Stability of the cytoskeleton of matured buffalo oocytes pretreated with cytochalasin B prior to vitrification.

Science.gov (United States)

Wang, C L; Xu, H Y; Xie, L; Lu, Y Q; Yang, X G; Lu, S S; Lu, K H

2016-06-01

Stabilizing the cytoskeleton system during vitrification can improve the post-thaw survival and development of vitrified oocytes. The cytoskeleton stabilizer cytochalasin B (CB) has been used in cryopreservation to improve the developmental competence of vitrified oocytes. To assess the effect of pretreating matured buffalo oocytes with CB before vitrification, we applied 0, 4, 8, or 12 μg/mL CB for 30 min. The optimum concentration of CB treatment (8 μg/mL for 30 min) was then used to evaluate the distribution of microtubules and microfilaments, the expression of the cytoskeleton proteins actin and tubulin, and the developmental potential of matured oocytes that were vitrified-warmed by the Cryotop method. Western blotting demonstrated that vitrification significantly decreased tubulin expression, but that the decrease was attenuated for oocytes pretreated with 8 μg/mL CB before vitrification. After warming and intracytoplasmic sperm injection, oocytes that were pretreated with 8 μg/mL CB before vitrification yielded significantly higher 8-cell and blastocyst rates than those that were vitrified without CB pretreatment. The values for the vitrified groups in all experiments were significantly lower (P < 0.01) than those of the control groups. In conclusion, pretreatment with 8 μg/mL CB for 30 min significantly improves the cytoskeletal structure, expression of tubulin, and development capacity of vitrified matured buffalo oocytes. Copyright © 2016 Elsevier Inc. All rights reserved.

Effect of Pre-treatment method on the Hydrolysis of Corn cob and Sawdust

Directory of Open Access Journals (Sweden)

Olawole Ogirima Olanipekun

2016-12-01

Full Text Available Efficient pre-treatment has been found to be crucial step before enzymatic hydrolysis of cellulose into fuels or chemicals. As a result various pretreatment methods have been developed to facilitate these bio-conversion processes, and this research focuses on the effect of two pretreatment methods such as liquid hot water and sulphuric acid pre-treatment to remove some of the components like lignin and hemicellulose which form structural barrier to enzymatic accessibility of cellulose in corn cobs and sawdust. The cellulosic materials were first dried in oven at 65 oC for 24 hours,  and using   solid to liquid ratio of 1:10, the two methods were carried out at resident times ranging from 10 - 40 minutes. The liquid hot water method involved heating the cellulosic materials in water at 120 oC and 1atmosphere in a pressure vessel, and for the second method, the dried cellulosic materials were refluxed in 5 % sulphuric acid at a temperature of 120 oC. Pretreated samples were filtered and liquid fractions were analyzed for the presence of reducing sugars, while solid residues were dried in the oven and weighed to measure the mass lost during pretreatment as a pointer to lignin breakdown. It was observed that the mass lost increased with time for both pretreatment methods, but the liquid hot water pretreatment gave higher lignin and hemicellulose removal when compared to the sulphuric acid pre-treatment. The pretreated materials were hydrolyzed with two combinations of commercial enzymes namely cellulase/ hemicellulase and cellulase/β glucosidase. The reducing sugar was measured using Dinitrosalycilic acid (DNSA method and the sugar yields from corn cobs were higher than that of sawdust when subjected to similar process conditions, and the enzyme combination of cellulase/glucosidase gave higher yields of reducing sugars.  A model equation which describes the hydrolysis process was developed from first principles and the experimental data

Different physical and chemical pretreatments of wheat straw for enhanced biobutanol production in simultaneous saccharification and fermentation

Energy Technology Data Exchange (ETDEWEB)

Thirmal, Chumangalah; Dahman, Yaser [Department of Chemical Engineering, Ryerson University, Toronto, Ontario M5B 2K3 (Canada)

2011-07-01

The objective of this study is to increase butanol product yields using wheat straw as the biomass. First this study examined different pretreatment and saccharification processes to obtain the maximum sugar concentration. Three different physical and chemical pretreatment methods for the wheat straws were examined in the present work in comparison with physical pretreatment alone as a reference. This included water, acidic, and alkaline pretreatment. For all cases, physical pretreatment represented by 1 mm size reduction of the straws was applied prior to each pretreatment. Results showed that 13.91 g/L glucose concentration was produced from saccharification with just the physical pretreatment (i.e., no chemical pretreatment). This represented {approx}5-20 % lower sugar release in saccharification compared to the other three pretreatment processes. Saccharification with acid pretreatment obtained the highest sugar concentrations, which were 18.77 g/L glucose and 12.19 g/L xylose. Second this study produced butanol from simultaneous saccharification and fermentation (SSF) using wheat straw hydrolysate and Clostridium beijerinckii BA101. Water pretreatment was applied to separate lignin and polysaccharides from the wheat straw. Physical pretreatment was applied prior to water pretreatment where, wheat straw was grounded into fine particles less than 1 mm size. Another experiment was conducted where physical pretreatment was applied alone prior to SSF (i.e. no chemical pretreatment was applied). Both processes converted more than 10% of wheat straw into butanol product. This was 2% higher than previous studies. The results illustrated that SSF with physical pretreatment alone obtained 2.61 g/L butanol.

Wet Oxidation Pretreatment of Tobacco Stalks and Orange Waste for Bioethanol Production. Preliminary results

DEFF Research Database (Denmark)

Martin, Carlos; Fernandez, Teresa; Garcia, Ariel

2009-01-01

Wet oxidation (WO) was used as a pretreatment method prior to enzymatic hydrolysis of tobacco stalks and orange waste. The pretreatment, performed at 195 degrees C and an oxygen pressure of 1.2 MPa, for 15 min, in the presence of Na2CO3, increased the cellulose content of the materials and gave c...

Chemical Pretreatment Methods for the Production of Cellulosic Ethanol: Technologies and Innovations

Directory of Open Access Journals (Sweden)

Edem Cudjoe Bensah

2013-01-01

Full Text Available Pretreatment of lignocellulose has received considerable research globally due to its influence on the technical, economic and environmental sustainability of cellulosic ethanol production. Some of the most promising pretreatment methods require the application of chemicals such as acids, alkali, salts, oxidants, and solvents. Thus, advances in research have enabled the development and integration of chemical-based pretreatment into proprietary ethanol production technologies in several pilot and demonstration plants globally, with potential to scale-up to commercial levels. This paper reviews known and emerging chemical pretreatment methods, highlighting recent findings and process innovations developed to offset inherent challenges via a range of interventions, notably, the combination of chemical pretreatment with other methods to improve carbohydrate preservation, reduce formation of degradation products, achieve high sugar yields at mild reaction conditions, reduce solvent loads and enzyme dose, reduce waste generation, and improve recovery of biomass components in pure forms. The use of chemicals such as ionic liquids, NMMO, and sulphite are promising once challenges in solvent recovery are overcome. For developing countries, alkali-based methods are relatively easy to deploy in decentralized, low-tech systems owing to advantages such as the requirement of simple reactors and the ease of operation.

Enrichment of the hydrogen-producing microbial community from marine intertidal sludge by different pretreatment methods

Energy Technology Data Exchange (ETDEWEB)

Liu, Hongyan [Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Shinan District, Qingdao 266071, Shandong (China); College of Marine Science and Engineering, University of Science and Technology, Tianjin 300457 (China); Graduate School, Chinese Academy of Sciences, Beijing 100039 (China); Wang, Guangce [Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Shinan District, Qingdao 266071, Shandong (China); College of Marine Science and Engineering, University of Science and Technology, Tianjin 300457 (China); Zhu, Daling; Pan, Guanghua [College of Marine Science and Engineering, University of Science and Technology, Tianjin 300457 (China)

2009-12-15

To determine the effects of pretreatment on hydrogen production and the hydrogen-producing microbial community, we treated the sludge from the intertidal zone of a bathing beach in Tianjin with four different pretreatment methods, including acid treatment, heat-shock, base treatment as well as freezing and thawing. The results showed that acid pretreatment significantly promoted the hydrogen production by sludge and provided the highest efficiency of hydrogen production among the four methods. The efficiency of the hydrogen production of the acid-pretreated sludge was 0.86 {+-} 0.07 mol H{sub 2}/mol glucose (mean {+-} S.E.), whereas that of the sludge treated with heat-shock, freezing and thawing, base method and control was 0.41 {+-} 0.03 mol H{sub 2}/mol glucose, 0.17 {+-} 0.01 mol H{sub 2}/mol glucose, 0.11 {+-} 0.01 mol H{sub 2}/mol glucose and 0.20 {+-} 0.04 mol H{sub 2}/mol glucose, respectively. The result of denaturing gradient gel electrophoresis (DGGE) showed that pretreatment methods altered the composition of the microbial community that accounts for hydrogen production. Acid and heat pretreatments were favorable to enrich the dominant hydrogen-producing bacterium, i.e. Clostridium sp., Enterococcus sp. and Bacillus sp. However, besides hydrogen-producing bacteria, much non-hydrogen-producing Lactobacillus sp. was also found in the sludge pretreated with base, freezing and thawing methods. Therefore, based on our results, we concluded that, among the four pretreatment methods using acid, heat-shock, base or freezing and thawing, acid pretreatment was the most effective method for promoting hydrogen production of microbial community. (author)

Electrochemical pretreatment of waste activated sludge: effect of process conditions on sludge disintegration degree and methane production.

Science.gov (United States)

Ye, Caihong; Yuan, Haiping; Dai, Xiaohu; Lou, Ziyang; Zhu, Nanwen

2016-11-01

Waste activated sludge (WAS) requires a long digestion time because of a rate-limiting hydrolysis step - the first phase of anaerobic digestion (AD). Pretreatment can be used prior to AD to facilitate the hydrolysis step and improve the efficiency of WAS digestion. This study evaluated a novel application of electrochemical (EC) technology employed as the pretreatment method prior to AD of WAS, focusing on the effect of process conditions on sludge disintegration and subsequent AD process. A superior process condition of EC pretreatment was obtained by reaction time of 30 min, electrolysis voltage of 20 V, and electrode distance of 5 cm, under which the disintegration degree of WAS ranged between 9.02% and 9.72%. In the subsequent batch AD tests, 206 mL/g volatile solid (VS) methane production in EC pretreated sludge was obtained, which was 20.47% higher than that of unpretreated sludge. The AD time was 19 days shorter for EC pretreated sludge compared to the unpretreated sludge. Additionally, the EC + AD reactor achieved 41.84% of VS removal at the end of AD. The analysis of energy consumption showed that EC pretreatment could be effective in enhancing sludge AD with reduced energy consumption when compared to other pretreatment methods.

Improving the sludge disintegration efficiency of sonication by combining with alkalization and thermal pre-treatment methods.

Science.gov (United States)

Şahinkaya, S; Sevimli, M F; Aygün, A

2012-01-01

One of the most serious problems encountered in biological wastewater treatment processes is the production of waste activated sludge (WAS). Sonication, which is an energy-intensive process, is the most powerful sludge pre-treatment method. Due to lack of information about the combined pre-treatment methods of sonication, the combined pre-treatment methods were investigated and it was aimed to improve the disintegration efficiency of sonication by combining sonication with alkalization and thermal pre-treatment methods in this study. The process performances were evaluated based on the quantities of increases in soluble chemical oxygen demand (COD), protein and carbohydrate. The releases of soluble COD, carbohydrate and protein by the combined methods were higher than those by sonication, alkalization and thermal pre-treatment alone. Degrees of sludge disintegration in various options of sonication were in the following descending order: sono-alkalization > sono-thermal pre-treatment > sonication. Therefore, it was determined that combining sonication with alkalization significantly improved the sludge disintegration and decreased the required energy to reach the same yield by sonication. In addition, effects on sludge settleability and dewaterability and kinetic mathematical modelling of pre-treatment performances of these methods were investigated. It was proven that the proposed model accurately predicted the efficiencies of ultrasonic pre-treatment methods.

Technological pretreatment of the synchysite non-oxidized ore

Science.gov (United States)

Munkhtsetseg, B.; Burmaa, G.

2013-06-01

Mongolia has rich deposits of rare, precious, and poly-metallic ores. Nowadays, it is important to research separation of rare earth elements oxides concentrates from the ores, analyze their unique physical chemical characteristics, and purified it. Our investigation on raw materials focuses on rare earth non-oxidized ores. Main mineral in this rock sample is Synchysite (LnCa(CO3)2F. We did technological and thermal pretreatment: direct sulphurization (H2SO4), sulphurization with subsequent roasting (800°C+H2SO4), sulphurization prior to roasting (H2SO4+650°C). Sulphurization method based on dissolution of rare earth mineral into sulfuric acid (93%) according to the reaction. The amount of rare earth element oxides is almost 10 times greater (29.16%) after direct sulphurization process, almost 8 times greater (21.14%) after sulphurization with subsequent roasting, and almost 20 times greater (44.62%) after sulphurization prior to roasting process. After those technological pretreatment raw material's micro elements Thorium and Uranium contents are reduced as follows: H2SO4>800°C+H2SO4>H2SO4+650°C. These results show that cerium group rare earth elements have very good solubility in water at +2°C temperature and decreasing micro elements content uranium and thorium good pretreatment condition is prior to roasting (H2SO4+650°C) of synchysite non-oxidized ore.

Pretreatment technologies for industrial effluents: Critical review on bioenergy production and environmental concerns.

Science.gov (United States)

Prabakar, Desika; Suvetha K, Subha; Manimudi, Varshini T; Mathimani, Thangavel; Kumar, Gopalakrishnan; Rene, Eldon R; Pugazhendhi, Arivalagan

2018-07-15

The implementation of different pretreatment techniques and technologies prior to effluent discharge is a direct result of the inefficiency of several existing wastewater treatment methods. A majority of the industrial sectors have known to cause severe negative effects on the environment. The five major polluting industries are the paper and pulp mills, coal manufacturing facilities, petrochemical, textile and the pharmaceutical sectors. Pretreatment methods have been widely used in order to lower the toxicity levels of effluents and comply with environmental standards. In this review, the possible environmental benefits and concerns of adopting different pretreatment technologies for renewable energy production and product/resource recovery has been reviewed and discussed. Copyright © 2018 Elsevier Ltd. All rights reserved.

Biomass pretreatment

Science.gov (United States)

Hennessey, Susan Marie; Friend, Julie; Elander, Richard T; Tucker, III, Melvin P

2013-05-21

A method is provided for producing an improved pretreated biomass product for use in saccharification followed by fermentation to produce a target chemical that includes removal of saccharification and or fermentation inhibitors from the pretreated biomass product. Specifically, the pretreated biomass product derived from using the present method has fewer inhibitors of saccharification and/or fermentation without a loss in sugar content.

Thermal and enzymatic pretreatment of sludge containing phthalate esters prior to mesophilic anaerobic digestion

DEFF Research Database (Denmark)

Gavala, Hariklia N.; Yenal, U.; Ahring, Birgitte Kiær

2004-01-01

The present study aimed at investigating the effect of thermal pretreatment of sludge at 70degreesC on the anaerobic degradation of three commonly found phthalic acid esters (PAE): di-ethyl phthalate (DEP), di-butyl phthalate (DBP), and di-ethylhexyl phthalate (DEHP). Also, the enzymatic treatment...... at 28degreesC with a commercial lipase was studied as a way to enhance PAE removal. Pretreatment at 70degreesC of the sludge containing PAE negatively influenced the anaerobic biodegradability of phthalate esters at 37degreesC. The observed reduction of PAE biodegradation rates after the thermal...... pretreatment was found to be proportional to the PAE solubility in water: the higher the solubility, the higher the percentage of the reduction (DEP > DBP > DEHP). PAE were slowly degraded during the pretreatment at 70degreesC, yet this was probably due to physicochemical reactions than to microbial...

Analytical Methods for Biomass Characterization during Pretreatment and Bioconversion

Energy Technology Data Exchange (ETDEWEB)

Pu, Yunqiao [ORNL; Meng, Xianzhi [University of Tennessee, Knoxville (UTK); Yoo, Chang Geun; Li, Mi; Ragauskas, Arthur J [ORNL

2016-01-01

Lignocellulosic biomass has been introduced as a promising resource for alternative fuels and chemicals because of its abundance and complement for petroleum resources. Biomass is a complex biopolymer and its compositional and structural characteristics largely vary depending on its species as well as growth environments. Because of complexity and variety of biomass, understanding its physicochemical characteristics is a key for effective biomass utilization. Characterization of biomass does not only provide critical information of biomass during pretreatment and bioconversion, but also give valuable insights on how to utilize the biomass. For better understanding biomass characteristics, good grasp and proper selection of analytical methods are necessary. This chapter introduces existing analytical approaches that are widely employed for biomass characterization during biomass pretreatment and conversion process. Diverse analytical methods using Fourier transform infrared (FTIR) spectroscopy, gel permeation chromatography (GPC), and nuclear magnetic resonance (NMR) spectroscopy for biomass characterization are reviewed. In addition, biomass accessibility methods by analyzing surface properties of biomass are also summarized in this chapter.

Comparison of manual and automated pretreatment methods for AMS radiocarbon dating of plant fossils

Science.gov (United States)

Bradley, L.A.; Stafford, Thomas W.

1994-01-01

A new automated pretreatment system for the preparation of materials submitted for accelerator mass spectrometry (AMS) analysis is less time-consuming and results in a higher sample yield. The new procedure was tested using two groups of plant fossils: one group was pretreated using the traditional method, and the second, using the automated pretreatment apparatus. The time it took to complete the procedure and the amount of sample material remaining were compared. The automated pretreatment apparatus proved to be more than three times faster and, in most cases, produced a higher yield. A darker discoloration of the KOH solutions was observed indicating that the automated system is more thorough in removing humates from the specimen compared to the manual method. -Authors

COMPARISON OF PRETREATMENT STRATEGIES FOR CONVERSION OF COCONUT HUSK FIBER TO FERMENTABLE SUGARS

Directory of Open Access Journals (Sweden)

Teck Y. Ding,

2012-02-01

Full Text Available In the present study, coconut husk was employed as biomass feedstock for production of bioethanol, due to its abundance in Malaysia. Due to the complex structures of coconut husk, a pretreatment process is crucial in extracting fermentable sugars from the embedded cellulose matrix for subsequent ethanol fermentation process. The ground coconut husk was subjected to three different pretreatment processes inclusive of thermal, chemical, and microwave-assisted-alkaline techniques, prior to enzymatic hydrolysis and fermentation process. The composition profile of coconut husk was significantly altered upon the microwave-assisted-alkaline treatment as compared to the untreated sample, with the cellulose content increasing from 18-21% to 38-39% while lignin content decreased from 46-53% to 31-33%. Among the pretreatment methods applied, enzymatic hydrolysis of coconut husk pretreated by microwave-assisted-alkaline method recorded the highest yield of fermentable sugars, 0.279 g sugar/g substrate. SEM imaging showed the obvious and significant disruption of coconut husks’ structure after microwave-assisted-alkaline pretreatment. In conclusion, by employing suitable pretreatment technique in treating the lignocellulosic materials of coconut husk, the extracted fermentable sugar is a potential substrate for bioethanol production.

Evaluation of lime and hydrothermal pretreatments for efficient enzymatic hydrolysis of raw sugarcane bagasse.

Science.gov (United States)

Grimaldi, Maira Prearo; Marques, Marina Paganini; Laluce, Cecília; Cilli, Eduardo Maffud; Sponchiado, Sandra Regina Pombeiro

2015-01-01

Ethanol production from sugarcane bagasse requires a pretreatment step to disrupt the cellulose-hemicellulose-lignin complex and to increase biomass digestibility, thus allowing the obtaining of high yields of fermentable sugars for the subsequent fermentation. Hydrothermal and lime pretreatments have emerged as effective methods in preparing the lignocellulosic biomass for bioconversion. These pretreatments are advantageous because they can be performed under mild temperature and pressure conditions, resulting in less sugar degradation compared with other pretreatments, and also are cost-effective and environmentally sustainable. In this study, we evaluated the effect of these pretreatments on the efficiency of enzymatic hydrolysis of raw sugarcane bagasse obtained directly from mill without prior screening. In addition, we evaluated the structure and composition modifications of this bagasse after lime and hydrothermal pretreatments. The highest cellulose hydrolysis rate (70 % digestion) was obtained for raw sugarcane bagasse pretreated with lime [0.1 g Ca(OH)2/g raw] for 60 min at 120 °C compared with hydrothermally pretreated bagasse (21 % digestion) under the same time and temperature conditions. Chemical composition analyses showed that the lime pretreatment of bagasse promoted high solubilization of lignin (30 %) and hemicellulose (5 %) accompanied by a cellulose accumulation (11 %). Analysis of pretreated bagasse structure revealed that lime pretreatment caused considerable damage to the bagasse fibers, including rupture of the cell wall, exposing the cellulose-rich areas to enzymatic action. We showed that lime pretreatment is effective in improving enzymatic digestibility of raw sugarcane bagasse, even at low lime loading and over a short pretreatment period. It was also demonstrated that this pretreatment caused alterations in the structure and composition of raw bagasse, which had a pronounced effect on the enzymes accessibility to the

Effect of seed collection times and pretreatment methods on ...

African Journals Online (AJOL)

STORAGESEVER

2008-08-18

Aug 18, 2008 ... Several basic methods are used to overcome seed- coat dormancy in ... The experiment on seed pretreatment were conducted at Forestry. Research ..... applicability to rural areas where these trees are planted may be limited. .... Forestry. Research News: Indicators and Tools for Restoration & Sustainable.

Benefits of hyperbaric oxygen pretreatment for decompression sickness in Bama pigs.

Science.gov (United States)

Qing, Long; Yi, Hong-Jie; Wang, Ye-Wei; Zhou, Quan; Ariyadewa, Dinesh K; Xu, Wei-Gang

2018-03-07

Decompression sickness (DCS) occurs when ambient pressure is severely reduced during diving and aviation. Hyperbaric oxygen (HBO) pretreatment has been shown to exert beneficial effects on DCS in rats via heat-shock proteins (HSPs). We hypothesized that HBO pretreatment will also reduce DCS via HSPs in swine models. In the first part of our investigation, six swine were subjected to a session of HBO treatment. HSP32, 60, 70 and 90 were detected, before and at 6, 12, 18, 24 and 30 h following exposure in lymphocytes. In the second part of our investigation, another 10 swine were randomly assigned into two groups (five per group). All swine were subjected to two simulated air dives in a hyperbaric chamber with an interval of 7 days. Eighteen hours before each dive, the swine were pretreated with HBO or air: the first group received air pretreatment prior to the first dive and HBO pretreatment prior to the second; the second group were pretreated with HBO first and then air. Bubble loads, skin lesions, inflammation and endothelial markers were detected after each dive. In lymphocytes, all HSPs increased significantly ( P <0.05), with the greatest expression appearing at 18 h for HSP32 and 70. HBO pretreatment significantly reduced all the determined changes compared with air pretreatment. The results demonstrate that a single exposure to HBO 18 h prior to diving effectively protects against DCS in the swine model, possibly via induction of HSPs. © 2018. Published by The Company of Biologists Ltd.

Study on the pre-treatment of oxidized zinc ore prior to flotation

Science.gov (United States)

He, Dong-sheng; Chen, Yun; Xiang, Ping; Yu, Zheng-jun; Potgieter, J. H.

2018-02-01

The pre-treatment of zinc oxide bearing ores with high slime content is important to ensure that resources are utilized optimally. This paper reports an improved process using hydrocyclone de-sliming, dispersion reagents, and magnetic removal of iron minerals for the pre-treatment of zinc oxide ore with a high slime and iron content, and the benefits compared to traditional technologies are shown. In addition, this paper investigates the damage related to fine slime and iron during zinc oxide flotation, the necessity of using hydrocyclone de-sliming together with dispersion reagents to alleviate the influence of slime, and interactions among hydrocyclone de-sliming, reagent dispersion, and magnetic iron removal. Results show that under optimized operating conditions the entire beneficiation technology results in a flotation concentrate with a Zn grade of 34.66% and a recovery of 73.41%.

Dry ice blasting as a substitution for the conventional electroplating pre-treatments

Directory of Open Access Journals (Sweden)

Uhlmann Eckart

2016-01-01

Full Text Available For high quality electroplated products, surfaces must be thoroughly pre-treated. For this purpose electroplating currently needs a variety of chemical baths. The used chemicals are injurious to health and harmful to the environment. In addition, the conventional pre-treatment has a long process time which results in high costs. Dry ice blasting alone or in combination with other processes has the potential to completely substitute these conventional pre-treatment processes. Three process sequences as pre-treatment methods prior to electroplating were investigated on the aluminium alloys AlSi12 and AlMg3. The used processes are dry ice blasting, tempering during dry ice blasting and glass bead blasting followed by dry ice blasting. The influence of the parameters on the surface roughness, surface topography and surface tension of the workpieces was examined. A model to describe the correlation between the dry ice blasting parameters and surface parameters was developed. Finally, an adhesion test of electroplated specimen was conducted in order to determine the suitability of these alternative pre-treatment processes.

Application of ceramic membranes for seawater reverse osmosis (SWRO) pre-treatment

KAUST Repository

Hamad, Juma; Ha, Changwon; Kennedy, Maria Dolores; Amy, Gary L.

2013-01-01

and particulate fouling materials (algae, suspended and colloidal particles). Also, a pre-treatment barrier reduces organics and provides better feed water quality for RO membranes. MF and UF pre-treatment prior to SWRO provides Low Silt Density Index (SDI) values

Thermochemical pretreatments for enhancing succinic acid production from industrial hemp (Cannabis sativa L.)

DEFF Research Database (Denmark)

Gunnarsson, Ingólfur Bragi; Kuglarz, Mariusz; Karakashev, Dimitar Borisov

2015-01-01

The aim of this study was to develop an efficient thermochemical method for treatment of industrial hemp biomass, in order to increase its bioconversion to succinic acid. Industrial hemp was subjected to various thermochemical pretreatments using 0-3% H2SO4, NaOH or H2O2 at 121-180°C prior...... to enzymatic hydrolysis. The influence of the different pretreatments on hydrolysis and succinic acid production by Actinobacillus succinogenes 130Z was investigated in batch mode, using anaerobic bottles and bioreactors. Enzymatic hydrolysis and fermentation of hemp material pretreated with 3% H2O2 resulted...... in the highest overall sugar yield (73.5%), maximum succinic acid titer (21.9gL-1), as well as the highest succinic acid yield (83%). Results obtained clearly demonstrated the impact of different pretreatments on the bioconversion efficiency of industrial hemp into succinic acid....

Pretreatment methods to obtain pumpable high solid loading wood–water slurries for continuous hydrothermal liquefaction systems

DEFF Research Database (Denmark)

Dãrãbana, Iulia-Maria; Rosendahl, Lasse Aistrup; Pedersen, Thomas Helmer

2015-01-01

Feedstock pretreatment is a prerequisite step for continuous processing of lignocellulosic biomass through HTL, in order to facilitate the pumpability of biomass aqueous slurries. Until now, HTL feedstock pumpability could only be achieved at solid mass content below 15%. In this work, two...... pretreatment methods to obtain wood-based slurries with more than 20% solid mass content, for continuous processing in HTL systems, are proposed. The effect of biomass particle size and pretreatment method on the feedstock pumpability is analyzed. The experimental results show that pumpable wood-based slurries...

A pretreatment method for grain size analysis of red mudstones

Science.gov (United States)

Jiang, Zaixing; Liu, Li'an

2011-11-01

Traditional sediment disaggregation methods work well for loose mud sediments, but not for tightly cemented mudstones by ferric oxide minerals. In this paper, a new pretreatment method for analyzing the grain size of red mudstones is presented. The experimental samples are Eocene red mudstones from the Dongying Depression, Bohai Bay Basin. The red mudstones are composed mainly of clay minerals, clastic sediments and ferric oxides that make the mudstones red and tightly compacted. The procedure of the method is as follows. Firstly, samples of the red mudstones were crushed into fragments with a diameter of 0.6-0.8 mm in size; secondly, the CBD (citrate-bicarbonate-dithionite) treatment was used to remove ferric oxides so that the cementation of intra-aggregates and inter-aggregates became weakened, and then 5% dilute hydrochloric acid was added to further remove the cements; thirdly, the fragments were further ground with a rubber pestle; lastly, an ultrasonicator was used to disaggregate the samples. After the treatment, the samples could then be used for grain size analysis or for other geological analyses of sedimentary grains. Compared with other pretreatment methods for size analysis of mudstones, this proposed method is more effective and has higher repeatability.

An Adaptively Accelerated Bayesian Deblurring Method with Entropy Prior

Directory of Open Access Journals (Sweden)

Yong-Hoon Kim

2008-05-01

Full Text Available The development of an efficient adaptively accelerated iterative deblurring algorithm based on Bayesian statistical concept has been reported. Entropy of an image has been used as a “prior” distribution and instead of additive form, used in conventional acceleration methods an exponent form of relaxation constant has been used for acceleration. Thus the proposed method is called hereafter as adaptively accelerated maximum a posteriori with entropy prior (AAMAPE. Based on empirical observations in different experiments, the exponent is computed adaptively using first-order derivatives of the deblurred image from previous two iterations. This exponent improves speed of the AAMAPE method in early stages and ensures stability at later stages of iteration. In AAMAPE method, we also consider the constraint of the nonnegativity and flux conservation. The paper discusses the fundamental idea of the Bayesian image deblurring with the use of entropy as prior, and the analytical analysis of superresolution and the noise amplification characteristics of the proposed method. The experimental results show that the proposed AAMAPE method gives lower RMSE and higher SNR in 44% lesser iterations as compared to nonaccelerated maximum a posteriori with entropy prior (MAPE method. Moreover, AAMAPE followed by wavelet wiener filtering gives better result than the state-of-the-art methods.

Anaerobic digestion of waste activated sludge—comparison of thermal pretreatments with thermal inter-stage treatments

DEFF Research Database (Denmark)

Bangsø Nielsen, Henrik; Thygesen, Anders; Thomsen, Anne Belinda

2011-01-01

BACKGROUND: Treatment methods for improved anaerobic digestion (AD) of waste activated sludge were evaluated. Pretreatments at moderate thermal (water bath at 80 °C), high thermal (loop autoclave at 130–170 °C) and thermo-chemical (170 °C/pH 10) conditions prior to AD in batch vials (40 days/37 °....... CONCLUSION: Thermal treatment of waste activated sludge for improved anaerobic digestion seems more effective when applied as an inter-stage treatment rather than a pretreatment. Copyright © 2010 Society of Chemical Industry...

Comparison of different pretreatment methods for lignocellulosic materials. Part I: conversion of rye straw to valuable products.

Science.gov (United States)

Ingram, Thomas; Wörmeyer, Kai; Lima, Juan Carlos Ixcaraguá; Bockemühl, Vera; Antranikian, Garabed; Brunner, Gerd; Smirnova, Irina

2011-04-01

The conversion of lignocellulose to valuable products requires I: a fractionation of the major components hemicellulose, cellulose, and lignin, II: an efficient method to process these components to higher valued products. The present work compares liquid hot water (LHW) pretreatment to the soda pulping process and to the ethanol organosolv pretreatment using rye straw as a single lignocellulosic material. The organosolv pretreated rye straw was shown to require the lowest enzyme loading in order to achieve a complete saccharification of cellulose to glucose. At biomass loadings of up to 15% (w/w) cellulose conversion of LHW and organosolv pretreated lignocellulose was found to be almost equal. The soda pulping process shows lower carbohydrate and lignin recoveries compared to the other two processes. In combination with a detailed analysis of the different lignins obtained from the three pretreatment methods, this work gives an overview of the potential products from different pretreatment processes. Copyright © 2011 Elsevier Ltd. All rights reserved.

Utilization of microwave and ultrasound pretreatments in the production of bioethanol from corn

Energy Technology Data Exchange (ETDEWEB)

Nikolic, Svetlana; Mojovic, Ljiljana; Rakin, Marica [University of Belgrade, Faculty of Technology and Metallurgy, Belgrade (Serbia); Pejin, Dusanka; Pejin, Jelena [University of Novi Sad, Faculty of Technology, Novi Sad (Serbia)

2011-08-15

Bioethanol production by simultaneous saccharification and fermentation (SSF) of corn meal by Saccharomyces cerevisiae var. ellipsoideus yeast in a batch system with prior ultrasound or microwave treatment was studied. The optimal duration of the pretreatments and the SSF process kinetics were assessed and determined. Also, the effect of ultrasound and microwave pretreatments on ethanol yield and productivity was investigated. An optimal duration of 5 min was determined for both pretreatments. Ultrasonic and microwave pretreatments effectively increased the glucose concentration obtained after liquefaction by 6.82 and 8.48%, respectively, compared to untreated control sample. Also, both pretreatments improved ethanol yield and productivity during the SSF process. Ultrasound and microwave pretreatments increased the maximum ethanol concentration produced in the SSF process by 11.15 and 13.40% (compared to the control sample), respectively. The application of microwave pretreatment resulted in higher glucose release during liquefaction and consequently in higher ethanol concentration, compared to ultrasound pretreatment. A maximum ethanol concentration of 9.91% (w/w) and percentage of theoretical ethanol yield of 92.27% were achieved after 44 h of the SSF process of corn meal with prior microwave treatment. (orig.)

Effects of Pretreatment Methods on Electrodes and SOFC Performance

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Guo-Bin Jung

2014-06-01

Full Text Available Commercially available tapes (anode, electrolyte and paste (cathode were choosen to prepare anode-supported cells for solid oxide fuel cell applications. For both anode-supported cells or electrolyte-supported cells, the anode needs pretreatment to reduce NiO/YSZ to Ni/YSZ to increase its conductivity as well as its catalytic characteristics. In this study, the effects of different pretreatments (open-circuit, closed-circuit on cathode and anodes as well as SOFC performance are investigated. To investigate the influence of closed-circuit pretreatment on the NiO/YSZ anode alone, a Pt cathode is utilized as reference for comparison with the LSM cathode. The characterization of the electrical resistance, AC impedance, and SOFC performance of the resulting electrodes and/or anode-supported cell were carried out. It’s found that the influence of open-circuit pretreatment on the LSM cathode is limited. However, the influence of closed-circuit pretreatment on both the LSM cathode and NiO/YSZ anode and the resulting SOFC performance is profound. The effect of closed-circuit pretreatment on the NiO/YSZ anode is attributed to its change of electronic/pore structure as well as catalytic characteristics. With closed-circuit pretreatment, the SOFC performance improved greatly from the change of LSM cathode (and Pt reference compared to the Ni/YSZ anode.

Safety of intravenous tissue plasminogen activator administration with computed tomography evidence of prior infarction.

Science.gov (United States)

Lyerly, Michael J; Houston, J Thomas; Boehme, Amelia K; Albright, Karen C; Bavarsad Shahripour, Reza; Palazzo, Paola; Alvi, Muhammed; Rawal, Pawan V; Kapoor, Niren; Sisson, April; Alexandrov, Anne W; Alexandrov, Andrei V

2014-07-01

Prior stroke within 3 months excludes patients from thrombolysis; however, patients may have computed tomography (CT) evidence of prior infarct, often of unknown time of origin. We aimed to determine if the presence of a previous infarct on pretreatment CT is a predictor of hemorrhagic complications and functional outcomes after the administration of intravenous (IV) tissue plasminogen activator (tPA). We retrospectively analyzed consecutive patients treated with IV tPA at our institution from 2009-2011. Pretreatment CTs were reviewed for evidence of any prior infarct. Further review determined if any hemorrhagic transformation (HT) or symptomatic intracerebral hemorrhage (sICH) were present on repeat CT or magnetic resonance imaging. Outcomes included sICH, any HT, poor functional outcome (modified Rankin Scale score of 4-6), and discharge disposition. Of 212 IV tPA-treated patients, 84 (40%) had evidence of prior infarct on pretreatment CT. Patients with prior infarcts on CT were older (median age, 72 versus 65 years; P=.001) and had higher pretreatment National Institutes of Health Stroke Scale scores (median, 10 versus 7; P=.023). Patients with prior infarcts on CT did not experience more sICH (4% versus 2%; P=.221) or any HT (18% versus 14%; P=.471). These patients did have a higher frequency of poor functional outcome at discharge (82% versus 50%; P<.001) and were less often discharged to home or inpatient rehabilitation center (61% versus 73%; P=.065). Visualization of prior infarcts on pretreatment CT did not predict an increased risk of sICH in our study and should not be viewed as a reason to withhold systemic tPA treatment after clinically evident strokes within 3 months were excluded. Published by Elsevier Inc.

Analysis of head motion prior to and during proton beam therapy

International Nuclear Information System (INIS)

Schulte, Reinhard W.; Fargo, Ramiz A.; Meinass, Helmut J.; Slater, Jerry D.; Slater, James M.

2000-01-01

Purpose: We report on the use of a noninvasive patient motion monitoring system to evaluate the amount of head motion prior to and during proton radiation therapy sessions. Methods and Materials: Two optical displacement sensors, placed close to the patient's head, were used for online monitoring of the head position, with submillimeter accuracy. Motion data, including the difference between start and end position (Dx) and the maximum displacement during the recorded session (Dx-max), were acquired for pretreatment sessions to analyze alignment radiographs, and for treatment sessions. We have recorded 102 pretreatment and 99 treatment sessions in 16 patients immobilized with a thermoplastic mask, and 44 pretreatment and 56 treatment sessions in 13 patients immobilized with vacuum-assisted dental fixation. To avoid incorrect data analysis due to replicate observations, only 1 pretreatment and 1 treatment session per patient were selected at random for statistical comparison of mean or median motion parameters in different subgroups. Results: Both techniques showed similar immobilization efficiencies. The median Dx and Dx-max values were 0.18 mm and 0.46 mm, respectively, for 16 treatment sessions with mask immobilization, and 0.22 mm and 0.50 mm, respectively, for 13 treatment sessions with dental immobilization. Motion parameters for pretreatment and treatment sessions were not statistically different. Conclusion: Online verification of patient's head motion is feasible and provides valuable data for confirmation of proper treatment delivery in individual patients, as well as for the evaluation of different immobilization methods

Thermal pretreatment of the solid fraction of manure: Impact on the biogas reactor performance and microbial community

DEFF Research Database (Denmark)

Mladenovska, Z; Hartmann, H.; Kvist, T.

2006-01-01

Application of thermal treatment at 100-140 degrees C as a pretreatment method prior to anaerobic digestion of a mixture of cattle and swine manure was investigated. In a batch test, biogasification of manure with thermally pretreated solid fraction proceeded faster and resulted in the increase...... of methane yield. The performances of two thermophilic continuously stirred tank reactors (CSTR) treating manure with solid fraction pretreated for 40 minutes at 140 degrees C and non-treated manure were compared. The digester fed with the thermally pretreated manure had a higher methane productivity...... and butyrate - was low. The kinetic parameters of the VFA conversion revealed a reduced affinity of the microbial community from the CSTR fed with thermally pre-treated manure for acetate, propionate and butyrate. The bacterial and archaeal populations identified by t-RLFP analysis of 16S rRNA genes were found...

Waste washing pre-treatment of municipal and special waste.

Science.gov (United States)

Cossu, Raffaello; Lai, Tiziana; Pivnenko, Kostyantyn

2012-03-15

Long-term pollution potential in landfills is mainly related to the quality of leachate. Waste can be conveniently treated prior to landfilling with an aim to minimizing future emissions. Washing of waste represents a feasible pre-treatment method focused on controlling the leachable fraction of residues and relevant impact. In this study, non-recyclable plastics originating from source segregation, mechanical-biological treated municipal solid waste (MSW), bottom ash from MSW incineration and automotive shredder residues (ASR) were treated and the removal efficiency of washing pre-treatment prior to landfilling was evaluated. Column tests were performed to simulate the behaviour of waste in landfill under aerobic and anaerobic conditions. The findings obtained revealed how waste washing treatment (WWT) allowed the leachability of contaminants from waste to be reduced. Removal rates exceeding 65% were obtained for dissolved organic carbon (DOC), chemical oxygen demand (COD) and Total Kjeldahl Nitrogen (TKN). A percentage decrease of approximately 60% was reached for the leachable fraction of chlorides, sulphates, fluoride and metals, as proved by a reduction in electric conductivity values (70%). Copyright © 2011 Elsevier B.V. All rights reserved.

Thermochemical pretreatments for enhancing succinic acid production from industrial hemp (Cannabis sativa L.).

Science.gov (United States)

Gunnarsson, Ingólfur B; Kuglarz, Mariusz; Karakashev, Dimitar; Angelidaki, Irini

2015-04-01

The aim of this study was to develop an efficient thermochemical method for treatment of industrial hemp biomass, in order to increase its bioconversion to succinic acid. Industrial hemp was subjected to various thermochemical pretreatments using 0-3% H2SO4, NaOH or H2O2 at 121-180°C prior to enzymatic hydrolysis. The influence of the different pretreatments on hydrolysis and succinic acid production by Actinobacillus succinogenes 130Z was investigated in batch mode, using anaerobic bottles and bioreactors. Enzymatic hydrolysis and fermentation of hemp material pretreated with 3% H2O2 resulted in the highest overall sugar yield (73.5%), maximum succinic acid titer (21.9 g L(-1)), as well as the highest succinic acid yield (83%). Results obtained clearly demonstrated the impact of different pretreatments on the bioconversion efficiency of industrial hemp into succinic acid. Copyright © 2015. Published by Elsevier Ltd.

SU-E-T-148: Benchmarks and Pre-Treatment Reviews: A Study of Quality Assurance Effectiveness

International Nuclear Information System (INIS)

Lowenstein, J; Nguyen, H; Roll, J; Walsh, A; Tailor, A; Followill, D

2015-01-01

Purpose: To determine the impact benchmarks and pre-treatment reviews have on improving the quality of submitted clinical trial data. Methods: Benchmarks are used to evaluate a site’s ability to develop a treatment that meets a specific protocol’s treatment guidelines prior to placing their first patient on the protocol. A pre-treatment review is an actual patient placed on the protocol in which the dosimetry and contour volumes are evaluated to be per protocol guidelines prior to allowing the beginning of the treatment. A key component of these QA mechanisms is that sites are provided timely feedback to educate them on how to plan per the protocol and prevent protocol deviations on patients accrued to a protocol. For both benchmarks and pre-treatment reviews a dose volume analysis (DVA) was performed using MIM softwareTM. For pre-treatment reviews a volume contour evaluation was also performed. Results: IROC Houston performed a QA effectiveness analysis of a protocol which required both benchmarks and pre-treatment reviews. In 70 percent of the patient cases submitted, the benchmark played an effective role in assuring that the pre-treatment review of the cases met protocol requirements. The 35 percent of sites failing the benchmark subsequently modified there planning technique to pass the benchmark before being allowed to submit a patient for pre-treatment review. However, in 30 percent of the submitted cases the pre-treatment review failed where the majority (71 percent) failed the DVA. 20 percent of sites submitting patients failed to correct their dose volume discrepancies indicated by the benchmark case. Conclusion: Benchmark cases and pre-treatment reviews can be an effective QA tool to educate sites on protocol guidelines and to minimize deviations. Without the benchmark cases it is possible that 65 percent of the cases undergoing a pre-treatment review would have failed to meet the protocols requirements.Support: U24-CA-180803

Oxygen status of cervical cancers prior and during definitive radiotherapy: possible impact of pretreatment with INF-α-2a/retinol acid on oxygenation

International Nuclear Information System (INIS)

Haensgen, Gabriele; Haensgen, Klaus; Dunst, Juergen

1996-01-01

Objective: Modern techniques have raised the possibility to measure intratumoral pO 2 with needle electrodes. We have investigated the oxygenation status of cervical cancers in patients undergoing definitive radiotherapy. Materials and Methods: From July 1995 through February 1996, 28 patients with squamous cell carcinoma of the cervix uteri FIGO II/III underwent polarographic measurement of tumor oxygenation prior to and during definitive radiotherapy. All received combined external irradiation and HDR-brachytherapy. 14 patients were enrolled in a phase II-protocol and received additional treatment with interferon-alpha-2a (INF-α-2a, daily dose 6x10 6 IU s.c. over 12 days) and cis-retinol acid (cRA, daily dose 1 mg/kg orally) starting 12 days before radiotherapy. During radiotherapy, INF-α-2a was given three times weekly in a dosage of 3x10 6 IU s.c. and cRA in daily doses of 0.5 mg/kg. Tumor oxygenation was measured with an Eppendorf-pO 2 -histograph prior to radiotherapy, after 20Gy and after completion of radiotherapy. Results: We found a broad range of pO 2 -values in the 28 patients. Significant hypoxic areas were detectable in about one third of the patients. The mean and median pO 2 -values did not correlate with tumor stage or tumor volume. At the beginning of radiotherapy, the patients with INF-α-2a/cRA-pretreatment had significant higher mean pO 2 -values as compared to patients without INF-α-2a/cRA-pretreatment: mean pO 2 34.7 ± 25.9 mmHg versus 18.0 ± 9.9 mmHg, p=0.03, median pO 2 28.6 versus 17.3 mmHg). Only two patients had pO 2 -measurements before and after INF-α-2a/cRA-pretreatment; in both the mean pO 2 increased threefold during INF-α-2a/cRA. During radiotherapy, the median pO 2 -value increased in both groups of patients. In patients with primary hypoxia, different patterns of oxygenation were detectable after 20Gy showing persistent hypoxia or an increase in the mean pO 2 . Persistent hypoxia without 'reoxygenation' was associated with

Discrimination of Rice with Different Pretreatment Methods by Using a Voltammetric Electronic Tongue

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Li Wang

2015-07-01

Full Text Available In this study, an application of a voltammetric electronic tongue for discrimination and prediction of different varieties of rice was investigated. Different pretreatment methods were selected, which were subsequently used for the discrimination of different varieties of rice and prediction of unknown rice samples. To this aim, a voltammetric array of sensors based on metallic electrodes was used as the sensing part. The different samples were analyzed by cyclic voltammetry with two sample-pretreatment methods. Discriminant Factorial Analysis was used to visualize the different categories of rice samples; however, radial basis function (RBF artificial neural network with leave-one-out cross-validation method was employed for prediction modeling. The collected signal data were first compressed employing fast Fourier transform (FFT and then significant features were extracted from the voltammetric signals. The experimental results indicated that the sample solutions obtained by the non-crushed pretreatment method could efficiently meet the effect of discrimination and recognition. The satisfactory prediction results of voltammetric electronic tongue based on RBF artificial neural network were obtained with less than five-fold dilution of the sample solution. The main objective of this study was to develop primary research on the application of an electronic tongue system for the discrimination and prediction of solid foods and provide an objective assessment tool for the food industry.

New pentose dimers with bicyclic moieties from pretreated biomass

DEFF Research Database (Denmark)

Rasmussen, H.; Sørensen, Henrik Rokkjær; Tanner, David Ackland

2017-01-01

In lignocellulosic biorefinery processes involving enzyme catalysed reactions it is a challenge that enzyme inhibiting compounds are generated and liberated during pretreatment of the biomass. In this study the contribution to cellulase inhibition from xylooligosaccharides and newly discovered...... oligophenolic compounds from pilot scale pretreated wheat straw was assessed at two different pretreatment severities. An increase in severity of the pretreatment led to more oligophenol compounds and in turn the total overall cellulase inhibition increased. When the xylooligosaccharides were enzymatically...... degraded prior to cellulose hydrolysis, a relief in cellulase inhibition was observed, but some inhibition remained, suggesting that other components also played a role in inhibition. We propose that these components include dipentoses with bicyclic moieties and feruloylated tripentoses, because LC...

Low Thermal Pretreatment as Method for Increasing the Bioavailability of Organic Matters in Domestic Mixed Sludge

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Seswoya Roslinda

2016-01-01

Full Text Available In practice, primary and secondary sludge are fed into anaerobic digestion. However, the microbial cell exists in secondary sludge are an unfavorable substrate for biodegradation. Thermal pretreatment is proved to increase the bioavailability of organic and improve the biodegradation subsequently. During low thermal pretreatment, both intracellular (within the microbial cell and extracellular (within the polymeric network materials were extracted. This process increases the bioavailability meaning that organic compounds are accessible to the microorganisms for their degradation. This research aims to investigate the effect of thermal pretreatment on domestic mixed sludge disintegration. Domestic mixed sludge was thermally treated at 70°C for various holding times. The pre-thermally treated domestic mixed sludge was measured for protein and carbohydrates following the Lowry Method, and Phenol-Sulphuric Acid Method respectively. DR 6000 UV-Vis spectrophotometer, DRB200 Reactor (digester and COD vial (TNT plus 822 were used for COD determination, based on Reactor Digestion Method approved by USEPA. The results showed that the organic matter in domestic mixed sludge is efficiently solubilised during thermal treatment organic matter. The higher soluble yield for each monitored parameter determined in this study indicated that low thermal pretreatment improve bioavailability.

Enzymatic protein hydrolysates from high pressure-pretreated isolated pea proteins have better antioxidant properties than similar hydrolysates produced from heat pretreatment.

Science.gov (United States)

Girgih, Abraham T; Chao, Dongfang; Lin, Lin; He, Rong; Jung, Stephanie; Aluko, Rotimi E

2015-12-01

Isolated pea protein (IPP) dispersions (1%, w/v) were pretreated with high pressure (HP) of 200, 400, or 600 MPa for 5 min at 24 °C or high temperature (HT) for 30 min at 100 °C prior to hydrolysis with 1% (w/w) Alcalase. HP pretreatment of IPP at 400 and 600 MPa levels led to significantly (P40%) oxygen radical absorption capacity (ORAC) of hydrolysates. 2,2-Diphenyl-1-picrylhydrazyl, superoxide radical and hydroxyl radical scavenging activities of pea protein hydrolysates were also significantly (PProtein hydrolysates from HT IPP showed no ORAC, superoxide or hydroxyl scavenging activity but had significantly (Pprotein hydrolysates had weaker antioxidant properties than glutathione but overall, the HP pretreatment was superior to HT pretreatment in facilitating enzymatic release of antioxidant peptides from IPP. Copyright © 2015 Elsevier Ltd. All rights reserved.

Alkaline sulfide pretreatment of an antimonial refractory Au-Ag ore for improved cyanidation

Science.gov (United States)

Alp, Ibrahim; Celep, Oktay; Deveci, Haci

2010-11-01

This paper presents the alkaline sulfide pretreatment of an antimonial refractory gold and silver ore. In the ore, gold occurs mainly as gold-silver alloys and as associated with quartz and framboidal pyrite grains, and, to a small extent, as the inclusions within antimonial sulfides. Silver is present extensively as antimonial sulfides such as andorite. Alkaline sulfide pretreatment was shown to allow the decomposition of the antimonial sulfide minerals (up to 98% Sb removal) and to remarkably improve the amenability of gold (e.g., from leaching. An increase in reagent concentration (1-4 mol/L Na2S or NaOH) and temperature (20-80°C), and a decrease in particle size seem to produce an enhancing effect on metal extraction. These findings suggest that alkaline sulfide leaching can be suitably used as a chemical pretreatment method prior to the conventional cyanidation for antimonial refractory gold and silver ores.

Investigation of the impacts of thermal pretreatment on waste activated sludge and development of a pretreatment model.

Science.gov (United States)

Burger, Gillian; Parker, Wayne

2013-09-15

This study investigated the impacts of high pressure thermal hydrolysis (HPTH) pretreatment on the distribution of chemical oxygen demand (COD) species in waste activated sludge (WAS). In the first phase of the project, WAS from a synthetically-fed biological reactor (BR) was fed to an aerobic digester (AD). In the second phase, WAS from the BR was pretreated by HPTH at 150 °C and 3 bars for 30 min prior to being fed to the AD. A range of physical, biochemical and biological properties were regularly measured in each process stream in both phases. The COD of the BR WAS consisted of storage products (XSTO), active heterotrophs (XH) and endogenous decay products (XE). Pretreatment did not increase the extent to which the BR WAS was aerobically digested and hence it was concluded that the unbiodegradable COD fraction, i.e. XE, was unchanged by pretreatment. However, pretreatment did increase the rate of degradation as it converted 36% of XH to readily biodegradable COD (SB) and the remaining XH to slowly biodegradable COD (XB). Furthermore, XSTO was fully converted to SB by pretreatment. Although pretreatment did not change the VSS concentration in the downstream aerobic digester, it did decrease the ISS concentration by 46 ± 11%. This reduced the total mass of solids produced by the digester by 21 ± 8%. A COD-based HPTH pretreatment model was developed and calibrated. When this model was integrated into BioWin 3.1(®), it was able to accurately simulate both the steady state performance of the overall system employed in this study as well as dynamic respirometry results. Copyright © 2013 Elsevier Ltd. All rights reserved.

Influence of different pre-treatment routes on the anaerobic digestion of a filamentous algae

DEFF Research Database (Denmark)

Ehimen, Ehiazesebhor Augustine; Holm-Nielsen, Jens Bo; Poulsen, M.

2013-01-01

biomass blending (20% compared to use of a mechanical size reduction method alone. The methane yields from Rhizoclonium biomass were however observed to be considerably lower than those of other algae species from......The anaerobic digestion of outdoor cultivated Rhizoclonium biomass was investigated in this study. The influence of applying mechanical and biological pre-treatment methods prior to the biomass digestion on the overall methane yields was examined. The results show that the application of a combined...

Pretreatment techniques for biofuels and biorefineries

Energy Technology Data Exchange (ETDEWEB)

Fang, Zhen (ed.) [Chinese Academy of Sciences, Kunming, YN (China). Xishuangbanna Tropical Botonical Garden

2013-02-01

The first book focused on pretreatment techniques for biofuels contributed by the world's leading experts. Extensively covers the different types of biomass, various pretreatment approaches and methods that show the subsequent production of biofuels and chemicals. In addition to traditional pretreatment methods, novel techniques are also introduced and discussed. An accessible reference work for students, researchers, academicians and industrialists in biorefineries. This book includes 19 chapters contributed by the world's leading experts on pretreatment methods for biomass. It extensively covers the different types of biomass (e.g. molasses, sugar beet pulp, cheese whey, sugarcane residues, palm waste, vegetable oil, straws, stalks and wood), various pretreatment approaches (e.g. physical, thermal, chemical, physicochemical and biological) and methods that show the subsequent production of biofuels and chemicals such as sugars, ethanol, extracellular polysaccharides, biodiesel, gas and oil. In addition to traditional methods such as steam, hot-water, hydrothermal, diluted-acid, organosolv, ozonolysis, sulfite, milling, fungal and bacterial, microwave, ultrasonic, plasma, torrefaction, pelletization, gasification (including biogas) and liquefaction pretreatments, it also introduces and discusses novel techniques such as nano and solid catalysts, organic electrolyte solutions and ionic liquids. This book offers a review of state-of-the-art research and provides guidance for the future paths of developing pretreatment techniques of biomass for biofuels, especially in the fields of biotechnology, microbiology, chemistry, materials science and engineering. It intends to provide a systematic introduction of pretreatment techniques. It is an accessible reference work for students, researchers, academicians and industrialists in biorefineries.

Pretreatment Solution for Water Recovery Systems

Science.gov (United States)

Muirhead, Dean (Inventor)

2018-01-01

Chemical pretreatments are used to produce usable water by treating a water source with a chemical pretreatment that contains a hexavalent chromium and an acid to generate a treated water source, wherein the concentration of sulfate compounds in the acid is negligible, and wherein the treated water source remains substantially free of precipitates after the addition of the chemical pretreatment. Other methods include reducing the pH in urine to be distilled for potable water extraction by pretreating the urine before distillation with a pretreatment solution comprising one or more acid sources selected from a group consisting of phosphoric acid, hydrochloric acid, and nitric acid, wherein the urine remains substantially precipitate free after the addition of the pretreatment solution. Another method described comprises a process for reducing precipitation in urine to be processed for water extraction by mixing the urine with a pretreatment solution comprising hexavalent chromium compound and phosphoric acid.

