morphology, micromeritics, flowability, particle size, drug content, in vitro dissolution, inhalable fraction, anti-angiogenesis/angiolysis and cytotoxicity. Results of micromeritic properties, Carr's index, Hausner's ratio and angle of repose were satisfactory. The batch CP3 was considered as optimum, due to excellent flowability, acceptable aggregation and enhanced solubility. The particle size and size distribution data of selected batch CP3 showed 90% of curcumin particulates having size less than 2.74μm, which may deposit to lungs. Twin Impinger studies showed that 29% of respirable fraction was generated, which could be directly delivered to lungs. The in vitro dissolution data showed many fold increase in dissolution rate. Angiolytic activity and MTT assay of PECTIN-PVP CUR have demonstrated enhancement in the anti-tumor potential, compared to curcumin alone. Altogether, PECTIN-PVP CUR were found suitable for local delivery and enhance its anticancer potential of curcumin. Copyright © 2017 Elsevier B.V. All rights reserved.

Influence of coating material on the flowability and dissolution of dry-coated fine ibuprofen powders.

PubMed

Qu, Li; Zhou, Qi Tony; Denman, John A; Stewart, Peter J; Hapgood, Karen P; Morton, David A V

2015-10-12

This study investigates the effects of a variety of coating materials on the flowability and dissolution of dry-coated cohesive ibuprofen powders, with the ultimate aim to use these in oral dosage forms. A mechanofusion approach was employed to apply a 1% (w/w) dry coating onto ibuprofen powder with coating materials including magnesium stearate (MgSt), L-leucine, sodium stearyl fumarate (SSF) and silica-R972. No significant difference in particle size or shape was measured following mechanofusion with any material. Powder flow behaviours characterised by the Freeman FT4 system indicated coatings of MgSt, L-leucine and silica-R972 produced a notable surface modification and substantially improved flow compared to the unprocessed and SSF-mechanofused powders. ToF-SIMS provided a qualitative measure of coating extent, and indicated a near-complete layer on the drug particle surface after dry coating with MgSt or silica-R972. Of particular note, the dissolution rates of all mechanofused powders were enhanced even with a coating of a highly hydrophobic material such as magnesium stearate. This surprising increase in dissolution rate of the mechanofused powders was attributed to the lower cohesion and the reduced agglomeration after mechanical coating. Copyright © 2015 Elsevier B.V. All rights reserved.

Interspecific proteomic comparisons reveal ash phloem genes potentially involved in constitutive resistance to the emerald ash borer

Treesearch

Justin G.A. Whitehill; Alexandra Popova-Butler; Kari B. Green-Church; Jennifer L. Koch; Daniel A. Herms; Pierluigi Bonello

2011-01-01

The emerald ash borer (Agrilus planipennis) is an invasive wood-boring beetle that has killed millions of ash trees since its accidental introduction to North America. All North American ash species (Fraxinus spp.) that emerald ash borer has encountered so far are susceptible, while an Asian species, Manchurian ash (F....

Ash Analysis

NASA Astrophysics Data System (ADS)

Marshall, Maurice R.

Ash refers to the inorganic residue remaining after either ignition or complete oxidation of organic matter in a foodstuff. A basic knowledge of the characteristics of various ashing procedures and types of equipment is essential to ensure reliable results. Two major types of ashing are used: dry ashing, primarily for proximate composition and for some types of specific mineral analyses; wet ashing (oxidation), as a preparation for the analysis of certain minerals. Microwave systems now are available for both dry and wet ashing, to speed the processes. Most dry samples (i.e., whole grain, cereals, dried vegetables) need no preparation, while fresh vegetables need to be dried prior to ashing. High-fat products such as meats may need to be dried and fat extracted before ashing. The ash content of foods can be expressed on either a wet weight (as is) or on a dry weight basis. For general and food-specific information on measuring ash content, see references (1-11).

The Australasian Psoriasis Collaboration view on methotrexate for psoriasis in the Australasian setting.

PubMed

Rademaker, Marius; Gupta, Monisha; Andrews, Megan; Armour, Katherine; Baker, Chris; Foley, Peter; Gebauer, Kurt; George, Jacob; Rubel, Diana; Sullivan, John

2017-08-01

The Australasian Psoriasis Collaboration reviewed methotrexate (MTX) in the management of psoriasis in the Australian and New Zealand setting. The following comments are based on expert opinion and a literature review. Low-dose MTX (< 0.4 mg/kg per week) has a slow onset of action and has moderate to good efficacy, together with an acceptable safety profile. The mechanism of action is anti-inflammatory, rather than immunosuppressive. For pretreatment, consider testing full blood count (FBC), liver and renal function, non-fasting lipids, hepatitis serology, HbA1c and glucose. Body mass index and abdominal circumference should also be measured. Optional investigations in at-risk groups include an HIV test, a QuantiFERON-TB Gold test and a chest X-ray. In patients without complications, repeat the FBC at 2-4 weeks, then every 3-6 months and the liver/renal function test at 3 months and then every 6 months. There is little evidence that a MTX test dose is of value. Low-dose MTX rarely causes clinically significant hepatotoxicity in psoriasis. Most treatment-emergent liver toxicity is related to underlying metabolic syndrome and non-alcoholic fatty liver disease or non-alcoholic steatohepatitis. Alcohol itself is not contraindicated, but should be limited to < 20 gm/day. [Correction added on 6 January 2017, after first online publication: '20 mg/day' has been corrected to '20 gm/day'.] Although MTX is a potential teratogen post-conception, there is little evidence for this pre-conception. MTX does not affect the quality of sperm. There is no evidence that MTX reduces healing, so there is no specific need to stop MTX peri-surgery. MTX may be used in combination with cyclosporine, acitretin, prednisone and anti-tumour necrosis factor biologics. © 2016 The Australasian College of Dermatologists.

Whole-exome sequencing and targeted gene sequencing provide insights into the role of PALB2 as a male breast cancer susceptibility gene.

PubMed

Silvestri, Valentina; Zelli, Veronica; Valentini, Virginia; Rizzolo, Piera; Navazio, Anna Sara; Coppa, Anna; Agata, Simona; Oliani, Cristina; Barana, Daniela; Castrignanò, Tiziana; Viel, Alessandra; Russo, Antonio; Tibiletti, Maria Grazia; Zanna, Ines; Masala, Giovanna; Cortesi, Laura; Manoukian, Siranoush; Azzollini, Jacopo; Peissel, Bernard; Bonanni, Bernardo; Peterlongo, Paolo; Radice, Paolo; Palli, Domenico; Giannini, Giuseppe; Chillemi, Giovanni; Montagna, Marco; Ottini, Laura

2017-01-01

Male breast cancer (MBC) is a rare disease whose etiology appears to be largely associated with genetic factors. BRCA1 and BRCA2 mutations account for about 10% of all MBC cases. Thus, a fraction of MBC cases are expected to be due to genetic factors not yet identified. To further explain the genetic susceptibility for MBC, whole-exome sequencing (WES) and targeted gene sequencing were applied to high-risk, BRCA1/2 mutation-negative MBC cases. Germ-line DNA of 1 male and 2 female BRCA1/2 mutation-negative breast cancer (BC) cases from a pedigree showing a first-degree family history of MBC was analyzed with WES. Targeted gene sequencing for the validation of WES results was performed for 48 high-risk, BRCA1/2 mutation-negative MBC cases from an Italian multicenter study of MBC. A case-control series of 433 BRCA1/2 mutation-negative MBC and female breast cancer (FBC) cases and 849 male and female controls was included in the study. WES in the family identified the partner and localizer of BRCA2 (PALB2) c.419delA truncating mutation carried by the proband, her father, and her paternal uncle (all affected with BC) and the N-acetyltransferase 1 (NAT1) c.97C>T nonsense mutation carried by the proband's maternal aunt. Targeted PALB2 sequencing detected the c.1984A>T nonsense mutation in 1 of the 48 BRCA1/2 mutation-negative MBC cases. NAT1 c.97C>T was not found in the case-control series. These results add strength to the evidence showing that PALB2 is involved in BC risk for both sexes and indicate that consideration should be given to clinical testing of PALB2 for BRCA1/2 mutation-negative families with multiple MBC and FBC cases. Cancer 2017;123:210-218. © 2016 American Cancer Society. © 2016 American Cancer Society.

Addition of Rice Bran Arabinoxylan to Curcumin Therapy May Be of Benefit to Patients With Early-Stage B-Cell Lymphoid Malignancies (Monoclonal Gammopathy of Undetermined Significance, Smoldering Multiple Myeloma, or Stage 0/1 Chronic Lymphocytic Leukemia)

PubMed Central

Golombick, Terry; Diamond, Terrence H.; Manoharan, Arumugam; Ramakrishna, Rajeev

2016-01-01

Hypothesis. Prior studies on patients with early B-cell lymphoid malignancies suggest that early intervention with curcumin may lead to delay in progressive disease and prolonged survival. These patients are characterized by increased susceptibility to infections. Rice bran arabinoxylan (Ribraxx) has been shown to have immunostimulatory, anti-inflammatory, and proapoptotic effects. We postulated that addition of Ribraxx to curcumin therapy may be of benefit. Study design. Monoclonal gammopathy of undetermined significance (MGUS)/smoldering multiple myeloma (SMM) or stage 0/1 chronic lymphocytic leukemia (CLL) patients who had been on oral curcumin therapy for a period of 6 months or more were administered both curcumin (as Curcuforte) and Ribraxx. Methods. Ten MGUS/SMM patients and 10 patients with stage 0/1 CLL were administered 6 g of curcumin and 2 g Ribraxx daily. Blood samples were collected at baseline and at 2-month intervals for a period of 6 months, and various markers were monitored. MGUS/SMM patients included full blood count (FBC); paraprotein; free light chains/ratio; C-reactive protein (CRP)and erythrocyte sedimentation rate (ESR); B2 microglobulin and immunological markers. Markers monitored for stage 0/1 CLL were FBC, CRP and ESR, and immunological markers. Results. Of 10 MGUS/SMM patients,5 (50%) were neutropenic at baseline, and the Curcuforte/Ribraxx combination therapy showed an increased neutrophil count, varying between 10% and 90% among 8 of the 10 (80%) MGUS/SMM patients. An additional benefit of the combination therapy was the potent effect in reducing the raised ESR in 4 (44%) of the MGUS/SMM patients. Conclusion. Addition of Ribraxx to curcumin therapy may be of benefit to patients with early-stage B-cell lymphoid malignancies. PMID:27154182

Proceedings of symposium on ash in North America

Treesearch

Charles H. Michler; Matthew D., eds. Ginzel

2010-01-01

Includes 5 papers and 30 abstracts covering topics related to the biology and ecology of the ash species, ash utilization and management, emerald ash borer, and other threats to ash, and genetics and conservation of ash species. A paper titled "Population-level variation of Fraxinus americana L. is influenced by climate...

40 CFR 302.6 - Notification requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

... transportation of coal and coal ash (including fly ash, bottom ash, and boiler slags), including the dumping and... coal and coal ash, including fly ash, bottom ash, and boiler slags. (d) Except for releases of..., chromium, copper, lead, nickel, selenium, silver, thallium, or zinc is not required if the mean diameter of...

Study on Strength Behavior of Organic Soil Stabilized with Fly Ash

PubMed Central

Molla, Md. Keramat Ali; Sarkar, Grytan

2017-01-01

The aim of this study is to investigate the effect of fly ash on the consistency, compactness, acidic properties, and strength of organic soil. The presence of organic content in the soil has detrimental impacts on the physical and strength behavior of soil. To investigate the effectiveness of fly ash in the stabilization of organic soil, two types of fly ashes (Type I and Type II) at different percentages were used. It is found that fly ash significantly reduces the plasticity index of the organic soil, whereas the liquid and plastic limits increase. The dry density of the fly ash-soil mixture increases significantly, while the water requirement reduces due to the addition of fly ash. The increase of dry density compromises higher strength. The increase of qu with the increase of fly ash content is mainly due to the pozzolanic reaction of fly ash, although the reduction in water content results from the addition of dry fly ash solid. Moreover, Type I fly ash contributes a higher value of qu compared to Type II fly ash. This is attributed to the characteristics of fly ash including CaO and CaO/SiO2 ratio. PMID:29085881

Wood Ash Induced pH Changes Strongly Affect Soil Bacterial Numbers and Community Composition

PubMed Central

Bang-Andreasen, Toke; Nielsen, Jeppe T.; Voriskova, Jana; Heise, Janine; Rønn, Regin; Kjøller, Rasmus; Hansen, Hans C. B.; Jacobsen, Carsten S.

2017-01-01

Recirculation of wood ash from energy production to forest soil improves the sustainability of this energy production form as recycled wood ash contains nutrients that otherwise would be lost at harvest. In addition, wood-ash is beneficial to many soils due to its inherent acid-neutralizing capabilities. However, wood ash has several ecosystem-perturbing effects like increased soil pH and pore water electrical conductivity both known to strongly impact soil bacterial numbers and community composition. Studies investigating soil bacterial community responses to wood ash application remain sparse and the available results are ambiguous and remain at a general taxonomic level. Here we investigate the response of bacterial communities in a spruce forest soil to wood ash addition corresponding to 0, 5, 22, and 167 t wood ash ha-1. We used culture-based enumerations of general bacteria, Pseudomonas and sporeforming bacteria combined with 16S rRNA gene amplicon sequencing to valuate soil bacterial responses to wood ash application. Results showed that wood ash addition strongly increased soil pH and electrical conductivity. Soil pH increased from acidic through neutral at 22 t ha-1 to alkaline at 167 t ha-1. Bacterial numbers significantly increased up to a wood ash dose of 22 t ha-1 followed by significant decrease at 167 t ha-1 wood ash. The soil bacterial community composition changed after wood ash application with copiotrophic bacteria responding positively up to a wood ash dose of 22 t ha-1 while the adverse effect was seen for oligotrophic bacteria. Marked changes in bacterial community composition occurred at a wood ash dose of 167 t ha-1 with a single alkaliphilic genus dominating. Additionally, spore-formers became abundant at an ash dose of 167 t ha-1 whereas this was not the case at lower ash doses. Lastly, bacterial richness and diversity strongly decreased with increasing amount of wood ash applied. All of the observed bacterial responses can be directly explained by the wood ash induced changes in pH, electrical conductivity and the addition of wood ash inherent nutrients. PMID:28804476

Wood Ash Induced pH Changes Strongly Affect Soil Bacterial Numbers and Community Composition.

PubMed

Bang-Andreasen, Toke; Nielsen, Jeppe T; Voriskova, Jana; Heise, Janine; Rønn, Regin; Kjøller, Rasmus; Hansen, Hans C B; Jacobsen, Carsten S

2017-01-01

Recirculation of wood ash from energy production to forest soil improves the sustainability of this energy production form as recycled wood ash contains nutrients that otherwise would be lost at harvest. In addition, wood-ash is beneficial to many soils due to its inherent acid-neutralizing capabilities. However, wood ash has several ecosystem-perturbing effects like increased soil pH and pore water electrical conductivity both known to strongly impact soil bacterial numbers and community composition. Studies investigating soil bacterial community responses to wood ash application remain sparse and the available results are ambiguous and remain at a general taxonomic level. Here we investigate the response of bacterial communities in a spruce forest soil to wood ash addition corresponding to 0, 5, 22, and 167 t wood ash ha -1 . We used culture-based enumerations of general bacteria, Pseudomonas and sporeforming bacteria combined with 16S rRNA gene amplicon sequencing to valuate soil bacterial responses to wood ash application. Results showed that wood ash addition strongly increased soil pH and electrical conductivity. Soil pH increased from acidic through neutral at 22 t ha -1 to alkaline at 167 t ha -1 . Bacterial numbers significantly increased up to a wood ash dose of 22 t ha -1 followed by significant decrease at 167 t ha -1 wood ash. The soil bacterial community composition changed after wood ash application with copiotrophic bacteria responding positively up to a wood ash dose of 22 t ha -1 while the adverse effect was seen for oligotrophic bacteria. Marked changes in bacterial community composition occurred at a wood ash dose of 167 t ha -1 with a single alkaliphilic genus dominating. Additionally, spore-formers became abundant at an ash dose of 167 t ha -1 whereas this was not the case at lower ash doses. Lastly, bacterial richness and diversity strongly decreased with increasing amount of wood ash applied. All of the observed bacterial responses can be directly explained by the wood ash induced changes in pH, electrical conductivity and the addition of wood ash inherent nutrients.

Properties of Fly Ash Blocks Made from Adobe Mould

NASA Astrophysics Data System (ADS)

Chokhani, Alankrit; Divakar, B. S.; Jawalgi, Archana S.; Renukadevi, M. V.; Jagadish, K. S.

2018-02-01

Fly ash being one of the industrial waste products poses a serious disposal problem. This paper presents an experimental study of utilization of fly ash to produce blocks with varying proportions and mix combinations. Composition of fly ash blocks mainly consist of fly ash and sand, with cementitious product as either cement, lime or both, such as fly ash-sand-cement, fly ash-sand-lime and fly ash-sand-cement-lime are used. Four different proportions for each of the mix combinations are experimented. Compressive strength, water absorption, Initial rate of absorption, and dry density of fly ash blocks are studied. The influence of partial and complete replacement of cement by lime is examined.

Properties of Fly Ash Blocks Made from Adobe Mould

NASA Astrophysics Data System (ADS)

Chokhani, Alankrit; Divakar, B. S.; Jawalgi, Archana S.; Renukadevi, M. V.; Jagadish, K. S.

2018-06-01

Fly ash being one of the industrial waste products poses a serious disposal problem. This paper presents an experimental study of utilization of fly ash to produce blocks with varying proportions and mix combinations. Composition of fly ash blocks mainly consist of fly ash and sand, with cementitious product as either cement, lime or both, such as fly ash-sand-cement, fly ash-sand-lime and fly ash-sand-cement-lime are used. Four different proportions for each of the mix combinations are experimented. Compressive strength, water absorption, Initial rate of absorption, and dry density of fly ash blocks are studied. The influence of partial and complete replacement of cement by lime is examined.

Investigation on Leaching Behaviour of Fly Ash and Bottom Ash Replacement in Self-Compacting Concrete

NASA Astrophysics Data System (ADS)

Kadir, Aeslina Abdul; Ikhmal Haqeem Hassan, Mohd; Bakri Abdullah, Mohd Mustafa Al

2016-06-01

Fly ash and bottom ash are some of the waste generated by coal-fired power plants, which contains large quantities of toxic and heavy metals. In recent years, many researchers have been interested in studying on the properties of self-compacting concrete incorporated with fly ash and bottom ash but there was very limited research from the combination of fly ash and bottom ash towards the environmental needs. Therefore, this research was focused on investigating the leachability of heavy metals of SCC incorporated with fly ash and bottom ash by using Toxicity Characteristic Leaching Procedure, Synthetic Precipitation Leaching Procedure and Static Leaching Test. The samples obtained from the coal-fired power plant located at Peninsula, Malaysia. In this study, the potential heavy metals leached out from SCC that is produced with fly ash as a replacement for Ordinary Portland Cement and bottom ash as a substitute for sand with the ratios from 10% to 30% respectively were designated and cast. There are eight heavy metals of concern such as As, Cr, Pb, Zn, Cu, Ni, Mn and Fe. The results indicated that most of the heavy metals leached below the permissible limits from the United States Environmental Protection Agency and World Health Organization limit for drinking water. As a conclusion, the minimum leaching of the heavy metals from the incorporation of fly ash and bottom ash in self-compacting concrete was found in 20% of fly ash and 20% of bottom ash replacement. The results also indicate that this incorporation could minimize the potential of environmental problems.

Differential response in foliar chemistry of three ash species to emerald ash borer adult feeding.

PubMed

Chen, Yigen; Whitehill, Justin G A; Bonello, Pierluigi; Poland, Therese M

2011-01-01

The emerald ash borer (EAB; Agrilus planipennis Fairmaire; Coleoptera: Buprestidae), is an exotic wood-boring beetle that has been threatening North American ash (Fraxinus spp.) resources since its discovery in Michigan and Ontario in 2002. In this study, we investigated the phytochemical responses of the three most common North American ash species (black, green, and white ash) in northeastern USA to EAB adult feeding. Black ash was the least responsive to EAB adult feeding in terms of the induction of volatile compounds, and levels of only two (indole and benzyl cyanide) of the 11 compounds studied increased. In green ash, levels of two [(E)-β-ocimene and indole] of the 11 volatile compounds studied were elevated, while the levels of two green leaf volatiles [hexanal and (E)-2-hexenal] decreased. White ash showed the greatest response with an increase in levels of seven of the 11 compounds studied. Qualitative differences among ash species were detected. Among the phenolic compounds detected, ligustroside was the only one detected in all three species. Oleuropein aglycone and 2 unidentified compounds were found only in black ash; coumaroylquinic acid and feruloylquinic acid were detected only in green ash; and verbascoside hexoside was detected only in white ash. EAB adult feeding did not elicit or decrease concentrations of any selected individual phenolic compounds. However, although levels of total phenolics from black and green ash foliage were not affected by EAB adult feeding, they decreased significantly in white ash. EAB adult feeding elevated chymotrypsin inhibitors in black ash. The possible ecological implications of these findings are discussed.

“Faster, better, and cheaper” at NASA: Lessons learned in managing and accepting risk

NASA Astrophysics Data System (ADS)

Paxton, Larry J.

2007-11-01

Can Earth observing missions be done "better, faster and cheaper"? In this paper I explore the management and technical issues that arose from the attempt to do things "faster, better and cheaper" at NASA. The FBC mantra lead to some failures and, more significantly, an increase in the cadence of missions. Mission cadence is a major enabler of innovation and the driver for the training and testing of the next generation of managers, engineers, and scientists. A high mission cadence is required to maintain and develop competence in mission design, management, and execution and, for an exploration-driven organization, to develop and train the next generation of leaders: the time between missions must be short enough that careers span the complete life of more than a few missions. This process reduces risk because the "lessons learned" are current and widely held. Increasing the cadence of missions has the added benefit of reducing the pressure to do everything on one particular mission thus reducing mission complexity. Since failures are inevitable in such a complex endeavor, a higher mission cadence has the advantage of providing some resiliency to the scientific program the missions support. Some failures are avoidable (often only in hindsight) but most are due to some combination of interacting factors. This interaction is often only appreciated as a potential failure mode after the fact. There is always the pressure to do more with less: the scope of the project may become too ambitious or the management and oversight of the project may be reduced to fit the money allocated, or the project time line may be lengthened due to external factors (launcher availability, budgetary constraints) without a concomitant increase in the total funding. This leads to increased risk. Risks are always deemed acceptable until they change from a "risk" to a "failure mode". Identifying and managing those risks are particularly difficult when the activities are dispersed geographically and throughout a number of organizations. Reserves are held to allow for some of this. These days, typically, a substantial reserve is held (about 25%) but, all too often, that reserve will have liens placed against it long before the project gets to its preliminary design review. I find that the technical means are available to execute FBC Earth observing missions but all too often the sponsor, swayed by external factors, is unable to meet its commitments for funding and unable to control costs due to a lack of sufficient programmatic insight and an unwillingness to prevent changes in scope in the mission design. These lessons are, of course, broadly applicable. The NASA Earth Sciences Decadal Survey proposes a new, innovative line of missions dubbed "Venture". How that mission line fares under the current budgetary climate and in an environment where all failures seem to be considered to be unacceptable remains to be seen. The lessons NASA learned during the FBC years must be incorporated into the Venture program if NASA is to be able to offer truly innovative, cost-effective, new missions.

Three-year progression of emerald ash borer-induced decline and mortality in southeastern Michigan

Treesearch

Kamal J.K. Gandhi; Annemarie Smith; Robert P. Long; Robin A.J. Taylor; Daniel A. Herms

2008-01-01

We monitored the progression of ash (Fraxinus spp.) decline and mortality due to emerald ash borer (EAB), Agrilus planipennis, in 38 forest stands in the upper Huron River watershed region of southeastern Michigan from 2004-2007. Black ash (F. nigra), green ash (F. pennsylvanica), and white ash...

Genetic transformation of Fraxinus spp. for resistance to the emerald ash borer

Treesearch

Paula M. Pijut; Rochelle R. Beasley; Kaitlin J. Palla

2010-01-01

The emerald ash borer (EAB; Agrilus planipennis Fairmaire) (Coleoptera; Buprestidae) is a wood-boring beetle that poses substantial risk to the ash resource in North America. Ash species native to the United States and known to be susceptible to EAB are Fraxinus pennsylvanica (green ash), F. americana (white ash...

BRAZING ALLOYS

DOEpatents

Donnelly, R.G.; Gilliland, R.G.; Slaughter, G.M.

1963-02-26

A brazing alloy which, in the molten state, is characterized by excellent wettability and flowability, said alloy being capable of forming a corrosion resistant brazed joint wherein at least one component of said joint is graphite and the other component is a corrosion resistant refractory metal, said alloy consisting essentially of 20 to 50 per cent by weight of gold, 20 to 50 per cent by weight of nickel, and 15 to 45 per cent by weight of molybdenum. (AEC)

Wood ash residue causes a mixture of growth promotion and toxicity in Lemna minor.

PubMed

Jagodzinski, Lucas S; O'Donoghue, Marian T; Heffernan, Liam B; van Pelt, Frank N A M; O'Halloran, John; Jansen, Marcel A K

2018-06-01

The use of wood as a sustainable biofuel results in the generation of residual wood ash. The ash contains high amounts of plant macronutrients such as phosphorus, potassium, calcium as well as several micronutrients. To explore the potential use of wood ash as a fertiliser, the growth enhancing properties of Sitka spruce (Picea sitchensis Bong.) wood ash were contrasted with the potential toxic action, using common duckweed (Lemna minor L.) as a model test species. The growth of L. minor exposed to wood bottom and fly ash solids and corresponding leachates was assessed in ultra-oligotrophic and eutrophic media. Ash solids and leachates were also tested as neutralized preparations. Suspended ash solids promoted L. minor growth up to concentrations of 2.5-5g/L. Leachates promoted growth up to 10g ash equivalents per litre, but for bottom ash only. Beneficial effects of wood ash were most pronounced on ultra-oligotrophic medium. However, on such nutrient-deficient medium severe inhibition of L. minor biomass and frond growth was observed at relatively low concentrations of fly ash (EC 50 =14g/L). On standard, eutrophic medium, higher concentrations of fly ash (EC 50 =21g/L), or neutralized fly ash (EC 50 =37g/L) were required to impede growth. Bottom ash, or neutralized bottom ash retarded growth at concentrations of 51g/L and 74g/L (EC 50 ), respectively, in eutrophic medium. It appears that phytotoxicity is due to the elemental composition of the ash, its alkaline character, and possible interactions between these two properties. Growth promotion was due to the substantial content of plant nutrients. This study underlines the importance of the receiving environment (nutrient status and pH) in determining the balance between toxicity and growth promotion, and shows that the margin between growth promoting and toxicity inducing concentrations can be enlarged through ash neutralization. Copyright © 2017 Elsevier B.V. All rights reserved.

Causes of Variability in the Effects of Vegetative Ash on Post-Fire Runoff and Erosion

NASA Astrophysics Data System (ADS)

Balfour, V.; Woods, S.

2008-12-01

Vegetative ash formed during forest wildfires has varying effects on post-fire runoff and erosion. In some cases the ash layer reduces runoff and erosion by storing rainfall and by protecting the soil surface from surface sealing and rainsplash detachment. In other cases, the ash layer increases runoff and erosion by forming a surface crust, clogging soil pores, and providing a ready source of highly erodible fine material. Since only a handful of studies have measured the hydrogeomorphic effect of ash, it is unclear whether the observed variability in its effect reflects initial spatial variability in the ash properties due to factors such as fuel type and fire severity, or differences that develop over time due to compaction and erosion or exposure of the ash to rainfall and air. The goal of our research was to determine if the observed differences in the effect of ash on runoff and erosion are due to: 1) variability in initial ash hydrologic properties due to differences in combustion temperature and fuel type, or 2) variability in ash hydrologic properties caused by mineralogical phase changes that develop after the ash is exposed to water. We created ash in the laboratory using wood and needles of Lodgepole pine (Pinus contorta), Ponderosa pine (Pinus Ponderosa) and Douglas fir (Pseudotsuga menziesii) and at 100° C temperature increments from 300 to 900° C. A subsample of ash from each fuel type / temperature combination was saturated, left undisturbed for 24 hours and then oven dried at 104° C. Dry and wetted ash samples were characterized in terms of: structure (using a scanning electron microscope), carbon content, mineralogy (using X-ray diffraction), porosity, water retention properties and hydraulic conductivity. Ash produced at the higher combustion temperatures from all three fuel types contained lime (CaO), which on wetting was transformed to portlandite (Ca(OH)2) and calcite (CaCO3). This mineralogical transformation resulted in irreversible hardening and crusting of the ash, and hardened ash had a significantly lower hydraulic conductivity than unhardened ash. Ash produced by high severity fires may undergo this same hardening and crusting process after it is wetted by rainfall whereas ash produced by lower severity fires will not, and this may explain in part the contrasting hydrogeomorphic effects of ash that have been reported in the literature.

Evaluation of ash from some tropical plants of Nigeria for the control of Sclerotium rolfsii Sacc. on wheat (Triticum aestivum L.).

PubMed

Enikuomehin, O A; Ikotun, T; Ekpo, E J

1998-01-01

Eleven ash samples, from organs of nine tropical plants, were screened for their abilities to inhibit mycelial growth and sclerotial germination of a Nigerian isolate of Sclerotium rolfsii on agar and in the soil. Ten ash samples showed some activity against mycelial growth of S. rolfsii in vitro. Ash samples from Delonix regia stem wood, Mangifera indica leaf and Vernonia amygdalina leaf were most effective as each totally inhibited mycelial growth of S. rolfsii in vitro. Ocimum gratissimum leaf ash, D. regia wood ash and Musa paradisiaca flower bract ash inhibited sclerotial germination on agar. Nine ash samples protected seeds against pre-emergence rot. Ash from M. indica leaf, V. amygdalina leaf and Azadirachta indica leaf protected seedlings against post-emergence infection. Eichornia crassipes ash, which was ineffective in vitro, offered some protection to seeds in soil against pre-emergence rot. The study demonstrates potentials of ash samples from tropical plants in control of S. rolfsii on wheat.

Development of novel ash hybrids to introgress resistance to emerald ash borer into north American ash species

Treesearch

Jennifer L. Koch; David W. Carey; Mary E. Mason

2008-01-01

Currently, there is no evidence that any of the native North American ash species have any resistance to the emerald ash borer (EAB). This means that the entire ash resource of the eastern United States and Canada is at risk of loss due to EAB. In contrast, outbreaks of EAB in Asian ash species are rare and appear to be isolated responses to stress (Bauer et al. 2005,...

Ash bed level control system for a fixed-bed coal gasifier

DOEpatents

Fasching, George E.; Rotunda, John R.

1984-01-01

An ash level control system is provided which incorporates an ash level meter to automatically control the ash bed level of a coal gasifier at a selected level. The ash level signal from the ash level meter is updated during each cycle that a bed stirrer travels up and down through the extent of the ash bed level. The ash level signal is derived from temperature measurements made by thermocouples carried by the stirrer as it passes through the ash bed and into the fire zone immediately above the ash bed. The level signal is compared with selected threshold level signal to determine if the ash level is above or below the selected level once each stirrer cycle. A first counter is either incremented or decremented accordingly. The registered count of the first counter is preset in a down counter once each cycle and the preset count is counted down at a selected clock rate. A grate drive is activated to rotate a grate assembly supporting the ash bed for a period equal to the count down period to maintain the selected ash bed level. In order to avoid grate binding, the controller provides a short base operating duration time each stirrer cycle. If the ash bed level drops below a selected low level or exceeds a selected high level, means are provided to notify the operator.

Differential utilization of ash phloem by emerald ash borer larvae: Ash species and larval stage effects

Treesearch

Yigen Chen; Michael D. Ulyshen; Therese M. Poland

2012-01-01

Two experiments were performed to determine the extent to which ash species (black, green and white) and larval developmental stage (second, third and fourth instar) affect the efficiency of phloem amino acid utilization by emerald ash borer (EAB) Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) larvae. EAB larvae generally utilized green ash...

Emerald ash borer biocontrol in ash saplings: the potential for early stage recovery of North American ash

USDA-ARS?s Scientific Manuscript database

In many parts of North America, ash stands have been reduced by the emerald ash borer (Agrilus planipennis) invasion to a few surviving mature trees and young basal sprouts, saplings, and seedlings. Without a seed bank, ash tree recovery will require survival and maturation of these younger cohorts...

Ecological and Topographic Features of Volcanic Ash-Influenced Forest Soils

Treesearch

Mark Kimsey; Brian Gardner; Alan Busacca

2007-01-01

Volcanic ash distribution and thickness were determined for a forested region of north-central Idaho. Mean ash thickness and multiple linear regression analyses were used to model the effect of environmental variables on ash thickness. Slope and slope curvature relationships with volcanic ash thickness varied on a local spatial scale across the study area. Ash...

Exploring the molecular and biochemical basis of ash resistance to emerald ash borer

Treesearch

Justin G.A. Whitehill; Daniel A. Herms; Pierluigi Bonello

2010-01-01

Larvae of the emerald ash borer (EAB) (Agrilus planipennis) feed on phloem of ash (Fraxinus spp.) trees. It is hypothesized that the resistance of Asian species of ash (e.g., Manchurian ash, F. mandshurica) to EAB is due to endogenous defenses present in phloem tissues in the form of defensive proteins and/or...