Observations of pretreatment prostate-specific antigen doubling time in 107 patients referred for definitive radiotherapy

International Nuclear Information System (INIS)

Lee, W. Robert; Hanks, Gerald E.; Corn, Benjamin W.; Schultheiss, Timothy E.

1995-01-01

Purpose: To determine pretreatment prostate-specific antigen doubling times (PSADT) in patients referred for definitive radiotherapy. Methods and Materials: One hundred and seven patients with histologically proven nonmetastatic prostate cancer and an elevated prostate-specific antigen (PSA) who were referred for radiation therapy had three serum PSA values obtained prior to the start of definitive therapy. Prostate-specific antigen doubling times were calculated by linear regression. Results: Prostate-specific antigen values increased during the period of observation in 78 patients (73%). Forty-three patients (40%) had calculated PSADT of less than 2 years and of those patients with pretreatment serum PSA values of greater than 10 ng/mL more than 50% has calculated PSADT of less than 2 years. Conclusions: A significant minority of patients referred for radiotherapy have calculated PSADT of less than 2 years. The significance of this relatively fast growth rate is as yet undetermined, but suggests that patients referred for radiotherapy may have aggressive disease prior to treatment

Pretreatment Diffusion-Weighted MRI Can Predict the Response to Neoadjuvant Chemotherapy in Patients with Nasopharyngeal Carcinoma

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Guo-Yi Zhang

2015-01-01

Full Text Available Purpose. To explore the potential of diffusion-weighted (DW magnetic resonance imaging (MRI using apparent diffusion coefficient (ADC for predicting the response to neoadjuvant chemotherapy in nasopharyngeal carcinoma (NPC. Methods and Materials. Ninety-two consecutive patients with NPC who underwent three cycles of neoadjuvant chemotherapy were retrospectively analyzed. DW and anatomical MRI were performed before and after neoadjuvant chemotherapy prior to radiotherapy. Pretreatment ADCs and percentage increases in ADC after chemotherapy were calculated for the primary lesions and metastatic adenopathies. Receiver operating characteristic curve analysis was used to select optimal pretreatment ADCs. Results. Pretreatment mean ADCs were significantly lower for responders than for nonresponders (primary lesions, P=0.012; metastatic adenopathies, P=0.013. Mean percentage increases in ADC were higher for responders than for nonresponders (primary lesions, P=0.008; metastatic adenopathies, P<0.001. The optimal pretreatment primary lesion and metastatic adenopathy ADCs for differentiating responders from nonresponders were 0.897 × 10−3 mm2/sec and 1.031 × 10−3 mm2/sec, respectively. Conclusions. NPC patients with low pretreatment ADCs tend to respond better to neoadjuvant chemotherapy. Pretreatment ADCs could be used as a new pretreatment imaging biomarker of response to neoadjuvant chemotherapy.

Hydrolysis of Miscanthus for bioethanol production using dilute acid presoaking combined with wet explosion pre-treatment and enzymatic treatment

DEFF Research Database (Denmark)

Sørensen, Annette; Teller, Philip Johan; Hilstrøm, Troels

2008-01-01

xylose prior to wet explosion. The acid presoaking extracted 63.2% xylose and 5.2% glucose. Direct enzymatic hydrolysis of the presoaked biomass was found to give only low sugar yields of 24-26% glucose. Wet explosion is a pre-treatment method that combines wet-oxidation and steam explosion. The effect...... of wet explosion on non-presoaked and presoaked Miscanthus was investigated using both atmospheric air and hydrogen peroxide as the oxidizing agent. All wet explosion pre-treatments showed to have a disrupting effect on the lignocellulosic biomass, making the sugars accessible for enzymatic hydrolysis......Miscanthus is a high yielding bioenergy crop. In this study we used acid presoaking, wet explosion, and enzymatic hydrolysis to evaluate the combination of the different pre-treatment methods for bioethanol production with Miscanthus. Acid presoaking is primarily carried out in order to remove...

A Single Image Dehazing Method Using Average Saturation Prior

Directory of Open Access Journals (Sweden)

Zhenfei Gu

2017-01-01

Full Text Available Outdoor images captured in bad weather are prone to yield poor visibility, which is a fatal problem for most computer vision applications. The majority of existing dehazing methods rely on an atmospheric scattering model and therefore share a common limitation; that is, the model is only valid when the atmosphere is homogeneous. In this paper, we propose an improved atmospheric scattering model to overcome this inherent limitation. By adopting the proposed model, a corresponding dehazing method is also presented. In this method, we first create a haze density distribution map of a hazy image, which enables us to segment the hazy image into scenes according to the haze density similarity. Then, in order to improve the atmospheric light estimation accuracy, we define an effective weight assignment function to locate a candidate scene based on the scene segmentation results and therefore avoid most potential errors. Next, we propose a simple but powerful prior named the average saturation prior (ASP, which is a statistic of extensive high-definition outdoor images. Using this prior combined with the improved atmospheric scattering model, we can directly estimate the scene atmospheric scattering coefficient and restore the scene albedo. The experimental results verify that our model is physically valid, and the proposed method outperforms several state-of-the-art single image dehazing methods in terms of both robustness and effectiveness.

Production of brown algae pyrolysis oils for liquid biofuels depending on the chemical pretreatment methods

International Nuclear Information System (INIS)

Choi, Joonhyuk; Choi, Jae-Wook; Suh, Dong Jin; Ha, Jeong-Myeong; Hwang, Ji Won; Jung, Hyun Wook; Lee, Kwan-Young; Woo, Hee-Chul

2014-01-01

Highlights: • Pyrolysis of Saccharina japonica, brown algae to produce hydrocarbons. • Sulfuric acid pretreatment of macroalgae to remove inorganic elements. • CaCl 2 treatment of macroalgae to remove valuable fucoidan. • Sulfuric acid pretreatment suppressed the formation of large biochar chunks. • The pretreatment methods allowed the continuous operation of pyrolysis. - Abstract: Based on observations of rapidly growing biochar in fluidization beds, kelp (Saccharina japonica), a species of brown algae, was pretreated for the efficient operation of pyrolysis processes to produce pyrolysis oils. The removal of catalytically active inorganic minerals and the softening of polymeric seaweed structures were performed by means of chemical treatments, including a CaCl 2 treatment to isolate valuable and sticky fucoidan and a sulfuric acid treatment to remove catalytically active minerals. The sulfuric acid pretreatment significantly reduced the inorganic elements but did not significantly affect the properties of the pyrolysis oil compared to the non-treated kelp pyrolysis oil. Whereas the non-treated kelp produced significantly large chunks of biochar, which hindered the continuous operation of pyrolysis, the kelp treated with sulfuric acid did not produce aggregated large particles of biochar, thereby offering a means of developing reliable continuous pyrolysis processes

Improved sugar yields from biomass sorghum feedstocks: comparing low-lignin mutants and pretreatment chemistries.

Science.gov (United States)

Godin, Bruno; Nagle, Nick; Sattler, Scott; Agneessens, Richard; Delcarte, Jérôme; Wolfrum, Edward

2016-01-01

For biofuel production processes to be economically efficient, it is essential to maximize the production of monomeric carbohydrates from the structural carbohydrates of feedstocks. One strategy for maximizing carbohydrate production is to identify less recalcitrant feedstock cultivars by performing some type of experimental screening on a large and diverse set of candidate materials, or by identifying genetic modifications (random or directed mutations or transgenic plants) that provide decreased recalcitrance. Economic efficiency can also be increased using additional pretreatment processes such as deacetylation, which uses dilute NaOH to remove the acetyl groups of hemicellulose prior to dilute acid pretreatment. In this work, we used a laboratory-scale screening tool that mimics relevant thermochemical pretreatment conditions to compare the total sugar yield of three near-isogenic brown midrib ( bmr ) mutant lines and the wild-type (WT) sorghum cultivar. We then compared results obtained from the laboratory-scale screening pretreatment assay to a large-scale pretreatment system. After pretreatment and enzymatic hydrolysis, the bmr mutants had higher total sugar yields than the WT sorghum cultivar. Increased pretreatment temperatures increased reactivity for all sorghum samples reducing the differences observed at lower reaction temperatures. Deacetylation prior to dilute acid pretreatment increased the total sugar yield for all four sorghum samples, and reduced the differences in total sugar yields among them, but solubilized a sizable fraction of the non-structural carbohydrates. The general trends of increased total sugar yield in the bmr mutant compared to the WT seen at the laboratory scale were observed at the large-scale system. However, in the larger reactor system, the measured total sugar yields were lower and the difference in total sugar yield between the WT and bmr sorghum was larger. Sorghum bmr mutants, which have a reduced lignin content showed

PROJECT W-551 INTERIM PRETREATMENT SYSTEM PRECONCEPTUAL CANDIDATE TECHNOLOGY DESCRIPTIONS

Energy Technology Data Exchange (ETDEWEB)

MAY TH

2008-08-12

The Office of River Protection (ORP) has authorized a study to recommend and select options for interim pretreatment of tank waste and support Waste Treatment Plant (WTP) low activity waste (LAW) operations prior to startup of all the WTP facilities. The Interim Pretreatment System (IPS) is to be a moderately sized system which separates entrained solids and 137Cs from tank waste for an interim time period while WTP high level waste vitrification and pretreatment facilities are completed. This study's objective is to prepare pre-conceptual technology descriptions that expand the technical detail for selected solid and cesium separation technologies. This revision includes information on additional feed tanks.

Microwave and thermal pretreatment as methods for increasing the biogas potential of secondary sludge from municipal wastewater treatment plants

DEFF Research Database (Denmark)

Kuglarz, Mariusz; Karakashev, Dimitar Borisov; Angelidaki, Irini

2013-01-01

In the present study, the sludge was pretreated with microwave irradiation and low-temperature thermal method, both conducted under the same temperature range (30–100°C). Microwave pretreatment was found to be superior over the thermal treatment with respect to sludge solubilization and biogas pr...... experiments indicated that pre-treated sludge (microwave irradiation: 900W, temperature: 60–70°C) gave 35% more methane, compared to untreated sludge. Moreover, the results of this study clearly demonstrated that microwave pretreated sludge showed better degree of sanitation....

Powerful peracetic acid-ionic liquid pretreatment process for the efficient chemical hydrolysis of lignocellulosic biomass.

Science.gov (United States)

Uju; Goto, Masahiro; Kamiya, Noriho

2016-08-01

The aim of this work was to design a new method for the efficient saccharification of lignocellulosic biomass (LB) using a combination of peracetic acid (PAA) pretreatment with ionic liquid (IL)-HCl hydrolysis. The pretreatment of LBs with PAA disrupted the lignin fractions, enhanced the dissolution of LB and led to a significant increase in the initial rate of the IL-HCl hydrolysis. The pretreatment of Bagasse with PAA prior to its 1-buthyl-3-methylimidazolium chloride ([Bmim][Cl])-HCl hydrolysis, led to an improvement in the cellulose conversion from 20% to 70% in 1.5h. Interestingly, the 1-buthyl-3-methylpyridium chloride ([Bmpy][Cl])-HCl hydrolysis of Bagasse gave a cellulose conversion greater than 80%, with or without the PAA pretreatment. For LB derived from seaweed waste, the cellulose conversion reached 98% in 1h. The strong hydrolysis power of [Bmpy][Cl] was attributed to its ability to transform cellulose I to II, and lowering the degree of polymerization of cellulose. Copyright © 2016 Elsevier Ltd. All rights reserved.

Combined electrical-alkali pretreatment to increase the anaerobic hydrolysis rate of waste activated sludge during anaerobic digestion

International Nuclear Information System (INIS)

Zhen, Guangyin; Lu, Xueqin; Li, Yu-You; Zhao, Youcai

2014-01-01

Highlights: • Combined electrical-alkali pretreatment for improving sludge anaerobic digestion was proposed. • Combined process enhanced the cell lysis, biopolymers releases, and thus sludge disintegration. • Increased solubilization of sludge increased the anaerobic hydrolysis rate. • Increased solubilization does not always induce an improved anaerobic digestion efficiency. - Abstract: Pretreatment can be used prior to anaerobic digestion to improve the efficiency of waste activated sludge (WAS) digestion. In this study, electrolysis and a commonly used pretreatment method of alkaline (NaOH) solubilization were integrated as a pretreatment method for promoting WAS anaerobic digestion. Pretreatment effectiveness of combined process were investigated in terms of disintegration degree (DD SCOD ), suspended solids (TSS and VSS) removals, the releases of protein (PN) and polysaccharide (PS), and subsequent anaerobic digestion as well as dewaterability after digestion. Electrolysis was able to crack the microbial cells trapped in sludge gels and release the biopolymers (PN and PS) due to the cooperation of alkaline solubilization, enhancing the sludge floc disintegration/solubilization, which was confirmed by scanning electron microscopy (SEM) analysis. Biochemical methane potential (BMP) assays showed the highest methane yield was achieved with 5 V plus pH 9.2 pretreatment with up to 20.3% improvement over the non-pretreated sludge after 42 days of mesophilic operation. In contrast, no discernible improvements on anaerobic degradability were observed for the rest of pretreated sludges, probably due to the overmuch leakage of refractory soluble organics, partial chemical mineralization of solubilized compounds and sodium inhibition. The statistical analysis further indicated that increased solubilization induced by electrical-alkali pretreatment increased the first-order anaerobic hydrolysis rate (k hyd ), but had no, or very slight enhancement on WAS ultimate

A 2-week pretreatment with 13-cis-retinoic acid + interferon-α-2a prior to definitive radiation improves tumor tissue oxygenation in cervical cancers

International Nuclear Information System (INIS)

Dunst, J.; Haensgen, G.; Becker, A.; Krause, U.; Fuechsel, G.; Koehler, U.

1998-01-01

Background: We have evaluated the tumor tissue pO 2 in cervical cancers in patients treated with 13-cis-retinoic acid and interferon-α-2a prior to and during radiotherapy. Patients and methods: From June 1995 through April 1997, 22 patients with squamous cell carcinoma FIGO IIB/III of the cervix who were scheduled for definitive radiotherapy with curative intent received additional treatment with 13-cis-retinoic acid (cRA, isotretinoin) plus interferon-α-2a (IFN-α-2a) as part of a phase-II protocol. cRA/IFN-α-2a started 14 days prior to radiotherapy (1 mg per kilogramme body weight cRA orally daily plus 6x10 6 IU IFN-α-2a subcutaneously daily). After this indicution period, standard radiotherapy was administered (external irradiation with 50.4 Gy in 28 fractions of 1.8 Gy plus HDR-brachytherapy). During radiotherapy, cRA/IFN-α-2a-treatment was continued with 50% of the daily doses. Tumor tissue pO 2 -measurements were performed prior to and after the cRA/IFN-induction period as well as at 20 Gy and at the end of radiotherapy with an Eppendorf-pO 2 -histograph. Results: In 11 out of the 22 patients, pO 2 -measurements were performed prior to the cRA/IFN-induction therapy. The median pO 2 of these untreated tumors was 17.7±16.3 mm Hg. The relative frequency of hypoxic readings with pO 2 -values below 5 mm Hg ranged from 0% to 60.6% (mean 24.3±21.0%). After the 2-week induction period with cRA/IFN, the median pO 2 had increased from 17.7pm16.3 mm Hg to 27.6±19.1 mm Hg (not significant). In all 5 patients with hypoxic tumors prior to cRA/IFN (median pO 2 of 10 mm Hg or less), the median pO 2 was above 20 mm Hg after the 2-week cRA/IFN-induction. In this subgroup of hypoxic tumors, the median pO 2 increased from 6.3±2.7 mm Hg to 27.0±5.6 mm Hg (p=0.004, t-test for paired samples). The frequency of hypoxic readings (pO 2 -values 2 below 10 mm Hg prior to treatment), 4/5 achieved complete remission. Conclusions: Pretreatment with cRA/IFN improves oxygenation of

Use of high-intensity sonication for pre-treatment of biological tissues prior to multielemental analysis by total reflection X-ray fluorescence spectrometry

International Nuclear Information System (INIS)

De La Calle, Inmaculada; Costas, Marta; Cabaleiro, Noelia; Lavilla, Isela; Bendicho, Carlos

2012-01-01

In this work, two ultrasound-based procedures are developed for sample preparation prior to determination of P, K, Ca, Cr, Mn, Fe, Ni, Cu, Zn, As, Se and Sr in biological tissues by total reflection X-ray fluorescence spectrometry. Ultrasound-assisted extraction by means of a cup-horn sonoreactor and ultrasonic-probe slurry sampling were compared with a well-established procedure such as magnetic agitation slurry sampling. For that purpose, seven certified reference materials and different real samples of animal tissue were used. Similar accuracy and precision is obtained with the three sample preparation approaches tried. Limits of detection were dependent on both the sample matrix and the sample pre-treatment used, best values being achieved with ultrasound-assisted extraction. Advantages of ultrasound-assisted extraction include reduced sample handling, decreased contamination risks (neither addition of surfactants nor use of foreign objects inside the extraction vial), simpler background (no solid particles onto the sample carrier) and improved recovery for some elements such as P. A mixture of 10% v/v HNO 3 + 20–40% v/v HCl was suitable for extraction from biological tissues. - Highlights: ► We implement high-intensity sonication for pre-treatment of biological tissues. ► Multielemental analysis is performed by total reflection X-ray spectrometry. ► Ultrasound-based procedures are developed and compared to conventional slurry preparation. ► Features such as background, recovery and sample handling are favored by using ultrasonic extraction.

Thermal pre-treatment of primary and secondary sludge at 70ºC prior to anaerobic digestion

DEFF Research Database (Denmark)

Skiadas, Ioannis V.; Gavala, H.N.; Lu, Jingquan

2005-01-01

. The present study investigates the effect of the pre-treatment at 70 degrees C on thermophilic (55 degrees C) anaerobic digestion of primary and secondary sludge in continuously operated digesters. Thermal pre-treatment of primary and secondary sludge at 70 degrees C enhanced the removal of organic matter...... and the methane production during the subsequent anaerobic digestion step at 55 degrees C. It also greatly contributed to the destruction of pathogens present in primary sludge. Finally it results in enhanced microbial activities of the subsequent anaerobic step suggesting that the same efficiencies in organic...... matter removal and methane recovery could be obtained at lower HRTs....

Pretreatment of the macroalgae Chaetomorpha linum for the production of bioethanol - Comparison of five pretreatment technologies

DEFF Research Database (Denmark)

Schultz-Jensen, Nadja; Thygesen, Anders; Thomsen, Sune Tjalfe

2013-01-01

-assisted pretreatment (PAP) and ball milling (BM), to determine effects of the pretreatment methods on the conversion of C. linum into ethanol by simultaneous saccharification and fermentation (SSF). WO and BM showed the highest ethanol yield of 44. g ethanol/100. g glucan, which was close to the theoretical ethanol......A qualified estimate for pretreatment of the macroalgae Chaetomorpha linum for ethanol production was given, based on the experience of pretreatment of land-based biomass. C. linum was subjected to hydrothermal pretreatment (HTT), wet oxidation (WO), steam explosion (STEX), plasma...... yield of 57. g ethanol/100. g glucan. A 64% higher ethanol yield, based on raw material, was reached after pretreatment with WO and BM compared with unpretreated C. linum, however 50% of the biomass was lost during WO. Results indicated that the right combination of pretreatment and marine macroalgae...

Adsorptive detoxification of fermentation inhibitors in acid pretreated liquor using functionalized polymer designed by molecular simulation.

Science.gov (United States)

Devendra, Leena P; Pandey, Ashok

2017-11-01

Acid pretreatment is the most common method employed in the lignocellulosic biorefinery leading to the separation of pentose and hexose sugar. The liquor obtained after pretreatment (acid pretreatment liquor or APL) needs to be detoxified prior to fermentation. The aim of this study was to design functional groups on a polymer matrix which are selective in their interaction to inhibitors with little or no specificity to sugars. Molecular modeling was used as a tool to design a suitable adsorbent for selective adsorption of inhibitors from a complex mixture of APL. Phenyl glycine-p-sulfonic acid loaded on chloromethylated polystyrene polymer was designed as an adsorbent for selective interaction with inhibitors. Experimental verification of the selectivity was successfully achieved. The current study provides insights on the adsorptive separation processes at the molecular level by design of specific adsorbent which can be tailor made for the better selectivity of the desired component.

Different extraction pretreatments significantly change the flavonoid contents of Scutellaria baicalensis

Science.gov (United States)

Yu, Chunhao; Qu, Fengyun; Mao, Yanyong; Li, Dong; Zhen, Zhong; Nass, Rachael; Calway, Tyler; Wang, Yunwei; Yuan, Chun-Su; Wang, Chong-Zhi

2014-01-01

Context Scutellaria baicalensis is one of the most commonly used medicinal herbs, especially in traditional Chinese medicine. However, compared to many pharmacological studies of this botanical, much less attention has been paid to the quality control of the herb’s pretreatment prior to extract preparation, an issue that may affect therapeutic outcomes. Objective The current study was designed to evaluate whether different pretreatment conditions change the contents of its four major flavonoids in the herb, i.e., two glycosides (baicalin and wogonoside) and two aglycons (baicalein and wogonin). Materials and methods An HPLC assay was used to quantify the contents of these four flavonoids. The composition changes of four flavonoids by different pretreatment conditions including solvent, treatment time, temperature, pH value, and herb/solvent ratio were evaluated. Results After selection of the first order time-curve kinetics, our data showed that at 50°C, 1:5 herb/water (in w/v) ratio and pH 6.67 yielded an optimal conversion rate from flavonoid glycosides to their aglycons. In this optimized condition, the contents of baicalin and wogonoside were decreased to 1/70 and 1/13, while baicalein and wogonin were increased 3.5 and 3.1 folds, respectively, compared to untreated herb. Discussion and conclusion The markedly variable conversion rates by different pretreatment conditions complicated the quality control of this herb, mainly due to the high amount of endogenous enzymes of S. baicalensis. Optimal pretreatment conditions obtained from this study could be used obtain the highest level of desired constituents to achieve better pharmacological effects. PMID:23738852

Pretreated high lipid serum method and its significance before determine INS C-P by RIA

International Nuclear Information System (INIS)

Wan Guangxia; Zhu Liqiang; Wu Yufang

2004-01-01

The method of predigest high lipid serum before determine INS and C-P for elimination of the high lipid in serum was studied. The specimen was divided into two groups, one was directly tested, the other was pretreated, then determined(including INS and QC of serum, normal and high lipid serum, pretreating serum). The results were compared by examine and analysed correlatively. Results show that INS and C-P of the specimens pretreated by PEG, were no statistic difference in relation to direct tested (P>0.05) and those were close correlatively (P<0.001) in normal. The results of high lipid serum after the specimens were predigest by PEG were marked by decrease in relation to direct tested (P<0.001). High lipid and INS antibody were eliminated by PEG so that was increased the results nicety. (authors)

Diffusion-weighted magnetic resonance imaging for pretreatment prediction and monitoring of treatment response of patients with locally advanced breast cancer undergoing neoadjuvant chemotherapy

International Nuclear Information System (INIS)

Nilsen, Line; Olsen, Dag Rune; Seierstad, Therese; Fangberget, Anne; Geier, Oliver

2010-01-01

Background. For patients with locally advanced breast cancer (LABC) undergoing neoadjuvant chemotherapy (NACT), the European Guidelines for Breast Imaging recommends magnetic resonance imaging (MRI) to be performed before start of NACT, when half of the NACT has been administered and prior to surgery. This is the first study addressing the value of flow-insensitive apparent diffusion coefficients (ADCs) obtained from diffusion-weighted (DW) MRI at the recommended time points for pretreatment prediction and monitoring of treatment response. Materials and methods. Twenty-five LABC patients were included in this prospective study. DW MRI was performed using single-shot spin-echo echo-planar imaging with b-values of 100, 250 and 800 s/mm 2 prior to NACT, after four cycles of NACT and at the conclusion of therapy using a 1.5 T MR scanner. ADC in the breast tumor was calculated from each assessment. The strength of correlation between pretreatment ADC, ADC changes and tumor volume changes were examined using Spearman's rho correlation test. Results. Mean pretreatment ADC was 1.11 ± 0.21 x 10 -3 mm 2 /s. After 4 cycles of NACT, ADC was significantly increased (1.39 ± 0.36 x 10 -3 mm 2 /s; p=0.018). There was no correlation between individual pretreatment breast tumor ADC and MR response measured after four cycles of NACT (p=0.816) or prior to surgery (p=0.620). Conclusion. Pretreatment tumor ADC does not predict treatment response for patients with LABC undergoing NACT. Furthermore, ADC increase observed mid-way in the course of NACT does not correlate with tumor volume changes.

High-Dose Statin Pretreatment Decreases Periprocedural Myocardial Infarction and Cardiovascular Events in Patients Undergoing Elective Percutaneous Coronary Intervention: A Meta-Analysis of Twenty-Four Randomized Controlled Trials

Science.gov (United States)

Wang, Le; Peng, Pingan; Zhang, Ou; Xu, Xiaohan; Yang, Shiwei; Zhao, Yingxin; Zhou, Yujie

2014-01-01

Background Evidence suggests that high-dose statin pretreatment may reduce the risk of periprocedural myocardial infarction (PMI) and major adverse cardiac events (MACE) for certain patients; however, previous analyses have not considered patients with a history of statin maintenance treatment. In this meta-analysis of randomized controlled trials (RCTs), we reevaluated the efficacy of short-term high-dose statin pretreatment to prevent PMI and MACE in an expanded set of patients undergoing elective percutaneous coronary intervention. Methods We searched the PubMed/Medline database for RCTs that compared high-dose statin pretreatment with no statin or low-dose statin pretreatment as a prevention of PMI and MACE. We evaluated the incidence of PMI and MACE, including death, spontaneous myocardial infarction, and target vessel revascularization at the longest follow-up for each study for subgroups stratified by disease classification and prior low-dose statin treatment. Results Twenty-four RCTs with a total of 5,526 patients were identified. High-dose statin pretreatment was associated with 59% relative reduction in PMI (odds ratio [OR]: 0.41; 95% confidence interval [CI]: 0.34–0.49; Pstatin pretreatment on MACE was significant for statin-naive patients (OR: 0.69; 95% CI: 0.50–0.95; P = 0.02) and prior low dose statin-treated patients (OR: 0.28; 95% CI: 0.12–0.65; P = 0.003); and for patients with acute coronary syndrome (OR: 0.52; 95% CI: 0.34–0.79; P = 0.003), but not for patients with stable angina (OR: 0.71; 95% CI 0.45–1.10; P = 0.12). Long-term effects on survival were less obvious. Conclusions High-dose statin pretreatment can result in a significant reduction in PMI and MACE for patients undergoing elective PCI. The positive effect of high-dose statin pretreatment on PMI and MACE is significant for statin-naïve patients and patients with prior treatment. The positive effect of high-dose statin pretreatment on MACE is significant for

Remediation of DDT-contaminated water and soil by using pretreated iron byproducts from the automotive industry.

Science.gov (United States)

Satapanajaru, Tunlawit; Anurakpongsatorn, Patana; Pengthamkeerati, Patthra

2006-01-01

The objective of this study was to quantify the effectiveness of different pretreated iron byproducts from the automotive industry to degrade DDT [(1,1,1-trichloro-2,2-bis(4-chlorophenyl) ethane] in aqueous solutions and soil slurry. Iron byproducts from automotive manufacturing were pretreated by three different methods (heating, solvent and 0.5N HCl acid washing) prior to experimentation. All pretreated irons were used at 5% (wt v-1) to treat 0.014 mM (5 mgL-1) of DDT in aqueous solution. Among the pretreated irons, acid pretreated iron results in the fastest destruction rates, with a pseudo first-order degradation rate of 0.364 d-1. By lowering the pH of the DDT aqueous solution from 9 to 3, destruction kinetic rates increase more than 20%. In addition, when DDT-contaminated soil slurry (3.54 mg kg-1) was incubated with 5% (wt v-1) acid-pretreated iron, more than 90% destruction of DDT was observed within 8 weeks. Moreover, DDT destruction kinetics were enhanced when Fe(II), Fe(III) or Al(III) sulfate salts were added to the soil slurry, with the following order of destruction kinetics: Al(III) sulfate > Fe(III) sulfate > Fe(II) sulfate. These results provide proof-of concept that inexpensive iron byproducts of the automotive industry can be used to remediate DDT-contaminated water and soil.

Optimizing Phosphoric Acid plus Hydrogen Peroxide (PHP) Pretreatment on Wheat Straw by Response Surface Method for Enzymatic Saccharification.

Science.gov (United States)

Qiu, Jingwen; Wang, Qing; Shen, Fei; Yang, Gang; Zhang, Yanzong; Deng, Shihuai; Zhang, Jing; Zeng, Yongmei; Song, Chun

2017-03-01

Wheat straw was pretreated by phosphoric acid plus hydrogen peroxide (PHP), in which temperature, time, and H 3 PO 4 proportion for pretreatment were investigated by using response surface method. Results indicated that hemicellulose and lignin removal positively responded to the increase of pretreatment temperature, H 3 PO 4 proportion, and time. H 3 PO 4 proportion was the most important variable to control cellulose recovery, followed by pretreatment temperature and time. Moreover, these three variables all negatively related to cellulose recovery. Increasing H 3 PO 4 proportion can improve enzymatic hydrolysis; however, reduction on cellulose recovery results in decrease of glucose yield. Extra high temperature or long time for pretreatment was not beneficial to enzymatic hydrolysis and glucose yield. Based on the criterion for minimizing H 3 PO 4 usage and maximizing glucose yield, the optimized pretreatment conditions was 40 °C, 2.0 h, and H 3 PO 4 proportion of 70.2 % (H 2 O 2 proportion of 5.2 %), by which glucose yielded 299 mg/g wheat straw (946.2 mg/g cellulose) after 72-h enzymatic hydrolysis.

Synergism between ultrasonic pretreatment and white rot fungal enzymes on biodegradation of wheat chaff.

Science.gov (United States)

Sabarez, Henry; Oliver, Christine Maree; Mawson, Raymond; Dumsday, Geoff; Singh, Tanoj; Bitto, Natalie; McSweeney, Chris; Augustin, Mary Ann

2014-11-01

Lignocellulosic biomass samples (wheat chaff) were pretreated by ultrasound (US) (40kHz/0.5Wcm(-2)/10min and 400kHz/0.5Wcm(-2)/10min applied sequentially) prior to digestion by enzyme extracts obtained from fermentation of the biomass with white rot fungi (Phanerochaete chrysosporium or Trametes sp.). The accessibility of the cellulosic components in wheat chaff was increased, as demonstrated by the increased concentration of sugars produced by exposure to the ultrasound treatment prior to enzyme addition. Pretreatment with ultrasound increased the concentration of lignin degradation products (guaiacol and syringol) obtained from wheat chaff after enzyme addition. In vitro digestibility of wheat chaff was also enhanced by the ultrasonics pretreatment in combination with treatment with enzyme extracts. Degradation was enhanced with the use of a mixture of the enzyme extracts compared to that for a single enzyme extract. Copyright © 2014. Published by Elsevier B.V.

Mephedrone interactions with cocaine: prior exposure to the 'bath salt' constituent enhances cocaine-induced locomotor activation in rats.

Science.gov (United States)

Gregg, Ryan A; Tallarida, Christopher S; Reitz, Allen B; Rawls, Scott M

2013-12-01

Concurrent use of mephedrone (4-methylmethcathinone; MEPH) and established drugs of abuse is now commonplace, but knowledge about interactions between these drugs is sparse. The present study was designed to test the hypothesis that prior MEPH exposure enhances the locomotor-stimulant effects of cocaine and methamphetamine (METH). For cocaine experiments, rats pretreated with saline, cocaine (15 mg/kg), or MEPH (15 mg/kg) for 5 days were injected with cocaine after 10 days of drug absence. For METH experiments, rats pretreated with saline, METH (2 mg/kg), or MEPH (15 mg/kg) were injected with METH after 10 days of drug absence. Cocaine challenge produced greater locomotor activity after pretreatment with cocaine or MEPH than after pretreatment with saline. METH challenge produced greater locomotor activity after METH pretreatment than after saline pretreatment; however, locomotor activity in rats pretreated with MEPH or saline and then challenged with METH was not significantly different. The locomotor response to MEPH (15 mg/kg) was not significantly affected by pretreatment with cocaine (15 mg/kg) or METH (0.5, 2 mg/kg). The present demonstration that cocaine-induced locomotor activation is enhanced by prior MEPH exposure suggests that MEPH cross-sensitizes to cocaine and increases cocaine efficacy. Interestingly, MEPH cross-sensitization was not bidirectional and did not extend to METH, suggesting that the phenomenon is sensitive to specific psychostimulants.

Use of principal components analysis (PCA) on estuarine sediment datasets: The effect of data pre-treatment

International Nuclear Information System (INIS)

Reid, M.K.; Spencer, K.L.

2009-01-01

Principal components analysis (PCA) is a multivariate statistical technique capable of discerning patterns in large environmental datasets. Although widely used, there is disparity in the literature with respect to data pre-treatment prior to PCA. This research examines the influence of commonly reported data pre-treatment methods on PCA outputs, and hence data interpretation, using a typical environmental dataset comprising sediment geochemical data from an estuary in SE England. This study demonstrated that applying the routinely used log (x + 1) transformation skewed the data and masked important trends. Removing outlying samples and correcting for the influence of grain size had the most significant effect on PCA outputs and data interpretation. Reducing the influence of grain size using granulometric normalisation meant that other factors affecting metal variability, including mineralogy, anthropogenic sources and distance along the salinity transect could be identified and interpreted more clearly. - Data pre-treatment can have a significant influence on the outcome of PCA.

Conditional maximum-entropy method for selecting prior distributions in Bayesian statistics

Science.gov (United States)

Abe, Sumiyoshi

2014-11-01

The conditional maximum-entropy method (abbreviated here as C-MaxEnt) is formulated for selecting prior probability distributions in Bayesian statistics for parameter estimation. This method is inspired by a statistical-mechanical approach to systems governed by dynamics with largely separated time scales and is based on three key concepts: conjugate pairs of variables, dimensionless integration measures with coarse-graining factors and partial maximization of the joint entropy. The method enables one to calculate a prior purely from a likelihood in a simple way. It is shown, in particular, how it not only yields Jeffreys's rules but also reveals new structures hidden behind them.

PROJECT W-551 DETERMINATION DATA FOR EARLY LAW INTERIM PRETREATMENT SYSTEM SELECTION

Energy Technology Data Exchange (ETDEWEB)

TEDESCHI AR

2008-08-11

This report provides the detailed assessment forms and data for selection of the solids separation and cesium separation technology for project W-551, Interim Pretreatment System. This project will provide early pretreated low activity waste feed to the Waste Treatment Plant to allow Waste Treatment Plan Low Activity Waste facility operation prior to construction completion of the Pretreatment and High Level Waste facilities. The candidate solids separations technologies are rotary microfiltration and crossflow filtration, and the candidate cesium separation technologies are fractional crystallization, caustic-side solvent extraction, and ion-exchange using spherical resorcinol-formaldehyde resin. This data was used to prepare a cross-cutting technology summary, reported in RPP-RPT-37740.

Thermal pre-treatment of primary and secondary sludge at 70 °C prior to anaerobic digestion

DEFF Research Database (Denmark)

Skiadas, Ioannis; Gavala, Hariklia N.; Lu, J.

2005-01-01

In general, mesophilic anaerobic digestion of sewage sludge is more widely used compared tothermophilic digestion, mainly because of the lower energy requirements and higher stability of the process. However, the thermophilic anaerobic digestion process is usually characterised by accelerated...... studyinvestigates the effect of the pre-treatment at 70 °C on thermophilic (55 °C) anaerobic digestion of primaryand secondary sludge in continuously operated digesters. Thermal pre-treatment of primary and secondarysludge at 70 °C enhanced the removal of organic matter and the methane production during...... the subsequentanaerobic digestion step at 55 °C. It also greatly contributed to the destruction of pathogens present inprimary sludge. Finally it results in enhanced microbial activities of the subsequent anaerobic stepsuggesting that the same efficiencies in organic matter removal and methane recovery could be obtained...

A review on biomass classification and composition, cofiring issues and pretreatment methods

Energy Technology Data Exchange (ETDEWEB)

Jaya Shankar Tumuluru; Shahab Sokhansanj; Christopher T. Wright; Richard D. Boardman

2011-08-01

Presently around the globe there is a significant interest in using biomass for power generation as power generation from coal continues to raise environmental concerns. Biomass alone can be used for generation of power which can bring lot of environmental benefits. However the constraints of using biomass alone can include high investments costs for biomass feed systems and also uncertainty in the security of the feedstock supply due to seasonal variations and in most of the countries biomass is dispersed and the infrastructure for biomass supply is not well established. Alternatively cofiring biomass along with coal offer advantages like (a) reducing the issues related to biomass quality and buffers the system when there is insufficient feedstock quantity and (b) costs of adapting the existing coal power plants will be lower than building new systems dedicated only to biomass. However with the above said advantages there exists some technical constrains including low heating and energy density values, low bulk density, lower grindability index, higher moisture and ash content to successfully cofire biomass with coal. In order to successfully cofire biomass with coal, biomass feedstock specifications need to be established to direct pretreatment options that may include increasing the energy density, bulk density, stability during storage and grindability. Impacts on particle transport systems, flame stability, pollutant formation and boiler tube fouling/corrosion must also be minimized by setting feedstock specifications including composition and blend ratios if necessary. Some of these limitations can be overcome by using pretreatment methods. This paper discusses the impact of feedstock pretreatment methods like sizing, baling, pelletizing, briquetting, washing/leaching, torrefaction, torrefaction and pelletization and steam explosion in attainment of optimum feedstock characteristics to successfully cofire biomass with coal.

Methods for producing and using densified biomass products containing pretreated biomass fibers

Science.gov (United States)

Dale, Bruce E.; Ritchie, Bryan; Marshall, Derek

2015-05-26

A process is provided comprising subjecting a quantity of plant biomass fibers to a pretreatment to cause at least a portion of lignin contained within each fiber to move to an outer surface of said fiber, wherein a quantity of pretreated tacky plant biomass fibers is produced; and densifying the quantity of pretreated tacky plant biomass fibers to produce one or more densified biomass particulates, wherein said biomass fibers are densified without using added binder.

PRETREATMENT TECHNOLOGIES IN BIOETHANOL PRODUCTION FROM LIGNOCELLULOSIC BIOMASS

Directory of Open Access Journals (Sweden)

Vanja Janušić

2008-07-01

Full Text Available Bioethanol is today most commonly produced from corn grain and sugar cane. It is expected that there will be limits to the supply of these raw materials in the near future. Therefore, lignocellulosic biomass, namely agricultural and forest waste, is seen as an attractive feedstock for future supplies of ethanol. Lignocellulosic biomass consists of lignin, hemicellulose and cellulose. Indeed, complexicity of the lignocellulosic biomass structure causes a pretreatment to be applied prior to cellulose and hemicellulose hydrolysis into fermentable sugars. Pretreatment technologies can be physical (mechanical comminution, pyrolysis, physico-chemical (steam explosion, ammonia fiber explosion, CO2 explosion, chemical (ozonolysis, acid hydrolysis, alkaline hydrolysis, oxidative delignification, organosolvent process and biological ones.

Tailoring degradation of AZ31 alloy by surface pre-treatment and electrospun PCL fibrous coating

Energy Technology Data Exchange (ETDEWEB)

Hanas, T. [Medical Materials Laboratory, Indian Institute of Technology Madras, Chennai 600036 (India); School of Nano Science and Technology, National Institute of Technology Calicut, Calicut, Kerala 673601 (India); Sampath Kumar, T.S., E-mail: tssk@iitm.ac.in [Medical Materials Laboratory, Indian Institute of Technology Madras, Chennai 600036 (India); Perumal, Govindaraj; Doble, Mukesh [Department of Biotechnology - Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai 600036 (India)

2016-08-01

AZ31 magnesium alloy was coated with polycaprolactone (PCL) nano-fibrous layer using electrospinning technique so as to control degradation in physiological environment. Before coating, the alloy was treated with HNO{sub 3} to have good adhesion between the coating and substrate. To elucidate the role of pre-treatment and coating, samples only with PCL coating as well as HNO{sub 3} treatment only were prepared for comparison. Best coating adhesion of 4B grade by ASTM D3359–09 tape test was observed for pre-treated samples. The effect of coating on in vitro degradation and biomineralization was studied using supersaturated simulated body fluid (SBF 5 ×). The weight loss and corrosion results obtained by immersion test showed that the combination of HNO{sub 3} pre-treatment and PCL coating is very effective in controlling the degradation rate and improving bioactivity. Cytotoxicity studies using L6 cells showed that PCL coated sample has better cell adhesion and proliferation compared to uncoated samples. Nano-fibrous PCL coating combined with prior acid treatment seems to be a promising method to tailor degradation rate with enhanced bioactivity of Mg alloys. - Highlights: • PCL electrospun coating on HNO{sub 3} pre-treated AZ31 alloy controls biodegradation. • Acid pre-treatment stabilizes the substrate - coating interface. • Electrospun porous coating improves biomineralization. • Coating similar to extracellular matrix enhances cell adhesion.

Enhancing the enzymatic hydrolysis of corn stover by an integrated wet-milling and alkali pretreatment.

Science.gov (United States)

He, Xun; Miao, Yelian; Jiang, Xuejian; Xu, Zidong; Ouyang, Pingkai

2010-04-01

An integrated wet-milling and alkali pretreatment was applied to corn stover prior to enzymatic hydrolysis. The effects of NaOH concentration in the pretreatment on crystalline structure, chemical composition, and reducing-sugar yield of corn stover were investigated, and the mechanism of increasing reducing-sugar yield by the pretreatment was discussed. The experimental results showed that the crystalline structure of corn stover was disrupted, and lignin was removed, while cellulose and hemicellulose were retained in corn stover by the pretreatment with 1% NaOH in 1 h. The reducing-sugar yield from the pretreated corn stovers increased from 20.2% to 46.7% when the NaOH concentration increased from 0% to 1%. The 1% NaOH pretreated corn stover had a holocellulose conversion of 55.1%. The increase in reducing-sugar yield was related to the crystalline structure disruption and delignification of corn stover. It was clarified that the pretreatment significantly enhanced the conversion of cellulose and hemicellulose in the corn stover to sugars.

Comparison of ultrasonic and CO₂laser pretreatment methods on enzyme digestibility of corn stover.

Science.gov (United States)

Tian, Shuang-Qi; Wang, Zhen-Yu; Fan, Zi-Luan; Zuo, Li-Li

2012-01-01

To decrease the cost of bioethanol production, biomass recalcitrance needs to be overcome so that the conversion of biomass to bioethanol becomes more efficient. CO(2) laser irradiation can disrupt the lignocellulosic physical structure and reduce the average size of fiber. Analyses with Fourier transform infrared spectroscopy, specific surface area, and the microstructure of corn stover were used to elucidate the enhancement mechanism of the pretreatment process by CO(2) laser irradiation. The present work demonstrated that the CO(2) laser had potential to enhance the bioconversion efficiency of lignocellulosic waste to renewable bioethanol. The saccharification rate of the CO(2) laser pretreatment was significantly higher than ultrasonic pretreatment, and reached 27.75% which was 1.34-fold of that of ultrasonic pretreatment. The results showed the impact of CO(2) laser pretreatment on corn stover to be more effective than ultrasonic pretreatment.

Steam pretreatment of dry and ensiled industrial hemp for ethanol production

Energy Technology Data Exchange (ETDEWEB)

Sipos, Balint; Reczey, Kati [Budapest University of Technology and Economics, Department of Applied Biotechnology and Food Science, Szt. Gellert ter 4., H-1111 Budapest (Hungary); Kreuger, Emma; Bjoernsson, Lovisa [Lund University, Department of Biotechnology, P.O. Box 124, SE-221 00 Lund (Sweden); Svensson, Sven-Erik [Swedish University of Agricultural Sciences, Department of Agriculture - Farming Systems, Technology and Product Quality, P.O. Box 104, SE-230 53 Alnarp (Sweden); Zacchi, Guido [Lund University, Department of Chemical Engineering, P.O. Box 124, SE-221 00 Lund (Sweden)

2010-12-15

Biomass can be converted into liquid and gaseous biofuels with good efficiency. In this study, the conversion of industrial hemp (Cannabis sativa L.), a biomass source that can be cultivated with a high biomass yield per hectare, was used. Steam pretreatment of dry and ensiled hemp was investigated prior to ethanol production. The pretreatment efficiency was evaluated in terms of sugar recovery and polysaccharide conversion in the enzymatic hydrolysis step. For both materials, impregnation with 2% SO{sub 2} followed by steam pretreatment at 210 C for 5 min were found to be the optimal conditions leading to the highest overall yield of glucose. Simultaneous saccharification and fermentation experiments carried out with optimised pretreatment conditions resulted in ethanol yields of 163 g kg{sup -1} ensiled hemp (dry matter) (71% of the theoretical maximum) and 171 g kg{sup -1} dry hemp (74%), which corresponds to 206-216 l Mg{sup -1} ethanol based on initial dry material. (author)

Pretreatment of Biomass by Aqueous Ammonia for Bioethanol Production

Science.gov (United States)

Kim, Tae Hyun; Gupta, Rajesh; Lee, Y. Y.

The methods of pretreatment of lignocellulosic biomass using aqueous ammonia are described. The main effect of ammonia treatment of biomass is delignification without significantly affecting the carbohydrate contents. It is a very effective pretreatment method especially for substrates that have low lignin contents such as agricultural residues and herbaceous feedstock. The ammonia-based pretreatment is well suited for simultaneous saccharification and co-fermentation (SSCF) because the treated biomass retains cellulose as well as hemicellulose. It has been demonstrated that overall ethanol yield above 75% of the theoretical maximum on the basis of total carbohydrate is achievable from corn stover pretreated with aqueous ammonia by way of SSCF. There are two different types of pretreatment methods based on aqueous ammonia: (1) high severity, low contact time process (ammonia recycle percolation; ARP), (2) low severity, high treatment time process (soaking in aqueous ammonia; SAA). Both of these methods are described and discussed for their features and effectiveness.

Comparison of Pretreatment Methods on Vetiver Leaves for Efficient Processes of Simultaneous Saccharification and Fermentation by Neurospora sp.

Science.gov (United States)

Restiawaty, E.; Dewi, A.

2017-07-01

Lignocellulosic biomass is a potential raw material for bioethanol production. Neurospora sp. can be used to convert lignocellulosic biomass into bioethanol because of its ability to perform simultaneous saccharification and fermentation. However, lignin content, degree of polymerization, and crystallinity of cellulose contained in lignocellulosic biomass can inhibit cellulosic-biomass digestion by Neurospora sp, so that a suitable pretreatment method of lignocellulosic biomass is needed. The focus of this research was to investigate the suitable pretreatment method for vetiver leaves (Vetiveria zizanioides L. Nash) used as a raw material producing bioethanol in the process of simultaneous saccharification and fermentation (SSF) by Neurospora sp.. Vetiver plants obtained from Garut are deliberately cultivated to produce essential oils extracted from the roots of this plant. Since the vetiver leaves do not contain oil, some of harvested leaves are usually used for crafts and cattle feed, and the rest are burned. This study intended to look at other potential of vetiver leaves as a source of renewable energy. Pretreatments of the vetiver leaves were conducted using hot water, dilute acid, alkaline & dilute acid, and alkaline peroxide, in which each method was accompanied by thermal treatment. The results showed that the alkaline peroxide treatment is a suitable for vetiver leaves as indicated by the increase of cellulose content up to 65.1%, while the contents of hot water soluble, hemicellulose, lignin, and ash are 8.7%, 18.3%, 6.8%, and 1.1%, respectively. Using this pretreatment method, the vetiver leaves can be converted into bioethanol by SSF process using Neurospora sp. with a concentration of bioethanol of 6.7 g/L operated at room temperature.

Calculation of noninformative prior of reliability parameter and initiating event frequency with Jeffreys method

International Nuclear Information System (INIS)

He Jie; Zhang Binbin

2013-01-01

In the probabilistic safety assessment (PSA) of nuclear power plants, there are few historical records on some initiating event frequencies or component failures in industry. In order to determine the noninformative priors of such reliability parameters and initiating event frequencies, the Jeffreys method in Bayesian statistics was employed. The mathematical mechanism of the Jeffreys prior and the simplified constrained noninformative distribution (SCNID) were elaborated in this paper. The Jeffreys noninformative formulas and the credible intervals of the Gamma-Poisson and Beta-Binomial models were introduced. As an example, the small break loss-of-coolant accident (SLOCA) was employed to show the application of the Jeffreys prior in determining an initiating event frequency. The result shows that the Jeffreys method is an effective method for noninformative prior calculation. (authors)

Effect of pretreating of host oil on coprocessing

Energy Technology Data Exchange (ETDEWEB)

Hajdu, P.E.; Tierney, J.W.; Wender, I. [Univ. of Pittsburgh, PA (United States)

1995-12-31

The principal objective of this research was to determine if coprocessing performance (i.e., coal conversion and oil yield) could be significantly improved by pretreating the heavy resid prior to reacting it with coal. For this purpose, two petroleum vacuum resids (1000{degrees}F+), one from the Amoco Co. and another from the Citgo Co., were used as such and after they had been pretreated by catalytic hydrogenation and hydrocracking reactions. The pretreatments were aimed at improving the host oil by; (1) converting any aromatic structures in the petroleum to hydroaromatic compounds capable of donating hydrogen, (2) cracking the heavy oil to lower molecular weight material that might serve as a better solvent, (3) reducing the coking propensity of the heavy oil through the hydrogenation of polynuclear aromatic compounds, and (4) removing metals and heteroatoms that might poison a coprocessing catalyst. Highly dispersed catalysts, including fine particle Fe- and Mo-based, and dicobalt octacarbonyl, Co{sub 2}(CO){sub 8}, were used in this study. The untreated and pretreated resids were extensively characterized in order to determine chemical changes brought about by the pretreatments. The modified heavy oils were then coprocessed with an Illinois No. 6 coal as well as with a Wyodak coal, and compared to coprocessing with untreated resids under the same hydroliquefaction conditions. The amount of oil derived from coal was estimated by measuring the level of phenolic oxygen (derived mainly from coal) present in the oil products. Results are presented and discussed.

Pretreatment of lignocellulosic material with fungi capable of higher lignin degradation and lower carbohydrate degradation improves substrate acid hydrolysis and the eventual conversion to ethanol

Energy Technology Data Exchange (ETDEWEB)

Kuhar, S.; Nair, L.M.; Kuhad, R.C. [Delhi Univ., New Delhi (India). Dept. of Microbiology, Lignocellulose Biotechnology Laboratory

2008-04-15

Lignocellulosic biomass is the most abundant energy resource in the world and is a potential source of carbon substrate for the production of ethanol via fermentation. However, the presence of lignin restricts access to holocellulose. It is necessary to break or remove the lignin in plant residues prior to their hydrolysis. Pretreatment is needed to liberate cellulose and hemicellulose from the lignins. This paper discussed a biological delignification method that avoided the use of toxic and corrosive chemicals. The in situ microbial delignification process used white rot fungi as a basidiomycetes for biological pretreatment. The study examined the capability of 4 basidiomycetes fungi, notably: (1) Phanerochaete chrysosporium; (2) Pycnoporus cinnabarinus; (3) fungal isolate RCK-1; and (4) fungal isolate RCK-3. The fungi were used to delignify wheat straw and improve hydrolysis procedures. Attempts were also made to ferment the acid hydrolysates from fungal-pretreated lignocellulosic materials. Results of the experiment showed that higher yields of ethanol were obtained using selective lignin-degrading fungi as a pretreatment method. 39 refs., 3 tabs., 4 figs.

Review of pretreatment processes for lignocellulosic ethanol production, and development of an innovative method

International Nuclear Information System (INIS)

Chiaramonti, David; Prussi, Matteo; Ferrero, Simone; Oriani, Luis; Ottonello, Piero; Torre, Paolo; Cherchi, Francesco

2012-01-01

Biomass pretreatment aims at separating and providing easier access to the main biomass components (cellulose, hemicellulose and lignin), eventually removing lignin, preserving the hemicellulose, reducing the cellulose crystallinity and increasing the porosity of the material. Pretreatment is an essential step towards the development and industrialization of efficient 2nd generation lignocellulosic ethanol processes. The present work reviewed the main options available in pretreatment. Autohydrolysis and steam explosion were then selected for further investigation. Experimental work was carried out on batch scale reactors, using Miscanthus as biomass feedstock: the effects on sugar solubilization and degradation products generation have been examined for each of these two pretreatment systems. A new process using only water and steam as reacting media was then developed, experimentally tested, and results compared to those achieved by the autohydrolysis and steam explosion processes. Products obtained with the new pretreatment contained a lower amount of usual fermentation inhibitor compounds compared to that typically obtained in steam explosion. This result was achieved under operating conditions that at the same time allowed a good xylan yield, preventing degradation of hemicelluloses. The new pretreatment process was also able to act as an equalization step, as the solid material from the pretreatment phase had a similar composition even under different operating conditions. As regards the effect of pretreatment on enzymatic hydrolysis, the new process achieved yields similar to steam explosion on glucans: however, this was obtained reducing the formation of degradation products from sugars, mainly from C5 sugars. These results made the proposed pretreatment system suitable for further development and industrialization on pilot and industrial scale.

Lignin Sulfonation and SO2 Addition Enhance the Hydrolyzability of Deacetylated and Then Steam-Pretreated Poplar with Reduced Inhibitor Formation.

Science.gov (United States)

Tang, Yong; Dou, Xiaoli; Hu, Jinguang; Jiang, Jianxin; Saddler, Jack N

2018-01-01

The merit of deacetylation of corn stover prior to pretreatment is decreasing the formation of inhibitors and improving enzyme hydrolysis, proved in dilute acid pretreatment. However, few studies are done on how deacetylation would affect bioconversion process containing steam explosion. In this study, the effect of deacetylation on steam explosion was conducted using poplar as substrate. About 57 to 90% of acetyl group in poplar, depending on alkaline types and concentration, was removed by dilute alkaline deacetylation in 6 h. Deacetylation eliminated over 85% of inhibitor formation during downstream steam explosion. However, deacetylation prior to steam explosion decreased the dissolution of hemicellulose, thus reducing the cellulose accessibility of pretreated poplar, finally resulting in 5-20% decrease in glucose yield and 20-35% decrease in xylose yield. The addition of 5% SO 2 during steam explosion significantly improved the hydrolysis of deacetylated and pretreated poplar without significantly increasing the concentration of inhibitors. Incorporating 45 mmol/kg sulfoacid group in lignin fraction of deacetylated and then pretreated poplar dramatically improved the xylose yield to about 100% and increased the glucose yield by 30%.

Improving enzymatic saccharification of cassava stem using peroxide and microwave assisted pre-treatment techniques

Directory of Open Access Journals (Sweden)

Sudha A.

2017-01-01

Full Text Available The effectiveness of microwave assisted alkali (MAA and alkaline hydrogen peroxide (AHP pre-treatment methods in improving the enzymatic saccharification of cassava stem was investigated. Ground cassava stems were by MAA method by varying microwave power, NaOH concentration and pre-treatment time. AHP method was performed at various H2O2 concentrations, pre-treatment temperatures and times. The results showed that reducing sugar yield was higher from MAA pretreated stem when compared with AHP pre-treatment, which demonstrated that MAA pre-treatment was effective in releasing sugars. SEM studies on the pre-treated samples revealed extensive distortion of fibres in MAA pre-treated than AHP pre-treated samples, which showed pores and cracks in the fibrous structure. Spectral studies showed the change in the chemical structure of pre-treated samples. The work revealed that the studied pre-treatment methods were effective in improving the enzymatic saccharification of cassava stem.

Pretreatment of Oil Palm Frond (OPF) with Ionic Liquid

Science.gov (United States)

Azmi, I. S.; Azizan, A.; Salleh, R. Mohd

2018-05-01

Pretreatment is the key to unlock the recalcitrance of lignocellulose for cellulosic biofuel production. Increasing attention has been drawn to ionic liquids (ILs) for pretreatment of lignocellulosic biomass because this approach was considered as a green engineering method over other conventional methods. In this work, Oil palm frond (OPF) was pretreated by using the ionic liquid 1-ethyl-3-methylimidazolium acetate [EMIM] Ac at the temperature of 99˚C for 3 hours. The characterization of the untreated and pretreated OPF was conducted by using different techniques which are Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The pretreatment of OPF with [EMIM] Ac was demonstrated to be effective evidenced by the significant reduction of Lateral Order Index (LOI) from FTIR, reduction of Crystallinity Index (CI) based on XRD and the significant morphology changes indicated by SEM. The CI value for the pretreated OPF decreased from 0.47 (untreated sample) to 0.28 while the LOI value decreased from 1.10 to 0.24 after pretreatment with [EMIM]Ac and the SEM morphology showed that the pretreated OPF becomes distorted and disordered.

Switchgrass storage effects on the recovery of carbohydrates after liquid hot water pretreatment and enzymatic hydrolysis

Directory of Open Access Journals (Sweden)

Danielle Julie Carrier

2016-08-01

Full Text Available Perennial grasses that would be used for bioenergy and bioproducts production will need to be stored for various periods of time to ensure a continual feedstock supply to a bioprocessing facility. The effects of storage practices on grass composition and the response of grasses to subsequent bioprocesses such as pretreatment and enzymatic hydrolysis needs to be understood to develop the most efficient storage protocols. This study examined the effect of outdoor storage of round switchgrass bales on composition before and after liquid hot water pretreatment (LHW and enzymatic hydrolysis. This study also examined the effect of washing LHW pretreated biomass prior to enzymatic hydrolysis. It was determined that switchgrass composition after baling was stable. As expected, glucan and lignin contents increased after LHW due to decreases in xylan and galactan. Washing biomass prior to enzymatic hydrolysis reduced saccharification, especially in samples from the interior of the bale, by at least 5%.

Decreased sensitivity to nicotine-induced seizures as a consequence of nicotine pretreatment in long-sleep and short-sleep mice.

Science.gov (United States)

de Fiebre, C M; Collins, A C

1988-01-01

Male and female long-sleep (LS) and short-sleep (SS) mice were pretreated with a subseizure-producing dose of nicotine (2.0 mg/kg) 7.5, 15 and 30 minutes prior to challenge with seizure-producing doses of this drug. Nicotine pretreated animals were less susceptible to nicotine-induced seizures than were saline pretreated animals. The latency to seizure following nicotine challenge was greater in nicotine pretreated animals than in saline controls. Nicotine pretreated LS mice show a greater decrease in nicotine-induced seizure susceptibility than do nicotine pretreated SS mice. This decrease in seizure susceptibility is consistent with induction of nicotinic receptor desensitization via nicotine pretreatment. It is hypothesized that LS and SS mice might differ in sensitivity to nicotine in part because they differ in baseline levels of desensitized versus functional nicotinic receptors.

Pretreatment process for mineral analysis in FFH using INAA-method and evaluation of mineral intakes

International Nuclear Information System (INIS)

Lee, Ok Hee; Youn, Kyung Jin; Lee, Ji Bum; Kim, Mi Jin

2010-05-01

This study were aimed to set up the pre-treatment process for FFH and analyse Pretreatment processes for the analysis of food mineral contents by INAA were established according to FFH state using freeze-drying and homogenization. The Se contents showed higher precision with INAA-method than ICP-method. The content of Ca, Na, Mg, Fe, Zn, Cu, Mn, Cr, Co in FFH measured using INAA-method showed that the mineral contents in the amount of recommended intakes by manufacturer were not significantly different according to FFH type. The average Ca contents was the highest in Yousanguns > nutritional supplement> glucosamines. The average K content of FFH with one serving size were the highest in glucosamines>aloes> nutritional supplements. I content among FFH was the highest in nutritional supplements. The average Mg contents were highest in Chlorella-Spirurina and Aloes. The average Cu content of FFH was the highest in Yeasts. The contents of Fe, Zn and Se were the highest in nutritional supplements. The mineral contents in recommended intake amounts by manufacturer were over the maximum contents regulated by Korean FDA in some imported FFH products. their mineral contents of FFH using NAA-method and to assess the mineral intakes by FFH

Pretreatment process for mineral analysis in FFH using INAA-method and evaluation of mineral intakes

Energy Technology Data Exchange (ETDEWEB)

Lee, Ok Hee; Youn, Kyung Jin; Lee, Ji Bum; Kim, Mi Jin [Yongin University, Yongin (Korea, Republic of)

2010-05-15

This study were aimed to set up the pre-treatment process for FFH and analyse Pretreatment processes for the analysis of food mineral contents by INAA were established according to FFH state using freeze-drying and homogenization. The Se contents showed higher precision with INAA-method than ICP-method. The content of Ca, Na, Mg, Fe, Zn, Cu, Mn, Cr, Co in FFH measured using INAA-method showed that the mineral contents in the amount of recommended intakes by manufacturer were not significantly different according to FFH type. The average Ca contents was the highest in Yousanguns > nutritional supplement> glucosamines. The average K content of FFH with one serving size were the highest in glucosamines>aloes> nutritional supplements. I content among FFH was the highest in nutritional supplements. The average Mg contents were highest in Chlorella-Spirurina and Aloes. The average Cu content of FFH was the highest in Yeasts. The contents of Fe, Zn and Se were the highest in nutritional supplements. The mineral contents in recommended intake amounts by manufacturer were over the maximum contents regulated by Korean FDA in some imported FFH products. their mineral contents of FFH using NAA-method and to assess the mineral intakes by FFH

Vitamin C Pretreatment Enhances the Antibacterial Effect of Cold Atmospheric Plasma

DEFF Research Database (Denmark)

Helgadottir, Saga; Pandit, Santosh; Mokkapati, Venkata R. S. S.

2017-01-01

intervals and to evaluate the effect of combined treatment with vitamin C. We demonstrate that CAP is not very effective against 48 h mature bacterial biofilms of several common opportunistic pathogens: Staphylococcus epidermidis, Escherichia coli, and Pseudomonas aeruginosa. However, if bacterial biofilms...... are pre-treated with vitamin C for 15 min before exposure to CAP, a significantly stronger bactericidal effect can be obtained. Vitamin C pretreatment enhances the bactericidal effect of cold plasma by reducing the viability from 10 to 2% in E. coli biofilm, 50 to 11% in P. aeruginosa, and 61 to 18% in S....... epidermidis biofilm. Since it is not feasible to use extended CAP treatments in medical practice, we argue that the pre-treatment of infectious lesions with vitamin C prior to CAP exposure can be a viable route for efficient eradication of bacterial biofilms in many different applications....

Pretreatment organ function in patients with advanced head and neck cancer: clinical outcome measures and patients' views

Directory of Open Access Journals (Sweden)

Rasch Coen RN

2009-11-01

Full Text Available Abstract Background Aim of this study is to thoroughly assess pretreatment organ function in advanced head and neck cancer through various clinical outcome measures and patients' views. Methods A comprehensive, multidimensional assessment was used, that included quality of life, swallowing, mouth opening, and weight changes. Fifty-five patients with stage III-IV disease were entered in this study prior to organ preserving (chemoradiation treatment. Results All patients showed pretreatment abnormalities or problems, identified by one or more of the outcome measures. Most frequent problems concerned swallowing, pain, and weight loss. Interestingly, clinical outcome measures and patients' perception did no always concur. E.g. videofluoroscopy identified aspiration and laryngeal penetration in 18% of the patients, whereas only 7 patients (13% perceived this as problematic; only 2 out of 7 patients with objective trismus actually perceived trismus. Conclusion The assessment identified several problems already pre-treatment, in this patient population. A thorough assessment of both clinical measures and patients' views appears to be necessary to gain insight in all (perceived pre-existing functional and quality of life problems.

Simultaneous saccharification and co-fermentation of peracetic acid pretreated sugar cane bagasse

Energy Technology Data Exchange (ETDEWEB)

Teixeira, L.C. [Fundacao Centro Tecnologico de Minas Gerais, Belo Horizonte (Brazil); Linden, J.C.; Schroeder, H.A. [Colorado State University, Fort Collins, CO (United States)

1999-07-01

Previous work in our laboratory has demonstrated that peracetic acid improves the enzymatic digestibility of lignocellulosic materials. From the same studies, use of dilute alkali solutions as a pre-pretreatment prior to peracetic acid lignin oxidation increases sugar conversion yields in a synergistic, not additive, manner. Deacetylation of xylan is conducted easily by use of dilute alkali solutions at mild conditions. In this paper, the effectiveness of peracetic acid pretreatment of sugar cane bagasse combined with an alkaline pre-pretreatment, is evaluated through simultaneous saccharification and co-fermentation (SSCF) procedures. A practical 92% of theoretical ethanol yield using recombinant Zymomonas mobilis CP4/pZB5 is achieved using 6% NaOH/I5% peracetic acid pretreated substrate. No sugar accumulation is observed during SSCF; the recombinant microorganism exhibits greater glucose utilization rates than those of xylose. Acetate levels at the end of the co-fermentations are less than 0.2% (w/v). Based on demonstrated reduction of acetyl groups of the biomass, alkaline pre-pretreatments help to reduce peracetic acid requirements. The influence of deacetylation is more pronounced in combined pretreatments using lower peracetic acid loadings. Stereochemical impediments of the acetyl groups in hemicellulase on the activity of specific enzymes may be involved. (author)

Properties of Enzyme Pretreated Wikstroemia sikokiana and Broussonetia papyrifera Bast Fiber Pulps

Directory of Open Access Journals (Sweden)

Lang-Dong Lin

2015-04-01

Full Text Available Xylanase, pectinase complex, and BL11 pectinase were employed for the pretreatment of gampi and paper mulberry bast fiber pulps prior to chlorine dioxide bleaching. The bleaching efficiencies of the pulps with different enzymatic pretreatments were investigated. Accelerated aging by heat-humidity treatment was also conducted to evaluate yellowing phenomena and to estimate the prevention of brightness reversion (brightness retention by enzymatic pretreatment. The order of active chlorine required with respect to pretreatment was pectinase complex > xylanase > BL11 pectinase for soda and soda/oxalate gampi pulps and pectinase complex > BL11 pectinase > xylanase for soda and soda/oxalate paper mulberry pulps. Higher brightness retention values were observed for soda/oxalate pulps compared to soda pulps. The brightness retention levels for gampi pulps and mulberry pulps after ClO2 bleaching with enzymatic pretreatment were higher than the levels of ClO2 and NaClO bleaching pulps. Enzymatic treatments were thus able to reduce the usage of ClO2 and to assist in producing photo-stable paper materials for art and artifact-repairing applications. Thus, enzymatic pretreatment of the pulp has the potential to meet world trends and environmental sustainability for pulp and paper industries.

Ensiling and hydrothermal pretreatment of grass: Consequences for enzymatic biomass conversion and total monosaccharide yields

DEFF Research Database (Denmark)

Ambye-Jensen, Morten; Johansen, Katja Salomon; Didion, Thomas

2014-01-01

Ensiling may act as a pretreatment of fresh grass biomass and increase the enzymatic conversion of structural carbohydrates to fermentable sugars. However, ensiling does not provide sufficient severity to be a standalone pretreatment method. Here, ensiling of grass is combined with hydrothermal...... treatment (HTT) with the aim of improving the enzymatic biomass convertibility and decrease the required temperature of the HTT. Results: Grass silage (Festulolium Hykor) was hydrothermally treated at temperatures of 170, 180, and 190°C for 10 minutes. Relative to HTT treated dry grass, ensiling increased...... convertibility). The effect of ensiling of grass prior to HTT improved the enzymatic conversion of cellulose for HTT at 170 and 180°C, but the increased glucose release did not make up for the loss of water soluble carbohydrates (WSC) during ensiling. Overall, sugar yields (C6 + C5) were similar for HTT of grass...

Techno-economic analysis of organosolv pretreatment process from lignocellulosic biomass

DEFF Research Database (Denmark)

Rodrigues Gurgel da Silva, Andrè; Errico, Massimiliano; Rong, Ben-Guang

2018-01-01

data, we propose a feasible process flowsheet for organosolv pretreatment. Simulation of the pretreatment process provided mass and energy balances for a techno-economic analysis, and the values were compared with the most prevalent and mature pretreatment method: diluted acid. Organosolv pretreatment...... required more energy, 578.1 versus 213.8 MW for diluted acid pretreatment, but resulted in a higher ethanol concentration after the biomass fermentation, 11.1% compared to 5.4%. Total annual costs (TACs) calculations showed advantages for diluted acid pretreatment, but future improvements explored...

HYDROLYSIS OF AGRICULTURAL BIOMASS BY COMBINED PRETREATMENT AND ENZYMATIC METHODS IN ORDER TO PRODUCE BIOFUELS (ETHANOL, BIOGAS

Directory of Open Access Journals (Sweden)

STEFANA JURCOANE

2009-05-01

Full Text Available The use of energy crops (maize straw, wheat straw, barley straw etc. as substrate for renewable energy production (e.g. biogas is more efficient when it is degraded by different hydrolysis methods. However, fibers contained inside energy crops (e.g. cellulose and hemicellulose are only hardly and slowly degraded by anaerobic bacteria. The slow degradation of these substances can decrease the methane yields of agricultural biogas plants.In the present study, we investigated the efficiency of combined pretreatment (different concentrations H2SO4 + 30 minutes at 1210C followed to enzymatic hydrolysis. Testing different concentration of H2SO4, good results were obtained for maize whole crop when we used combined pretreatment (3% H2SO4 + 30 minutes at 1210C followed to enzymatic hydrolysis (3.9 fold higher and for Gavott Maize Straw when we used combined pretreatment (2% H2SO4 + 30 minutes at 1210C followed to enzymatic hydrolysis (3.6 fold higher comparing with untreated samples.

Comparison of Ultrasonic and CO2 Laser Pretreatment Methods on Enzyme Digestibility of Corn Stover

Directory of Open Access Journals (Sweden)

Li-Li Zuo

2012-03-01

Full Text Available To decrease the cost of bioethanol production, biomass recalcitrance needs to be overcome so that the conversion of biomass to bioethanol becomes more efficient. CO2 laser irradiation can disrupt the lignocellulosic physical structure and reduce the average size of fiber. Analyses with Fourier transform infrared spectroscopy, specific surface area, and the microstructure of corn stover were used to elucidate the enhancement mechanism of the pretreatment process by CO2 laser irradiation. The present work demonstrated that the CO2 laser had potential to enhance the bioconversion efficiency of lignocellulosic waste to renewable bioethanol. The saccharification rate of the CO2 laser pretreatment was significantly higher than ultrasonic pretreatment, and reached 27.75% which was 1.34-fold of that of ultrasonic pretreatment. The results showed the impact of CO2 laser pretreatment on corn stover to be more effective than ultrasonic pretreatment.

External Prior Guided Internal Prior Learning for Real-World Noisy Image Denoising

Science.gov (United States)

Xu, Jun; Zhang, Lei; Zhang, David

2018-06-01

Most of existing image denoising methods learn image priors from either external data or the noisy image itself to remove noise. However, priors learned from external data may not be adaptive to the image to be denoised, while priors learned from the given noisy image may not be accurate due to the interference of corrupted noise. Meanwhile, the noise in real-world noisy images is very complex, which is hard to be described by simple distributions such as Gaussian distribution, making real noisy image denoising a very challenging problem. We propose to exploit the information in both external data and the given noisy image, and develop an external prior guided internal prior learning method for real noisy image denoising. We first learn external priors from an independent set of clean natural images. With the aid of learned external priors, we then learn internal priors from the given noisy image to refine the prior model. The external and internal priors are formulated as a set of orthogonal dictionaries to efficiently reconstruct the desired image. Extensive experiments are performed on several real noisy image datasets. The proposed method demonstrates highly competitive denoising performance, outperforming state-of-the-art denoising methods including those designed for real noisy images.

Effect of EDTA Conditioning and Carbodiimide Pretreatment on the Bonding Performance of All-in-One Self-Etch Adhesives

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Shipra Singh

2015-01-01

Full Text Available Objective. This study evaluated the effect of ethylenediaminetetraacetic acid (EDTA conditioning and carbodiimide (EDC pretreatment on the shear bond strength of two all-in-one self-etch adhesives to dentin. Methods. Flat coronal dentin surfaces were prepared on one hundred and sixty extracted human molars. Teeth were randomly divided into eight groups according to two different self-etch adhesives used [G-Bond and OptiBond-All-In-One] and four different surface pretreatments: (a adhesive applied following manufacturer’s instructions; (b dentin conditioning with 24% EDTA gel prior to application of adhesive; (c EDC pretreatment followed by application of adhesive; (d application of EDC on EDTA conditioned dentin surface followed by application of adhesive. Composite restorations were placed in all the samples. Ten samples from each group were subjected to immediate and delayed (6-month storage in artificial saliva shear bond strength evaluation. Data collected was subjected to statistical analysis using three-way ANOVA and post hoc Tukey’s test at a significance level of p<0.05.  Results and Conclusion. EDTA preconditioning as well as EDC pretreatment alone had no significant effect on the immediate and delayed bond strengths of either of the adhesives. However, EDC pretreatment on EDTA conditioned dentin surface resulted in preservation of resin-dentin bond strength of both adhesives with no significant fall over six months.

[DNA quantification of blood samples pre-treated with pyramidon].

Science.gov (United States)

Zhu, Chuan-Hong; Zheng, Dao-Li; Ni, Rao-Zhi; Wang, Hai-Sheng; Ning, Ping; Fang, Hui; Liu, Yan

2014-06-01

To study DNA quantification and STR typing of samples pre-treated with pyramidon. The blood samples of ten unrelated individuals were anticoagulated in EDTA. The blood stains were made on the filter paper. The experimental groups were divided into six groups in accordance with the storage time, 30 min, 1 h, 3 h, 6 h, 12 h and 24h after pre-treated with pyramidon. DNA was extracted by three methods: magnetic bead-based extraction, QIAcube DNA purification method and Chelex-100 method. The quantification of DNA was made by fluorescent quantitative PCR. STR typing was detected by PCR-STR fluorescent technology. In the same DNA extraction method, the sample DNA decreased gradually with times after pre-treatment with pyramidon. In the same storage time, the DNA quantification in different extraction methods had significant differences. Sixteen loci DNA typing were detected in 90.56% of samples. Pyramidon pre-treatment could cause DNA degradation, but effective STR typing can be achieved within 24 h. The magnetic bead-based extraction is the best method for STR profiling and DNA extraction.

Pre-treatment with a sinus node blockade, ivabradine, before coronary CT angiography

DEFF Research Database (Denmark)

Lambrechtsen, J; Egstrup, K

2013-01-01

To evaluate whether a simple pre-treatment regimen of sinus node inhibition by ivabradine taken at home for only 1 day resulted in a lower pre-scanning heart rate (HR) and reduced the need for intravenous beta-blockers (BB) prior to coronary computed tomography angiography (CTA)....

Investigation of Surface Pre-Treatment Methods for Wafer-Level Cu-Cu Thermo-Compression Bonding

Directory of Open Access Journals (Sweden)

Koki Tanaka

2016-12-01

Full Text Available To increase the yield of the wafer-level Cu-Cu thermo-compression bonding method, certain surface pre-treatment methods for Cu are studied which can be exposed to the atmosphere before bonding. To inhibit re-oxidation under atmospheric conditions, the reduced pure Cu surface is treated by H2/Ar plasma, NH3 plasma and thiol solution, respectively, and is covered by Cu hydride, Cu nitride and a self-assembled monolayer (SAM accordingly. A pair of the treated wafers is then bonded by the thermo-compression bonding method, and evaluated by the tensile test. Results show that the bond strengths of the wafers treated by NH3 plasma and SAM are not sufficient due to the remaining surface protection layers such as Cu nitride and SAMs resulting from the pre-treatment. In contrast, the H2/Ar plasma–treated wafer showed the same strength as the one with formic acid vapor treatment, even when exposed to the atmosphere for 30 min. In the thermal desorption spectroscopy (TDS measurement of the H2/Ar plasma–treated Cu sample, the total number of the detected H2 was 3.1 times more than the citric acid–treated one. Results of the TDS measurement indicate that the modified Cu surface is terminated by chemisorbed hydrogen atoms, which leads to high bonding strength.

Mechanism of melphalan crosslink enhancement by misonidazole pretreatment

International Nuclear Information System (INIS)

Taylor, Y.C.; Sawyer, J.M.; Hsu, B.; Brown, J.M.

1984-01-01

Sensitization of Chinese hamster ovary cells to melphalan (L-PAM) toxicity by prior treatment with misonidazole is associated with increased levels of DNA crosslinks believed to be the critical lesion for bifunctional alkylating agent toxicity. Enhanced L-PAM crosslinking of DNA could occur by a variety of mechanisms in MISO-pretreated cells including: (1) increased transport or binding of L-PAM, (2) decreased repair of L-PAM monoadducts which would allow more time for their conversion to crosslinks, (3) decreased crosslink repair (unhooking of one arm), or (4) chemical modification of the DNA structure, presumably by bound MISO derivatives, such that crosslink formation is facilitated. Previous studies have eliminated mechanisms (1) and (3). Mechanism (4) was investigated by following MISO-pretreatments of whole cells with L-PAM treatments of the isolated DNA from these cells. Treatment of bare DNA with L-PAM modeled very well the crosslinking behavior in whole cells although it was somewhat more efficient. In the presence of double stranded DNA and absence of repair systems during and after the L-PAM exposure, it was determined that MISO-pretreatments did not increase the crosslinking efficiency of L-PAM

[Enhancement of anaerobic digestion of excess sludge by acid-alkali pretreatment].

Science.gov (United States)

Yuan, Guang-Huan; Zhou, Xing-Qiu; Wu, Jian-Dong

2012-06-01

In order to enhance the efficiency of anaerobic digestion of excess sludge, acid-alkali pretreatment method was studied. Three different pretreatment methods (alkali alone,acid-alkali, alkali-acid) were compared to investigate their impacts on hydrolysis and acidification of activated sludge. In addition, their influences on methane-producing in subsequent anaerobic digestion process were also studied. The results showed that the soluble chemical oxygen demand (SCOD) of alkaline treatment alone was about 16% higher than the combining of acid and alkali treatment, SCOD concentration increased to 5406.1 mg x L(-1) after 8 d pretreatment. After treated by acid (pH 4.0, 4 d) and alkali (pH 10.0, 4 d), the acetic acid production and its content in short-chain fatty acids (SCFAs) were higher than other pretreatment methods. And the acetic acid production (as COD/VSS) could reach 74.4 mg x g(-1), accounting for 60.5% of SCFAs. After acid-alkali pretreatment, the C: N ratio of the sludge mixed liquor was about 25, and the C: P ratio was between 35-40, which was more favorable than C: N and C: P ratio of alkali alone and alkali-acid to subsequent anaerobic digestion. The control experiments showed that, after acid-alkali pretreatment, anaerobic digestion cumulative methane yield (CH4/VSS(in)) reached to 136.1 mL x g(-1) at 15 d, which was about 2.5-, 1.6-, and 1.7-fold of the blank (unpretreated), alkali alone pretreatment and alkali-acid pretreatment, respectively. After acid-alkali pretreatment for 8 d and anaerobic digestion for 15 d, the removal efficiency of VSS was about 60.9%, and the sludge reduction effect was better than other pretreatments. It is obvious that the acid-alkali pretreatment method was more favorable to anaerobic digestion and sludge reduction.

Ensiling as pretreatment of grass for lignocellulosic biomass conversion

DEFF Research Database (Denmark)

Ambye-Jensen, Morten

for subsequent enzymatic saccharification of cellulose and hemicellulose, by using the temperate grass Festulolium Hykor. The method was additionally combined with hydrothermal treatment, in order to decrease the required severity of an industrial applied pretreatment method. The first part of the project...... conditions providing the best possible pretreatment effect. The parameters were biomass composition, varied by ensiling of four seasonal cuts of grass, different dry matter (DM) content at ensiling, and an addition of different lactic acid bacteria species. First of all, the study confirmed that ensiling can...... act as a method of pretreatment and improve the enzymatic cellulose convertibility of grass. Furthermore, low DM ensiling was found to improve the effects of pretreatment due to a higher production of organic acids in the silage. The effect of applied lactic acid bacteria species was, however...

Nonhazardous Urine Pretreatment Method for Future Exploration Systems, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — A nonhazardous urine pretreatment system prototype is proposed that will stabilize urine against biological growth or chemical instabilities without using hazardous...

Biomass shock pretreatment

Science.gov (United States)

Holtzapple, Mark T.; Madison, Maxine Jones; Ramirez, Rocio Sierra; Deimund, Mark A.; Falls, Matthew; Dunkelman, John J.

2014-07-01

Methods and apparatus for treating biomass that may include introducing a biomass to a chamber; exposing the biomass in the chamber to a shock event to produce a shocked biomass; and transferring the shocked biomass from the chamber. In some aspects, the method may include pretreating the biomass with a chemical before introducing the biomass to the chamber and/or after transferring shocked biomass from the chamber.

Nonhazardous Urine Pretreatment Method for Future Exploration Systems, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — A novel urine pretreatment that will prevent biological growth or chemical instabilities in urine without using hazardous chemicals is proposed. Untreated urine...

Acrylamide generation in pre-treated potato chips

DEFF Research Database (Denmark)

Pedreschi, Franco; Kaack, Karl; Granby, Kit

2008-01-01

Acrylamide formation in potato slices fried at two different temperatures ( 170 and 190 degrees C) was investigated under different pre-processing conditions. Potato slices (Saturna variety, diameter: 37 mm, width: 2.2 mm) were either fried at 170 degrees C per 5 min or 190 degrees C per 3.5 min...... to reach a final moisture content of 1.8 g water/100g ( wet basis). Prior to frying, potato slices were treated in one of the following ways: (i) Raw slices without any pre-treatment were considered as the control; (ii) Blanching: which was accomplished in 2 temperature-time combinations: 60 degrees C....... Acrylamide content in potato chips was determined after frying at 170 or 190 degrees C. Frying at 190 degrees C increased by almost 130 percent the acrylamide content of all the pre-treated samples ( average value) fried at 170 degrees C. Soaking of blanched potato slices in the 3 g/100 g of NaCl solution...

Systematic approach to optimize a pretreatment method for ultrasensitive liquid chromatography with tandem mass spectrometry analysis of multiple target compounds in biological samples.

Science.gov (United States)

Togashi, Kazutaka; Mutaguchi, Kuninori; Komuro, Setsuko; Kataoka, Makoto; Yamazaki, Hiroshi; Yamashita, Shinji

2016-08-01

In current approaches for new drug development, highly sensitive and robust analytical methods for the determination of test compounds in biological samples are essential. These analytical methods should be optimized for every target compound. However, for biological samples that contain multiple compounds as new drug candidates obtained by cassette dosing tests, it would be preferable to develop a single method that allows the determination of all compounds at once. This study aims to establish a systematic approach that enables a selection of the most appropriate pretreatment method for multiple target compounds without the use of their chemical information. We investigated the retention times of 27 known compounds under different mobile phase conditions and determined the required pretreatment of human plasma samples using several solid-phase and liquid-liquid extractions. From the relationship between retention time and recovery in a principal component analysis, appropriate pretreatments were categorized into several types. Based on the category, we have optimized a pretreatment method for the identification of three calcium channel blockers in human plasma. Plasma concentrations of these drugs in a cassette-dose clinical study at microdose level were successfully determined with a lower limit of quantitation of 0.2 pg/mL for diltiazem, 1 pg/mL for nicardipine, and 2 pg/mL for nifedipine. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Enzymatic hydrolysis of pretreated soybean straw

International Nuclear Information System (INIS)

Xu Zhong; Wang Qunhui; Jiang Zhaohua; Yang Xuexin; Ji Yongzhen

2007-01-01

In order to produce lactic acid, from agricultural residues such as soybean straw, which is a raw material for biodegradable plastic production, it is necessary to decompose the soybean straw into soluble sugars. Enzymatic hydrolysis is one of the methods in common use, while pretreatment is the effective way to increase the hydrolysis rate. The optimal conditions of pretreatment using ammonia and enzymatic hydrolysis of soybean straw were determined. Compared with the untreated straw, cellulose in straw pretreated by ammonia liquor (10%) soaking for 24 h at room temperature increased 70.27%, whereas hemicellulose and lignin in pretreated straw decreased to 41.45% and 30.16%, respectively. The results of infrared spectra (IR), scanning electron microscope (SEM) and X-ray diffraction (XRD) analysis also showed that the structure and the surface of the straw were changed through pretreatment that is in favor of the following enzymatic hydrolysis. maximum enzymatic hydrolysis rate of 51.22% was achieved at a substrate concentration of 5% (w/v) at 50 deg. C and pH 4.8 using cellulase (50 fpu/g of substrate) for 36 h

FRACTIONAL CRYSTALLIZATION TESTING WITH INTERIM PRETREATMENT SYSTEM FEEDS

International Nuclear Information System (INIS)

HERTING DL

2008-01-01

The fractional crystallization process was developed as a pretreatment method for saltcake waste retrieved from Hanford single-shell tanks (SST). The process separates the retrieved SST waste into a high-level waste stream containing the bulk of the radionuclides and a low-activity waste stream containing the bulk of the nonradioactive sodium salts. The Interim Pretreatment System project shifted the focus on pretreatment planning from SST waste to double-shell tank waste

Bonding brackets on white spot lesions pretreated by means of two methods

Directory of Open Access Journals (Sweden)

Julia Sotero Vianna

2016-04-01

Full Text Available Abstract Objective: The aim of this study was to evaluate the shear bond strength (SBS of brackets bonded to demineralized enamel pretreated with low viscosity Icon Infiltrant resin (DMG and glass ionomer cement (Clinpro XT Varnish, 3M Unitek with and without aging. Methods: A total of 75 bovine enamel specimens were allocated into five groups (n = 15. Group 1 was the control group in which the enamel surface was not demineralized. In the other four groups, the surfaces were submitted to cariogenic challenge and white spot lesions were treated. Groups 2 and 3 were treated with Icon Infiltrant resin; Groups 4 and 5, with Clinpro XT Varnish. After treatment, Groups 3 and 5 were artificially aged. Brackets were bonded with Transbond XT adhesive system and SBS was evaluated by means of a universal testing machine. Statistical analysis was performed by one-way analysis of variance followed by Tukey post-hoc test. Results: All groups tested presented shear bond strengths similar to or higher than the control group. Specimens of Group 4 had significantly higher shear bond strength values (p < 0.05 than the others. Conclusion: Pretreatment of white spot lesions, with or without aging, did not decrease the SBS of brackets.

Effect of Prior Aspirin Treatment on Patients With Acute Coronary Syndromes: Insights From the PROSPECT Study.

Science.gov (United States)

Brener, Sorin J; Maehara, Akiko; Mintz, Gary S; Weisz, Giora; de Bruyne, Bernard; Serruys, Patrick W; Stone, Gregg W

2015-12-01

Prior aspirin treatment is considered a risk factor for adverse outcomes in acute coronary syndrome (ACS) patients. The relationships between aspirin pretreatment and findings on quantitative coronary angiography (QCA) and intravascular ultrasound (IVUS), as well as clinical outcomes, are not well understood. In the PROSPECT trial, QCA and triple-vessel IVUS imaging were performed after successful percutaneous coronary intervention (PCI) of the culprit lesion(s) in ACS patients. We compared patients receiving aspirin within 7 days of enrollment to those naive to aspirin. Propensity score matching was performed to adjust for differences in baseline characteristics. Aspirin-pretreated patients (n = 236; 35%) were older and more likely to have known coronary disease than those without pretreatment (P≤.01 for all). Pretreated patients had more untreated non-culprit lesions with angiographic and IVUS characteristics predictive of future events (53.1% vs 38.6%; PPROSPECT trial, aspirin pretreatment identifies an older population with more advanced coronary disease. Aspirin pretreatment was not an independent predictor of MACE in ACS patients treated with an early invasive strategy. The extent to which aspirin pretreatment is a risk factor for adverse events after PCI in ACS should be revisited.

Pretreatment of Reed by Wet Oxidation and Subsequent Utilization of the Pretreated Fibers for Ethanol Production

DEFF Research Database (Denmark)

Szijarto, Nora; Kádár, Zsófia; Varga, Eniko

2009-01-01

lignocelluloses usually do. In the present study, wet oxidation was investigated as the pretreatment method to enhance the enzymatic digestibility of reed cellulose to soluble sugars and thus improve the convertibility of reed to ethanol. The most effective treatment increased the digestibility of reed cellulose...... of cellulose to glucose was 82.4%. Simultaneous saccharification and fermentation of pretreated solids resulted in a final ethanol concentration as high as 8.7 g/L, yielding 73% of the theoretical....

Hydrogen–argon plasma pre-treatment for improving the anti-corrosion properties of thin Al2O3 films deposited using atomic layer deposition on steel

International Nuclear Information System (INIS)

Härkönen, Emma; Potts, Stephen E.; Kessels, Wilhelmus M.M.; Díaz, Belén; Seyeux, Antoine; Światowska, Jolanta; Maurice, Vincent; Marcus, Philippe; Radnóczi, György; Tóth, Lajos; Kariniemi, Maarit; Niinistö, Jaakko; Ritala, Mikko

2013-01-01

The effect of H 2 –Ar plasma pre-treatment prior to thermal atomic layer deposition (ALD) and plasma-enhanced atomic layer deposition (PEALD) of Al 2 O 3 films on steel for corrosion protection was investigated. Time-of-flight secondary ion mass spectrometry and transmission electron microscopy were used to observe the changes in the interface. The electrochemical properties of the samples were studied with polarization measurements, and the coating porosities were calculated from the polarization results for easier comparison of the coatings. Prior to thermal ALD the plasma pre-treatment was observed to reduce the amount of impurities at the interface and coating porosity by 1–3 orders of magnitude. The anti-corrosion properties of the PEALD coatings could also be improved by the pre-treatment. However, exposure of the pre-treatment plasma activated steel surface to oxygen plasma species in PEALD led to facile oxide layer formation in the interface. The oxide layer formed this way was thicker than the native oxide layer and appeared to be detrimental to the protective properties of the coating. The best performance for PEALD Al 2 O 3 coatings was achieved when, after the plasma pre-treatment, the surface was given time to regrow a thin protective interfacial oxide prior to exposure to the oxygen plasma. The different effects that thermal and plasma-enhanced ALD have on the substrate-coating interface were compared. The reactivity of the oxygen precursor was shown to have a significant influence on substrate surface in the early stages of film growth and thereafter also on the overall quality of the protective film. - Highlights: • Influence of H 2 –Ar plasma pre-treatment to ALD coatings on steel was studied. • The pre-treatment modified the coating–substrate interface composition and thickness. • The pre-treatment improved the barrier properties of the coatings

Ultrasound pre-treatment for anaerobic digestion improvement.

Science.gov (United States)

Pérez-Elvira, S; Fdz-Polanco, M; Plaza, F I; Garralón, G; Fdz-Polanco, F

2009-01-01

Prior research indicates that ultrasounds can be used in batch reactors as pre-treatment before anaerobic digestion, but the specific energy required at laboratory-scale is too high. This work evaluates both the continuous ultrasound device performance (efficiency and solubilisation) and the operation of anaerobic digesters continuously fed with sonicated sludge, and presents energy balance considerations. The results of sludge solubilisation after the sonication treatment indicate that, applying identical specific energy, it is better to increase the power than the residence time. Working with secondary sludge, batch biodegradability tests show that by applying 30 kWh/m3 of sludge, it is possible to increase biogas production by 42%. Data from continuous pilot-scale anaerobic reactors (V=100 L) indicate that operating with a conventional HRT=20 d, a reactor fed with pre-treated sludge increases the volatile solids removal and the biogas production by 25 and 37% respectively. Operating with HRT=15 d, the removal efficiency is similar to the obtained with a reactor fed with non-hydrolysed sludge at HTR=20 d, although the specific biogas productivity per volume of reactor is higher for the pretreated sludge. Regarding the energy balance, although for laboratory-scale devices it is negative, full-scale suppliers state a net generation of 3-10 kW per kW of energy used.

Prior Elicitation, Assessment and Inference with a Dirichlet Prior

Directory of Open Access Journals (Sweden)

Michael Evans

2017-10-01

Full Text Available Methods are developed for eliciting a Dirichlet prior based upon stating bounds on the individual probabilities that hold with high prior probability. This approach to selecting a prior is applied to a contingency table problem where it is demonstrated how to assess the prior with respect to the bias it induces as well as how to check for prior-data conflict. It is shown that the assessment of a hypothesis via relative belief can easily take into account what it means for the falsity of the hypothesis to correspond to a difference of practical importance and provide evidence in favor of a hypothesis.

Pretreatment method for radioactive iodine-containing liquid wastes and pretreatment device

International Nuclear Information System (INIS)

Wakaida, Yasuo.

1996-01-01

Heretofore, radioactive iodine-containing liquid wastes have been discharged directly to a storing and decaying storage vessel to conduct a water draining treatment. In the present invention, the radioactive iodine-containing liquid wastes to be discharged are not discharged to the storage vessel directly but injected to a filling tank, as a pretreatment, to distinguish whether proteins are mixed in the liquid wastes or not. When proteins are mixed, miscellaneous materials such as proteins are recovered and removed by a protein processing system. When proteins are not mixed, radioactive iodine is recovered and removed directly by an iodine processing system. With such procedures, water draining treatment in the storing and decaying storage vessel is mitigated, and even when the amount of the radioactive iodine-containing liquid wastes is increased, the existent maintaining and decaying storage vessel can be used as it is. Accordingly, a safe water draining treatment with good efficiency can be conducted relative to radioactive iodine-containing liquid wastes at a reduced cost. (T.M.)

Influence of mechanical-biological waste pre-treatment methods on the gas formation in landfills

International Nuclear Information System (INIS)

Bockreis, A.; Steinberg, I.

2005-01-01

In order to minimise emissions and environmental impacts, only pre-treated waste should be disposed of. For the last six years, a series of continuous experiments has been conducted at the Institute WAR, TU Darmstadt, in order to determine the emissions from pre-treated waste. Different kinds of pre-treated waste were incubated in several reactors and various data, including production and composition of the gas and the leachate, were collected. In this paper, the interim results of gas production and the gas composition from different types of waste after a running time of six years are presented and discussed

Particle size distribution in soils and marine sediments by laser diffraction using Malvern Mastersizer 2000—method uncertainty including the effect of hydrogen peroxide pretreatment

DEFF Research Database (Denmark)

Callesen, Ingeborg; Keck, Hannes; Andersen, Thorbjørn Joest

2018-01-01

with less than 1% C and some marine sediments. Materials and methods: The method uncertainty for particle size analysis by the laser diffraction method using or not using H2O2 pretreatment followed by 2 min ultrasound and 1-mm sieving was determined for two soil samples and two aquatic sediments......Purpose: Methods for particle size distribution (PSD) determination by laser diffraction are not standardized and differ between disciplines and sectors. The effect of H2O2 pretreatment before a sonication treatment in laser diffraction analysis of soils and marine sediments was examined on soils...... pretreatment on the PSD was small and not significant. The standard deviation (std) in particle size fractions increased with particle size. PSDs and std for some samples were presented for future reference. Similar to other studies, the content of clay and silt (by sieving/hydrometer, SHM) was lower...

The pretreatment of corn stover with Gloeophyllum trabeum KU-41 for enzymatic hydrolysis

Directory of Open Access Journals (Sweden)

Gao Ziqing

2012-05-01

Full Text Available Abstract Background Pretreatment is an essential step in the enzymatic hydrolysis of biomass for bio-ethanol production. The dominant concern in this step is how to decrease the high cost of pretreatment while achieving a high sugar yield. Fungal pretreatment of biomass was previously reported to be effective, with the advantage of having a low energy requirement and requiring no application of additional chemicals. In this work, Gloeophyllum trabeum KU-41 was chosen for corn stover pretreatment through screening with 40 strains of wood-rot fungi. The objective of the current work is to find out which characteristics of corn stover pretreated with G. trabeum KU-41 determine the pretreatment method to be successful and worthwhile to apply. This will be done by determining the lignin content, structural carbohydrate, cellulose crystallinity, initial adsorption capacity of cellulase and specific surface area of pretreated corn stover. Results The content of xylan in pretreated corn stover was decreased by 43% in comparison to the untreated corn stover. The initial cellulase adsorption capacity and the specific surface area of corn stover pretreated with G. trabeum were increased by 7.0- and 2.5-fold, respectively. Also there was little increase in the cellulose crystallinity of pretreated corn stover. Conclusion G. trabeum has an efficient degradation system, and the results indicated that the conversion of cellulose to glucose increases as the accessibility of cellulose increases due to the partial removal of xylan and the structure breakage of the cell wall. This pretreatment method can be further explored as an alternative to the thermochemical pretreatment method.

Novel dark fermentation involving bioaugmentation with constructed bacterial consortium for enhanced biohydrogen production from pretreated sewage sludge

Energy Technology Data Exchange (ETDEWEB)

Kotay, Shireen Meher; Das, Debabrata [Department of Biotechnology, Indian Institute of Technology, Kharagpur (India)

2009-09-15

The present study summarizes the observations on various nutrient and seed formulation methods using sewage sludge that have been aimed at ameliorating the biohydrogen production potential. Pretreatment methods viz., acid/base treatment, heat treatment, sterilization, freezing-thawing, microwave, ultrasonication and chemical supplementation were attempted on sludge. It was observed that pretreatment was essential not only to reduce the needless, competitive microbial load but also to improve the nutrient solublization of sludge. Heat treatment at 121 C for 20 min was found to be most effective in reducing the microbial load by 98% and hydrolyzing the organic fraction of sludge. However, this pretreatment alone was either not sufficient or inconsistent in developing a suitable microbial consortium for hydrogen production. Hydrogen yield was found to improve 1.5-4 times upon inoculation with H{sub 2}-producing microorganisms. A defined microbial consortium was developed consisting of three established bacteria viz., Enterobacter cloacae IIT-BT 08, Citrobacter freundii IIT-BT L139 and Bacillus coagulans IIT-BT S1. Following pretreatments soluble proteins and lipids (the major component of the sludge) were also found to be consumed besides carbohydrates. This laid out the concurrent proteolytic/lipolytic ability of the developed H{sub 2}-producing consortium. 1:1:1 v/v ratio of these bacteria in consortium was found to give the maximum yield of H{sub 2} from sludge, 39.15 ml H{sub 2}/g COD{sub reduced}. 15%v/v dilution and supplementation with 0.5%w/v cane molasses prior to heat treatment was found to further improve the yield to 41.23 ml H{sub 2}/g COD{sub reduced}. (author)

Rheological Studies on Pretreated Feed and Melter Feed from AW-101 and AN-107

International Nuclear Information System (INIS)

Bredt, Paul R; Swoboda, Robert G

2001-01-01

Rheological and physical properties testing were conducted on actual AN-107 and AW-101 pretreated feed samples prior to the addition of glass formers. Analyses were repeated following the addition of glass formers. The AN-107 and AW-101 pretreated feeds were tested at the target sodium values of nominally 6, 8, and 10 M. The AW-101 melter feeds were tested at these same concentrations, while the AN-107 melter feeds were tested at 5, 6, and 8 M with respect to sodium. These data on actual waste are required to validate and qualify results obtained with simulants

The effectiveness of pretreatment physics plan review for detecting errors in radiation therapy

International Nuclear Information System (INIS)

Gopan, Olga; Zeng, Jing; Novak, Avrey; Nyflot, Matthew; Ford, Eric

2016-01-01

Purpose: The pretreatment physics plan review is a standard tool for ensuring treatment quality. Studies have shown that the majority of errors in radiation oncology originate in treatment planning, which underscores the importance of the pretreatment physics plan review. This quality assurance measure is fundamentally important and central to the safety of patients and the quality of care that they receive. However, little is known about its effectiveness. The purpose of this study was to analyze reported incidents to quantify the effectiveness of the pretreatment physics plan review with the goal of improving it. Methods: This study analyzed 522 potentially severe or critical near-miss events within an institutional incident learning system collected over a three-year period. Of these 522 events, 356 originated at a workflow point that was prior to the pretreatment physics plan review. The remaining 166 events originated after the pretreatment physics plan review and were not considered in the study. The applicable 356 events were classified into one of the three categories: (1) events detected by the pretreatment physics plan review, (2) events not detected but “potentially detectable” by the physics review, and (3) events “not detectable” by the physics review. Potentially detectable events were further classified by which specific checks performed during the pretreatment physics plan review detected or could have detected the event. For these events, the associated specific check was also evaluated as to the possibility of automating that check given current data structures. For comparison, a similar analysis was carried out on 81 events from the international SAFRON radiation oncology incident learning system. Results: Of the 356 applicable events from the institutional database, 180/356 (51%) were detected or could have been detected by the pretreatment physics plan review. Of these events, 125 actually passed through the physics review; however

The effectiveness of pretreatment physics plan review for detecting errors in radiation therapy

Energy Technology Data Exchange (ETDEWEB)

Gopan, Olga; Zeng, Jing; Novak, Avrey; Nyflot, Matthew; Ford, Eric, E-mail: eford@uw.edu [Department of Radiation Oncology, University of Washington Medical Center, 1959 NE Pacific Street, Box 356043, Seattle, Washington 98195 (United States)

2016-09-15

Purpose: The pretreatment physics plan review is a standard tool for ensuring treatment quality. Studies have shown that the majority of errors in radiation oncology originate in treatment planning, which underscores the importance of the pretreatment physics plan review. This quality assurance measure is fundamentally important and central to the safety of patients and the quality of care that they receive. However, little is known about its effectiveness. The purpose of this study was to analyze reported incidents to quantify the effectiveness of the pretreatment physics plan review with the goal of improving it. Methods: This study analyzed 522 potentially severe or critical near-miss events within an institutional incident learning system collected over a three-year period. Of these 522 events, 356 originated at a workflow point that was prior to the pretreatment physics plan review. The remaining 166 events originated after the pretreatment physics plan review and were not considered in the study. The applicable 356 events were classified into one of the three categories: (1) events detected by the pretreatment physics plan review, (2) events not detected but “potentially detectable” by the physics review, and (3) events “not detectable” by the physics review. Potentially detectable events were further classified by which specific checks performed during the pretreatment physics plan review detected or could have detected the event. For these events, the associated specific check was also evaluated as to the possibility of automating that check given current data structures. For comparison, a similar analysis was carried out on 81 events from the international SAFRON radiation oncology incident learning system. Results: Of the 356 applicable events from the institutional database, 180/356 (51%) were detected or could have been detected by the pretreatment physics plan review. Of these events, 125 actually passed through the physics review; however

Enzymatic pretreatment of wood chips for energy reductions in TMP production. A method for ranking of enzymes; Enzymatisk foerbehandling av flis foer energibesparing vid TMP tillverkning. Metod foer rankning av enzymer

Energy Technology Data Exchange (ETDEWEB)

Viforr, Silvia

2010-11-15

The production of thermomechanical pulp (TMP) demands high levels of energy. This, together with current expensive energy prices of nowadays results in significant costs, which is the reason why there is a demand for processes that require less energy. One way of reducing energy consumption in TMP refining could be to pretreat the wood chips with enzymes before the subsequent refining step. However, enzymes molecules are relatively large, which limits the impregnation process, and so the pores in the fibre walls are not large enough to fit the size of the enzymes. By mechanically pretreating wood chips in a screw feeder and press equipment, this opens the wood structure significantly which increases enzyme penetration. If enzymes are used for reducing energy consumption in TMP processes, it is necessary to optimise the enzymatic effect during the pretreatment of wood chips. It is very expensive to evaluate completely the effect of enzymes in large scale refining. Thus there is a need for other relevant methods for rapidly and effectively evaluating the energy saving effects when it comes to refining enzymatic pretreated wood chips. The aim of this project was to find a method for ranking of enzymes for pretreatment of chips for energy savings at TMP production. This method was to be independent of the type of enzyme used and of the type of pretreated wood chips involved. In order to asses the method for ranking enzymes being used in the pretreatment of chips to reduce energy input during refining, a comparison between the method and a mill trial was carried out in the mill trial. A known chemical pretreatment was used; here it was sulphonation of the wood chips before refining with low sulphite levels. Further, a laboratory wing refiner was used as an evaluation equipment. The trial started with the running conditions for a wing refiner that the best correspond with industrial refining. An evaluation was made on the effect of enzymatic pretreatment on energy

The impacts of pretreatment on the fermentability of pretreated lignocellulosic biomass: a comparative evaluation between ammonia fiber expansion and dilute acid pretreatment

Directory of Open Access Journals (Sweden)

Dale Bruce E

2009-12-01

Full Text Available Abstract Background Pretreatment chemistry is of central importance due to its impacts on cellulosic biomass processing and biofuels conversion. Ammonia fiber expansion (AFEX and dilute acid are two promising pretreatments using alkaline and acidic pH that have distinctive differences in pretreatment chemistries. Results Comparative evaluation on these two pretreatments reveal that (i AFEX-pretreated corn stover is significantly more fermentable with respect to cell growth and sugar consumption, (ii both pretreatments can achieve more than 80% of total sugar yield in the enzymatic hydrolysis of washed pretreated solids, and (iii while AFEX completely preserves plant carbohydrates, dilute acid pretreatment at 5% solids loading degrades 13% of xylose to byproducts. Conclusion The selection of pretreatment will determine the biomass-processing configuration, requirements for hydrolysate conditioning (if any and fermentation strategy. Through dilute acid pretreatment, the need for hemicellulase in biomass processing is negligible. AFEX-centered cellulosic technology can alleviate fermentation costs through reducing inoculum size and practically eliminating nutrient costs during bioconversion. However, AFEX requires supplemental xylanases as well as cellulase activity. As for long-term sustainability, AFEX has greater potential to diversify products from a cellulosic biorefinery due to lower levels of inhibitor generation and lignin loss.

Is Inconsistent Pre-treatment Bedtime Related to CPAP Non-Adherence?

Science.gov (United States)

Sawyer, Amy M.; King, Tonya S.; Sawyer, Douglas A.; Rizzo, Albert

2014-01-01

Lack of adherence to continuous positive airway pressure therapy (CPAP) limits the effectiveness of treatment of obstructive sleep apnea (OSA). We hypothesized that an irregular bedtime would be negatively related to regular use of CPAP treatment. If so, modifying bedtime schedule may address the persistent problem of inconsistent CPAP use in adults with OSA. In a prospective longitudinal study, we examined whether inconsistent self-reported bedtime before initiation of CPAP treatment, operationalized as bedtime variability, was (1) different among those adherent (≥ 4 hours per night) and non-adherent to CPAP treatment at one week and one month; and/or (2) was related to one-week and one-month CPAP use when other variables were accounted for. Consecutively-recruited newly-diagnosed OSA adults (N=79) completed sleep diaries prior to CPAP treatment. One-week and one-month objective CPAP use data were collected. Pre-treatment bedtime variability was different among CPAP non-adherers and adherers at one month and was a significant predictor of non-adherence at one month in multivariate analyses. The odds of one-month CPAP non-adherence were 3.5 times greater in those whose pre-treatment bedtimes varied by >75 minutes. Addressing sleep schedule prior to CPAP initiation may be an opportunity to improve CPAP adherence. PMID:25353159

Lung cancer gene expression database analysis incorporating prior knowledge with support vector machine-based classification method

Directory of Open Access Journals (Sweden)

Huang Desheng

2009-07-01

Full Text Available Abstract Background A reliable and precise classification is essential for successful diagnosis and treatment of cancer. Gene expression microarrays have provided the high-throughput platform to discover genomic biomarkers for cancer diagnosis and prognosis. Rational use of the available bioinformation can not only effectively remove or suppress noise in gene chips, but also avoid one-sided results of separate experiment. However, only some studies have been aware of the importance of prior information in cancer classification. Methods Together with the application of support vector machine as the discriminant approach, we proposed one modified method that incorporated prior knowledge into cancer classification based on gene expression data to improve accuracy. A public well-known dataset, Malignant pleural mesothelioma and lung adenocarcinoma gene expression database, was used in this study. Prior knowledge is viewed here as a means of directing the classifier using known lung adenocarcinoma related genes. The procedures were performed by software R 2.80. Results The modified method performed better after incorporating prior knowledge. Accuracy of the modified method improved from 98.86% to 100% in training set and from 98.51% to 99.06% in test set. The standard deviations of the modified method decreased from 0.26% to 0 in training set and from 3.04% to 2.10% in test set. Conclusion The method that incorporates prior knowledge into discriminant analysis could effectively improve the capacity and reduce the impact of noise. This idea may have good future not only in practice but also in methodology.

Evaluation of sample pretreatment methods for analysis of polonium isotopes in herbal medicines

International Nuclear Information System (INIS)

Sreejith, Sathyapriya R.; Nair, Madhu G.; Rao, D.D.

2014-01-01

Herbal infusions like ayurvedic aristas are widely consumed by Indian population for good health. With increasing awareness about radiological assessment, an effort was made to assess the radioactivity concentration of naturally occurring radionuclides in herbal medicines. 210 Po is an important alpha particle emitter contributing to internal dose to man from ingestion. Though 210 Po can be spontaneously deposited on silver disk for alpha spectrometric measurements with less radiochemical step, great care has to be taken during the sample pretreatment step owing to the high volatility of polonium even at low temperatures. Aim of the study was to evaluate an appropriate sample pretreatment method for estimation of polonium in herbal medicines. 209 Po was used for radiochemical yield calculation. Conventional open vessel wet ashing, physical evaporation, freeze-drying and microwave digestion in a Teflon vessel were examined. The recovery ranged between 9 and 79%. The lowest recovery was obtained for the samples that were processed by open vessel digestion without any volume reduction. The recoveries were comparable for those samples that were freeze dried and subjected to HNO 3 + HClO 4 + H 2 O 2 + HF acid digestion and microwave digested samples. 210 Po concentration in the samples ranged from 11.3 to 39.6 mBq/L

Fabrication of indium tin oxide (ITO) thin film with pre-treated sol coating

International Nuclear Information System (INIS)

Hong, Sung-Jei; Han, Jeong-In

2004-01-01

A new pre-treated sol-coating method to fabricate an indium tin oxide (ITO) thin film is introduced in this paper. The pre-treatment sol-coating method is to form a seed layer on the substrate before spin coating of ITO sol. The pre-treatment was carried out at room temperature in order not to damage the substrate during the pre-treatment. It is effective to enhance the formation of the ITO sol film on the substrate, owing to the seed layer. The seed layer consists of ultrafine grains, which are observed at the pre-treated substrate. For the optimal pre-treatment condition, we used pre-treatment times of 24, 48, 72, and 96 hours to observe the effect on the characteristics of ITO sol film. As a result, the lowest resistance could be achieved with a pre-treatment time of 72 hours. The optical transmittance of the ITO sol film with the pre-treatment time of 72 hours exceeded 80 % at a wavelength of 400 nm. So, an ITO sol film with good electrical and optical properties could be fabricated by using the pretreatment sol coating.