Progression of ash canopy thinning and dieback outward from the initial infestation of emerald ash borer (Coleoptera: Buprestidae) in southeastern Michigan.

PubMed

Smitley, David; Davis, Terrance; Rebek, Eric

2008-10-01

Our objective was to characterize the rate at which ash (Fraxinus spp.) trees decline in areas adjacent to the leading edge of visible ash canopy thinning due to emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae). Trees in southeastern Michigan were surveyed from 2003 to 2006 for canopy thinning and dieback by comparing survey trees with a set of 11 standard photographs. Freeways stemming from Detroit in all directions were used as survey transects. Between 750 and 1,100 trees were surveyed each year. A rapid method of sampling populations of emerald ash borer was developed by counting emerald ash borer emergence holes with binoculars and then felling trees to validate binocular counts. Approximately 25% of the trees surveyed for canopy thinning in 2005 and 2006 also were sampled for emerald ash borer emergence holes using binoculars. Regression analysis indicates that 41-53% of the variation in ash canopy thinning can be explained by the number of emerald ash borer emergence holes per tree. Emerald ash borer emergence holes were found at every site where ash canopy thinning averaged > 40%. In 2003, ash canopy thinning averaged 40% at a distance of 19.3 km from the epicenter of the emerald ash borer infestation in Canton. By 2006, the point at which ash trees averaged 40% canopy thinning had increased to a distance of 51.2 km away from Canton. Therefore, the point at which ash trees averaged 40% canopy thinning, a state of decline clearly visible to the average person, moved outward at a rate of 10.6 km/yr during this period.

Chemical composition and physical properties of filter fly ashes from eight grate-fired biomass combustion plants.

PubMed

Lanzerstorfer, Christof

2015-04-01

For the handling, treatment and utilization of fly ash from biomass combustion its chemical composition and physical properties are important. In this study eight filter fly ashes from different grate-fired biomass combustion plants were investigated. In fly ash from straw combustion high concentrations of (K) were found, whereas in the fly ash from wood combustion the concentrations of Ca and Mg were higher. The average concentration of PO4(3-) was similar in both types of fly ashes. In all wood fly ashes some measured heavy metal concentrations were above the limits for utilization. The straw fly ashes were much less contaminated and can be utilized. For wood fly ash most parameters showed little variation, except from one fly ash where the dust pre-separator is in poor condition. The average values were: mass median diameter 4.3±0.8 μm, spread of particle size distribution 19±11, particle density 2620±80 kg/m3 and angle of repose 50°±1°. The density of the straw fly ashes is lower (2260±80 kg/m3) and the spread of the size distribution is higher (72±24). For one straw combustion fly ash the values of the mass median diameter and the angle of repose were similar to the values of wood combustion fly ash, for the other straw fly ash the values differed considerably. While the particle size of this fly ash was much smaller, surprisingly the angle of repose was also lower. This can be attributed to the formation of small agglomerates in this fly ash, which were not disintegrated without a certain stress. Copyright © 2015. Published by Elsevier B.V.

Basic characteristics of leachate produced by various washing processes for MSWI ashes in Taiwan.

PubMed

Yang, Renbo; Liao, Wing-Ping; Wu, Pin-Han

2012-08-15

Approximately 19.2% of Taiwan's municipal solid waste (MSW) that passes through incineration disposal is converted into ashes (including bottom ash and fly ash). Although bottom ash can pass nearly all of the standards of the toxicity characteristic leaching procedure (TCLP), its high chloride content makes its reuse limited; it generally cannot be used as a fine aggregate material in concrete applications. This research examined washing four types of bottom ash (BA) and fly ash (FA) with water to reduce their chloride content. The optimal water intensity for washing pretreated bottom ash was found to be 7-8L of water per kg of bottom ash, and the optimal water intensity for washing untreated fly ash was found to be 20-25 L of water per kg of fly ash. Based on regression analyses of the chloride concentrations of the leachates and their electrical conductivity (EC) values, each MSW incineration plant has its own ash characteristics as well as a specific regression line in bottom or fly ash leachate. Clearly, it is possible to monitor the EC values of the leachates online by estimation from regression equations to determine the chloride concentrations in the leachates. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

Comparative Effect of Bio-waste Ashes on Strength Properties of Cement Mortar

NASA Astrophysics Data System (ADS)

Ajay, Goyal; Hattori, Kunio; Ogata, Hidehiko; Ashraf, Muhammad; Ahmed, Mohamed Anwar

Biomass fuels produce about 400 million tonnes of ashes as waste material. This paper discusses the pozzolanic character of bio-waste ashes obtained from dry tree leaves (AML), Korai grass (KRI) and Tifton grass (TFT). Ashes were obtained by control incineration of the wastes at 600°C for 5 hours and mortar specimens were prepared by substituting cement with 10, 20 and 30% ash. Strength development of ash-blended mortar specimens was evaluated by conducting destructive tests as well as non-destructive tests till 91 days. X-ray diffraction, scanning electron microscopic and thermo-gravimetric techniques were used to analyze the influence of ash substitution on strength properties of blended-mortar. Pozzolanic reactivity of AML- and KRI-ash was confirmed, but TFT-ash did not show enough reactivity. Overall results confirmed that up to 20% substitution of cement can be made with AML- or KRI-ash with strength approaching 90% of that of control.

Dynamics of surviving ash (Fraxinus spp.) populations in areas long infested by emerald ash borer (Agrilus planipennis)

Treesearch

Kathleen S. Knight; Daniel Herms; Reid Plumb; Eileen Sawyer; Daniel Spalink; Elizabeth Pisarczyk; Bernadette Wiggin; Rachel Kappler; Emily Ziegler; Karen Menard

2012-01-01

Emerald ash borer (EAB) (Agrilus planipennis), an introduced wood-boring insect, has killed millions of ash (Fraxinus spp.) trees in the Midwest region of the United States and Canada. However, in some areas where EAB has caused almost complete mortality of mature ash trees, a small number of healthy ash trees intermingled with...

Host resistance to emerald ash borer: development of novel ash hybrids

Treesearch

Jennifer L. Koch; David W. Carey; Richard Larson

2007-01-01

In contrast to the rapid destruction of ash trees in the United States by emerald ash borer (EAB, Agrilus planipennis Fairmaire), outbreaks of EAB in Asia appear to be isolated responses to stress, such as drought, and do not devastate the ash population. This indicates that in Asia, ash trees may have a level of inherent resistance. This resistance...

Protecting black ash from the emerald ash borer

Treesearch

Les Benedict

2010-01-01

Black ash (Fraxinus nigra) is an important resource for Tribes in the Northeast and Great Lakes regions of the North American continent. Ash in North America is being threatened with widespread destruction as a result of the introduction of emerald ash borer beetle (Agrilus planipennis) in 2002. Measures are being taken to slow the spread of emerald ash borer beetle....

The spatial distribution of riparian ash: implications for the dispersal of the emerald ash borer

Treesearch

Susan J. Crocker; W. Keith Moser; Mark H. Hansen; Mark D. Nelson

2007-01-01

A pilot study to assess riparian ash connectivity and its implications for emerald ash borer dispersal was conducted in three subbasins in Michigan's Southern Lower Peninsula. Forest Inventory and Analysis data were used to estimate ash biomass. The nineteen percent of plots in riparian physiographic classes contained 40 percent of ash biomass. Connectivity of...

Morphology and petrography of volcanic ashes.

NASA Technical Reports Server (NTRS)

Heiken, G.

1972-01-01

Study of volcanic ash samples collected from a variety of recent eruptions using petrography, chemical analyses, and scanning electron microscopy to characterize each type and to relate ash morphology to magma composition and the type of eruption. The ashes are placed in the broad genetic categories of magmatic and phreatomagmatic. The morphology of ash particles from magmatic eruptions of high viscosity magma is governed primarily by vesicle density and shape. Ash particles from eruptions of low viscosity magmas are mostly droplets. The morphology of ash particles from phreatomagmatic eruptions is controlled by stresses within the chilled magma which result in fragmentation of the glass to form small blocky or pyramidal glass ash particles.

The Effects of Bottom Ash on Setting Time and Compressive Strength of Fly Ash Geopolymer Paste

NASA Astrophysics Data System (ADS)

Affandhie, B. A.; Kurniasari, P. T.; Darmawan, M. S.; Subekti, S.; Wibowo, B.; Husin, N. A.; Bayuaji, R.; Irawan, S.

2017-11-01

This research is to find out the contribution of waste energy utilization of fly ash and bottom ash coal as binding agent of geopolymer concrete. This research methodology uses experimental approach in laboratory by making cylinder paste test object with dimension diameter of 2.5 cm x height 5 cm with some combination of fly ash and bottom ash mix with time setting test (ASTM C 191-04a) and compressive strength (ASTM C 39-04a). The research concludes that the effect of bottom ash on fly ash-based geopolymer paste shows good results in setting time and compressive strength.

Study of PCDD/Fs distribution in fly ash, ash deposits, and bottom ash from a medical waste incinerator in China.

PubMed

Du, Yingzhe; Jin, Yuqi; Lu, Shengyong; Peng, Zheng; Li, Xiaodong; Yan, Jianhua

2013-02-01

Over the past decades in China, the number of medical waste incinerators (MWIs) has been rising rapidly, causing emissions of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). In this study, samples of fly ash, ash deposits, and bottom ash from typical MWIs were analyzed for PCDD/Fs and their distribution characteristics. Results showed international toxic equivalent (I-TEQ) values in the range of 6.9-67 ng I-TEQ/g in fly ash and ash deposits, whereas the concentration in bottom ash was extremely low (only 1.33 pg I-TEQ/g), yet the generation of PCDD/Fs was mostly de novo synthesis in fly ash and ash deposits according to the ratio of PCDFs to PCDDs; the major distribution differences of PCDD/Fs in fly ash was manifested by the content of toxic furan 2,3,7,8-TCDF but other toxic PCDD/Fs showed similar distribution. Other findings are that 2,3,4,7,8-PeCDF had the most contribution to TEQ concentration, and that the most abundant toxic furan congener is 1,2,3,4,6,7,8-HpCDF. Correlation analysis showed that there was no significant correlation between PCDD/Fs concentration and several other physical and chemical parameters. This paper is of interest because it presents the emission performances of PCDD/Fs in ash from medical waste incineration in China. PCDD/F contents in fly ash and ash deposits vary between 6.9 and 67.3 ng I-TEQ/g. However, the concentration in bottom ash was extremely low (only 1.33 x 10(-3) ng I-TEQ/g). The fingerprints of PCDD/Fs in fly ash are almost similar, except for 2,3,7,8-TCDF. There is no marked correlation between PCDD/Fs and other physicochemical properties.

Transcriptomic Signatures of Ash (Fraxinus spp.) Phloem

PubMed Central

Mamidala, Praveen; Bonello, Pierluigi; Herms, Daniel A.; Mittapalli, Omprakash

2011-01-01

Background Ash (Fraxinus spp.) is a dominant tree species throughout urban and forested landscapes of North America (NA). The rapid invasion of NA by emerald ash borer (Agrilus planipennis), a wood-boring beetle endemic to Eastern Asia, has resulted in the death of millions of ash trees and threatens billions more. Larvae feed primarily on phloem tissue, which girdles and kills the tree. While NA ash species including black (F. nigra), green (F. pennsylvannica) and white (F. americana) are highly susceptible, the Asian species Manchurian ash (F. mandshurica) is resistant to A. planipennis perhaps due to their co-evolutionary history. Little is known about the molecular genetics of ash. Hence, we undertook a functional genomics approach to identify the repertoire of genes expressed in ash phloem. Methodology and Principal Findings Using 454 pyrosequencing we obtained 58,673 high quality ash sequences from pooled phloem samples of green, white, black, blue and Manchurian ash. Intriguingly, 45% of the deduced proteins were not significantly similar to any sequences in the GenBank non-redundant database. KEGG analysis of the ash sequences revealed a high occurrence of defense related genes. Expression analysis of early regulators potentially involved in plant defense (i.e. transcription factors, calcium dependent protein kinases and a lipoxygenase 3) revealed higher mRNA levels in resistant ash compared to susceptible ash species. Lastly, we predicted a total of 1,272 single nucleotide polymorphisms and 980 microsatellite loci, among which seven microsatellite loci showed polymorphism between different ash species. Conclusions and Significance The current transcriptomic data provide an invaluable resource for understanding the genetic make-up of ash phloem, the target tissue of A. planipennis. These data along with future functional studies could lead to the identification/characterization of defense genes involved in resistance of ash to A. planipennis, and in future ash breeding programs for marker development. PMID:21283712

Research Of The Influence Of Reftinskii SDPP’S Ash On The Processes Of Cement Stone’S Structure Forming

NASA Astrophysics Data System (ADS)

Zimakova, G. A.; Solonina, V. A.; Zelig, M. P.

2017-01-01

The article describes the experimental research of cement stone. Cement stone forming involves highly dispersive mineral additive - ground ash. It is stated that the substitution of some part of cement with activated ash leaves cement strength high. This is possible due to the activity of ash in structure forming processes. Activation of ash provides the increase in its puzzolanic activity, complete hydration processes. it is stated that ash grinding leads to a selective crystallization hydrated neoformations. Their morthology is different on outer and inner surfaces of ash spheres. The usage of ash can provide cement economy on condition that rheological characteristics of concrete stay constant. Besides, the usage of ash will improve physical and mechanic characteristics of cement stone and concrete.

Natural weathering in dry disposed ash dump: Insight from chemical, mineralogical and geochemical analysis of fresh and unsaturated drilled cores.

PubMed

Akinyemi, S A; Akinlua, A; Gitari, W M; Khuse, N; Eze, P; Akinyeye, R O; Petrik, L F

2012-07-15

Some existing alternative applications of coal fly ash such as cement manufacturing; road construction; landfill; and concrete and waste stabilisation use fresh ash directly collected from coal-fired power generating stations. Thus, if the rate of usage continues, the demand for fresh ash for various applications will exceed supply and use of weathered dry disposed ash will become necessary alternative. As a result it's imperative to understand the chemistry and pH behaviour of some metals inherent in dry disposed fly ash. The bulk chemical composition as determined by XRF analysis showed that SiO2, Al2O3 and Fe2O3 were the major oxides in fresh ash and unsaturated weathered ashes. The unsaturated weathered ashes are relatively depleted in CaO, Fe2O3, TiO2, SiO2, Na2O and P2O5 due to dissolution and hydrolysis caused by chemical interaction with ingressing CO2 from the atmosphere and infiltrating rain water. Observed accumulations of Fe2O3, TiO2, CaO, K2O, Na2O and SO3 and Zn, Zr, Sr, Pb, Ni, Cr and Co in the lower layers indicate progressive downward movement through the ash dump though at a slow rate. The bulk mineralogy of unsaturated weathered dry disposed ash, as determined by XRD analysis, revealed quartz and mullite as the major crystalline phases; while anorthite, hematite, enstatite, lime, calcite, and mica were present as minor mineral phases. Pore water chemistry revealed a low concentration of readily soluble metals in unsaturated weathered ashes in comparison with fresh ash, which shows high leachability. This suggests that over time the precipitation of transient minor secondary mineral phases; such as calcite and mica might retard residual metal release from unsaturated weathered ash. Chloride and sulphate species of the water soluble extracts of weathered ash are at equilibrium with Na+ and K+; these demonstrate progressive leaching over time and become supersaturated at the base of unsaturated weathered ash. This suggests that the ash dump does not encapsulate the salt or act as a sustainable salt sink due to over time reduction in pore water pH. The leaching behaviours of Ca, Mg, Na+, K+, Se, Cr and Sr are controlled by the pH of the leachant in both fresh and unsaturated weathered ash. Other trace metals like As, Mo and Pb showed amphoteric behaviour with respect to the pH of the leachant. The precipitation of minor quantities of secondary mineral phases in the unsaturated weathered ash has significant effects on the acid susceptibility and leaching patterns of chemical species in comparison with fresh ash. The unsaturated weathered ash had lower buffering capacity at neutral pH (7.94-8.00) compared to fresh (unweathered) ash. This may be due to the initial high leaching/flushing of soluble basic buffering constituents from fly ash after disposal. The overall results of the acid susceptibility tests suggest that both fresh ash and unsaturated weathered ash would release a large percentage of their chemical species when in contact with slightly acidified rain. Proper management of ash dumps is therefore essential to safeguard the environmental risks of water percolation in different fly ashes behaviour. Copyright © 2012 Elsevier Ltd. All rights reserved.

Deposition and immersion-mode nucleation of ice by three distinct samples of volcanic ash

NASA Astrophysics Data System (ADS)

Schill, G. P.; Genareau, K.; Tolbert, M. A.

2015-07-01

Ice nucleation of volcanic ash controls both ash aggregation and cloud glaciation, which affect atmospheric transport and global climate. Previously, it has been suggested that there is one characteristic ice nucleation efficiency for all volcanic ash, regardless of its composition, when accounting for surface area; however, this claim is derived from data from only two volcanic eruptions. In this work, we have studied the depositional and immersion freezing efficiency of three distinct samples of volcanic ash using Raman microscopy coupled to an environmental cell. Ash from the Fuego (basaltic ash, Guatemala), Soufrière Hills (andesitic ash, Montserrat), and Taupo (Oruanui eruption, rhyolitic ash, New Zealand) volcanoes were chosen to represent different geographical locations and silica content. All ash samples were quantitatively analyzed for both percent crystallinity and mineralogy using X-ray diffraction. In the present study, we find that all three samples of volcanic ash are excellent depositional ice nuclei, nucleating ice from 225 to 235 K at ice saturation ratios of 1.05 ± 0.01, comparable to the mineral dust proxy kaolinite. Since depositional ice nucleation will be more important at colder temperatures, fine volcanic ash may represent a global source of cold-cloud ice nuclei. For immersion freezing relevant to mixed-phase clouds, however, only the Oruanui ash exhibited appreciable heterogeneous ice nucleation activity. Similar to recent studies on mineral dust, we suggest that the mineralogy of volcanic ash may dictate its ice nucleation activity in the immersion mode.

Properties of Controlled Low Strength Material with Circulating Fluidized Bed Combustion Ash and Recycled Aggregates

PubMed Central

Weng, Tsai-Lung; Cheng, An; Chao, Sao-Jeng; Hsu, Hui-Mi

2018-01-01

This study aims to investigate the effect of adding circulating fluidized bed combustion (CFBC) ash, desulfurization slag, air-cooled blast-furnace slag and coal bottom ash to the controlled low-strength material (CLSM). Test methods include slump flow test, ball drop test, water soluble chloride ion content measurement, compressive strength and length change measurement. The results show that (1) the use of CFBC hydration ash with desulfurization slag of slump flow is the best, and the use of CFBC hydration ash with coal bottom ash and slump flow is the worst; (2) CFBC hydration ash with desulfurization slag and chloride ion content is the highest; (3) 24 h ball drop test (diameter ≤ 76 mm), and test results are 70 mm to 76 mm; (4) CFBC hydration ash with desulfurization slag and compression strength is the highest, with the coal bottom ash being the lowest; increase of CFBC hydration ash can reduce compressive strength; and (5) the water-quenched blast furnace slag and CFBC hydration ash would expand, which results in length changes of CLSM specimens. PMID:29724055

Methods to Improve Survival and Growth of Planted Alternative Species Seedlings in Black Ash Ecosystems Threatened by Emerald Ash Borer

Treesearch

Nicholas Bolton; Joseph Shannon; Joshua Davis; Matthew Grinsven; Nam Noh; Shon Schooler; Randall Kolka; Thomas Pypker; Joseph Wagenbrenner

2018-01-01

Emerald ash borer (EAB) continues to spread across North America, infesting native ash trees and changing the forested landscape. Black ash wetland forests are severely affected by EAB. As black ash wetland forests provide integral ecosystem services, alternative approaches to maintain forest cover on the landscape are needed. We implemented simulated EAB infestations...

Growth of larval agrilus planipennis (Coleoptera: Buprestidae) and fitness of tetrastichus planipennisi (Hymenoptera: Eulophidae) in blue ash (Fraxinus quadrangulata) and green ash (F. pennsylvanica)

USDA-ARS?s Scientific Manuscript database

Emerald ash borer (EAB) (Agrilus planipennis) is a primary pest of North American ash (Fraxinus spp.) trees. Blue ash (F. quadrangulata) is more resistant than other North American ash and able to survive EAB infestation. This tree may affect EAB larvae and T. planipennisi. We compared the capacity ...

Investigation of polycyclic aromatic hydrocarbon content in fly ash and bottom ash of biomass incineration plants in relation to the operating temperature and unburned carbon content.

PubMed

Košnář, Zdeněk; Mercl, Filip; Perná, Ivana; Tlustoš, Pavel

2016-09-01

The use of biomass fuels in incineration power plants is increasing worldwide. The produced ashes may pose a serious threat to the environment due to the presence of polycyclic aromatic hydrocarbons (PAHs), because some PAHs are potent carcinogens, mutagens and teratogens. The objective of this study was to investigate the content of total and individual PAHs in fly and bottom ash derived from incineration of phytomass and dendromass, because the data on PAH content in biomass ashes is limited. Various operating temperatures of incineration were examined and the relationship between total PAH content and unburned carbon in ashes was also considered. The analysis of PAHs was carried out in fly and bottom ash samples collected from various biomass incineration plants. PAH determination was performed using gas chromatography coupled with mass spectrometry. The correlations between the low, medium and high molecular weight PAHs and each other in ashes were conducted. The relationship between PAH content and unburned carbon, determined as a loss on ignition (L.O.I.) in biomass ashes, was performed using regression analysis. The PAH content in biomass ashes varied from 41.1±1.8 to 53,800.9±13,818.4ng/g dw. This variation may be explained by the differences in boiler operating conditions and biomass fuel composition. The correlation coefficients for PAHs in ash ranged from 0.8025 to 0.9790. The regression models were designed and the coefficients of determination varied from 0.908 to 0.980. The PAH content in ash varied widely with fuel type and the effect of operating temperature on PAH content in ash was evident. Fly ashes contained higher amounts of PAHs than bottom ashes. The low molecular weight PAHs prevailed in tested ashes. The exponential relationship between the PAH content and L.O.I. for fly ashes and the linear for bottom ashes was observed. Copyright © 2016 Elsevier B.V. All rights reserved.

Structure, properties, and surfactant adsorption behavior of fly ash carbon

NASA Astrophysics Data System (ADS)

Kulaots, Indrek

The objective of this research was to suggest methods by which certain problems associated with use of coal fly ash as a pozzolanic agent in concrete mixtures could be alleviated, guided by a better characterization of fly ash properties. A sample suite of eighty fly ashes was gathered from utilities across the world (mainly US-based) and included ashes from coals ranging in rank from bituminous to lignite. The widely used foam index test is used to characterize ashes with respect to their propensity to adsorb surfactants (called Air Entraining Admixtures or AEAs) used to impart freeze-thaw resistance to concrete. In ash-containing concrete mixtures, AEAs are adsorbed from the polar concrete-water solution onto non-polar unburned carbon surfaces in the ash. The AEA uptake by fly ashes only crudely correlates with the amount of carbon in the fly ash, because carbon surface area, accessibility and polarity all play a role in determining adsorption capacities. Fly ash carbon particle size distribution is also a key factor. Fine carbon particles in fly ash fractions of <106mum are responsible for about 90% of surfactant adsorption capacity. Surfactant adsorption on fly ash carbon is, in the foam index test, a dynamic process. The time of the test (typically <10 minutes) is not long enough to permit penetration of small porosity by the relatively large AEA molecules, and only the most readily available adsorption surface near the geometrical surface of the carbon particles is utilized. The nature of the foam index test was also examined, and it is recommended that a more standardized test procedure based upon pure reagents be adopted for examining the nature of fly ashes. Several possible reagents were identified. Room temperature fly ash ozonation is a powerful technique that allows increasing fly ash surface polarity in a relatively short time and thus is very effective for decreasing the AEA uptake capacity. Depending on the ozone input concentration, sample amount and contact time, surfactant uptake capacity decreases by a factor of two or more following reaction of only 0--1g O3/kg-ash, bringing many ashes into compliance with AEA uptake requirements.

Ranking Coal Ash Materials for Their Potential to Leach Arsenic and Selenium: Relative Importance of Ash Chemistry and Site Biogeochemistry

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

Schwartz, Grace E.; Hower, James C.; Phillips, Allison L.

The chemical composition of coal ash is highly heterogeneous and dependent on the origin of the source coal, combustion parameters, and type and configuration of air pollution control devices. This heterogeneity results in uncertainty in the evaluation of leaching potential of contaminants from coal ash. The goal of this work was to identify whether a single leaching protocol could roughly group high-leaching potential coal ash from low-leaching potential coal ash, with respect to arsenic (As) and selenium (Se). We used four different leaching tests, including the Toxicity Characteristic Leaching Protocol (TCLP), natural pH, aerobic sediment microcosms, and anaerobic sediment microcosmsmore » on 10 different coal ash materials, including fly ash, lime-treated ash, and flue gas desulfurization materials. Leaching tests showed promise in categorizing high and low-leaching potential ash materials, indicating that a single point test could act as a first screening measure to identify high-risk ash materials. However, the amount of contaminant leached varied widely across tests, reflecting the importance of ambient conditions (pH, redox state) on leaching. These results demonstrate that on-site geochemical conditions play a critical role in As and Se mobilization from coal ash, underscoring the need to develop a situation-based risk assessment framework for contamination by coal ash pollutants.« less

Ranking Coal Ash Materials for Their Potential to Leach Arsenic and Selenium: Relative Importance of Ash Chemistry and Site Biogeochemistry

DOE PAGES

Schwartz, Grace E.; Hower, James C.; Phillips, Allison L.; ...

2018-01-23

The chemical composition of coal ash is highly heterogeneous and dependent on the origin of the source coal, combustion parameters, and type and configuration of air pollution control devices. This heterogeneity results in uncertainty in the evaluation of leaching potential of contaminants from coal ash. The goal of this work was to identify whether a single leaching protocol could roughly group high-leaching potential coal ash from low-leaching potential coal ash, with respect to arsenic (As) and selenium (Se). We used four different leaching tests, including the Toxicity Characteristic Leaching Protocol (TCLP), natural pH, aerobic sediment microcosms, and anaerobic sediment microcosmsmore » on 10 different coal ash materials, including fly ash, lime-treated ash, and flue gas desulfurization materials. Leaching tests showed promise in categorizing high and low-leaching potential ash materials, indicating that a single point test could act as a first screening measure to identify high-risk ash materials. However, the amount of contaminant leached varied widely across tests, reflecting the importance of ambient conditions (pH, redox state) on leaching. These results demonstrate that on-site geochemical conditions play a critical role in As and Se mobilization from coal ash, underscoring the need to develop a situation-based risk assessment framework for contamination by coal ash pollutants.« less

Evaluation of Pollutant Leaching Potential of Coal Ashes for Recycling

NASA Astrophysics Data System (ADS)

Park, D.; Woo, N. C.; Kim, H.; Yoon, H.; Chung, D.

2011-12-01

By 2009, coal ashes produced from coal-based power plants in Korea have been reused as cement supplement materials; however, the rest is mostly disposed in landfills inside the plant properties. Continuous production of coal ashes and limited landfill sites require more recycles of coal ashes as base materials, specifically in constructions of roads and of huge industrial complex. Previous researches showed that coal ashes could contain various metals such as arsenic(As), chromium(Cr), lead(Pb), nickel(Ni), selenium(Se), etc. In this study, we collected four types of bottom ashes and two of fly ashes from four coal-based power plants. These ash samples were tested with distilled water through the column leaching process in oxidized conditions. The column test results were compared with those of total digestion, sequential extraction processes and TCLP. Concentrations of metals in outflows from columns are generally greater in fly ashes than in bottom ashes, specifically for As, Se, B, Sr and SO4. Only one fly ash (J2-F) shows high concentrations of arsenic and selenium in leachate. Sequential extraction results indicate that these metals are in readily soluble forms, such as adsorbed, carbonated, and reducible forms. Results of TCLP analysis indicate no potential contaminants leached from the ashes. In conclusion, recycling of coal combustion ashes could be encouraged with proper tests such as sequential and leaching experiments.

Comparison of leaching characteristics of heavy metals from bottom and fly ashes in Korea and Japan.

PubMed

Shim, Young-Sook; Rhee, Seung-Whee; Lee, Woo-Keun

2005-01-01

The objective of this research was to compare the leaching characteristics of heavy metals such as cadmium, chromium, copper, nickel, lead, etc., in Korean and Japanese municipal solid waste incineration (MSWI) ash. The rate of leaching of heavy metal was measured by KSLT and JTL-13, and the amount of heavy metals leached was compared with the metal content in each waste component. Finally, bio-availability testing was performed to assess the risks associated with heavy metals leached from bottom ash and fly ash. From the results, the value of neutralization ability in Japanese fly ash was four times higher than that in Korean fly ash. The reason was the difference in the content of Ca(OH)(2) in fly ash. The amount of lead leached exceeded the regulatory level in both Japanese and Korean fly ash. The rate of leaching was relatively low in ash with a pH in the range of 6-10. The bio-availability test in fly ash demonstrated that the amount of heavy metals leached was Pb>Cd>Cr, but the order was changed to Pb>Cr>Cd in the bottom ash. The leaching concentration of lead exceeded the Japanese risk level in all fly ashes from the two countries, but the leaching concentration of cadmium exceeded the regulatory level in Korean fly ash only.

Sulfidation treatment of molten incineration fly ashes with Na2S for zinc, lead and copper resource recovery.

PubMed

Kuchar, D; Fukuta, T; Onyango, M S; Matsuda, H

2007-04-01

The present study focuses on the conversion of heavy metals involved in molten incineration fly ashes to metal sulfides which could be thereafter separated by flotation. The sulfidation treatment was carried out for five molten incineration fly ashes (Fly ash-A to Fly ash-E) by contacting each fly ash with Na(2)S solution for a period of 10 min to 6h. The initial molar ratio of S(2-) to Me(2+) was adjusted to 1.20. The conversion of heavy metals to metal sulfides was evaluated by measuring the S(2-) residual concentrations using an ion selective electrode. The formation of metal sulfides was studied by XRD and SEM-EDS analyses. In the case of Fly ash-A to Fly ash-D, more than 79% of heavy metals of zinc, lead and copper was converted to metal sulfides within the contacting period of 0.5h owing to a fast conversion of metal chlorides to metal sulfides. By contrast, the conversion of about 35% was achieved for Fly ash-E within the same contacting period, which was attributed to a high content of metal oxides. Further, the S(2-) to Me(2+) molar ratio was reduced to 1.00 to minimize Na(2)S consumption and the conversions obtained within the contacting period of 0.5h varied from 76% for Fly ash-D to 91% for Fly ash-C. Finally, soluble salts such as NaCl and KCl were removed during the sulfidation treatment, which brought about a significant enrichment in metals content by a factor varying from 1.5 for Fly ash-D to 4.9 for Fly ash-A.

The relation between pre-eruptive bubble size distribution, ash particle morphology, and their internal density: Implications to volcanic ash transport and dispersion models

NASA Astrophysics Data System (ADS)

Proussevitch, Alexander

2014-05-01

Parameterization of volcanic ash transport and dispersion (VATD) models strongly depends on particle morphology and their internal properties. Shape of ash particles affects terminal fall velocities (TFV) and, mostly, dispersion. Internal density combined with particle size has a very strong impact on TFV and ultimately on the rate of ash cloud thinning and particle sedimentation on the ground. Unlike other parameters, internal particle density cannot be measured directly because of the micron scale sizes of fine ash particles, but we demonstrate that it varies greatly depending on the particle size. Small simple type ash particles (fragments of bubble walls, 5-20 micron size) do not contain whole large magmatic bubbles inside and their internal density is almost the same as that of volcanic glass matrix. On the other side, the larger compound type ash particles (>40 microns for silicic fine ashes) always contain some bubbles or the whole spectra of bubble size distribution (BSD), i.e. bubbles of all sizes, bringing their internal density down as compared to simple ash. So, density of the larger ash particles is a function of the void fraction inside them (magmatic bubbles) which, in turn, is controlled by BSD. Volcanic ash is a product of the fragmentation of magmatic foam formed by pre-eruptive bubble population and characterized by BSD. The latter can now be measured from bubble imprints on ash particle surfaces using stereo-scanning electron microscopy (SSEM) and BubbleMaker software developed at UNH, or using traditional high-resolution X-Ray tomography. In this work we present the mathematical and statistical formulation for this problem connecting internal ash density with particle size and BSD, and demonstrate how the TFV of the ash population is affected by variation of particle density.

Larval Survival and Growth of Emerald Ash Borer (Coleoptera: Buprestidae) on White Ash and White Fringetree Saplings Under Well-Watered and Water-Deficit Conditions.