A Sequential Combination of Laccase Pretreatment and Enzymatic Hydrolysis for Glucose Production from Furfural Residues

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Hailong Yu

2014-06-01

Full Text Available Furfural residues (FRs were pretreated with laccase or a laccase-mediator (1-hydroxybenzotriazole, HBT system to produce fermentable sugar for bioethanol production. Compared to laccase-only pretreatment, laccase-mediator pretreatment dissolved more lignin. Approximately 10.5% of the initially present lignin was removed when FRs were treated with a laccase loading of 100 U/g of dry substrate in 1% (w/w HBT at 48 °C for 24 h in an acetate buffer (pH 4.8. The enzymatic saccharification process was carried out by a combined laccase or laccase-mediator pretreatment without washing of the treated solids. The results showed that active laccase had a negative effect on the rate and yield of enzymatic hydrolysis. Laccase-oxidized HBT seriously reduced glucose yield. However, non-oxidized HBT increased glucose yield when laccase was deactivated at 121 °C for 20 min prior to enzymatic hydrolysis. The highest glucose yield, 80.9%, was obtained from the substrate pretreated with 100 U/g of dry substrate laccase and 1% (w/w HBT at 48 °C for 24 h in an acetate buffer (pH 4.8. Furthermore, the structures of FRs before and after laccase-mediator pretreatment were characterized by scanning electron microscopy (SEM and Fourier Transform Infrared spectroscopy (FT-IR.

EFFECT OF AQUEOUS PRETREATMENT ON PYROLYSIS CHARACTERISTICS OF NAPIER GRASS

Directory of Open Access Journals (Sweden)

ISAH YAKUB MOHAMMED

2015-11-01

Full Text Available Effect of non-catalytic aqueous pretretment on pyrolysis characteristics of Napier grass was investigated using thermogravimetric analyser. Increasing pretreatment severity (0.0-2.0 improved pyrolysis process. The residual mass at the end of pyrolysis for the pretreated sample was about 50% less compared to the untreated sample. Kinetics of the process was evaluated using order based model and both pretreated and untreated samples followed first order reaction. The activation energy of the pretreated samples was similar and higher than that of the raw sample which was attributed to faster rate of decomposition due removal of hetromaterials (ash, extractives and some hemicellulose in the pretreatment stage. Finally, this pretreatment method has demonstrated effectiveness for the removal of pyrolysis retardants and will improve the quantity and quality of bio-oil yield.

Extrusion Pretreatment of Lignocellulosic Biomass: A Review

Directory of Open Access Journals (Sweden)

Jun Zheng

2014-10-01

Full Text Available Bioconversion of lignocellulosic biomass to bioethanol has shown environmental, economic and energetic advantages in comparison to bioethanol produced from sugar or starch. However, the pretreatment process for increasing the enzymatic accessibility and improving the digestibility of cellulose is hindered by many physical-chemical, structural and compositional factors, which make these materials difficult to be used as feedstocks for ethanol production. A wide range of pretreatment methods has been developed to alter or remove structural and compositional impediments to (enzymatic hydrolysis over the last few decades; however, only a few of them can be used at commercial scale due to economic feasibility. This paper will give an overview of extrusion pretreatment for bioethanol production with a special focus on twin-screw extruders. An economic assessment of this pretreatment is also discussed to determine its feasibility for future industrial cellulosic ethanol plant designs.

Use of alkaline or enzymatic sample pretreatment prior to characterization of gold nanoparticles in animal tissue by single-particle ICPMS

DEFF Research Database (Denmark)

Löschner, Katrin; Brabrand, Myung Suk Jung; Sloth, Jens Jørgen

2014-01-01

, not much is known about the applicability of spICPMS for determination of NPs in complex matrices such as biological tissues. In the present study, alkaline and enzymatic treatments were applied to solubilize spleen samples from rats, which had been administered 60-nm gold nanoparticles (Au......NPs) intravenously. The results showed that similar size distributions of AuNPs were obtained independent of the sample preparation method used. Furthermore, the quantitative results for AuNP mass concentration obtained with spICPMS following alkaline sample pretreatment coincided with results for total gold...... concentration obtained by conventional ICPMS analysis of acid-digested tissue. The recovery of AuNPs from enzymatically digested tissue, however, was approximately four times lower. Spiking experiments of blank spleen samples with AuNPs showed that the lower recovery was caused by an inferior transport...

A Frequency Matching Method: Solving Inverse Problems by Use of Geologically Realistic Prior Information

DEFF Research Database (Denmark)

Lange, Katrine; Frydendall, Jan; Cordua, Knud Skou

2012-01-01

The frequency matching method defines a closed form expression for a complex prior that quantifies the higher order statistics of a proposed solution model to an inverse problem. While existing solution methods to inverse problems are capable of sampling the solution space while taking into account...... arbitrarily complex a priori information defined by sample algorithms, it is not possible to directly compute the maximum a posteriori model, as the prior probability of a solution model cannot be expressed. We demonstrate how the frequency matching method enables us to compute the maximum a posteriori...... solution model to an inverse problem by using a priori information based on multiple point statistics learned from training images. We demonstrate the applicability of the suggested method on a synthetic tomographic crosshole inverse problem....

Pretreatment of macroalgae for volatile fatty acid production.

Science.gov (United States)

Pham, Thi Nhan; Um, Youngsoon; Yoon, Hyon Hee

2013-10-01

In this study, a novel method was proposed for the biological pretreatment of macroalgae (Laminaria japonica, Pachymeniopsis elliptica, and Enteromorpha crinita) for production of volatile fatty acid (VFA) by anaerobic fermentation. The amount of VFA produced from 40 g/L of L. japonica increased from 8.3 g/L (control) to 15.6 g/L when it was biologically pretreated with Vibrio harveyi. The biological treatment of L. japonica with Vibrio spp. was most effective likely due to the alginate lyase activity of Vibrio spp. However, a considerable effect was also observed after biological pretreatment of P. elliptica and E. crinita, which are red and green algae, respectively. Alkaline pretreatment of 40 g/L of L. japonica with 0.5 N NaOH resulted in an increase of VFA production to 12.2 g/L. These results indicate that VFA production from macroalgae can be significantly enhanced using the proposed biological pretreatments. Copyright © 2013 Elsevier Ltd. All rights reserved.

TiO_2 assisted photo-oxidation of wastewater prior to voltammetric determination of trace metals: Eco-friendly alternative to traditional digestion methods

International Nuclear Information System (INIS)

Lejbt, Beata; Ospina-Alvarez, Natalia; Miecznikowski, Krzysztof; Krasnodębska-Ostręga, Beata

2016-01-01

Highlights: • Cheap and eco-friendly method using anatase-assisted photodecomposition to pre-treat wastewater samples prior to trace metal analysis. • Addition of polyvinylidene fluoride did not affect the efficiency of organic matter decomposition. • TiO_2 assisted photo-oxidation procedure is equally effective than ICP MS determination after UV assisted digestion with H_2O_2 addition. - Abstract: Voltammetry is a sensitive method for metal determination and one alternative to ICP MS, but its limitation is the influence of the organic matrix on the measurements. To avoid those interferences, wet digestion with H_2O_2 accelerated with UV irradiation is applied and evaporation of excess of reagents is required. In this study, photolytic oxidation in quartz tubes with anatase was carried out, using as object of study wastewater samples with high amount of organic matter. Cadmium and lead determination was carried out in order to test metal recoveries. Lead recoveries reached c.a 85% for UV digestion with hydrogen peroxide, 98% for digestion with anatase immobilized with polyvinylidene fluoride (N-metylo-2-pirolidon) and c.a 103% for digestion with immobilized anatase (anatase in gum). The results obtained showed the usefulness of TiO_2 layer as an oxidation medium. An easy, cheap and eco-friendly digestion method of surfactants without any reagent has been developed, with equal sensitivity but and the same detection limit of traditional digestion methods.

Influence of Adhesives and Methods of Enamel Pretreatment on the Shear Bond Strength of Orthodontic Brackets.

Science.gov (United States)

Jurišić, Sanja; Jurišić, Gordan; Jurić, Hrvoje

2015-12-01

The objective of present study was to examine influence of adhesives and methods of enamel pretreatment on the shear bond strength (SBS) of orthodontic brackets. The adhesives used were resin-reinforced glass ionomer cements-GIC (Fuji Ortho LC) and composite resin (Transbond XT). The experimental sample consisted of 80 extracted human first premolars. The sample was divided into four equal groups, and the metal brackets were bonded with different enamel pretreatments by using two adhesives: group A-10% polyacrylic acid; Fuji Ortho LC, group B-37% phosphoric acid; Fuji Ortho LC, group C-self etching primer; Transbond XT, group D-37% phosphoric acid, primer; Transbond XT. SBS of brackets was measured. After debonding of brackets, the adhesive remnant index (ARI) was evaluated. After the statistical analysis of the collected data was performed (ANOVA; Sheffe post-hoc test), the results showed that significantly lower SBS of the group B was found in relation to the groups C (p=0.031) and D (p=0.026). The results of ARI were similar in all testing groups and it was not possible to determine any statistically significant difference of the ARI (Chi- square test) between all four experimental groups. The conclusion is that the use of composite resins material with appropriate enamel pretreatment according to manufacturer's recommendation is the "gold standard" for brackets bonding for fixed orthodontic appliances.

Dielectric barrier discharge plasma pretreatment on hydrolysis of microcrystalline cellulose

Science.gov (United States)

Huang, Fangmin; Long, Zhouyang; Liu, Sa; Qin, Zhenglong

2017-04-01

Dielectric barrier discharge (DBD) plasma was used as a pretreatment method for downstream hydrolysis of microcrystalline cellulose (MCC). The degree of polymerization (DP) of MCC decreased after it was pretreated by DBD plasma under a carrier gas of air/argon. The effectiveness of depolymerization was found to be influenced by the crystallinity of MCC when under the pretreatment of DBD plasma. With the addition of tert-butyl alcohol in the treated MCC water suspension solution, depolymerization effectiveness of MCC was inhibited. When MCC was pretreated by DBD plasma for 30 min, the total reducing sugar concentration (TRSC) and liquefaction yield (LY) of pretreated-MCC (PMCC) increased by 82.98% and 34.18% respectively compared with those for raw MCC.

The utilisation of virtual images in patient information giving sessions for prostate cancer patients prior to radiotherapy

International Nuclear Information System (INIS)

Stewart-Lord, A.; Brown, M.; Noor, S.; Cook, J.; Jallow, O.

2016-01-01

The aim of the study was to explore the prostate patients' perceptions of a Virtual Environment for Radiotherapy Training (VERT) as an information giving resource prior to radiotherapy delivery. A survey design was used to determine the level of knowledge of those patients who attended VERT for a pre-treatment talk and identify the benefits and limitations of using VERT as pre-treatment information giving resource. Participants were invited to attend a VERT patient information session four weeks prior to their planning CT scan, and then complete a questionnaire two weeks after start of radiotherapy treatment. A sample of n = 38 patients were recruited over a five month data collection period. Results showed that patient perceptions on the use of VERT as information giving tool prior to radiotherapy treatment were very positive. The sessions enable patients to understand the potential impact of treatment volumes if the internal organ shape and location differed from that originally planned, enabling them to comply with radiotherapy treatment instructions. Additional key findings have demonstrated excellent levels of communication associated with the use of VERT emphasising the need for future patient preparation strategies to consider the use of virtual technology. - Highlights: • VERT pre-treatment information sessions were very helpful to patients. • Patients had a better understanding of what to expect during treatment. • The importance of following bowel and bladder treatment preparation was made clear. • The session helped to reduced patient anxiety and stress associated with treatment.

Pretreatment and hydrolysis methods for recovery of fermentable sugars from de-oiled Jatropha waste.

Science.gov (United States)

Kumar, Gopalakrishnan; Sen, Biswarup; Lin, Chiu-Yue

2013-10-01

The release of reducing sugars (RS) upon various pretreatments and hydrolysis methods from de-oiled Jatropha waste (DJW) was studied. The highest RS concentration of 12.9 g/L was observed at 10% enzyme hydrolysis. The next highest RS of 8.0 g/L and 7.8 g/L were obtained with 10% HCl and 2.5% H2SO4, respectively. The NaOH (2.5%), ultrasonication and heat (90°C for 60 min) treatments showed the RS concentration of 2.5 g/L, 1.1 g/L and 2.0 g/L, respectively. Autoclave treatment slightly enhanced the sugar release (0.9 g/L) compared to no treatment (0.7 g/L). Glucose release (11.4 g/L) peaked in enzyme hydrolysis. Enzyme treated acid unhydrolysed biomass showed 11.1 g/L RS. HCl and H2SO4 pretreatment gave maximal xylose (6.89 g/L and 6.16 g/L, respectively). Combined (acid and enzyme) hydrolysis employed was efficient and its subsequent batch hydrogen fermentation showed a production 3.1 L H2/L reactor. Copyright © 2013 Elsevier Ltd. All rights reserved.

Enhancement of biogas production in anaerobic co-digestion by ultrasonic pretreatment

International Nuclear Information System (INIS)

Zou, Shuzhen; Wang, Xiaojiao; Chen, Yuanlin; Wan, Haiwen; Feng, Yongzhong

2016-01-01

Highlights: • Ultrasonic pretreatment changed physical structure of samples. • Ultrasonic pretreatment improved biogas production via changing environment before and during anaerobic digestion process. • The main factors affecting biogas production differ in different pretreated samples. - Abstract: This paper optimized the anaerobic digestion (AD) pretreatment process and identified the influence of pretreatment on the co-digestion of maize straw (MS) and dairy manure (DM). In the study, ultrasonic was used to pretreat MS and DM prior to digestion, with power intensities of 0, 189.39, 284.09, and 378.79 kJ at 0, 20, 30, and 40 min, respectively. Changes in the surface structures of MS and DM were observed by scanning electron microscopy (SEM), and factor analysis was used to analyze the main factors affecting biogas production in the AD process. The result showed that the structure of DM was distributed and that the structure of MS became more roughness following the ultrasonic pretreatment (UP). The highest total biogas production of co-digestion (240.32 mL/g VS_f_e_d) was obtained when MS was pretreated for 30 min without DM pretreatment (MS_3_0DM_0). This was significantly higher than that of the untreated sample (CK) (141.65 mL/g VS_f_e_d). The cellulose activity (CA), reducing sugar (RS) content, volatile fatty acid (VFA) content and pH in the digester feed, and their maximum and minimum values in the AD process was affected by UP. Factor 1 of MS_3_0DM_0 was determined by RS content, pH and VFA content that they had the most influence on biogas production on days 6, 18, 24 and 30. Factor 2 of it was determined by CA, and it had most influence on days 0, 12, 36 and 42 in the AD process, The result of the factor analysis indicated that the main factors affecting biogas production were affected by UP and they differ according to the different digestion stages. This research concluded that UP improved total biogas production via changing the initial

Screening and optimization of pretreatments for Parthenium hysterophorus as feedstock for alcoholic biofuels

International Nuclear Information System (INIS)

Singh, Shuchi; Khanna, Swati; Moholkar, Vijayanand S.; Goyal, Arun

2014-01-01

Highlights: • Optimization of pretreatment methods for Parthenium hysterophorus for bioalcohol production. • Physical, chemical and physicochemical pretreatments methods employed. • Most efficient treatment: autoclaving 121 °C, 15 psi for 30 min in 1% H 2 SO 4 solution. • TFS (total fermentable sugar) yield after pretreatment and enzymatic hydrolysis = 397.7 mg/g raw biomass. • Parthenium hysterophorus is at par with agro- and forest residues as biofuels feedstock. - Abstract: Parthenium hysterophorus world’s seven most devastating and hazardous weeds, and is abundantly available in several parts of the world. This study treats the subject of effective utilization of this waste biomass (which has cellulose content of 45.2 ± 1.81% w/w) for biofuels production. We have presented a comprehensive and comparative assessment of numerous pretreatment strategies for P. hysterophorus, comprising of all major physical, chemical and physicochemical methods. The yardstick of assessment has been amount of fermentable sugars released during the pretreatment and the post-treatment enzymatic hydrolysis of pretreated biomass. Carboxymethylcellulase (1.0 U/mg, 1.7 mg/mL) produced by an isolate Bacillus amyloliquefaciens SS35 and β-glucosidase (Novozyme 188), have been used for enzymatic hydrolysis of pretreated biomass. Among the different methods employed for pretreatment, the most efficient treatment has been revealed to be autoclaving of biomass at 121 °C and 15 psi pressure for 30 min in acidic (1% v/v, H 2 SO 4 ) environment. Total reducing sugar (TRS) yield during this pretreatment, mainly due to hydrolysis of hemicellulosic fraction of biomass, has been 285.3 mg/g of raw biomass. Further enzymatic hydrolysis resulted in reducing sugar yield of 187.4 mg/g of pretreated biomass (9.37 g/L). The total fermentable sugar (TFS) yield from the optimized pretreatment was 397.7 mg/g raw biomass (39.77 g/100 g raw biomass). The effects of different pretreatment methods

Comparison of Different Pretreatment Strategies for Ethanol Production of West African Biomass

DEFF Research Database (Denmark)

Thomsen, Sune Tjalfe; Gonzalez Londono, Jorge Enrique; Schmidt, Jens Ejbye

2015-01-01

husks, cocoa pods, maize cobs, maize stalks, rice straw, groundnut straw and oil palm empty fruit bunches. It was found that four biomass’ (plantain peelings, plantain trunks, maize cobs and maize stalks) were most promising for production of cellulosic ethanol with profitable enzymatic conversion......Pretreating lignocellulosic biomass for cellulosic ethanol production in a West African setting requires smaller scale and less capital expenditure compared to current state of the art. In the present study, three low-tech methods applicable for West African conditions, namely Boiling Pretreatment...... (BP), Soaking in Aqueous Ammonia (SAA) and White Rot Fungi pretreatment (WRF), were compared to the high-tech solution of hydrothermal pretreatment (HTT). The pretreatment methods were tested on 11 West African biomasses, i.e. cassava stalks, plantain peelings, plantain trunks, plantain leaves, cocoa...

Effect of oxalic acid pretreatment of wood chips on manufacturing medium-density fiberboard

Science.gov (United States)

Xianjun Li; Zhiyong Cai; Eric Horn; Jerrold E. Winandy

2011-01-01

The main objective of this study was to evaluate the effect of oxalic acid (OA) wood chips pretreatment prior to refining, which is done to reduce energy used during the refining process. Selected mechanical and physical performances of medium-density fiberboard (MDF) – internal bonding (IB), modulus of elasticity (MOE), modulus of rupture (MOR), water absorption (WA)...

Ethanol from softwood. Process development based on steam pretreatment and SSF

Energy Technology Data Exchange (ETDEWEB)

Stenberg, Kerstin

1999-05-01

Fuel ethanol can be produced from lignocellulosics by the enzymatic hydrolysis process, which consists of a pretreatment step prior to hydrolysis, followed by fermentation and finally refining. This thesis deals with the development of the enzymatic process using softwood as raw material. The focus has not only been on how to obtain high yields, but also on how to solve problems, which can arise in an industrial process, such as inhibition and contamination. The pretreatment step was evaluated using steam-pretreatment and impregnation with an acid catalyst, either SO{sub 2} or H{sub 2}SO{sub 4}. Both impregnation methods resulted in approximately the same yield, 65% of the theoretical of fermentable sugars, i.e. glucose and mannose, after enzymatic hydrolysis. However, impregnation with SO{sub 2}, resulted in higher ethanol productivity and yield in the fermentation. Simultaneous saccharification and fermentation (SSF) was investigated using various substrate and cellulase concentrations. An overall ethanol yield of 70% of the theoretical was obtained using the whole slurry from the pretreatment step at an insoluble dry weight content of 5%, which was shown to be optimal. SSF resulted in both higher productivity and higher ethanol yield than in separate hydrolysis and fermentation, but proved to be more sensitive to infection by lactic aid bacteria. More complex process integration, in the form of recirculation of process streams, which is desirable in an industrial process, was investigated using bench-scale equipment. A reduction in the fresh-water demand of 50%, from 3 kg/kg dry raw material to 1.5 kg/kg dry raw material, was found to be possible without any negative effects on either hydrolysis or fermentation. A techno-economic evaluation of different process configurations in a process applying SSF was also performed. It was found that the ethanol production cost could be reduced by 20% by internal energy integration and by another 15% by recirculation to the

Pretreatment of Lignocellulosic Wastes to Improve Ethanol and Biogas Production: A Review

Directory of Open Access Journals (Sweden)

Keikhosro Karimi

2008-09-01

Full Text Available Lignocelluloses are often a major or sometimes the sole components of different waste streams from various industries, forestry, agriculture and municipalities. Hydrolysis of these materials is the first step for either digestion to biogas (methane or fermentation to ethanol. However, enzymatic hydrolysis of lignocelluloses with no pretreatment is usually not so effective because of high stability of the materials to enzymatic or bacterial attacks. The present work is dedicated to reviewing the methods that have been studied for pretreatment of lignocellulosic wastes for conversion to ethanol or biogas. Effective parameters in pretreatment of lignocelluloses, such as crystallinity, accessible surface area, and protection by lignin and hemicellulose are described first. Then, several pretreatment methods are discussed and their effects on improvement in ethanol and/or biogas production are described. They include milling, irradiation, microwave, steam explosion, ammonia fiber explosion (AFEX, supercritical CO2 and its explosion, alkaline hydrolysis, liquid hot-water pretreatment, organosolv processes, wet oxidation, ozonolysis, dilute- and concentrated-acid hydrolyses, and biological pretreatments.

In vacuo substrate pretreatments for enhancing nanodiamond formation in electron cyclotron resonance plasma

International Nuclear Information System (INIS)

Teii, Kungen; Kouzuma, Yutaka; Uchino, Kiichiro

2006-01-01

Substrate pretreatment conditions at low pressures have been examined for enhancing nanocrystalline diamond formation on silicon in electron cyclotron resonance (ECR) plasma. Three kinds of pretreatments (I) exposure to an ECR H 2 plasma with application of a substrate bias from -100 to +30 V (II) hot-filament heating in H 2 gas, and (III) hot-filament heating in vacuum, were used alone or followed by carburization prior to a two-step process of ion-enhanced nucleation in an ECR plasma and subsequent growth in a hot-filament system. The number density of diamond particles after the final growth step was greatly increased up to the order of 10 7 -10 8 cm -2 when applying pretreatment (I) at the bias of 0 V corresponding to the ion-bombardment energy of around 10 eV. In this treatment, a clean and smooth surface with minimal damage was made by the dominance of anisotropic etching by hydrogen ions over isotropic etching by hydrogen atoms. The number density of diamond particles was still more increased when applying pretreatment (II), but the treated surface was unfavorably contaminated and roughened

Removal of Water-Soluble Extractives Improves the Enzymatic Digestibility of Steam-Pretreated Softwood Barks.

Science.gov (United States)

Frankó, Balázs; Carlqvist, Karin; Galbe, Mats; Lidén, Gunnar; Wallberg, Ola

2018-02-01

Softwood bark contains a large amounts of extractives-i.e., soluble lipophilic (such as resin acids) and hydrophilic components (phenolic compounds, stilbenes). The effects of the partial removal of water-soluble extractives before acid-catalyzed steam pretreatment on enzymatic digestibility were assessed for two softwood barks-Norway spruce and Scots pine. A simple hot water extraction step removed more than half of the water-soluble extractives from the barks, which improved the enzymatic digestibility of both steam-pretreated materials. This effect was more pronounced for the spruce than the pine bark, as evidenced by the 30 and 11% glucose yield improvement, respectively, in the enzymatic digestibility. Furthermore, analysis of the chemical composition showed that the acid-insoluble lignin content of the pretreated materials decreased when water-soluble extractives were removed prior to steam pretreatment. This can be explained by a decreased formation of water-insoluble "pseudo-lignin" from water-soluble bark phenolics during the acid-catalyzed pretreatment, which otherwise results in distorted lignin analysis and may also contribute to the impaired enzymatic digestibility of the barks. Thus, this study advocates the removal of extractives as the first step in the processing of bark or bark-rich materials in a sugar platform biorefinery.

Changes in lignocellulosic supramolecular and ultrastructure during dilute acid pretreatment of Populus and switchgrass

International Nuclear Information System (INIS)

Foston, Marcus; Ragauskas, Art J.

2010-01-01

Dilute acid pretreatment (DAP) is commonly employed prior to enzymatic deconstruction of cellulose to increase overall sugar and subsequent ethanol yields from downstream bioconversion processes. Typically optimization of pretreatment is evaluated by determining hemicellulose removal, subsequent reactivity towards enzymatic deconstruction, and recoverable polysaccharide yields. In this study, the affect of DAP on the supramolecular and ultrastructure of lignocellulosic biomass was evaluated. A series of dilute acidic pretreatments, employing ∼0.10-0.20 mol/m 3 H 2 SO 4 at ∼160-180 o C, for varying residence times were conducted on both Populus and switchgrass samples. The untreated and pretreated biomass samples were characterized by carbohydrate and lignin analysis, gel permeation chromatography (GPC) and 13 C cross polarization magic angle spinning (CPMAS) NMR spectroscopy. GPC analysis shows a reduction in the molecular weight of cellulose and change in its polydispersity index (PDI) with increasing residence time, indicating that pretreatment is actually degrading the cellulose chains. 13 C CPMAS and non-linear line-fitting of the C 4 region in the carbon spectrum of the isolated cellulose not only showed that the crystallinity index increases with residence time, but that the lateral fibril dimension (LFD) and lateral fibril aggregate dimension (LFAD) increase as well.

Influence of wheat type and pretreatment on fungal growth in solid-state fermentation

NARCIS (Netherlands)

Hoogschagen, M.; Zhu, Y.; As, H. van; Tramper, J.; Rinzema, A.

2001-01-01

The respiration kinetics of Aspergillus oryzae on different varieties of whole wheat kernels were studied. Six wheat varieties were pretreated in two different ways. Five of the six substrates fermented similarly and independently of the pretreatment method. However, pretreatment affected

Evaluation of sample pretreatment methods for analysis of Polonium isotopes in herbal medicine

International Nuclear Information System (INIS)

Sathyapriya, R.S.; Nair, Madhu G.; Rao, D.D.

2013-01-01

Ayurvedic medicines are widely consumed by Indian population both for treatment and good health Ayurvedic medicines are used in various forms like infusions, decoctions, powder, tablets, fermented decoction (Arishta) etc. Arishtas are prepared using plant extracts soaked in sugar or jaggery and are generally consume on regular basis for good health. Hence an effort was made to analyse the natural radioactivity in the Ayurvedic Arishtas. 213 Po is an important naturally occurring radionuclide that volatilizes beyond 150℃. Hence adequate care is needed during sample pretreatment step. Both physical (freeze-drying, open vessel evaporation and microwave digestion) and chemical (digestion using various mineral acids like aqua regia, Con. HNO 3 , H 2 SO 4 and oxidizing agents like H 2 O 2 and HClO 4 ) pretreatment procedures were adopted. After the initial sample treatment polonium radionuclide was pre-concentrated using calcium phosphate co-precipitation. Calcium phosphate precipitate was dissolved in 150 ml of 0.5M HCI solution with approximately 1 g of ascorbic acid for auto deposition of Polonium on silver planchette for 3 hours at 90℃ on a rotary hot plate. The sample sources were counted in calibrated alpha spectrometer with 450 mm 2 low-back-ground PIPS detector interfaced with ECIL MCA. The spectrum analysis was done using PHAST Software. 209 Po tracer, at low levels was added to the samples for assessing the radiochemical recovery. The recovery ranged between 18-83 %. The lowest recovery was obtained for the samples that were processed by open vessel digestion with HNO 3 + HCIO 4 + H 2 O 2 . The highest recover was for those samples that were freeze dried and subjected to HNO 3 + HCIO 4 + H 2 O 2 acid digestion at 90℃ for 8 hours. 210 Po concentration in a few samples varied between 0.3-3.5 mBq/L. The paper presents the results of radiochemical recoveries for different pretreatment methods and also the 210 Po content in the ayurvedic arishtas. (author)

Biomass pretreatment affects Ustilago maydis in producing itaconic acid

Directory of Open Access Journals (Sweden)

Klement Tobias

2012-04-01

Full Text Available Abstract Background In the last years, the biotechnological production of platform chemicals for fuel components has become a major focus of interest. Although ligno-cellulosic material is considered as suitable feedstock, the almost inevitable pretreatment of this recalcitrant material may interfere with the subsequent fermentation steps. In this study, the fungus Ustilago maydis was used to produce itaconic acid as platform chemical for the synthesis of potential biofuels such as 3-methyltetrahydrofuran. No studies, however, have investigated how pretreatment of ligno-cellulosic biomass precisely influences the subsequent fermentation by U. maydis. Thus, this current study aims to first characterize U. maydis in shake flasks and then to evaluate the influence of three exemplary pretreatment methods on the cultivation and itaconic acid production of this fungus. Cellulose enzymatically hydrolysed in seawater and salt-assisted organic-acid catalysed cellulose were investigated as substrates. Lastly, hydrolysed hemicellulose from fractionated beech wood was applied as substrate. Results U. maydis was characterized on shake flask level regarding its itaconic acid production on glucose. Nitrogen limitation was shown to be a crucial condition for the production of itaconic acid. For itaconic acid concentrations above 25 g/L, a significant product inhibition was observed. Performing experiments that simulated influences of possible pretreatment methods, U. maydis was only slightly affected by high osmolarities up to 3.5 osmol/L as well as of 0.1 M oxalic acid. The production of itaconic acid was achieved on pretreated cellulose in seawater and on the hydrolysed hemicellulosic fraction of pretreated beech wood. Conclusion The fungus U. maydis is a promising producer of itaconic acid, since it grows as single cells (yeast-like in submerged cultivations and it is extremely robust in high osmotic media and real seawater. Moreover, U. maydis can grow on

Enhanced fermentable sugar production from kitchen waste using various pretreatments.

Science.gov (United States)

Hafid, Halimatun Saadiah; Rahman, Nor'Aini Abdul; Md Shah, Umi Kalsom; Baharudin, Azhari Samsu

2015-06-01

The kitchen waste fraction in municipal solid waste contains high organic matter particularly carbohydrate that can contribute to fermentable sugar production for subsequent conversion to bioethanol. This study was carried out to evaluate the influence of single and combination pretreatments of kitchen waste by liquid hot water, mild acid pretreatment of hydrochloric acid (HCl) and sulphuric acid (H2SO4) and enzymatic hydrolysis (glucoamylase). The maximum total fermentable sugar produced after combination pretreatment by 1.5% HCl and glucoamylase consisted of 93.25 g/L glucose, 0.542 g/L sucrose, 0.348 g/L maltose, and 0.321 g/L fructose. The glucose released by the combination pretreatment method was 0.79 g glucose/g KW equivalent to 79% of glucose conversion. The effects of the pre-treatment on kitchen waste indicated that the highest solubilization was 40% by the combination method of 1.5% HCl and glucoamylase. The best combination pre-treatment gave concentrations of lactic acid, acetic acid, and propionic acid of 11.74 g/L, 6.77 g/L, and 1.02 g/L, respectively. The decrease of aliphatic absorbance bands of polysaccharides at 2851 and 2923 cm(-1) and the increase on structures of carbonyl absorbance bands at 1600 cm(-1) reflects the progress of the kitchen waste hydrolysis to fermentable sugars. Overall, 1.5% HCl and glucoamylase treatment was the most profitable process as the minimum selling price of glucose was USD 0.101/g kitchen waste. Therefore, the combination pretreatment method was proposed to enhance the production of fermentable sugar, particularly glucose from kitchen waste as the feedstock for bioethanol production. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Effect of Ultrasound Pretreatment on Poplar Wood Dimensional Stability

Directory of Open Access Journals (Sweden)

Shu Qiu

2016-08-01

Full Text Available Dimensional stability is a key property of wood that significantly affects its applications. The effect of an ultrasound pretreatment on poplar wood (Populous tomentosa dimensional stability was examined. During the pretreatments, wood samples were immersed in distilled water and treated ultrasonically under three different powers and frequencies. The samples were then analyzed by Fourier transform infrared spectroscopy (FTIR and X-ray diffraction (XRD. The chemical transformation of the cell-wall material was studied and then associated with the change of water absorption and the swelling coefficient. The results showed that the water absorption decreased after the ultrasonic pretreatment. The axial and radial swelling coefficients of the pretreated samples decreased, while the tangential swelling coefficients increased. The volumetric swelling coefficient of pretreated specimens fluctuated near 4.48% (the volumetric swelling coefficient of untreated wood. Ultrasonic pretreatment increased the number of hydrophilic groups, such as the hydroxyl, acetyl, and uronic ester groups. Meanwhile, the pretreatment also increased the degree of crystallinity and reduced the available polar groups. These two factors together caused the change of the moisture absorption and the swelling coefficient of the pretreated wood. These conclusions suggest that the ultrasonic pretreatment is a promising method for further chemical modification of wood.

TiO{sub 2} assisted photo-oxidation of wastewater prior to voltammetric determination of trace metals: Eco-friendly alternative to traditional digestion methods

Energy Technology Data Exchange (ETDEWEB)

Lejbt, Beata; Ospina-Alvarez, Natalia; Miecznikowski, Krzysztof, E-mail: kmiecz@chem.uw.edu.pl; Krasnodębska-Ostręga, Beata, E-mail: bekras@chem.uw.edu.pl

2016-12-01

Highlights: • Cheap and eco-friendly method using anatase-assisted photodecomposition to pre-treat wastewater samples prior to trace metal analysis. • Addition of polyvinylidene fluoride did not affect the efficiency of organic matter decomposition. • TiO{sub 2} assisted photo-oxidation procedure is equally effective than ICP MS determination after UV assisted digestion with H{sub 2}O{sub 2} addition. - Abstract: Voltammetry is a sensitive method for metal determination and one alternative to ICP MS, but its limitation is the influence of the organic matrix on the measurements. To avoid those interferences, wet digestion with H{sub 2}O{sub 2} accelerated with UV irradiation is applied and evaporation of excess of reagents is required. In this study, photolytic oxidation in quartz tubes with anatase was carried out, using as object of study wastewater samples with high amount of organic matter. Cadmium and lead determination was carried out in order to test metal recoveries. Lead recoveries reached c.a 85% for UV digestion with hydrogen peroxide, 98% for digestion with anatase immobilized with polyvinylidene fluoride (N-metylo-2-pirolidon) and c.a 103% for digestion with immobilized anatase (anatase in gum). The results obtained showed the usefulness of TiO{sub 2} layer as an oxidation medium. An easy, cheap and eco-friendly digestion method of surfactants without any reagent has been developed, with equal sensitivity but and the same detection limit of traditional digestion methods.

Municipal Solid Waste: Pre-Treatment Options and Benefits on Landfill Emissions

OpenAIRE

Bakare Babatunde Femi

2011-01-01

Municipal solid waste (MSW) comprises of a wide range of heterogeneous materials generated by individual, household or organization and may include food waste, garden wastes, papers, textiles, rubbers, plastics, glass, ceramics, metals, wood wastes, construction wastes but it is not limited to the above mentioned fractions. The most common Municipal Solid Waste pretreatment method in use is thermal pretreatment (incineration) and Mechanical Biological pretreatment. This p...

Effects of enzymatic hydrolysis and ultrasounds pretreatments on corn cob and vine trimming shoots for biogas production.

Science.gov (United States)

Pérez-Rodríguez, N; García-Bernet, D; Domínguez, J M

2016-12-01

Due to their lignocellulosic nature, corn cob and vine trimming shoots (VTS) could be valorized by anaerobic digestion for biogas production. To enhance the digestibility of substrates, pretreatments of lignocellulosic materials are recommended. The effect of enzymatic hydrolysis, ultrasounds pretreatments (US) and the combination of both was assayed in lignocellulosic composition, methane, and biogas yields. The pretreatments leaded to a reduction in lignin and an increase in neutral detergent soluble compounds making corn cob and VTS more amendable for biogas conversion. The US were negative for biogas production from both substrates and in particular strongly detrimental for VTS. On the opposite side, the enzymatic hydrolysis was certainly beneficial increasing 59.8% and 14.6% the methane production from VTS and corn cob, respectively. The prior application of US did not potentiate (or not sufficiently) the improvement in the methane production reflected by the enzymatic hydrolysis pretreatment of VTS and corn cob. Copyright © 2016 Elsevier Ltd. All rights reserved.

Biogas Production from Citrus Wastes and Chicken Feather: Pretreatment and Codigestion

Energy Technology Data Exchange (ETDEWEB)

Forgacs, Gergely

2012-07-01

Anaerobic digestion is a sustainable and economically feasible waste management technology, which lowers the emission of greenhouse gases (GHGs), decreases the soil and water pollution, and reduces the dependence on fossil fuels. The present thesis investigates the anaerobic digestion of waste from food-processing industries, including citrus wastes (CWs) from juice processing and chicken feather from poultry slaughterhouses. Juice processing industries generate 15-25 million tons of citrus wastes every year. Utilization of CWs is not yet resolved, since drying or incineration processes are costly, due to the high moisture content; and biological processes are hindered by its peel oil content, primarily the D-limonene. Anaerobic digestion of untreated CWs consequently results in process failure because of the inhibiting effect of the produced and accumulated VFAs. The current thesis involves the development of a steam explosion pretreatment step. The methane yield increased by 426 % to 0.537 Nm{sup 3}/kg VS by employing the steam explosion treatment at 150 deg C for 20 min, which opened up the compact structure of the CWs and removed 94 % of the D-limonene. The developed process enables a production of 104 m{sup 3} methane and 8.4 L limonene from one ton of fresh CWs. Poultry slaughterhouses generate a significant amount of feather every year. Feathers are basically composed of keratin, an extremely strong and resistible structural protein. Methane yield from feather is low, around 0.18 Nm{sup 3}/kg VS, which corresponds to only one third of the theoretical yield. In the present study, chemical, enzymatic and biological pretreatment methods were investigated to improve the biogas yield of feather waste. Chemical pretreatment with Ca(OH){sub 2} under relatively mild conditions (0.1 g Ca(OH){sub 2}/g TS{sub feather}, 100 deg C, 30 min) improved the methane yield to 0.40 Nm{sup 3}/kg VS, corresponding to 80 % of the theoretical yield. However, prior to digestion, the

A Simple Method of Spectrum Processing for β-ray Measurement without Pretreatment

Energy Technology Data Exchange (ETDEWEB)

Bae, Jun Woo; Kim, Hee Reyoung [UNIST, Ulsan (Korea, Republic of)

2016-10-15

Radioactivity analysis of β-emitting radionuclide is important because of its dangerousness of overexposure. γ-ray has been measured by conventional detector such as NaI(Tl) or high purity germanium (HPGe) detector. But β-ray is hard to detect by those detectors because of its short range. Therefore, liquid scintillation counter (LSC) has been used to measure the radioactivity of pure beta emitter but there is huge problem of organic waste production, though LSC has high efficiency for detection of low energy β-ray. To solve this problem, characterization of β-ray measurement in a plastic scintillator was carried out in this study. There have been some studies about plastic scintillator to measure the β-rays without liquid scintillation method. Plastic scintillator has benefits for detection of β-ray because it has relative low effective atomic number. β-ray and γ-ray spectra in cylindrical plastic scintillator was analyzed and a method of separation of β-ray spectrum was suggested. A simple method of β-ray spectrum separation was suggested. The method was verified by chi-square method to estimate the difference between calculated and measured spectrum. This method was successfully applied by using disc source. For future works, practical radioactive source will be used to acquire the pulse height spectrum. The method can be used for measurement of pure β emitter without pretreatment if this method is verified for practical purpose.

Hydrodynamic cavitation as an efficient pretreatment method for lignocellulosic biomass: A parametric study.

Science.gov (United States)

Terán Hilares, Ruly; de Almeida, Gabriela Faria; Ahmed, Muhammad Ajaz; Antunes, Felipe A F; da Silva, Silvio Silvério; Han, Jong-In; Santos, Júlio César Dos

2017-07-01

Hydrodynamic cavitation (HC), which is a highly destructive force, was employed for pretreatment of sugarcane bagasse (SCB). The efficacy of HC was studied using response surface methodology (RSM) with determining parameters varied: inlet pressure of 1-3bar, temperature of 40-70°C, and alkaline concentration of 0.1-0.3M. At the best condition (3bar, 70°C and 0.3M NaOH), 93.05% and 94.45% of hydrolysis yield of cellulose and hemicellulose, respectively, were obtained within 30min of pretreatment time. Also, pretreatment time higher than 10min had little to do regarding to SCB composition changes using different orifice plates (16 and 27 holes, with corresponding cavitation number of 0.017 and 0.048, respectively), with higher hydrolysis yield observed at 20min of process. Therefore, HC-based approach could lead to a high yield of hydrolysis, as long as a treatment condition was right; it could be so at mild conditions and at short running time. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparison between wet oxidation and steam explosion as pretreatment methods for enzymatic hydrolysis of sugarcane bagasse

DEFF Research Database (Denmark)

Medina, Carlos Martín; Marcet, M.; Thomsen, Anne Belinda

2008-01-01

, and to a two-fold increase of cellulose content in the pretreated solids, while steam explosion solubilised only 60% of xylan and 35% of lignin and increased cellulose content in the solid material by one third. Wet oxidation formed more aliphatic acids and phenolics, and less furan aldehydes in the liquid......Alkaline wet oxidation and steam explosion pretreatments of sugarcane bagasse were compared with regard to biomass fractionation, formation of by-products, and enzymatic convertibility of the pretreated material. Wet oxidation led to the solubilisation of 82% of xylan and 50% of lignin...... fraction than steam explosion did. A better enzymatic convertibility of cellulose was achieved for the wet-oxidised material (57.4 %) than for the steam-exploded material (48.9 %). Cellulose convertibility was lower for the whole slurry than for the washed solids in both pretreatments, but more...

Dry-air drying at room temperature - a practical pre-treatment method of tree leaves for quantitative analyses of phenolics?

Science.gov (United States)

Tegelberg, Riitta; Virjamo, Virpi; Julkunen-Tiitto, Riitta

2018-03-09

In ecological experiments, storage of plant material is often needed between harvesting and laboratory analyses when the number of samples is too large for immediate, fresh analyses. Thus, accuracy and comparability of the results call for pre-treatment methods where the chemical composition remains unaltered and large number of samples can be treated efficiently. To study if a fast dry-air drying provides an efficient pre-treatment method for quantitative analyses of phenolics. Dry-air drying of mature leaves was done in a drying room equipped with dehumifier (10% relative humidity, room temperature) and results were compared to freeze-drying or freeze-drying after pre-freezing in liquid nitrogen. The quantities of methanol-soluble phenolics of Betula pendula Roth, Betula pubescens Ehrh., Salix myrsinifolia Salisb., Picea abies L. Karsten and Pinus sylvestris L. were analysed with HPLC and condensed tannins were analysed using the acid-butanol test. In deciduous tree leaves (Betula, Salix), the yield of most of the phenolic compounds was equal or higher in samples dried in dry-air room than the yield from freeze-dried samples. In Picea abies needles, however, dry-air drying caused severe reductions in picein, stilbenes, condensed tannin and (+)-catechin concentrations compared to freeze-drying. In Pinus sylvestris highest yields of neolignans but lowest yields of acetylated flavonoids were obtained from samples freeze-dried after pre-freezing. Results show that dry-air drying provides effective pre-treatment method for quantifying the soluble phenolics for deciduous tree leaves, but when analysing coniferous species, the different responses between structural classes of phenolics should be taken into account. Copyright © 2018 John Wiley & Sons, Ltd.

Fast and efficient nanoshear hybrid alkaline pretreatment of corn stover for biofuel and materials production

International Nuclear Information System (INIS)

Wang, Wei; Ji, Shaowen; Lee, Ilsoon

2013-01-01

We report a fast and efficient nano-scale shear hybrid alkaline (NSHA) pretreatment method of lignocellulosic biomass. In this work, corn stover was pretreated in a modified Taylor–Couette reactor with alkali (sodium hydroxide) at room temperature for two minutes. Up to 82% of high cellulose content in the remaining solids was achieved with the novel NSHA pretreatment process. Compared with untreated corn stover, an approximately 4-fold increase in enzymatic cellulose conversion and a 5-fold increase in hemicellulose conversion were achieved. Compositional analysis proved significant removals of both lignin and hemicellulose after the NSHA pretreatment. SEM images revealed that the synergistic effect of NSHA pretreatment caused the severe disruption of biomass structure and exposure of cellulose microfibril aggregates in NSHA pretreated corn stover. Highlights: ► A fast nanoshear hybrid alkaline (NSHA) pretreatment method is reported. ► A modified Taylor–Couette reactor was applied. ► The retention time of the NSHA method is only 2 min. ► A 100% conversion of glucan was achieved in one day. ► NSHA greatly removed both lignin and xylan

Assessment of different pre-treatment methods for the removal of limonene in citrus waste and their effect on methane potential and methane production rate.

Science.gov (United States)

Ruiz, Begoña; de Benito, Amparo; Rivera, José Daniel; Flotats, Xavier

2016-12-01

The objective of this study was to assess the limonene removal efficiency of three pre-treatment methods when applied to citrus waste and to evaluate their effects on the biochemical methane potential and the methane production rate using batch anaerobic tests. The methods tested were based on removal (biological pretreatment by fungi) or recovery (steam distillation and ethanol extraction) of limonene. All the treatments decreased the concentration of limonene in orange peel, with average efficiencies of 22%, 44% and 100% for the biological treatment, steam distillation and ethanol extraction, respectively. By-products from limonene biodegradation by fungi exhibited an inhibitory effect also, not making interesting the biological pretreatment. The methane potential and production rate of the treated orange peel increased significantly after applying the recovery strategies, which separated and recovered simultaneously other inhibitory components of the citrus essential oil. Apart from the high recovery efficiency of the ethanol extraction process, it presented a favourable energy balance. © The Author(s) 2016.

Mobility of arsenic and its compounds in soil and soil solution: the effect of soil pretreatment and extraction methods.

Science.gov (United States)

Száková, J; Tlustos, P; Goessler, W; Frková, Z; Najmanová, J

2009-12-30

The effect of soil extraction procedures and/or sample pretreatment (drying, freezing of the soil sample) on the extractability of arsenic and its compounds was tested. In the first part, five extraction procedures were compared with following order of extractable arsenic portions: 2M HNO(3)>0.43 M CH(3)COOH>or=0.05 M EDTA>or=Mehlich III (0.2M CH(3)COOH+0.25 M NH(4)NO(3)+0.013 M HNO(3)+0.015 M NH(4)F+0.001 M EDTA) extraction>water). Additionally, two methods of soil solution sampling were compared, centrifugation of saturated soil and the use of suction cups. The results showed that different sample pretreatments including soil solution sampling could lead to different absolute values of mobile arsenic content in soils. However, the interpretation of the data can lead to similar conclusions as apparent from the comparison of the soil solution sampling methods (r=0.79). For determination of arsenic compounds mild extraction procedures (0.05 M (NH(4))(2)SO(4), 0.01 M CaCl(2), and water) and soil solution sampling using suction cups were compared. Regarding the real soil conditions the extraction of fresh samples and/or in situ collection of soil solution are preferred among the sample pretreatments and/or soil extraction procedures. However, chemical stabilization of the solutions should be allowed and included in the analytical procedures for determination of individual arsenic compounds.

Fungal pretreatment of straw for enhanced biogas yield

Energy Technology Data Exchange (ETDEWEB)

Feng, Xinmei; Pilar Castillo, Maria del; Schnuerer, Anna

2013-07-01

Among lignocellulosic materials from the agricultural sector, straw is considered to have the biggest potential as a biofuel and therefore also represents a big potential for biogas production. However, the degradation of lignocellulosic materials is somewhat restricted due to the high content of lignin that binds cellulose and hemicellulose and makes them unavailable for microbial degradation. Consequently, low methane yields are achieved. The biodegradability of the lignocellulosic material can be increased by a pretreatment. Optimally the pre-treatment should give an increase in the formation of sugars while avoiding the degradation or loss of carbohydrates and the formation of inhibitory by-products. The treatment should also be cost-effective. Different methods for pre-treatment of lignocellulosic material have been explored, for example thermal, acid, alkaline and oxidative pretreatments. However, they often have a high energy demand. Biological treatment with fungi represents an alternative method for pretreatment of lignocellulosic materials that could be comparably more environmentally friendly, easier to operate and with low energy input. The fungal groups of interest for lignocellulose degradation are the wood decaying fungi, such as the white-, brown-rot and cellulose degraders. The purpose with this work was to increase the biogas potential of straw by using a pretreatment with fungi. Straw was incubated with fungi at aerobic conditions under certain periods of time. The growth and colonization of the straw by the fungi was expected to increase the availability of the lignocellulosic structure of the straw and thus positively affect the biogas potential. In addition also, the spent lignocellulosic material from the cultivation of edible fungi was investigated. We hypothesized that also growth of edible fungi could give a more accessible material and thus give higher biogas potential compared to the substrate before fungal growth.

Dosimetric pre-treatment verification of IMRT using an EPID; clinical experience

International Nuclear Information System (INIS)

Zijtveld, Mathilda van; Dirkx, Maarten L.P.; Boer, Hans C.J. de; Heijmen, Ben J.M.

2006-01-01

Background and purpose: In our clinic a QA program for IMRT verification, fully based on dosimetric measurements with electronic portal imaging devices (EPID), has been running for over 3 years. The program includes a pre-treatment dosimetric check of all IMRT fields. During a complete treatment simulation at the linac, a portal dose image (PDI) is acquired with the EPID for each patient field and compared with a predicted PDI. In this paper, the results of this pre-treatment procedure are analysed, and intercepted errors are reported. An automated image analysis procedure is proposed to limit the number of fields that need human intervention in PDI comparison. Materials and methods: Most of our analyses are performed using the γ index with 3% local dose difference and 3 mm distance to agreement as reference values. Scalar parameters are derived from the γ values to summarize the agreement between measured and predicted 2D PDIs. Areas with all pixels having γ values larger than one are evaluated, making decisions based on clinically relevant criteria more straightforward. Results: In 270 patients, the pre-treatment checks revealed four clinically relevant errors. Calculation of statistics for a group of 75 patients showed that the patient-averaged mean γ value inside the field was 0.43 ± 0.13 (1 SD) and only 6.1 ± 6.8% of pixels had a γ value larger than one. With the proposed automated image analysis scheme, visual inspection of images can be avoided in 2/3 of the cases. Conclusion: EPIDs may be used for high accuracy and high resolution routine verification of IMRT fields to intercept clinically relevant dosimetric errors prior to the start of treatment. For the majority of fields, PDI comparison can fully rely on an automated procedure, avoiding excessive workload

COMPARISON OF TWO CHEMICAL PRETREATMENTS OF RICE STRAW FOR BIOGAS PRODUCTION BY ANAEROBIC DIGESTION

Directory of Open Access Journals (Sweden)

Zilin Song,

2012-06-01

Full Text Available Lignocellulosic biomass is considered the most abundant renewable resource that has the potential to contribute remarkably in the supply of biofuel. Previous studies have shown that chemical pretreatment prior to anaerobic digestion (AD can increase the digestibility of lignocellulosic biomass and methane yield. In the present study, the effect of rice straw pretreatment using ammonium hydroxide (NH3•H2O and hydrogen peroxide (H2O2 on the biogasification performance through AD was investigated. A self-designed, laboratory-scale, and continuous anaerobic biogas digester was used for the evaluation. Results showed that the contents of the rice straw, i.e. the lignin, cellulose, and hemicellulose were degraded significantly after the NH3•H2O and H2O2 treatments, and that biogas production from all pretreated rice straw increased. In addition, the optimal treatments for biogas production were the 4% and 3% H2O2 treatments (w/w, which yielded 327.5 and 319.7 mL/gVS, biogas, respectively, higher than the untreated sample. Biogas production from H2O2 pretreated rice straw was more favorable than rice straw pretreated with same concentration of ammonia, ranking in the order of 4% ≈ 3% > 2% > 1%. The optimal amount of H2O2 treatment for rice straw biogas digestion is 3% when economics and biogas yields are considered.

Current Pretreatment Technologies for the Development of Cellulosic Ethanol and Biorefineries.

Science.gov (United States)

Silveira, Marcos Henrique Luciano; Morais, Ana Rita C; da Costa Lopes, Andre M; Olekszyszen, Drielly Nayara; Bogel-Łukasik, Rafał; Andreaus, Jürgen; Pereira Ramos, Luiz

2015-10-26

Lignocellulosic materials, such as forest, agriculture, and agroindustrial residues, are among the most important resources for biorefineries to provide fuels, chemicals, and materials in such a way to substitute for, at least in part, the role of petrochemistry in modern society. Most of these sustainable biorefinery products can be produced from plant polysaccharides (glucans, hemicelluloses, starch, and pectic materials) and lignin. In this scenario, cellulosic ethanol has been considered for decades as one of the most promising alternatives to mitigate fossil fuel dependence and carbon dioxide accumulation in the atmosphere. However, a pretreatment method is required to overcome the physical and chemical barriers that exist in the lignin-carbohydrate composite and to render most, if not all, of the plant cell wall components easily available for conversion into valuable products, including the fuel ethanol. Hence, pretreatment is a key step for an economically viable biorefinery. Successful pretreatment method must lead to partial or total separation of the lignocellulosic components, increasing the accessibility of holocellulose to enzymatic hydrolysis with the least inhibitory compounds being released for subsequent steps of enzymatic hydrolysis and fermentation. Each pretreatment technology has a different specificity against both carbohydrates and lignin and may or may not be efficient for different types of biomasses. Furthermore, it is also desirable to develop pretreatment methods with chemicals that are greener and effluent streams that have a lower impact on the environment. This paper provides an overview of the most important pretreatment methods available, including those that are based on the use of green solvents (supercritical fluids and ionic liquids). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Short-term chemical pretreatment cannot replace curettage in photodynamic therapy

DEFF Research Database (Denmark)

Nissen, Christoffer V; Wiegell, Stine Regin; Philipsen, Peter Alshede

2016-01-01

pretreatment with curettage and two combination ointments containing calcipotriol/betamethasone and salicylic acid/betamethasone affect PpIX fluorescence after the application of methyl aminolevulinate MAL and 5-aminolevulinic acid (BF-200 ALA). METHODS: Four fields on the forearms of 30 healthy volunteers...... were pretreated with curettage or short-term application of calcipotriol/betamethasone or salicylic acid/betamethasone for 20 min. Two fields were not pretreated, thus serving as reference. After pretreatment, MAL or BF-200 ALA was applied for 24 h, and PpIX fluorescence was measured hourly from 1 to 5...... h and after 18, 21 and 24 h. RESULTS: Curettage significantly enhanced PpIX fluorescence for MAL from 1 to 21 h (P salicylic acid...

Process intensification effect of ball milling on the hydrothermal pretreatment for corn straw enzymolysis

International Nuclear Information System (INIS)

Yuan, Zhengqiu; Long, Jinxing; Wang, Tiejun; Shu, Riyang; Zhang, Qi; Ma, Longlong

2015-01-01

Highlights: • Novel pretreatment of ball milling combined with hydrothermal method was presented. • Intensification effect of ball milling was significant for corn straw enzymolysis. • Ball milling destroyed the physical structure of corn straw. • Chemical (liquid mixture) method removed lignin and hemicellulose. • Glucose yield increased from 0.41 to 13.86 mg mL −1 under the optimized condition. - Abstract: Enhancement of the cellulose accessibility is significant for biomass enzymatic hydrolysis. Here, we reported an efficient combined pretreatment for corn straw enzymolysis using ball milling and dilute acid hydrothermal method (a mixture solvent of H 2 O/ethanol/sulfuric acid/hydrogen peroxide liquid). The process intensification effect of ball milling on the pretreatment of the corn straw was studied through the comparative characterization of the physical–chemical properties of the raw and pretreated corn straw using FT-IR, BET, XRD, SEM, and HPLC analysis. The effect of the pretreatment temperature was also investigated. Furthermore, various pretreatment methods were compared as well. Moreover, the pretreatment performance was measured by enzymolysis. The results showed that ball milling had a significant process intensification effect on the corn straw enzymolysis. The glucose concentration was dramatically increased from 0.41 to 13.86 mg mL −1 after the combined treatment of ball milling and hydrothermal. The efficient removal of lignin and hemicellulose and the enlargement of the surface area were considered to be responsible for this significant increase based on the intensive analysis on the main components and the physical–chemical properties of the raw and pretreated corn straw

Accommodating Uncertainty in Prior Distributions

Energy Technology Data Exchange (ETDEWEB)

Picard, Richard Roy [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Vander Wiel, Scott Alan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-01-19

A fundamental premise of Bayesian methodology is that a priori information is accurately summarized by a single, precisely de ned prior distribution. In many cases, especially involving informative priors, this premise is false, and the (mis)application of Bayes methods produces posterior quantities whose apparent precisions are highly misleading. We examine the implications of uncertainty in prior distributions, and present graphical methods for dealing with them.

Towards a method of rapid extraction of strontium-90 from urine: urine pretreatment and alkali metal removal

Energy Technology Data Exchange (ETDEWEB)

Hawkins, C. [Argonne National Lab. (ANL), Argonne, IL (United States); Dietz, M. [Argonne National Lab. (ANL), Argonne, IL (United States); Kaminski, M. [Argonne National Lab. (ANL), Argonne, IL (United States); Mertz, C. [Argonne National Lab. (ANL), Argonne, IL (United States); Shkrob, I. [Argonne National Lab. (ANL), Argonne, IL (United States)

2016-03-01

A technical program to support the Centers of Disease Control and Prevention is being developed to provide an analytical method for rapid extraction of Sr-90 from urine, with the intent of assessing the general population’s exposure during an emergency response to a radiological terrorist event. Results are presented on the progress in urine sample preparation and chemical separation steps that provide an accurate and quantitative detection of Sr-90 based upon an automated column separation sequence and a liquid scintillation assay. Batch extractions were used to evaluate the urine pretreatment and the column separation efficiency and loading capacity based upon commercial, extractant-loaded resins. An efficient pretreatment process for decolorizing and removing organics from urine without measurable loss of radiostrontium from the sample was demonstrated. In addition, the Diphonix® resin shows promise for the removal of high concentrations of common strontium interferents in urine as a first separation step for Sr-90 analysis.

A highly sensitive and specific method for the screening detection of genetically modified organisms based on digital PCR without pretreatment.

Science.gov (United States)

Fu, Wei; Zhu, Pengyu; Wang, Chenguang; Huang, Kunlun; Du, Zhixin; Tian, Wenying; Wang, Qin; Wang, Huiyu; Xu, Wentao; Zhu, Shuifang

2015-08-04

Digital PCR has developed rapidly since it was first reported in the 1990 s. It was recently reported that an improved method facilitated the detection of genetically modified organisms (GMOs). However, to use this improved method, the samples must be pretreated, which could introduce inaccuracy into the results. In our study, we explored a pretreatment-free digital PCR detection method for the screening for GMOs. We chose the CaMV35s promoter and the NOS terminator as the templates in our assay. To determine the specificity of our method, 9 events of GMOs were collected, including MON810, MON863, TC1507, MIR604, MIR162, GA21, T25, NK603 and Bt176. Moreover, the sensitivity, intra-laboratory and inter-laboratory reproducibility of our detection method were assessed. The results showed that the limit of detection of our method was 0.1%, which was lower than the labeling threshold level of the EU. The specificity and stability among the 9 events were consistent, respectively. The intra-laboratory and inter-laboratory reproducibility were both good. Finally, the perfect fitness for the detection of eight double-blind samples indicated the good practicability of our method. In conclusion, the method in our study would allow more sensitive, specific and stable screening detection of the GMO content of international trading products.

The Retentive Strength of Cemented Zirconium Oxide Crowns after Dentin Pretreatment with Desensitizing Paste Containing 8% Arginine and Calcium Carbonate

Science.gov (United States)

Pilo, Raphael; Harel, Noga; Nissan, Joseph; Levartovsky, Shifra

2016-01-01

The effect of dentin pretreatment with Desensitizing Paste containing 8% arginine and calcium carbonate on the retention of zirconium oxide (Y-TZP) crowns was tested. Forty molar teeth were mounted and prepared using a standardized protocol. Y-TZP crowns were produced using computer-aided design and computer-aided manufacturing (CAD-CAM) technology. The 40 prepared teeth were either pretreated with Desensitizing Paste or not pretreated. After two weeks, each group was subdivided into two groups, cemented with either Resin Modified Glass Ionomer Cement (RMGIC) or Self Adhesive Resin Cement (SARC)). Prior to cementation, the surface areas of the prepared teeth were measured. After aging, the cemented crown-tooth assemblies were tested for retentive strength using a universal testing machine. The debonded surfaces of the teeth and crowns were examined microscopically at 10× magnification. Pretreating the dentin surfaces with Desensitizing Paste prior to cementation did not affect the retention of the Y-TZP crowns. The retentive values for RMGIC (3.04 ± 0.77 MPa) were significantly higher than those for SARC (2.28 ± 0.58 MPa). The predominant failure modes for the RMGIC and SARC were adhesive cement-dentin and adhesive cement-crown, respectively. An 8.0% arginine and calcium carbonate in-office desensitizing paste can be safely used to reduce post-cementation sensitivity without reducing the retentive strength of Y-TZP crowns. PMID:27023532

The Retentive Strength of Cemented Zirconium Oxide Crowns after Dentin Pretreatment with Desensitizing Paste Containing 8% Arginine and Calcium Carbonate

Directory of Open Access Journals (Sweden)

Raphael Pilo

2016-03-01

Full Text Available The effect of dentin pretreatment with Desensitizing Paste containing 8% arginine and calcium carbonate on the retention of zirconium oxide (Y-TZP crowns was tested. Forty molar teeth were mounted and prepared using a standardized protocol. Y-TZP crowns were produced using computer-aided design and computer-aided manufacturing (CAD-CAM technology. The 40 prepared teeth were either pretreated with Desensitizing Paste or not pretreated. After two weeks, each group was subdivided into two groups, cemented with either Resin Modified Glass Ionomer Cement (RMGIC or Self Adhesive Resin Cement (SARC. Prior to cementation, the surface areas of the prepared teeth were measured. After aging, the cemented crown-tooth assemblies were tested for retentive strength using a universal testing machine. The debonded surfaces of the teeth and crowns were examined microscopically at 10× magnification. Pretreating the dentin surfaces with Desensitizing Paste prior to cementation did not affect the retention of the Y-TZP crowns. The retentive values for RMGIC (3.04 ± 0.77 MPa were significantly higher than those for SARC (2.28 ± 0.58 MPa. The predominant failure modes for the RMGIC and SARC were adhesive cement-dentin and adhesive cement-crown, respectively. An 8.0% arginine and calcium carbonate in-office desensitizing paste can be safely used to reduce post-cementation sensitivity without reducing the retentive strength of Y-TZP crowns.

Long-term carbimazole pretreatment reduces the efficacy of radioiodine therapy

Directory of Open Access Journals (Sweden)

C Shivaprasad

2015-01-01

Full Text Available Introduction: Data from several studies suggest that pretreatment with antithyroid drugs (ATD before 131 I increases the risk of treatment failure. This effect has been demonstrated more consistently with propylthiouracil than with carbimazole (CMZ or methimazole (MMI. Men with Graves′ disease (GD have a lower rate of remission with 131 I compared to women and the impact of long-term ATD pretreatment on the success of 131 I is unknown. The objective of our study was to compare the efficacy of fixed doses of radioiodine between patients with and without long-term CMZ pretreatment. Materials and Methods: We performed a retrospective study on 335 male patients with GD treated with 131 I from 1998 to 2008. 148 patients had been pretreated with CMZ, and the remaining 187 patients received 131 I without pretreatment. We compared the success rate of a single dose of 131 I, between patients with and without long-term CMZ pretreatment. Results: The success rate of a single dose of 131 I was significantly higher in patients without pretreatment than in patients who were pretreated with CMZ (91.4% vs. 82.3%, P = 0.01. The rate of hypothyroidism in the first 6 months after 131 I therapy was significantly higher in patients without pretreatment (55.1% vs. 44.6%, P = 0.05. There was also a trend for higher cumulative rate of hypothyroidism at last follow-up in nonpretreated patients (78.1% vs. 69.7%. Conclusion: Male patients with Graves′ hyperthyroidism pretreated with CMZ have lower efficacy with 131I therapy compared to nonpretreated patients. CMZ pretreatment given for a prolonged period reduces the efficacy of 131 I therapy.

Assessment of Methods to Pretreat Microalgal Biomass for Enhanced Biogas Production

Directory of Open Access Journals (Sweden)

Aline de L. Marques

2018-06-01

Full Text Available In anaerobic digestion of microalgae, the intracellular material may remain intact due to the non-ruptured membrane and/or cell wall, reducing the methane yield. Therefore, different pretreatment methods were evaluated for the solubilization of microalgae Scenedesmus sp. The anaerobic digestion of biomass hydrolyzed at 150 °C for 60 min with sulfuric acid 0.1% v/v showed higher methane yield (204-316 mL methane/g volatile solids applied compared to raw biomass (104-163 mL methane/g volatile solids applied. The replacement of sulfuric acid with carbonic acid (by bubbling carbon dioxide up to pH 2.0 provided results similar to those obtained with sulfuric acid, reaching solubilization of 41.6% of the biomass. This result shows that part of the flue gas (containing carbon dioxide and other acid gases as well as high temperatures may be used for the hydrolysis of the residual biomass from microalgae, thus lowering operational costs (e.g., energy consumption and chemical input.

Lignocellulosic Biomass Pretreatment Using AFEX

Science.gov (United States)

Balan, Venkatesh; Bals, Bryan; Chundawat, Shishir P. S.; Marshall, Derek; Dale, Bruce E.

Although cellulose is the most abundant organic molecule, its susceptibility to hydrolysis is restricted due to the rigid lignin and hemicellulose protection surrounding the cellulose micro fibrils. Therefore, an effective pretreatment is necessary to liberate the cellulose from the lignin-hemicellulose seal and also reduce cellulosic crystallinity. Some of the available pretreatment techniques include acid hydrolysis, steam explosion, ammonia fiber expansion (AFEX), alkaline wet oxidation, and hot water pretreatment. Besides reducing lignocellulosic recalcitrance, an ideal pretreatment must also minimize formation of degradation products that inhibit subsequent hydrolysis and fermentation. AFEX is an important pretreatment technology that utilizes both physical (high temperature and pressure) and chemical (ammonia) processes to achieve effective pretreatment. Besides increasing the surface accessibility for hydrolysis, AFEX promotes cellulose decrystallization and partial hemicellulose depolymerization and reduces the lignin recalcitrance in the treated biomass. Theoretical glucose yield upon optimal enzymatic hydrolysis on AFEX-treated corn stover is approximately 98%. Furthermore, AFEX offers several unique advantages over other pretreatments, which include near complete recovery of the pretreatment chemical (ammonia), nutrient addition for microbial growth through the remaining ammonia on pretreated biomass, and not requiring a washing step during the process which facilitates high solid loading hydrolysis. This chapter provides a detailed practical procedure to perform AFEX, design the reactor, determine the mass balances, and conduct the process safely.

Potential of potassium hydroxide pretreatment of switchgrass for fermentable sugar production.

Science.gov (United States)

Sharma, Rajat; Palled, Vijaykumar; Sharma-Shivappa, Ratna R; Osborne, Jason

2013-02-01

Chemical pretreatment of lignocellulosic biomass has been extensively investigated for sugar generation and subsequent fuel production. Alkaline pretreatment has emerged as one of the popular chemical pretreatment methods, but most attempts thus far have utilized NaOH for the pretreatment process. This study aimed at investigating the potential of potassium hydroxide (KOH) as a viable alternative alkaline reagent for lignocellulosic pretreatment based on its different reactivity patterns compared to NaOH. Performer switchgrass was pretreated at KOH concentrations of 0.5-2% for varying treatment times of 6-48 h, 6-24 h, and 0.25-1 h at 21, 50, and 121 °C, respectively. The pretreatments resulted in the highest percent sugar retention of 99.26% at 0.5%, 21 °C, 12 h while delignification up to 55.4% was observed with 2% KOH, 121 °C, 1 h. Six pretreatment conditions were selected for subsequent enzymatic hydrolysis with Cellic CTec2® for sugar generation. The pretreatment condition of 0.5% KOH, 24 h, 21 °C was determined to be the most effective as it utilized the least amount of KOH while generating 582.4 mg sugar/g raw biomass for a corresponding percent carbohydrate conversion of 91.8%.

Bioethanol from lignocellulose - pretreatment, enzyme immobilization and hydrolysis kinetics

DEFF Research Database (Denmark)

Tsai, Chien Tai

, the cost of enzyme is still the bottle neck, re-using the enzyme is apossible way to reduce the input of enzyme in the process. In the point view of engineering, the prediction of enzymatic hydrolysis kinetics under different substrate loading, enzyme combination is usful for process design. Therefore...... lignocellulose is the required high cellulase enzyme dosages that increase the processing costs. One method to decrease the enzyme dosage is to re-use BG, which hydrolyze the soluble substrate cellobiose. Based on the hypothesis that immobilized BG can be re-used, how many times the enzyme could be recycled...... liquid and pretreatment time can be reduced, the influence of substrate concentration, pretreatment time and temperature were investigated and optimized. Pretreatment of barley straw by [EMIM]Ac, correlative models were constructed using 3 different pretreatment parameters (temperature, time...

Optimization of SHINE Process: Design and Verification of Plant-Scale AG 1 Anion-Exchange Concentration Column and Titania Sorbent Pretreatment

Energy Technology Data Exchange (ETDEWEB)

Stepinski, Dominique C. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Abdul, Momen [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Youker, Amanda J. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Rotsch, David A. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Tkac, Peter [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Chemerisov, Sergey [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Vandegrift, George F. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division

2016-06-01

Argonne National Laboratory has developed a Mo-recovery and -purification system for the SHINE medical technologies process, which uses a uranyl sulfate solution for the accelerator-driven production of Mo-99. The objective of this effort is to reduce the processing time for the acidification of the Mo-99 product prior to loading onto a concentration column and concentration of the Mo-99 product solution. Two methods were investigated: (1) the replacement of the titania concentration column by an anion-exchange column to decrease processing time and increase the radioiodine-decontamination efficiency and (2) pretreatment of the titania sorbent to improve its effectiveness for the Mo-recovery and -concentration columns. Promising results are reported for both methods.

Electrochemical impedance spectroscopic investigation of the role of alkaline pre-treatment in corrosion resistance of a silane coating on magnesium alloy, ZE41

Energy Technology Data Exchange (ETDEWEB)

Chakraborty Banerjee, P. [Department of Chemical Engineering, Monash University, Clayton, VIC-3800 (Australia); CAST Cooperative Research Centre, Hawthorn, VIC-3122 (Australia); Singh Raman, R.K., E-mail: raman.singh@eng.monash.edu.a [Department of Chemical Engineering, Monash University, Clayton, VIC-3800 (Australia); Department of Mechanical and Aerospace Engineering, Monash University, Clayton, VIC-3800 (Australia)

2011-04-15

The protective performance of the coatings of bis-1,2-(triethoxysilyl) ethane (BTSE) on ZE41 magnesium alloy with different surface pre-treatments were evaluated using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) in 0.1 M sodium chloride solution. Electrical equivalent circuits were developed based upon hypothetical corrosion mechanisms and simulated to correspond to the experimental data. The morphology and cross section of the alloy subjected to different pre-treatments and coatings were characterized using scanning electron microscope. A specific alkaline pre-treatment of the substrate prior to the coating has been found to improve the corrosion resistance of the alloy.

Electrochemical impedance spectroscopic investigation of the role of alkaline pre-treatment in corrosion resistance of a silane coating on magnesium alloy, ZE41

International Nuclear Information System (INIS)

Chakraborty Banerjee, P.; Singh Raman, R.K.

2011-01-01

The protective performance of the coatings of bis-1,2-(triethoxysilyl) ethane (BTSE) on ZE41 magnesium alloy with different surface pre-treatments were evaluated using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) in 0.1 M sodium chloride solution. Electrical equivalent circuits were developed based upon hypothetical corrosion mechanisms and simulated to correspond to the experimental data. The morphology and cross section of the alloy subjected to different pre-treatments and coatings were characterized using scanning electron microscope. A specific alkaline pre-treatment of the substrate prior to the coating has been found to improve the corrosion resistance of the alloy.

Release of non-methane organic compounds during simulated landfilling of aerobically pretreated municipal solid waste.

Science.gov (United States)

Zhang, Yuanyuan; Yue, Dongbei; Liu, Jianguo; Lu, Peng; Wang, Ying; Liu, Jing; Nie, Yongfeng

2012-06-30

Characteristics of non-methane organic compounds (NMOCs) emissions during the anaerobic decomposition of untreated (APD-0) and four aerobically pretreated (APD-20, APD-39, APD-49, and APD-63) samples of municipal solid waste (MSW) were investigated in laboratory. The cumulative mass of the NMOCs of APD-20, APD-39, APD-49, and APD-63 accounted for 15%, 9%, 16%, and 15% of that of APD-0, respectively. The intensities of the NMOC emissions calculated by dividing the cumulative NMOC emissions by the quantities of organic matter removed (Q(VS)) decreased from 4.1 mg/kg Q(VS) for APD-0 to 0.8-3.4 mg/kg Q(VS) for aerobically pretreated MSW. The lipid and starch contents might have significant impact on the intensity of the NMOC emissions. Alkanes dominated the NMOCs released from the aerobically pretreated MSW, while oxygenated compounds were the chief component of the NMOCs generated from untreated MSW. Aerobic pretreatment of MSW prior to landfilling reduces the organic content of the waste and the intensity of the NMOC emissions, and increases the odor threshold, thereby reducing the environmental impact of landfills. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effects of different chlorhexidine pretreatments on adhesion of metal brackets in vitro

Directory of Open Access Journals (Sweden)

Frey Corinne

2012-12-01

Full Text Available Abstract Objective To investigate the effect of chlorhexidine applications in various forms and concentrations on adhesion and failure modes of metal brackets in vitro. Material and methods Ninety bovine enamel specimens were allocated to six groups (n=15. Metal brackets were bonded on all specimens after chlorhexidine pre-treatments forming the following groups: (1 untreated specimens (control; (2 40% varnish (EC40, Biodent BV, Netherlands, remnants removed with brushing mimicking patient cleaning; (3 40% varnish (EC40, remnants removed with brushing mimicking professional cleaning; (4 1% varnish (Cervitec Plus, Ivoclar vivadent, Schaan, Liechtenstein, remnants not removed; (5 brushed with% 1 gel (Corsodyl, GlaxoSmithKline, Münchenbuchsee, Germany, remnants not removed; (6 immersed in 0.07% mouthrinse (Corsodyl, GlaxoSmithKline, Münchenbuchsee, Germany, remnant not rinsed. Debonding of brackets was performed using a universal testing machine. Data were analysed using one-way ANOVA and post-hoc Scheffé test. Results Group 4 performed significantly inferior than all the other groups and the control. Group 4 presented the highest number of adhesive failures at the enamel-resin interface whereas in other groups no failures at adhesive-resin interface was observed. Conclusion Presence of chlorhexidine varnish prior to bracket bonding adversely affects adhesion. Concentration of chlorhexidine pre-treatment has no influence on shear bond strength.

Effect of pretreatments and processing conditions on anti-nutritional factors in climbing bean flours

Directory of Open Access Journals (Sweden)

Emmanuel Mugabo

2017-04-01

Full Text Available It is difficult for many Rwandans to utilize climbing bean seeds (Phaseolus vulgaris. L mainly because of longer cooking time (2 hours and the high consumption of basic fuel. Climbing beans also contain anti-nutritional factors such tannins, phytates, trypsin inhibitors and phytohemagglutinins that limit nutrient absorption. One way to solve this problem is to utilize the flour of climbing beans made from different treatments and processing methods. In this study, climbing beans were pre-treated by soaking them in water for 24 hours, soaking in 2% sodium bicarbonate solution and steam blanching for 10 minutes. After that, pre-treated climbing beans were processed into flours by processing methods such as roasting, cooking and germination where anti-nutritional factors were reduced. The pretreatments did not significantly (p>0.05 affect phytates in climbing bean flours but processing conditions significantly (p<0.05 reduced it. Pretreatments and processing conditions significantly (p<0.05 reduced tannin content. The pretreatments followed by different processing conditions significantly (p<0.05 decreased trypsin inhibitors content. The great significant decrease in phytohemagglutinins content was observed in pretreatment followed by different processing methods. All pretreatments and processing conditions effectively decreased anti-nutritional factors at low level. However, pretreatments or untreated followed by germination and roasting were found to be the most and the least effective respectively.  Making flour from germinated climbing bean seeds is a good option for sustainable food processing as it reduces anti-nutritional factors. It is an inexpensive method in terms of time, energy and fuel for Rwandan households, restaurants and industries where climbing bean seeds are integral part of daily meal.

UHPLC-LTQ-Orbitrap MS combined with spike-in method for plasma metabonomics analysis of acute myocardial ischemia rats and pretreatment effect of Danqi Tongmai tablet.

Science.gov (United States)

Yan, Bingpeng; Deng, Yanping; Hou, Jinjun; Bi, Qirui; Yang, Min; Jiang, Baohong; Liu, Xuan; Wu, Wanying; Guo, Dean

2015-02-01

Undoubtedly, metabonomics can reveal the comprehensive efficacies of traditional Chinese medicine (TCM) formulae and its complex mechanism at the molecular biological level. In this study, an attempt was made to address the pretreatment effect of a TCM formula. In this case, as a critical point, we should first know how to really reflect the various endogenous metabolites in a disease status before a TCM formula is employed in a therapeutic procedure. Here, we explored an approach that combined high resolution LTQ-Orbitrap mass spectrometry with a spike-in method to characterize endogenous metabolites in acute myocardial ischemia (AMI) rats. As a result, 19 potential biomarkers in rat plasma were identified and 10 related disturbed pathways were perturbed in the early stages of AMI development. Subsequently, the metabonomics method was applied to investigate the pretreatment effect of the TCM formula named the Danqi Tongmai tablet (DQTM). The results revealed that the DQTM pretreatment could reduce the AMI injury and partially regulate the perturbed TCA cycle and amino and nucleotide metabolism, which were presumable related to energy metabolism and myocardial cells apoptosis/necrosis. In conclusion, UHPLC-LTQ-Orbitrap MS combined with a spike-in method were successfully applied to the metabonomics analysis of DQTM, which demonstrated that not only a comprehensive metabolic profile in the early stages of AMI development was achieved, but also that the underlying holistic efficacies were assessed and it was helpful to understand the possible mechanism of pretreatment with DQTM.

Antibacterial effect of surface pretreatment techniques against ...

African Journals Online (AJOL)

Objective: The aim of this study was to evaluate the antibacterial surface pretreatment methods against Streptococcus mutans within the infected dentin surface using a tooth cavity model. Material and Methods: Seventy-two cavities were prepared on caries-free third molars (n = 8). After sterilization, teeth were inoculated ...

Pretreatment of enteral nutrition with sodium polystyrene sulfonate: effective, but beware the high prevalence of electrolyte derangements in clinical practice.

Science.gov (United States)

Le Palma, Krisha; Pavlick, Elisha Rampolla; Copelovitch, Lawrence

2018-04-01

Current treatment options for chronic hyperkalemia in children with chronic kidney disease include dietary restrictions or enteral sodium polystyrene sulfonate (SPS); however, dietary restrictions may compromise adequate nutrition and enteral SPS may be limited by palatability, adverse effects and feeding tube obstruction. A potentially safer alternative is to pretreat enteral nutrition (EN) with SPS prior to consumption. The purpose of this study was to evaluate the efficacy and safety of pretreating EN with SPS in pediatric patients with hyperkalemia. We performed a retrospective cohort study between September 2012 and May 2016 at the Children's Hospital of Philadelphia. In all, 14 patients (age range 0.5-53.2 months) who received 19 courses of SPS pretreatment of EN were evaluated. Serum electrolytes were evaluated at baseline and within 1 week of initiating therapy. The primary endpoint was mean change in potassium at 7 days. Secondary endpoints included the mean change in serum sodium, chloride, bicarbonate, calcium, phosphorous and magnesium, as well as the percentage of patients who developed electrolyte abnormalities within the first week of treatment. Serum potassium levels decreased from 6.0 to 4.4 mmol/L (P < 0.001) and serum sodium levels increased from 135.8 to 141.3 mmol/L (P = 0.008) 1 week after initiating SPS pretreatment. No significant differences in mean serum calcium or magnesium levels were noted. Nevertheless, more than half of the courses resulted in at least one electrolyte abnormality, with hypokalemia (31.6%), hypernatremia (26.3%) and hypocalcemia (21.1%) occurring most frequently. Pretreatment of EN with SPS is an effective method for treating chronic hyperkalemia in pediatric patients; however, close monitoring of electrolytes is warranted.

The effect of levocabastine and furosemide pretreatment on hyperreactive response after nasal provocation with hypotonic aerosol in subjects with allergic rhinitis.

Science.gov (United States)

Anzic, Srdjan Ante; Dzepina, Davor; Kalogjera, Livije

2007-11-01

Patients with allergic rhinitis demonstrate hyperreactive response in distilled water nasal provocation, shown by significant increase in nasal airway resistance (NAR). Antihistamines, including topical antihistamine, levocabastine, reduce response in non-specific nasal provocation tests. Furosemide is a diuretic which reduces hyperreactivity in lower airways, but the mode of its action is not yet fully understood. In this study, we hypothesized that either levocabastine or furosemide pre-treatment in allergic rhinitis patients reduced response to nasal challenge with non-isotonic aerosol. To test the hypothesis, we measured the effect of pre-treatment with levocabastine and furosemide in topical application on suppression of hyperreactive response to distilled water nasal inhalation. Nasal resistance was measured, prior to and after the provocation, by active anterior rhinomanometry in two randomized groups of patients, according to pre-treatment, either by levocabastine or furosemide, 20 patients in each group, respectively. Nasal airflow resistance and level of hyperreactive response considering nasal eosinophilia were tested. Significant increase in nasal resistance following provocation was found at baseline conditions (without pre-medication); pre-treatment with levocabastine and furosemide has suppressed such response. Patients with positive nasal eosinophilia showed a significantly higher increase in nasal resistance compared to those with negative smears. Furosemide has shown significantly better protective effect on nasal resistance increase in patients with positive eosinophils nasal smears. Levocabastine and furosemide pre-treatment suppress hyperreactive response to distilled water nasal provocation. Comparison of resistances (pre-treatment vs. without) showed more protective effect of furosemide, measured on both better and worse patent side of nose, in contrast to levocabastine group for which it was shown only on better patent side prior to

Effects of pretreatment methods for hazelnut shell hydrolysate fermentation with Pichia Stipitis to ethanol.

Science.gov (United States)

Arslan, Yeşim; Eken-Saraçoğlu, Nurdan

2010-11-01

In this study, we investigated the use of hazelnut shell as a renewable and low cost lignocellulosic material for bioethanol production for the first time. High lignin content of hazelnut shell is an important obstacle for such a biotransformation. Biomass hydrolysis with acids yields reducing sugar with several inhibitors which limit the fermentability of sugars. The various conditioning methods for biomass and hydrolysate were performed to overcome the toxicity and their effects on the subsequent fermentation of hazelnut shell hydrolysate by Pichia stipitis were evaluated with shaking flasks experiments. Hazelnut shells hydrolysis with 0.7M H(2)SO(4) yielded 49 gl(-1) total reducing sugars and fermentation inhibitors in untreated hydrolysate. First, it was shown that several hydrolysate detoxification methods were solely inefficient in achieving cell growth and ethanol production in the fermentation of hazelnut shell hydrolysates derived from non-delignified biomass. Next, different pretreatments of hazelnut shells were considered for delignification and employed before hydrolysis in conjunction with hydrolysate detoxification to improve alcohol fermentation. Among six delignification methods, the most effective pretreatment regarding to ethanol concentration includes the treatment of shells with 3% (w/v) NaOH at room temperature, which was integrated with sequential hydrolysate detoxification by overliming and then treatment with charcoal twice at 60 degrees C. This treatment brought about a total reduction of 97% in furans and 88.4% in phenolics. Almost all trialed treatments caused significant sugar loss. Under the best assayed conditions, ethanol concentration of 16.79gl(-1) was reached from a hazelnut shell hyrolysate containing initial 50g total reducing sugar l(-1) after partial synthetic xylose supplementation. This value is equal to 91.25% of ethanol concentration that was obtained from synthetic d-xylose under same conditions. The present study

Cellulolytic Enzymes Production via Solid-State Fermentation: Effect of Pretreatment Methods on Physicochemical Characteristics of Substrate.

Science.gov (United States)

Brijwani, Khushal; Vadlani, Praveen V

2011-01-01

We investigated the effect of pretreatment on the physicochemical characteristics-crystallinity, bed porosity, and volumetric specific surface of soybean hulls and production of cellulolytic enzymes in solid-state fermentation of Trichoderma reesei and Aspergillus oryzae cultures. Mild acid and alkali and steam pretreatments significantly increased crystallinity and bed porosity without significant change inholocellulosic composition of substrate. Crystalline and porous steam-pretreated soybean hulls inoculated with T. reesei culture had 4 filter paper units (FPU)/g-ds, 0.6 IU/g-ds β-glucosidase, and 45 IU/g-ds endocellulase, whereas untreated hulls had 0.75 FPU/g-ds, 0.06 IU/g-ds β-glucosidase, and 7.29 IU/g-ds endocellulase enzyme activities. In A. oryzae steam-pretreated soybean hulls had 47.10 IU/g-ds endocellulase compared to 30.82 IU/g-ds in untreated soybean hulls. Generalized linear statistical model fitted to enzyme activity data showed that effects of physicochemical characteristics on enzymes production were both culture and enzyme specific. The paper shows a correlation between substrate physicochemical properties and enzyme production.

Evaluation of pretreatment methods on harvesting hydrogen producing seeds from anaerobic digested organic fraction of municipal solid waste (OFMSW)

Energy Technology Data Exchange (ETDEWEB)

Dong, Li [Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640 (China); Key Laboratory of Renewable Energy and Gas Hydrate, Chinese Academy of Sciences, Guangzhou 510640 (China); Zhenhong, Yuan; Yongming, Sun; Longlong, Ma [Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640 (China)

2010-08-15

In order to harvest high-efficient hydrogen producing seeds, five pretreatment methods (including acid, heat, sonication, aeration and freeze/thawing) were performed on anaerobic digested sludge (AS) which was collected from a batch anaerobic reactor for treating organic fraction of municipal solid waste. The hydrogen production tests were conducted in serum bottles containing 20 gVS/L (24.8 g COD/L) mixture of rice and lettuce powder at 37 C. The experimental results showed that the heat and acid pretreatment completely repressed the methanogenic activity of AS, but acid pretreatment also partially repressed hydrogen production. Sonication, freeze/thawing and aeration did not completely suppress the methanogen activity. The highest hydrogen yields were 119.7, 42.2, 26.0, 23.0, 22.7 and 22.1 mL/gVS for heated, acidified, freeze/thawed, aerated, sonicated and control AS respectively. A pH of about 4.9 was detected at the end of hydrogen producing fermentation for all tests. The selection of an initial pH can markedly affect the hydrogen producing ability for heated and acidified AS. The higher initial pH generated higher hydrogen yield and the highest hydrogen yield was obtained with initial pH 8.9 for heated AS. (author)

Improving production of volatile fatty acids from food waste fermentation by hydrothermal pretreatment.

Science.gov (United States)

Yin, Jun; Wang, Kun; Yang, Yuqiang; Shen, Dongsheng; Wang, Meizhen; Mo, Han

2014-11-01

Food waste (FW) was pretreated by a hydrothermal method and then fermented for volatile fatty acid (VFAs) production. The soluble substance in FW increased after hydrothermal pretreatment (⩽200 °C). Higher hydrothermal temperature would lead to mineralization of the organic compounds. The optimal temperature for organic dissolution was 180 °C, at which FW dissolved 42.5% more soluble chemical oxygen demand than the control. VFA production from pretreated FW fermentation was significantly enhanced compared with the control. The optimal hydrothermal temperature was 160 °C with a VFA yield of 0.908 g/g VSremoval. Butyrate and acetate were the prevalent VFAs followed by propionate and valerate. FW fermentation was inhibited after 200 °C pretreatment. The VFAs were extracted from the fermentation broth by liquid-liquid extraction. The VFA recovery was 50-70%. Thus, 0.294-0.411 g VFAs could be obtained per gram of hydrothermally pretreated FW (in dry weight) by this method. Copyright © 2014 Elsevier Ltd. All rights reserved.

Enzymatic hydrolsis of pretreated rice straw

Energy Technology Data Exchange (ETDEWEB)

Vlasenko, E.Y.; Shoemaker, S.P. [California Inst. of Food and Agricultural Research, Davis, CA (United States); Ding, H. [California Univ., Davis (Canada). Dept. of Food Science and Technology; Labavitch, J.M. [California Univ., Davis, CA (United States). Dept. of Pomology

1997-02-01

California rice straw is being evaluated as a feedstock for production of power and fuel. This paper examines the initial steps in the process: pretreatment of rice straw and enzymatic hydrolysis of the polysaccharides in the pretreated material to soluble sugars. Rice straw was subjected to three distinct pretreatment procedures: acid-catalyzed steam explosion (Swan Biomass Company), acid hydrolysis (U.S. DOE National Renewable Energy Laboratory), and ammonia fiber explosion or AFEX (Texas A and M University). Standard conditions for each pretreatment were used, but none was optimized for rice straw specifically. Six commercial cellulases, products of Genencor International (USA), Novo (Denmark), Iogen (Canada) and Fermtech (Russia) were used for hydrolysis. The Swan- and the acid-pretreatments effectively removed hemicellulose from rice straw, providing high yields of fermentable sugars. The AFEX-pretreatment was distinctly different from other pretreatments in that it did not significantly solubilize hemicellulose. All three pretreatment procedures substantially increased enzymatic digestibility of rice straw. Three commercial Trichoderma-reesei-derived enzyme preparations: Cellulase 100L (Iogen), Spezyme CP (Genencor), and Al (Fermtech), were more active on pretreated rice straw compared than others tested. Conditions for hydrolysis of rice straw using Cellulase 100L were evaluated. The supplementation of this enzyme preparation with cellobiase (Novozyme 188) significantly improved the parameters of hydrolysis for the Swan- and the acid-pretreated materials, but did not affect the hydrolysis of the AFEX-pretreated rice straw. (Author)

Combination of alkaline and microwave pretreatment for disintegration of meat processing wastewater sludge.

Science.gov (United States)

Erden, G

2013-01-01

Meat processing wastewater sludge has high organic content but it is very slow to degrade in biological processes. Anaerobic digestion may be a good alternative for this type of sludge when the hydrolysis, known to be the rate-limiting step of biological sludge anaerobic degradation, could be eliminated by disintegration. This investigation deals with disintegration of meat processing wastewater sludge. Microwave (MW) irradiation and combined alkaline pretreatment and MW irradiation were applied to sludge for disintegration purposes. Disintegration performance of the methods was evaluated with disintegration degree based on total and dissolved organic carbon calculations (DD(TOC)), and the solubilization of volatile solids (S(VS)) in the pretreated sludge. Optimum conditions were found to be 140 degrees C and 30 min for MW irradiation using response surface methodology (RSM) and pH = 13 for combined pretreatment. While DD(TOC) was observed as 24.6% and 54.9, S(VS) was determined as 8.54% and 42.5% for MW pretreated and combined pretreated sludge, respectively. The results clearly show that pre-conditioning of sludge with alkaline pretreatment played an important role in enhancing the disintegration efficiency of subsequent MW irradiation. Disintegration methods also affected the anaerobic biodegradability and dewaterability of sludge. An increase of 23.6% in biogas production in MW irradiated sludge was obtained, comparing to the raw sludge at the end of the 35 days of incubation. This increase was observed as 44.5% combined pretreatment application. While MW pretreatment led to a little improvement of the dewatering performance of sludge, in combined pretreatment NaOH deteriorates the sludge dewaterability.

Effects of low-temperature pretreatment on carbonization of cellulose for the production of biocarbons

Science.gov (United States)

Kwon, Gu-Joong; Kim, Dae-Young; Kang, Kyu-Young

2012-05-01

Pretreatment of cellulose at temperatures below 300 °C prior to carbonization at 1200 °C was studied for the production of high-yield biocarbons. Filter paper as the cellulosic raw material was pyrolyzed by using heating schemes, including 16-h isothermal step at 215-270 °C under nitrogen atmosphere, followed by fast heating up to 600 °C and finally to 1200 °C. Cellulose degradation was completed in the 16-h holding isothermal step at a temperature above 250 °C, as confirmed by IR spectroscopy and X-ray diffraction. The yield of char was increased from 11% to 21% by pretreatment of cellulose after post-treatment at 600 °C or 1200 °C. The BET surface area as the microporosity value was also significantly enhanced from 461 m2/g to 837 m2/g by straight heating of 10 °C/min. These results are thought to be caused by slow heating and stabilizing effects due to pretreatment of cellulose at the critical temperature for degradation.

Conversion of alkaline pretreated empty palm fruit bunch (EPFB) to phenols

International Nuclear Information System (INIS)

Nor Aishah Saidina Amin; Roslindawati Haron

2010-01-01

Various efforts on green chemistry are being directed at producing renewable chemicals. Chemicals derived from biomass can be the basis for building blocks in the chemicals industry. Phenols, traditionally produced from petroleum, can be derived from biomass for naturally-sourced solvents. Lignocellulose biomass consists of cellulose, hemicelluloses and lignin. Lignocellulose components can be altered by various chemical pretreatment methods. EFB contains about 60% cellulose and almost equal portions of lignin and hemicelluloses. Pretreatment of EFB fragmentized and degraded the lignocellulose structure in order to produce chemicals under thermochemical process. In this work, EFB was chemically pretreated with different sodium hydroxide (NaOH) concentrations to concentrated lignocellulose before being pyrolyzed to produce solid, gas and liquid products. Pyrolysis was conducted after the pretreatment step to evaluate the effects of pretreatment process on production and compositions of the bio-oil. The conversions of EFB were reported to be 61wt%, 47wt% and 42 wt%, after pretreatment with 5 wt%, 15 wt% and 25 wt%,NaOH concentrations, respectively. GCMS analysis results revealed the crude bio-oil contained dominantly phenol. Pyrolysis of the alkaline pretreated EFB seemed potential to produce biomass-based phenols. (author)

Pretreatment of americium/curium solutions for vitrification

International Nuclear Information System (INIS)

Rudisill, T.S.

1996-01-01

Vitrification will be used to stabilize an americium/curium (Am/Cm) solution presently stored in F-Canyon for eventual transport to the heavy isotope programs at Oak Ridge National Laboratory. Prior to vitrification, an in-tank oxalate precipitation and a series of oxalic/nitric acid washes will be used to separate these elements and lanthanide fission products from the bulk of the uranium and metal impurities present in the solution. Pretreatment development experiments were performed to understand the behavior of the lanthanides and the metal impurities during the oxalate precipitation and properties of the precipitate slurry. The results of these experiments will be used to refine the target glass composition allowing optimization of the primary processing parameters and design of the solution transfer equipment

High Performance Nanocatalysts Supported on Micro/Nano Carbon Structures Using Ethanol Immersion Pretreatment for Micro DMFCs

International Nuclear Information System (INIS)

Lin, Liang-You; Wu, Yi-Shiuan; Chang, Chaun; Tseng, Fan-Gang

2013-01-01

In this paper, highly dense platinum (Pt) nanocatalysts were successfully deposited on the hydrophilically-treated nano/micro carbon supports with an ethanol (EtOH) immersion pretreatment and an acidic treatment for the performance improvement of methanol oxidation reaction (MOR). In order to thoroughly immerse the three-dimensional, interwoven structures of the carbon cloth fibers with a 6 M sulfuric acid surface modification, which increasing more oxygen-containing functional groups on the surfaces of the carbon supports, the EtOH immersion pretreatment of the carbon supports was utilized prior to the sulfuric acid treatment. Subsequently, Pt catalysts were reduced on the modified carbon supports by a homemade open-loop reduction system (OLRS) [1] For comparisons, carbon cloth (CC) and carbon nanotube on CC (CNT/CC) supports were employed with and without EtOH immersion pretreatments before Pt catalyst reduction. In the cyclic voltammetry (CV) curves, the electrosorption charges of hydrogen ion (Q H ) and the peak current density (I P ) of the fabricated Pt/CC and Pt/CNT/CC electrodes with the EtOH immersion pretreatments can efficiently be enhanced due to more active Pt sites for electrocatalytic reactions

The relationship between pretreatment dietary composition and weight loss during a randomised trial of different diet approaches.

Science.gov (United States)

McVay, M A; Jeffreys, A S; King, H A; Olsen, M K; Voils, C I; Yancy, W S

2015-02-01

Identifying pretreatment dietary habits that are associated with weight-loss intervention outcomes could help guide individuals' selection of weight-loss approach among competing options. A pretreatment factor that may influence weight-loss outcomes is macronutrient intake. Overweight and obese Durham Veterans Affairs outpatients were randomised to a weight-loss intervention with a low-carbohydrate diet (n = 71) or orlistat medication therapy plus a low-fat diet (n = 73). Percentage fat, carbohydrate and protein intake prior to treatment were measured using 4-day food records. Linear mixed-effects models were used to determine whether pretreatment percentage macronutrient intake influenced weight trajectories and weight loss in each weight-loss condition. Participant's mean age was 53 years, baseline body mass index was 39.3 kg m(-2) and 72% were male. A higher pretreatment percentage carbohydrate intake was associated with less rapid initial weight loss (P = 0.02) and less rapid weight regain (P = 0.03) in the low-carbohydrate diet condition but was not associated with weight trajectories in the orlistat plus low-fat diet condition. In both conditions, a higher pretreatment percentage fat intake was associated with more rapid weight regain (P loss on study completion in either condition. Selection of a weight-loss approach on the basis of pretreatment macronutrient intake is unlikely to improve weight outcomes at the end of a 1-year treatment. However, pretreatment macronutrient intake may have implications for tailoring of interventions to slow weight regain after weight loss. © 2013 The British Dietetic Association Ltd.

A method to modify PVDF microfiltration membrane via ATRP with low-temperature plasma pretreatment

Energy Technology Data Exchange (ETDEWEB)

Han, Yu [School of Marine Science, Ningbo University, Fenghua Road 818, Ningbo, 315211 (China); Ningbo University of Technology, Fenghua Road 201, Ningbo, 315211 (China); Song, Shuijun [School of Marine Science, Ningbo University, Fenghua Road 818, Ningbo, 315211 (China); Zhejiang University of Science Technology, Liuhe Road 318, Hangzhou, 310023 (China); Lu, Yin, E-mail: luyin@nbu.edu.cn [School of Marine Science, Ningbo University, Fenghua Road 818, Ningbo, 315211 (China); Zhu, Dongfa [School of Marine Science, Ningbo University, Fenghua Road 818, Ningbo, 315211 (China)

2016-08-30

Highlights: • We report a simple method to modify hydrophobic PVDF modification membrane. • Surface modification of PVDF membrane via ATRP with plasma pre-treatment. • ATRP grafting of SBMA onto the PVDF membrane surface form PVDF-g-SBMA membrane. • PVDF-g-SBMA membrane shows superior antifouling properties and hydrophilic. - Abstract: The hydrophilic modification of a polyvinylidene fluoride (PVDF) microfiltration membrane via pretreatment with argon plasma and direct surface-initiated atom transfer radical polymerization (ATRP) was studied. Both modified and unmodified PVDF membranes were characterized by Fourier transform infrared spectroscopy (FTIR), water contact angle, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and pore size distribution measurements. FTIR and XPS spectra confirmed that sulfobetaine methacrylate (SBMA) had been grafted onto the membrane surface. The initial contact angle decreased from 87.0° to 29.8° and a water drop penetrated into the modified membrane completely in 8 s. The pore size distribution of the modified membrane exhibited a smaller mean value than that of the original membrane. The antifouling properties of the modified PVDF membrane were evaluated by a filtration test using bovine serum albumin (BSA) solution. The results showed that the initial flux of the modified membrane increased from 2140.1 L/m{sup 2} h to 2812.7 L/m{sup 2} h and the equilibrium flux of BSA solution increased from 31 L/m{sup 2} h to 53 L/m{sup 2} h.

A method to modify PVDF microfiltration membrane via ATRP with low-temperature plasma pretreatment

International Nuclear Information System (INIS)

Han, Yu; Song, Shuijun; Lu, Yin; Zhu, Dongfa

2016-01-01

Highlights: • We report a simple method to modify hydrophobic PVDF modification membrane. • Surface modification of PVDF membrane via ATRP with plasma pre-treatment. • ATRP grafting of SBMA onto the PVDF membrane surface form PVDF-g-SBMA membrane. • PVDF-g-SBMA membrane shows superior antifouling properties and hydrophilic. - Abstract: The hydrophilic modification of a polyvinylidene fluoride (PVDF) microfiltration membrane via pretreatment with argon plasma and direct surface-initiated atom transfer radical polymerization (ATRP) was studied. Both modified and unmodified PVDF membranes were characterized by Fourier transform infrared spectroscopy (FTIR), water contact angle, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and pore size distribution measurements. FTIR and XPS spectra confirmed that sulfobetaine methacrylate (SBMA) had been grafted onto the membrane surface. The initial contact angle decreased from 87.0° to 29.8° and a water drop penetrated into the modified membrane completely in 8 s. The pore size distribution of the modified membrane exhibited a smaller mean value than that of the original membrane. The antifouling properties of the modified PVDF membrane were evaluated by a filtration test using bovine serum albumin (BSA) solution. The results showed that the initial flux of the modified membrane increased from 2140.1 L/m"2 h to 2812.7 L/m"2 h and the equilibrium flux of BSA solution increased from 31 L/m"2 h to 53 L/m"2 h.

Combined (alkaline+ultrasonic) pretreatment effect on sewage sludge disintegration.

Science.gov (United States)

Kim, Dong-Hoon; Jeong, Emma; Oh, Sae-Eun; Shin, Hang-Sik

2010-05-01

The individual effects of alkaline (pH 8-13) and ultrasonic (3750-45,000kJ/kg TS) pretreatments on the disintegration of sewage sludge were separately tested, and then the effect of combining these two methods at different intensity levels was investigated using response surface methodology (RSM). In the combined pretreatment, ultrasonic treatment was applied to the alkali-pretreated sludge. While the solubilization (SCOD/TCOD) increase was limited to 50% in individual pretreatments, it reached 70% in combined pretreatment, and the results clearly showed that preconditioning of sludge at high pH levels played a crucial role in enhancing the disintegration efficiency of the subsequent ultrasonic pretreatment. By applying regression analysis, the disintegration degree (DD) was fitted based on the actual value to a second order polynomial equation: Y=-172.44+29.82X(1)+5.30x10(-3)X(2)-7.53x10(-5)X(1)X(2)-1.10X(1)(2)-1.043x10(-7)X(2)(2), where X(1), X(2), and Y are pH, specific energy input (kJ/kg TS), and DD, respectively. In a 2D contour plot describing the tendency of DD with respect to pH and specific energy input, it was clear that DD increased as pH increased, but it seemed that DD decreased when the specific energy input exceeded about 20,000kJ/kg TS. This phenomenon tells us that there exists a certain point where additional energy input is ineffective in achieving further disintegration. A synergetic disintegration effect was also found in the combined pretreatment, with lower specific energy input in ultrasonic pretreatment yielding higher synergetic effect. Finally, in order to see the combined pretreatment effect in continuous operation, the sludge pretreated with low intensity alkaline (pH 9)/ultrasonic (7500kJ/kg TS) treatment was fed to a 3 L of anaerobic sequencing batch reactor after 70 days of control operation. CH(4) production yield significantly increased from 81.9+/-4.5mL CH(4)/g COD(added) to 127.3+/-5.0mL CH(4)/g COD(added) by pretreatment, and

Cellulolytic Enzymes Production via Solid-State Fermentation: Effect of Pretreatment Methods on Physicochemical Characteristics of Substrate

Directory of Open Access Journals (Sweden)

Khushal Brijwani

2011-01-01

Full Text Available We investigated the effect of pretreatment on the physicochemical characteristics—crystallinity, bed porosity, and volumetric specific surface of soybean hulls and production of cellulolytic enzymes in solid-state fermentation of Trichoderma reesei and Aspergillus oryzae cultures. Mild acid and alkali and steam pretreatments significantly increased crystallinity and bed porosity without significant change inholocellulosic composition of substrate. Crystalline and porous steam-pretreated soybean hulls inoculated with T. reesei culture had 4 filter paper units (FPU/g-ds, 0.6 IU/g-ds β-glucosidase, and 45 IU/g-ds endocellulase, whereas untreated hulls had 0.75 FPU/g-ds, 0.06 IU/g-ds β-glucosidase, and 7.29 IU/g-ds endocellulase enzyme activities. In A. oryzae steam-pretreated soybean hulls had 47.10 IU/g-ds endocellulase compared to 30.82 IU/g-ds in untreated soybean hulls. Generalized linear statistical model fitted to enzyme activity data showed that effects of physicochemical characteristics on enzymes production were both culture and enzyme specific. The paper shows a correlation between substrate physicochemical properties and enzyme production.

The effect of pre-treatment parameters on the quality of glass-ceramic wasteforms for plutonium immobilisation, consolidated by hot isostatic pressing

Energy Technology Data Exchange (ETDEWEB)

Thornber, Stephanie M.; Heath, Paul G. [Immobilisation Science Laboratory, Department of Materials Science & Engineering, The University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield S1 3JD (United Kingdom); Da Costa, Gabriel P. [Immobilisation Science Laboratory, Department of Materials Science & Engineering, The University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield S1 3JD (United Kingdom); Department of Chemical Engineering & Petroleum Engineering, Universidade Federal Fluminense, Rua Passo da Patria 156, CEP 24210-240, Niteroi, RJ (Brazil); Stennett, Martin C. [Immobilisation Science Laboratory, Department of Materials Science & Engineering, The University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield S1 3JD (United Kingdom); Hyatt, Neil C., E-mail: n.c.hyatt@sheffield.ac.uk [Immobilisation Science Laboratory, Department of Materials Science & Engineering, The University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield S1 3JD (United Kingdom)

2017-03-15

Glass-ceramics with high glass fractions (70 wt%) were fabricated in stainless steel canisters by hot isostatic pressing (HIP), at laboratory scale. High (600 °C) and low (300 °C) temperature pre-treatments were investigated to reduce the canister evacuation time and to understand the effect on the phase assemblage and microstructure of the hot isostatically pressed product. Characterisation of the HIPed materials was performed using scanning electron microscopy (SEM), coupled with energy dispersive X-ray analysis (EDX) and powder X-ray diffraction (XRD). This analysis showed the microstructure and phase assemblage was independent of the variation in pre-treatment parameters. It was demonstrated that a high temperature pre-treatment of batch reagents, prior to the HIP cycle, is beneficial when using oxide precursors, in order to remove volatiles and achieve high quality dense materials. Sample throughput can be increased significantly by utilising a high temperature ex-situ calcination prior to the HIP cycle. Investigation of glass-ceramic wasteform processing utilising a glass frit precursor, produced a phase assemblage and microstructure comparable to that obtained using oxide precursors. The use of a glass frit precursor should allow optimised throughput of waste packages in a production facility, avoiding the need for a calcination pre-treatment required to remove volatiles from oxide precursors. - Highlights: • Optimisation of pre-treatment parameters for HIP glass-ceramics was investigated. • Entrained porosity was minimised by ex-situ bake-out of oxide precursors at 600 °C. • Phase assemblage and microstructure proved independent of bake-out parameters. • Use of glass-frit precursor further improved process s throughput and simplification.

The effect of pre-treatment parameters on the quality of glass-ceramic wasteforms for plutonium immobilisation, consolidated by hot isostatic pressing

International Nuclear Information System (INIS)

Thornber, Stephanie M.; Heath, Paul G.; Da Costa, Gabriel P.; Stennett, Martin C.; Hyatt, Neil C.

2017-01-01

Glass-ceramics with high glass fractions (70 wt%) were fabricated in stainless steel canisters by hot isostatic pressing (HIP), at laboratory scale. High (600 °C) and low (300 °C) temperature pre-treatments were investigated to reduce the canister evacuation time and to understand the effect on the phase assemblage and microstructure of the hot isostatically pressed product. Characterisation of the HIPed materials was performed using scanning electron microscopy (SEM), coupled with energy dispersive X-ray analysis (EDX) and powder X-ray diffraction (XRD). This analysis showed the microstructure and phase assemblage was independent of the variation in pre-treatment parameters. It was demonstrated that a high temperature pre-treatment of batch reagents, prior to the HIP cycle, is beneficial when using oxide precursors, in order to remove volatiles and achieve high quality dense materials. Sample throughput can be increased significantly by utilising a high temperature ex-situ calcination prior to the HIP cycle. Investigation of glass-ceramic wasteform processing utilising a glass frit precursor, produced a phase assemblage and microstructure comparable to that obtained using oxide precursors. The use of a glass frit precursor should allow optimised throughput of waste packages in a production facility, avoiding the need for a calcination pre-treatment required to remove volatiles from oxide precursors. - Highlights: • Optimisation of pre-treatment parameters for HIP glass-ceramics was investigated. • Entrained porosity was minimised by ex-situ bake-out of oxide precursors at 600 °C. • Phase assemblage and microstructure proved independent of bake-out parameters. • Use of glass-frit precursor further improved process s throughput and simplification.

Pretreatment and fermentation strategies to overcome the toxicity of acetic acid in hemicellulosic hydrolysates

DEFF Research Database (Denmark)

Mussatto, Solange I.

Acetic acid is one of the most important toxic compounds present in hemicellulosic hydrolysates. In order to overcome this problem, several strategies were studied for both biomass pretreatment and fermentation steps. Biomass deacetylation by mild alkaline pretreatment or using high pressure CO2...... where acetic acid can also be integrated as a valuable final product. For the fermentation step, it is well known that hemicellulosic hydrolysates usually need to be detoxified prior use as fermentation medium in order to improve the performance of the microorganism to convert sugars in the product...... of interest. Although detoxification improves the fermentability of hydrolysates, this additional step adds cost and complexity to the process and generates extra waste products. In this sense, the adaptation of the fermenting microorganism to increased concentrations of acetic acid can be considered...

Wet oxidation pretreatment of rape straw for ethanol production

International Nuclear Information System (INIS)

Arvaniti, Efthalia; Bjerre, Anne Belinda; Schmidt, Jens Ejbye

2012-01-01

Rape straw can be used for production of second generation bioethanol. In this paper we optimized the pretreatment of rape straw for this purpose using Wet oxidation (WO). The effect of reaction temperature, reaction time, and oxygen gas pressure was investigated for maximum ethanol yield via Simultaneous Saccharification and Fermentation (SSF). To reduce the water use and increase the energy efficiency in WO pretreatment features like recycling liquid (filtrate), presoaking of rape straw in water or recycled filtrate before WO, skip washing pretreated solids (filter cake) after WO, or use of whole slurry (Filter cake + filtrate) in SSF were also tested. Except ethanol yields, pretreatment methods were evaluated based on achieved glucose yields, amount of water used, recovery of cellulose, hemicellulose, and lignin. The highest ethanol yield obtained was 67% after fermenting the whole slurry produced by WO at 205 °C for 3 min with 12 bar of oxygen gas pressure and featured with presoaking in water. At these conditions after pre-treatment, cellulose and hemicellulose was recovered quantitatively (100%) together with 86% of the lignin. WO treatments of 2–3 min at 205–210 °C with 12 bar of oxygen gas produced higher ethanol yields and cellulose, hemicelluloses, and lignin recoveries, than 15 min WO treatment at 195 °C. Also, recycling filtrate and use of higher oxygen gas pressure reduced recovery of materials. The use of filtrate could be inhibitory for the yeast, but also reduced lactic acid formation in SSF. -- Highlights: ► Wet Oxidation pretreatment on rape straw for sugar and ethanol production. ► Variables were reaction time, temperature, and oxygen gas pressure. ► Also, other configurations for increase of water and energy efficiency. ► Short Wet oxidation pretreatment (2–3 min) produced highest ethanol yield. ► After these pretreatment conditions recovery of lignin in solids was 86%.