PubMed

Rutledge, Claire E; Arango-Velez, Adriana

2017-04-01

Emerald ash borer (Agrilus planipennis Fairmaire) was recently found on a novel host in North America, white fringetree (Chionanthus virginicus L.) (Oleaceae). In this study, we artificially infested 4-yr-old, naïve white fringetree and white ash (Fraxinus americana L.) saplings under well-watered and water-deficit conditions with emerald ash borer eggs. We used physiological and phenotypical approaches to investigate both plant response to emerald ash borer and insect development at 21, 36, and 61 d postinfestation. Photosynthesis was reduced in both tree species by larval feeding, but not by water deficits. Emerald ash borer larvae established and survived successfully on white ash. Both establishment and survival were lower on white fringetree than on white ash. Larvae were larger, and had reached higher instars at all three time points on white ash than on white fringetrees. Larvae grew faster in white ash under water-deficit conditions; however, water-deficit conditions negatively impacted survival of larvae at 61 d postinfestation in white fringetrees, although head size did not differ among surviving larvae. White ash showed higher callus formation in well-watered trees, but no impact on larval survival was observed. In white fringetree, callus formation was not affected by water treatment, and was inversely related to larval survival. The higher rate of mortality and slow growth rate of larvae in white fringetree as compared to white ash suggest that populations of emerald ash borer may be sustained by white fringetree, but may grow more slowly than in white ash. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Controls on the surface chemical reactivity of volcanic ash investigated with probe gases

NASA Astrophysics Data System (ADS)

Maters, Elena C.; Delmelle, Pierre; Rossi, Michel J.; Ayris, Paul M.; Bernard, Alain

2016-09-01

Increasing recognition that volcanic ash emissions can have significant impacts on the natural and human environment calls for a better understanding of ash chemical reactivity as mediated by its surface characteristics. However, previous studies of ash surface properties have relied on techniques that lack the sensitivity required to adequately investigate them. Here we characterise at the molecular monolayer scale the surfaces of ash erupted from Eyjafjallajökull, Tungurahua, Pinatubo and Chaitén volcanoes. Interrogation of the ash with four probe gases, trimethylamine (TMA; N(CH3)3), trifluoroacetic acid (TFA; CF3COOH), hydroxylamine (HA; NH2OH) and ozone (O3), reveals the abundances of acid-base and redox sites on ash surfaces. Measurements on aluminosilicate glass powders, as compositional proxies for the primary constituent of volcanic ash, are also conducted. We attribute the greater proportion of acidic and oxidised sites on ash relative to glass surfaces, evidenced by comparison of TMA/TFA and HA/O3 uptake ratios, in part to ash interaction with volcanic gases and condensates (e.g., H2O, SO2, H2SO4, HCl, HF) during the eruption. The strong influence of ash surface processing in the eruption plume and/or cloud is further supported by particular abundances of oxidised and reduced sites on the ash samples resulting from specific characteristics of their eruptions of origin. Intense interaction with water vapour may result in a higher fraction of oxidised sites on ash produced by phreatomagmatic than by magmatic activity. This study constitutes the first quantification of ash chemical properties at the molecular monolayer scale, and is an important step towards better understanding the factors that govern the role of ash as a chemical agent within atmospheric, terrestrial, aquatic or biotic systems.

On the removal of hexavalent chromium from a Class F fly ash.

PubMed

Huggins, F E; Rezaee, M; Honaker, R Q; Hower, J C

2016-05-01

Coarse and fine samples of a Class F fly ash obtained from commercial combustion of Illinois bituminous coal have been exposed to two long-term leaching tests designed to simulate conditions in waste impoundments. ICP-AES analysis indicated that the coarse and fine fly ash samples contained 135 and 171mg/kg Cr, respectively. Measurements by XAFS spectroscopy showed that the ash samples originally contained 5 and 8% of the chromium, respectively, in the hexavalent oxidation state, Cr(VI). After exposure to water for more than four months, the percentage of chromium as Cr(VI) in the fly-ash decreased significantly for the coarse and fine fly-ash in both tests. Combining the XAFS data with ICP-AES data on the concentration of chromium in the leachates indicated that, after the nineteen-week-long, more aggressive, kinetic test on the coarse fly ash, approximately 60% of the Cr(VI) had been leached, 20% had been reduced to Cr(III) and retained in the ash, and 20% remained as Cr(VI) in the ash. In contrast, during the six-month-long baseline test, very little Cr was actually leached from either the coarse or the fine fly-ash (<0.1mg/kg); rather, about 66% and 20%, respectively, of the original Cr(VI) in the coarse and fine fly-ash was retained in the ash in that form, while the remainder, 34% and 80%, respectively, was reduced and retained in the ash as Cr(III). The results are interpreted as indicating that Cr(VI) present in Class F fly-ash can be reduced to Cr(III) when in contact with water and that such chemical reduction can compete with physical removal of Cr(VI) from the ash by aqueous leaching. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparison of emerald ash borer preference for ash of different species, sun exposure, age, and stress treatments in relation to foliar volatiles and nutrition

Treesearch

Therese M. Poland; Deepa S. Pureswaran; Yigen Chen

2009-01-01

We investigated the host selection behavior and feeding preference of the emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) on six different species of ash including Manchurian ash (F...

Ash content of bones in the pigtail monkey, Macaca nemestrina.

NASA Technical Reports Server (NTRS)

Vose, G. P.; Roach, T. L.

1972-01-01

Ash analyses of skeletons of four adult primates, Macaca nemestrina, revealed some similarities and some marked contrasts when compared with published data on human skeletal ash. The skull in both Macaca nemestrina and man has the highest ash content of all bones in the skeleton. While the bones of the arms of humans have an ash content nearly identical to that of the legs (0.3% difference), in Macaca nemestrina the humeri and radii contain 5.4% more ash than the femora and tibiae. Similarly in Macaca nemestrina the bones of the hands contain 3.5% more ash than the bones of the feet, while in humans the same bones agree within 0.3% implying that adaptive use function is a factor in bone ash concentration. The ribs of Macaca nemestrina showed an unexpectedly high ash content in comparison with those of humans. In contrast with the relatively constant ash content throughout the vertebrae in humans, a conspicuous decrease axially was noted in Macaca nemestrina.

Ash production and dispersal from sustained low-intensity Mono-Inyo eruptions

NASA Astrophysics Data System (ADS)

Black, Benjamin A.; Manga, Michael; Andrews, Benjamin

2016-08-01

Recent rhyolitic volcanism has demonstrated that prolonged low-intensity ash venting may accompany effusive dome formation. We examine the possibility and some consequences of episodes of extended, weak ash venting at the rhyolitic Mono-Inyo chain in Eastern California. We describe ash-filled cracks within one of the youngest domes, Panum Crater, which provide a textural record of ash venting during dome effusion. We use synchrotron-based X-ray computed tomography to characterize the particles in these tuffisites. Particle sizes in well-sorted tuffisite layers agree well with grain size distributions observed during weak ash venting at Soufrière Hills Volcano, Montserrat, and yield approximate upper and lower bounds on gas velocity and mass flux during the formation of those layers. We simulate ash dispersal with Ash3d to assess the consequences of long-lived Mono-Inyo ash venting for ash deposition and the accompanying volcanic hazards. Our results highlight the sensitivity of large-scale outcomes of volcanic eruptions to small-scale processes.

Study on cement mortar and concrete made with sewage sludge ash.

PubMed

Chang, F C; Lin, J D; Tsai, C C; Wang, K S

2010-01-01

This study investigated the feasibility of reusing wastewater sludge ash in construction materials to replace partial materials. Wastewater sludge sampled from thermal power plant was burned into sludge ash at 800°C in the laboratory. The sludge incineration ash has low heavy metal including Pb, Cd, Cr and Cu, so it belongs to general enterprise waste. The chemical composition of sludge incineration ash was summed up in SiO₂, CaO, Fe₂O₃ and MgO. Then the wastewater sludge ash is also found to be a porous material with irregular surface. When the sludge ash was used to replace mortar or concrete cement, its water-adsorption capability will result in the reduction of mortar workability and compressive strength. Cement is being substituted for sludge ash, and 10 percent of sludge ash is more appropriate. Sludge ash is reused to take the place of construction materials and satisfies the requests of standard specification except for higher water absorption.

Review of ecosystem level impacts of emerald ash borer on black ash wetlands: What does the future hold?

Treesearch

Randall K. Kolka; Anthony W. D' Amato; Joseph W. Wagenbrenner; Robert A. Slesak; Thomas G. Pypker; Melissa B. Youngquist; Alexis R. Grinde; Brian J. Palik

2018-01-01

The emerald ash borer (EAB) is rapidly spreading throughout eastern North America and devastating ecosystems where ash is a component tree. This rapid and sustained loss of ash trees has already resulted in ecological impacts on both terrestrial and aquatic ecosystems and is projected to be even more severe as EAB invades black ash-dominated wetlands of the western...

Chemical ecology and behavioral studies on the emerald ash borer: an update

Treesearch

Deepa Pureswaran; Therese Poland

2008-01-01

In 2006, we tested host selection and feeding preference of the emerald ash borer (EAB) on four species of ash species (green, black, white, and blue ash) that are native to North America but exotic to the beetle. For comparison, we also included Manchurian ash (which is native to the beetle) and European ash (which is exotic to the beetle) in the test. Beetles were...

Leaching characteristics of arsenic and selenium from coal fly ash: role of calcium

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

Tian Wang; Jianmin Wang; Yulin Tang

2009-05-15

Understanding the leaching behavior of arsenic (As) and selenium (Se) in coal fly ash is important in evaluating the potential environmental impact of coal fly ash. Batch experiments were employed to systematically investigate the leaching behavior of As and Se in two major types of coal fly ashes, bituminous coal ash and sub-bituminous coal ash, and to determine the underlying processes that control As and Se leaching. The effects of pH, solid/liquid (S/L) ratio, calcium addition, and leaching time on the release of As and Se were studied. Overall, bituminous coal ash leached significantly more As and Se than sub-bituminousmore » coal ash, and Se was more readily leachable, in both absolute concentration and relative fraction, than As for both types of fly ashes. Adsorption/desorption played a major role on As and Se leaching from bituminous coal ashes. However, calcium precipitation played the most important role in reducing As and Se leaching from sub-bituminous coal ashes in the entire experimental pH range. The leaching of As and Se from bituminous coal ashes generally increased with increases in the S/L ratio and leaching time. However, for sub-bituminous coal ashes, the leaching of As was not detected under most experimental conditions, while the leaching of Se increased with increases in the S/L ratio and leaching time. As{sup V} and Se{sup IV} were found to be the major species in all ash leachates in this study. 46 refs., 7 figs., 1 tab.« less

Molecular recognition of emerald ash borer infestation using leaf spray mass spectrometry.

PubMed

Falcone, Caitlin E; Cooks, R Graham

2016-06-15

The introduction of the emerald ash borer (Agrilus planipennis) (EAB) from Asia to Michigan, USA, in the 1990s caused the widespread death of ash trees in two Canadian provinces and 24 US states. The three current methods for the detection of emerald ash borer infestation, visual surveys, tree girdling and artificial traps, can be unreliable, and there is clearly a need for a rapid, dependable technique for the detection of emerald ash borer infestation. Leaf spray, an ambient ionization method for mass spectrometry (MS), gives direct chemical information on a leaf sample by applying a high voltage to a naturally or artificially sharply pointed leaf piece causing ions to be generated directly from the leaf tip for MS analysis. Leaflets from 23 healthy and EAB-infested ash trees were analyzed by leaf spray mass spectrometry in an attempt to distinguish healthy and EAB-infested ash trees. In negative ion mode, healthy ash trees showed an increased abundance of ions m/z 455.5, 471.5 and 487.5, and ash trees infested with the EAB displayed an increased abundance of ions m/z 181 and 217. The identities of the chemical discriminators ursolic acid and oleanolic acid in healthy ash trees, and six-carbon sugar alcohols in infested ash trees, were determined by tandem mass spectrometry and confirmed with standards. This preliminary study suggests that leaf spray mass spectrometry of ash tree leaflets provides a potential tool for the early detection of ash tree infestation by the emerald ash borer. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Thermal co-treatment of combustible hazardous waste and waste incineration fly ash in a rotary kiln.

PubMed

Huber, Florian; Blasenbauer, Dominik; Mallow, Ole; Lederer, Jakob; Winter, Franz; Fellner, Johann

2016-12-01

As current disposal practices for municipal solid waste incineration (MSWI) fly ash are either associated with significant costs or negative environmental impacts, an alternative treatment was investigated in a field scale experiment. Thereto, two rotary kilns were fed with hazardous waste, and moistened MSWI fly ash (water content of 23%) was added to the fuel of one kiln with a ratio of 169kg/Mg hazardous waste for 54h and 300kg/Mg hazardous waste for 48h while the other kiln was used as a reference. It was shown that the vast majority (>90%) of the inserted MSWI fly ash was transferred to the bottom ash of the rotary kiln. This bottom ash complied with the legal limits for non-hazardous waste landfills, thereby demonstrating the potential of the investigated method to transfer hazardous waste (MSWI fly ash) into non-hazardous waste (bottom ash). The results of a simple mixing test (MSWI fly ash and rotary kiln bottom ash have been mixed accordingly without thermal treatment) revealed that the observed transformation of hazardous MSWI fly ash into non-hazardous bottom ash during thermal co-treatment cannot be referred to dilution, as the mixture did not comply with legal limits for non-hazardous waste landfills. For the newly generated fly ash of the kiln, an increase in the concentration of Cd, K and Pb by 54%, 57% and 22%, respectively, was observed. In general, the operation of the rotary kiln was not impaired by the MSWI fly ash addition. Copyright © 2016 Elsevier Ltd. All rights reserved.

Studies of Transitional Flow, Unsteady Separation Phenomena and Particle Induced Augmentation Heating on Ablated Nose Tips.

DTIC Science & Technology

1975-10-01

63 29 Variation of Profile Shape with Time for Axisyinmetric Camphor Models 63 30 The Development of Ablated Nose Shapes Over Which Flow...ablation tests using camphor models and inferred from downrange observation of full scale flight missions. Regions of gross instability on nose...been verified in wind tunnel tests of camphor models where shapes similar to those shown on Figure 29 can be developed under transitional conditions

Liquid coated melt-spun Nd-Fe-B powders for bonded magnets

NASA Astrophysics Data System (ADS)

Li, D.; Gaiffi, S.; Kirk, D.; Young, K.; Herchenroeder, J.; Berwald, T.

1999-04-01

The liquid coating (LC) has been employed to apply epoxy and lubricant over the surface of rapidly solidified Nd-Fe-B powder particles. The LC led to an improvement of physical and magnetic properties for the powders and magnets compared to the dry blending and the encapsulation methods. The LC powders have excellent flowability and can be used for bonded magnets requiring very close tolerances; further bonded magnets made using this powder posses higher strength.

Effect of different drying techniques on flowability characteristics and chemical properties of natural carbohydrate-protein Gum from durian fruit seed

PubMed Central

2013-01-01

Background A natural carbohydrate biopolymer was extracted from the agricultural biomass waste (durian seed). Subsequently, the crude biopolymer was purified by using the saturated barium hydroxide to minimize the impurities. Finally, the effect of different drying techniques on the flow characteristics and functional properties of the purified biopolymer was investigated. The present study elucidated the main functional characteristics such as flow characteristics, water- and oil-holding capacity, solubility, and foaming capacity. Results In most cases except for oven drying, the bulk density decreased, thus increasing the porosity. This might be attributed to the increase in the inter-particle voids of smaller sized particles with larger contact surface areas per unit volume. The current study revealed that oven-dried gum and freeze-dried gum had the highest and lowest compressibility index, thus indicating the weakest and strongest flowability among all samples. In the present work, the freeze-dried gum showed the lowest angle of repose, bulk, tapped and true density. This indicates the highest porosity degree of freeze dried gum among dried seed gums. It also exhibited the highest solubility, and foaming capacity thus providing the most desirable functional properties and flow characteristics among all drying techniques. Conclusion The present study revealed that freeze drying among all drying techniques provided the most desirable functional properties and flow characteristics for durian seed gum. PMID:23289739

Influence of etching time and bonding strategies on the microshear bond strength of self- and light-cured pit-and-fissure sealants.

PubMed

Souza-Junior, Eduardo José; Borges, Boniek Castillo Dutra; Montes, Marcos Antônio Japiassú Resende; Alonso, Roberta Caroline Bruschi; Ambrosano, Glaucia Maria Bovi; Sinhoreti, Mário Alexandre Coelho

2012-01-01

This study evaluated the impact of extended etching and bonding strategies on the microshear bond strength of three sealant materials. Two pit-and-fissure sealants [FluroShield, Dentsply (light-cured) and AlphaSeal, DFL (self-cured)] and one light-cured flowable composite resin (Permaflo, Ultradent) were evaluated according to different enamel etching times (15 s or 30 s) and bonding procedures (no adhesive application, application of primer/hydrophobic resin or hydrophobic resin only). Intact enamel blocks were obtained from bovine teeth and sealed via the tested protocols. After 24 h, the microshear bond strength test was performed in a universal testing machine at a crosshead speed of 0.5 mm/min. Failure modes were classified by stereomicroscopy. Data were submitted to a three-way ANOVA and to Tukey's test (α=0.05). There was no statistically significant difference (p>0.05) among the materials. Permaflo showed higher bond strength when etched for 30 s alone. Enamel overetching decreased the bond strength of the light-cured sealant. Primer/bond previous treatment improved bond performance for AlphaSeal. In conclusion, from the tested conditions, all sealant materials presented similar bond strength values in relation to bonding protocol and etching time. The flowable composite can be used as a pit-and-fissure sealant. The use of a three-step adhesive system was essential for the self-cured sealant application.

Surface topography of composite restorative materials following ultrasonic scaling and its Impact on bacterial plaque accumulation. An in-vitro SEM study.

PubMed

Hossam, A Eid; Rafi, A Togoo; Ahmed, A Saleh; Sumanth, Phani Cr

2013-06-01

This is an in vitro study to investigate the effects of ultrasonic scaling on the surface roughness and quantitative bacterial count on four different types of commonly used composite restorative materials for class V cavities. Nanofilled, hybrid, silorane and flowable composites were tested. Forty extracted teeth served as specimen and were divided into 4 groups of 10 specimens, with each group receiving a different treatment and were examined by a Field emission scanning electron microscope. Bacterial suspension was then added to the pellicle-coated specimens, and then bacterial adhesion was analyzed by using image analyzing program. Flowable and silorane-based composites showed considerably smoother surfaces and lesser bacterial count in comparison to other types, proving that bacterial adhesion is directly proportional to surface roughness. The use of ultrasonic scalers affects the surfaces of composite restorative materials. Routine periodontal scaling should be carried out very carefully, and polishing of the scaled surfaces may overcome the alterations in roughness, thus preventing secondary caries, surface staining, plaque accumulation and subsequent periodontal inflammation. How to cite this article: Eid H A, Togoo R A, Saleh A A, Sumanth C R. Surface Topography of Composite Restorative Materials following Ultrasonic Scaling and its Impact on Bacterial Plaque Accumulation. An In-Vitro SEM Study. J Int Oral Health 2013; 5(3):13-19.

Surface topography of composite restorative materials following ultrasonic scaling and its Impact on bacterial plaque accumulation. An in-vitro SEM study

PubMed Central

Hossam, A. Eid; Rafi, A. Togoo; Ahmed, A Saleh; Sumanth, Phani CR

2013-01-01

Background: This is an in vitro study to investigate the effects of ultrasonic scaling on the surface roughness and quantitative bacterial count on four different types of commonly used composite restorative materials for class V cavities. Materials & Methods: Nanofilled, hybrid, silorane and flowable composites were tested. Forty extracted teeth served as specimen and were divided into 4 groups of 10 specimens, with each group receiving a different treatment and were examined by a Field emission scanning electron microscope. Bacterial suspension was then added to the pellicle-coated specimens, and then bacterial adhesion was analyzed by using image analyzing program. Results: Flowable and silorane-based composites showed considerably smoother surfaces and lesser bacterial count in comparison to other types, proving that bacterial adhesion is directly proportional to surface roughness. Conclusion: The use of ultrasonic scalers affects the surfaces of composite restorative materials. Routine periodontal scaling should be carried out very carefully, and polishing of the scaled surfaces may overcome the alterations in roughness, thus preventing secondary caries, surface staining, plaque accumulation and subsequent periodontal inflammation. How to cite this article: Eid H A, Togoo R A, Saleh A A, Sumanth C R. Surface Topography of Composite Restorative Materials following Ultrasonic Scaling and its Impact on Bacterial Plaque Accumulation. An In-Vitro SEM Study. J Int Oral Health 2013; 5(3):13-19. PMID:24155597

Failure Rates of Orthodontic Fixed Lingual Retainers bonded with Two Flowable Light-cured Adhesives: A Comparative Prospective Clinical Trial.

PubMed

Talic, Nabeel F

2016-08-01

This comparative prospective randomized clinical trial examined the in vivo failure rates of fixed mandibular and maxillary lingual retainers bonded with two light-cured flowable composites over 6 months. Consecutive patients were divided into two groups on a 1:1 basis. Two hundred fixed lingual retainers were included, and their failures were followed for 6 months. One group (n = 50) received retainers bonded with a nano-hybrid composite based on nano-optimized technology (Tetric-N-Flow, Ivoclar Vivadent). Another group (n = 50) received retainers bonded with a low viscosity (LV) composite (Transbond Supreme LV, 3M Unitek). There was no significant difference between the overall failure rates of mandibular retainers bonded with Transbond (8%) and those bonded with Tetric-N-Flow (18%). However, the odds ratio for failure using Tetric-N-flow was 2.52-fold greater than that of Transbond. The failure rate of maxillary retainers bonded with Transbond was higher (14%), but not significantly different, than that of maxillary retainers bonded with Tetric-N-flow (10%). There was no significant difference in the estimated mean survival times of the maxillary and mandibular retainers bonded with the two composites. Both types of composites tested in the current study can be used to bond fixed maxillary and mandibular lingual retainers, with low failure rates.

Intraorifice sealing ability of different materials in endodontically treated teeth: An in vitro study.

PubMed

Parekh, Bandish; Irani, Rukshin S; Sathe, Sucheta; Hegde, Vivek

2014-05-01

Microbial contamination of the pulp space is one of the major factors associated with endodontic failure. Thus, in addition to a three dimentional apical filling a coronal seal for root canal fillings has been recommended. The present study was conducted to evaluate and compare the intra-orifice sealing ability of three experimental materials after obturation of the root canal system. Fourty single rooted mandibular premolars were decoronated, cleaned, shaped and obturated. Gutta-percha was removed to the depth of 3.5 mm from the orifice with a heated plugger. Ten specimens each were sealed with Light Cure Glass Ionomer Cement (LCGIC), Flowable Composite (Tetric N-Flow), and Light Cure Glass Ionomer Cement with Flowable Composite in Sandwich Technique along with a positive control respectively and roots submerged in Rhodamine-B dye in vacuum for one week. Specimens were longitudinally sectioned and leakage measured using a 10X stereomicroscope and graded for depth of leakage. According to the results of the present study LC GIC + Tetric N Flow demonstrated significantly better seal (P < 0.01) than LC GIC. However there was no statistically significant difference in leakage (P > 0.01) between Tetric N-Flow and LCGIC+Tetric N-Flow groups. In the current study LCGIC+Tetric N-Flow was found to be superior over other experimental materials as intra-orifice barriers.

Study on the RF inductively coupled plasma spheroidization of refractory W and W-Ta alloy powders

NASA Astrophysics Data System (ADS)

Chenfan, YU; Xin, ZHOU; Dianzheng, WANG; Neuyen VAN, LINH; Wei, LIU

2018-01-01

Spherical powders with good flowability and high stacking density are mandatory for powder bed additive manufacturing. Nevertheless, the preparation of spherical refractory tungsten and tungsten alloy powders is a formidable task. In this paper, spherical refractory metal powders processed by high-energy stir ball milling and RF inductively coupled plasma were investigated. By utilizing the technical route, pure spherical tungsten powders were prepared successfully, the flowability increased from 10.7 s/50 g to 5.5 s/50 g and apparent density increased from 6.916 g cm-3 to 11.041 g cm-3. Alloying element tantalum can reduce the tendency to micro-crack during tungsten laser melting and rapid solidification process. Spherical W-6Ta (%wt) powders were prepared in this way, homogeneous dispersion of tantalum in a tungsten matrix occurred but a small amount of flake-like shape particles appeared after high-energy stir ball milling. The flake-like shape particles can hardly be spheroidized in subsequent RF inductively coupled plasma process, might result from the unique suspended state of flaky particles under complex electric and magnetic fields as well as plasma-particle heat exchange was different under various turbulence models. As a result, the flake-like shape particles cannot pass through the high-temperature area of thermal plasma torch and cannot be spheroidized properly.

[Comparative study of polymerization shrinkage and related properties of flowable composites and an unfilled resin].

PubMed

Bukovinszky, Katalin; Molnár, Lilla; Bakó, József; Szalóki, Melinda; Hegedus, Csaba

2014-03-01

The polymerization shrinkage and shrinkage stress of dental composites are in the center of the interest of researchers and manufacturers. It is a great challenge to minimize this important property as low as possible. Many factors are related and are in complicated correlation with each other affecting the polymerization shrinkage. Polymerization shrinkage stress degree of conversion and elasticity has high importance from this aspect. Our aim was to study the polymerization shrinkage and related properties (modulus of elasticity, degree of conversion, shrinkage stress) of three flowable composite (Charisma Opal Flow, SDR, Filtek Ultimate) and an unfilled composite resin. Modulus of elasticity was measured using three point flexure tests on universal testing machine. The polymerization shrinkage stress was determined using bonded-disc technique. The degree of conversion measurements were performed by FT-IR spectroscopy. And the volumetric shrinkage was investigated using Archimedes principle and was measured on analytical balance with special additional equipment. The unfilled resin generally showed higher shrinkage (8,26%), shrinkage stress (0,8 MPa) and degree of conversion (38%), and presented the lowest modulus of elasticity (3047,02MPa). Highest values of unfilled resin correspond to the literature. The lack of fillers enlarges the shrinkage, and the shrinkage stress, but gives the higher flexibility and higher degree of conversion. Further investigations needs to be done to understand and reveal the differences between the composites.

Effect of Ingested Liquids on Color Change of Composite Resins.

PubMed

Malek Afzali, Beheshteh; Ghasemi, Amir; Mirani, Asrin; Abdolazimi, Zahra; Akbarzade Baghban, Alireza; Kharazifard, Mohammad Javad

2015-08-01

Color change of composite restorations is well known to dentists. However, the effect of commonly consumed drinks on discoloration of composite resins has yet to be determined. This study sought to assess the color change of a nanofilled (Premise) and a flowable composite resin (Premise flowable) following simulated consumption of tea, cola, iron drops and multivitamin syrup. Forty disk-shaped specimens (7 mm in diameter and 2 mm thick) were fabricated from each composite resin. The baseline color values were measured according to the CIE L*a*b* system using digital imaging. The specimens of each restorative material were randomly divided into five groups (eight each) according to the storage media namely tea, cola, iron drops, multivitamin syrup or distilled water (control). The specimens were immersed in staining solutions for three hours daily over a 40-day test period. Following this, the color change values (ΔE*) were calculated. For statistical analyses, the color differences were analyzed using two-way ANOVA and Tukey's test (P< 0.05). There was no significant difference in ΔE* values between the two types of composite resins (P>0.05). In both composite materials, the difference among the solutions was not significant (P>0.05). Under the tested experimental conditions, both restorative materials were susceptible to discoloration by all four staining solutions. The color change values were not related to the solution or the type of material used.

Influence of different types of low substituted hydroxypropyl cellulose on tableting, disintegration, and floating behaviour of floating drug delivery systems

PubMed Central

Diós, Péter; Pernecker, Tivadar; Nagy, Sándor; Pál, Szilárd; Dévay, Attila

2014-01-01

The object of the present study is to evaluate the effect of application of low-substituted hydroxypropyl cellulose (L-HPC) 11 and B1 as excipients promoting floating in gastroretentive tablets. Directly compressed tablets were formed based on experimental design. Face-centred central composite design was applied with two factors and 3 levels, where amount of sodium alginate (X1) and L-HPC (X2) were the numerical factors. Applied types of L-HPCs and their 1:1 mixture were included in a categorical factor (X3). Studied parameters were floating lag time, floating time, floating force, swelling behaviour of tablets and dissolution of paracetamol, which was used as a model active substance. Due to their physical character, L-HPCs had different water uptake and flowability. Lower flowability and lower water uptake was observed after 60 min at L-HPC 11 compared to L-HPC B1. Shorter floating times were detected at L-HPC 11 and L-HPC mixtures with 0.5% content of sodium alginate, whereas alginate was the only significant factor. Evaluating results of drug release and swelling studies on floating tablets revealed correlation, which can serve to help to understand the mechanism of action of L-HPCs in the field development of gastroretentive dosage forms. PMID:26702261

Feasibility study of a soil-based rubberized CLSM.

PubMed

Wu, Jason Y; Tsai, Mufan

2009-02-01

The development of beneficial uses of recycled scrap tires is always in great demand around the world. The disposal of on-site surplus excavated soil and the production of standard engineering aggregates have also been facing increasing environmental and ecological challenges in congested islands, such as Taiwan. This paper presents an experimental study using recycled crumb rubber and native silty sand to produce a lightweight, soil-based, rubberized controlled low strength material (CLSM) for a bridge approach repair. To assess the technical feasibility of this material, the effects of weight ratios of cement-to-water (C/W) and water-to-solid (W/S), and of rubber content on the engineering properties for different mixtures were investigated. The presented test results include flowability, unit weight, strength, settlement potential, and bearing capacity. Based on the findings, we conclude that a soil-based rubberized CLSM with 40% sand by weight and an optimal design ratio of 0.7 for C/W and 0.35 for W/S can be used for the proposed bridge approach repair. Such a mixture has demonstrated acceptable flowability, strength, and bearing capacity. Its lower unit weight, negligible compressibility, and hydrocollapse potential also help ensure that detrimental settlement is unlikely to occur. The results illustrate a novel scheme of CLSM production, and suggest a beneficial alternative for the reduction of scrap tires as well as conservation of resources and environment.

Photobiomodulation of a flowable matrix in a human skin ex vivo model demonstrates energy-based enhancement of engraftment integration and remodeling.

PubMed

Neves, Lia M G; Parizotto, Nivaldo A; Cominetti, Marcia R; Bayat, Ardeshir

2018-04-24

The use of dermal substitutes to treat skin defects such as ulcers has shown promising results, suggesting a potential role for skin substitutes for treating acute and chronic wounds. One of the main drawbacks with the use of dermal substitutes is the length of time from engraftment to graft take, plus the risk of contamination and failure due to this prolonged integration. Therefore, the use of adjuvant energy-based therapeutic modalities to augment and accelerate the rate of biointegration by dermal substitute engraftments is a desirable outcome. The photobiomodulation (PBM) therapy modulates the repair process, by stimulating cellular proliferation and angiogenesis. Here, we evaluated the effect of PBM on a collagen-glycosaminoglycan flowable wound matrix (FWM) in an ex vivo human skin wound model. PBM resulted in accelerated rate of re-epithelialization and organization of matrix as seen by structural arrangement of collagen fibers, and a subsequent increased expression of alpha-smooth muscle actin (α-SMA) and vascular endothelial growth factor A (VEGF-A) leading to an overall improved healing process. The use of PBM promoted a beneficial effect on the rate of integration and healing of FWM. We therefore propose that the adjuvant use of PBM may have utility in enhancing engraftment and tissue repair and be of value in clinical practice. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Preparation and evaluation of highly drug-loaded fine globular granules using a multi-functional rotor processor.

PubMed

Iwao, Yasunori; Kimura, Shin-Ichiro; Ishida, Masayuki; Mise, Ryohei; Yamada, Masaki; Namiki, Noriyuki; Noguchi, Shuji; Itai, Shigeru

2015-01-01

The manufacture of highly drug-loaded fine globular granules eventually applied for orally disintegrating tablets has been investigated using a unique multi-functional rotor processor with acetaminophen, which was used as a model drug substance. Experimental design and statistical analysis were used to evaluate potential relationships between three key operating parameters (i.e., the binder flow rate, atomization pressure and rotating speed) and a series of associated micromeritics (i.e., granule mean size, proportion of fine particles (106-212 µm), flowability, roundness and water content). The results of multiple linear regression analysis revealed several trends, including (1) the binder flow rate and atomization pressure had significant positive and negative effects on the granule mean size value, Carr's flowability index, granular roundness and water content, respectively; (2) the proportion of fine particles was positively affected by the product of interaction between the binder flow rate and atomization pressure; and (3) the granular roundness was negatively and positively affected by the product of interactions between the binder flow rate and the atomization pressure, and the binder flow rate and rotating speed, respectively. The results of this study led to the identification of optimal operating conditions for the preparation of granules, and could therefore be used to provide important information for the development of processes for the manufacture of highly drug-loaded fine globular granules.

Properties and Leachability of Self-Compacting Concrete Incorporated with Fly Ash and Bottom Ash

NASA Astrophysics Data System (ADS)

Kadir, Aeslina Abdul; Ikhmal Haqeem Hassan, Mohd; Jamaluddin, Norwati; Bakri Abdullah, Mohd Mustafa Al

2016-06-01

The process of combustion in coal-fired power plant generates ashes, namely fly ash and bottom ash. Besides, coal ash produced from coal combustion contains heavy metals within their compositions. These metals are toxic to the environment as well as to human health. Fortunately, treatment methods are available for these ashes, and the use of fly ash and bottom ash in the concrete mix is one of the few. Therefore, an experimental program was carried out to study the properties and determine the leachability of selfcompacting concrete incorporated with fly ash and bottom ash. For experimental study, self-compacting concrete was produced with fly ash as a replacement for Ordinary Portland Cement and bottom ash as a replacement for sand with the ratios of 10%, 20%, and 30% respectively. The fresh properties tests conducted were slump flow, t500, sieve segregation and J-ring. Meanwhile for the hardened properties, density, compressive strength and water absorption test were performed. The samples were then crushed to be extracted using Toxicity Characteristic Leaching Procedure and heavy metals content within the samples were identified accordingly using Atomic Absorption Spectrometry. The results demonstrated that both fresh and hardened properties were qualified to categorize as self-compacting concrete. Improvements in compressive strength were observed, and densities for all the samples were identified as a normal weight concrete with ranges between 2000 kg/m3 to 2600 kg/m3. Other than that, it was found that incorporation up to 30% of the ashes was safe as the leached heavy metals concentration did not exceed the regulatory levels, except for arsenic. In conclusion, this study will serve as a reference which suggests that fly ash and bottom ash are widely applicable in concrete technology, and its incorporation in self-compacting concrete constitutes a potential means of adding value to appropriate mix and design.

Bubbles and Dust: Dissolution Rates of Unhydrated Volcanic Ash as a Function of Morphology, Composition, and Particle Size

NASA Astrophysics Data System (ADS)

Wygel, C. M.; Sahagian, D. L.

2017-12-01

Volcanic eruptions are natural hazards due to their explosive nature and widespread transportation and deposition of ash particles. After deposition and subsequent leaching in soils or water bodies, ash deposition positively (nutrients) and negatively (contaminants) impacts the health of flora and fauna, including humans. The effects of ash leachates have been difficult to replicate in field and laboratory studies due to the many complexities and differences between ash particles. Ash morphology is characteristic for each eruption, dependent upon eruption energy, and should play a critical role in determining leaching rates. Morphology reflects overall particle surface area, which is strongly influenced by the presence of surface dust. In addition, ash composition, which in part controls morphology and particle size, may also affect leaching rates. This study determines the extent to which ash morphology, surface area, composition, and particle size control ash dissolution rates. Further, it is necessary to determine whether compound vesicular ash particles permit water into their interior structures to understand if both the internal and external surface areas are available for leaching. To address this, six fresh, unhydrated ash samples from diverse volcanic environments and a large range in morphology, from Pele's spheres to vesicular compound ash, are tested in the laboratory. Ash morphology was characterized on the Scanning Electron Microscope (SEM) before and after leaching and surface area was quantified by Brunauer Emmett Teller (BET) analysis and with geometric calculations. Column Leachate Tests (CLT) were conducted to compare leaching rates over a range of basaltic to silicic ashes as a function of time and surface area, to recreate the effects of ash deposition in diverse volcanic environments. After the CLT, post-leaching water analyses were conducted by Ion Coupled Plasma-Mass Spectrometry (ICP-MS) and Ion Chromatography (IC). We find that leaching rates are correlated to characteristic surface area of ash particles.

Physiological responses of emerald ash borer larvae to feeding on different ash species reveal putative resistance mechanisms and insect counter-adaptations.

PubMed

Rigsby, C M; Showalter, D N; Herms, D A; Koch, J L; Bonello, P; Cipollini, D

2015-07-01

Emerald ash borer, Agrilus planipennis Fairmaire, an Asian wood-boring beetle, has devastated ash (Fraxinus spp.) trees in North American forests and landscapes since its discovery there in 2002. In this study, we collected living larvae from EAB-resistant Manchurian ash (Fraxinus mandschurica), and susceptible white (Fraxinus americana) and green (Fraxinus pennsylvanica) ash hosts, and quantified the activity and production of selected detoxification, digestive, and antioxidant enzymes. We hypothesized that differences in larval physiology could be used to infer resistance mechanisms of ash. We found no differences in cytochrome P450, glutathione-S-transferase, carboxylesterase, sulfotransferase, and tryptic BApNAase activities between larvae feeding on different hosts. Despite this, Manchurian ash-fed larvae produced a single isozyme of low electrophoretic mobility that was not produced in white or green ash-fed larvae. Additionally, larvae feeding on white and green ash produced two serine protease isozymes of high electrophoretic mobility that were not observed in Manchurian ash-fed larvae. We also found lower activity of β-glucosidase and higher activities of monoamine oxidase, ortho-quinone reductase, catalase, superoxide dismutase, and glutathione reductase in Manchurian ash-fed larvae compared to larvae that had fed on susceptible ash. A single isozyme was detected for both catalase and superoxide dismutase in all larval groups. The activities of the quinone-protective and antioxidant enzymes are consistent with the resistance phenotype of the host species, with the highest activities measured in larvae feeding on resistant Manchurian ash. We conclude that larvae feeding on Manchurian ash could be under quinone and oxidative stress, suggesting these may be potential mechanisms of resistance of Manchurian ash to EAB larvae, and that quinone-protective and antioxidant enzymes are important counter-adaptations of larvae for dealing with these resistance mechanisms. Copyright © 2015 Elsevier Ltd. All rights reserved.

Ultraviolet Satellite Measurements of Volcanic Ash. Chapter 12

NASA Technical Reports Server (NTRS)

Carn, S. A.; Krotkov, N. A.

2016-01-01

Ultraviolet (UV) remote sensing of volcanic ash and other absorbing aerosols from space began with the launch of the first Total Ozone Mapping Spectrometer (TOMS) instrument in 1978. Subsequent UV satellite missions (TOMS, GOME, SCIAMACHY, OMI, GOME-2, OMPS) have extended UV ash measurements to the present, generating a unique multidecadal record. A UV Aerosol Index (UVAI) based on two near-UV wavelengths, equally applicable to multispectral (TOMS, DSCOVR) or hyperspectral (GOME, SCIAMACHY, OMI, GOME-2, OMPS) instruments, has been used to derive a unique absorbing aerosol climatology across multiple UV satellite missions. Advantages of UV ash measurements relative to infrared (IR) techniques include the ability to detect ash at any altitude (assuming no clouds), above clouds, and over bright surfaces, where visible and IR techniques may fail. Disadvantages include the daytime-only restriction and nonspecificity to silicate ash, since UV measurements are sensitive to any UV-absorbing aerosol, including smoke, desert dust, and pollution. However, simultaneous retrieval of sulfur dioxide (SO2) abundance and UVAI provides robust discrimination of volcanic clouds. Although the UVAI is only semiquantitative, it has proved successful at detecting and tracking volcanic ash clouds from many volcanic eruptions since 1978. NASA A-Train measurements since 2006 (eg, CALIOP) have provided much improved constraints on volcanic ash altitude, and also permit identification of aerosol type through sensor synergy. Quantitative UV retrievals of ash optical depth, effective particle size, and ash column mass are possible and require assumptions of ash refractive index, particle size distribution, and ash layer altitude. The lack of extensive ash refractive index data in the UV-visible and the effects of ash particle shape on retrievals introduce significant uncertainty in the retrieved parameters, although limited validation against IR ash retrievals has been successful. In this contribution, we review UV ash detection and retrieval techniques and provide examples of volcanic eruptions detected in the approx. 37 year data record.

Study on the valorization routes of ashes from thermoelectric power plants working under mono-and co-combustion regimes

NASA Astrophysics Data System (ADS)

Barbosa, Rui Pedro Fernandes

The main objective of this thesis was to study new valorization routes of ashes produced in combustion and co-combustion processes. Three main valorization pathways were analyzed: (i)production of cement mortars, (ii) production of concretes, and (iii) use as chemical agents to remove contaminants from wastewaters. Firstly, the ashes produced during the mono-combustion of coal, co-combustion of coal and meat and bone meal (MBM), and mono-combustion of MBM were characterized. The aim of this study was to understand the ashes properties in extreme levels of substitution of coal by a residue with a high contamination of specific metals. The substitution of coal by MBM produced ashes with higher content of heavy metals. Secondly, the ashes coming from an industrial power plant working under mono-combustion(coal) and co-combustion conditions (coal+sewage sludge+MBM) were studied. The use of cofuels did not promote significant changes in the chemical and ecotoxicological properties of ashes. Fly ashes were successfully stabilized/solidified in cement mortar, and bottom and circulating ashes were successfully used as raw materials in concrete. The third step involved the characterization and valorization of biomass ashes resulting from the combustion of forestry residues. The highest concentrations of metals/metalloids were found in the lowest particle size fractions of ashes. Biomass ashes successfully substituted cement and natural aggregates in concretes, without compromising their mechanical, chemical, and ecotoxicological properties. Finally, the biomass ashes were tested as chemical agents to remove contaminants from wastewaters. The removal of P, mainly phosphates, and Pb from wastewaters was assayed. Biomass ashes presented a high capacity to remove phosphates. As fly ashes were more efficient in removing phosphates, they were further used to remove Pb from wastewaters. Again, they presented a high efficiency in Pb removal. New potential valorization routes for these ashes are now opened, contributing to improve their valorization rates.

Water Level Controls on Sap Flux of Canopy Species in Black Ash Wetlands

Treesearch

Joseph Shannon; Matthew Van Grinsven; Joshua Davis; Nicholas Bolton; Nam Noh; Thomas Pypker; Randall Kolka

2018-01-01

Black ash (Fraxinus nigra Marsh.) exhibits canopy dominance in regularly inundated wetlands, suggesting advantageous adaptation. Black ash mortality due to emerald ash borer (Agrilus planipennis Fairmaire) will alter canopy composition and site hydrology. Retention of these forested wetlands requires understanding black ash...

COAL-FIRED POWER PLANT ASH UTILIZATION IN THE TVA REGION

EPA Science Inventory

The report gives results of a study: (1) to summarize (a) production of coal ash nationally and by TVA's 12 major ash-producing steam/electric power plants, and (b) the physical/chemical characteristics of coal ash that affect ash disposal and/or use; (2) to review reported metho...

The relationship between the emerald ash borer (Agrilus planipennis) and ash (Fraxinus spp.) tree decline: Using visual canopy condition assessments and leaf isotope measurements to assess pest damage

Treesearch

Charles E. Flower; Kathleen S. Knight; Joanne Rebbeck; Miquel A. Gonzalez-Meler

2013-01-01

Ash trees (Fraxinus spp.) in North America are being severely impacted by the invasive emerald ash borer (Agrilus planipennis Fairmaire) which was inadvertently introduced to the US in the 1990s from Asia. The emerald ash borer (EAB) is a phloem boring beetle which relies exclusively on ash trees to complete its life cycle. Larvae...

Controlling formaldehyde emissions with boiler ash.

PubMed

Cowan, Jennifer; Abu-Daabes, Malyuba; Banerjee, Sujit

2005-07-01

Fluidized wood ash reduces formaldehyde in air from about 20 to <1 ppmv. Methanol is removed to a much lower extent. The efficiency of formaldehyde reduction increases with increasing moisture content of the ash. Sorption of formaldehyde to ash can be substantially accounted for by partitioning to the water contained in the ash followed by rate-controlling binding to the ash solids. Adsorption occurs at temperatures of up to 165 degrees C; oxidation predominates thereafter. It is proposed that formaldehyde could be stripped from an air stream in a fluidized bed containing ash, which could then be returned to a boiler to incinerate the formaldehyde.

The use of shale ash in dry mix construction materials

NASA Astrophysics Data System (ADS)

Gulbe, L.; Setina, J.; Juhnevica, I.

2017-10-01

The research was made to determine the use of shale ash usage in dry mix construction materials by replacing part of cement amount. Cement mortar ZM produced by SIA Sakret and two types of shale ashes from Narva Power plant (cyclone ash and electrostatic precipitator ash) were used. Fresh mortar properties, hardened mortar bulk density, thermal conductivity (λ10, dry) (table value) were tested in mortar ZM samples and mortar samples in which 20% of the amount of cement was replaced by ash. Compressive strenght, frost resistance and resistance to sulphate salt solutions were checked. It was stated that the use of electrostatic precipitator ash had a little change of the material properties, but the cyclone ash significantly reduced the mechanical strength of the material.

Sulfur-bearing coatings on fly ash from a coal-fired power plant: Composition, origin, and influence on ash alteration

USGS Publications Warehouse

Fishman, N.S.; Rice, C.A.; Breit, G.N.; Johnson, R.D.

1999-01-01

Fly ash samples collected from two locations in the exhaust stream of a coal-fired power plant differ markedly with respect to the abundance of thin (???0.1 ??m) sulfur-rich surface coatings that are observable by scanning electron microscopy. The coatings, tentatively identified as an aluminum-potassium-sulfate phase, probably form upon reaction between condensed sulfuric acid aerosols and glass surfaces, and are preferentially concentrated on ash exposed to exhaust stream gases for longer. The coatings are highly soluble and if sufficiently abundant, can impart an acidic pH to solutions initially in contact with ash. These observations suggest that proposals for ash use and predictions of ash behavior during disposal should consider the transient, acid-generating potential of some ash fractions and the possible effects on initial ash leachability and alteration. ?? 1998 Elsevier Science Ltd.

Fly ash carbon passivation

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

La Count, Robert B; Baltrus, John P; Kern, Douglas G

A thermal method to passivate the carbon and/or other components in fly ash significantly decreases adsorption. The passivated carbon remains in the fly ash. Heating the fly ash to about 500 and 800 degrees C. under inert gas conditions sharply decreases the amount of surfactant adsorbed by the fly ash recovered after thermal treatment despite the fact that the carbon content remains in the fly ash. Using oxygen and inert gas mixtures, the present invention shows that a thermal treatment to about 500 degrees C. also sharply decreases the surfactant adsorption of the recovered fly ash even though most ofmore » the carbon remains intact. Also, thermal treatment to about 800 degrees C. under these same oxidative conditions shows a sharp decrease in surfactant adsorption of the recovered fly ash due to the fact that the carbon has been removed. This experiment simulates the various "carbon burnout" methods and is not a claim in this method. The present invention provides a thermal method of deactivating high carbon fly ash toward adsorption of AEAs while retaining the fly ash carbon. The fly ash can be used, for example, as a partial Portland cement replacement in air-entrained concrete, in conductive and other concretes, and for other applications.« less

Can pore-clogging by ash explain post-fire runoff?

USGS Publications Warehouse

Stoof, Cathelijne R.; Gevaert, Anouk I.; Baver, Christine; Hassanpour, Bahareh; Morales, Veronica L.; Zhang, Wei; Martin, Deborah; Giri, Shree K.; Steenhuis, Tammo S.

2016-01-01

Ash plays an important role in controlling runoff and erosion processes after wildfire and has frequently been hypothesised to clog soil pores and reduce infiltration. Yet evidence for clogging is incomplete, as research has focussed on identifying the presence of ash in soil; the actual flow processes remain unknown. We conducted laboratory infiltration experiments coupled with microscope observations in pure sands, saturated hydraulic conductivity analysis, and interaction energy calculations, to test whether ash can clog pores (i.e. block pores such that infiltration is hampered and ponding occurs). Although results confirmed previous observations of ash washing into pores, clogging was not observed in the pure sands tested, nor were conditions found for which this does occur. Clogging by means of strong attachment of ash to sand was deemed unlikely given the negative surface charge of the two materials. Ponding due to washing in of ash was also considered improbable given the high saturated conductivity of pure ash and ash–sand mixtures. This first mechanistic step towards analysing ash transport and attachment processes in field soils therefore suggests that pore clogging by ash is unlikely to occur in sands. Discussion is provided on other mechanisms by which ash can affect post-fire hydrology.

Biotic and abiotic factors affect green ash volatile production and emerald ash borer adult feeding preference.

PubMed

Chen, Yigen; Poland, Therese M

2009-12-01

The emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is an exotic woodborer first detected in 2002 in Michigan and Ontario and is threatening the ash resource in North America. We examined the effects of light exposure and girdling on green ash (Fraxinus pennsylvanica Marsh) volatile production, and effects of light exposure, girdling, and leaf age on emerald ash borer adult feeding preferences and phototaxis. Green ash seedlings grown under higher light exposure had lower amounts of three individual volatile compounds, (Z)-3-hexenol, (E)-beta-ocimene, and (Z,E)-alpha-farnesene, as well as the total amount of six detected volatile compounds. Girdling did not affect the levels of these volatiles. Emerald ash borer females preferred mature leaves, leaves from girdled trees, and leaves grown in the sun over young leaves, leaves from nongirdled trees, and leaves grown in the shade, respectively. These emerald ash borer preferences were most likely because of physical, nutritional, or biochemical changes in leaves in response to the different treatments. Emerald ash borer females and males showed positive phototaxis in laboratory arenas, a response consistent with emerald ash borer preference for host trees growing in sunlight.

Optical properties of volcanic ash: improving remote sensing observations.

NASA Astrophysics Data System (ADS)

Whelley, Patrick; Colarco, Peter; Aquila, Valentina; Krotkov, Nickolay; Bleacher, Jake; Garry, Brent; Young, Kelsey; Rocha Lima, Adriana; Martins, Vanderlei; Carn, Simon

2016-04-01

Many times each year explosive volcanic eruptions loft ash into the atmosphere. Global travel and trade rely on aircraft vulnerable to encounters with airborne ash. Volcanic ash advisory centers (VAACs) rely on dispersion forecasts and satellite data to issue timely warnings. To improve ash forecasts model developers and satellite data providers need realistic information about volcanic ash microphysical and optical properties. In anticipation of future large eruptions we can study smaller events to improve our remote sensing and modeling skills so when the next Pinatubo 1991 or larger eruption occurs, ash can confidently be tracked in a quantitative way. At distances >100km from their sources, drifting ash plumes, often above meteorological clouds, are not easily detected from conventional remote sensing platforms, save deriving their quantitative characteristics, such as mass density. Quantitative interpretation of these observations depends on a priori knowledge of the spectral optical properties of the ash in UV (>0.3μm) and TIR wavelengths (>10μm). Incorrect assumptions about the optical properties result in large errors in inferred column mass loading and size distribution, which misguide operational ash forecasts. Similarly, simulating ash properties in global climate models also requires some knowledge of optical properties to improve aerosol speciation.

Treatment of fly ash from power plants using thermal plasma.

PubMed

Al-Mayman, Sulaiman; AlShunaifi, Ibrahim; Albeladi, Abdullah; Ghiloufi, Imed; Binjuwair, Saud

2017-01-01

Fly ash from power plants is very toxic because it contains heavy metals. In this study fly ash was treated with a thermal plasma. Before their treatment, the fly ash was analyzed by many technics such as X-ray fluorescence, CHN elemental analysis, inductively coupled plasma atomic emission spectroscopy and scanning electron microscopy. With these technics, the composition, the chemical and physical proprieties of fly ash are determined. The results obtained by these analysis show that fly ash is mainly composed of carbon, and it contains also sulfur and metals such as V, Ca, Mg, Na, Fe, Ni, and Rh. The scanning electron microscopy analysis shows that fly ash particles are porous and have very irregular shapes with particle sizes of 20-50 μm. The treatment of fly ash was carried out in a plasma reactor and in two steps. In the first step, fly ash was treated in a pyrolysis/combustion plasma system to reduce the fraction of carbon. In the second step, the product obtained by the combustion of fly ash was vitrified in a plasma furnace. The leaching results show that the fly ash was detoxified by plasma vitrification and the produced slag is amorphous and glassy.

Treatment of fly ash from power plants using thermal plasma

PubMed Central

Al-Mayman, Sulaiman; AlShunaifi, Ibrahim; Albeladi, Abdullah; Binjuwair, Saud

2017-01-01

Fly ash from power plants is very toxic because it contains heavy metals. In this study fly ash was treated with a thermal plasma. Before their treatment, the fly ash was analyzed by many technics such as X-ray fluorescence, CHN elemental analysis, inductively coupled plasma atomic emission spectroscopy and scanning electron microscopy. With these technics, the composition, the chemical and physical proprieties of fly ash are determined. The results obtained by these analysis show that fly ash is mainly composed of carbon, and it contains also sulfur and metals such as V, Ca, Mg, Na, Fe, Ni, and Rh. The scanning electron microscopy analysis shows that fly ash particles are porous and have very irregular shapes with particle sizes of 20–50 μm. The treatment of fly ash was carried out in a plasma reactor and in two steps. In the first step, fly ash was treated in a pyrolysis/combustion plasma system to reduce the fraction of carbon. In the second step, the product obtained by the combustion of fly ash was vitrified in a plasma furnace. The leaching results show that the fly ash was detoxified by plasma vitrification and the produced slag is amorphous and glassy. PMID:28546898

MSW fly ash stabilized with coal ash for geotechnical application.

PubMed

Kamon, M; Katsumi, T; Sano, Y

2000-09-15

The solidification and stabilization of municipal solid waste (MSW) fly ash for the purpose of minimizing the geo-environmental impact caused by toxic heavy metals as well as ensuring engineering safety (strength and soaking durability) are experimentally evaluated. The mixtures of MSW fly ash stabilized with cement and fluidized bed combustion coal fly ash (FCA) were used for unconfined compressive strength tests, leachate tests, and soaking tests. The behavior of soluble salts contained in the MSW fly ash significantly affects strength development, soaking durability, and the hardening reaction of the stabilized MSW fly ash mixtures. The cement stabilization of the MSW fly ash does not have enough effect on strength development and soaking durability. The addition of cement only contributes to the containment of heavy metals due to the high level of alkalinity. When using FCA as a stabilizing agent for MSW fly ash, the mixture exhibits high strength and durability. However, the Cd leachate cannot be prevented in the early stages of curing. Using a combination of cement and FCA as a MSW fly ash stabilizer can attain high strength, high soaking durability, and the containment of heavy metals. The stabilized MSW fly ash with cement and FCA can be practically applied to embankments.

Active mineral additives of sapropel ashes

NASA Astrophysics Data System (ADS)

Khomich, V. A.; Danilina, E. V.; Krivonos, O. I.; Plaksin, G. V.

2015-01-01

The goal of the presented research is to establish a scientific rational for the possibility of sapropel ashes usage as an active mineral additive. The research included the study of producing active mineral additives from sapropels by their thermal treatment at 850900 °C and afterpowdering, the investigation of the properties of paste matrix with an ash additive, and the study of the ash influence on the cement bonding agent. Thermogravimetric analysis and X-ray investigations allowed us to establish that while burning, organic substances are removed, clay minerals are dehydrated and their structure is broken. Sapropel ashes chemical composition was determined. An amorphous ash constituent is mainly formed from silica of the mineral sapropel part and alumosilicagels resulted from clay minerals decomposition. Properties of PC 400 and PC 500A0 sparopel ash additives were studied. Adding ashes containing Glenium plasticizer to the cement increases paste matrix strength and considerably reduces its water absorption. X-ray phase analysis data shows changes in the phase composition of the paste matrix with an ash additive. Ash additives produce a pozzolanic effect on the cement bonding agent. Besides, an ash additive due to the alumosilicagels content causes transformation from unstable calcium aluminate forms to the stable ones.

Influence of Cements Containing Calcareous Fly Ash as a Main Component Properties of Fresh Cement Mixtures

NASA Astrophysics Data System (ADS)

Gołaszewski, Jacek; Kostrzanowska-Siedlarz, Aleksandra; Ponikiewski, Tomasz; Miera, Patrycja

2017-10-01

The main goal of presented research was to examine usability of cements containing calcareous fly ash (W) from technological point of view. In the paper the results of tests concerning the influence of CEM II and CEM IV cements containing fly ash (W) on rheological properties, air content, setting times and plastic shrinkage of mortars are presented and discussed. Moreover, compatibility of plasticizers with cements containing fly ash (W) was also studied. Additionally, setting time and hydration heat of cements containing calcareous fly ash (W) were determined. In a broader aspect, the research contributes to promulgation of the possibility of using calcareous fly ash (W) in cement and concrete technology, what greatly benefits the environment protection (utilization of waste fly ash). Calcareous fly ash can be used successfully as the main component of cement. Cements produced by blending with processed fly ash or cements produced by interginding are characterized by acceptable technological properties. In respect to CEM I cements, cements containing calcareous fly ash worsen workability, decrease air content, delay setting time of mixtures. Cements with calcareous fly ash show good compatibility with plasticizers.

Tentative to use wastes from thermal power plants for construction building materials

NASA Astrophysics Data System (ADS)

Bui, Quoc-Bao; Phan, To-Anh-Vu; Tran, Minh-Tung; Le, Duc-Hien

2018-04-01

Thermal power plants (TPP) generates wastes (bottom and fly ashes) which become a serious environmental problem in Vietnam. Indeed, although in several countries fly ash can be used for cement industry, fly ash from actual TPP in Vietnam does not have enough good quality for cement production, because the fly ash treatment phase has not yet included in the generations of existing Vietnamese TPP. That is why bottom ash and fly ash purely become wastes and their evacuation is an urgent demand of the society. This paper presents an investigation using fly and bottom ashes in the manufacturing of construction materials. The main aims of this study is to reduce environmental impacts of fly and bottom ashes, and to test another non-conventional binder to replace cement in the manufacture of unburnt bricks. Several proportions of fly ash, bottom ash, cement, gravel, sand and water were tested to manufacture concretes. Then, geopolymer was prepared from the fly ash and an activator. Specimens were tested in uniaxial compressions. Results showed that the cement concrete tested had the compressive strengths which could be used for low rise constructions and the material using geopolymer could be used for non-load-bearing materials (unburnt bricks).

Economic analysis of emerald ash borer (Coleoptera: Buprestidae) management options.

PubMed

Vannatta, A R; Hauer, R H; Schuettpelz, N M

2012-02-01

Emerald ash borer, Agrilus planipennis (Fairmaire) (Coleoptera: Buprestidae), plays a significant role in the health and extent of management of native North American ash species in urban forests. An economic analysis of management options was performed to aid decision makers in preparing for likely future infestations. Separate ash tree population valuations were derived from the i-Tree Streets program and the Council of Tree and Landscape Appraisers (CTLA) methodology. A relative economic analysis was used to compare a control option (do-nothing approach, only removing ash trees as they die) to three distinct management options: 1) preemptive removal of all ash trees over a 5 yr period, 2) preemptive removal of all ash trees and replacement with comparable nonash trees, or 3) treating the entire population of ash trees with insecticides to minimize mortality. For each valuation and management option, an annual analysis was performed for both the remaining ash tree population and those lost to emerald ash borer. Retention of ash trees using insecticide treatments typically retained greater urban forest value, followed by doing nothing (control), which was better than preemptive removal and replacement. Preemptive removal without tree replacement, which was the least expensive management option, also provided the lowest net urban forest value over the 20-yr simulation. A "no emerald ash borer" scenario was modeled to further serve as a benchmark for each management option and provide a level of economic justification for regulatory programs aimed at slowing the movement of emerald ash borer.

Nitrogen mineralization from sludge in an alkaline, saline coal gasification ash environment.

PubMed

Mbakwe, Ikenna; De Jager, Pieter C; Annandale, John G; Matema, Taurai

2013-01-01

Rehabilitating coal gasification ash dumps by amendment with waste-activated sludge has been shown to improve the physical and chemical properties of ash and to facilitate the establishment of vegetation. However, mineralization of organic N from sludge in such an alkaline and saline medium and the effect that ash weathering has on the process are poorly understood and need to be ascertained to make decisions regarding the suitability of this rehabilitation option. This study investigated the rate and pattern of N mineralization from sludge in a coal gasification ash medium to determine the prevalent inorganic N form in the system and assess the effect of ash weathering on N mineralization. An incubation experiment was performed in which fresh ash, weathered ash, and soil were amended with the equivalent of 90 Mg ha sludge, and N mineralization was evaluated over 63 d. More N (24%) was mineralized in fresh ash than in weathered ash and soil, both of which mineralized 15% of the initial organic N in sludge. More nitrification occurred in soil, and most of the N mineralized in ash was in the form of ammonium, indicating an inhibition of nitrifying organisms in the ash medium and suggesting that, at least initially, plants used for rehabilitation of coal gasification ash dumps will take up N mostly as ammonium. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Feasible experimental study on the utilization of a 300 MW CFB boiler desulfurizating bottom ash for construction applications

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

Lu, X.F.; Amano, R.S.

2006-12-15

CFB boiler ash cannot be used as a cement replacement in concrete due to its unacceptably high sulfur content. The disposal in landfills has been the most common means of handling ash in circulating fluidized bed boiler power plants. However for a 300 MW CFB boiler power plant, there will be 600,000 tons of ash discharged per year and will result in great volumes and disposal cost of ash byproduct. It was very necessary to solve the utilization of CFB ash and to decrease the disposal cost of CFB ash. The feasible experimental study results on the utilization of themore » bottom ashes of a 300 MW CFB boiler in Baima power plant in China were reported in this paper. The bottom ashes used for test came from the discharged bottom ashes in a 100 MW CFB boiler in which the anthracite and limestone designed for the 300 MW CFB project was burned. The results of this study showed that the bottom ash could be used for cementitious material, road concrete, and road base material. The masonry cements, road concrete with 30 MPa compressive strength and 4.0 MPa flexural strength, and the road base material used for base courses of the expressway, the main road and the minor lane were all prepared with milled CFB bottom ashes in the lab. The better methods of utilization of the bottom ashes were discussed in this paper.« less

Assessment of mobility and bioavailability of contaminants in MSW incineration ash with aquatic and terrestrial bioassays.

PubMed

Ribé, V; Nehrenheim, E; Odlare, M

2014-10-01

Incineration of municipal solid waste (MSW) is a waste treatment method which can be sustainable in terms of waste volume reduction as well as a source of renewable energy. In the process fly and bottom ash is generated as a waste material. The ash residue may vary greatly in composition depending on the type of waste incinerated and it can contain elevated levels of harmful contaminants such as heavy metals. In this study, the ecotoxicity of a weathered, untreated incineration bottom ash was characterized as defined by the H14 criterion of the EU Waste Framework Directive by means of an elemental analysis, leaching tests followed by a chemical analysis and a combination of aquatic and solid-phase bioassays. The experiments were conducted to assess the mobility and bioavailability of ash contaminants. A combination of aquatic and terrestrial bioassays was used to determine potentially adverse acute effects of exposure to the solid ash and aqueous ash leachates. The results from the study showed that the bottom ash from a municipal waste incineration plant in mid-Sweden contained levels of metals such as Cu, Pb and Zn, which exceeded the Swedish EPA limit values for inert wastes. The chemical analysis of the ash leachates showed high concentrations of particularly Cr. The leachate concentration of Cr exceeded the limit value for L/S 10 leaching for inert wastes. Filtration of leachates prior to analysis may have underestimated the leachability of complex-forming metals such as Cu and Pb. The germination test of solid ash and ash leachates using T. repens showed a higher inhibition of seedling emergence of seeds exposed to the solid ash than the seeds exposed to ash leachates. This indicated a relatively low mobility of toxicants from the solid ash into the leachates, although some metals exceeded the L/S 10 leaching limit values for inert wastes. The Microtox® toxicity test showed only a very low toxic response to the ash leachate exposure, while the D. magna immobility test showed a moderately high toxic effect of the ash leachates. Overall, the results from this study showed an ecotoxic effect of the solid MSW bottom ash and the corresponding ash leachates. The material may therefore pose an environmental risk if used in construction applications. However, as the testing of the solid ash was rather limited and the ash leachate showed an unusually high leaching of Cr, further assessments are required in order to conclusively characterize the bottom ash studied herein as hazardous according to the H14 criterion. Copyright © 2014 Elsevier Ltd. All rights reserved.

Wildland fire ash: Production, composition and eco-hydro-geomorphic effects

USGS Publications Warehouse

Bodi, Merche B.; Martin, Deborah; Balfour, Victoria N.; Santin, Cristina; Doerr, Stefan H.; Pereira, Paulo; Cerda, Artemi; Mataix-Solera, Jorge

2014-01-01

Fire transforms fuels (i.e. biomass, necromass, soil organic matter) into materials with different chemical and physical properties. One of these materials is ash, which is the particulate residue remaining or deposited on the ground that consists of mineral materials and charred organic components. The quantity and characteristics of ash produced during a wildland fire depend mainly on (1) the total burned fuel (i.e. fuel load), (2) fuel type and (3) its combustion completeness. For a given fuel load and type, a higher combustion completeness will reduce the ash organic carbon content, increasing the relative mineral content, and hence reducing total mass of ash produced. The homogeneity and thickness of the ash layer can vary substantially in space and time and reported average thicknesses range from close to 0 to 50 mm. Ash is a highly mobile material that, after its deposition, may be incorporated into the soil profile, redistributed or removed from a burned site within days or weeks by wind and water erosion to surface depressions, footslopes, streams, lakes, reservoirs and, potentially, into marine deposits.Research on the composition, properties and effects of ash on the burned ecosystem has been conducted on material collected in the field after wildland and prescribed fires as well as on material produced in the laboratory. At low combustion completeness (typically T < 450 °C), ash is organic-rich, with organic carbon as the main component. At high combustion completeness (T > 450 °C), most organic carbon is volatized and the remaining mineral ash has elevated pH when in solution. It is composed mainly of calcium, magnesium, sodium, potassium, silicon and phosphorous in the form of inorganic carbonates, whereas at T > 580 °C the most common forms are oxides. Ash produced under lower combustion completeness is usually darker, coarser, and less dense and has a higher saturated hydraulic conductivity than ash with higher combustion completeness, although physical reactions with CO2 and when moistened produce further changes in ash characteristics.As a new material present after a wildland fire, ash can have profound effects on ecosystems. It affects biogeochemical cycles, including the C cycle, not only within the burned area, but also globally. Ash incorporated into the soil increases temporarily soil pH and nutrient pools and changes physical properties such as albedo, soil texture and hydraulic properties including water repellency. Ash modifies soil hydrologic behavior by creating a two-layer system: the soil and the ash layer, which can function in different ways depending on (1) ash depth and type, (2) soil type and (3) rainfall characteristics. Key parameters are the ash's water holding capacity, hydraulic conductivity and its potential to clog soil pores. Runoff from burned areas carries soluble nutrients contained in ash, which can lead to problems for potable water supplies. Ash deposition also stimulates soil microbial activity and vegetation growth.Further work is needed to (1) standardize methods for investigating ash and its effects on the ecosystem, (2) characterize ash properties for specific ecosystems and wildland fire types, (3) determine the effects of ash on human and ecosystem health, especially when transported by wind or water, (4) investigate ash's controls on water and soil losses at slope and catchment scales, (5) examine its role in the C cycle, and (6) study its redistribution and fate in the environment.