Biological pretreatment of corn stover with ligninolytic enzyme for high efficient enzymatic hydrolysis.

Science.gov (United States)

Wang, Feng-Qin; Xie, Hui; Chen, Wei; Wang, En-Tao; Du, Feng-Guang; Song, An-Dong

2013-09-01

Aiming at increasing the efficiency of transferring corn stover into sugars, a biological pretreatment was developed and investigated in this study. The protocol was characterized by the pretreatment with crude ligninolytic enzymes from Phanerochete chrysosporium and Coridus versicolor to break the lignin structure in corn stover, followed by a washing procedure to eliminate the inhibition of ligninolytic enzyme on cellulase. By a 2 d-pretreatment, sugar yield from corn stover hydrolysis could be increased by 50.2% (up to 323 mg/g) compared with that of the control. X-ray diffractometry and FT-IR analysis revealed that biological pretreatment could partially remove the lignin of corn stover, and consequently enhance the enzymatic hydrolysis efficiency of cellulose and hemeicellulose. In addition, the amount of microbial inhibitors, such as acetic acid and furfural, were much lower in biological pretreatment than that in acid pretreatment. This study provided a promising pretreatment method for biotransformation of corn stovers. Copyright © 2013 Elsevier Ltd. All rights reserved.

Comparison of aqueous ammonia and dilute acid pretreatment of bamboo fractions: Structure properties and enzymatic hydrolysis.

Science.gov (United States)

Xin, Donglin; Yang, Zhong; Liu, Feng; Xu, Xueru; Zhang, Junhua

2015-01-01

The effect of two pretreatments methods, aqueous ammonia (SAA) and dilute acid (DA), on the chemical compositions, cellulose crystallinity, morphologic change, and enzymatic hydrolysis of bamboo fractions (bamboo yellow, timber, green, and knot) was compared. Bamboo fractions with SAA pretreatment had better hydrolysability than those with DA pretreatment. High crystallinity index resulted in low hydrolysis yield in the conversion of SAA pretreated bamboo fractions, not DA pretreated fractions. The increase of cellulase loading had modestly positive effect in the hydrolysis of both SAA and DA pretreated bamboo fractions, while supplement of xylanase significantly increased the hydrolysis of the pretreated bamboo fractions, especially after SAA pretreatment. The results indicated that SAA pretreatment was more effective than DA pretreatment in conversion of bamboo fractions, and supplementation of xylanase was necessary in effective conversion of the SAA pretreated fractions into fermentable sugars. Copyright © 2014 Elsevier Ltd. All rights reserved.

Apple's dehydration by the irradiation pretreatment

International Nuclear Information System (INIS)

Fu Junjie; Chao Yan; Shen Weiqiao; Wang Jun

2001-01-01

"6"0 Co γ-ray irradiation was used as a pre-treatment method to dry the apple. The aim of this study was to discover the effect factor concerning the change of the apple cell structure which would affect the speed of drhydration and the relation between the speed of hot air dehydration and the irradiation dose. The results demonstrated that with the increasing of irradiation dose. The damage of apple's vacuole membrane increased. The positive correlation was shown in slice thickness and dehydration rate, the relation of the irradiation dose and the temperature of hot air was negatively correlated. The optimum of pre-treatment was gained for slice thickness, the irradiation dose and dry temperature of hot air. (authors)

Adsorption of β-glucosidases in two commercial preparations onto pretreated biomass and lignin

DEFF Research Database (Denmark)

Haven, Mai Østergaard; Jørgensen, Henning

2013-01-01

adsorbed strongly to lignin.The extent of adsorption of β-glucosidase from Cellic® CTec2 was affected by both type of biomass and pretreatment method. With approximately 65% of the β-glucosidases from Cellic® CTec2 adsorbed onto lignin from pretreated wheat straw, the activity of the β......Background: Enzyme recycling is a method to reduce the production costs for advanced bioethanol by lowering the overall use of enzymes. Commercial cellulase preparations consist of many different enzymes that are important for efficient and complete cellulose (and hemicellulose) hydrolysis...... commercial preparations (Novozym 188 and Cellic® CTec2) to substrates mimicking the components in pretreated wheat straw revealed that the Aspergillus niger β-glucosidase in Novozym 188 did not adsorb significantly to any of the components in pretreated wheat straw, whereas the β-glucosidase in Cellic® CTec2...

An evaluation of dilute acid and ammonia fiber explosion pretreatment for cellulosic ethanol production.

Science.gov (United States)

Mathew, Anil Kuruvilla; Parameshwaran, Binod; Sukumaran, Rajeev Kumar; Pandey, Ashok

2016-01-01

The challenge associated with cellulosic ethanol production is maximizing sugar yield at low cost. Current research is being focused to develop a pretreatment method to overcome biomass recalcitrance in an efficient way. This review is focused on two major pretreatments: dilute acid (DA) and ammonia fiber explosion (AFEX) pretreatment of corn stover and how these pretreatment cause morphological and chemical changes to corn stover in order to overcome the biomass recalcitrance. This review highlights the key differences of these two pretreatments based on compositional analysis, cellulose and its crystallinity, morphological changes, structural changes to lignin, enzymatic reactivity and enzyme adsorption onto pretreated solids and finally cellulosic ethanol production from the hydrolysate of DA and AFEX treated corn stover. Each stage of the process, AFEX pretreated corn stover was superior to DA treated corn stover. Copyright © 2015 Elsevier Ltd. All rights reserved.

Synergistic Effect of Trehalose and Saccharose Pretreatment on ...

African Journals Online (AJOL)

maintenance of lyophilized human red blood cell (RBC) quality. Methods: RBCs were pre-treated with trehalose and saccharose, and then lyophilized and .... different concentrations of trehalose and saccharose as described above.

Radioiodine therapy in patients with Graves' disease and the effects of prior carbimazole therapy.

Science.gov (United States)

Karyampudi, Arun; Hamide, Abdoul; Halanaik, Dhanapathi; Sahoo, Jaya Prakash; Kamalanathan, Sadishkumar

2014-09-01

The use of radioiodine as the first line of treatment in Graves' disease is restricted in India because of its limited availability and an unrealistic risk perception associated with it. Additionally, the effectiveness of radioiodine ablation in Graves' disease is influenced by many factors. Prior medical antithyroid therapy is one such important factor. To analyze the efficacy of low dose radioiodine therapy (5 mCi) in treatment of naive patients of Graves' disease in comparison to that in which it was already primed with an antithyroid drug, carbimazole. A non-randomized, interventional study conducted in the Department of Medicine and Endocrinology of a tertiary care institute in South India. The study had two groups; Group A (36 treatment naive, uncomplicated Graves' disease patients) and B (34 Graves' disease patients on carbimazole prior to radioiodine therapy). Both groups had baseline clinical, biochemical evaluation and were reassessed at 3 and 6 months for evaluating the clinical status for possible documentation of cure. The cure rate was 61.1% in drug naive group and 58.8% in pretreated group at 6 months following radioiodine (P = 0.845). Higher baseline 999m technicium (99m Tc) uptake, male gender, BMI and higher baseline free thyroxine (fT4) level predicted treatment failure following radioiodine therapy. Administration of carbimazole prior to low dose radioiodine therapy does not alter the efficacy of radioiodine. Low fixed dose (5 mCi) of radioactive iodine may be a safe and effective primary therapeutic option in Graves' disease patients pretreated with antithyroid drugs.

Ultrasonic and Thermal Pretreatments on Anaerobic Digestion of Petrochemical Sludge: Dewaterability and Degradation of PAHs

Science.gov (United States)

Zhou, Jun; Xu, Weizhong; Wong, Jonathan W. C.; Yong, Xiaoyu; Yan, Binghua; Zhang, Xueying; Jia, Honghua

2015-01-01

Effects of different pretreatment methods on sludge dewaterability and polycyclic aromatic hydrocarbons (PAHs) degradation during petrochemical sludge anaerobic digestion were studied. Results showed that the total biogas production volume in the thermal pretreatment system was 4 and 5 times higher than that in the ultrasound pretreatment and in the control system, and the corresponding volatile solid removal efficiencies reached 28%, 15%, and 8%. Phenanthrene, paranaphthalene, fluoranthene, benzofluoranthene, and benzopyrene removal rates reached 43.3%, 55.5%, 30.6%, 42.9%, and 41.7%, respectively, in the thermal pretreatment system, which were much higher than those in the ultrasound pretreatment and in the control system. Moreover, capillary suction time (CST) of sludge increased after pretreatment, and then reduced after 20 days of anaerobic digestion, indicating that sludge dewaterability was greatly improved after anaerobic digestion. The decrease of protein and polysaccharide in the sludge could improve sludge dewaterability during petrochemical sludge anaerobic digestion. This study suggested that thermal pretreatment might be a promising enhancement method for petrochemical sludge solubilization, thus contributing to degradation of the PAHs, biogas production, and improvement of dewaterability during petrochemical sludge anaerobic digestion. PMID:26327510

Enhancement of fermentative hydrogen production from green algal biomass of Thermotoga neapolitana by various pretreatment methods

Energy Technology Data Exchange (ETDEWEB)

Nguyen, Tam-Anh D.; Kim, Kyoung-Rok; Nguyen, Minh-Thu; Sim, Sang Jun [Department of Chemical Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Kim, Mi Sun [Bioenergy Research Center, Korea Institute of Energy Research, Daejeon 305-343 (Korea, Republic of); Kim, Donhue [Department of Biochemical Engineering, Dongyang Mirae College, Seoul 152-714 (Korea, Republic of)

2010-12-15

Biomass of the green algae has been recently an attractive feedstock source for bio-fuel production because the algal carbohydrates can be derived from atmospheric CO{sub 2} and their harvesting methods are simple. We utilized the accumulated starch in the green alga Chlamydomonas reinhardtii as the sole substrate for fermentative hydrogen (H{sub 2}) production by the hyperthermophilic eubacterium Thermotoga neapolitana. Because of possessing amylase activity, the bacterium could directly ferment H{sub 2} from algal starch with H{sub 2} yield of 1.8-2.2 mol H{sub 2}/mol glucose and the total accumulated H{sub 2} level from 43 to 49% (v/v) of the gas headspace in the closed culture bottle depending on various algal cell-wall disruption methods concluding sonication or methanol exposure. Attempting to enhance the H{sub 2} production, two pretreatment methods using the heat-HCl treatment and enzymatic hydrolysis were applied on algal biomass before using it as substrate for H{sub 2} fermentation. Cultivation with starch pretreated by 1.5% HCl at 121 C for 20 min showed the total accumulative H{sub 2} yield of 58% (v/v). In other approach, enzymatic digestion of starch by thermostable {alpha}-amylase (Termamyl) applied in the SHF process significantly enhanced the H{sub 2} productivity of the bacterium to 64% (v/v) of total accumulated H{sub 2} level and a H{sub 2} yield of 2.5 mol H{sub 2}/mol glucose. Our results demonstrated that direct H{sub 2} fermentation from algal biomass is more desirably potential because one bacterial cultivation step was required that meets the cost-savings, environmental friendly and simplicity of H{sub 2} production. (author)

Microalgal biomass pretreatment for bioethanol production: a review

Directory of Open Access Journals (Sweden)

Jesús Velazquez-Lucio

2018-03-01

Full Text Available Biofuels derived from microalgae biomass have received a great deal of attention owing to their high potentials as sustainable alternatives to fossil fuels. Microalgae have a high capacity of CO2 fixation and depending on their growth conditions, they can accumulate different quantities of lipids, proteins, and carbohydrates. Microalgal biomass can, therefore, represent a rich source of fermentable sugars for third generation bioethanol production. The utilization of microalgal carbohydrates for bioethanol production follows three main stages: i pretreatment, ii saccharification, and iii fermentation. One of the most important stages is the pretreatment, which is carried out to increase the accessibility to intracellular sugars, and thus plays an important role in improving the overall efficiency of the bioethanol production process. Diverse types of pretreatments are currently used including chemical, thermal, mechanical, biological, and their combinations, which can promote cell disruption, facilitate extraction, and result in the modification the structure of carbohydrates as well as the production of fermentable sugars. In this review, the different pretreatments used on microalgae biomass for bioethanol production are presented and discussed. Moreover, the methods used for starch and total carbohydrates quantification in microalgae biomass are also briefly presented and compared.

Effects of low dose radiation pretreatment on radiation injuried brain's free radicle

International Nuclear Information System (INIS)

Xu Fuqi; Wang Cheng; Xie Hong; Tian Ye

2006-01-01

Objective: To investigate the effect of low dose radiation pretreatment on radiation in- juried brain's free radicle to provide some useful data of brain radiation injury protection. Methods: One hundred mGy was selected as the pretreatment does, 25 Gy was selected as the challenge does. Experiment rats were divided into three groups randomly, group one as simple group:the group irradiated without exposing to pre-irradiation; group two as 6 h-group: the group irradiated with LDR pretreatment 6 h before exposing to 25 Gy irradiation; group three as 24 h-group:the group irradiated with LDR pretreatment 24 h before 25 Gy irradiation. The observation was done 6 hour's after irradiation, the effect of LDR pretreatment on increasing activity of the superoxide dismutase(SOD) and the content of malondialdehyde(MDA) after the brain tissue homogenate were detected. Results: Com- pared with the simple group, the group with LDR pretreatment showed increasing of SOD and decreasing of MDA at the 6th hour after 25Gy irradiation. In addition, there was no difference between the 6 h-group and the 24 h-group. Conclusion: LDR pretreatment can increase SOD and decrease MDA in some period. It could infer that the suitable LDR pretreatment could play a protective role in the brain radiation injury. (authors)

Changes in feedwater organic matter concentrations based on intake type and pretreatment processes at SWRO facilities, Red Sea, Saudi Arabia

KAUST Repository

Dehwah, Abdullah

2015-03-01

Transparent exopolymer particles (TEP), natural organic matter, and bacterial concentrations in feedwater are important factors that can lead to membrane biofouling in seawater reverse osmosis (SWRO) systems. Two methods for controlling these concentrations in the feedwater prior to pretreatment have been suggested; use of subsurface intake systems or placement of the intake at a greater depth in the sea. These proposed solutions were tested at two SWRO facilities located along the Red Sea of Saudi Arabia. A shallow well intake system was very effective in reducing the algae and bacterial concentrations and somewhat effective in reducing TEP concentrations. An intake placed at a depth of 9. m below the surface was found to have limited impact on improving water quality compared to a surface intake. The algae and bacteria concentration in the feedwater (deep) was lower compared to the surface seawater, but the overall TEP concentration was higher. Bacteria and TEP measurements made in the pretreatment process train in the plant and after the cartridge filters suggest that regrowth of bacteria is occurring within the cartridge filters.

Changes in feedwater organic matter concentrations based on intake type and pretreatment processes at SWRO facilities, Red Sea, Saudi Arabia

KAUST Repository

Dehwah, Abdullah; Li, Sheng; Almashharawi, Samir; Winters, Harvey; Missimer, Thomas M.

2015-01-01

Transparent exopolymer particles (TEP), natural organic matter, and bacterial concentrations in feedwater are important factors that can lead to membrane biofouling in seawater reverse osmosis (SWRO) systems. Two methods for controlling these concentrations in the feedwater prior to pretreatment have been suggested; use of subsurface intake systems or placement of the intake at a greater depth in the sea. These proposed solutions were tested at two SWRO facilities located along the Red Sea of Saudi Arabia. A shallow well intake system was very effective in reducing the algae and bacterial concentrations and somewhat effective in reducing TEP concentrations. An intake placed at a depth of 9. m below the surface was found to have limited impact on improving water quality compared to a surface intake. The algae and bacteria concentration in the feedwater (deep) was lower compared to the surface seawater, but the overall TEP concentration was higher. Bacteria and TEP measurements made in the pretreatment process train in the plant and after the cartridge filters suggest that regrowth of bacteria is occurring within the cartridge filters.

Testability evaluation using prior information of multiple sources

Institute of Scientific and Technical Information of China (English)

Wang Chao; Qiu Jing; Liu Guanjun; Zhang Yong

2014-01-01

Testability plays an important role in improving the readiness and decreasing the life-cycle cost of equipment. Testability demonstration and evaluation is of significance in measuring such testability indexes as fault detection rate (FDR) and fault isolation rate (FIR), which is useful to the producer in mastering the testability level and improving the testability design, and helpful to the consumer in making purchase decisions. Aiming at the problems with a small sample of testabil-ity demonstration test data (TDTD) such as low evaluation confidence and inaccurate result, a test-ability evaluation method is proposed based on the prior information of multiple sources and Bayes theory. Firstly, the types of prior information are analyzed. The maximum entropy method is applied to the prior information with the mean and interval estimate forms on the testability index to obtain the parameters of prior probability density function (PDF), and the empirical Bayesian method is used to get the parameters for the prior information with a success-fail form. Then, a parametrical data consistency check method is used to check the compatibility between all the sources of prior information and TDTD. For the prior information to pass the check, the prior credibility is calculated. A mixed prior distribution is formed based on the prior PDFs and the corresponding credibility. The Bayesian posterior distribution model is acquired with the mixed prior distribution and TDTD, based on which the point and interval estimates are calculated. Finally, examples of a flying control system are used to verify the proposed method. The results show that the proposed method is feasible and effective.

Ultrasonic pretreatment of woodchips for the conversion of cellulose to glucose for bioethanol production

International Nuclear Information System (INIS)

Tutun Nugraha; Rettyana Ayuputri; Mohammad Ihsan

2010-01-01

In this study, lignocellulosic biomass i.e. the woodchips of Albacia tree (Paraserianthes falcataria) were given different pretreatment methods, i.e. chemical (acid) and physical (ultrasonic). The pretreatment was given in order to convert the cellulose to glucose for the production of bioethanol. 1 % H_2SO_4 was applied for the acid pretreatment. Ultrasound pretreatment was carried out at varied time (10, 20 and 30 minutes) at 600 W, 20 khz before or after the acid pretreatment. Enzymatic attack of the pretreated sample was also applied to enhance the saccharification process of cellulose. The objective of the research was to determine the most effective ultrasonic duration and the best combination of method for enzymatic hydrolysis of the woodchips. The data showed that the highest yield of glucose was achieved at 20 minutes ultrasonic time. It was also found that substantial amount of hydrolysis of cellulose to glucose occur during the ultrasonic stage even without the presence of acid or cellulose enzyme. It is likely that the highly energetic ultrasonic process alone could assist in enhancing rate of hydrolysis of lignocellulosic cellulose into glucose. (author)

Comparison of Microwave and Ozonolysis Effect as Pretreatment on Sugarcane Bagasse Enzymatic Hydrolysis

Directory of Open Access Journals (Sweden)

N Eqra

2015-03-01

Full Text Available Bioethanol production from agricultural residues is one of the promising methods. Pretreatment is the most important step in this type of bioethanol production. In this study, the saccharification percentage of sugarcane bagasse was investigated after two types of pretreatments including ozone steaming and microwave. Microwave pretreatment was studied with two factors of microwave radiation (170, 450, and 850 w and microwave duration (2, 6, and 10 min. The ozonolysis (ozone steaming pretreatment was surveyed with two factors of moisture content of bagasse (30, 40, and 50% and ozonolysis time (1.5, 2.5, 3.5, and 4.5 hr. After hydrolysis, the Saccharification percentage of sugarcane bagasse increased to 57.2% and 67.06% with microwave and ozonolysis pretreatments, respectively; compare to 20.85% in non-ozonated bagasse. It can be concluded that the ozonolysis is the most effective pretreatment regarding to saccharification percentage of sugarcane bagasse.

Low temperature lignocellulose pretreatment: effects and interactions of pretreatment pH are critical for maximizing enzymatic monosaccharide yields from wheat straw

DEFF Research Database (Denmark)

Pedersen, Mads; Johansen, Katja S.; Meyer, Anne S.

2011-01-01

Background: The recent development of improved enzymes and pentose-using yeast for cellulosic ethanol processes calls for new attention to the lignocellulose pretreatment step. This study assessed the influence of pretreatment pH, temperature, and time, and their interactions on the enzymatic...... alkaline pretreatments. Alkaline pretreatments also solubilized most of the lignin. Conclusions: Pretreatment pH exerted significant effects and factor interactions on the enzymatic glucose and xylose releases. Quite extreme pH values were necessary with mild thermal pretreatment strategies (T...... glucose and xylose yields from mildly pretreated wheat straw in multivariate experimental designs of acid and alkaline pretreatments. Results: The pretreatment pH was the most significant factor affecting both the enzymatic glucose and xylose yields after mild thermal pretreatments at maximum 140 degrees...

Comparing two enhancing methods for improving kitchen waste anaerobic digestion: bentonite addition and autoclaved de-oiling pretreatment

DEFF Research Database (Denmark)

Zhang, Duojiao; Duan, Na; Tian, Hailin

2018-01-01

The effects of different enhancement methods, including adding bentonite (1.25%, w/w, wet substrate) and autoclaved de-oiling pretreatment (121 °C, 30 minutes), on the anaerobic digestion of kitchen waste (KW) were comparably studied. Mesophilic continuous stirred tank reactors were used under...... different organic loading rates (OLRs) of 1.11 to 1.84 gVS (volatile solid)L−1d−1 and two different hydraulic retention times (HRTs) (20 d and 25 d). In this study, two enhancement methods and extending HRT could prevent volatile fatty acids (VFA) accumulation and obtain a high methane production at low OLR...... design and process evaluation of a CSTR biogas plant treating with KW based on the laboratory experiment was stated....

Replacement of 5% of OPC by fly ash and APC residues from MSWI with electrodialytic pre-treatment

DEFF Research Database (Denmark)

Magro, Cátia; Kirkelund, Gunvor Marie; Guedes, Paula

2016-01-01

as pre-treatment prior to incorporation in mortar, aiming to stabilize and remove HM and chlorides. Eight ED experiments were performed for 7 days with a L/S ratio of 3.5. The number of compartments (2 or 3) and current density (0.1 or 1.0 mA cm-2) varied. After ED treatment the heavy metals left...... in the ash were not leached to the same extent as in the original ash. In mortar 5% of Ordinary Portland Cement was replaced by FA and APC residues (raw and ED upgraded). The studied parameters: compressive strength, HM leachability, and Cl content. The ED pre-treatment resulted in a decrease in both...

Bioluminescence-Based Method for Measuring Assimilable Organic Carbon in Pretreatment Water for Reverse Osmosis Membrane Desalination ▿

Science.gov (United States)

Weinrich, Lauren A.; Schneider, Orren D.; LeChevallier, Mark W.

2011-01-01

A bioluminescence-based assimilable organic carbon (AOC) test was developed for determining the biological growth potential of seawater within the reverse osmosis desalination pretreatment process. The test uses Vibrio harveyi, a marine organism that exhibits constitutive luminescence and is nutritionally robust. AOC was measured in both a pilot plant and a full-scale desalination plant pretreatment. PMID:21148685

Promise of combined hydrothermal/chemical and mechanical refining for pretreatment of woody and herbaceous biomass.

Science.gov (United States)

Kim, Sun Min; Dien, Bruce S; Singh, Vijay

2016-01-01

Production of advanced biofuels from woody and herbaceous feedstocks is moving into commercialization. Biomass needs to be pretreated to overcome the physicochemical properties of biomass that hinder enzyme accessibility, impeding the conversion of the plant cell walls to fermentable sugars. Pretreatment also remains one of the most costly unit operations in the process and among the most critical because it is the source of chemicals that inhibit enzymes and microorganisms and largely determines enzyme loading and sugar yields. Pretreatments are categorized into hydrothermal (aqueous)/chemical, physical, and biological pretreatments, and the mechanistic details of which are briefly outlined in this review. To leverage the synergistic effects of different pretreatment methods, conducting two or more pretreatments consecutively has gained attention. Especially, combining hydrothermal/chemical pretreatment and mechanical refining, a type of physical pretreatment, has the potential to be applied to an industrial plant. Here, the effects of the combined pretreatment (combined hydrothermal/chemical pretreatment and mechanical refining) on energy consumption, physical structure, sugar yields, and enzyme dosage are summarized.

Comparison of gamma irradiation and steam explosion pretreatment for ethanol production from agricultural residues

International Nuclear Information System (INIS)

Wang, Ke-qin; Xiong, Xing-yao; Chen, Jing-ping; Chen, Liang; Su, Xiaojun; Liu, Yun

2012-01-01

It was evaluated the influence of gamma irradiation and steam explosion pretreatment on the components and the water-soluble sugars of rice straw. Compared with the steam explosion pretreated rice straw, cellucose, hemicellucose and lignin for irradiation pretreated rice sample were much more greatly degraded and the relative content of glucose was significantly enhanced from 6.58% to 47.44%. Interestingly, no glucuronide acid was detected in irradiation pretreated rice straw, while glucuronide acid with the content from 8.5 mg/g to 9.2 mg/g was obtained in steam explosion pretreated sample. Followed by enzymatic hydrolysis, higher concentration of reducing sugars (including glucose and xylose) of irradiation pretreated rice sample (90.3 mg/g) was obtained, which was approximately 2.4- and 1.1- fold higher of the unpretreated (37.2 mg/g) and of steam explosion pretreated sample (85.4 mg/g). To further verify the effectiveness of irradiation pretreatment, characterizations of rice straw, corn stalk and bagasse by an integrated process of dilute acid/enzymatic hydrolysis and irradiation pretreatment were also investigated. -- Highlights: ► We compare irradiation and steam explosion pretreatments for bioethanol production. ► We examine changes in compositions of the components and the water-soluble sugars. ► No glucuronide acid was detected in gamma irradiation pretreated rice straw. ► We evaluate an integrated method of acid/enzyme-hydrolyzed irradiation pretreatment.

Effect of Support Pretreatment Temperature on the Performance of an Iron Fischer–Tropsch Catalyst Supported on Silica-Stabilized Alumina

Directory of Open Access Journals (Sweden)

Kamyar Keyvanloo

2018-02-01

Full Text Available The effect of support material pretreatment temperature, prior to adding the active phase and promoters, on Fischer–Tropsch activity and selectivity was explored. Four iron catalysts were prepared on silica-stabilized alumina (AlSi supports pretreated at 700 °C, 900 °C, 1100 °C or 1200 °C. Addition of 5% silica to alumina made the AlSi material hydrothermally stable, which enabled the unusually high support pretreatment temperatures (>900 °C to be studied. High-temperature dehydroxylation of the AlSi before impregnation greatly reduces FeO·Al2O3 surface spinel formation by removing most of the support-surface hydroxyl groups leading to more effectively carbided catalyst. The activity increases more than four-fold for the support calcined at elevated temperatures (1100–1200 °C compared with traditional support calcination temperatures of <900 °C. This unique pretreatment also facilitates the formation of ε′-Fe2.2C rather than χ-Fe2.5C on the AlSi support, which shows an excellent correlation with catalyst productivity.

Ensiling of wheat straw decreases the required temperature in hydrothermal pretreatment

DEFF Research Database (Denmark)

Ambye-Jensen, Morten; Thomsen, Sune Tjalfe; Kádár, Zsófia

2013-01-01

BACKGROUND: Ensiling is a well-known method for preserving green biomasses through anaerobic production of organic acids by lactic acid bacteria. In this study, wheat straw is subjected to ensiling in combination with hydrothermal treatment as a combined pretreatment method, taking advantage...... of the produced organic acids. RESULTS: Ensiling for 4 weeks was accomplished in a vacuum bag system after addition of an inoculum of Lactobacillus buchneri and 7% w/w xylose to wheat straw biomass at 35% final dry matter. Both glucan and xylan were preserved, and the DM loss after ensiling was less than 0...... increased.Subsequent enzymatic hydrolysis of the solid fractions showed that ensiling significantly improved the effect of pretreatment, especially at the lower temperatures of 170 and 180°C.The overall glucose yields after pretreatments of ensiled wheat straw were higher than for non-ensiled wheat straw...

The influence of different pretreatment methods on biogas production from Jatropha curcas oil cake.

Science.gov (United States)

Jabłoński, Sławomir Jan; Kułażyński, Marek; Sikora, Ilona; Łukaszewicz, Marcin

2017-12-01

Drought and pest resistance, together with high oil content in its seeds, make Jatropha curcas a good oil source for biodiesel. Oil cake from J. curcas is not suitable for animal feeding and thus may be profitably used for additional energy production by conversion into biogas; however, the anaerobic digestion process must be optimized to obtain good efficiency. We subjected oil cake to thermal and acidic pretreatment to deactivate protease inhibitors and partially hydrolyze phytate. We then digested the samples in batch conditions to determine the effects of pretreatment on biogas production. Thermal pretreatment changed the kinetics of anaerobic digestion and reduced protease inhibitor activity and the concentration of phytate; however, biogas production efficiency was not affected (0.281 m 3  kg -1 ). To evaluate the possibility of recirculating water for SSF hydrolysis, ammonium nitrogen recovery from effluent was evaluated by its precipitation in the form of struvite (magnesium ammonium phosphate).Concentration of ammonium ions was reduced by 53% (to 980 mg L -1 ). We propose a water-saving concept based on percolation of J. curcas cake using anaerobic digestion effluent and feeding that percolate into a methanogenic bioreactor. Copyright © 2016 Elsevier Ltd. All rights reserved.

Physicochemical pretreatments and hydrolysis of furfural residues via carbon-based sulfonated solid acid.

Science.gov (United States)

Ma, Bao Jun; Sun, Yuan; Lin, Ke Ying; Li, Bing; Liu, Wan Yi

2014-03-01

Potential commercial physicochemical pretreatment methods, NaOH/microwave and NaOH/ultrasound were developed, and the carbon-based sulfonated solid acid catalysts were prepared for furfural residues conversion into reducing sugars. After the two optimum pretreatments, both the content of cellulose increased (74.03%, 72.28%, respectively) and the content of hemicellulose (94.11%, 94.17% of removal rate, respectively) and lignin (91.75%, 92.09% of removal rate, respectively) decreased in furfural residues. The reducing sugar yields of furfural residues with the two physicochemical pretreatments on coal tar-based solid acid reached 33.94% and 33.13%, respectively, higher than that pretreated via NaOH alone (27%) and comparable to that pretreated via NaOH/H2O2 (35.67%). The XRD patterns, IR spectra and SEM images show microwave and ultrasound improve the pretreatment effect. The results demonstrate the carbon-based sulfonated solid acids and the physicochemical pretreatments are green, effective, low-cost for furfural residues conversion. Copyright © 2014 Elsevier Ltd. All rights reserved.

Testability evaluation using prior information of multiple sources

Directory of Open Access Journals (Sweden)

Wang Chao

2014-08-01

Full Text Available Testability plays an important role in improving the readiness and decreasing the life-cycle cost of equipment. Testability demonstration and evaluation is of significance in measuring such testability indexes as fault detection rate (FDR and fault isolation rate (FIR, which is useful to the producer in mastering the testability level and improving the testability design, and helpful to the consumer in making purchase decisions. Aiming at the problems with a small sample of testability demonstration test data (TDTD such as low evaluation confidence and inaccurate result, a testability evaluation method is proposed based on the prior information of multiple sources and Bayes theory. Firstly, the types of prior information are analyzed. The maximum entropy method is applied to the prior information with the mean and interval estimate forms on the testability index to obtain the parameters of prior probability density function (PDF, and the empirical Bayesian method is used to get the parameters for the prior information with a success-fail form. Then, a parametrical data consistency check method is used to check the compatibility between all the sources of prior information and TDTD. For the prior information to pass the check, the prior credibility is calculated. A mixed prior distribution is formed based on the prior PDFs and the corresponding credibility. The Bayesian posterior distribution model is acquired with the mixed prior distribution and TDTD, based on which the point and interval estimates are calculated. Finally, examples of a flying control system are used to verify the proposed method. The results show that the proposed method is feasible and effective.

Radiopaque marker motion during pre-treatment CBCT as a predictor of intra-fractional prostate movement

International Nuclear Information System (INIS)

Bernchou, Uffe; Brink, Carsten; Agergaard, Soeren N.

2013-01-01

The intra-fractional movement of the prostate constitutes a hindrance for the reduction of the planning target volume margin for prostate cancer patients. Monitoring the movement of the prostate during treatment is a promising but in most centres not feasible solution. However, the projection images of the pre-treatment cone-beam computed tomography (CBCT) provide information about the motion of the target immediately preceding the treatment. This motion information can be extracted from any standard CBCT scan which is available in many institutions. In this study we measure the motion of the prostate during the pre-treatment CBCT and investigate whether this motion is correlated with the intra-fractional movement of the prostate. Material and methods: Pre- and post-treatment CBCT scans were made during a number of the fractions (average 11 range 8-12) for 13 prostate cancer patients during the radiation treatment course. The displacement of the post-treatment CBCT scans relative to the pre-treatment position was used to assess the intra-fractional motion. Automated image analysis was used to track the 2D position of radiopaque markers in the projection images of the scans. The most probable 3D trajectory of the markers during the CBCT scan was estimated based on a probability density function which was established for each individual scan. Results: The accuracy of the tracking algorithm was found satisfactory and the motion of the markers during the CBCT scans was successfully extracted from the projection images. This motion was generally small and uncorrelated with the subsequent intra-fractional movement of the prostate. The correlation coefficients were - 0.05, 0.07, and - 0.05 in the LR, AP, and CC direction, respectively. Conclusion: It is tempting to exploit the pre-treatment CBCT to predict the intra-fractional movement of the prostate but, unfortunately, we have found no correlation between the intra-fractional movement and the motion of the prostate

1-Butyl-3-Methylimidazolium Chloride Pretreatment on Malaysia Lignocellulose Wastes

International Nuclear Information System (INIS)

Lee, L.P.; Nur Hasyareeda Hassan; Muhammad Rahimi Yusop

2015-01-01

Ionic liquids (ILs) are of great interest as potential solvents for the production of fuels from lignocellulose biomass which is a potential source of bio fuels. To study the effects of pretreatment, 1-butyl-3-methylimidazolium chloride ([B mim]Cl) was used to pretreat woody plants, kempas (Koompassia malaccensis) and jelutong (Dyera costulata), and non-woody plants, kenaf (Hibiscus cannabinus) and rice husk (Oryza sativa) at 120 degree Celsius for 24 h. Cellulose was regenerated by the addition of water. The cell wall composition and structure of the lignocellulose bio masses before and after the ILs pretreatment were observed and characterized using field emission scanning electron microscopy (FESEM), attenuated total reflectance fourier transform infrared (ATR FT-IR) spectroscopy, and X-ray diffraction (XRD). After the pretreatment, enzymatic hydrolysis was carried out to identify the total reducing sugars (TRS) yields using dinitrosalicylic acid (DNS) method. Regenerated lignocellulose bio masses resulted in high TRS yields compared to their counter-parts which are in agreement with the findings of FESEM, ATR FT-IR and XRD that exhibited regenerated cellulose were less crystalline and more amorphous upon IL pretreatment. Therefore, kempas and jelutong can be alternate sources for the bio fuels production. (author)

Cellulase digestibility of pretreated biomass is limited by cellulose accessibility.

Science.gov (United States)

Jeoh, Tina; Ishizawa, Claudia I; Davis, Mark F; Himmel, Michael E; Adney, William S; Johnson, David K

2007-09-01

Attempts to correlate the physical and chemical properties of biomass to its susceptibility to enzyme digestion are often inconclusive or contradictory depending on variables such as the type of substrate, the pretreatment conditions and measurement techniques. In this study, we present a direct method for measuring the key factors governing cellulose digestibility in a biomass sample by directly probing cellulase binding and activity using a purified cellobiohydrolase (Cel7A) from Trichoderma reesei. Fluorescence-labeled T. reesei Cel7A was used to assay pretreated corn stover samples and pure cellulosic substrates to identify barriers to accessibility by this important component of cellulase preparations. The results showed cellulose conversion improved when T. reesei Cel7A bound in higher concentrations, indicating that the enzyme had greater access to the substrate. Factors such as the pretreatment severity, drying after pretreatment, and cellulose crystallinity were found to directly impact enzyme accessibility. This study provides direct evidence to support the notion that the best pretreatment schemes for rendering biomass more digestible to cellobiohydrolase enzymes are those that improve access to the cellulose in biomass cell walls, as well as those able to reduce the crystallinity of cell wall cellulose.

GREET Pretreatment Module

Energy Technology Data Exchange (ETDEWEB)

Adom, Felix K. [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division; Dunn, Jennifer B. [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division; Han, Jeongwoo [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division

2014-09-01

A wide range of biofuels and biochemicals can be produced from cellulosic biomass via different pretreatment technologies that yield sugars. Process simulations of dilute acid and ammonia fiber expansion pretreatment processes and subsequent hydrolysis were developed in Aspen Plus for four lignocellulosic feedstocks (corn stover, miscanthus, switchgrass, and poplar). This processing yields sugars that can be subsequently converted to biofuels or biochemical. Material and energy consumption data from Aspen Plus were then compiled in a new Greenhouses Gases, Regulated Emissions, and Energy Use in Transportation (GREET^TM) pretreatment module. The module estimates the cradle-to-gate fossil energy consumption (FEC) and greenhouse gas (GHG) emissions associated with producing fermentable sugars. This report documents the data and methodology used to develop this module and the cradle-to-gate FEC and GHG emissions that result from producing fermentable sugars.

A blind deconvolution method based on L1/L2 regularization prior in the gradient space

Science.gov (United States)

Cai, Ying; Shi, Yu; Hua, Xia

2018-02-01

In the process of image restoration, the result of image restoration is very different from the real image because of the existence of noise, in order to solve the ill posed problem in image restoration, a blind deconvolution method based on L1/L2 regularization prior to gradient domain is proposed. The method presented in this paper first adds a function to the prior knowledge, which is the ratio of the L1 norm to the L2 norm, and takes the function as the penalty term in the high frequency domain of the image. Then, the function is iteratively updated, and the iterative shrinkage threshold algorithm is applied to solve the high frequency image. In this paper, it is considered that the information in the gradient domain is better for the estimation of blur kernel, so the blur kernel is estimated in the gradient domain. This problem can be quickly implemented in the frequency domain by fast Fast Fourier Transform. In addition, in order to improve the effectiveness of the algorithm, we have added a multi-scale iterative optimization method. This paper proposes the blind deconvolution method based on L1/L2 regularization priors in the gradient space can obtain the unique and stable solution in the process of image restoration, which not only keeps the edges and details of the image, but also ensures the accuracy of the results.

Processes for pretreating lignocellulosic biomass: A review

Energy Technology Data Exchange (ETDEWEB)

McMillan, J.D.

1992-11-01

This paper reviews existing and proposed pretreatment processes for biomass. The focus is on the mechanisms by which the various pretreatments act and the influence of biomass structure and composition on the efficacy of particular pretreatment techniques. This analysis is used to identify pretreatment technologies and issues that warrant further research.

Combination of ensiling and fungal delignification as effective wheat straw pretreatment

DEFF Research Database (Denmark)

Thomsen, Sune T.; Londono, Jorge E. G.; Ambye-Jensen, Morten

2016-01-01

straw (WS). This study was undertaken to assess whether a combination of forced ensiling with Lactobacillus buchneri and WRF treatment using a low cellulase fungus, Ceriporiopsis subvermispora, could produce a relevant pretreatment effect on WS for bioethanol and biogas production. Results......: A combination of the ensiling and WRF treatment induced efficient pretreatment of WS by reducing lignin content and increasing enzymatic sugar release, thereby enabling an ethanol yield of 66 % of the theoretical max on the WS glucan, i.e. a yield comparable to yields obtained with high-tech, large......-scale pretreatment methods. The pretreatment effect was reached with only a minor total solids loss of 5 % by weight mainly caused by the fungal metabolism. The combination of the biopretreatments did not improve the methane potential of the WS, but improved the initial biogas production rate significantly...

Bioethanol production: Pretreatment and enzymatic hydrolysis of softwood

Energy Technology Data Exchange (ETDEWEB)

Tengborg, Charlotte

2000-05-01

The enzymatic hydrolysis process can be used to produce bioethanol from softwood, which are the dominating raw material in the Northern hemisphere. This thesis deals with the development of the process focusing on the pretreatment and the enzymatic hydrolysis stages. The influence of pretreatment conditions on sugar yield, and the effect of inhibitors on the ethanol yield, were investigated for spruce and pine. The maximum yields of hemicellulose sugars and glucose were obtained under different pretreatment conditions. This indicates that two-stage pretreatment may be preferable. The added catalysts, H{sub 2}SO{sub 4} and SO{sub 2}, resulted in similar total sugar yields about 40 g/100 g dry raw material. However, the fermentability of SO{sub 2}-impregnated material was better. This pretreatment resulted in the formation of inhibitors to the subsequent process steps, e.g. sugar and lignin degradation products. The glucose yield in the enzymatic hydrolysis stage was affected by various parameters such as enzyme loading, temperature, pH, residence time, substrate concentration, and agitation. To decrease the amount of fresh water used and thereby waste water produced, the sugar-rich prehydrolysate from the pretreatment step was included in the enzymatic hydrolysis of the solid fraction, resulting in a reduction in the cellulose conversion of up to 36%. Different prehydrolysate detoxification methods, such as treatment with Ca(OH){sub 2}, laccase, and fermentation using yeast, were investigated. The latter was shown to be very efficient. The amount of fresh water used can be further reduced by recycling various process streams. This was simulated experimentally in a bench-scale process. A reduction in fresh water demand of 50% was obtained without any further negative effects on either hydrolysis or fermentation.

Scale-up and integration of alkaline hydrogen peroxide pretreatment, enzymatic hydrolysis, and ethanolic fermentation.

Science.gov (United States)

Banerjee, Goutami; Car, Suzana; Liu, Tongjun; Williams, Daniel L; Meza, Sarynna López; Walton, Jonathan D; Hodge, David B

2012-04-01

Alkaline hydrogen peroxide (AHP) has several attractive features as a pretreatment in the lignocellulosic biomass-to-ethanol pipeline. Here, the feasibility of scaling-up the AHP process and integrating it with enzymatic hydrolysis and fermentation was studied. Corn stover (1 kg) was subjected to AHP pretreatment, hydrolyzed enzymatically, and the resulting sugars fermented to ethanol. The AHP pretreatment was performed at 0.125 g H(2) O(2) /g biomass, 22°C, and atmospheric pressure for 48 h with periodic pH readjustment. The enzymatic hydrolysis was performed in the same reactor following pH neutralization of the biomass slurry and without washing. After 48 h, glucose and xylose yields were 75% and 71% of the theoretical maximum. Sterility was maintained during pretreatment and enzymatic hydrolysis without the use of antibiotics. During fermentation using a glucose- and xylose-utilizing strain of Saccharomyces cerevisiae, all of the Glc and 67% of the Xyl were consumed in 120 h. The final ethanol titer was 13.7 g/L. Treatment of the enzymatic hydrolysate with activated carbon prior to fermentation had little effect on Glc fermentation but markedly improved utilization of Xyl, presumably due to the removal of soluble aromatic inhibitors. The results indicate that AHP is readily scalable and can be integrated with enzyme hydrolysis and fermentation. Compared to other leading pretreatments for lignocellulosic biomass, AHP has potential advantages with regard to capital costs, process simplicity, feedstock handling, and compatibility with enzymatic deconstruction and fermentation. Biotechnol. Bioeng. 2012; 109:922-931. © 2011 Wiley Periodicals, Inc. Copyright © 2011 Wiley Periodicals, Inc.

Bromine pretreated chitosan for adsorption of lead

Indian Academy of Sciences (India)

Pollution by heavy metals like lead (II) is responsible for health hazards and environmental degradation. Adsorption is a prevalent method applied for removal of heavy metal pollutants from water. This study explored adsorption performances of 30% bromine pretreated chitosan for lead (II) abatement from water. Bromine ...

Simplifying sample pretreatment: application of dried blood spot (DBS) method to blood samples, including postmortem, for UHPLC-MS/MS analysis of drugs of abuse.

Science.gov (United States)

Odoardi, Sara; Anzillotti, Luca; Strano-Rossi, Sabina

2014-10-01

The complexity of biological matrices, such as blood, requires the development of suitably selective and reliable sample pretreatment procedures prior to their instrumental analysis. A method has been developed for the analysis of drugs of abuse and their metabolites from different chemical classes (opiates, methadone, fentanyl and analogues, cocaine, amphetamines and amphetamine-like substances, ketamine, LSD) in human blood using dried blood spot (DBS) and subsequent UHPLC-MS/MS analysis. DBS extraction required only 100μL of sample, added with the internal standards and then three droplets (30μL each) of this solution were spotted on the card, let dry for 1h, punched and extracted with methanol with 0.1% of formic acid. The supernatant was evaporated and the residue was then reconstituted in 100μL of water with 0.1% of formic acid and injected in the UHPLC-MS/MS system. The method was validated considering the following parameters: LOD and LOQ, linearity, precision, accuracy, matrix effect and dilution integrity. LODs were 0.05-1ng/mL and LOQs were 0.2-2ng/mL. The method showed satisfactory linearity for all substances, with determination coefficients always higher than 0.99. Intra and inter day precision, accuracy, matrix effect and dilution integrity were acceptable for all the studied substances. The addition of internal standards before DBS extraction and the deposition of a fixed volume of blood on the filter cards ensured the accurate quantification of the analytes. The validated method was then applied to authentic postmortem blood samples. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Effects of thermo-chemical pre-treatment on anaerobic biodegradability and hydrolysis of lignocellulosic biomass

NARCIS (Netherlands)

Fernandes, T.; Klaasse Bos, G.J.; Zeeman, G.; Sanders, J.P.M.; Lier, van J.B.

2009-01-01

The effects of different thermo-chemical pre-treatment methods were determined on the biodegradability and hydrolysis rate of lignocellulosic biomass. Three plant species, hay, straw and bracken were thermo-chemically pre-treated with calcium hydroxide, ammonium carbonate and maleic acid. After

Transformation of Starchy Lignocellulosic Biomass to Ethanol using Ragi Tapai Synergized with Microwave Irradiation Pretreatment

Directory of Open Access Journals (Sweden)

Kok Cheang Diong

2016-01-01

Full Text Available Ethanol production strategy was studied using multiple strain microbes from microwave irradiation (MI pretreated sago waste. Sago waste (SW was MI-pretreated for reducing sugars production using 2 heating media (water and sulfuric acid under pretreatment conditions including MI power, pretreatment duration, and solid loading. When water was used, the pretreatment parameters were optimized using Box-Behnken Design (BBD. However, gelatinized starch and charring of SW led to an insignificant quadratic model. To mitigate the gelatinization problem while determining the best MI pretreatment conditions, water was substituted by sulfuric acid using single factor method. The highest reducing sugar yield of 261.5 mg/g SW was achieved at 7.5% solid loading, 6 min pretreatment duration, and 300 W MI power. The effectiveness of the pretreatment was ascertained by field-emission scanning electron microscopy (FESEM and chemical-composition analysis. When fermenting MI-pretreated SW using ragi tapai, simultaneous saccharification of starch and ethanol production was evidenced from the sugar/ethanol profile. A resulted yield of 7.24 g ethanol/100 g SW confirmed the fermentability of MI-pretreated SW. The ethanol production was well fitted into the modified Gompertz model.

Example-driven manifold priors for image deconvolution.

Science.gov (United States)

Ni, Jie; Turaga, Pavan; Patel, Vishal M; Chellappa, Rama

2011-11-01

Image restoration methods that exploit prior information about images to be estimated have been extensively studied, typically using the Bayesian framework. In this paper, we consider the role of prior knowledge of the object class in the form of a patch manifold to address the deconvolution problem. Specifically, we incorporate unlabeled image data of the object class, say natural images, in the form of a patch-manifold prior for the object class. The manifold prior is implicitly estimated from the given unlabeled data. We show how the patch-manifold prior effectively exploits the available sample class data for regularizing the deblurring problem. Furthermore, we derive a generalized cross-validation (GCV) function to automatically determine the regularization parameter at each iteration without explicitly knowing the noise variance. Extensive experiments show that this method performs better than many competitive image deconvolution methods.

[Advances in research on mechanisms of seed pre-treatments.

Science.gov (United States)

Liu, Xu; Liu, Juan; Liu, Qian; Gao, Ya Ni; Wang, Quan Zhen

2016-11-18

Seeds play a vital role in nature and agro-ecosystems. The success of seed germination and the establishment of a normal seedling determine the propagation and survival of a plant species, but seed vigor is often seriously damaged because of seed aging, dormancy and the deterioration of natural habitat. Thus, exploring methods for improving germination quality is of great significance to ecology and the economy. Based on the latest international reports, seed pre-treatments are the most practical and effective methods for improving plant performance, increasing yields and enhancing stress resistance. This review provided a summary of the current pre-sowing treatment technologies and the physiological and biochemical responses of plants to these methods by addressing gene expression, cytological effects, enzyme system activities, material and energy metabolism, antioxidation mechanisms and signal transduction pathways. We also interpreted the mechanisms of the seed pre-treatment methods from aspects of seed germination acceleration and stress resistance enhancement. The bottleneck in seed pre-treatments at the cytological and molecular levels and the problems involved in their application were also discussed. Thus far, most studies had largely focused on the partial reaction alterations of plant biochemistry and enzyme activities, and they had generally been characterized by a lack of systematic and holistic study for applications to crop production. Finally, we proposed an outlook for further study in an attempt to provide a prospective and scientific reference for plant germplasm conservation, high-efficiency organic agriculture development and ecological environment re-construction.

The effect of pretreatment with fluoride on the tensile strength of orthodontic bonding

International Nuclear Information System (INIS)

Wang, W.N.; Sheen, D.H.

1991-01-01

White spot decalcifications and caries occurring adjacent to bonded orthodontic brackets have long been a concern to orthodontists. One procedure suggested to overcome this problem is fluoride treatment prior to bonding. The purpose of this study was to compare the tensile bond strength of orthodontic self-cured resin from Concise on teeth rinsed 4 minutes in 1.23% APF with untreated controls. Measurements were made on an Instron machine. Debonding interfaces were observed with a scanning electron microscope and energy dispersive x-ray spectrometry. Distributions were calculated. The tensile bond strengths of the fluoride-treated teeth and the untreated teeth were not significantly different. The debonding interfaces between resin and bracket base, within the resin itself, and between enamel and resin were similar in the two experimental groups. However, greater enamel detachment was seen within the fluoride pretreatment group. So while fluoride pretreatment does not significantly affect tensile bond strength, it may cause enamel detachment after debonding

Surface characterization and chemical analysis of bamboo substrates pretreated by alkali hydrogen peroxide.

Science.gov (United States)

Song, Xueping; Jiang, Yan; Rong, Xianjian; Wei, Wei; Wang, Shuangfei; Nie, Shuangxi

2016-09-01

The surface characterization and chemical analysis of bamboo substrates by alkali hydrogen peroxide pretreatment (AHPP) were investigated in this study. The results tended to manifest that AHPP prior to enzymatic and chemical treatment was potential for improving accessibility and reactivity of bamboo substrates. The inorganic components, organic solvent extractives and acid-soluble lignin were effectively removed by AHPP. X-ray photoelectron spectroscopy (XPS) analysis indicated that the surface of bamboo chips had less lignin but more carbohydrate after pre-treatment. Fiber surfaces became etched and collapsed, and more pores and debris on the substrate surface were observed with Scanning Electron Microscopy (SEM). Brenauer-Emmett-Teller (BET) results showed that both of pore volume and surface area were increased after AHPP. Although XRD analysis showed that AHPP led to relatively higher crystallinity, pre-extraction could overall enhance the accessibility of enzymes and chemicals into the bamboo structure. Copyright © 2016. Published by Elsevier Ltd.

Rapid pretreatment and detection of trace aflatoxin B1 in traditional soybean sauce.

Science.gov (United States)

Xie, Fang; Lai, WeiHua; Saini, Jasdeep; Shan, Shan; Cui, Xi; Liu, DaoFeng

2014-05-01

Soybean sauce, a traditional fermented food in China, has different levels of aflatoxin B1 pollution. Two kinds of direct and indirect immunomagnetic bead methods for the pretreatment of aflatoxin B1 were evaluated in this work. A method was established to detect aflatoxin B1 in soybean sauce using an immunomagnetic bead system for pretreatment and ELISA for quantification. The pretreatment method of immunomagnetic beads performed better compared with the conventional extraction and immunoaffinity column method. ELISA exhibited a good linear relationship at an aflatoxin B1 concentration of 0.05-0.3μg/kg (r(2)=0.9842). The average recoveries across spike levels varied from 0.5 to 7μg/kg were 83.6-104% with a relative standard deviation between 4.2% and 11.7%. With the advantages of rapid detection, easy operation, simple equipment, sensitivity, accuracy, and high recovery; this method can be well applied in the trace determination of aflatoxin B1 in soybean sauce samples. Copyright © 2013 Elsevier Ltd. All rights reserved.

Drying characteristics of osmotically pretreated cranberries : Energy and quality aspects

Energy Technology Data Exchange (ETDEWEB)

Grabowski, S.; Marcotte, M. [Agriculture and Agri-Food Canada, St. Hyacinthe, PQ (Canada). Food Research and Development Centre; Poirier, M.; Kudra, T. [Natural Resources Canada, Varennes, PQ (Canada). CANMET Energy Technology Centre

2002-06-01

This paper presents the results of a study in which osmotically pretreated cranberries were dried. The osmotic treatment included dehydration and sugar infusion. The process involved pretreating halved cranberries in a standard osmotic solution followed by freeze-drying, vacuum-drying and air-drying in various dryers, such as cabinet-air-through, fluid bed, pulsed fluid bed, and vibrated fluid bed dryers. The intent was to identify the best drying technology. The comparison criteria selected were energy consumption and product quality. Product quality for freeze-dried berries was quantified based on anthocyanins content, rehydration ratio, color, and taste. Unit heat consumption could be used for selecting the drying method, as all other drying methods yielded similar but slightly lower quality products. The highest energy efficiency was obtained with the vibrated fluid bed and the pulsed fluid bed. It was noted that drying rates were reduced during the second drying period when sugar was infused into the cranberries during osmotic pretreatment, but the total energy consumption was reduced by osmotic dehydration. 22 refs., 1 tab., 5 figs.

Simultaneous waste activated sludge disintegration and biological hydrogen production using an ozone/ultrasound pretreatment.

Science.gov (United States)

Yang, Shan-Shan; Guo, Wan-Qian; Cao, Guang-Li; Zheng, He-Shan; Ren, Nan-Qi

2012-11-01

This paper offers an effective pretreatment method that can simultaneously achieve excess sludge reduction and bio-hydrogen production from sludge self-fermentation. Batch tests demonstrated that the combinative use of ozone/ultrasound pretreatment had an advantage over the individual ozone and ultrasound pretreatments. The optimal condition (ozone dose of 0.158 g O(3)/g DS and ultrasound energy density of 1.423 W/mL) was recommended by response surface methodology. The maximum hydrogen yield was achieved at 9.28 mL H(2)/g DS under the optimal condition. According to the kinetic analysis, the highest hydrogen production rate (1.84 mL/h) was also obtained using combined pretreatment, which well fitted the predicted equation (the squared regression statistic was 0.9969). The disintegration degrees (DD) were limited to 19.57% and 46.10% in individual ozone and ultrasound pretreatments, while it reached up to 60.88% in combined pretreatment. The combined ozone/ultrasound pretreatment provides an ideal and environmental friendly solution to the problem of sludge disposal. Copyright © 2012 Elsevier Ltd. All rights reserved.