Characterization of fly ash from low-sulfur and high-sulfur coal sources: Partitioning of carbon and trace elements with particle size

USGS Publications Warehouse

Hower, J.C.; Trimble, A.S.; Eble, C.F.; Palmer, C.A.; Kolker, A.

1999-01-01

Fly ash samples were collected in November and December of 1994, from generating units at a Kentucky power station using high- and low-sulfur feed coals. The samples are part of a two-year study of the coal and coal combustion byproducts from the power station. The ashes were wet screened at 100, 200, 325, and 500 mesh (150, 75, 42, and 25 ??m, respectively). The size fractions were then dried, weighed, split for petrographic and chemical analysis, and analyzed for ash yield and carbon content. The low-sulfur "heavy side" and "light side" ashes each have a similar size distribution in the November samples. In contrast, the December fly ashes showed the trend observed in later months, the light-side ash being finer (over 20 % more ash in the -500 mesh [-25 ??m] fraction) than the heavy-side ash. Carbon tended to be concentrated in the coarse fractions in the December samples. The dominance of the -325 mesh (-42 ??m) fractions in the overall size analysis implies, though, that carbon in the fine sizes may be an important consideration in the utilization of the fly ash. Element partitioning follows several patterns. Volatile elements, such as Zn and As, are enriched in the finer sizes, particularly in fly ashes collected at cooler, light-side electrostatic precipitator (ESP) temperatures. The latter trend is a function of precipitation at the cooler-ESP temperatures and of increasing concentration with the increased surface area of the finest fraction. Mercury concentrations are higher in high-carbon fly ashes, suggesting Hg adsorption on the fly ash carbon. Ni and Cr are associated, in part, with the spinel minerals in the fly ash. Copyright ?? 1999 Taylor & Francis.

The influence of using volcanic ash and lime ash as filler on compressive strength in self compacting concrete

NASA Astrophysics Data System (ADS)

Karolina, Rahmi; Panatap Simanjuntak, Murydrischy

2018-03-01

Self Compacting Concrete (SCC) is a technology which is developing today in which concrete solidifies by itself without using vibrator. Casting conventional concrete which has a lot of reinforcement bars sometimes finds difficulty in achieving optimal solidity. The method used to solve this problem is by using SCC technology. SCC was made by using filler, volcanic ash, and lime ash as the filling materials so that the concrete became more solid and hollow space could be filled up. The variation of using these two materials was 10%, 15%, 20%, and 25% of the cementitious mass and using 1% of superplasticizer from cementitious material. The supporting testing was done by using the test when the concrete was still fluid and when it was solid. Malleable concrete was tested by using EFNARC 2002 standard in slump flow test, v-funnel test, l-shaped box test, and j-ring test to obtain filling ability and passing ability. In this malleable lime concrete test, there was the decrease, compared with normal SCC concrete without adding volcanic ash and lime ash. Testing was also done in solid concrete in compressive strength, tensile strength, and concrete absorption. The result of the testing showed that the optimum tensile strength in Variation 1, without volcanic ash and lime ash – with 1% of superplasticizer was 39.556 MPa, the optimum tensile strength in Variation 1, without volcanic ash and lime ash- with 1% of super-plasticizer was 3.563 MPa, while the value of optimum absorption which occurred in Variation 5 (25% of volcanic ash + 25% of lime ash + 50% of cement + 1% of superplasticizer) was 1.313%. This was caused by the addition of volcanic ash and lime ash which had high water absorption.

Comparison of heterogeneous photolytic reduction of Hg(II) in the coal fly ashes and synthetic aerosols

NASA Astrophysics Data System (ADS)

Tong, Yindong; Eichhorst, Terry; Olson, Michael R.; Rutter, Andrew P.; Shafer, Martin M.; Wang, Xuejun; Schauer, James J.

2014-03-01

In this study, we examined the heterogeneous reduction of Hg(II) on the coal fly ash samples and synthetic aerosols under different light conditions in a controlled laboratory reactor. Three types of coal fly ashes were studied: a high carbon fly ash from a stoker boiler, a low carbon/low sulfate fly ash from a pulverized coal combustor burning low sulfur coal, and a high sulfate fly ash from a pulverized coal combustor burning high sulfur coal. The rate of Hg(II) reduction on the three diverse fly ash samples was found to be relatively fast with an average half-life of 1.6 h under clear sky atmospheric conditions (under the irradiance of 1000 W/m2). The reduction rate in the low sulfate/low carbon fly ash was approximately 1.5 times faster than with the other coal fly ash samples. Synthetic aerosols made of carbon black and levoglucosan produced Hg(II) reduction rates similar to coal fly ashes. However, aerosols composed of adipic acid resulted in reduction rates that were 3-5 times faster. The sensitivity of adipic acid reduction to light source wavelength was found to be greater than for the coal fly ash and other synthetic aerosols. Aerosols made from the water extracts of coal fly ash samples produced reduction rates equal to or slightly higher than with the native fly ash suggesting that the soluble components of fly ash play a significant role in the reduction mechanism. The measured reduction rates are likely important in the chemical processing of mercury in power plant plumes and potentially in the atmosphere and should be considered for incorporation in atmospheric transport models that are used to understand the fate of atmospheric mercury.

Nutritional attributes of ash (Fraxinus spp.) outer bark and phloem and their relationships to resistance against the emerald ash borer.

PubMed

Hill, Amy L; Whitehill, Justin G A; Opiyo, Stephen O; Phelan, P Larry; Bonello, Pierluigi

2012-12-01

The emerald ash borer (Agrilus planipennis Fairmaire, EAB) is an alien, invasive wood-boring insect that is responsible for killing millions of ash trees since its discovery in North America in 2002. All North American ash species (Fraxinus spp.) that EAB has encountered have shown various degrees of susceptibility, while Manchurian ash (Fraxinus mandshurica Ruprecht), which shares a co-evolutionary history with this insect, is resistant. Recent studies have looked into constitutive resistance mechanisms in Manchurian ash, concentrating on the secondary phloem, which is the feeding substrate for the insect. In addition to specialized metabolism and defense-related components, primary metabolites and nutritional summaries can also be important to understand the feeding behavior of insect herbivores. Here, we have compared the nutritional characteristics (water content, total protein, free amino acids, total soluble sugars and starch, percent carbon and nitrogen, and macro- and micronutrients) of outer bark and phloem from black, green, white and Manchurian ash to determine their relevance to resistance or susceptibility to EAB. Water content and concentrations of Al, Ba, Cu, Fe, K, Li, tryptophan and an unknown compound were found to separate black and Manchurian ash from green and white ash in a principal component analysis (PCA), confirming their phylogenetic placements into two distinct clades. The traits that distinguished Manchurian ash from black ash in the PCA were water content and concentrations of total soluble sugars, histidine, lysine, methionine, ornithine, proline, sarcosine, tyramine, tyrosol, Al, Fe, K, Na, V and an unknown compound. However, only proline, tyramine and tyrosol were significantly different, and higher, in Manchurian ash than in black ash.

Lube oil-dependent ash chemistry on soot oxidation reactivity in a gasoline direct-injection engine

DOE PAGES

Choi, Seungmok; Seong, Heeje

2016-09-30

Gasoline particulate filters (GPF) are considered an enabling technology to meet stringent particulate matter (PM) regulations for gasoline direct-injection (GDI) engines, which are known to produce significant PM emissions. While ash loading in filters has been recognized to be detrimental in filter performance by increasing back pressure, increased ash fractions in soot were observed to enhance soot oxidation. In this study, GDI soot samples derived from different gasoline/lube oil blends were evaluated to identify potential promoting factors when formulated lube oils were dosed into gasoline fuel. Ca-derived ash enhanced soot oxidation remarkably, while P- and ZDDP-derived ash deteriorated soot oxidation.more » It is apparent that the promoting effect of lube oil-derived ash is due mainly to the Ca component that is the most abundant among additive components in lube oil. Bulk and surface analyses of these ash compounds indicate that Ca-derived ash would be complex compounds, while the contribution of CaSO 4, which is one of the most abundant ash compounds from diesel engines, is almost negligible. For the validation of the ash promoting impact in filters, the regeneration experiments were compared for a TWC-coated GPF in a GDI engine before and after ash loading was performed. The pressure drop of the ash-loaded GPF decreased noticeably in the initial regeneration stage and it increased gradually, whereas that of no ash-loaded GPF increased gradually without any reduction. So, it is concluded that the ash layer in the GPF assisted soot oxidation in the early regeneration stage when it was in close contact with soot.« less

High-efficiency cogeneration boiler bagasse-ash geochemistry and mineralogical change effects on the potential reuse in synthetic zeolites, geopolymers, cements, mortars, and concretes.

PubMed

Clark, Malcolm W; Despland, Laure M; Lake, Neal J; Yee, Lachlan H; Anstoetz, Manuela; Arif, Elisabeth; Parr, Jeffery F; Doumit, Philip

2017-04-01

Sugarcane bagasse ash re-utilisation has been advocated as a silica-rich feed for zeolites, pozzolans in cements and concretes, and geopolymers. However, many papers report variable success with the incorporation of such materials in these products as the ash can be inconsistent in nature. Therefore, understanding what variables affect the ash quality in real mills and understanding the processes to characterise ashes is critical in predicting successful ash waste utilisation. This paper investigated sugarcane bagasse ash from three sugar mills (Northern NSW, Australia) where two are used for the co-generation of electricity. Data shows that the burn temperatures of the bagasse in the high-efficiency co-generation boilers are much higher than those reported at the temperature measuring points. Silica polymorph transitions indicate the high burn temperatures of ≈1550 °C, produces ash dominated α -quartz rather than expected α-cristobilite and amorphous silica; although α-cristobilite, and amorphous silica are present. Furthermore, burn temperatures must be ≤1700 °C, because of the absence of lechatelierite where silica fusing and globulisation dominates. Consequently, silica-mineralogy changes deactivate the bagasse ash by reducing silica solubility, thus making bagasse ash utilisation in synthetic zeolites, geopolymers, or a pozzolanic material in mortars and concretes more difficult. For the ashes investigated, use as a filler material in cements and concrete has the greatest potential. Reported mill boiler temperatures discrepancies and the physical characteristics of the ash, highlight the importance of accurate temperature monitoring at the combustion seat if bagasse ash quality is to be prioritised to ensure a usable final ash product.

Lube oil-dependent ash chemistry on soot oxidation reactivity in a gasoline direct-injection engine

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

Choi, Seungmok; Seong, Heeje

Gasoline particulate filters (GPF) are considered an enabling technology to meet stringent particulate matter (PM) regulations for gasoline direct-injection (GDI) engines, which are known to produce significant PM emissions. While ash loading in filters has been recognized to be detrimental in filter performance by increasing back pressure, increased ash fractions in soot were observed to enhance soot oxidation. In this study, GDI soot samples derived from different gasoline/lube oil blends were evaluated to identify potential promoting factors when formulated lube oils were dosed into gasoline fuel. Ca-derived ash enhanced soot oxidation remarkably, while P- and ZDDP-derived ash deteriorated soot oxidation.more » It is apparent that the promoting effect of lube oil-derived ash is due mainly to the Ca component that is the most abundant among additive components in lube oil. Bulk and surface analyses of these ash compounds indicate that Ca-derived ash would be complex compounds, while the contribution of CaSO 4, which is one of the most abundant ash compounds from diesel engines, is almost negligible. For the validation of the ash promoting impact in filters, the regeneration experiments were compared for a TWC-coated GPF in a GDI engine before and after ash loading was performed. The pressure drop of the ash-loaded GPF decreased noticeably in the initial regeneration stage and it increased gradually, whereas that of no ash-loaded GPF increased gradually without any reduction. So, it is concluded that the ash layer in the GPF assisted soot oxidation in the early regeneration stage when it was in close contact with soot.« less

Photosynthetic pigment concentrations, gas exchange and vegetative growth for selected monocots and dicots treated with two contrasting coal fly ashes

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

Yunusa, I.A.M.; Burchett, M.D.; Manoharan, V.

2009-07-15

There is uncertainty as to the rates of coal fly ash needed for optimum physiological processes and growth. In the current study we tested the hyothesis that photosynthetic pigments concentrations and CO{sub 2} assimilation (A) are more sensitive than dry weights in plants grown on media amended with coal fly ash. We applied the Terrestrial Plant Growth Test (Guideline 208) protocols of the Organization for Economic Cooperation and Development (OECD) to monocots (barley (Hordeum vulgare) and ryegrass (Secale cereale)) and dicots (canola (Brasica napus), radish (Raphanus sativus), field peas (Pisum sativum), and lucerne (Medicago sativa)) on media amended with flymore » ashes derived from semi-bituminous (gray ash) or lignite (red ash) coals at rates of 0, 2.5, 5.0, 10, or 20 Mg ha(-1). The red ash had higher elemental concentrations and salinity than the gray ash. Fly ash addition had no significant effect on germination by any of the six species. At moderate rates ({<=}10 Mg ha{sup -1}) both ashes increased (P < 0.05) growth rates and concentrations of chlorophylls a and b, but reduced carotenoid concentrations. Addition of either ash increased A in radish and transpiration in barley. Growth rates and final dry weights were reduced for all of the six test species when addition rates exceeded 10 Mg ha{sup -1} for gray ash and 5 Mg ha{sup -1} for red ash. We concluded that plant dry weights, rather than pigment concentrations and/or instantaneous rates of photosynthesis, are more consistent for assessing subsequent growth in plants supplied with fly ash.« less

Characterizations of Deposited Ash During Co-Firing of White Pine and Lignite in Fluidized Bed Combustor

NASA Astrophysics Data System (ADS)

Shao, Yuanyuan; Zhu, Jesse; Preto, Fernando; Tourigny, Guy; Wang, Jinsheng; Badour, Chadi; Li, Hanning; Xu, Chunbao Charles

Characterizations of ash deposits from co-firing/co-combusting of a woody biomass (i.e., white pine) and lignite coal were investigated in a fluidized-bed combustor using a custom designed air-cooled probe installed in the freeboard region of the reactor. Ash deposition behaviors on a heat transfer surface were comprehensively investigated and discussed under different conditions including fuel type, fuel blending ratios (20-80% biomass on a thermal basis), and moisture contents. For the combustion of 100% lignite, the compositions of the deposited ash were very similar to those of the fuel ash, while in the combustion of 100% white pine pellets or sawdust the deposited ash contained a much lower contents of CaO, SO3, K2O and P2O5 compared with the fuel ash, but the deposited ash was enriched with SiO2, Al2O3 and MgO. A small addition of white pine (20% on a heat input basis) to the coal led to the highest ash deposition rates likely due to the strong interaction of the CaO and MgO (from the biomass ash) with the alumina and silica (from the lignite ash) during the co-combustion process, evidenced by the detection of high concentrations of calcium/magnesium sulfates, aluminates and silicates in the ash deposits. Interestingly, co-firing of white pine pellets and lignite at a 50% blending ratio led to the lowest ash deposition rates. Ash deposition rates in combustion of fuels as received with a higher moisture content was found to be much lower than those of oven-dried fuels.

Characterization of metals released from coal fly ash during dredging at the Kingston ash recovery project.

PubMed

Bednar, A J; Averett, D E; Seiter, J M; Lafferty, B; Jones, W T; Hayes, C A; Chappell, M A; Clarke, J U; Steevens, J A

2013-09-01

A storage-pond dike failure occurred on December 22, 2008 at the Tennessee Valley Authority Kingston Fossil Plant resulting in the release of over 4million cubic meters (5million cubic yards) of fly ash. Approximately half of the released ash was deposited in the main channel of the Emory River, Tennessee, USA. Remediation efforts of the Emory River focused on hydraulic dredging, as well as mechanical excavation in targeted areas. However, agitation of the submerged fly ash during hydraulic dredging introduces river water into the fly ash material, which could promote dissolution and desorption of metals from the solid fly ash material. Furthermore, aeration of the dredge slurry could alter the redox state of metals in the fly ash material and thereby change their sorption, mobility, and toxicity properties. The research presented here focuses on the concentrations and speciation of metals during the fly ash recovery from the Emory River. Our results indicate that arsenite [As(III)] released from the fly ash material during dredging was slowly oxidized to arsenate [As(V)] in the slurry recovery system with subsequent removal through precipitation or sorption reactions with suspended fly ash material. Concentrations of other dissolved metals, including iron and manganese, also generally decreased in the ash recovery system prior to water discharge back to the river. Published by Elsevier Ltd.

Remobilisation of industrial lead depositions in ash during Australian wildfires.

PubMed

Wu, Liqin; Taylor, Mark Patrick; Handley, Heather K

2017-12-01

This study examined the recycling of lead (Pb) in ash from wildfires, its source and potential contribution to environmental contamination. Ash from wildfires was collected from four Australian sites following uncontrolled fires during 2012 to 2013 close to major urban populations in Sydney (New South Wales), Hobart (Tasmania) and Adelaide (South Australia). The samples were analysed for their total Pb concentration and Pb isotopic composition to determine the sources of Pb and the extent, if any, of industrial contamination and its recycling into the ecosystem. Median ash concentrations (23mg/kg) released from a wildfire close to Australia's largest city, Sydney, exceeded the median ash Pb concentrations from wildfires from the less populated locations of Hobart, Adelaide and NSW Central Coast. Lead isotopic compositions of Duffys Forest wildfire ash demonstrate that anthropogenic inputs from legacy leaded petrol depositions were the predominant source of contamination. Despite the cessation of leaded petrol use in Australia in 2002, historic petrol Pb deposits continue to be a substantial source of contamination in ash: petrol Pb contributed 35% of the Pb in the Woy Woy ash, 73% in Duffys Forest ash, 39% in Forcett ash and 5% in Cherryville ash. The remobilisation of legacy industrial Pb depositions by wildfires in ash results in it being a persistent and problematic contaminant in contemporary environmental systems because of its known toxicity. Copyright © 2017 Elsevier B.V. All rights reserved.

Volcanic Ash Data Assimilation System for Atmospheric Transport Model

NASA Astrophysics Data System (ADS)

Ishii, K.; Shimbori, T.; Sato, E.; Tokumoto, T.; Hayashi, Y.; Hashimoto, A.

2017-12-01

The Japan Meteorological Agency (JMA) has two operations for volcanic ash forecasts, which are Volcanic Ash Fall Forecast (VAFF) and Volcanic Ash Advisory (VAA). In these operations, the forecasts are calculated by atmospheric transport models including the advection process, the turbulent diffusion process, the gravitational fall process and the deposition process (wet/dry). The initial distribution of volcanic ash in the models is the most important but uncertain factor. In operations, the model of Suzuki (1983) with many empirical assumptions is adopted to the initial distribution. This adversely affects the reconstruction of actual eruption plumes.We are developing a volcanic ash data assimilation system using weather radars and meteorological satellite observation, in order to improve the initial distribution of the atmospheric transport models. Our data assimilation system is based on the three-dimensional variational data assimilation method (3D-Var). Analysis variables are ash concentration and size distribution parameters which are mutually independent. The radar observation is expected to provide three-dimensional parameters such as ash concentration and parameters of ash particle size distribution. On the other hand, the satellite observation is anticipated to provide two-dimensional parameters of ash clouds such as mass loading, top height and particle effective radius. In this study, we estimate the thickness of ash clouds using vertical wind shear of JMA numerical weather prediction, and apply for the volcanic ash data assimilation system.

Comparing metabolomic profiles of Asian and North American ash species (genus Fraxinus) to investigate the basis for resistance to emerald ash borer

Treesearch

Darla French; Rick Meilan

2010-01-01

At present, North American ash (Fraxinus spp.) are under attack by the emerald ash borer (Agrilus planipennis Fairmaire; EAB), an invasive species native to eastern Asia. Interestingly, Asian ash species are comparatively resistant to this phloem-feeding insect.

Emerald ash borer aftermath forests: the future of ash ecosystems

Treesearch

Kathleen S. Knight; Daniel A. Herms; John Cardina; Robert Long; Kamal J.K. Gandhi; Catharine P. Herms

2011-01-01

The effects of emerald ash borer (EAB) (Agrilus planipennis) on forest ecosystems are being studied through a collaborative research program between the U.S. Forest Service and The Ohio State University. We are monitoring ash demographics, understory light availability, EAB population dynamics, native and non-native plants, and effects of ash...

Emerald ash borer infestation of ash stumps

Treesearch

Robert A. Haack; Toby R. Petrice

2005-01-01

The emerald ash borer (EAB), Agrilus planipennis Fairmaire (Buprestidae), was first found in North America in 2002. Eradication efforts are currently underway for this insect in both Canada and the United States. As part of the eradication program, thousands of ash trees are cut and chipped. Ash trees are known to produce stump sprouts, and therefore...

Feeding by emerald ash borer larvae induces systemic changes in black ash foliar chemistry

Treesearch

Yigen Chen; Justin G.A. Whitehill; Pierluigi Bonello; Therese M. Poland

2011-01-01

The exotic wood-boring pest, emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), has been threatening North American ash (Fraxinus spp.) resources, this being recognized since its first detection in Michigan, USA and Ontario, Canada in 2002. Ash trees are killed by larval feeding in the cambial region...

Attraction of the emerald ash borer to ash trees stressed by girdling, herbicide treatment, or wounding

Treesearch

Deborah McCullough; Therese Poland; David Cappaert

2009-01-01

New infestations of emerald ash borer, Agrilus planipennis Fairmaire, an invasive pest native to Asia, are difficult to detect until densities build and symptoms appear on affected ash (Fraxinus spp). We compared the attraction of A. planipennis to ash trees stressed by girdling (bark and phloem removed...

Environmental hazard of oil shale combustion fly ash.

PubMed

Blinova, Irina; Bityukova, Liidia; Kasemets, Kaja; Ivask, Angela; Käkinen, Aleksandr; Kurvet, Imbi; Bondarenko, Olesja; Kanarbik, Liina; Sihtmäe, Mariliis; Aruoja, Villem; Schvede, Hedi; Kahru, Anne

2012-08-30

The combined chemical and ecotoxicological characterization of oil shale combustion fly ash was performed. Ash was sampled from the most distant point of the ash-separation systems of the Balti and Eesti Thermal Power Plants in North-Eastern Estonia. The fly ash proved potentially hazardous for tested aquatic organisms and high alkalinity of the leachates (pH>10) is apparently the key factor determining its toxicity. The leachates were not genotoxic in the Ames assay. Also, the analysis showed that despite long-term intensive oil-shale combustion accompanied by considerable fly ash emissions has not led to significant soil contamination by hazardous trace elements in North-Eastern Estonia. Comparative study of the fly ash originating from the 'new' circulating fluidized bed (CFB) combustion technology and the 'old' pulverized-fired (PF) one showed that CFB fly ash was less toxic than PF fly ash. Thus, complete transfer to the 'new' technology will reduce (i) atmospheric emission of hazardous trace elements and (ii) fly ash toxicity to aquatic organisms as compared with the 'old' technology. Copyright © 2012 Elsevier B.V. All rights reserved.

Physical-durable performance of concrete incorporating high loss on ignition-fly ash

NASA Astrophysics Data System (ADS)

Huynh, Trong-Phuoc; Ngo, Si-Huy; Hwang, Chao-Lung

2018-04-01

This study investigates the feasibility of using raw fly ash with a high loss on ignition in concrete. The fly ash-free concrete samples were prepared with different water-to-binder (w/b) ratios of 0.35, 0.40, and 0.45, whereas the fly ash concrete samples were prepared with a constant w/b of 0.40 and with various fly ash contents (10%, 20%, and 30%) as a cement substitution. The physical properties and durability performance of the concretes were evaluated through fresh concrete properties, compressive strength, strength efficiency of cement, ultrasonic pulse velocity, and resistance to sulfate attack. Test results show that the w/b ratio affected the concrete properties significantly. The incorporation of fly ash increased the workability and reduced the unit weight of fresh concrete. In addition, the fly ash concrete samples containing up to 20% fly ash exhibited an improved strength at long-term ages. Further, all of the fly ash concrete samples showed a good durability performance with ultrasonic pulse velocity value of greater than 4100 m/s and a comparable sulfate resistance to the no-fly ash concrete.

Assessing fly ash treatment: remediation and stabilization of heavy metals.

PubMed

Lima, A T; Ottosen, Lisbeth M; Ribeiro, Alexandra B

2012-03-01

Fly ashes from Municipal Solid Waste (MSW), straw (ST) and co-combustion of wood (CW) are here analyzed with the intent of reusing them. Two techniques are assessed, a remediation technique and a solidification/stabilization one. The removal of heavy metals from fly ashes through the electrodialytic process (EDR) has been tried out before. The goal of removing heavy metals has always been the reuse of fly ash, for instance in agricultural fields (BEK). The best removal rates are here summarized and some new results have been added. MSW fly ashes are still too hazardous after treatment to even consider application to the soil. ST ash is the only residue that gets concentrations low enough to be reused, but its fertilizing value might be questioned. An alternative reuse for the three ashes is here preliminary tested, the combination of fly ash with mortar. Fly ashes have been substituted by cement fraction or aggregate fraction. Surprisingly, better compressive strengths were obtained by replacing the aggregate fraction. CW ashes presented promising results for the substitution of aggregate in mortar and possibly in concrete. Copyright © 2010 Elsevier Ltd. All rights reserved.

Physical and Chemical Properties of Coal Bottom Ash (CBA) from Tanjung Bin Power Plant

NASA Astrophysics Data System (ADS)

Izzati Raihan Ramzi, Nurul; Shahidan, Shahiron; Zulkhairi Maarof, Mohamad; Ali, Noorwirdawati

2016-11-01

The objective of this study is to determine the physical and chemical characteristics of Coal Bottom Ash (CBA) obtained from Tanjung Bin Power Plant Station and compare them with the characteristics of natural river sand (as a replacement of fine aggregates). Bottom ash is the by-product of coal combustion during the electricity generating process. However, excess bottom ash production due to the high production of electricity in Malaysia has caused several environmental problems. Therefore, several tests have been conducted in order to determine the physical and chemical properties of bottom ash such as specific gravity, density, particle size distribution, Scanning Electron Microscopic (SEM) and X- Ray Fluorescence (XRF) in the attempt to produce sustainable material from waste. The results indicated that the natural fine aggregate and coal bottom ash have very different physical and chemical properties. Bottom ash was classified as Class C ash. The porous structure, angular and rough texture of bottom ash affected its specific gravity and particle density. From the tests, it was found that bottom ash is recommended to be used in concrete as a replacement for fine aggregates.

Combustion of Biosolids in a Bubbling Fluidized Bed, Part 1: Main Ash-Forming Elements and Ash Distribution with a Focus on Phosphorus.

PubMed

Skoglund, Nils; Grimm, Alejandro; Ohman, Marcus; Boström, Dan

2014-02-20

This is the first in a series of three papers describing combustion of biosolids in a 5-kW bubbling fluidized bed, the ash chemistry, and possible application of the ash produced as a fertilizing agent. This part of the study aims to clarify whether the distribution of main ash forming elements from biosolids can be changed by modifying the fuel matrix, the crystalline compounds of which can be identified in the raw materials and what role the total composition may play for which compounds are formed during combustion. The biosolids were subjected to low-temperature ashing to investigate which crystalline compounds that were present in the raw materials. Combustion experiments of two different types of biosolids were conducted in a 5-kW benchscale bubbling fluidized bed at two different bed temperatures and with two different additives. The additives were chosen to investigate whether the addition of alkali (K 2 CO 3 ) and alkaline-earth metal (CaCO 3 ) would affect the speciation of phosphorus, so the molar ratios targeted in modified fuels were P:K = 1:1 and P:K:Ca = 1:1:1, respectively. After combustion the ash fractions were collected, the ash distribution was determined and the ash fractions were analyzed with regards to elemental composition (ICP-AES and SEM-EDS) and part of the bed ash was also analyzed qualitatively using XRD. There was no evidence of zeolites in the unmodified fuels, based on low-temperature ashing. During combustion, the biosolid pellets formed large bed ash particles, ash pellets, which contained most of the total ash content (54%-95% (w/w)). This ash fraction contained most of the phosphorus found in the ash and the only phosphate that was identified was a whitlockite, Ca 9 (K,Mg,Fe)(PO 4 ) 7 , for all fuels and fuel mixtures. With the addition of potassium, cristobalite (SiO 2 ) could no longer be identified via X-ray diffraction (XRD) in the bed ash particles and leucite (KAlSi 2 O 6 ) was formed. Most of the alkaline-earth metals calcium and magnesium were also found in the bed ash. Both the formation of aluminum-containing alkali silicates and inclusion of calcium and magnesium in bed ash could assist in preventing bed agglomeration during co-combustion of biosolids with other renewable fuels in a full-scale bubbling fluidized bed.

Combustion of Biosolids in a Bubbling Fluidized Bed, Part 1: Main Ash-Forming Elements and Ash Distribution with a Focus on Phosphorus

PubMed Central

2014-01-01

This is the first in a series of three papers describing combustion of biosolids in a 5-kW bubbling fluidized bed, the ash chemistry, and possible application of the ash produced as a fertilizing agent. This part of the study aims to clarify whether the distribution of main ash forming elements from biosolids can be changed by modifying the fuel matrix, the crystalline compounds of which can be identified in the raw materials and what role the total composition may play for which compounds are formed during combustion. The biosolids were subjected to low-temperature ashing to investigate which crystalline compounds that were present in the raw materials. Combustion experiments of two different types of biosolids were conducted in a 5-kW benchscale bubbling fluidized bed at two different bed temperatures and with two different additives. The additives were chosen to investigate whether the addition of alkali (K2CO3) and alkaline-earth metal (CaCO3) would affect the speciation of phosphorus, so the molar ratios targeted in modified fuels were P:K = 1:1 and P:K:Ca = 1:1:1, respectively. After combustion the ash fractions were collected, the ash distribution was determined and the ash fractions were analyzed with regards to elemental composition (ICP-AES and SEM-EDS) and part of the bed ash was also analyzed qualitatively using XRD. There was no evidence of zeolites in the unmodified fuels, based on low-temperature ashing. During combustion, the biosolid pellets formed large bed ash particles, ash pellets, which contained most of the total ash content (54%–95% (w/w)). This ash fraction contained most of the phosphorus found in the ash and the only phosphate that was identified was a whitlockite, Ca9(K,Mg,Fe)(PO4)7, for all fuels and fuel mixtures. With the addition of potassium, cristobalite (SiO2) could no longer be identified via X-ray diffraction (XRD) in the bed ash particles and leucite (KAlSi2O6) was formed. Most of the alkaline-earth metals calcium and magnesium were also found in the bed ash. Both the formation of aluminum-containing alkali silicates and inclusion of calcium and magnesium in bed ash could assist in preventing bed agglomeration during co-combustion of biosolids with other renewable fuels in a full-scale bubbling fluidized bed. PMID:24678140

Peak exposures to main components of ash and gaseous diesel exhausts in closed and open ash loading stations at biomass-fuelled power plants.

PubMed

Laitinen, Juha; Koponen, Hanna; Sippula, Olli; Korpijärvi, Kirsi; Jumpponen, Mika; Laitinen, Sirpa; Aatamila, Marjaleena; Tissari, Jarkko; Karhunen, Tommi; Ojanen, Kari; Jokiniemi, Jorma; Korpinen, Leena

2017-10-01

Fly and bottom ashes are collected at power plants to reduce the environmental effects of energy production. However, handling the ashes causes health problems for operators, maintenance workers and truck drivers at the power plants. Hence, we evaluated ash loaders' peak inhalation exposures to the chemical components of ash and diesel exhausts in open and closed ash loading stations at biomass-fuelled combined heat and power plants. We also carried out chemical and morphological analyses of the ashes to evaluate their health hazard potential in order to find practical technical measures to reduce workers' exposure. On the basis of X-ray diffraction analyses, the main respirable crystalline ash compounds were SiO 2 , CaSO 4 , CaO, Ca 2 Al 2 SiO 7 , NaCl and Ca 3 Al 2 O 6 in the fly ashes and SiO 2 , KAlSi 3 O 8 , NaAlSi 3 O 8 and Ca 2 Al 2 SiO 7 in the bottom ashes. The short-term exposure levels of respirable crystalline silica, inhalable inorganic dust, Cr, Mn, Ni and nitric oxide exceeded their Finnish eight hours occupational exposure limit values in the closed ash loading station. According to our observations, more attention should be paid to the ash-moistening process, the use of tank trucks instead of open cassette flatbed trucks, and the sealing of the loading line from the silo to the truck which would prevent spreading the ash into the air. The idling time of diesel trucks should also be limited, and ash loading stations should be equipped with exhaust gas ventilators. If working conditions make it impossible to keep to the OEL values, workers must use respirators and protect their eyes and skin. Copyright © 2017 Elsevier Ltd. All rights reserved.

EVALUATION OF THE EFFECTS OF COAL FLY ASH AMENDMENTS ON THE TOXICITY OF A CONTAMINATED MARINE SEDIMENT

PubMed Central

Burgess, Robert M.; Perron, Monique M.; Friedman, Carey L.; Suuberg, Eric M.; Pennell, Kelly G.; Cantwell, Mark G.; Pelletier, Marguerite C.; Ho, Kay T.; Serbst, Jonathan R.; Ryba, Stephan A.

2013-01-01

Approaches for cleaning-up contaminated sediments range from dredging to in situ treatment. In the present report, we discuss the effects of amending reference and contaminated sediments with coal fly ash to reduce the bioavailability and toxicity of a field sediment contaminated with polycyclic aromatic hydrocarbons (PAHs). Six fly ashes and a coconut charcoal were evaluated in 7 d whole sediment toxicity tests with a marine amphipod (Ampelisca abdita) and mysid (Americamysis bahia). Fly ashes with high carbon content and the coconut charcoal showed proficiency at reducing toxicity. Some of the fly ashes demonstrated toxicity in the reference treatments. It is suspected that some of this toxicity is related to the presence of ammonia associated with fly ashes as a result of post-oxidation treatment to reduce nitrous oxides emissions. Relatively simple methods exist to remove ammonia from fly ash prior to use and fly ashes with low ammonia content are available. Fly ashes were also shown to effectively reduce overlying water concentrations of several PAHs. There was no evidence of the release of the metals cadmium, copper, nickel or lead from the fly ashes. A preliminary 28 d polychaete bioaccumulation study with one of the high carbon fly ashes and a reference sediment was also performed. Although preliminary, there was no evidence of adverse effects to worm growth or lipid content, or the accumulation of PAHs or mercury from exposure to the fly ash. These data show fly ashes with high carbon contents may represent viable remedial materials for reducing the bioavailability of organic contaminants in sediments. PMID:18717615

Ash reduction strategies in corn stover facilitated by anatomical and size fractionation

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

Lacey, Jeffrey A.; Emerson, Rachel M.; Thompson, David N.

There is growing interest internationally to produce fuels from renewable biomass resources. Inorganic components of biomass feedstocks, referred to collectively as ash, damage equipment and decrease yields in thermal conversion processes, and decrease feedstock value for biochemical conversion processes. Decreasing the ash content of feedstocks improves conversion efficiency and lowers process costs. Because physiological ash is unevenly distributed in the plant, mechanical processes can be used to separate fractions of the plant based on ash content. This study focuses on the ash separation that can be achieved by separating corn stover by particle size and anatomical fraction. Baled corn stovermore » was hand-separated into anatomical fractions, ground to <19.1 mm, and size separated using six sieves ranging from 9.5 to 0.150 mm. Size fractions were analyzed for total ash content and ash composition. Particle size distributions observed for the anatomical fractions varied considerably. Cob particles were primarily 2.0 mm or greater, while most of the sheath and husk particles were 2.0 mm and smaller. Particles of leaves greater than 0.6 mm contained the greatest amount of total ash, ranging from approximately 8 to 13% dry weight of the total original material, while the fractions with particles smaller than 0.6 mm contained less than 2% of the total ash of the original material. As a result, based on the overall ash content and the elemental ash, specific anatomical and size fractions can be separated to optimize the feedstocks being delivered to biofuels conversion processes and minimize the need for more expensive ash reduction treatments.« less

Ash reduction strategies in corn stover facilitated by anatomical and size fractionation

DOE PAGES

Lacey, Jeffrey A.; Emerson, Rachel M.; Thompson, David N.; ...

2016-04-22

There is growing interest internationally to produce fuels from renewable biomass resources. Inorganic components of biomass feedstocks, referred to collectively as ash, damage equipment and decrease yields in thermal conversion processes, and decrease feedstock value for biochemical conversion processes. Decreasing the ash content of feedstocks improves conversion efficiency and lowers process costs. Because physiological ash is unevenly distributed in the plant, mechanical processes can be used to separate fractions of the plant based on ash content. This study focuses on the ash separation that can be achieved by separating corn stover by particle size and anatomical fraction. Baled corn stovermore » was hand-separated into anatomical fractions, ground to <19.1 mm, and size separated using six sieves ranging from 9.5 to 0.150 mm. Size fractions were analyzed for total ash content and ash composition. Particle size distributions observed for the anatomical fractions varied considerably. Cob particles were primarily 2.0 mm or greater, while most of the sheath and husk particles were 2.0 mm and smaller. Particles of leaves greater than 0.6 mm contained the greatest amount of total ash, ranging from approximately 8 to 13% dry weight of the total original material, while the fractions with particles smaller than 0.6 mm contained less than 2% of the total ash of the original material. As a result, based on the overall ash content and the elemental ash, specific anatomical and size fractions can be separated to optimize the feedstocks being delivered to biofuels conversion processes and minimize the need for more expensive ash reduction treatments.« less

Utilization of coal fly ash in solidification of liquid radioactive waste from research reactor.

PubMed

Osmanlioglu, Ahmet Erdal

2014-05-01

In this study, the potential utilization of fly ash was investigated as an additive in solidification process of radioactive waste sludge from research reactor. Coal formations include various percentages of natural radioactive elements; therefore, coal fly ash includes various levels of radioactivity. For this reason, fly ashes have to be evaluated for potential environmental implications in case of further usage in any construction material. But for use in solidification of radioactive sludge, the radiological effects of fly ash are in the range of radioactive waste management limits. The results show that fly ash has a strong fixing capacity for radioactive isotopes. Specimens with addition of 5-15% fly ash to concrete was observed to be sufficient to achieve the target compressive strength of 20 MPa required for near-surface disposal. An optimum mixture comprising 15% fly ash, 35% cement, and 50% radioactive waste sludge could provide the solidification required for long-term storage and disposal. The codisposal of radioactive fly ash with radioactive sludge by solidification decreases the usage of cement in solidification process. By this method, radioactive fly ash can become a valuable additive instead of industrial waste. This study supports the utilization of fly ash in industry and the solidification of radioactive waste in the nuclear industry.

Evaluation of the Biotoxicity of Tree Wood Ashes in Zebrafish Embryos.

PubMed

Consigli, Veronica; Guarienti, Michela; Bilo, Fabjola; Benassi, Laura; Depero, Laura E; Bontempi, Elza; Presta, Marco

2016-10-01

Ashes derived from biomass combustion and used as soil fertilizers can generate negative environmental and human health risks, related to leaching of heavy metals and other putative toxic elements. Tree wood ash composition may vary depending on geographical location and surrounding industrial processes. In this study, we evaluated the biotoxicity of lixiviated tree wood ash samples from trees of the Ash (Fraxinus), Cherry (Pronus), Hazel (Corylus), and Black locust (Robinia) genus collected in an industrialized region in Northern Italy. Elemental chemical analysis of the samples was performed by total reflection X-ray fluorescence technique and their biotoxicity was assessed in zebrafish (Danio rerio) embryos. Ashes from Ash, Cherry, and Hazel trees, but not Black locust trees, had a high concentration of heavy metals and other putative toxic elements. Accordingly, a dose-dependent increase in mortality rate and morphological and teratogenic defects was observed in zebrafish embryos treated with lixiviated Ash, Cherry, and Hazel tree wood samples, whereas the toxicity of Black locust tree wood ashes was negligible. In conclusion, lixiviated wood ashes from different plants show a different content of toxic elements that correlate with their biotoxic effects on zebrafish embryos. Tree wood ashes derived from biomass combustion may represent a potential risk for the environment and human health.

High-performance self-compacting concrete with the use of coal burning waste

NASA Astrophysics Data System (ADS)

Bakhrakh, Anton; Solodov, Artyom; Naruts, Vitaly; Larsen, Oksana; Alimov, Lev; Voronin, Victor

2017-10-01

Today, thermal power plants are the main producers of energy in Russia. Most of thermal power plants use coal as fuel. The remaining waste of coal burning is ash, In Russia ash is usually kept at dumps. The amount of utilized ash is quite small, less than 13%. Meanwhile, each ash dump is a local ecological disaster. Ash dumps take a lot of place and destroy natural landscape. The use of fly ash in building materials can solve the problem of fly ash dumps in Russia. A lot of papers of scientists are devoted to the use of fly ash as filler in concrete. The main advantage of admixing fly ash in concrete is decrease of amount of used cement. This investigation was held to find out if it is possible to utilize fly ash by its use in high amounts in self-compacting concrete. During experiments three mixtures of SCC with different properties were obtained. The first one is experimental and shows the possibility of obtaining SCC with high compressive strength with 60% of fly ash from the mass of cement. Two other mixtures were optimized with the help of the math planning method to obtain high 7-day and 28-day high compressive strength.

Reuse of Coconut Shell, Rice Husk, and Coal Ash Blends in Geopolymer Synthesis

NASA Astrophysics Data System (ADS)

Walmiki Samadhi, Tjokorde; Wulandari, Winny; Prasetyo, Muhammad Iqbal; Rizki Fernando, Muhammad

2017-10-01

Mixtures of biomass and coal ashes are likely to be produced in increasing volume as biomass-based energy production is gaining importance in Indonesia. This work highlights the reuse of coconut shell ash (CSA), rice husk ash (RHA), and coal fly ash (FA) for geopolymer synthesis by an activator solution containing concentrated KOH and Na2SiO3. Ash blend compositions are varied according to a simplex-centroid mixture experimental design. Activator to ash mass ratios are varied from 0.8 to 2.0, the higher value being applied for ash compositions with higher Si/Al ratio. The impact of ash blend composition on early strength is adequately modeled by an incomplete quadratic mixture model. Overall, the ashes can produce geopolymer mortars with an early strength exceeding the Indonesian SNI 15-2049-2004 standard minimum value of 2.0 MPa. Good workability of the geopolymer is indicated by their initial setting times which are longer than the minimum value of 45 mins. Geopolymers composed predominantly of RHA composition exhibit poor strength and excessive setting time. FTIR spectroscopy confirms the geopolymerization of the ashes by the shift of the Si-O-Si/Al asymmetric stretching vibrational mode. Overall, these results point to the feasibility of geopolymerization as a reuse pathway for biomass combustion waste.

Characteristics of fly ashes from full-scale coal-fired power plants and their relationship to mercury adsorption

USGS Publications Warehouse

Lu, Y.; Rostam-Abadi, M.; Chang, R.; Richardson, C.; Paradis, J.

2007-01-01

Nine fly ash samples were collected from the particulate collection devices (baghouse or electrostatic precipitator) of four full-scale pulverized coal (PC) utility boilers burning eastern bituminous coals (EB-PC ashes) and three cyclone utility boilers burning either Powder River Basin (PRB) coals or PRB blends,(PRB-CYC ashes). As-received fly ash samples were mechanically sieved to obtain six size fractions. Unburned carbon (UBC) content, mercury content, and Brunauer-Emmett-Teller (BET)-N2 surface areas of as-received fly ashes and their size fractions were measured. In addition, UBC particles were examined by scanning electron microscopy, high-resolution transmission microscopy, and thermogravimetry to obtain information on their surface morphology, structure, and oxidation reactivity. It was found that the UBC particles contained amorphous carbon, ribbon-shaped graphitic carbon, and highly ordered graphite structures. The mercury contents of the UBCs (Hg/UBC, in ppm) in raw ash samples were comparable to those of the UBC-enriched samples, indicating that mercury was mainly adsorbed on the UBC in fly ash. The UBC content decreased with a decreasing particle size range for all nine ashes. There was no correlation between the mercury and UBC contents of different size fractions of as-received ashes. The mercury content of the UBCs in each size fraction, however, generally increased with a decreasing particle size for the nine ashes. The mercury contents and surface areas of the UBCs in the PRB-CYC ashes were about 8 and 3 times higher than UBCs in the EB-PC ashes, respectively. It appeared that both the particle size and surface area of UBC could contribute to mercury capture. The particle size of the UBC in PRB-CYC ash and thus the external mass transfer was found to be the major factor impacting the mercury adsorption. Both the particle size and surface reactivity of the UBC in EB-PC ash, which generally had a lower carbon oxidation reactivity than the PRB-PC ashes, appeared to be important for the mercury adsorption. ?? 2007 American Chemical Society.

Biomass fly ash incorporation in cement based materials =

NASA Astrophysics Data System (ADS)

Rajamma, Rejini

In recent years, pressures on global environment and energy security have led to an increasing demand on renewable energy sources, and diversification of Europe's energy supply. Among these resources the biomass could exert an important role, since it is considered a renewable and CO2 neutral energy resource once the consumption rate is lower than the growth rate, and can potentially provide energy for heat, power and transports from the same installation. Currently, most of the biomass ash produced in industrial plants is either disposed of in landfill or recycled on agricultural fields or forest, and most times this goes on without any form of control. However, considering that the disposal cost of biomass ashes are raising, and that biomass ash volumes are increasing worldwide, a sustainable ash management has to be established. The main objective of the present study is the effect of biomass fly ashes in cement mortars and concretes in order to be used as a supplementary cementitious material. The wastes analyzed in the study were collected from the fluidized bed boilers and grate boilers available in the thermal power plants and paper pulp plants situated in Portugal. The physical as well as chemical characterisations of the biomass fly ashes were investigated. The cement was replaced by the biomass fly ashes in 10, 20 and 30% (weight %) in order to investigate the fresh properties as well as the hardened properties of biomass fly ash incorporated cement mortar and concrete formulations. Expansion reactions such as alkali silica reaction (ASR), sulphate attack (external and internal) were conducted in order to check the durability of the biomass fly ash incorporated cement mortars and concretes. Alternative applications such as incorporation in lime mortars and alkali activation of the biomass fly ashes were also attempted. The biomass fly ash particles were irregular in shape and fine in nature. The chemical characterization revealed that the biomass fly ashes were similar to a class C fly ash. The mortar results showed a good scope for biomass fly ashes as supplementary cementitious materials in lower dosages (<20%). The poor workability, concerns about the organic content, alkalis, chlorides and sulphates stand as the reasons for preventing the use of biomass fly ash in high content in the cement mortars. The results obtained from the durability tests have shown a clear reduction in expansion for the biomass fly ash mortars/concretes and the binder blend made with biomass fly ash (20%) and metakaolin (10%) inhibited the ASR reaction effectively. The biomass fly ash incorporation in lime mortars did not improve the mortar properties significantly though the carbonation was enhanced in the 15-20% incorporation. The biomass fly ash metakaolin blend worked well in the alkali activated complex binder application also. Portland cement free binders (with 30-40 MPa compressive strength) were obtained on the alkali activation of biomass fly ashes (60-80%) blended with metakaolin (20-40%).

Potential species replacements for black ash (Fraxinus nigra) at the confluence of two threats: Emerald ash borer and a changing climate

Treesearch

Louis Iverson; Kathleen S. Knight; Anantha Prasad; Daniel A. Herms; Stephen Matthews; Matthew Peters; Annemarie Smith; Diane M. Hartzler; Robert Long; John Almendinger

2015-01-01

The emerald ash borer (Agrilus planipennis; EAB) is causing widespread mortality of ash (Fraxinus spp.) and climate change is altering habitats of tree species throughout large portions of North America. Black ash (F. nigra), a moist-soil species common in the Northwoods of Minnesota, Wisconsin, and...

Distribution of trunk-injected 14C-imidacloprid in ash trees and effects on emerald ash borer (Coleoptera: Buprestidae) adults

Treesearch

David Mota-Sánchez; Bert M. Cregg; Deborah G. McCullough; Therese M. Poland; Robert M. Hollingworth

2009-01-01

The emerald ash borer (EAB), Agrilus planipennis (Coleoptera: Buprestidae) is a destructive exotic pest of North American ash (Fraxinus sp.) trees. Trunk injection of imidacloprid is commonly used to protect landscape ash trees from A. planipennis damage. Efficacy can vary and little is known about the...

Source water contributions and hydrologic responses to simulated emerald ash borer infestations in depressional black ash wetlands

Treesearch

Matthew J. Van Grinsven; Joseph P. Shannon; Joshua C. Davis; Nicholas W. Bolton; Joseph W. Wagenbrenner; Randall K. Kolka; Thomas Grant Pypker

2017-01-01

Forested wetlands dominated by black ash (Fraxinus nigra) are currently threatened by the rapid expansion of the exotic emerald ash borer (EAB) (Agrilus planipennis, Coleoptera: Buprestidae) in North America, and very little is known about the hydrology and ecology of black ash wetlands. The ecohydrological response of...

Physiological responses of emerald ash borer larvae to feeding on different ash species reveal putative resistance mechanisms and insect counter-adaptations

Treesearch

C.M. Rigsby; D.N. Showalter; D.A. Herms; J.L. Koch; P. Bonello; D. Cipollini

2015-01-01

Emerald ash borer, Agrilus planipennis Fairmaire, an Asian wood-boring beetle, has devastated ash (Fraxinus spp.) trees in North American forests and landscapes since its discovery there in 2002. In this study, we collected living larvae from EAB-resistant Manchurian ash (Fraxinus mandschurica), and susceptible...

Survey for tolerance to emerald ash borer within North American ash species

Treesearch

Jennifer L. Koch; Mary E. Mason; David W. Carey; Kathleen Knight; Therese Poland; Daniel A. Herms

2010-01-01

Since the discovery of the emerald ash borer (EAB) near Detroit, MI, in 2002, more than 40 million ash trees have been killed and another 7.5 billion are at risk in the United States. When the EAB outbreak was initially discovered, our native ash species appeared to have no resistance to the pest.

Synthetic studies toward 7-epi-sesquithujene, bicyclic sesquiterpene antennally active to emerald ash borer

USDA-ARS?s Scientific Manuscript database

Emerald ash borer, Agrilus planipennis, is an invasive beetle that has been causing extensive mortality of ash trees since arriving in North America in 2002. 7-epi-Sesquithujene (1) is produced by stressed ash and elicits a strong EAD response on the emerald ash borer antennae. In the course of ma...

Large-scale reintroduction of ash

Treesearch

Ronald. Overton

2010-01-01

No strategies currently exist for reintroducing ash; progression of emerald ash borer (EAB) through the eastern United States is likely to be a decades-long process, and extirpation of ash from this area is likely to take even longer. Reintroduction of ash into areas where it has been extirpated by EAB will require addressing technical issues as well as social and...

Emerald ash borer biocontrol in ash saplings: The potential for early stage recovery of North American ash trees

Treesearch

Jian J. Duan; Leah S. Bauer; Roy G. Van Driesche

2017-01-01

In many parts of North America, ash (Fraxinus) stands have been reduced by the emerald ash borer (Agrilus planipennis) invasion to a few surviving mature trees, saplings, basal sprouts, and seedlings. Without a soil seed bank for Fraxinus spp., tree recovery will require survival and maturation of these...

The Role of Biocontrol of Emerald Ash Borer in Protecting Ash Regeneration after Invasion

USDA-ARS?s Scientific Manuscript database

Emerald ash borer (EAB) is an invasive Asian beetle that is destroying ash in forests over much of eastern North America because of the high susceptibility of our native ash and a lack of effective natural enemies. To increase mortality of EAB larvae and eggs, the USDA (FS, ARS and APHIS) is carryin...

Evaluation of log submergence to control EAB and preserve black ash for native American basketry

Treesearch

Therese M. Poland; Damon J. Crook; Tina M. Ciaramitaro

2011-01-01

Many Native American cultures use black ash, Fraxinus nigra, for basket-making because its ring-porous wood allows the annual layers of xylem to be easily separated. The emerald ash borer (EAB, Agrilus planipennis) is threatening North America's ash resource including black ash, and a centuries-old native art form. Native...

Availability of residual phosphorus from broiler litter ash and layer manure ash amended soil for Paspalum vaginatum uptake

USDA-ARS?s Scientific Manuscript database

It has been hypothesized by several scientists that poultry litter ash could be used as a slow releasing phosphorus fertilizer that will become available over time. To test this hypothesis, a greenhouse study was conducted using a broiler litter ash, layer manure ash and calcium phosphate to determ...

Attraction of the emerald ash borer to ash trees stressed by girdling, herbicide treatment, or wounding

Treesearch

Deborah G. McCullough; Therese M. Poland; David Cappaert

2009-01-01

New infestations of emerald ash borer, Agrilus planipennis Fainnaire, an invasive pest native to Asia, are difficult to detect until densities build and symptoms appear on affected ash (Fraxinus spp). We compared the attraction of A. planipennis to ash trees stressed by girdling(bark and phloem removed from a 15...

Fly ash in landfill top covers - a review.

PubMed

Brännvall, E; Kumpiene, J

2016-01-01

Increase of energy recovery from municipal solid waste by incineration results in the increased amounts of incineration residues, such as fly ash, that have to be taken care of. Material properties should define whether fly ash is a waste or a viable resource to be used for various applications. Here, two areas of potential fly ash application are reviewed: the use of fly ash in a landfill top cover either as a liner material or as a soil amendment in vegetation layer. Fly ashes from incineration of three types of fuel are considered: refuse derived fuel (RDF), municipal solid waste incineration (MSWI) and biofuel. Based on the observations, RDF and MSWI fly ash is considered as suitable materials to be used in a landfill top cover liner. Whereas MSWI and biofuel fly ashes based on element availability for plant studies, could be considered suitable for the vegetation layer of the top cover. Responsible application of MSWI ashes is, however, warranted in order to avoid element accumulation in soil and elevation of background values over time.

Physical and biological studies of coal and oil fly ash.

PubMed Central

Fisher, G L; McNeill, K L; Prentice, B A; McFarland, A R

1983-01-01

Studies were performed to compare the physical and chemical characteristics and the in vitro macrophage cytotoxicity of oil and coal fly ash. Sampling methodology was developed to collect size-fractionated particulate matter from the smokestack of either a coal-fired or an oil-fired power plant. Morphological studies demonstrated particle heterogeneity, although most coal fly ash particles appeared to be spherical. Oil fly ash contained two major morphologies; nonopaque amorphous particles and opaque amorphous particles. Elemental analysis indicates that the coal ash is predominantly composed of aluminosilicate particles, while the oil ash is predominantly inorganic sulfates and carbonaceous particles. In vitro macrophage assays demonstrate that the finest coal fly ash particles are the most cytotoxic; the cytotoxicity is significantly less than that of alpha-quartz, the positive control particle. In contrast, the oil fly ash particles are more cytotoxic than quartz. The cytotoxicity of oil fly ash is due to soluble components, possibly vanadium salts. Images FIGURE 2. A FIGURE 2. B FIGURE 2. C FIGURE 2. D PMID:6641653

Experimental study on durability improvement of fly ash concrete with durability improving admixture.

PubMed

Quan, Hong-zhu; Kasami, Hideo

2014-01-01

In order to improve the durability of fly ash concrete, a series of experimental studies are carried out, where durability improving admixture is used to reduce drying shrinkage and improve freezing-thawing resistance. The effects of durability improving admixture, air content, water-binder ratio, and fly ash replacement ratio on the performance of fly ash concrete are discussed in this paper. The results show that by using durability improving admixture in nonair-entraining fly ash concrete, the compressive strength of fly ash concrete can be improved by 10%-20%, and the drying shrinkage is reduced by 60%. Carbonation resistance of concrete is roughly proportional to water-cement ratio regardless of water-binder ratio and fly ash replacement ratio. For the specimens cured in air for 2 weeks, the freezing-thawing resistance is improved. In addition, by making use of durability improving admixture, it is easier to control the air content and make fly ash concrete into nonair-entraining one. The quality of fly ash concrete is thereby optimized.

Eco-friendly fly ash utilization: potential for land application

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

Malik, A.; Thapliyal, A.

2009-07-01

The increase in demand for power in domestic, agricultural, and industrial sectors has increased the pressure on coal combustion and aggravated the problem of fly ash generation/disposal. Consequently the research targeting effective utilization of fly ash has also gained momentum. Fly ash has proved to be an economical substitute for expensive adsorbents as well as a suitable raw material for brick manufacturing, zeolite synthesis, etc. Fly ash is a reservoir of essential minerals but is deficient in nitrogen and phosphorus. By amending fly ash with soil and/or various organic materials (sewage sludge, bioprocess materials) as well as microbial inoculants likemore » mycorrhizae, enhanced plant growth can be realized. Based on the sound results of large scale studies, fly ash utilization has grown into prominent discipline supported by various internationally renowned organizations. This paper reviews attempts directed toward various utilization of fly ash, with an emphasis on land application of organic/microbial inoculants amended fly ash.« less

Pore Structure Characterization in Concrete Prepared with Carbonated Fly Ash

NASA Astrophysics Data System (ADS)

Sahoo, Sanjukta

2018-03-01

Carbon dioxide capture and storage (CCS) is a technique to address the global concern of continuously rising CO2 level in the atmosphere. Fly ash is considered as a suitable medium for CCS due to presence of metal oxides. The fly ash which has already sequestered carbon dioxide is referred to as carbonated fly ash. Recent research reveals better durability of concretes using carbonated fly ash as part replacement of cement. In the present research pore structure characterization of the carbonated fly ash concrete has been carried out. Mercury Intrusion porosimetry test has been conducted on control concrete and concrete specimens using fly ash and carbonated fly ash at replacement levels of 25% and 40%. The specimens have been water cured for 28 days and 90 days. It is observed that porosity reduction rate is more pronounced in carbonated fly ash concrete compared to control concrete at higher water curing age. Correlation analysis is also carried out which indicates moderately linear relationship between porosity % and pore distribution with particle size and water curing.

Testing exposure of a jet engine to a dilute volcanic-ash cloud

NASA Astrophysics Data System (ADS)

Guffanti, M.; Mastin, L. G.; Schneider, D. J.; Holliday, C. R.; Murray, J. J.

2013-12-01

An experiment to test the effects of volcanic-ash ingestion by a jet engine is being planned for 2014 by a consortium of U.S. Government agencies and engine manufacturers, under the auspices of NASA's Vehicle Integrated Propulsion Research Program. The experiment, using a 757-type engine, will be an on-ground, on-wing test carried out at Edwards Air Force Base, California. The experiment will involve the use of advanced jet-engine sensor technology for detecting and diagnosing engine health. A primary test objective is to determine the effect on the engine of many hours of exposure to ash concentrations (1 and 10 mg/cu m) representative of ash clouds many 100's to >1000 km from a volcanic source, an aviation environment of great interest since the 2010 Eyjafjallajökull, Iceland, eruption. A natural volcanic ash will be used; candidate sources are being evaluated. Data from previous ash/aircraft encounters, as well as published airborne measurements of the Eyjafjallajökull ash cloud, suggest the ash used should be composed primarily of glassy particles of andesitic to rhyolitic composition (SiO2 of 57-77%), with some mineral crystals, and a few tens of microns in size. Collected ash will be commercially processed less than 63 microns in size with the expectation that the ash particles will be further pulverized to smaller sizes in the engine during the test. For a nominally planned 80 hour test at multiple ash-concentration levels, the test will require roughly 500 kg of processed (appropriately sized) ash to be introduced into the engine core. Although volcanic ash clouds commonly contain volcanic gases such as sulfur dioxide, testing will not include volcanic gas or aerosol interactions as these present complex processes beyond the scope of the planned experiment. The viscous behavior of ash particles in the engine is a key issue in the experiment. The small glassy ash particles are expected to soften in the engine's hot combustion chamber, then stick to cooler parts of the turbine. Composition (primarily silica content) and dissolved water content, both of which affect the softening temperature of silicate melts, will be taken into account when evaluating candidate ash sources, although the practicalities of collecting, shipping, and processing a substantial amount of ash are a major decision factor in source selection.

Sulfate resistance of high calcium fly ash concrete

NASA Astrophysics Data System (ADS)

Dhole, Rajaram

Sulfate attack is one of the mechanisms which can cause deterioration of concrete. In general, Class C fly ash mixtures are reported to provide poor sulfate resistance. Fly ashes, mainly those belonging to the Class C, were tested as per the ASTM C 1012 procedure to evaluate chemical sulfate resistance. Overall the Class C fly ashes showed poor resistance in the sulfate environment. Different strategies were used in this research work to improve the sulfate resistance of Class C fly ash mixes. The study revealed that some of the strategies such as use of low W/CM (water to cementing materials by mass ratio), silica fume or ultra fine fly ash, high volumes of fly ash and, ternary or quaternary mixes with suitable supplementary cementing materials, can successfully improve the sulfate resistance of the Class C fly ash mixes. Combined sulfate attack, involving physical and chemical action, was studied using sodium sulfate and calcium sulfate solutions. The specimens were subjected to wetting-drying cycles and temperature changes. These conditions were found to accelerate the rate of degradation of concrete placed in a sodium sulfate environment. W/CM was found to be the main governing factor in providing sulfate resistance to mixes. Calcium sulfate did not reveal damage as a result of mainly physical action. Characterization of the selected fly ashes was undertaken by using SEM, XRD and the Rietveld analysis techniques, to determine the relation between the composition of fly ashes and resistance to sulfate attack. The chemical composition of glass represented on the ternary diagram was the main factor which had a significant influence on the sulfate resistance of fly ash mixtures. Mixes prepared with fly ashes containing significant amounts of vulnerable crystalline phases offered poor sulfate resistance. Comparatively, fly ash mixes containing inert crystalline phases such as quartz, mullite and hematite offered good sulfate resistance. The analysis of hydrated lime-fly ash pastes confirmed that fly ash mortar or concrete mixes forming more monosulfate than ettringite before exposure to sulfates would offer poor sulfate resistance and vice versa. During quantitative Rietveld analysis carried out for determining ettringite, monosulfate and gypsum formed in the fly ash pastes, it was observed that fly ash mixtures showing more ettringite after exposures to sulfates, give poor sulfate resistance. A good relationship between the amounts of ettringite formed and expansions of mortar specimens in the ASTM C 1012 test was found.

Publication sites productive uses of combustion ash

Science.gov Websites

Publication Sites Productive Uses of Combustion Ash For more information contact: e:mail: Public waste combustion ash in landfills. The new technology brief describes recent studies where ash was used

Lunar ash flows - Isothermal approximation.

NASA Technical Reports Server (NTRS)

Pai, S. I.; Hsieh, T.; O'Keefe, J. A.

1972-01-01

Suggestion of the ash flow mechanism as one of the major processes required to account for some features of lunar soil. First the observational background and the gardening hypothesis are reviewed, and the shortcomings of the gardening hypothesis are shown. Then a general description of the lunar ash flow is given, and a simple mathematical model of the isothermal lunar ash flow is worked out with numerical examples to show the differences between the lunar and the terrestrial ash flow. The important parameters of the ash flow process are isolated and analyzed. It appears that the lunar surface layer in the maria is not a residual mantle rock (regolith) but a series of ash flows due, at least in part, to great meteorite impacts. The possibility of a volcanic contribution is not excluded. Some further analytic research on lunar ash flows is recommended.

To fractionate municipal solid waste incineration bottom ash: Key for utilisation?

PubMed

Sormunen, Laura Annika; Rantsi, Riina

2015-11-01

For the past decade, the Finnish waste sector has increasingly moved from the landfilling of municipal solid waste towards waste incineration. New challenges are faced with the growing amounts of municipal solid waste incineration bottom ash, which are mainly landfilled at the moment. Since this is not a sustainable or a profitable solution, finding different utilisation applications for the municipal solid waste incineration bottom ash is crucial. This study reports a comprehensive analysis of bottom ash properties from one waste incineration plant in Finland, which was first treated with a Dutch bottom ash recovery technique called advanced dry recovery. This novel process separates non-ferrous and ferrous metals from bottom ash, generating mineral fractions of different grain sizes (0-2 mm, 2-5 mm, 5-12 mm and 12-50 mm). The main aim of the study was to assess, whether the advanced bottom ash treatment technique, producing mineral fractions of different grain sizes and therefore properties, facilitates the utilisation of municipal solid waste incineration bottom ash in Finland. The results were encouraging; the bottom ash mineral fractions have favourable behaviour against the frost action, which is especially useful in the Finnish conditions. In addition, the leaching of most hazardous substances did not restrict the utilisation of bottom ash, especially for the larger fractions (>5 mm). Overall, this study has shown that the advanced bottom ash recovering technique can be one solution to increase the utilisation of bottom ash and furthermore decrease its landfilling in Finland. © The Author(s) 2015.

Regional-scale input of dispersed and discrete volcanic ash to the Izu-Bonin and Mariana subduction zones

NASA Astrophysics Data System (ADS)

Scudder, Rachel P.; Murray, Richard W.; Schindlbeck, Julie C.; Kutterolf, Steffen; Hauff, Folkmar; McKinley, Claire C.

2014-11-01

We have geochemically and statistically characterized bulk marine sediment and ash layers at Ocean Drilling Program Site 1149 (Izu-Bonin Arc) and Deep Sea Drilling Project Site 52 (Mariana Arc), and have quantified that multiple dispersed ash sources collectively comprise ˜30-35% of the hemipelagic sediment mass entering the Izu-Bonin-Mariana subduction system. Multivariate statistical analyses indicate that the bulk sediment at Site 1149 is a mixture of Chinese Loess, a second compositionally distinct eolian source, a dispersed mafic ash, and a dispersed felsic ash. We interpret the source of these ashes as, respectively, being basalt from the Izu-Bonin Front Arc (IBFA) and rhyolite from the Honshu Arc. Sr-, Nd-, and Pb isotopic analyses of the bulk sediment are consistent with the chemical/statistical-based interpretations. Comparison of the mass accumulation rate of the dispersed ash component to discrete ash layer parameters (thickness, sedimentation rate, and number of layers) suggests that eruption frequency, rather than eruption size, drives the dispersed ash record. At Site 52, the geochemistry and statistical modeling indicates that Chinese Loess, IBFA, dispersed BNN (boninite from Izu-Bonin), and a dispersed felsic ash of unknown origin are the sources. At Site 1149, the ash layers and the dispersed ash are compositionally coupled, whereas at Site 52 they are decoupled in that there are no boninite layers, yet boninite is dispersed within the sediment. Changes in the volcanic and eolian inputs through time indicate strong arc-related and climate-related controls.