Varying prior information in Bayesian inversion

International Nuclear Information System (INIS)

Walker, Matthew; Curtis, Andrew

2014-01-01

Bayes' rule is used to combine likelihood and prior probability distributions. The former represents knowledge derived from new data, the latter represents pre-existing knowledge; the Bayesian combination is the so-called posterior distribution, representing the resultant new state of knowledge. While varying the likelihood due to differing data observations is common, there are also situations where the prior distribution must be changed or replaced repeatedly. For example, in mixture density neural network (MDN) inversion, using current methods the neural network employed for inversion needs to be retrained every time prior information changes. We develop a method of prior replacement to vary the prior without re-training the network. Thus the efficiency of MDN inversions can be increased, typically by orders of magnitude when applied to geophysical problems. We demonstrate this for the inversion of seismic attributes in a synthetic subsurface geological reservoir model. We also present results which suggest that prior replacement can be used to control the statistical properties (such as variance) of the final estimate of the posterior in more general (e.g., Monte Carlo based) inverse problem solutions. (paper)

Opportunities for utilization of non-conventional energy sources for biomass pretreatment.

Science.gov (United States)

Singh, Rawel; Krishna, Bhavya B; Kumar, Jitendra; Bhaskar, Thallada

2016-01-01

The increasing concerns over the depletion of fossil resources and its associated geo-political issues have driven the entire world to move toward sustainable forms of energy. Pretreatment is the first step in any biochemical conversion process for the production of valuable fuels/chemicals from lignocellulosic biomass to eliminate the lignin and produce fermentable sugars by hydrolysis. Conventional techniques have several limitations which can be addressed by using them in tandem with non-conventional methods for biomass pretreatment. Electron beam and γ (gamma)-irradiation, microwave and ultrasound energies have certain advantages over conventional source of energy and there is an opportunity that these energies can be exploited for biomass pretreatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

Pretreated of banana pseudo-stem as raw material for enzymatic hydrolysis and bioethanol production

Directory of Open Access Journals (Sweden)

Kusmiyati

2018-01-01

Full Text Available Development of alternative energy is needed to solve the energy problem, including bioethanol. Banana pseudo-stem is a lignocellulose material that can used to produce bioethanol. Banana pseudo-stem has 28.83% cellulose and 19.39% lignin. The amount of lignin will reduce by pretreatment process. Variations of pretreatment methods by autoclaving of banana-pseudo stem in a steam, 0.5N, 1N, 1.5N, 2N NaOH solutions for 90 minutes were employed. Then the preteated samples were further enzymatic hydrolysed for 24, 48, 72 hours. The fermentation method of simultaneous saccharification and fermentation (SSF was applied using cellulase enzyme and yeast of Saccharomyces cerevisiae for 120 hours. The variation of the pretreatment process by increasing of NaOH concentration solutions led to decreased the lignin content while increased in cellulose content. The lowest lignin content was 11.44% and the highest cellulose was 51.66%. The highest sugar content was 29.8 g/L (at pretreatment 2N NaOH solution, 72 hours hydrolysis. The highest bioethanol amount (4.32 g/L was produced from pretreated banana stem using 2N NaOH solution.

Method for aqueous gold thiosulfate extraction using copper-cyanide pretreated carbon adsorption

Science.gov (United States)

Young, Courtney; Melashvili, Mariam; Gow, Nicholas V

2013-08-06

A gold thiosulfate leaching process uses carbon to remove gold from the leach liquor. The activated carbon is pretreated with copper cyanide. A copper (on the carbon) to gold (in solution) ratio of at least 1.5 optimizes gold recovery from solution. To recover the gold from the carbon, conventional elution technology works but is dependent on the copper to gold ratio on the carbon.

Comparative data on effects of leading pretreatments and enzyme loadings and formulations on sugar

Energy Technology Data Exchange (ETDEWEB)

Wyman, Charles [Univ. of California, Riverside, CA (United States); Balan, Venkatech [Michigan State Univ., East Lansing, MI (United States); Dale, Bruce E. [Michigan State Univ., East Lansing, MI (United States); Elander, Richard [National Renewable Energy Lab. (NREL), Golden, CO (United States); Falls, Matthew [Texas A & M Univ., College Station, TX (United States); Hames, Bonnie [Ceres Corporation, Thousand Oaks, CA (United States); Holtzapple, Mark [Texas A & M Univ., College Station, TX (United States); Ladisch, Michael R. [Purdue Univ., West Lafayette, IN (United States); Lee, Y. Y. [Auburn Univ., AL (United States); Mosier, Nathan [Purdue Univ., West Lafayette, IN (United States); Pallapolu, Venkata R. [Auburn Univ., AL (United States); Shi, Jian [Univ. of California, Riverside, CA (United States); Warner, Ryan E. [Genencor, Palo Alto, CA (United States)

2011-06-16

Dilute sulfuric acid (DA), sulfur dioxide (SO2), liquid hot water (LHW), soaking in aqueous ammonia (SAA), ammonia fiber expansion (AFEX), and lime pretreatments were applied to Alamo, Dacotah, and Shawnee switchgrass. Application of the same analytical methods and material balance approaches facil-itated meaningful comparisons of glucose and xylose yields from combined pretreatment and enzymatic hydrolysis. Use of a common supply of cellulase, beta-glucosidase, and xylanase also eased comparisons. All pretreatments enhanced sugar recovery from pretreatment and subsequent enzymatic hydrolysis substantially compared to untreated switchgrass. Adding beta-glucosidase was effective early in enzy-matic hydrolysis while cellobiose levels were high but had limited effect on longer term yields at the enzyme loadings applied. Adding xylanase improved yields most for higher pH pretreatments where more xylan was left in the solids. Harvest time had more impact on performance than switchgrass variety, and microscopy showed changes in different features could impact performance by different pretreatments.

Enzymatic Saccharification and Ethanol Fermentation of Reed Pretreated with Liquid Hot Water

Directory of Open Access Journals (Sweden)

Jie Lu

2012-01-01

Full Text Available Reed is a widespread-growing, inexpensive, and readily available lignocellulosic material source in northeast China. The objective of this study is to evaluate the liquid hot water (LHW pretreatment efficiency of reed based on the enzymatic digestibility and ethanol fermentability of water-insoluble solids (WISs from reed after the LHW pretreatment. Several variables in the LHW pretreatment and enzymatic hydrolysis process were optimized. The conversion of glucan to glucose and glucose concentrations are considered as response variables in different conditions. The optimum conditions for the LHW pretreatment of reed area temperature of 180°C for 20min and a solid-to-liquid ratio of 1 : 10. These optimum conditions for the LHW pretreatment of reed resulted in a cellulose conversion rate of 82.59% in the subsequent enzymatic hydrolysis at 50°C for 72 h with a cellulase loading of 30 filter paper unit per gram of oven-dried WIS. Increasing the pretreatment temperature resulted in a higher enzymatic digestibility of the WIS from reed. Separate hydrolysis and fermentation of WIS showed that the conversion of glucan to ethanol reached 99.5% of the theoretical yield. The LHW pretreatment of reed is a suitable method to acquire a high recovery of fermentable sugars and high ethanol conversion yield.

Impact analysis of different chemical pre-treatments on colour of apple discs during drying process

Directory of Open Access Journals (Sweden)

Jasmina Lukinac

2009-01-01

Full Text Available The main purpose of this study was to compare colour changes of chemically pre-treated dried apple discs. Changes were observed by chromameter in L*a*b* colour model by using Minolta chromameter CR-400 and by image analysis system in RGB colour model. Apple discs variety "Gold Rush" were pre-treated and dried in laboratory tray drier at drying temperature 70 °C and at airflow velocity of 1.5 ms-1. Different chemical pre-treatments were applied on apple discs (dipping in 0.5% ascorbic acid solution; 0.3% L–cysteine solution; 0.1% 4–hexyl resorcinol solution and 1% sodium metabisulphite solution. Mean values of colour parameters, colour changes and correlation coefficients for apple discs were calculated for both colour models. The analysis showed statistically significant influence of pre-treatment method on total colour changes for both chosen colour models of dried apples. Calculated correlation coefficient between colour changes for used models was found to be 0.894. According to colour characteristics the best results were achieved when samples were pre-treated with 0.5% ascorbic acid solution. According to calculated results it was found that image analysis method as well as colorimetric method can be used to observe the colour changes on dried apple discs.

Microbial pretreatment of cotton stalks by Phanerochaete chrysosporium for bioethanol production

Science.gov (United States)

Shi, Jian

Lignocellulosic biomass has been recognized as a widespread, potentially low cost renewable source of mixed sugars for fermentation to fuel ethanol. Pretreatment, as the first step towards conversion of lignocellulose to ethanol, remains one of the main barriers to technical and commercial success of the processing technology. Existing pretreatment methods have largely been developed on the basis of physiochemical technologies which are considered relatively expensive and usually involve adverse environmental impacts. In this study, an environmentally benign alternative, microbial pretreatment using Phanerochaete chrysosporium, was explored to degrade lignin in cotton stalks and facilitate their conversion into ethanol. Two submerged liquid pretreatment techniques (SmC), shallow stationary and agitated cultivation, at three inorganic salt concentrations (no salts, modified salts without Mn2+, modified salts with Mn2+) were compared by evaluating their pretreatment efficiencies. Shallow stationary cultivation with no salt was superior to other pretreatment conditions and gave 20.7% lignin degradation along with 76.3% solids recovery and 29.0% carbohydrate availability over a 14 day period. The influence of substrate moisture content (65%, 75% and 80% M.C. wet-basis), inorganic salt concentration (no salts, modified salts without Mn2+ , modified salts with Mn2+) and culture time (0-14 days) on pretreatment effectiveness in solid state (SSC) systems was also examined. It was shown that solid state cultivation at 75% M.C. without salts was the most preferable pretreatment resulting in 27.6% lignin degradation, 71.1% solids recovery and 41.6% carbohydrate availability over a period of 14 days. A study on hydrolysis and fermentation of cotton stalks treated microbially using the most promising SmC (shallow stationary, no salts) and SSC (75% moisture content, no salts) methods resulted in no increase in cellulose conversion with direct enzyme application (10.98% and 3

Ultrasound pretreatment for enhanced biogas production from olive mill wastewater.

Science.gov (United States)

Oz, Nilgun Ayman; Uzun, Alev Cagla

2015-01-01

This study investigates applicability of low frequency ultrasound technology to olive mill wastewaters (OMWs) as a pretreatment step prior to anaerobic batch reactors to improve biogas production and methane yield. OMWs originating from three phase processes are characterized with high organic content and complex nature. The treatment of the wastewater is problematic and alternative treatment options should be investigated. In the first part of the study, OMW samples were subjected to ultrasound at a frequency of 20kHz with applied powers varying between 50 and 100W under temperature controlled conditions for different time periods in order to determine the most effective sonication conditions. The level of organic matter solubilization at ultrasound experiments was assessed by calculating the ratio of soluble chemical oxygen demand/total chemical oxygen demand (SCOD/TCOD). The results revealed that the optimum ultrasonic condition for diluted OMW is 20kHz, 0.4W/mL for 10min. The application of ultrasound to OMW increased SCOD/TCOD ratio from 0.59 to 0.79. Statistical analysis (Friedman's tests) show that ultrasound was significantly effective on diluted OMW (p0.05). For raw OMW, this increase has been found to be limited due to high concentration of suspended solids (SS). In the second part of the study, biogas and methane production rates of anaerobic batch reactor fed with the ultrasound pretreated OMW samples were compared with the results of control reactor fed with untreated OMW in order to determine the effect of sonication. A nonparametric statistical procedure, Mann-Whitney U test, was used to compare biogas and methane production from anaerobic batch reactors for control and ultrasound pretreated samples. Results showed that application of low frequency ultrasound to OMW significantly improved both biogas and methane production in anaerobic batch reactor fed with the wastewater (pbiogas and methane compared with the untreated one (control reactor). The

Effects of embryo induction media and pretreatments in isolated ...

African Journals Online (AJOL)

STORAGESEVER

2009-11-16

Nov 16, 2009 ... chemical + heat and also the effects of 5 embryo induction media (NPB-99, C17, ... Key words: Hexaploid wheat, haploid, isolated microspore culture, pretreatment, ..... this method is influenced by several mentioned factors.

Pretreatment of Miscanthus for hydrogen production by Thermotoga elfii

NARCIS (Netherlands)

Vrije, de T.; Haas, de G.G.; Tan, G.B.; Keijsers, E.R.P.; Claassen, P.A.M.

2002-01-01

Pretreatment methods for the production of fermentable substrates from Miscanthus, a lignocellulosic biomass, were investigated. Results demonstrated an inverse relationship between lignin content and the efficiency of enzymatic hydrolysis of polysaccharides. High delignification values were

Enzymatic conversion of pretreated biomass into fermentable sugars for biorefinery operation

Science.gov (United States)

Gao, Dahai

2011-12-01

Depleting petroleum reserves and potential climate change caused by fossil fuel consumption have attracted significant attention towards the use of alternative renewable resources for production of fuels and chemicals. Lignocellulosic biomass provides a plentiful resource for the sustainable production of biofuels and biochemicals and could serve as an important contributor to the world energy portfolio in the near future. Successful biological conversion of lignocellulosic biomass requires an efficient and economical pretreatment method, high glucose/xylose yields during enzymatic hydrolysis and fermentation of both hexose and pentose to ethanol. High enzyme loading is a major economic bottleneck for the commercial processing of pretreated lignocellulosic biomass to produce fermentable sugars. Optimizing the enzyme cocktail for specific types of pretreated biomass allows for a significant reduction in enzyme loading without sacrificing hydrolysis yield. Core glycosyl hydrolases were isolated and purified from various sources to help rationally optimize an enzyme cocktail to digest ammonia fiber expansion (AFEX) treated corn stover. The four core cellulases were endoglucanase I (EG I), cellobiohydrolase I (CBH I), cellobiohydrolase II (CBH II) and beta-Glucosidase (betaG). The two core hemicellulases were an endoxylanase (EX) and a beta-xylosidase (betaX). A diverse set of accessory hemicellulases from bacterial sources was found necessary to enhance the synergistic action of cellulases hydrolysing AFEX pretreated corn stover. High glucose (around 80%) and xylose (around 70%) yields were achieved with a moderate enzyme loading (˜20 mg protein/g glucan) using an in-house developed enzyme cocktail and this cocktail was compared to commercial enzyme. Studying the binding properties of cellulases to lignocellulosic substrates is critical to achieving a fundamental understanding of plant cell wall saccharification. Lignin auto-fluorescence and degradation products

Biorefining of wheat straw: accounting for the distribution of mineral elements in pretreated biomass by an extended pretreatment-severity equation.

Science.gov (United States)

Le, Duy Michael; Sørensen, Hanne R; Knudsen, Niels Ole; Schjoerring, Jan K; Meyer, Anne S

2014-01-01

Mineral elements present in lignocellulosic biomass feedstocks may accumulate in biorefinery process streams and cause technological problems, or alternatively can be reaped for value addition. A better understanding of the distribution of minerals in biomass in response to pretreatment factors is therefore important in relation to development of new biorefinery processes. The objective of the present study was to examine the levels of mineral elements in pretreated wheat straw in response to systematic variations in the hydrothermal pretreatment parameters (pH, temperature, and treatment time), and to assess whether it is possible to model mineral levels in the pretreated fiber fraction. Principal component analysis of the wheat straw biomass constituents, including mineral elements, showed that the recovered levels of wheat straw constituents after different hydrothermal pretreatments could be divided into two groups: 1) Phosphorus, magnesium, potassium, manganese, zinc, and calcium correlated with xylose and arabinose (that is, hemicellulose), and levels of these constituents present in the fiber fraction after pretreatment varied depending on the pretreatment-severity; and 2) Silicon, iron, copper, aluminum correlated with lignin and cellulose levels, but the levels of these constituents showed no severity-dependent trends. For the first group, an expanded pretreatment-severity equation, containing a specific factor for each constituent, accounting for variability due to pretreatment pH, was developed. Using this equation, the mineral levels could be predicted with R(2) > 0.75; for some with R(2) up to 0.96. Pretreatment conditions, especially pH, significantly influenced the levels of phosphorus, magnesium, potassium, manganese, zinc, and calcium in the resulting fiber fractions. A new expanded pretreatment-severity equation is proposed to model and predict mineral composition in pretreated wheat straw biomass.

Innovative pretreatment strategies for biogas production.

Science.gov (United States)

Patinvoh, Regina J; Osadolor, Osagie A; Chandolias, Konstantinos; Sárvári Horváth, Ilona; Taherzadeh, Mohammad J

2017-01-01

Biogas or biomethane is traditionally produced via anaerobic digestion, or recently by thermochemical or a combination of thermochemical and biological processes via syngas (CO and H 2 ) fermentation. However, many of the feedstocks have recalcitrant structure and are difficult to digest (e.g., lignocelluloses or keratins), or they have toxic compounds (such as fruit flavors or high ammonia content), or not digestible at all (e.g., plastics). To overcome these challenges, innovative strategies for enhanced and economically favorable biogas production were proposed in this review. The strategies considered are commonly known physical pretreatment, rapid decompression, autohydrolysis, acid- or alkali pretreatments, solvents (e.g. for lignin or cellulose) pretreatments or leaching, supercritical, oxidative or biological pretreatments, as well as combined gasification and fermentation, integrated biogas production and pretreatment, innovative biogas digester design, co-digestion, and bio-augmentation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Continual reassessment method for dose escalation clinical trials in oncology: a comparison of prior skeleton approaches using AZD3514 data.

Science.gov (United States)

James, Gareth D; Symeonides, Stefan N; Marshall, Jayne; Young, Julia; Clack, Glen

2016-08-31

The continual reassessment method (CRM) requires an underlying model of the dose-toxicity relationship ("prior skeleton") and there is limited guidance of what this should be when little is known about this association. In this manuscript the impact of applying the CRM with different prior skeleton approaches and the 3 + 3 method are compared in terms of ability to determine the true maximum tolerated dose (MTD) and number of patients allocated to sub-optimal and toxic doses. Post-hoc dose-escalation analyses on real-life clinical trial data on an early oncology compound (AZD3514), using the 3 + 3 method and CRM using six different prior skeleton approaches. All methods correctly identified the true MTD. The 3 + 3 method allocated six patients to both sub-optimal and toxic doses. All CRM approaches allocated four patients to sub-optimal doses. No patients were allocated to toxic doses from sigmoidal, two from conservative and five from other approaches. Prior skeletons for the CRM for phase 1 clinical trials are proposed in this manuscript and applied to a real clinical trial dataset. Highly accurate initial skeleton estimates may not be essential to determine the true MTD, and, as expected, all CRM methods out-performed the 3 + 3 method. There were differences in performance between skeletons. The choice of skeleton should depend on whether minimizing the number of patients allocated to suboptimal or toxic doses is more important. NCT01162395 , Trial date of first registration: July 13, 2010.

The isolation of nucleic acids from fixed, paraffin-embedded tissues-which methods are useful when?

DEFF Research Database (Denmark)

Gilbert, M Thomas P; Haselkorn, Tamara; Bunce, Michael

2007-01-01

. Cross-linking not only complicates isolation of nucleic acid but also introduces polymerase "blocks" during PCR. A wide variety of methods exists for the recovery of DNA and RNA from archival tissues, and although a number of previous studies have qualitatively compared the relative merits....... These include methods of pre-treating the samples prior to extraction, extraction and nucleic acid purification methods themselves, and a post-extraction enzymatic repair technique. We find that although many of the published methods have distinct positive effects on some characteristics of the nucleic acids...

Power ultrasound as a pretreatment to convective drying of mulberry (Morus alba L.) leaves: Impact on drying kinetics and selected quality properties.

Science.gov (United States)

Tao, Yang; Wang, Ping; Wang, Yilin; Kadam, Shekhar U; Han, Yongbin; Wang, Jiandong; Zhou, Jianzhong

2016-07-01

The effect of ultrasound pretreatment prior to convective drying on drying kinetics and selected quality properties of mulberry leaves was investigated in this study. Ultrasound pretreatment was carried out at 25.2-117.6 W/L for 5-15 min in a continuous mode. After sonication, mulberry leaves were dried in a hot-air convective dryer at 60 °C. The results revealed that ultrasound pretreatment not only affected the weight of mulberry leaves, it also enhanced the convective drying kinetics and reduced total energy consumption. The drying kinetics was modeled using a diffusion model considering external resistance and effective diffusion coefficient De and mass transfer coefficient hm were identified. Both De and hm during convective drying increased with the increase of acoustic energy density (AED) and ultrasound duration. However, De and hm increased slowly at high AED levels. Furthermore, ultrasound pretreatment had a more profound influence on internal mass transfer resistance than on external mass transfer resistance during drying according to Sherwood numbers. Regarding the quality properties, the color, antioxidant activity and contents of several bioactive compounds of dried mulberry leaves pretreated by ultrasound at 63.0 W/L for 10 min were similar to that of mulberry leaves without any pretreatments. Overall, ultrasound pretreatment is effective to shorten the subsequent drying time of mulberry leaves without damaging the quality of final product. Copyright © 2016 Elsevier B.V. All rights reserved.

Sample pretreatment for the determination of metal impurities in silicon wafer

International Nuclear Information System (INIS)

Chung, H. Y.; Kim, Y. H.; Yoo, H. D.; Lee, S. H.

1999-01-01

The analytical results obtained by microwave digestion and acid digestion methods for sample pretreatment to determine metal impurities in silicon wafer by inductively coupled plasma--mass spectrometry(ICP-MS) were compared. In order to decompose the silicon wafer, a mixed solution of HNO 3 and HF was added to the sample and the metal elements were determined after removing the silicon matrix by evaporating silicon in the form of Si-F. The recovery percentages of Ni, Cr and Fe were found to be 95∼106% for both microwave digestion and acid digestion methods. The recovery percentage of Cu obtained by the acid digestion method was higher than that obtained by the microwave digestion method. For Zn, however, the microwave digestion method gave better result than the acid digestion method. Fe was added to a silicon wafer using a spin coater. The concentration of Fe in this sample was determined by ICP-MS, and the same results were obtained in the two pretreatment methods

Reducing biomass recalcitrance via mild sodium carbonate pretreatment.

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Mirmohamadsadeghi, Safoora; Chen, Zhu; Wan, Caixia

2016-06-01

This study examined the effects of mild sodium carbonate (Na2CO3) pretreatment on enzymatic hydrolysis of different feedstocks (i.e., corn stover, Miscanthus, and switchgrass). The results showed that sodium carbonate pretreatment markedly enhanced the sugar yields of the tested biomass feedstocks. The pretreated corn stover, Miscanthus, and switchgrass gave the glucose yields of 95.1%, 62.3%, and 81.3%, respectively, after enzymatic hydrolysis. The above glucose yields of pretreated feedstocks were 2-4 times that of untreated ones. The pretreatment also enhanced the xylose yields, 4 times for corn stover and 20 times for both Miscanthus and switchgrass. Sodium carbonate pretreatment removed 40-59% lignin from the tested feedstocks while preserving most of cellulose (sodium carbonate pretreatment was effective for reducing biomass recalcitrance and subsequently improving the digestibility of lignocellulosic biomass. Copyright © 2016 Elsevier Ltd. All rights reserved.

The role of pre-treatment MRI in established cases of slipped capital femoral epiphysis

International Nuclear Information System (INIS)

Tins, Bernhard; Cassar-Pullicino, Victor; McCall, Iain

2009-01-01

Background: Slipped capital femoral epiphysis (SCFE) often results in functional impairment and premature osteoarthritis despite surgical treatment. Treatment decisions are commonly based on the clinical history and radiographic appearance. This study assesses the pre-treatment features of SCFE and correlates them to the clinical history to: (1) define the underlying pathological mechanisms; (2) correlate the morphological hip abnormalities with the clinical classifications; (3) identify specific magnetic resonance imaging (MRI) features that could carry prognostic implications for treatment approach and outcome. Methods: Clinical history and pre- and posttreatment radiographs and pre-treatment MRIs of 14 patients with 15 affected hips were reviewed. Alignment, impingement, fulcrum formation, remodelling, osteopenia, synovitis, joint effusion, bone marrow and soft tissue oedema and status of the physis and the periosteal sleeve were assessed and related to the clinical history, in particular history of trauma, duration of clinical symptoms and ability to bear weight. Results: Bone marrow oedema around the growth plate and joint effusion occurred in all patients. Synovitis occurred in 13/15 patients. 6 patients had a fall before presenting with SCFE. 5/6 had periarticular soft tissue oedema, complete disruption of the physis and partial periosteal sleeve disruption. 9 patients had no fall prior to presentation, physis and periost were intact in 7/9; periarticular oedema was not seen. 14/15 showed evidence of chronic remodelling. Despite an acute clinical history remodelling was present. A fulcrum-like alignment, impingement of the epiphysis on the metaphysis with a small area of physical contact, was seen in 8 patients, 6/8 had a prior fall. There was no case of avascular necrosis. Spontaneous reduction of SCFE occurred in 1 case, the only case without chronic remodelling. With MRI as gold standard radiographs underestimate the severity of SCFE. Conclusion

The role of pre-treatment MRI in established cases of slipped capital femoral epiphysis

Energy Technology Data Exchange (ETDEWEB)

Tins, Bernhard [Department of Radiology, Robert Jones and Agnes Hunt Orthopaedic and District Hospital, Oswestry, Shropshire SY 10 7 AG (United Kingdom)], E-mail: Bernhard.Tins@rjah.nhs.uk; Cassar-Pullicino, Victor; McCall, Iain [Department of Radiology, Robert Jones and Agnes Hunt Orthopaedic and District Hospital, Oswestry, Shropshire SY 10 7 AG (United Kingdom)

2009-06-15

Background: Slipped capital femoral epiphysis (SCFE) often results in functional impairment and premature osteoarthritis despite surgical treatment. Treatment decisions are commonly based on the clinical history and radiographic appearance. This study assesses the pre-treatment features of SCFE and correlates them to the clinical history to: (1) define the underlying pathological mechanisms; (2) correlate the morphological hip abnormalities with the clinical classifications; (3) identify specific magnetic resonance imaging (MRI) features that could carry prognostic implications for treatment approach and outcome. Methods: Clinical history and pre- and posttreatment radiographs and pre-treatment MRIs of 14 patients with 15 affected hips were reviewed. Alignment, impingement, fulcrum formation, remodelling, osteopenia, synovitis, joint effusion, bone marrow and soft tissue oedema and status of the physis and the periosteal sleeve were assessed and related to the clinical history, in particular history of trauma, duration of clinical symptoms and ability to bear weight. Results: Bone marrow oedema around the growth plate and joint effusion occurred in all patients. Synovitis occurred in 13/15 patients. 6 patients had a fall before presenting with SCFE. 5/6 had periarticular soft tissue oedema, complete disruption of the physis and partial periosteal sleeve disruption. 9 patients had no fall prior to presentation, physis and periost were intact in 7/9; periarticular oedema was not seen. 14/15 showed evidence of chronic remodelling. Despite an acute clinical history remodelling was present. A fulcrum-like alignment, impingement of the epiphysis on the metaphysis with a small area of physical contact, was seen in 8 patients, 6/8 had a prior fall. There was no case of avascular necrosis. Spontaneous reduction of SCFE occurred in 1 case, the only case without chronic remodelling. With MRI as gold standard radiographs underestimate the severity of SCFE. Conclusion

SBR treatment of olive mill wastewaters: dilution or pre-treatment?

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Farabegoli, G; Chiavola, A; Rolle, E

2012-01-01

The olive-oil extraction industry is an economically important activity for many countries of the Mediterranean Sea area, with Spain, Greece and Italy being the major producers. This activity, however, may represent a serious environmental problem due to the discharge of highly polluted effluents, usually referred to as 'olive mill wastewaters' (OMWs). They are characterized by high values of chemical oxygen demand (COD) (80-300 g/L), lipids, total polyphenols (TPP), tannins and other substances difficult to degrade. An adequate treatment before discharging is therefore required to reduce the pollutant load. The aim of the present paper was to evaluate performances of a biological process in a sequencing batch reactor (SBR) fed with pre-treated OMWs. Pre-treatment consisted of a combined acid cracking (AC) and granular activated carbon (GAC) adsorption process. The efficiency of the system was compared with that of an identical SBR fed with the raw wastewater only diluted. Combined AC and GAC adsorption was chosen to be used prior to the following biological process due to its capability of providing high removal efficiencies of COD and TPP and also appreciable improvement of biodegradability. Comparing results obtained with different influents showed that best performances of the SBR were obtained by feeding it with raw diluted OMWs (dOMWs) and at the lowest dilution ratio (1:25): in this case, the removal efficiencies were 90 and 76%, as average, for COD and TPP, respectively. Feeding the SBR with either the pre-treated or the raw dOMWs at 1:50 gave very similar values of COD reduction (74%); however, an improvement of the TPP removal was observed in the former case.

SONO-OXIDATIVE PRE-TREATMENT OF WASTE ACTIVATED SLUDGE BEFORE ANAEROBIC BIODEGRADATION

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S. Şahinkaya

Full Text Available Abstract The effects of sonication, potassium ferrate (K2FeO4 oxidation and their simultaneous combination (called "sono-oxidative pre-treatment" on chemical properties and anaerobic digestion of waste activated sludge (WAS were investigated and compared comprehensively. Based on chemical parameters, the optimum operating conditions were found to be 0.3 g K2FeO4/g total solids (TS dosage for 2-h individual K2FeO4 oxidation, 0.50 W/mL ultrasonic power density for 10-min individual sonication and, lastly, the combination of 2.5-min sonication at 0.75 W/mL ultrasonic power density with 2-h chemical oxidation at 0.3 g K2FeO4/g TS dosage for sono-oxidative pre-treatment. The disintegration efficiencies of these methods under the optimized conditions were in the following descending order: 37.8% for sono-oxidative pre-treatment > 26.3% for sonication > 13.1% for K2FeO4 oxidation. The influences of these methods on anaerobic biodegradability were tested with the biochemical methane potential assay. It was seen that the cumulative methane production increased by 9.2% in the K2FeO4 oxidation reactor, 15.8% in the sonicated reactor and 18.6% in the reactor with sono-oxidative pre-treatment, compared to the control (untreated reactor.

Iterated random walks with shape prior

DEFF Research Database (Denmark)

Pujadas, Esmeralda Ruiz; Kjer, Hans Martin; Piella, Gemma

2016-01-01

the parametric probability density function. Then, random walks is performed iteratively aligning the prior with the current segmentation in every iteration. We tested the proposed approach with natural and medical images and compared it with the latest techniques with random walks and shape priors......We propose a new framework for image segmentation using random walks where a distance shape prior is combined with a region term. The shape prior is weighted by a confidence map to reduce the influence of the prior in high gradient areas and the region term is computed with k-means to estimate....... The experiments suggest that this method gives promising results for medical and natural images....

Pretreatment Technologies of Lignocellulosic Materials in Bioethanol Production Process

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Mohamad Rusdi Hidayat

2013-06-01

Full Text Available Bioethanol is one type of biofuel that developed significantly. The utilization of bioethanol is not only limited for fuel, but also could be used as material for various industries such as pharmaceuticals, cosmetics, and food. With wide utilization and relatively simple production technology has made bioethanol as the most favored biofuel currently. The use of lignocellulosic biomass, microalgae, seaweeds, even GMO (Genetically modified organisms as substrates for bioethanol production has been widely tested. Differences in the materials eventually led to change in the production technology used. Pretreatment technology in the bioethanol production using lignocellulosic currently experiencing rapid development. It is a key process and crucial for the whole next steps. Based on the advantages and disadvantages from all methods, steam explotion and liquid hot water methods are the most promising  pretreatment technology available.

The characteristic changes of betung bamboo (Dendrocalamus asper pretreated by fungal pretreatment

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Widya Fatriasari

2014-05-01

Full Text Available Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 The fungal pretreatment effect on chemical structural and morphological changes of Betung Bamboo was evaluated based on its biomass components after being cultivated by white rot fungi, Trametes versicolor. Betung bamboo powder (15 g was exposed to liquid inoculum of white rot fungi and incubated at 270C for 15, 30 and 45 days. The treated samples were then characterized by FT-IR spectroscopy, X-Ray diffraction and SEM-EDS analyses. Cultivation for 30 days with 5 and 10% loadings retained greater selectivity compared to that of the other treatments. FTIR spectra demonstrated that the fungus affected the decreasing of functional group quantities without changing the functional groups. The decrease in intensity at wave number of 1246 cm-1 (guaiacyl of lignin was greater than that at wave number of 1328 cm-1 (deformation combination of syringyl and xylan after fungal treatment. X-ray analysis showed the pretreated samples had a higher crystallinity than the untreated ones which might be due to the cleavage of amorphous fractions of cellulose. The pretreated samples have more fragile than the untreated ones confirmed by SEM. Crystalline allomorph calculated by XRD analysis showed that fungus pretreatment for 30 days has transformed triclinic structure of cellulose to monoclinic structure.

Impact of Pretreatment and Drying Methods on Quality Attributes of Onion Shreds

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Nihar R. Sahoo

2015-01-01

Full Text Available Experiments were conducted on dry untreated onion shreds (2 mm thickness or treated with salt (5 % solution and potassium metabisulphite (0.5 % solution in convective drier at 50 °C ((46±4 % relative humidity (RH, 55 °C ((35±4 % RH, 60 °C ((28±4 % RH and 65 °C ((20±4 % RH, heat pump-assisted convective drier at 35 °C ((32±2 % RH, 40 °C ((26±2 % RH, 45 °C ((19±2 % RH and 50 °C ((15±2 % RH and microwave-assisted convective drier at four microwave power levels, i.e. 120, 240, 360 and 480 W. The quality parameters of the dried onion shreds, namely rehydration ratio, colour diff erence, pyruvic and ascorbic acid contents and sensory scores were evaluated. The quality of dehydrated onion shreds was observed to be comparatively better when treated in heat pump drier at 50 °C, followed by that in microwave-assisted convective drier at 240 W and 50 °C, and last in convective drier at 60 °C. The onion shreds pretreated with potassium metabisulphite retained better colour of the dried product irrespective of drying methods. Therefore, heat pump drying may be recommended as one of the best drying methods for onion shreds, because it maintains the fi nal product quality, which has practical importance for the food industry.

Metabolism of aspirin and procaine in mice pretreated with O-4-nitrophenyl methyl(phenyl)phosphinate or O-4-nitrophenyl diphenylphosphinate

International Nuclear Information System (INIS)

Joly, J.M.; Brown, T.M.

1986-01-01

Concentrations of [carboxyl- 14 C]procaine in blood of mice were increased threefold for 27 min by exposure to O-4-nitrophenyl diphenylphosphinate 2 hr prior to [carboxyl- 14 C]procaine injection ip, while there was no effect of O-4-nitrophenyl methyl(phenyl)phosphinate pretreatment. There was no effect of either organophosphinate on the primary hydrolysis of [acetyl-l- 14 C]aspirin when assessed by the expiration of [ 14 C]carbon dioxide; however, O-4-nitrophenyl diphenylphosphinate pretreatment produced transient increases in blood concentrations of both [carboxyl- 14 C]aspirin and [carboxyl- 14 C]salicylic acid following administration of [carboxyl- 14 C]aspirin. Liver carboxylesterase activity in O-4-nitrophenyl diphenylphosphinate pretreated mice was 11% of control activity. These results indicate the potential for drug interaction with O-4-nitrophenyl diphenylphosphinate but not with O-4-nitrophenyl methyl(phenyl)phosphinate. It appears that liver carboxylesterase activity has a minor role in hydrolysis of aspirin in vivo, but may be more important in procaine metabolism

Improving Gold Recovery from Artificial Preg-Robbing Ore by Pre-treatment using Blinding Agent and Resin-in-Leach

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Mohammad Zaki Mubarok

2016-08-01

Full Text Available In the present paper, the effectiveness of the use of blinding agents, ionic exchanger resins and the combination of them in improving gold extraction from simulated preg-robbing ore is discussed. The blinding agents used were kerosene, diesel oil and pine oil, while the ion exchange resins used were Lewatit Monoplus MP 800, Lewatit AF 5 and guanidine. Preg-robbing conditions were simulated by blending fine activated carbon with ore sample. The investigation results show that the presence of artificial carbonaceous materials at 2% (w/w in the gold ore significantly reduces gold recovery. Pretreatment of artificial preg-robbing ore prior to cyanidation by mixing with kerosene, diesel oil and pine oil for 0.5h improved gold recovery up to 25.4%. A combination of pre-treatment using blinding agent and a resin in leach (RIL test using Lewatit MP 800 resin demonstrated a synergistic effect that improves gold recovery up to a level of 99.5%,which is significantly higher than using activated carbon and without pretreatment.

Learning Using Dynamic and Static Visualizations: Students' Comprehension, Prior Knowledge and Conceptual Status of a Biotechnological Method

Science.gov (United States)

Yarden, Hagit; Yarden, Anat

2010-05-01

The importance of biotechnology education at the high-school level has been recognized in a number of international curriculum frameworks around the world. One of the most problematic issues in learning biotechnology has been found to be the biotechnological methods involved. Here, we examine the unique contribution of an animation of the polymerase chain reaction (PCR) in promoting conceptual learning of the biotechnological method among 12th-grade biology majors. All of the students learned about the PCR using still images ( n = 83) or the animation ( n = 90). A significant advantage to the animation treatment was identified following learning. Students’ prior content knowledge was found to be an important factor for students who learned PCR using still images, serving as an obstacle to learning the PCR method in the case of low prior knowledge. Through analysing students’ discourse, using the framework of the conceptual status analysis, we found that students who learned about PCR using still images faced difficulties in understanding some mechanistic aspects of the method. On the other hand, using the animation gave the students an advantage in understanding those aspects.

Hydrolysis of Rice Straw Pretreated by Na2SO3 Over Fe-resin/NaCl

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YANG Hui

2017-05-01

Full Text Available To increase the conversion of rice straw(RS and the yield of products, we employed three methods, which were ultrasonic wave, steam explosion and Na2SO3 pretreatment to pretreat RS(the treated RS noted as CS-RS, ZQ-RS and Na2SO3-RS, respectively and found that Na2SO3 treatment was the best pretreatment method based on XRD, SEM, elemental analysis and content of cellulose, hemicellulose and lignin. The conversion of Na2SO3-RS and the yield of total reducing sugar(TRS and levulinic acid(LA were 97.3%, 29.6% and 13.5%, respectively by 10% Fe-resin in 3.3% NaCl solution under 200 ℃.

Evaluation of chemical, thermobaric and thermochemical pre-treatment on anaerobic digestion of high-fat cattle slaughterhouse waste.

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Harris, Peter W; Schmidt, Thomas; McCabe, Bernadette K

2017-11-01

This work aimed to enhance the anaerobic digestion of fat-rich dissolved air flotation (DAF) sludge through chemical, thermobaric, and thermochemical pre-treatment methods. Soluble chemical oxygen demand was enhanced from 16.3% in the control to 20.84% (thermobaric), 40.82% (chemical), and 50.7% (thermochemical). Pre-treatment altered volatile fatty acid concentration by -64% (thermobaric), 127% (chemical) and 228% (thermochemical). Early inhibition was reduced by 20% in the thermochemical group, and 100% in the thermobaric group. Specific methane production was enhanced by 3.28% (chemical), 8.32% (thermobaric), and 8.49% (thermochemical) as a result of pre-treatment. Under batch digestion, thermobaric pre-treatment demonstrated the greatest improvement in methane yield with respect to degree of pre-treatment applied. Thermobaric pre-treatment was also the most viable for implementation at slaughterhouses, with potential for heat-exchange to reduce pre-treatment cost. Further investigation into long-term impact of pre-treatments in semi-continuous digestion experiments will provide additional evaluation of appropriate pre-treatment options for high-fat slaughterhouse wastewater. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Assessing the application and downstream effects of pulsed mode ultrasound as a pre-treatment for alum coagulation.

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Al-Juboori, Raed A; Aravinthan, Vasantha; Yusaf, Talal; Bowtell, Leslie

2016-07-01

The application of pulsed mode ultrasound (PMU) as a pre-treatment for alum coagulation was investigated at various alum dosages and pH levels. The effects of the treatments on turbidity and dissolved organic carbon (DOC) removal and residual Al were evaluated. Response surface methodology (RSM) was utilized to optimize the operating conditions of the applied treatments. The results showed that PMU pre-treatment increased turbidity and DOC removal percentages from maximum of 96.6% and 43% to 98.8% and 52%, respectively. It also helped decrease the minimum residual Al from 0.100 to 0.094 ppm. The multiple response optimization was carried out using the desirability function. A desirability value of >0.97 estimated respective turbidity removal, DOC removal and Al residual of 89.24%, 45.66% and ∼ 0.1 ppm for coagulation (control) and 90.61%, >55% and ∼ 0 for coagulation preceded by PMU. These figures were validated via confirmatory experiments. PMU pre-treatment increased total coliform removal from 80% to >98% and decreased trihalomethane formation potential (THMFP) from 250 to 200 ppb CH3Cl. Additionally, PMU application prior to coagulation improved the settleability of sludge due to the degassing effects. The results of this study confirms that PMU pre-treatment can significantly improve coagulation performance. Copyright © 2015 Elsevier B.V. All rights reserved.

The effect of thermal pre-treatment of titanium hydride (TiH2) powder in argon condition

Science.gov (United States)

Franciska P., L.; Erryani, Aprilia; Annur, Dhyah; Kartika, Ika

2018-04-01

Titanium hydride (TiH2) powders are used to enhance the foaming process in the formation of a highly porous metallic material with a cellular structure. But, the low temperature of hydrogen release is one of its problems. The present study, different thermal pre-treatment temperatures were employed to investigate the decomposition behavior of TiH2 to retard or delay a hydrogen gas release process during foaming. As a foaming agent, TiH2 was subjected to various heat treatments prior at 450 and 500°C during 2 hours in argon condition. To study the formation mechanism, the thermal behavior of titanium hydride and hydrogen release are investigated by thermogravimetric analysis (TGA) and differential thermal analysis (DTA). The morphology of pre-treated titanium hydride powders were examined using Scanning Electron Microscope (SEM) while unsure mapping and elemental composition of the pre-treated powders processed by Energy Dispersive Spectroscopy (EDS). To study the phase formation was characterized by X-ray diffraction analysis (XRD). In accordance with the results, an increase in pre-treatment temperature of TiH2 to higher degrees are changing the process of releasing hydrogen from titanium hydride powder. DTA/TGA results showed that thermal pre-treatment TiH2 at 450°C, released the hydrogen gas at 560°C in heat treatment when foaming process. Meanwhile, thermal pre-treatment in TiH2 at 500°C, released the hydrogen gas at 670°C when foaming process. There is plenty of direct evidence for the existence of oxide layers that showed by EDS analysis obtained in SEM. As oxygen is a light element and qualitative proof shows that the higher pre-treatment temperature produces more and thicker oxygen layers on the surface of the TiH2 powder particles. It might the thickness of oxide layer are different from different pre-treatment temperatures, which leading to the differences in the decomposition temperature. But from SEM result that oxidation of the powder does not

Detoxification of Corncob Acid Hydrolysate with SAA Pretreatment and Xylitol Production by Immobilized Candida tropicalis

Science.gov (United States)

Deng, Li-Hong; Tang, Yong; Liu, Yun

2014-01-01

Xylitol fermentation production from corncob acid hydrolysate has become an attractive and promising process. However, corncob acid hydrolysate cannot be directly used as fermentation substrate owing to various inhibitors. In this work, soaking in aqueous ammonia (SAA) pretreatment was employed to reduce the inhibitors in acid hydrolysate. After detoxification, the corncob acid hydrolysate was fermented by immobilized Candida tropicalis cell to produce xylitol. Results revealed that SAA pretreatment showed high delignification and efficient removal of acetyl group compounds without effect on cellulose and xylan content. Acetic acid was completely removed, and the content of phenolic compounds was reduced by 80%. Furthermore, kinetic behaviors of xylitol production by immobilized C. tropicalis cell were elucidated from corncob acid hydrolysate detoxified with SAA pretreatment and two-step adsorption method, respectively. The immobilized C. tropicalis cell showed higher productivity efficiency using the corncob acid hydrolysate as fermentation substrate after detoxification with SAA pretreatment than by two-step adsorption method in the five successive batch fermentation rounds. After the fifth round fermentation, about 60 g xylitol/L fermentation substrate was obtained for SAA pretreatment detoxification, while about 30 g xylitol/L fermentation substrate was obtained for two-step adsorption detoxification. PMID:25133211

Microbial pretreatment of corn stovers by solid-state cultivation of Phanerochaete chrysosporium for biogas production.

Science.gov (United States)

Liu, Shan; Wu, Shubiao; Pang, Changle; Li, Wei; Dong, Renjie

2014-02-01

The microbial pretreatment of corn stover and corn stover silage was achieved via the solid-state cultivation of Phanerochaete chrysosporium; pretreatment effects on the biodegradability and subsequent anaerobic production of biogas were investigated. The peak levels of daily biogas production and CH₄ yield from corn stover silage were approximately twice that of corn stover. Results suggested that ensiling was a potential pretreatment method to stimulate biogas production from corn stover. Surface morphology and Fourier-transform infrared spectroscopy analyses demonstrated that the microbial pretreatment of corn stover silage improved biogas production by 10.5 to 19.7% and CH4 yield by 11.7 to 21.2% because pretreatment could decrease dry mass loss (14.2%) and increase substrate biodegradability (19.9% cellulose, 32.4% hemicellulose, and 22.6% lignin). By contrast, the higher dry mass loss in corn stover (55.3%) after microbial pretreatment was accompanied by 54.7% cellulose, 64.0% hemicellulose, and 61.1% lignin degradation but did not significantly influence biogas production.

Crowdsourcing prior information to improve study design and data analysis.

Directory of Open Access Journals (Sweden)

Jeffrey S Chrabaszcz

Full Text Available Though Bayesian methods are being used more frequently, many still struggle with the best method for setting priors with novel measures or task environments. We propose a method for setting priors by eliciting continuous probability distributions from naive participants. This allows us to include any relevant information participants have for a given effect. Even when prior means are near-zero, this method provides a principle way to estimate dispersion and produce shrinkage, reducing the occurrence of overestimated effect sizes. We demonstrate this method with a number of published studies and compare the effect of different prior estimation and aggregation methods.

Iontophoresis of monomeric insulin analogues in vitro: effects of insulin charge and skin pretreatment.

Science.gov (United States)

Langkjaer, L; Brange, J; Grodsky, G M; Guy, R H

1998-01-23

The aim of this study was to investigate the influence of association state and net charge of human insulin analogues on the rate of iontophoretic transport across hairless mouse skin, and the effect of different skin pretreatments on said transport. No insulin flux was observed with anodal delivery probably because of degradation at the Ag/AgCl anode. The flux during cathodal iontophoresis through intact skin was insignificant for human hexameric insulin, and only low and variable fluxes were observed for monomeric insulins. Using stripped skin on the other hand, the fluxes of monomeric insulins with two extra negative charges were 50-100 times higher than that of hexameric human insulin. Introducing three additional charges led to a further 2-3-fold increase in flux. Wiping the skin gently with absolute alcohol prior to iontophoresis resulted in a 1000-fold increase in transdermal transport of insulin relative to that across untreated skin, i.e. to almost the same level as stripping the skin. The alcohol pretreatment reduced the electrical resistance of the skin, presumably by lipid extraction. In conclusion, monomeric insulin analogues with at least two extra negative charges can be iontophoretically delivered across hairless mouse skin, whereas insignificant flux is observed with human, hexameric insulin. Wiping the skin with absolute alcohol prior to iontophoresis gave substantially improved transdermal transport of monomeric insulins resulting in clinically relevant delivery rates for basal treatment.

PRETREATMENT OF LIGNOCELLULOSIC BIOMASS FOR ENZYMATIC HYDROLYSIS

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Doan Thai Hoa

2017-11-01

Full Text Available The cost of raw materials continues to be a limiting factor in the production of bio-ethanol from traditional raw materials, such as sugar and starch. At the same time, there are large amount of agricultural residues as well as industrial wastes that are of low or negative value (due to costs of current effluent disposal methods. Dilute sulfuric acid pretreatment of elephant grass and wood residues for the enzymatic hydrolysis of cellulose has been investigated in this study.    Elephant grass (agricultural residue and sawdust (Pulp and Paper Industry waste with a small particulate size were treated using different dilute sulfuric acid concentrations at a temperature  of 140-170°C within 0.5-3 hours. The appropriate pretreatment conditions give the highest yield of soluble saccharides and total reducing sugars.

Effect of ultrasonic pretreatment on purified water disinfection

International Nuclear Information System (INIS)

Simon Andreu, P.; Lardin Mifsut, C.; Vergara Romero, L.; Polo Canas, P. M.; Perez Sanchez, P.; Rancano Perez, A.

2009-01-01

Due to the importance of a suitable water disinfection in order to insure a pollutant effect minimization against environment, this work has been carried out to determine how can affect an ultrasonic pre-treatment upon disinfection step. It has been confirmed the ultrasonic disintegration of bacterial cells in treated water and disinfectant power of treatment by itself, which is not enough to be used as a single method in water disinfection. It has also been proved that from a technical and economical point of view the combination of UV and ultrasound improves the UV treatment performance. Finally, it has been detected that an ultrasonic pre-treatment increases chlorination effectiveness, however the high cost in this combination makes it unfeasible of industrial scale. (Author) 6 refs

Evaluation of Mucor indicus and Saccharomyces cerevisiae capability to ferment hydrolysates of rape straw and Miscanthus giganteus as affected by the pretreatment method.

Science.gov (United States)

Lewandowska, Małgorzata; Szymańska, Karolina; Kordala, Natalia; Dąbrowska, Aneta; Bednarski, Włodzimierz; Juszczuk, Andrzej

2016-07-01

Rape straw and Miscanthus giganteus was pretreated chemically with oxalic acid or sodium hydroxide. The pretreated substrates were hydrolyzed with enzymatic preparations of cellulase, xylanase and cellobiase. The highest concentration of reducing sugars was achieved after hydrolysis of M. giganteus pretreated with NaOH (51.53gdm(-3)). In turn, the highest yield of enzymatic hydrolysis determined based on polysaccharides content in the pretreated substrates was obtained in the experiments with M. giganteus and oxalic acid (99.3%). Rape straw and M. giganteus hydrolysates were fermented using yeast Saccharomyces cerevisiae 7, NRRL 978 or filamentous fungus Mucor rouxii (Mucor indicus) DSM 1191. The highest ethanol concentration was determined after fermentation of M. giganteus hydrolysate pretreated with NaOH using S. cerevisiae (1.92% v/v). Considering cellulose content in the pretreated solid, the highest degree of its conversion to ethanol (86.2%) was achieved after fermentation of the hydrolysate of acid-treated M. giganteus using S. cerevisiae. Copyright © 2016 Elsevier Ltd. All rights reserved.

Enhancing cellulose accessibility of corn stover by deep eutectic solvent pretreatment for butanol fermentation.

Science.gov (United States)

Xu, Guo-Chao; Ding, Ji-Cai; Han, Rui-Zhi; Dong, Jin-Jun; Ni, Ye

2016-03-01

In this study, an effective corn stover (CS) pretreatment method was developed for biobutanol fermentation. Deep eutectic solvents (DESs), consisted of quaternary ammonium salts and hydrogen donors, display similar properties to room temperature ionic liquid. Seven DESs with different hydrogen donors were facilely synthesized. Choline chloride:formic acid (ChCl:formic acid), an acidic DES, displayed excellent performance in the pretreatment of corn stover by removal of hemicellulose and lignin as confirmed by SEM, FTIR and XRD analysis. After optimization, glucose released from pretreated CS reached 17.0 g L(-1) and yield of 99%. The CS hydrolysate was successfully utilized in butanol fermentation by Clostridium saccharobutylicum DSM 13864, achieving butanol titer of 5.63 g L(-1) with a yield of 0.17 g g(-1) total sugar and productivity of 0.12 g L(-1)h(-1). This study demonstrates DES could be used as a promising and biocompatible pretreatment method for the conversion of lignocellulosic biomass into biofuel. Copyright © 2015 Elsevier Ltd. All rights reserved.

Hydrolysis of dilute acid-pretreated cellulose under mild hydrothermal conditions.

Science.gov (United States)

Chimentão, R J; Lorente, E; Gispert-Guirado, F; Medina, F; López, F

2014-10-13

The hydrolysis of dilute acid-pretreated cellulose was investigated in a conventional oven and under microwave heating. Two acids--sulfuric and oxalic--were studied. For both hydrothermal conditions (oven and microwave) the resultant total organic carbon (TOC) values obtained by the hydrolysis of the cellulose pretreated with sulfuric acid were higher than those obtained by the hydrolysis of the cellulose pretreated with oxalic acid. However, the dicarboxylic acid exhibited higher hydrolytic efficiency towards glucose. The hydrolysis of cellulose was greatly promoted by microwave heating. The Rietveld method was applied to fit the X-ray patterns of the resultant cellulose after hydrolysis. Oxalic acid preferentially removed the amorphous region of the cellulose and left the crystalline region untouched. On the other hand, sulfuric acid treatment decreased the ordering of the cellulose by partially disrupting its crystalline structure. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of TiB2 Pretreatment on Pt/TiB2 Catalyst Performance

International Nuclear Information System (INIS)

Huang, Zhen; Lin, Rui; Fan, Renjie; Fan, Qinbai; Ma, Jianxin

2014-01-01

Highlights: • We pretreated Titanium diboride by different acids and alkali. • We synthesis the Pt/as-pretreated TiB 2 catalysts by a colloid route. • We investigated the effects of TiB 2 Pretreatment on Pt/TiB 2 Catalyst Performance. • The BET surface area and defects on the surface have a close relationship with the deposition of Pt nanoparticles. - Abstract: Carbon support corrosion of traditional Pt/C catalyst is one of the major contributors causing poor durability of proton exchange membrane fuel cells (PEMFC). Titanium diboride (TiB 2 ) has high electrical conductivity and considerable chemical stability, which making it as a good candidate for catalyst support in PEMFC. In this work, TiB 2 was pretreated by different acid and alkali. The as-obtained samples were characterized by Ex-situ microscopy (ESM) and X-ray diffraction (XRD). The pore size distribution (PSD) was analyzed by using DFT method. The PSD shows distinct volume in mesopore regions (less than 50 nm). The TiB2 pretreated by H 2 O 2 shows the biggest BET surface area of 57 m 2 g −1 and its PSD focus on mesoporous (1.5-8 nm) region, which resulted to high dispersion and better loading of Pt particles. The Hydrogen oxidization reaction (HOR) and oxygen reduction reaction (ORR) activity was characterized by Rotating Disk Electrode (RDE). The Pt/TiB 2 prepared by H 2 O 2 -pretreated TiB 2 using the colloidal method showed better half-cell electrochemical performance. Facile synthetic for the development of Pt/TiB 2 catalysts was developed

Application of ceramic membranes for seawater reverse osmosis (SWRO) pre-treatment

KAUST Repository

Hamad, Juma

2013-05-30

Low-pressure (microfiltration/ultrafiltration (MF/UF)) membranes are being increasingly used as pre-treatment, prior to seawater reverse osmosis (SWRO). The objective of pre-treatment before reverse osmosis (RO) membranes is to remove undesirable and particulate fouling materials (algae, suspended and colloidal particles). Also, a pre-treatment barrier reduces organics and provides better feed water quality for RO membranes. MF and UF pre-treatment prior to SWRO provides Low Silt Density Index (SDI) values recommended for RO operation. Ceramic membranes are more attractive as they made of more chemically resistant materials, which allow for more stable operation and aggressive backwashing (BW) and cleaning. A pilot plant with a monolith ceramic MF membrane (0.1 μm pore size) from METAWATER was used to carry out the study. Red Sea water pumped from a distance of 700 m offshore from Thuwal (Kingdom of Saudi Arabia) was used as feed water. The pilot plant was operated automatically at constant flux of 150 LMH that involved BW, air flushing and forward flushing at the end of filtration cycle. Seawater permeates were used for hydraulic BW, while sodium hypochlorite, citric acid and sodium hydroxide were used for chemical cleaning (CIP) to restore the membrane permeability after use. Filtration cycles of 2.5 h were adopted for initial experiments. Aggressive BW flux of 1,800 LMH for 15 s, air flushing of 4 bars for 10 s and forward flushing of 300 LMH for 40 s were applied for regular membrane hydraulic cleaning. The increase of membrane resistances over time was monitored. Further studies were also performed by using Anopore ceramic membranes AAO100 (pore sizes of 0.1 μm) using a constant pressure bench-scale set-up. The feed water and permeate were analysed using an SDI unit, flow cytometre (FCM) and liquid chromatography with organic carbon detection (LC-OCD). The results showed that ceramic membrane filtration reduced the SDI15 of seawater from 6.1 to 2.1 which

Effect of pelleting on the recalcitrance and bioconversion of dilute-acid pretreated corn stover

Energy Technology Data Exchange (ETDEWEB)

Allison E Ray; Amber Hoover; Gary Gresham

2012-07-01

Background: Knowledge regarding the performance of densified biomass in biochemical processes is limited. The effects of densification on biochemical conversion are explored here. Methods: Pelleted corn stover samples were generated from bales that were milled to 6.35 mm. Low-solids acid pretreatment and simultaneous saccharification and fermentation were performed to evaluate pretreatment efficacy and ethanol yields achieved for pelleted and ground stover (6.35 mm and 2 mm) samples. Both pelleted and 6.35-mm ground stover were evaluated using a ZipperClave® reactor under high-solids, process-relevant conditions for multiple pretreatment severities (Ro), followed by enzymatic hydrolysis of the washed, pretreated solids. Results: Monomeric xylose yields were significantly higher for pellets (approximately 60%) than for ground formats (approximately 38%). Pellets achieved approximately 84% of theoretical ethanol yield (TEY); ground stover formats had similar profiles, reaching approximately 68% TEY. Pelleting corn stover was not detrimental to pretreatment efficacy for both low- and high-solids conditions, and even enhanced ethanol yields.