Potential of phosphorus recovery from sewage sludge and manure ash by thermochemical treatment.

PubMed

Havukainen, Jouni; Nguyen, Mai Thanh; Hermann, Ludwig; Horttanainen, Mika; Mikkilä, Mirja; Deviatkin, Ivan; Linnanen, Lassi

2016-03-01

All life forms require phosphorus (P), which has no substitute in food production. The risk of phosphorus loss from soil and limited P rock reserves has led to the development of recycling P from industrial residues. This study investigates the potential of phosphorus recovery from sewage sludge and manure ash by thermochemical treatment (ASH DEC) in Finland. An ASH DEC plant could receive 46-76 kt/a of sewage sludge ash to produce 51-85 kt/a of a P-rich product with a P2O5 content of 13-18%, while 320-750 kt/a of manure ash could be supplied to produce 350-830 kt/a of a P-rich product with a P content of 4-5%. The P2O5 potential in the total P-rich product from the ASH DEC process using sewage sludge and manure ash is estimated to be 25-47 kt/a, which is significantly more than the P fertilizer demand in Finland's agricultural industries. The energy efficiency of integrated incineration and the ASH DEC process is more dependent on the total solid content and the subsequent need for mechanical dewatering and thermal drying than on the energy required by the ASH DEC process. According to the results of this study, the treated sewage sludge and manure ash using the ASH DEC process represent significant potential phosphorus sources for P fertilizer production. Copyright © 2016 Elsevier Ltd. All rights reserved.

Synthesis of geopolymer from biomass-coal ash blends

NASA Astrophysics Data System (ADS)

Samadhi, Tjokorde Walmiki; Wulandari, Winny; Prasetyo, Muhammad Iqbal; Fernando, Muhammad Rizki; Purbasari, Aprilina

2017-09-01

Geopolymer is an environmentally attractive Portland cement substitute, owing to its lower carbon footprint and its ability to consume various aluminosilicate waste materials as its precursors. This work describes the development of geopolymer formulation based on biomass-coal ash blends, which is predicted to be the prevalent type of waste when biomass-based thermal energy production becomes mainstream in Indonesia. The ash blends contain an ASTM Class F coal fly ash (FA), rice husk ash (RHA), and coconut shell ash (CSA). A mixture of Na2SiO3 and concentrated KOH is used as the activator solution. A preliminary experiment identified the appropriate activator/ash mass ratio to be 2.0, while the activator Na2SiO3/KOH ratio varies from 0.8 to 2.0 with increasing ash blend Si/Al ratio. Both non-blended FA and CSA are able to produce geopolymer mortars with 7-day compressive strength exceeding the Indonesian national SNI 15-2049-2004 standard minimum value of 2.0 MPa stipulated for Portland cement mortars. Ash blends have to be formulated with a maximum RHA content of approximately 50 %-mass to yield satisfactory 7-day strength. No optimum ash blend composition is identified within the simplex ternary ash blend compositional region. The strength decreases with Si/Al ratio of the ash blends due to increasing amount of unreacted silicate raw materials at the end of the geopolymer hardening period. Overall, it is confirmed that CSA and blended RHA are feasible raw materials for geopolymer production..

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

Burgess, R.M.; Perron, M.M.; Friedman, C.L.

Approaches for cleaning up contaminated sediments range from dredging to in situ treatment. In this study, we discuss the effects of amending reference and contaminated sediments with coal fly ash to reduce the bioavailability and toxicity of a field sediment contaminated with polycyclic aromatic hydrocarbons (PAHs). Six fly ashes and a coconut charcoal were evaluated in 7-d whole sediment toxicity tests with a marine amphipod (Ampelisca abdita) and mysid (Americamysis bahia). Fly ashes with high carbon content and the coconut charcoal showed proficiency at reducing toxicity. Some of the fly ashes demonstrated toxicity in the reference treatments. It is suspectedmore » that some of this toxicity is related to the presence of ammonia associated with fly ashes as a result of postoxidation treatment to reduce nitrous oxide emissions. Relatively simple methods exist to remove ammonia from fly ash before use, and fly ashes with low ammonia content are available. Fly ashes were also shown to effectively reduce overlying water concentrations of several PAHs. No evidence was seen of the release of the metals cadmium, copper, nickel, or lead from the fly ashes. A preliminary 28-d polychaete bioaccumulation study with one of the high-carbon fly ashes and a reference sediment was also performed. Although preliminary, no evidence was seen of adverse effects to worm growth or lipid content or of accumulation of PAHs or mercury from exposure to the fly ash. These data show fly ashes with high carbon content could represent viable remedial materials for reducing the bioavailability of organic contaminants in sediments.« less

Effect of suspension property on granule morphology and compaction behavior

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

Hae-Weon Lee, Guesup Song, In-Sik Suk

1995-12-31

Granule morphology is an important factor during dry pressing, since it has great influences on die flowability, compaction ratio, and resulting green microstructure. Granule morphology and packing structure of ultrafine Si{sub 3}N{sub 4} particles in the granule were optimized during spray drying by adjusting the suspension structure. The particle packing structure of spray-dried granule was investigated with suspension structure. The effects of granule morphology and its particle packing structure on compaction and resultant sintering behavior were evaluated.

Using Kettle Lake Records to Date and Interpret Holocene Ash Deposition in Upper Cook Inlet, Anchorage, AK

NASA Astrophysics Data System (ADS)

Werner, A.; Kathan, K. M.; Kaufman, D. S.; Hancock, J. R.; Waythomas, C. F.; Wallace, K. L.

2004-12-01

Fourteen sediment cores recovered from three kettle lakes (Goose, Little Campbell and Lorraine) near Anchorage, AK were used to document and date Holocene volcanic ash deposition in the upper Cook Inlet area. Small lakes (<0.5 km2) with small (<1.5 km2), low relief (<50 m), and well-vegetated drainage areas were selected in order to minimize ash remobilization by mass wasting and fluvial processes. The resulting stratigraphic records are interpreted as primary terpha-fall stratigraphies. Relative to the surrounding lacustrine sediments, the ash layers exhibit low organic-matter content (as determined by loss-on-ignition, LOI), high magnetic susceptibility (MS), increased density (X-radiographs), and bubble-wall glass shards. Some ash layers are up to 1 cm thick (macrotephra) consisting of pure glass, some occur as light bands, while others (microtephra) can only be located using non-visual techniques (MS, LOI and X-radiography). The thinnest microtephras observed occur either as discrete (1 mm) layers or diffuse laminations composed of tephra mixed with ambient lake sediment. Forty-five AMS C-14 dates on terrestrial macro fossils were used to constrain sedimentation-rate models for the cores, and to assign absolute ages to ash units. Comparison of inferred tephra ages corroborates our intra and inter basin stratigraphic correlations (+/- 200 yrs) based on physical and MS stratigraphy. Ten out of 12 macrotephras can be confidently correlated among all three lakes, whereas, two of the prominent tephras occur in one basin but not in the others. This suggests subtle differences in ash plume extents or differences in tephra preservation between lakes. A total of 24 Holocene ash units (12 macro and 12 micro) have been recognized and dated in the Anchorage area, suggesting an ash-fall frequency of about 2.4/1000 yrs. By comparison, historical records suggest more frequent ash-fall events (120/1000 yrs). Our data indicate that, either the ash layers are not consistently preserved in the kettle basins, or more likely, these records lack the resolution to differentiate closely spaced ash-fall events. Core top stratigraphies support the latter interpretation: The 10-12 historically observed ash-fall events are represented by two diffuse zones in the upper 15 cm of the cores. As such, ash records from small kettle lakes should be regarded as conservative statements of ash deposition. Further, ash plumes can have narrow geographic distributions and ash-fall thicknesses can change markedly over short distances. Therefore distal ash-fall stratigraphies underestimate eruption frequencies.

Factors affecting the survival of ash (Fraxinus spp.) trees infested by emerald ash borer (Agrilus planipennis)

Treesearch

Kathleen S. Knight; John P. Brown; Robert P. Long

2013-01-01

Emerald ash borer (Agrilus planipennis) (EAB), an Asian woodboring beetle accidentally introduced in North America, has killed millions of ash (Fraxinus spp.) trees and is spreading rapidly. This study examined the effects of tree- and site-level factors on the mortality of ash trees in stands infested by EAB in OH, USA. Our data...

Response of black ash wetland gaseous soil carbon fluxes to a simulated emerald ash borer infestation

Treesearch

Matthew Van Grinsven; Joseph Shannon; Nicholas Bolton; Joshua Davis; Nam Noh; Joseph Wagenbrenner; Randall Kolka; Thomas Pypker

2018-01-01

The rapid and extensive expansion of emerald ash borer (EAB) in North America since 2002 may eliminate most existing ash stands, likely affecting critical ecosystem services associated with water and carbon cycling. To our knowledge, no studies have evaluated the coupled response of black ash (Fraxinus nigra Marsh.) wetland water tables, soil...

10 Risk to Ash from Emerald Ash Borer: Can Biological Control Prevent the Loss of Ash Stands

USDA-ARS?s Scientific Manuscript database

Ash trees were once relatively free of serious, major diseases and insect pests in North America until the arrival of EAB, which was first detected in North America in Michigan in 2002. As of February 2014, EAB had been detected in 22 U.S. states and two Canadian provinces, killing millions of ash ...

Hypocotyl derived in vitro regeneration of pumpkin ash (Fraxinus profunda)

Treesearch

Micah E. Stevens; Paula M. Pijut

2012-01-01

Pumpkin ash (Fraxinus profunda (Bush) Bush) is at risk for extirpation by an exotic insect, the emerald ash borer (EAB). Pumpkin ash is limited to wetland areas of the Eastern United States, and has been listed as an endangered species because of EAB activity. Pumpkin ash provides many benefits to the ecosystem, and its wood is used in the...

High spatial resolution spectral unmixing for mapping ash species across a complex urban environment

Treesearch

Jennifer Pontius; Ryan P. Hanavan; Richard A. Hallett; Bruce D. Cook; Lawrence A. Corp

2017-01-01

Ash (Fraxinus L.) species are currently threatened by the emerald ash borer (EAB; Agrilus planipennis Fairmaire) across a growing area in the eastern US. Accurate mapping of ash species is required to monitor the host resource, predict EAB spread and better understand the short- and long-term effects of EAB on the ash resource...

Effects of cutting time, stump height, and herbicide application on ash (Fraxinus spp.) stump sprouting and colonization by emerald ash borer (Agrilus planipennis)

Treesearch

Toby R. Petrice; Robert A. Haack

2011-01-01

Efforts to eradicate or slow the spread of emerald ash borer (EAB) (Agrilus planipennis Fairmaire [Coleoptera: Buprestidae]) include cutting infested and nearby uninfested ash (Fraxinus spp.) trees. However, ash trees readily sprout after they have been cut, providing potential host material for EAB. In 2004-2005, we conducted...

Potential effects of foundation species loss on wetland communities: A case study of black ash wetlands threatened by emerald ash borer

Treesearch

Melissa B. Youngquist; Sue L. Eggert; Anthony W. D' Amato; Brian J. Palik; Robert A. Slesak

2017-01-01

The emerald ash borer (EAB; Agrilus planipennis) is an invasive beetle that causes almost complete mortality of ash trees (Fraxinus spp.) in North America and Europe. Northern temperate wetlands, where black ash (F. nigra) is a dominant and foundation species, will likely undergo dramatic shifts after EAB...

Ashes to ashes: Large Fraxinus germplasm collections and their fates

Treesearch

Kim C. Steiner; Paul. Lupo

2010-01-01

As the emerald ash borer (EAB) threatens the survival of our ash species, measures should be taken to preserve their genetic variability in the event that we discover a way to restore populations destroyed by the beetle. As it happens, large germplasm collections exist for our most important and widely distributed eastern species of the genus, white ash (...

Use of unwounded ash trees for the detection of emerald ash borer adults: EAB landing behavior

Treesearch

Jordan M. Marshall; Melissa J. Porter; Andrew J. Storer

2011-01-01

Incorporation of multiple trapping techniques and sites within a survey program is essential to adequately identify the range of emerald ash borer (EAB) (Agrilus planipennis Fairmaire) infestation. Within natural forests, EAB lands on stick band traps wrapped around girdled ash trees at a rate similar to that on unwounded ash trees. The objective of...

Growth and physiological response of lemongrass (Cymbopogon citratus (D.C.) Stapf.) under different levels of fly ash-amended soil.

PubMed

Panda, Debabrata; Panda, Dibyajyoti; Padhan, Bandana; Biswas, Meghali

2018-05-12

Revegetation with metal tolerant plants for management of fly ash deposits is an important environmental perspective nowadays. Growth performance, photosynthesis, and antioxidant defense of lemongrass (Cymbopogon citratus (D.C.) Stapf.) were evaluated under various combination of fly ash amended with garden soil in order to assess its fly ash tolerance potential. Under low level of fly ash (25%) amended soil, the plant growth parameters such as shoot, root, and total plant biomass as well as metal tolerance index were increased compared to the control plants grown on garden soil, followed by decline under higher concentration of fly ash (50%, 75% and 100%). In addition, leaf photosynthetic rate, stomatal conductance, and photosystem (PS) II activity were not significantly changed under low level of fly ash (25%) amended soil compared to the garden soil but these parameters were significantly decreased further with increase of fly ash concentrations. Furthermore, increase of activities of some antioxidant enzymes such as superoxide dismutase, ascorbate peroxidase, and guaiacol peroxidase over control were noticed in lemongrass under all fly ash treatments. Taken together, the study suggests that lemongrass can be used for phytoremediation of fly ash at 25% amended soil.

Interspecific comparison of constitutive ash phloem phenolic chemistry reveals compounds unique to manchurian ash, a species resistant to emerald ash borer.

PubMed

Whitehill, Justin G A; Opiyo, Stephen O; Koch, Jennifer L; Herms, Daniel A; Cipollini, Donald F; Bonello, Pierluigi

2012-05-01

The emerald ash borer (Agrilus planipennis, EAB) is an invasive wood-borer indigenous to Asia and is responsible for widespread ash (Fraxinus spp.) mortality in the U.S. and Canada. Resistance and susceptibility to EAB varies among Fraxinus spp., which is a result of their co-evolutionary history with the pest. We characterized constitutive phenolic profiles and lignin levels in the phloem of green, white, black, blue, European, and Manchurian ash. Phloem was sampled twice during the growing season, coinciding with phenology of early and late instar EAB. We identified 66 metabolites that displayed a pattern of variation, which corresponded strongly with phylogeny. Previously identified lignans and lignan derivatives were confirmed to be unique to Manchurian ash, and may contribute to its high level of resistance to EAB. Other compounds that had been considered unique to Manchurian ash, including hydroxycoumarins and the phenylethanoids calceolarioside A and B, were detected in closely related, but susceptible species, and thus are unlikely to contribute to EAB resistance of Manchurian ash. The distinct phenolic profile of blue ash may contribute to its relatively high resistance to EAB.

Validation of Volcanic Ash Forecasting Performed by the Washington Volcanic Ash Advisory Center

NASA Astrophysics Data System (ADS)

Salemi, A.; Hanna, J.

2009-12-01

In support of NOAA’s mission to protect life and property, the Satellite Analysis Branch (SAB) uses satellite imagery to monitor volcanic eruptions and track volcanic ash. The Washington Volcanic Ash Advisory Center (VAAC) was established in late 1997 through an agreement with the International Civil Aviation Organization (ICAO). A volcanic ash advisory (VAA) is issued every 6 hours while an eruption is occurring. Information about the current location and height of the volcanic ash as well as any pertinent meteorological information is contained within the VAA. In addition, when ash is detected in satellite imagery, 6-, 12- and 18-hour forecasts of ash height and location are provided. This information is garnered from many sources including Meteorological Watch Offices (MWOs), pilot reports (PIREPs), model forecast winds, radiosondes and volcano observatories. The Washington VAAC has performed a validation of their 6, 12 and 18 hour airborne volcanic ash forecasts issued since October, 2007. The volcanic ash forecasts are viewed dichotomously (yes/no) with the frequency of yes and no events placed into a contingency table. A large variety of categorical statistics useful in describing forecast performance are then computed from the resulting contingency table.

Higher Activities of Defense-Associated Enzymes may Contribute to Greater Resistance of Manchurian Ash to Emerald Ash Borer Than A closely Related and Susceptible Congener.

PubMed

Rigsby, Chad M; Herms, Daniel A; Bonello, Pierluigi; Cipollini, Don

2016-08-01

Emerald ash borer (EAB) is an invasive beetle native to Asia that infests and kills ash (Fraxinus spp.) in North America. Previous experiments indicated that larvae feeding on co-evolved, resistant Manchurian ash (F. mandshurica) have increased antioxidant and quinone-protective enzyme activities compared to larvae feeding on susceptible North American species. Here, we examined mechanisms of host-generated oxidative and quinone-based stress and other putative defenses in Manchurian ash and the closely related and chemically similar, but susceptible, black ash (F. nigra), with and without exogenous application of methyl jasmonate (MeJA) to induce resistance mechanisms. Peroxidase activities were 4.6-13.3 times higher in Manchurian than black ash, although both species appeared to express the same three peroxidase isozymes. Additionally, peroxidase-mediated protein cross-linking activity was stronger in Manchurian ash. Polyphenol oxidase, β-glucosidase, chitinase, and lipoxygenase activities also were greater in Manchurian ash, but only lipoxygenase activity increased with MeJA application. Phloem H 2 O 2 levels were similar and were increased by MeJA application in both species. Lastly, trypsin inhibitor activity was detected in methanol and water extracts that were not allowed to oxidize, indicating the presence of phenolic-based trypsin inhibitors. However, no proteinaceous trypsin inhibitor activity was detected in either species. In response to MeJA application, Manchurian ash had higher trypsin inhibitor activity than black ash using the unoxidized water extracts, but no treatment effects were detected using methanol extracts. Based on these results we hypothesize that peroxidases, lignin polymerization, and quinone generation contribute to the greater resistance to EAB displayed by Manchurian ash.

Variation in the Volatile Profiles of Black and Manchurian Ash in Relation to Emerald Ash Borer Oviposition Preferences.

PubMed

Rigsby, Chad M; McCartney, Nathaniel B; Herms, Daniel A; Tumlinson, James H; Cipollini, Don

2017-08-01

Emerald ash borer (EAB; Agrilus planipennis) is a devastating pest of ash (Fraxinus spp.) in its invaded range in North America. Its coevolved Asian hosts are more resistant and less preferred for oviposition than susceptible North American species. We compared EAB oviposition preferences and bark and canopy volatile organic compound (VOC) emissions of resistant Manchurian ash and susceptible black ash, and examined relationships between VOC profiles and oviposition. In the field, black ash was highly preferred for oviposition while no eggs were laid on Manchurian ash, and we found clear differences in the VOC profiles of Manchurian and black ash. We detected 78 compounds emitted from these species, including 16 compounds that elicited EAB antennal activity in prior studies. Four compounds were unique to black and 11 to Manchurian ash. Emission rates of 14 canopy and 19 bark volatiles varied among the two species, including four previously reported as antennally active. Specifically, 7-epi-sesquithujene (bark) emissions were greater from black ash, while β-caryophyllene (canopy), linalool (bark), and α-cubebene (bark) were emitted at higher rates by Manchurian ash. No relationships were found between the emission rate of any single compound or group of compounds (e.g. monoterpenes) suggesting that preference may be based on complex profile combinations. This is the first study to directly compare VOCs of black and Manchurian ash as well as the first to examine bark- and canopy-specific VOCs. The unique bark and canopy VOC profiles of these two species implicates potentially important variation in VOCs between a closely related resistant and susceptible species that provides a foundation for future studies of host preferences of EAB.

Failure to phytosanitize ash firewood infested with emerald ash borer in a small dry kiln using ISPM-15 standards.

PubMed

Goebel, P Charles; Bumgardner, Matthew S; Herms, Daniel A; Sabula, Andrew

2010-06-01

Although current USDA-APHIS standards suggest that a core temperature of 71.1 degrees C (160 degrees F) for 75 min is needed to adequately sanitize emerald ash borer, Agrilus planipennis Fairmaire-infested firewood, it is unclear whether more moderate (and economical) treatment regimes will adequately eradicate emerald ash borer larvae and prepupae from ash firewood. We constructed a small dry kiln in an effort to emulate the type of technology a small- to medium-sized firewood producer might use to examine whether treatments with lower temperature and time regimes successfully eliminate emerald ash borer from both spilt and roundwood firewood. Using white ash (Fraxinus americana L.) firewood collected from a stand with a heavy infestation of emerald ash borer in Delaware, OH, we treated the firewood using the following temperature and time regime: 46 degrees C (114.8 degrees F) for 30 min, 46 degrees C (114.8 degrees F) for 60 min, 56 degrees C (132.8 degrees F) for 30 min, and 56 degrees C (132.8 degrees F) for 60 min. Temperatures were recorded for the outer 2.54-cm (1-in.) of firewood. After treatment, all firewood was placed under mesh netting and emerald ash borer were allowed to develop and emerge under natural conditions. No treatments seemed to be successful at eliminating emerald ash borer larvae and perpupae as all treatments (including two nontreated controls) experienced some emerald ash borer emergence. However, the 56 degrees C (132.8 degrees F) treatments did result in considerably less emerald ash borer emergence than the 46 degrees C (114.8 degrees F) treatments. Further investigation is needed to determine whether longer exposure to the higher temperature (56 degrees C) will successfully sanitize emerald ash borer-infested firewood.

Spreading dynamic of viscous volcanic ash in stimulated jet engine conditions

NASA Astrophysics Data System (ADS)

song, wenjia; Lavallée, Yan; Hess, Kai-Uwe; Kueppers, Ulrich; Cimarelli, Corrado

2016-04-01

The ingestion of volcanic ash is widely recognised as a potentially fatal hazard for aircraft operation. The volcanic ash deposition process in a jet turbine is potentially complex. Volcanic ash in the air stream enters the inner liners of the combustors and partially or completely melts under the flames up to 2000 °C, at which point part of the ash deposits in the combustor fuel nozzle. Molten volcanic particles within high energy airflow escape the combustor to enter the turbine and impact the stationary (e.g., inlet nozzle guide vanes) and rotating airfoils (e.g., first stage high-pressure turbine blades) at high speed (up to Mach 1.25) in different directions, with the result that ash may stick, flow and remain liquid or solidify. Thus, the wetting behaviour of molten volcanic ash particle is fundamental to investigate impingement phenomena of ash droplet on the surface of real jet engine operation. The topic of wetting has received tremendous interest from both fundamental and applied points of view. However, due to the interdisciplinary gap between jet engine engineering and geology science, explicit investigation of wetting behaviour of volcanic ash at high temperature is in its infancy. We have taken a big step towards meeting this challenge. Here, we experimentally and theoretically investigate the wetting behaviour of viscous volcanic ash over a wide temperature range from 1100 to 1550 °C using an improved sessile-drop method. The results of our experiment demonstrate that temperature and viscosity play a critical role in determining the wetting possibility and governing the spreading kinetics of volcanic ash at high temperatures. Our systemic analysis of spreading of molten volcanic ash systems allows us to report on the fundamental differences between the mechanisms controlling spreading of organic liquids at room temperature and molten volcanic ash droplets.

Effects of chemical composition of fly ash on efficiency of metal separation in ash-melting of municipal solid waste

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

Okada, Takashi, E-mail: t-okada@u-fukui.ac.jp; Tomikawa, Hiroki

2013-03-15

Highlights: ► Separation of Pb and Zn from Fe and Cu in ash-melting of municipal solid waste. ► Molar ratio of Cl to Na and K in fly ash affected the metal-separation efficiency. ► The low molar ratio and a non-oxidative atmosphere were better for the separation. - Abstract: In the process of metal separation by ash-melting, Fe and Cu in the incineration residue remain in the melting furnace as molten metal, whereas Pb and Zn in the residue are volatilized. This study investigated the effects of the chemical composition of incineration fly ash on the metal-separation efficiency of themore » ash-melting process. Incineration fly ash with different chemical compositions was melted with bottom ash in a lab-scale reactor, and the efficiency with which Pb and Zn were volatilized preventing the volatilization of Fe and Cu was evaluated. In addition, the behavior of these metals was simulated by thermodynamic equilibrium calculations. Depending on the exhaust gas treatment system used in the incinerator, the relationships among Na, K, and Cl concentrations in the incineration fly ash differed, which affected the efficiency of the metal separation. The amounts of Fe and Cu volatilized decreased by the decrease in the molar ratio of Cl to Na and K in the ash, promoting metal separation. The thermodynamic simulation predicted that the chlorination volatilization of Fe and Cu was prevented by the decrease in the molar ratio, as mentioned before. By melting incineration fly ash with the low molar ratio in a non-oxidative atmosphere, most of the Pb and Zn in the ash were volatilized leaving behind Fe and Cu.« less

Thermochemical formation of polychlorinated dibenzo-p-dioxins and dibenzofurans on the fly ash matrix from metal smelting sources.

PubMed

Wu, Xiaolin; Zheng, Minghui; Zhao, Yuyang; Yang, Hongbo; Yang, Lili; Jin, Rong; Xu, Yang; Xiao, Ke; Liu, Wenbin; Liu, Guorui

2018-01-01

Metal smelting processes are important sources of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). The present work aims to clarify the formation characteristics of PCDD/Fs by heterogeneous mechanisms on fly ash from typical multiple secondary aluminum (SAl), secondary lead (SPb) smelting, and iron ore sintering (SNT) sources in China. The formation characteristics of PCDD/Fs on fly ash were studied in the temperature range 250-450 °C for 10-150 min. Substantial thermochemical formation of PCDD/Fs on SAl and SNT ash was observed. The maximum increase of PCDD/F concentrations under 350 °C for 30 min was 604 times greater than the initial concentration in SAl ash. The concentration of PCDD/Fs was 77 times greater than that of SNT fly ash under 350 °C for 30 min. However, the maximum increase of PCDD/F concentrations was less than 8 times that in raw SPb ash under 350 °C. Contents of total organic carbon (TOC), Cu, Al, Zn and Cl, which are widely recognized as important elements for promoting PCDD/F formation, were obviously higher in SAl and SNT ash than in SPb ash. This may explain the greater observed formation times of PCDD/Fs on SAl and SNT ash than that on SPb ash. It was found that several congeners tended to form at higher temperatures than those for SAl ash. Activation energy calculation according to the Arrhenius equations could explain the dominant formation of those congeners at much higher temperatures on SAl ash. Copyright © 2017 Elsevier Ltd. All rights reserved.

Probabilistic detection of volcanic ash using a Bayesian approach.

PubMed

Mackie, Shona; Watson, Matthew

2014-03-16

Airborne volcanic ash can pose a hazard to aviation, agriculture, and both human and animal health. It is therefore important that ash clouds are monitored both day and night, even when they travel far from their source. Infrared satellite data provide perhaps the only means of doing this, and since the hugely expensive ash crisis that followed the 2010 Eyjafjalljökull eruption, much research has been carried out into techniques for discriminating ash in such data and for deriving key properties. Such techniques are generally specific to data from particular sensors, and most approaches result in a binary classification of pixels into "ash" and "ash free" classes with no indication of the classification certainty for individual pixels. Furthermore, almost all operational methods rely on expert-set thresholds to determine what constitutes "ash" and can therefore be criticized for being subjective and dependent on expertise that may not remain with an institution. Very few existing methods exploit available contemporaneous atmospheric data to inform the detection, despite the sensitivity of most techniques to atmospheric parameters. The Bayesian method proposed here does exploit such data and gives a probabilistic, physically based classification. We provide an example of the method's implementation for a scene containing both land and sea observations, and a large area of desert dust (often misidentified as ash by other methods). The technique has already been successfully applied to other detection problems in remote sensing, and this work shows that it will be a useful and effective tool for ash detection. Presentation of a probabilistic volcanic ash detection schemeMethod for calculation of probability density function for ash observationsDemonstration of a remote sensing technique for monitoring volcanic ash hazards.

Improved prediction and tracking of volcanic ash clouds

USGS Publications Warehouse

Mastin, Larry G.; Webley, Peter

2009-01-01

During the past 30??years, more than 100 airplanes have inadvertently flown through clouds of volcanic ash from erupting volcanoes. Such encounters have caused millions of dollars in damage to the aircraft and have endangered the lives of tens of thousands of passengers. In a few severe cases, total engine failure resulted when ash was ingested into turbines and coating turbine blades. These incidents have prompted the establishment of cooperative efforts by the International Civil Aviation Organization and the volcanological community to provide rapid notification of eruptive activity, and to monitor and forecast the trajectories of ash clouds so that they can be avoided by air traffic. Ash-cloud properties such as plume height, ash concentration, and three-dimensional ash distribution have been monitored through non-conventional remote sensing techniques that are under active development. Forecasting the trajectories of ash clouds has required the development of volcanic ash transport and dispersion models that can calculate the path of an ash cloud over the scale of a continent or a hemisphere. Volcanological inputs to these models, such as plume height, mass eruption rate, eruption duration, ash distribution with altitude, and grain-size distribution, must be assigned in real time during an event, often with limited observations. Databases and protocols are currently being developed that allow for rapid assignment of such source parameters. In this paper, we summarize how an interdisciplinary working group on eruption source parameters has been instigating research to improve upon the current understanding of volcanic ash cloud characterization and predictions. Improved predictions of ash cloud movement and air fall will aid in making better hazard assessments for aviation and for public health and air quality. ?? 2008 Elsevier B.V.

40 CFR 240.211-3 - Recommended procedures: Operations.

Code of Federal Regulations, 2011 CFR

2011-07-01

... every 60 minutes and as changes are made. (5) Weights of bottom ash, grate siftings, and fly ash.... (10) Gross calorific value of daily representative samples of bottom ash, grate siftings, and fly ash...

Volcanic ash impacts on critical infrastructure

NASA Astrophysics Data System (ADS)

Wilson, Thomas M.; Stewart, Carol; Sword-Daniels, Victoria; Leonard, Graham S.; Johnston, David M.; Cole, Jim W.; Wardman, Johnny; Wilson, Grant; Barnard, Scott T.

2012-01-01

Volcanic eruptions can produce a wide range of hazards. Although phenomena such as pyroclastic flows and surges, sector collapses, lahars and ballistic blocks are the most destructive and dangerous, volcanic ash is by far the most widely distributed eruption product. Although ash falls rarely endanger human life directly, threats to public health and disruption to critical infrastructure services, aviation and primary production can lead to significant societal impacts. Even relatively small eruptions can cause widespread disruption, damage and economic loss. Volcanic eruptions are, in general, infrequent and somewhat exotic occurrences, and consequently in many parts of the world, the management of critical infrastructure during volcanic crises can be improved with greater knowledge of the likely impacts. This article presents an overview of volcanic ash impacts on critical infrastructure, other than aviation and fuel supply, illustrated by findings from impact assessment reconnaissance trips carried out to a wide range of locations worldwide by our international research group and local collaborators. ‘Critical infrastructure’ includes those assets, frequently taken for granted, which are essential for the functioning of a society and economy. Electricity networks are very vulnerable to disruption from volcanic ash falls. This is particularly the case when fine ash is erupted because it has a greater tendency to adhere to line and substation insulators, where it can cause flashover (unintended electrical discharge) which can in turn cause widespread and disruptive outages. Weather conditions are a major determinant of flashover risk. Dry ash is not conductive, and heavy rain will wash ash from insulators, but light rain/mist will mobilise readily-soluble salts on the surface of the ash grains and lower the ash layer’s resistivity. Wet ash is also heavier than dry ash, increasing the risk of line breakage or tower/pole collapse. Particular issues for water supply managers include: monitoring turbidity levels in raw water intakes, and if necessary increasing chlorination to compensate for higher turbidity; managing water demand; and communicating monitoring results with the public to allay fears of contamination. Ash can cause major damage to wastewater disposal systems. Ash deposited onto impervious surfaces such as roads and car parks is very easily washed into storm drains, where it can form intractable masses and lead to long-term flooding problems. It can also enter wastewater treatment plants (WWTPs), both through sewer lines and by direct fallout. Damage to modern WWTPs can run into millions of dollars. Ash falls reduce visibility creating hazards for ground transportation. Dry ash is also readily remobilised by vehicle traffic and wind, and dry and wet ash deposits will reduce traction on paved surfaces, including airport runways. Ash cleanup from road and airports is commonly necessary, but the large volumes make it logistically challenging. Vehicles are vulnerable to ash; it will clog filters and brake systems and abrade moving parts within engines. Lastly, modern telecommunications networks appear to be relatively resilient to volcanic ash fall. Signal attenuation and interference during ash falls has not been reported in eruptions over the past 20 years, with the exception of interference from ash plume-generated lightning. However, some telecommunications equipment is vulnerable to airborne ash, in particular heating, ventilation and air-conditioning (HVAC) systems which may become blocked from ash ingestion leading to overheating. This summary of volcanic ash impacts on critical infrastructure provides insight into the relative vulnerability of infrastructure under a range of different ashfall scenarios. Identifying and quantifying these impacts is an essential step in building resilience within these critical systems. We have attempted to consider interdependencies between sectors in a holistic way using systems thinking. As modern society becomes increasingly complex and interdependent this approach is likely to become increasingly necessary.

The Best Estimated Trajectory Analysis for Pad Abort One

NASA Technical Reports Server (NTRS)

Kutty, Prasad; Noonan, Meghan; Karlgaard, Christopher; Beck, Roger

2011-01-01

I. Best Estimated Trajectory (BET) objective: a) Produce reconstructed trajectory of the PA-1 flight to understand vehicle dynamics and aid other post flight analyses. b) Leverage all measurement sources taken of vehicle during flight to produce the most accurate estimate of vehicle trajectory. c) Generate trajectory reconstructions of the Crew Module (CM), Launch Abort System (LAS), and Forward Bay Cover (FBC). II. BET analysis was started immediately following the PA-1 mission and was completed in September, 2010 a) Quick look version of BET released 5/25/2010: initial repackaging of SIGI data. b) Preliminary version of BET released 7/6/2010: first blended solution using available sources of external measurements. c) Final version of BET released 9/1/2010: final blended solution using all available sources of data.

Trends in the Rare Earth Element Content of U.S.-Based Coal Combustion Fly Ashes.

PubMed

Taggart, Ross K; Hower, James C; Dwyer, Gary S; Hsu-Kim, Heileen

2016-06-07

Rare earth elements (REEs) are critical and strategic materials in the defense, energy, electronics, and automotive industries. The reclamation of REEs from coal combustion fly ash has been proposed as a way to supplement REE mining. However, the typical REE contents in coal fly ash, particularly in the United States, have not been comprehensively documented or compared among the major types of coal feedstocks that determine fly ash composition. The objective of this study was to characterize a broad selection of U.S. fly ashes of varied geological origin in order to rank their potential for REE recovery. The total and nitric acid-extractable REE content for more than 100 ash samples were correlated with characteristics such as the major element content and coal basin to elucidate trends in REE enrichment. Average total REE content (defined as the sum of the lanthanides, yttrium, and scandium) for ashes derived from Appalachian sources was 591 mg kg(-1) and significantly greater than in ashes from Illinois and Powder River basin coals (403 and 337 mg kg(-1), respectively). The fraction of critical REEs (Nd, Eu, Tb, Dy, Y, and Er) in the fly ashes was 34-38% of the total and considerably higher than in conventional ores (typically less than 15%). Powder River Basin ashes had the highest extractable REE content, with 70% of the total REE recovered by heated nitric acid digestion. This is likely due to the higher calcium content of Powder River Basin ashes, which enhances their solubility in nitric acid. Sc, Nd, and Dy were the major contributors to the total REE value in fly ash, based on their contents and recent market prices. Overall, this study shows that coal fly ash production could provide a substantial domestic supply of REEs, but the feasibility of recovery depends on the development of extraction technologies that could be tailored to the major mineral content and origins of the feed coal for the ash.

Volcanic Ash on Slopes of Karymsky

NASA Technical Reports Server (NTRS)

2007-01-01

A volcanic eruption can produce gases, lava, bombs of rock, volcanic ash, or any combination of these elements. Of the volcanic products that linger on the land, most of us think of hardened lava flows, but volcanic ash can also persist on the landscape. One example of that persistence appeared on Siberia's Kamchatka Peninsula in spring 2007. On March 25, 2007, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite captured this image of the area around the Karymsky Volcano. In this image, volcanic ash from earlier eruptions has settled onto the snowy landscape, leaving dark gray swaths. The ash stains are confined to the south of the volcano's summit, one large stain fanning out toward the southwest, and another toward the east. At first glance, the ash stain toward the east appears to form a semicircle north of the volcano and sweep back east. Only part of this dark shape, however, is actually volcanic ash. Near the coast, the darker color may result from thicker vegetation. Similar darker coloring appears to the south. Volcanic ash is not really ash at all, but tiny, jagged bits of rock and glass. These jagged particles pose serious health risks to humans and animals who might inhale them. Likewise, the ash poses hazards to animals eating plants that have been coated with ash. Because wind can carry volcanic ash thousands of kilometers, it poses a more far-reaching hazard than other volcanic ejecta. Substantial amounts of ash can even affect climate by blocking sunlight. Karymsky is a stratovolcano composed of alternating layers of solidified ash, hardened lava, and volcanic rocks. It is one of many active volcanoes on Russia's Kamchatka Peninsula, which is part of the 'Ring of Fire' around the Pacific Rim. NASA image created by Jesse Allen, using data provided courtesy of the NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team.

Mobility and toxicity of heavy metal(loid)s arising from contaminated wood ash application to a pasture grassland soil.

PubMed

Mollon, L C; Norton, G J; Trakal, L; Moreno-Jimenez, E; Elouali, F Z; Hough, R L; Beesley, L

2016-11-01

Heavy metal(loid) rich ash (≤10,000 mg kg -1 total As, Cr, Cu and Zn) originating from the combustion of contaminated wood was subjected to several experimental procedures involving its incorporation into an upland pasture soil. Ash was added to soil that had been prior amended with local cattle manure, replicating practices employed at the farm scale. Metal(loid) concentrations were measured in soil pore water and ryegrass grown on soil/manure plus ash mixtures (0.1-3.0% vol. ash) in a pot experiment; toxicity evaluation was performed on the same pore water samples by means of a bacterial luminescence biosensor assay. Thereafter a sequential extraction procedure was carried out on selected soil, manure and ash mixtures to elucidate the geochemical association of ash derived metal(loid)s with soil constituents. Predictive modelling was applied to selected data from the pot experiment to determine the risk of transfer of As to meat and milk products in cattle grazing pasture amended with ash. The inclusion of manure to soils receiving ash reduced phyto-toxicity and increased ryegrass biomass yields, compared to soil with ash, but without manure. Elevated As and Cu concentrations in pore water and ryegrass tissue resulting from ash additions were reduced furthest by the inclusion of manure due to an increase in their geochemical association with organic matter. Zinc was the only measured metal(loid) to remain uniformly soluble and bioavailable regardless of the addition of ash and manure. Risk modelling on pot experimental data highlighted that an ash addition of >1% (vol.) to this pasture soil could result in As concentrations in milk and meat products exceeding acceptable limits. The results of this study therefore suggest that even singular low doses of ash applied to soil increase the risk of leaching of metal(loid)s and intensify the risk of As transfer in the food chain. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effects of fire on ash thickness in a Lithuanian grassland and short-term spatio-temporal changes

NASA Astrophysics Data System (ADS)

Pereira, P.; Cerdà, A.; Úbeda, X.; Mataix-Solera, J.; Martin, D.; Jordán, A.; Burguet, M.

2012-12-01

Ash thickness is a key variable in the protection of soil against erosion agents after planned and unplanned fires. Thicker ash provides better protection against raindrop impact and reduces the runoff response by retaining water and promoting water infiltration although little is known about the distribution and the evolution of the ash layer after the fires. Ash thickness measurements were conducted along two transects (flat and sloping areas) following a a grid experimental design. Both transects extended from the burned area into an adjacent unburned area. We analysed ash thickness evolution according to time and fire severity. In order to interpolate data with accuracy and identify the techniques with the least bias, several interpolation methods were tested in the grid plot. Overall, the fire had a low severity. The fire significantly reduced the ground cover, especially on sloping areas owing to the higher fire severity and/or less biomass previous to the fire. Ash thickness depends on fire severity and is thin where fire severity was higher and thicker in lower fire severity sites. The ash thickness decreased with time after the fire. Between 4 and 16 days after the fire, ash was transported by wind. The major reduction took place between 16 and 34 days after the fire as a result of rainfall, and was more efficient where fire severity was higher. Between 34 and 45 days after the fire no significant differences in ash thickness were identified among ash colours and only traces of the ash layer remained. The omni-directional experimental variograms shown that variable structure did not change importantly with the time, however, the most accurate interpolation methods were different highlighting the slight different patterns of ash thickness distribution with the time. The ash spatial variability increased with the time, particularly on the slope, as a result of water erosion.

Leaching characteristics of ash from the May 18, 1980, eruption of Mount St. Helens Volcano, Washington

USGS Publications Warehouse

Smith, David Burl; Zielinski, Robert A.; Taylor, Howard E.

1982-01-01

Leaching of freshly erupted air-fall ash, unaffected by rain, from the May 18, 1.980,eruption of Mount St. Helens volcano, Washington, shows that Ca 2+, Na+, Mg+, SO4 2-, and Cl- are the predominant chemical species released on first exposure of the ash to water. Extremely high correlation of Ca with SO4 and Na with Cl in water leachates suggests the presence of CaSO4 and NaCl salts on the ash. The amount of water soluble material on ash increases with distance from source and with the weight fraction of small (less than 63 micrometers) ash particles of high-surface area. This suggests that surface reactions such as adsorption are responsible for concentrating the soluble material. CaSO4, NaCl, and other salts are probably formed as microscopic crystals in the high-temperature core of the eruption column and are then adsorbed by silicate ash particles. The environmentally important elements Zn, Cu, Cd, F, Pb, and Ba are released by a water leach in concentrations which could pose short-term hazards to some forms of aquatic life. However, calculated concentrations are based on a water-to-ash ratio of 4:1 or less, which is probably an underestimation of the regionally operative ratio. A subsequent leach of ash by warm alkaline solution shows dramatic increases in the amount of dissolved SiO2, U, and V, which are probably caused by increased dissolution of the glassy component of ash. Glass dissolution by alkaline ground water is a mechanism for providing these three elements to sedimentary traps where they may co-accumulate as uraniferous silica or U-V minerals. Leaching characteristics of ash from Mount St. Helens are comparable to characteristics of ash of similar composition from volcanoes in Guatemala. Ashes from each locality show similar ions predominating for a given leachate and similar fractions of a particular element in the ash removed on contact with the leach solution.

Retrieval of volcanic ash properties from the Infrared Atmospheric Sounding Interferometer (IASI)

NASA Astrophysics Data System (ADS)

Ventress, Lucy; Carboni, Elisa; Smith, Andrew; Grainger, Don; Dudhia, Anu; Hayer, Catherine

2014-05-01

The Infrared Atmospheric Sounding Interferometer (IASI), on board both the MetOp-A and MetOp-B platforms, is a Fourier transform spectrometer covering the mid-infrared (IR) from 645-2760cm-1 (3.62-15.5 μm) with a spectral resolution of 0.5cm-1 (apodised) and a pixel diameter at nadir of 12km. These characteristics allow global coverage to be achieved twice daily for each instrument and make IASI a very useful tool for the observation of larger aerosol particles (such as desert dust and volcanic ash) and the tracking of volcanic plumes. In recent years, following the eruption of Eyjafjallajökull, interest in the the ability to detect and characterise volcanic ash plumes has peaked due to the hazards to aviation. The thermal infrared spectra shows a rapid variation with wavelength due to absorption lines from atmospheric and volcanic gases as well as broad scale features principally due to particulate absorption. The ash signature depends upon both the composition and size distribution of ash particles as well as the altitude of the volcanic plume. To retrieve ash properties, IASI brightness temperature spectra are analysed using an optimal estimation retrieval scheme and a forward model based on RTTOV. Initially, IASI pixels are flagged for the presence of volcanic ash using a linear retrieval detection method based on departures from a background state. Given a positive ash signal, the RTTOV output for a clean atmosphere (containing atmospheric gases but no cloud or aerosol/ash) is combined with an ash/cloud layer using the same scheme as for the Oxford-RAL Retrieval of Aerosol and Cloud (ORAC) algorithm. The retrieved parameters are ash optical depth (at a reference wavelength of 550nm), ash effective radius, layer altitude and surface temperature. The potential for distinguishing between different ash types is explored and a sensitivity study of the retrieval algorithm is presented. Results are shown from studies of the evolution and composition of ash plumes for recent volcanic eruptions.

Aluminum-fly ash metal matrix composites for automotive parts. [Reports for April 1 to June 30, 1999, and July 1 to September 30, 1999

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

Weiss, David; Purgert, Robert; Rhudy, Richard

1999-10-15

Some highlights are: (1) During this quarter's field trials, sand mold castings of parts and permanent mold tensile testing bars, K mold bars, and ingots were made from aluminum alloy-fly ash melts. (2) Another objective was met, i.e., to use class ''F'' type precipitator fly ash consisting of particle sizes less than 100 microns. It was possible to pour the composite melt into the sand mold through a filter. (3) Trials were run to determine the required amount of the wetting agent, magnesium, to ensure appropriate mixing of the aluminum alloy and fly ash. The magnesium content required to mixmore » ''F'' fly ash was much lower compared to that required to mix hybrid ''C-F'' fly ash in similar melts. Fly ash particles of less than 100 microns were mixed in aluminum melt. Large scale field trials were undertaken at Eck Industries with the goal of standardizing procedures for producing aluminum-fly ash composite melts and to analyze the structure and properties of the resulting material. Limited testing of tensile properties has been done on pressure die cast parts, and attempts are underway to improve the distribution of fly ash in both sand cast and pressure die cast samples. Eck Industries performed radiographic, heat treatment, and tensile tests on permanent mold cast tensile test bars. After fly ash mixing experiments, the Lanxide high speed-high shear mixer (originally designed for mixing Al-SiC melts) was employed in an attempt to avoid fly ash agglomeration. It led to demixing (instead of deagglomerating) of some fly ash. However, the permanent mold tensile bars poured after high shear mixing displayed good distribution of fly ash in castings. A modified impeller design is being considered for high speed-high shear mixing of aluminum-fly ash melts.« less

Environmentally friendly use of non-coal ashes in Sweden.

PubMed

Ribbing, C

2007-01-01

The Swedish Thermal Engineering Research Institute (Värmeforsk) initiated an applied research program "Environmentally friendly use of non-coal ashes", in 2002. The program aims at increasing knowledge on the by-products of energy production and their application. The goal of formulating technical and environmental guidelines and assessments is a major point of the program, which is supported by about forty authorities and private organisations. The programme has been divided into four areas: recycling of ashes to forests, geotechnical applications, use in landfilling, and environmental aspects and chemistry. Among all results obtained, the following progress is shown: *Evidence for the positive effects of spreading ashes on forest growth. *A proposal for environmental guidelines on the utilisation of ashes in construction. *A handbook for using non-coal fly ashes in unpaved roads. *Technical and environmental assessments of MSWI bottom ashes in road construction. *Development of the use of ashes with municipal wastewater sludge as a cover for landfills and mine tailings. *Use of ashes from bio-fuels in concrete and replacement of cement in stoop mining. *A method to classify those by-products from combustion that have mirror entries in the EWC as a hazardous or non-hazardous compound. The Ash Programme has also made it possible to increase knowledge on ashes as valuable materials, on quality assurance and on markets for recovered materials.

Intra- and inter-unit variation in fly ash petrography and mercury adsorption: Examples from a western Kentucky power station

USGS Publications Warehouse

Hower, J.C.; Finkelman, R.B.; Rathbone, R.F.; Goodman, J.

2000-01-01

Fly ash was collected from eight mechanical and 10 baghouse hoppers at each of the twin 150-MW wall-fired units in a western Kentucky power station. The fuel burned at that time was a blend of many low-sulfur, high-volatile bituminous Central Appalachian coals. The baghouse ash showed less variation between units than the mechanical hoppers. The mechanical fly ash, coarser than the baghouse ash, showed significant differences in the amount of total carbon and in the ratio of isotropic coke to both total carbon and total coke - the latter excluding inertinite and other unburned, uncoked coal. There was no significant variation in proportions of inorganic fly ash constituents. The inter-unit differences in the amount and forms of mechanical fly ash carbon appear to be related to differences in pulverizer efficiency, leading to greater amounts of coarse coal, therefore unburned carbon, in one of the units. Mercury capture is a function of both the total carbon content and the gas temperature at the point of fly ash separation, mercury content increasing with an increase in carbon for a specific collection system. Mercury adsorption on fly ash carbon increases at lower flue-gas temperatures. Baghouse fly ash, collected at a lower temperature than the higher-carbon mechanically separated fly ash, contains a significantly greater amount of Hg.

A review on the effect of fly ash characteristics and their variations on the synthesis of fly ash based geopolymer

NASA Astrophysics Data System (ADS)

Wattimena, Oswyn K.; Antoni, Hardjito, Djwantoro

2017-09-01

There are more than four decades since the last 1970s where geopolymers concrete was first introduced and developed to use as a replacement to conventional concrete material which uses cement as a binder. And since the last two decades, geopolymers which utilized fly ash as aluminosilicate source material, i.e. fly ash based geopolymers, have been investigated. Many researchers present how to produce the best fly ash based geopolymer with a various source of constituent material as well as mixing formula to achieve exceptional concrete performance. Although there is a similar trend towards factors affecting the result of fly ash based geopolymer synthesis, there is still remain a wide range in mixture proportion. The considerable variation in fly ash characteristics as source material in the synthesis can very likely be one of the causes of this problem. This paper attempts to identify the effect of source material variation of geopolymer concrete, particularly which use fly ash as source material and focuses on the variation of its characteristics and the effects to properties of concrete. From the reviews it concluded that different sources (and even the same source, but different batch) of fly ash materials will give some different characteristics of the fly ash, where it would affect the synthesis process of the fly ash based geopolymer concretes.

Effects of water availability on emerald ash borer larval performance and phloem phenolics of Manchurian and black ash.

PubMed

Chakraborty, Sourav; Whitehill, Justin G A; Hill, Amy L; Opiyo, Stephen O; Cipollini, Don; Herms, Daniel A; Bonello, Pierluigi

2014-04-01

The invasive emerald ash borer (EAB) beetle is a significant threat to the survival of North American ash. In previous work, we identified putative biochemical and molecular markers of constitutive EAB resistance in Manchurian ash, an Asian species co-evolved with EAB. Here, we employed high-throughput high-performance liquid chromatography with photodiode array detection and mass spectrometry (HPLC-PDA-MS) to characterize the induced response of soluble phloem phenolics to EAB attack in resistant Manchurian and susceptible black ash under conditions of either normal or low water availability, and the effects of water availability on larval performance. Total larval mass per tree was lower in Manchurian than in black ash. Low water increased larval numbers and mean larval mass overall, but more so in Manchurian ash. Low water did not affect levels of phenolics in either host species, but six phenolics decreased in response to EAB. In both ashes, pinoresinol A was induced by EAB, especially in Manchurian ash. Pinoresinol A and pinoresinol B were negatively correlated with each other in both species. The higher accumulation of pinoresinol A in Manchurian ash after attack may help explain the resistance of this species to EAB, but none of the responses measured here could explain increased larval performance in trees subjected to low water availability. © 2013 John Wiley & Sons Ltd.

Thermal treatment and vitrification of boiler ash from a municipal solid waste incinerator.

PubMed

Yang, Y; Xiao, Y; Voncken, J H L; Wilson, N

2008-06-15

Boiler ash generated from municipal solid waste (MSW) incinerators is usually classified as hazardous materials and requires special disposal. In the present study, the boiler ash was characterized for the chemical compositions, morphology and microstructure. The thermal chemical behavior during ash heating was investigated with thermal balance. Vitrification of the ash was conducted at a temperature of 1400 degrees C in order to generate a stable silicate slag, and the formed slag was examined with chemical and mineralogical analyses. The effect of vitrification on the leaching characteristics of various elements in the ash was evaluated with acid leaching. The study shows that the boiler ash as a heterogeneous fine powder contains mainly silicate, carbonate, sulfates, chlorides, and residues of organic materials and heavy metal compounds. At elevated temperatures, the boiler ash goes through the initial moisture removal, volatilization, decomposition, sintering, melting, and slag formation. At 1400 degrees C a thin layer of salt melt and a homogeneous glassy slag was formed. The experimental results indicate that leaching values of the vitrified slag are significantly reduced compared to the original boiler ash, and the vitrification could be an interesting alternative for a safer disposal of the boiler ash. Ash compacting, e.g., pelletizing can reduce volatilization and weight loss by about 50%, and would be a good option for the feed preparation before vitrification.

The leaching characteristics of selenium from coal fly ashes

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

Wang, T.; Wang, J.; Burken, J.G.

2007-11-15

The leaching characteristics of selenium from several bituminous and subbituminous coal fly ashes under different pH conditions were investigated using batch methods. Results indicated that pH had a significant effect on selenium leaching from bituminous coal ash. The minimum selenium leaching occurred in the pH range between 3 and 4, while the maximum selenium leaching occurred at pH 12. The release of selenium from subbituminous coal ashes was very low for the entire experimental pH range, possibly due to the high content of calcium which can form hydration or precipitation products as a sink for selenium. The adsorption results formore » different selenium species indicated that Se(VI) was hardly adsorbable on either bituminous coal ashes or subbitumminous coal ashes at any pH. However, Se(I) was highly adsorbed by bituminous coal ashes under acidic pH conditions and was mostly removed by subbitumminous coal ashes across the entire pH range. This result suggests that the majority of selenium released from the tested fly ashes was Se(IV). A speciation-based model was developed to simulate the adsorption of Se(IV) on bituminous coal fly ash, and the pH-independent adsorption constants of HSeO{sup 3-} and SeO{sub 3}{sup 2-} were determined. The modeling approach is useful for understanding and predicting the release process of selenium from fly ash.« less

High-volume fly ash concrete.

DOT National Transportation Integrated Search

2013-06-01

The objective of the proposed study is to design, test, and evaluate high-volume fly ash concrete mixtures. Traditional specifications : limit the amount of fly ash to 40% or less cement replacement. This program attempts to increase the ash content ...

Method for increasing the rate of compressive strength gain in hardenable mixtures containing fly ash

DOEpatents

Liskowitz, J.W.; Wecharatana, M.; Jaturapitakkul, C.; Cerkanowicz, A.E.

1997-10-28

The present invention relates to concrete, mortar and other hardenable mixtures comprising cement and fly ash for use in construction. The invention provides a method for increasing the rate of strength gain of a hardenable mixture containing fly ash by exposing the fly ash to an aqueous slurry of calcium oxide (lime) prior to its incorporation into the hardenable mixture. The invention further relates to such hardenable mixtures, e.g., concrete and mortar, that contain fly ash pre-reacted with calcium oxide. In particular, the fly ash is added to a slurry of calcium oxide in water, prior to incorporating the fly ash in a hardenable mixture. The hardenable mixture may be concrete or mortar. In a specific embodiment, mortar containing fly ash treated by exposure to an aqueous lime slurry are prepared and tested for compressive strength at early time points. 2 figs.

Method for increasing the rate of compressive strength gain in hardenable mixtures containing fly ash

DOEpatents

Liskowitz, John W.; Wecharatana, Methi; Jaturapitakkul, Chai; Cerkanowicz, deceased, Anthony E.

1997-01-01

The present invention relates to concrete, mortar and other hardenable mixtures comprising cement and fly ash for use in construction. The invention provides a method for increasing the rate of strength gain of a hardenable mixture containing fly ash by exposing the fly ash to an aqueous slurry of calcium oxide (lime) prior to its incorporation into the hardenable mixture. The invention further relates to such hardenable mixtures, e.g., concrete and mortar, that contain fly ash pre-reacted with calcium oxide. In particular, the fly ash is added to a slurry of calcium oxide in water, prior to incorporating the fly ash in a hardenable mixture. The hardenable mixture may be concrete or mortar. In a specific embodiment, mortar containing fly ash treated by exposure to an aqueous lime slurry are prepared and tested for compressive strength at early time points.

Possibilities of municipal solid waste incinerator fly ash utilisation.

PubMed

Hartmann, Silvie; Koval, Lukáš; Škrobánková, Hana; Matýsek, Dalibor; Winter, Franz; Purgar, Amon

2015-08-01

Properties of the waste treatment residual fly ash generated from municipal solid waste incinerator fly ash were investigated in this study. Six different mortar blends with the addition of the municipal solid waste incinerator fly ash were evaluated. The Portland cement replacement levels of the municipal solid waste incinerator fly ash used were 25%, 30% and 50%. Both, raw and washed municipal solid waste incinerator fly ash samples were examined. According to the mineralogical composition measurements, a 22.6% increase in the pozzolanic/hydraulic properties was observed for the washed municipal solid waste incinerator fly ash sample. The maximum replacement level of 25% for the washed municipal solid waste incinerator fly ash in mortar blends was established in order to preserve the compressive strength properties. Moreover, the leaching characteristics of the crushed mortar blend was analysed in order to examine the immobilisation of its hazardous contents. © The Author(s) 2015.

Regeneratively cooled coal combustor/gasifier with integral dry ash removal

DOEpatents

Beaufrere, A.H.

1982-04-30

A coal combustor/gasifier is disclosed which produces a low or medium combustion gas fired furnances or boilers. Two concentric shells define a combustion air flows to provide regenerative cooling of the inner shell for dry ash operation. A fuel flow and a combustion air flow having opposed swirls are mixed and burned in a mixing-combustion portion of the combustion volume and the ash laden combustion products flow with a residual swirl into an ash separation region. The ash is cooled below the fusion temperature and is moved to the wall by centrifugal force where it is entrained in the cool wall boundary layer. The boundary layer is stabilized against ash re-entrainment as it is moved to an ash removal annulus by a flow of air from the plenum through slots in the inner shell, and by suction on an ash removal skimmer slot.

The study of the burning possibilities of solid combustibles in the determined conditions for complete usage of caloric [energy] and ashes resulted

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

Voina, N.I.; Barca, F.; Mogos, D.

1995-12-31

In modern combustors, 95--98% of the organic mass of a solid combustible is converted into caloric energy; 2--4% remain in the fly ash captured in electrofilters and hydraulically removed in most cases. The 2--4% unburned materials in fly ash, together with the water from being hydraulically transported, make it difficult for the use of the fly ash for metal extraction or as a binder in the materials industry. This work presents the research results of a study in which the burning process was modified to result in fly ash without carbon content and fly ash removal by dry capture. Laboratorymore » fluidized-bed combustion of lignite with and without addition of limestone for sulfur capture was used to generate ashes for further study. The ashes were studied for their use as binders and as a cement substitute.« less

Geochemical and analytical implications of extensive sulfur retention in ash from Indonesian peats

USGS Publications Warehouse

Kane, Jean S.; Neuzil, Sandra G.

1993-01-01

Sulfur is an analyte of considerable importance to the complete major element analysis of ash from low-sulfur, low-ash Indonesian peats. Most analytical schemes for major element peat- and coal-ash analyses, including the inductively coupled plasma atomic emission spectrometry method used in this work, do not permit measurement of sulfur in the ash. As a result, oxide totals cannot be used as a check on accuracy of analysis. Alternative quality control checks verify the accuracy of the cation analyses. Cation and sulfur correlations with percent ash yield suggest that silicon and titanium, and to a lesser extent, aluminum, generally originate as minerals, whereas magnesium and sulfur generally originate from organic matter. Cation correlations with oxide totals indicate that, for these Indonesian peats, magnesium dominates sulfur fixation during ashing because it is considerably more abundant in the ash than calcium, the next most important cation in sulfur fixation.

The Wireless Sensor Network (WSN) Based Coal Ash Impoundments Safety Monitoring System

NASA Astrophysics Data System (ADS)

Sun, E. J.; Nieto, A.; Zhang, X. K.

2017-01-01

Coal ash impoundments are inevitable production of the coal-fired power plants. All coal ash impoundments in North Carolina USA that tested for groundwater contamination are leaking toxic heavy metals and other pollutants. Coal ash impoundments are toxic sources of dangerous pollutants that pose a danger to human and environmental health if the toxins spread to adjacent surface waters and drinking water wells. Coal ash impoundments failures accidents resulted in serious water contamination along with toxic heavy metals. To improve the design and stability of coal ash impoundments, the Development of a Coal Ash Impoundment Safety Monitoring System (CAISM) was proposed based on the implementation of a wireless sensor network (WSN) with the ability to monitor the stability of coal ash impoundments, water level, and saturation levels on-demand and remotely. The monitoring system based on a robust Ad-hoc network could be adapted to different safety conditions.

Volcanic ash melting under conditions relevant to ash turbine interactions.

PubMed

Song, Wenjia; Lavallée, Yan; Hess, Kai-Uwe; Kueppers, Ulrich; Cimarelli, Corrado; Dingwell, Donald B

2016-03-02

The ingestion of volcanic ash by jet engines is widely recognized as a potentially fatal hazard for aircraft operation. The high temperatures (1,200-2,000 °C) typical of jet engines exacerbate the impact of ash by provoking its melting and sticking to turbine parts. Estimation of this potential hazard is complicated by the fact that chemical composition, which affects the temperature at which volcanic ash becomes liquid, can vary widely amongst volcanoes. Here, based on experiments, we parameterize ash behaviour and develop a model to predict melting and sticking conditions for its global compositional range. The results of our experiments confirm that the common use of sand or dust proxy is wholly inadequate for the prediction of the behaviour of volcanic ash, leading to overestimates of sticking temperature and thus severe underestimates of the thermal hazard. Our model can be used to assess the deposition probability of volcanic ash in jet engines.

Construction of a Dry Ash Dam with Soilbags and Slope Stability Analysis

NASA Astrophysics Data System (ADS)

Li, Hui; Song, Yingjun; Gao, Jiaorong; Li, Longhua; Zhou, Yuqi; Qi, Hui

2017-12-01

In thermal power plants, it is necessary to build ash dams to store fly ash, which is the by-product after the combustion of coals. To solve the problem of lacking rockfill materials in Africa, A new technology of constructing ash dams using solibags filled with local sands is proposed and the method of analyzing its slope stability is suggested. The design of the ash dam using soilbags in Lamb Thermal Power Plant of Kenya is introduced in detail. The slope stability of the soilbags-constructed ash dam was analyzed by adopting the suggested method. The results show that the soilbags filled with ash or sands have high compressive strength, and the primary dam constructed with soilbags can effectively retain the backfill ash and the stacking dam reinforced with soilbags can stand stable even with the slope of 1:1.5.

Volcanic Ash fall Impact on Vegetation, Colima 2005

NASA Astrophysics Data System (ADS)

Garcia, M. G.; Martin, A.; Fonseca, R.; Nieto, A.; Radillo, R.; Armienta, M.

2007-05-01

An ash sampling network was established arround Colima Volcano in 2005. Ash fall was sampled on the North, Northeast, East, Southeast, South, Southwest and West of the volcano. Samples were analyzed for ash components, geochemistry and leachates. Ash fall ocurred on April (12), May (10, 23), June (2, 6, 9, 10, 12, 14), July (27), September (27), October (23) and November (24). Most of the ash is made of andesitic dome-lithics but shows diferences in crystal, juvenile material and lithic content. In May, some samples contained grey and dark pumice (scoria). Texture varies from phi >4 to phi 0. Leachate concentration were low: SO4 (7.33-54.19) Cl- (2.29-4.97) and F- (0.16-0.37). During 2005, Colima Volcano's ash fall rotted some of the guava and peach fruits and had a drying effect on spearment and epazote plants. Even these small ash amounts could have hindered sugar cane and agave growth.

Water table response to harvesting and simulated emerald ash borer mortality in black ash wetlands in Minnesota, USA

Treesearch

Robert A. Slesak; Christian F. Lenhart; Kenneth N. Brooks; Anthony W. D' Amato; Brian J. Palik

2014-01-01

Black ash wetlands are seriously threatened because of the invasive emerald ash borer (EAB). Wetland hydrology is likely to be modified following ash mortality, but the magnitude of hydrological impact following loss via EAB and alternative mitigation harvests is not clear. Our objective was to assess the water table response to simulated EAB and harvesting to...

Patterns of Coarse Woody Debris in Hardwood Forests across a Chronosequence of Ash Mortality Due to the Emerald Ash Borer (Agrilus planipennis)

Treesearch

Matt Higham; Brian M. Hoven; David L. Gorchov; Kathleen S. Knight

2017-01-01

The invasive emerald ash borer (Agrilus planipennis) (EAB) is causing widespread ash (Fraxinus spp.) mortality in 25 U.S. states and two Canadian provinces. We investigated the impact of EAB on coarse woody debris (CWD) volume across 24 sites in western and central Ohio, USA, representing a chronosequence of ash mortality,...

Emerald Ash Borer: Invasion of the Urban Forest and the Threat to North America's Ash Resource

Treesearch

Therese M. Poland; Deborah G. McCullough

2006-01-01

The emerald ash borer (EAB), a phloem-feeding beetle native to Asia, was discovered killing ash trees in southeastern Michigan and Windsor, Ontario, in 2002. Like several other invasive forest pests, the EAB likely was introduced and became established in a highly urbanized setting, facilitated by international trade and abundant hosts. Up to 15 million ash trees in...

Update on exotic ash collection for hybrid breeding and survey for EAB-resistance in native North American species

Treesearch

Mary E. Mason; Daniel A. Herms; David W. Carey; Kathleen S. Knight; Nurul I. Faridi; Jennifer. Koch

2011-01-01

Contrary to the high levels of devastation observed on North American ash species infested with emerald ash borer (EAB) (Agrilus planipennis Fairmaire), reports from Asia indicate that EAB-induced destruction of Asian ash species is limited to stressed trees. This indicates that Asian ash species have co-evolved resistance, or at least a high degree...

Ash cap influences on site productivity and fertilizer response in forests of the Inland Northwest

Treesearch

Mariann T. Garrison-Johnston; Peter G. Mika; Dan L. Miller; Phil Cannon; Leonard R. Johnson

2007-01-01

Data from 139 research sites throughout the Inland Northwest were analyzed for effects of ash cap on site productivity, nutrient availability and fertilization response. Stand productivity and nitrogen (N) fertilizer response were greater on sites with ash cap than on sites without. Where ash was present, depth of ash had no effect on site productivity or N fertilizer...

Seasonal Variations in Ash Content of Some Michigan Forest Floor Fuels

Treesearch

Robert M. Loomis

1982-01-01

Samples from the forest floor litter layer were collected seasonally from under medium to fully stocked larger sapling to sawtimber stands in Lower Michigan to study seasonal ash content changes. The total ash and silica-free ash content of tree foliage in the upper part of the litter layer differed little from season to season. Differences in ash content due to...