PET reconstruction via nonlocal means induced prior.

Science.gov (United States)

Hou, Qingfeng; Huang, Jing; Bian, Zhaoying; Chen, Wufan; Ma, Jianhua

2015-01-01

The traditional Bayesian priors for maximum a posteriori (MAP) reconstruction methods usually incorporate local neighborhood interactions that penalize large deviations in parameter estimates for adjacent pixels; therefore, only local pixel differences are utilized. This limits their abilities of penalizing the image roughness. To achieve high-quality PET image reconstruction, this study investigates a MAP reconstruction strategy by incorporating a nonlocal means induced (NLMi) prior (NLMi-MAP) which enables utilizing global similarity information of image. The present NLMi prior approximates the derivative of Gibbs energy function by an NLM filtering process. Specially, the NLMi prior is obtained by subtracting the current image estimation from its NLM filtered version and feeding the residual error back to the reconstruction filter to yield the new image estimation. We tested the present NLMi-MAP method with simulated and real PET datasets. Comparison studies with conventional filtered backprojection (FBP) and a few iterative reconstruction methods clearly demonstrate that the present NLMi-MAP method performs better in lowering noise, preserving image edge and in higher signal to noise ratio (SNR). Extensive experimental results show that the NLMi-MAP method outperforms the existing methods in terms of cross profile, noise reduction, SNR, root mean square error (RMSE) and correlation coefficient (CORR).

Effectiveness of a pre-treatment snack on the uptake of mass treatment for schistosomiasis in Uganda

DEFF Research Database (Denmark)

Muhumuza, Simon; Olsen, Annette; Katahoire, Anne

2014-01-01

-treatment snack on uptake of mass treatment.Methods and Findings:In a cluster randomized trial carried out in Jinja district, Uganda, 12 primary schools were randomized into two groups; one received education messages for schistosomiasis prevention for two months prior to mass treatment, while the other......, in addition to the education messages, received a pre-treatment snack shortly before mass treatment. Four weeks after mass treatment, uptake of praziquantel was assessed among a random sample of 595 children in the snack schools and 689 children in the non-snack schools as the primary outcome. The occurrence...... of side effects and the prevalence and mean intensity of Schistosoma mansoni infection were determined as the secondary outcomes. Uptake of praziquantel was higher in the snack schools, 93.9% (95% CI 91.7%-95.7%), compared to that in the non-snack schools, 78.7% (95% CI 75.4%-81.7%) (p = 0...

Ionic liquid ultrasound assisted dispersive liquid-liquid microextraction method for preconcentration of trace amounts of rhodium prior to flame atomic absorption spectrometry determination

Energy Technology Data Exchange (ETDEWEB)

Molaakbari, Elaheh [Chemistry Department, Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of); Young Research Society, Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of); Mostafavi, Ali, E-mail: mostafavi.ali@gmail.com [Chemistry Department, Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of); Afzali, Daryoush [Environment and Nanochemistry Department, Research Institute of Environmental Science, International Center for Science, High Technology and Environmental Science, Kerman (Iran, Islamic Republic of); Mineral Industries Research Center, Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of)

2011-01-30

In this article, we consider ionic liquid based ultrasound-assisted dispersive liquid-liquid microextraction of trace amounts of rhodium from aqueous samples and show that this is a fast and reliable sample pre-treatment for the determination of rhodium ions by flame atomic absorption spectrometry. The Rh(III) was transferred into its complex with 2-(5-bromo-2-pyridylazo)-5-diethylamino phenol as a chelating agent, and an ultrasonic bath with the ionic liquid, 1-octyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide at room temperature was used to extract the analyte. The centrifuged rhodium complex was then enriched in the form of ionic liquid droplets and prior to its analysis by flame atomic absorption spectrometry, 300 {mu}L ethanol was added to the ionic liquid-rich phase. Finally, the influence of various parameters on the recovery of Rh(III) was optimized. Under optimum conditions, the calibration graph was linear in the range of 4.0-500.0 ng mL{sup -1}, the detection limit was 0.37 ng mL{sup -1} (3S{sub b}/m, n = 7) and the relative standard deviation was {+-}1.63% (n = 7, C = 200 ng mL{sup -1}). The results show that ionic liquid based ultrasound assisted dispersive liquid-liquid microextraction, combined with flame atomic absorption spectrometry, is a rapid, simple, sensitive and efficient analytical method for the separation and determination of trace amounts of Rh(III) ions with minimum organic solvent consumption.

Fungal leaching of valuable metals from a power plant residual ash using Penicillium simplicissimum: Evaluation of thermal pretreatment and different bioleaching methods.

Science.gov (United States)

Rasoulnia, P; Mousavi, S M; Rastegar, S O; Azargoshasb, H

2016-06-01

Each year a tremendous volume of V-Ni rich ashes is produced by fuel oil consuming power plants throughout the world. Recovery of precious metals existing in these ashes is very important from both economic and environmental aspects. The present research was aimed at investigating bioleaching potential of Penicillium simplicissimum for the recovery of metals from power plant residual ash (PPR ash) using different bioleaching methods such as one-step, two-step, and spent-medium bioleaching at 1% (w/v) pulp density. Furthermore, the effects of thermal pretreatment on leaching of V, Ni, and Fe, as major elements present in PPR ash, were studied. Thermal pretreatment at various temperatures removed the carbonaceous and volatile fraction of the ash and affected the fungal growth and metal leachability. The highest extraction yields of V and Ni were achieved for the original PPR ash, using spent-medium bioleaching in which nearly 100% of V and 40% of Ni were extracted. The maximum extraction yield of Fe (48.3%) was obtained for the pretreated PPR ash at 400°C by spent-medium bioleaching. In addition, the fungal growth in pure culture was investigated through measurement of produced organic acids via high performance liquid chromatography (HPLC). Chemical leaching experiments were performed, using commercial organic acids at the same concentrations as those produced under optimum condition of fungal growth (5237ppm citric, 3666ppm gluconic, 1287ppm oxalic and 188ppm malic acid). It was found that in comparison to chemical leaching, bioleaching improved V and Ni recovery up to 19% and 12%, respectively. Moreover, changes in physical and chemical properties as well as morphology of the samples utilizing appropriate analytical methods such as XRF, XRD, FTIR, and FE-SEM were comprehensively investigated. Copyright © 2016 Elsevier Ltd. All rights reserved.

Determination of Alternaria mycotoxins in wine and juice using ionic liquid modified countercurrent chromatography as a pretreatment method followed by high-performance liquid chromatography.

Science.gov (United States)

Fan, Chen; Cao, Xueli; Liu, Man; Wang, Wei

2016-03-04

Alternariol (AOH), alternariol monomethyl ether (AME), and tenuazonic acid (TeA) are some of the main Alternaria mycotoxins that can be found as contaminants in food materials. The objective of this study was to develop a pretreatment method with countercurrent chromatography (CCC) for enrichment and cleanup of trace Alternaria mycotoxins in food samples prior to high-performance liquid chromatography (HPLC) analysis. An Analytical CCC instrument with a column volume 22.5mL was used, and a two-phase solvent system composed of ethyl acetate and water modified with 6% [HOOMIM][Cl] in mass to volume ratio was selected. Under the optimized CCC operation conditions, trace amounts of AOH, AME, and TeA in large volume of liquid sample were efficiently extracted and enriched in the stationary phase, and then eluted out just by reversing the stationary phase as mobile phase in the opposite flowing direction tail-to-head. The enrichment and elution strategies are unique and can be fulfilled online with high enrichment factors (87-114) and high recoveries (81.14-110.94%). The method has been successively applied to the determination of Alternaria mycotoxins in real apple juice and wine samples with the limits of detection (LOD) in the range of 0.03-0.14μgL(-1). Totally 12 wine samples and 15 apple juice samples from the local market were analyzed. The detection rate of AOH and AME in both kinds of the samples were more than 50%, while TeA was found in relatively high level of 1.75-49.61μgL(-1) in some of the apple juice samples. The proposed method is simple, rapid, and sensitive and could also be used for the analysis and monitoring of Alternaria mycotoxin in other food samples. Copyright © 2016 Elsevier B.V. All rights reserved.

Microbial Lipid Production from Enzymatic Hydrolysate of Pecan Nutshell Pretreated by Combined Pretreatment.

Science.gov (United States)

Qin, Lizhen; Qian, Hanyu; He, Yucai

2017-12-01

Biodiesel is a fuel composed of monoalkyl esters of long-chain fatty acids derived from renewable biomass sources. In this study, biomass waste pecan nutshell (PS) was attempted to be converted into microbial oil. For effective utilization of PS, sequential pretreatment with ethylene glycol-H 2 SO 4 -water (78:2:20, wt:wt:wt) at 130 °C for 30 min and aqueous ammonia (25 wt%) at 50 °C for 24 h was used to enhance its enzymatic saccharification. Significant linear correlation was obtained about delignification-saccharification (R 2  = 0.9507). SEM and FTIR results indicated that combination pretreatment could effectively remove lignin and xylan in PS for promoting its enzymatic saccharification. After 72 h, the reducing sugars from the hydrolysis of 50 g/L pretreated PS by combination pretreatment could be obtained at 73.6% yield. Using the recovered PS hydrolysates containing 20 g/L glucose as carbon source, microbial lipids produced from the PS hydrolysates by Rhodococcus opacus ACCC41043. Four fatty acids including palmitic acid (C16:0; 23.1%), palmitoleic acid (C16:1; 22.4%), stearic acid (C18:0; 15.3%), and oleic acid (C18:1; 23.9%) were distributed in total fatty acids. In conclusion, this strategy has potential application in the future.

Effect of ultrasonic pre-treatment of thermomechanical pulp on hydrogen peroxide bleaching

Science.gov (United States)

Loranger, E.; Charles, A.; Daneault, C.

2012-12-01

Ultrasound pre-treatments of softwood TMP had been carried to evaluate its impact on the efficiency of hydrogen peroxide bleaching. The trials were performed after a factorial design of experiment using frequency, power and time as variables. The experiments were conducted in an ultrasonic bath and then bleached with hydrogen peroxide. Measurements such as brightness, L*A*B* color system coordinate, residual hydrogen peroxide and metal content were evaluated on bleached pulp. The results indicate that the effect of ultrasonic treatment on brightness was dependent on the ultrasound frequency used; the brightness increased slightly at 68 kHz and decreased at 40 and 170 kHz. These results were correlated to the ultrasound effect on the generation of transition metals (copper, iron and manganese) which are responsible for catalytic decomposition of hydrogen peroxide. The influence of metal interference was minimized by using a chelating agent such as diethylene triamine pentaacetic acid (DTPA). With the results obtained in this study we have identified a set of option conditions, e.g. 1000 W, 40 kHz, 1.5 % consistency and 0.2% addition of DTPA prior to the bleaching stage (after ultrasonic pre-treatment) who improve brightness by 2.5 %ISO.

Detoxification of Corncob Acid Hydrolysate with SAA Pretreatment and Xylitol Production by Immobilized Candida tropicalis

Directory of Open Access Journals (Sweden)

Li-Hong Deng

2014-01-01

Full Text Available Xylitol fermentation production from corncob acid hydrolysate has become an attractive and promising process. However, corncob acid hydrolysate cannot be directly used as fermentation substrate owing to various inhibitors. In this work, soaking in aqueous ammonia (SAA pretreatment was employed to reduce the inhibitors in acid hydrolysate. After detoxification, the corncob acid hydrolysate was fermented by immobilized Candida tropicalis cell to produce xylitol. Results revealed that SAA pretreatment showed high delignification and efficient removal of acetyl group compounds without effect on cellulose and xylan content. Acetic acid was completely removed, and the content of phenolic compounds was reduced by 80%. Furthermore, kinetic behaviors of xylitol production by immobilized C. tropicalis cell were elucidated from corncob acid hydrolysate detoxified with SAA pretreatment and two-step adsorption method, respectively. The immobilized C. tropicalis cell showed higher productivity efficiency using the corncob acid hydrolysate as fermentation substrate after detoxification with SAA pretreatment than by two-step adsorption method in the five successive batch fermentation rounds. After the fifth round fermentation, about 60 g xylitol/L fermentation substrate was obtained for SAA pretreatment detoxification, while about 30 g xylitol/L fermentation substrate was obtained for two-step adsorption detoxification.

Biomass Deconstruction and Pretreatment | Bioenergy | NREL

Science.gov (United States)

Deconstruction and Pretreatment Biomass Deconstruction and Pretreatment Our mission is to transform -cyclohexane hydrocarbons were produced by noble metal and acid zeoloite catalytic upgrading of biomass-derived by mechanical refining process. The left side shows biomass feedstock (represented by brown spheres

Retinoids: literature review and suggested algorithm for use prior to facial resurfacing procedures

Directory of Open Access Journals (Sweden)

Patrick J Buchanan

2016-01-01

Full Text Available Vitamin A-containing products have been used topically since the early 1940s to treat various skin conditions. To date, there are four generations of retinoids, a family of Vitamin A-containing compounds. Tretinoin, all-trans-retinoic acid, is a first-generation, naturally occurring, retinoid. It is available, commercially, as a gel or cream. The authors conducted a complete review of all studies, clinical- and basic science-based studies, within the literature involving tretinoin treatment recommendations for impending facial procedures. The literature currently lacks definitive recommendations for the use of tretinoin-containing products prior to undergoing facial procedures. Tretinoin pretreatment regimens vary greatly in terms of the strength of retinoid used, the length of the pre-procedure treatment, and the ideal time to stop treatment before the procedure. Based on the current literature and personal experience, the authors set forth a set of guidelines for the use of tretinoin prior to various facial procedures.

Tank Focus Area pretreatment activities

International Nuclear Information System (INIS)

McGinnis, C.P.; Welch, T.D.; Manke, K.L.

1997-01-01

Plans call for the high-level wastes to be retrieved from the tanks and immobilized in a stable waste form suitable for long-term isolation. Chemistry and chemical engineering operations are required to retrieve the wastes, to condition the wastes for subsequent steps, and to reduce the costs of the waste management enterprise. Pretreatment includes those processes between retrieval and immobilization, and includes preparation of suitable feed material for immobilization and separations to partition the waste into streams that yield lower life-cycle costs. Some of the technologies being developed by the Tank Focus Area (TFA) to process these wastes are described. These technologies fall roughly into three areas: (1) solid/liquid separation (SLS), (2) sludge pretreatment, and (3) supernate pretreatment

Predictive factors of ovarian response and clinical outcome after IVF/ICSI following a rFSH/GnRH antagonist protocol with or without oral contraceptive pre-treatment

DEFF Research Database (Denmark)

Andersen, A Nyboe; Witjes, H; Gordon, K

2011-01-01

Prediction of ovarian response prior to the first controlled ovarian stimulation (COS) cycle is useful in determining the optimal starting dose of recombinant FSH (rFSH). However, potentially predictive factors may be subject to inter-cycle variability and many patients are pre-treated with oral ...

Influence of ultrasound pretreatment on wood physiochemical structure.

Science.gov (United States)

He, Zhengbin; Wang, Zhenyu; Zhao, Zijian; Yi, Songlin; Mu, Jun; Wang, Xiaoxu

2017-01-01

As an initial step to increase the use of renewable biomass resources, this study was aimed at investigating the effects of ultrasound pretreatment on structural changes of wood. Samples were pretreated by ultrasound with the power of 300W and frequency of 28kHz in aqueous soda solution, aqueous acetic acid, or distilled water, then pretreated and control samples were characterized via X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). The results shown that ultrasound pretreatment is indeed effective in modifying the physiochemical structure of eucalyptus wood; the pretreatment decreased the quantity of alkali metals (e.g., potassium, calcium and magnesium) in the resulting material. Compared to the control group, the residual char content of samples pretreated in aqueous soda solution increased by 10.08%-20.12% and the reaction temperature decreased from 361°C to 341°C, however, in samples pretreated by ultrasound in acetic solution or distilled water, the residual char content decreased by 12.40%-21.45% and there were no significant differences in reactivity apart from a slightly higher maximum reaction rate. Ultrasound pretreatment increased the samples' crystallinity up to 35.5% and successfully removed cellulose, hemicellulose, and lignin from the samples; the pretreatment also increased the exposure of the sample to the treatment solutions, broke down sample pits, and generated collapses and microchannels on sample pits, and removed attachments in the samples. Copyright © 2016 Elsevier B.V. All rights reserved.

Comparative study of sulfite pretreatments for robust enzymatic saccharification of corn cob residue

Directory of Open Access Journals (Sweden)

Bu Lingxi

2012-12-01

Full Text Available Abstract Background Corn cob residue (CCR is a kind of waste lignocellulosic material with enormous potential for bioethanol production. The moderated sulphite processes were used to enhance the hydrophily of the material by sulfonation and hydrolysis. The composition, FT-IR spectra, and conductometric titrations of the pretreated materials were measured to characterize variations of the CCR in different sulfite pretreated environments. And the objective of this study is to compare the saccharification rate and yield of the samples caused by these variations. Results It was found that the lignin in the CCR (43.2% had reduced to 37.8%, 38.0%, 35.9%, and 35.5% after the sulfite pretreatment in neutral, acidic, alkaline, and ethanol environments, respectively. The sulfite pretreatments enhanced the glucose yield of the CCR. Moreover, the ethanol sulfite sample had the highest glucose yield (81.2%, based on the cellulose in the treated sample among the saccharification samples, which was over 10% higher than that of the raw material (70.6%. More sulfonic groups and weak acid groups were produced during the sulfite pretreatments. Meanwhile, the ethanol sulfite treated sample had the highest sulfonic group (0.103 mmol/g and weak acid groups (1.85 mmol/g in all sulfite treated samples. In FT-IR spectra, the variation of bands at 1168 and 1190 cm-1 confirmed lignin sulfonation during sulfite pretreatment. The disappearance of the band at 1458 cm-1 implied the methoxyl on lignin had been removed during the sulfite pretreatments. Conclusions It can be concluded that the lignin in the CCR can be degraded and sulfonated during the sulfite pretreatments. The pretreatments improve the hydrophility of the samples because of the increase in sulfonic group and weak acid groups, which enhances the glucose yield of the material. The ethanol sulfite pretreatment is the best method for lignin removal and with the highest glucose yield.

Intrafraction Bladder Motion in Radiation Therapy Estimated From Pretreatment and Posttreatment Volumetric Imaging

Energy Technology Data Exchange (ETDEWEB)

Foroudi, Farshad, E-mail: farshad.foroudi@petermac.org [Division of Radiation Oncology, Peter MacCallum Cancer Centre, Melbourne, Victoria (Australia); Pham, Daniel [Radiation Therapy Services, Peter MacCallum Cancer Centre, Melbourne, Victoria (Australia); Bressel, Mathias [Biostatistics and Clinical Trials, Peter MacCallum Cancer Centre, Melbourne, Victoria (Australia); Gill, Suki [Division of Radiation Oncology, Peter MacCallum Cancer Centre, Melbourne, Victoria (Australia); Kron, Tomas [Physical Sciences, Peter MacCallum Cancer Centre, Melbourne, Victoria (Australia)

2013-05-01

Purpose: The use of image guidance protocols using soft tissue anatomy identification before treatment can reduce interfractional variation. This makes intrafraction clinical target volume (CTV) to planning target volume (PTV) changes more important, including those resulting from intrafraction bladder filling and motion. The purpose of this study was to investigate the required intrafraction margins for soft tissue image guidance from pretreatment and posttreatment volumetric imaging. Methods and Materials: Fifty patients with muscle-invasive bladder cancer (T2-T4) underwent an adaptive radiation therapy protocol using daily pretreatment cone beam computed tomography (CBCT) with weekly posttreatment CBCT. A total of 235 pairs of pretreatment and posttreatment CBCT images were retrospectively contoured by a single radiation oncologist (CBCT-CTV). The maximum bladder displacement was measured according to the patient's bony pelvis movement during treatment, intrafraction bladder filling, and bladder centroid motion. Results: The mean time between pretreatment and posttreatment CBCT was 13 minutes, 52 seconds (range, 7 min 52 sec to 30 min 56 sec). Taking into account patient motion, bladder centroid motion, and bladder filling, the required margins to cover intrafraction changes from pretreatment to posttreatment in the superior, inferior, right, left, anterior, and posterior were 1.25 cm (range, 1.19-1.50 cm), 0.67 cm (range, 0.58-1.12 cm), 0.74 cm (range, 0.59-0.94 cm), 0.73 cm (range, 0.51-1.00 cm), 1.20 cm (range, 0.85-1.32 cm), and 0.86 cm (range, 0.73-0.99), respectively. Small bladders on pretreatment imaging had relatively the largest increase in pretreatment to posttreatment volume. Conclusion: Intrafraction motion of the bladder based on pretreatment and posttreatment bladder imaging can be significant particularly in the anterior and superior directions. Patient motion, bladder centroid motion, and bladder filling all contribute to changes between

Energy efficacy used to score organic refuse pretreatment processes for hydrogen anaerobic production.

Science.gov (United States)

Ruggeri, Bernardo; Luongo Malave, Andrea C; Bernardi, Milena; Fino, Debora

2013-11-01

The production of hydrogen through Anaerobic Digestion (AD) has been investigated to verify the efficacy of several pretreatment processes. Three types of waste with different carbon structures have been tested to obtain an extensive representation of the behavior of the materials present in Organic Waste (OW). The following types of waste were selected: Sweet Product Residue (SPR), i.e., confectionary residue removed from the market after the expiration date, Organic Waste Market (OWM) refuse from a local fruit and vegetable market, and Coffee Seed Skin (CSS) waste from a coffee production plant. Several pretreatment processes have been applied, including physical, chemical, thermal, and ultrasonic processes and a combination of these processes. Two methods have been used for the SPR to remove the packaging, manual (SPR) and mechanical (SPRex). A pilot plant that is able to extrude the refuse to 200atm was utilized. Two parameters have been used to score the different pretreatment processes: efficiency (ξ), which takes into account the amount of energy produced in the form of hydrogen compared with the available energy embedded in the refuse, and efficacy (η), which compares the efficiency obtained using the pretreated refuse with that obtained using the untreated refuse. The best result obtained for the SPR was the basic pretreatment, with η=6.4, whereas the thermal basic pretreatment gave the highest value, η=17.0 for SPRex. The best result for the OWM was obtained through a combination of basic/thermal pretreatments with η=9.9; lastly, the CSS residue with ultrasonic pretreatment produced the highest quantity of hydrogen, η=5.2. Copyright © 2013 Elsevier Ltd. All rights reserved.

Enhancement of the effect of X-irradiation against cultured human glioblastoma cells by pretreatment with ACNU

Energy Technology Data Exchange (ETDEWEB)

Mashiyama, Shoji; Katakura, Ryuichi; Takahashi, Kou; Kitahara, Masakazu; Suzuki, Jiro [Tohoku Univ., Sendai (Japan). Inst. of Brain Diseases; Sasaki, Takehito

1989-12-01

Human glioblastoma A-7 (GB A-7) cells can apparently recover from potentially lethal X-irradiation. The authors, using a colony-forming assay, studied the influence of pretreatment with 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3- (2-chloroethyl)-3-nitrosourea hydrochloride (ACNU) on the effectiveness of X-irradiation against GB A-7 cells grown in monolayers and as multicellular spheroids. Pre-exposure to ACNU inhibited the recovery of irradiated GB A-7 cells. In monolayer cells, the combination treatment was most effective when ACNU was applied 2 to 8 hours prior to irradiation, and the larger the X-ray dose, the more potent the effect. ACNU pretreatment was more effective against large spheroids (enhancement ratio 1.86) than against small ones (1.34). Large spheroids showed necrosis, whereas small ones did not. Isobolographic analysis disclosed that the effect of combining X-irradiation and ACNU is within an additive envelope at the surviving fraction of 10{sup -2}, while supra-additive at the surviving fraction of 10{sup -3}. These results suggest that the potency of X-irradiation is augmented by ACNU pretreatment through an interactive mechanism. Further, suppression of recovery from X-ray induced potentially lethal damage was influenced by the presence of necrosis. (author).

Enhancement of the effect of X-irradiation against cultured human glioblastoma cells by pretreatment with ACNU

International Nuclear Information System (INIS)

Mashiyama, Shoji; Katakura, Ryuichi; Takahashi, Kou; Kitahara, Masakazu; Suzuki, Jiro; Sasaki, Takehito.

1989-01-01

Human glioblastoma A-7 (GB A-7) cells can apparently recover from potentially lethal X-irradiation. The authors, using a colony-forming assay, studied the influence of pretreatment with 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3- (2-chloroethyl)-3-nitrosourea hydrochloride (ACNU) on the effectiveness of X-irradiation against GB A-7 cells grown in monolayers and as multicellular spheroids. Pre-exposure to ACNU inhibited the recovery of irradiated GB A-7 cells. In monolayer cells, the combination treatment was most effective when ACNU was applied 2 to 8 hours prior to irradiation, and the larger the X-ray dose, the more potent the effect. ACNU pretreatment was more effective against large spheroids (enhancement ratio 1.86) than against small ones (1.34). Large spheroids showed necrosis, whereas small ones did not. Isobolographic analysis disclosed that the effect of combining X-irradiation and ACNU is within an additive envelope at the surviving fraction of 10 -2 , while supra-additive at the surviving fraction of 10 -3 . These results suggest that the potency of X-irradiation is augmented by ACNU pretreatment through an interactive mechanism. Further, suppression of recovery from X-ray induced potentially lethal damage was influenced by the presence of necrosis. (author)

Effects of glutamine pretreatment on learning and memory in heat-exposed rats

Institute of Scientific and Technical Information of China (English)

Shenghao Zhao; Lei Wang; Qin Wang; Siyi Wang; Chundi Deng; Xianfei Xie; Youe Yan; Hui Wang

2008-01-01

BACKGROUND: Glutamine (Gln) pretreatment can protect neural cells from injuries due to heat, ischemia, hypoxia, endotoxemia, and inflammatory factors.OBJECTIVE: To observe the effects of Gln pretreatment on learning and memory, survival time, and rectal temperature in heat-exposed rats.DESIGN, TIME AND SETTING: The present randomized grouping, neurobehavioral experiment was performed at the Laboratory of Department of Pharmacology, Basic School of Medicine, Wuhan University between March and September 2007.MATERIALS: Twenty-four healthy, Wistar rats were included in this study. SPX-160B biochemistry incubator (Shanghai Experimental Equipment Co., Ltd., China), probe electronic thermometer (11000 type, Maikepai Science and Technology Co., Ltd., China), Y-type maze box used in conjunction with MG-2 maze stimulator (Zhangjiagang Biomedical Instrument Factory, China), L-Gin (Batch No. 061218, 5 g/bottle, prepared into 10% aqueous solution, Amresco Company, USA) were used.METHODS: Twenty-four rats were randomly and evenly divided into 3 groups: heat-exposed, Gln low-lose, and Gln high-dose. Following learning and memory testing with the Y-maze, rats in the heat-exposed group were subjected to heat injury (40.5-41.5℃) in a biochemistry incubator. Rectal temperature was measured every 5 minutes. Thirty-five minutes after heat exposure, rats were removed and placed in the Y-type maze to test learning and memory again. Subsequently, the rats were returned to the same environment of thermal stimulation until they died. Rat survival time was recorded. Subsequent to learning and memory testing, rats in the Gln low-dose and high-dose groups received an i.p. injection of Gln (0.4 g/kg and 0.8 g/kg, respectively), and were exposed to heat injury. The remaining experimental procedures remained the same as for the heat-exposed group.MAIN OUTCOME MEASURES: Rat learning and memory, rectal temperature, and survival time in heat exposure environment.RESULTS: (1) In the Y

Promoting anaerobic biogasification of corn stover through biological pretreatment by liquid fraction of digestate (LFD).

Science.gov (United States)

Hu, Yun; Pang, Yunzhi; Yuan, Hairong; Zou, Dexun; Liu, Yanping; Zhu, Baoning; Chufo, Wachemo Akiber; Jaffar, Muhammad; Li, Xiujin

2015-01-01

A new biological pretreatment method by using liquid fraction of digestate (LFD) was advanced for promoting anaerobic biogasification efficiency of corn stover. 17.6% TS content and ambient temperature was appropriate for pretreatment. The results showed that C/N ratio decreased to about 30, while total lignin, cellulose, and hemicellulose (LCH) contents were reduced by 8.1-19.4% after pretreatment. 3-days pretreatment was considered to be optimal, resulting in 70.4% more biogas production, 66.3% more biomethane yield and 41.7% shorter technical digestion time compared with the untreated stover. The reductions on VS, cellulose, and hemicellulose were increased by 22.1-35.9%, 22.3-35.4%, and 19.8-27.2% for LFD-treated stovers. The promoted anaerobic biogasification efficiency was mainly attributed to the improved biodegradability due to the pre-decomposition role of the bacteria in LFD. The method proved to be an efficient and low cost approach for producing bioenergy from corn stover, meanwhile, reducing LFD discharge and minimizing its potential pollution. Copyright © 2014 Elsevier Ltd. All rights reserved.

Alkali-explosion pretreatment of straw and bagasse for enzymic hydrolysis.

Science.gov (United States)

Puri, V P; Pearce, G R

1986-04-01

Sugarcane bagasse and wheat straw were subjected to alkali treatment at 200 degrees C for 5 min and at 3.45 MPa gas pressure (steam and nitrogen), followed by an explosive discharge through a defibrating nozzle, in an attempt to improve the rate and extent of digestibility. The treatment resulted in the solubilization of 40-45% of the components and in the production of a pulp that gave saccharification yields of 80 and 65% in 8 h for bagasse and wheat straw, respectively. By comparison, alkali steaming at 200 degrees C (1.72 MPa) for 5 min gave saccharification yields of only 58 and 52% in 48 h. The increase in temperature from 140 to 200 degrees C resulted in a gradual increase in in vitro organic matter digestibility (IVOMD) for both the substrates. Also, the extent of alkalinity during pretreatment appears to effect the reactivity of the final product towards enzymes. Pretreatment times ranging from 5 to 60 caused a progressive decline in the IVOMD of bagasse and wheat straw by the alkali explosion method and this was accompanied by a progressive decrease in pH values after explosion. In the alkali-steaming method, pretreatment time had no apparent effect with either substrate. An analysis of the alkali-exploded products showed that substantial amounts of hemicellulose and a small proportion of the lignin were solubilized. The percentage crystallinity of the cellulose did not alter in either substrate but there was a substantial reduction in the degree of polymerization. The superiority of the alkali-explosion pretreatment is attributed to the efficacy of fiber separation and disintegration; this increases the surface area and reduces the degree of polymerization.

Hydrolysis of alkaline pretreated banana peel

Science.gov (United States)

Fatmawati, A.; Gunawan, K. Y.; Hadiwijaya, F. A.

2017-11-01

Banana peel is one of food wastes that are rich in carbohydrate. This shows its potential as fermentation substrate including bio-ethanol. This paper presented banana peel alkaline pretreatment and enzymatic hydrolysis. The pretreatment was intended to prepare banana peel in order to increase hydrolysis performance. The alkaline pretreatment used 10, 20, and 30% w/v NaOH solution and was done at 60, 70 and 80°C for 1 hour. The hydrolysis reaction was conducted using two commercial cellulose enzymes. The reaction time was varied for 3, 5, and 7 days. The best condition for pretreatment process was one conducted using 30% NaOH solution and at 80°C. This condition resulted in cellulose content of 90.27% and acid insoluble lignin content of 2.88%. Seven-day hydrolysis time had exhibited the highest reducing sugar concentration, which was7.2869 g/L.

Pretreatment of wheat straw for fermentation to methane

International Nuclear Information System (INIS)

Hashimoto, A.G.

1986-01-01

The effects of pretreating wheat straw with gamma-ray irradiation, ammonium hydroxide, and sodium hydroxide on methane yield, fermentation rate constant, and loss of feedstock constituents were evaluated using laboratory-scale batch fermentors. Results showed that methane yield increased as pretreatment alkali concentration increased, with the highest yield being 37% over untreated straw for the pretreatment consisting of sodium hydroxide dosage of 34 g OH - /kg volatile solids, at 90 0 C for 1 h. Gamma-ray irradiation had no significant effect on methane yield. Alkaline pretreatment temperatures above 100 0 C caused a decrease in methane yield. After more than 100 days of fermentation, all of the hemicellulose and more than 80% of the cellulose were degraded. The loss in cellulose and hemicellulose accounted for 100% of the volatile solids lost. No consistent effect of pretreatments on batch fermentation rates was noted. Semicontinuous fermentations of straw-manure mixtures confirmed the relative effectiveness of sodium- and ammonium-hydroxide pretreatments

Estimating Functions with Prior Knowledge, (EFPK) for diffusions

DEFF Research Database (Denmark)

Nolsøe, Kim; Kessler, Mathieu; Madsen, Henrik

2003-01-01

In this paper a method is formulated in an estimating function setting for parameter estimation, which allows the use of prior information. The main idea is to use prior knowledge of the parameters, either specified as moments restrictions or as a distribution, and use it in the construction of a...... of an estimating function. It may be useful when the full Bayesian analysis is difficult to carry out for computational reasons. This is almost always the case for diffusions, which is the focus of this paper, though the method applies in other settings.......In this paper a method is formulated in an estimating function setting for parameter estimation, which allows the use of prior information. The main idea is to use prior knowledge of the parameters, either specified as moments restrictions or as a distribution, and use it in the construction...

Delayed brain ischemia tolerance induced by electroacupuncture pretreatment is mediated via MCP-induced protein 1

Science.gov (United States)

2013-01-01

Background Emerging studies have demonstrated that pretreatment with electroacupuncture (EA) induces significant tolerance to focal cerebral ischemia. The present study seeks to determine the involvement of monocyte chemotactic protein-induced protein 1 (MCPIP1), a recently identified novel modulator of inflammatory reactions, in the cerebral neuroprotection conferred by EA pretreatment in the animal model of focal cerebral ischemia and to elucidate the mechanisms of EA pretreatment-induced ischemic brain tolerance. Methods Twenty-four hours after the end of the last EA pretreatment, focal cerebral ischemia was induced by middle cerebral artery occlusion (MCAO) for 90 minutes in male C57BL/6 mice and MCPIP1 knockout mice. Transcription and expression of MCPIP1 gene was monitored by qRT-PCR, Western blot and immunohistochemistry. The neurobehavioral scores, infarction volumes, proinflammatory cytokines and leukocyte infiltration in brain and NF-κB signaling were evaluated after ischemia/reperfusion. Results MCPIP1 protein and mRNA levels significantly increased specifically in mouse brain undergoing EA pretreatment. EA pretreatment significantly attenuated the infarct volume, neurological deficits, upregulation of proinflammatory cytokines and leukocyte infiltration in the brain of wild-type mice after MCAO compared with that of the non-EA group. MCPIP1-deficient mice failed to evoke EA pretreatment-induced tolerance compared with that of the control MCPIP1 knockout group without EA treatment. Furthermore, the activation of NF-κB signaling was significantly reduced in EA-pretreated wild-type mice after MCAO compared to that of the non-EA control group and MCPIP1-deficient mice failed to confer the EA pretreatment-induced inhibition of NF-κB signaling after MCAO. Conclusions Our data demonstrated that MCPIP1 deficiency caused significant lack of EA pretreatment-induced cerebral protective effects after MCAO compared with the control group and that MCPIP1 is

Enhanced Soluble Protein and Biochemical Methane Potential of Apple Biowaste by Different Pretreatment

Science.gov (United States)

Tulun, Şevket; Bilgin, Melayib

2018-05-01

The purpose of this research is to evaluate the anaerobic digestion of apple pomace waste in terms of pretreatment. In this study, the main pretreatment strategies for apple pomace include: ultrasound (35 and 53 kHz), thermal and chemical (pH 5 and 10). For each pretreatment method four different temperatures are selected as 25, 40, 50, and 60 °C, and operation times are selected as 5th, 15th, 30th, and 45th minutes. The effects on pretreatment were investigated by measuring changes in the soluble protein concentrations of pretreated wastes and the enhanced anaerobic digestion was investigated by using the biochemical methane potential (BMP) assay. The soluble proteins of ultrasonic (35 kHz at 60 °C, 45th min), ultrasonic (53 kHz at 60 °C, 45th min), chemical (pH 5 at 60 °C, 5th min), chemical (pH 10 at 60 °C, 30th min) and thermal chemical (40 °C, 15th min) pretreatment apple pomace were 74.3, 75.6, 48.7, 85.5 and 58.6% higher, respectively. The results indicated that apple pomace treated with 53 kHz at 60 °C, 45th min had the highest biogas yield of 1519 mL CH4/g VSS.day after anaerobic digestion, which was on average 40.9% higher than raw pomace.

Enhanced Soluble Protein and Biochemical Methane Potential of Apple Biowaste by Different Pretreatment

Science.gov (United States)

Tulun, Şevket; Bilgin, Melayib

2018-01-01

The purpose of this research is to evaluate the anaerobic digestion of apple pomace waste in terms of pretreatment. In this study, the main pretreatment strategies for apple pomace include: ultrasound (35 and 53 kHz), thermal and chemical (pH 5 and 10). For each pretreatment method four different temperatures are selected as 25, 40, 50, and 60 °C, and operation times are selected as 5th, 15th, 30th, and 45th minutes. The effects on pretreatment were investigated by measuring changes in the soluble protein concentrations of pretreated wastes and the enhanced anaerobic digestion was investigated by using the biochemical methane potential (BMP) assay. The soluble proteins of ultrasonic (35 kHz at 60 °C, 45th min), ultrasonic (53 kHz at 60 °C, 45th min), chemical (pH 5 at 60 °C, 5th min), chemical (pH 10 at 60 °C, 30th min) and thermal chemical (40 °C, 15th min) pretreatment apple pomace were 74.3, 75.6, 48.7, 85.5 and 58.6% higher, respectively. The results indicated that apple pomace treated with 53 kHz at 60 °C, 45th min had the highest biogas yield of 1519 mL CH4/g VSS.day after anaerobic digestion, which was on average 40.9% higher than raw pomace.

Prior-based artifact correction (PBAC) in computed tomography

International Nuclear Information System (INIS)

Heußer, Thorsten; Brehm, Marcus; Ritschl, Ludwig; Sawall, Stefan; Kachelrieß, Marc

2014-01-01

Purpose: Image quality in computed tomography (CT) often suffers from artifacts which may reduce the diagnostic value of the image. In many cases, these artifacts result from missing or corrupt regions in the projection data, e.g., in the case of metal, truncation, and limited angle artifacts. The authors propose a generalized correction method for different kinds of artifacts resulting from missing or corrupt data by making use of available prior knowledge to perform data completion. Methods: The proposed prior-based artifact correction (PBAC) method requires prior knowledge in form of a planning CT of the same patient or in form of a CT scan of a different patient showing the same body region. In both cases, the prior image is registered to the patient image using a deformable transformation. The registered prior is forward projected and data completion of the patient projections is performed using smooth sinogram inpainting. The obtained projection data are used to reconstruct the corrected image. Results: The authors investigate metal and truncation artifacts in patient data sets acquired with a clinical CT and limited angle artifacts in an anthropomorphic head phantom data set acquired with a gantry-based flat detector CT device. In all cases, the corrected images obtained by PBAC are nearly artifact-free. Compared to conventional correction methods, PBAC achieves better artifact suppression while preserving the patient-specific anatomy at the same time. Further, the authors show that prominent anatomical details in the prior image seem to have only minor impact on the correction result. Conclusions: The results show that PBAC has the potential to effectively correct for metal, truncation, and limited angle artifacts if adequate prior data are available. Since the proposed method makes use of a generalized algorithm, PBAC may also be applicable to other artifacts resulting from missing or corrupt data

Impact of co-pretreatment of calcium hydroxide and steam explosion on anaerobic digestion efficiency with corn stover.

Science.gov (United States)

Ji, Jinli; Zhang, Jiyu; Yang, Liutianyi; He, Yanfeng; Zhang, Ruihong; Liu, Guangqing; Chen, Chang

2017-06-01

Anaerobic digestion (AD) is an effective way to utilize the abundant resource of corn stover (CS). In this light, Ca(OH) 2 pretreatment alone, steam explosion (SE) pretreatment alone, and co-pretreatment of Ca(OH) 2 and SE were applied to improve the digestion efficiency of CS. Results showed that AD of co-pretreated CS with 1.0% Ca(OH) 2 and SE at 1.5 MPa achieved the highest cumulative methane yield of [Formula: see text], which was 61.54% significantly higher (p < .01) than untreated CS. The biodegradability value of CS after co-pretreatment enhanced from 43.03% to 69.52%. Methane yield could be well fitted by the first-order model and the modified Gompertz model. In addition, composition and structural changes of CS after pretreatment were analyzed by a fiber analyzer, scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction. The validated results indicated that co-pretreatment of Ca(OH) 2 and SE was efficient to improve the digestion performance of CS and might be a suitable method for agricultural waste pretreatment in the future AD industry.

Influence of chemical pretreatment of hard metal substrates for diamond deposition

International Nuclear Information System (INIS)

Buck, V.; Kluwe, H.; Schmiler, B.; Deuerler, F.

2001-01-01

Diamond coated cutting tools are of increasing importance in the fields of high speed cutting, dry machining or machining of special materials such as metal-matrix-composites. A well known problem is the poor adhesion of diamond films on hard metals due to the Co- or Ni-binder that catalyzes the formation of graphite. Several methods - such as the application of intermediate layers or mechanical or chemical pretreatment of the hard metal substrate - have been developed to overcome this effect. Usually chemical pretreatment is used in order to reduce the concentration of binder phase on the surface that is to be coated. Surprisingly pretreatment with agents such as Murakami's solution result in improved adhesion and nucleation of diamond films while the concentration of the binder phase on the surface is enhanced. This 'contradiction' can be explained by proving that the surface is converted into a very thin oxide/hydroxide film. (author)

Acid Pretreatment of Sago Wastewater for Biohydrogen Production

Science.gov (United States)

Illi Mohamad Puad, Noor; Rahim, Nurainin Farhan Abd; Suhaida Azmi, Azlin

2018-03-01

Biohydrogen has been recognized to be one of the future renewable energy sources and has the potential in solving the greenhouse effects. In this study, Enterobacter aerogenes (E. aerogenes) was used as the biohydrogen producer via dark fermentation process using sago wastewater as the substrate. However, pretreatment of sago wastewater is required since it consists of complex sugars that cannot be utilized directly by the bacteria. This study aimed to use acid pretreatment method to produce high amount of glucose from sago wastewater. Three different types of acid: sulfuric acid (H2SO4); hydrochloric acid (HCl) and nitric acid (HNO3) were screened for the best acid in producing a maximum amount of glucose. H2SO4 gave the highest amount of glucose which was 9.406 g/L. Design of experiment was done using Face-centred Central Composite Design (FCCCD) tool under Response Surface Methodology (RSM) in Design Expert 9 software. The maximum glucose (9.138 g/L) was recorded using 1 M H2SO4 at 100 °C for 60 min. A batch dark fermentation using E. aerogenes was carried out and it was found that pretreated sago wastewater gave a higher hydrogen concentration (1700 ppm) compared to the raw wastewater (410 ppm).

Impacts of microwave pretreatments on the semi-continuous anaerobic digestion of dairy waste activated sludge

International Nuclear Information System (INIS)

Uma Rani, R.; Adish Kumar, S.; Kaliappan, S.; Yeom, IckTae; Rajesh Banu, J.

2013-01-01

Highlights: ► Microwave pretreatment of dairy WAS was studied. ► MW pretreatment at 70% intensity for 12 min, COD solubilization was 18.6%. ► Biogas production and SS reduction was 35% and 14% higher than control. ► In digester at 15 days SRT with medium OLR, SS and VS reduction was 67% and 64%. ► Biogas and methane production was 57% and 49% higher than control, in digesters. - Abstract: Microwave (MW) irradiation is one of the new and possible methods used for pretreating the sludge. Following its use in different fields, this MW irradiation method has proved to be more appropriate in the field of environmental research. In this paper, we focused on the effects of MW irradiation at different intensities on solubilization, biodegradation and anaerobic digestion of sludge from the dairy sludge. The changes in the soluble fractions of the organic matter, the biogas yield, the methane content in the biogas were used as control parameters for evaluating the efficiency of the MW pretreatment. Additionally, the energetic efficiency was also examined. In terms of an energetic aspect, the most economical pretreatment of sludge was at 70% intensity for 12 min irradiation time. At this, COD solubilization, SS reduction and biogas production were found to be 18.6%, 14% and 35% higher than the control, respectively. Not only the increase in biogas production was investigated, excluding protein and carbohydrate hydrolysis was also performed successfully by this microwave pretreatment even at low irradiation energy input. Also, experiments were carried out in semi continuous anaerobic digesters, with 3.5 L working volume. Combining microwave pretreatment with anaerobic digestion led to 67%, 64% and 57% of SS reduction, VS reduction and biogas production higher than the control, respectively

Solubility of Plutonium (IV) Oxalate During Americium/Curium Pretreatment

International Nuclear Information System (INIS)

Rudisill, T.S.

1999-01-01

Approximately 15,000 L of solution containing isotopes of americium and curium (Am/Cm) will undergo stabilization by vitrification at the Savannah River Site (SRS). Prior to vitrification, an in-tank pretreatment will be used to remove metal impurities from the solution using an oxalate precipitation process. Material balance calculations for this process, based on solubility data in pure nitric acid, predict approximately 80 percent of the plutonium in the solution will be lost to waste. Due to the uncertainty associated with the plutonium losses during processing, solubility experiments were performed to measure the recovery of plutonium during pretreatment and a subsequent precipitation process to prepare a slurry feed for a batch melter. A good estimate of the plutonium content of the glass is required for planning the shipment of the vitrified Am/Cm product to Oak Ridge National Laboratory (ORNL).The plutonium solubility in the oxalate precipitation supernate during pretreatment was 10 mg/mL at 35 degrees C. In two subsequent washes with a 0.25M oxalic acid/0.5M nitric acid solution, the solubility dropped to less than 5 mg/mL. During the precipitation and washing steps, lanthanide fission products in the solution were mostly insoluble. Uranium, and alkali, alkaline earth, and transition metal impurities were soluble as expected. An elemental material balance for plutonium showed that greater than 94 percent of the plutonium was recovered in the dissolved precipitate. The recovery of the lanthanide elements was generally 94 percent or higher except for the more soluble lanthanum. The recovery of soluble metal impurities from the precipitate slurry ranged from 15 to 22 percent. Theoretically, 16 percent of the soluble oxalates should have been present in the dissolved slurry based on the dilution effects and volumes of supernate and wash solutions removed. A trace level material balance showed greater than 97 percent recovery of americium-241 (from the beta dec

Biologically Pre-Treated Habitation Waste Water as a Sustainable Green Urine Pre-Treat Solution

Science.gov (United States)

Jackson, W. Andrew; Thompson, Bret; Sevanthi, Ritesh; Morse, Audra; Meyer, Caitlin; Callahan, Michael

2017-01-01

The ability to recover water from urine and flush water is a critical process to allow long term sustainable human habitation in space or bases on the moon or mars. Organic N present as urea or similar compounds can hydrolyze producing free ammonia. This reaction results in an increase in the pH converting ammonium to ammonia which is volatile and not removed by distillation. The increase in pH will also cause precipitation reactions to occur. In order to prevent this, urine on ISS is combined with a pretreat solution. While use of a pretreatment solution has been successful, there are numerous draw backs including: storage and use of highly hazardous solutions, limitations on water recovery (less than 85%), and production of brine with pore dewatering characteristics. We evaluated the use of biologically treated habitation wastewaters (ISS and early planetary base) to replace the current pretreat solution. We evaluated both amended and un-amended bioreactor effluent. For the amended effluent, we evaluated "green" pretreat chemicals including citric acid and citric acid amended with benzoic acid. We used a mock urine/air separator modeled after the urine collection assembly on ISS. The urine/air separator was challenged continually for >6 months. Depending on the test point, the separator was challenged daily with donated urine and flushed with amended or un-amended reactor effluent. We monitored the pH of the urine, flush solution and residual pH in the urine/air separator after each urine event. We also evaluated solids production and biological growth. Our results support the use of both un-amended and amended bioreactor effluent to maintain the operability of the urine /air separator. The ability to use bioreactor effluent could decrease consumable cost, reduce hazards associated with current pre-treat chemicals, allow other membrane based desalination processes to be utilized, and improve brine characteristics.

Sets of priors reflecting prior-data conflict and agreement

NARCIS (Netherlands)

Walter, G.M.; Coolen, F.P.A.; Carvalho, J.P.; Lesot, M.-J.; Kaymak, U.; Vieira, S.; Bouchon-Meunier, B.; Yager, R.R.

2016-01-01

Bayesian inference enables combination of observations with prior knowledge in the reasoning process. The choice of a particular prior distribution to represent the available prior knowledge is, however, often debatable, especially when prior knowledge is limited or data are scarce, as then

Factors affecting seawater-based pretreatment of lignocellulosic date palm residues

DEFF Research Database (Denmark)

Fang, Chuanji; Thomsen, Mette Hedegaard; Frankaer, Christian Grundahl

2017-01-01

Seawater-based pretreatment of lignocellulosic biomass is an innovative process at research stage. With respect to process optimization, factors affecting seawater-based pretreatment of lignocellulosic date palm residues were studied for the first time in this paper. Pretreatment temperature (180...... °C–210 °C), salinity of seawater (0 ppt–50 ppt), and catalysts (H2SO4, Na2CO3, and NaOH) were investigated. The results showed that pretreatment temperature exerted the largest influence on seawater-based pretreatment in terms of the enzymatic digestibility and fermentability of pretreated solids...

Pretreatment Predictors of Adverse Radiation Effects After Radiosurgery for Arteriovenous Malformation

International Nuclear Information System (INIS)

Hayhurst, Caroline; Monsalves, Eric; Prooijen, Monique van; Cusimano, Michael; Tsao, May; Menard, Cynthia; Kulkarni, Abhaya V.; Schwartz, Michael; Zadeh, Gelareh

2012-01-01

Purpose: To identify vascular and dosimetric predictors of symptomatic T2 signal change and adverse radiation effects after radiosurgery for arteriovenous malformation, in order to define and validate preexisting risk models. Methods and Materials: A total of 125 patients with arteriovenous malformations (AVM) were treated at our institution between 2005 and 2009. Eighty-five patients have at least 12 months of clinical and radiological follow-up. Any new-onset headaches, new or worsening seizures, or neurological deficit were considered adverse events. Follow-up magnetic resonance images were assessed for new onset T2 signal change and the volume calculated. Pretreatment characteristics and dosimetric variables were analyzed to identify predictors of adverse radiation effects. Results: There were 19 children and 66 adults in the study cohort, with a mean age of 34 (range 6–74). Twenty-three (27%) patients suffered adverse radiation effects (ARE), 9 patients with permanent neurological deficit (10.6%). Of these, 5 developed fixed visual field deficits. Target volume and 12 Gy volume were the most significant predictors of adverse radiation effects on univariate analysis (p 3 , above which the rate of ARE increased dramatically. Multivariate analysis target volume and the absence of prior hemorrhage are the only significant predictors of ARE. The volume of T2 signal change correlates to ARE, but only target volume is predictive of a higher volume of T2 signal change. Conclusions: Target volume and the absence of prior hemorrhage is the most accurate predictor of adverse radiation effects and complications after radiosurgery for AVMs. A high percentage of permanent visual field defects in this series suggest the optic radiation is a critical radiosensitive structure.

Comparative Effects of Biomass Pre-Treatments for Direct and Indirect Transesterification to Enhance Microalgal Lipid Recovery

International Nuclear Information System (INIS)

Ghasemi Naghdi, Forough; Thomas-Hall, Skye R.; Durairatnam, Reuben; Pratt, Steven; Schenk, Peer M.

2014-01-01

Microalgal lipid recovery for biodiesel production is currently considered suboptimal, but pre-treatment of algal biomass, the use of solvent mixtures and the positioning of transesterification can lead to increased yields. Here, the effect of various reportedly successful pre-treatments and solvent mixtures were directly compared to each other and combined with direct and indirect transesterification methods using the oleaginous microalga Tetraselmis sp. M8. Microwave and thermal pre-treatments were applied and the total lipid and fatty acid methyl ester (FAME) recoveries were investigated. The application of pre-treatments increased FAME recovery through indirect transesterification when a Soxhlet system was used but they had no significant effect for direct transesterification. Gravimetric analyses of total lipids revealed that lipid recovery was highest when utilizing the chloroform-based Bligh and Dyer extraction method; however, FAME yield was the highest when applying a Soxhlet system utilizing a solvent mixture of hexane–ethanol (3:1). Total lipid recovery did not necessarily correlate with the recovery of FAMEs. The highest FAME recovery was achieved from thermal or microwave pre-treated biomass followed by indirect transesterification through Soxhlet extraction. FAME recovery could be more than doubled (increase of up to 171%) under these conditions. We conclude that a simple thermal pre-treatment (80°C for 10 min) in combination with solvent mixture extraction through indirect transesterification may present a cost-effective and scalable option for large-scale lipid extraction from microalgae.

Comparative effects of biomass pre-treatments for direct and indirect transesterification to enhance microalgal lipid recovery

Directory of Open Access Journals (Sweden)

Forough eGhasemi Naghdi

2014-12-01

Full Text Available Microalgal lipid recovery for biodiesel production is currently considered suboptimal, but pre-treatment of algal biomass, the use of solvent mixtures and the positioning of transesterification can lead to increased yields. Here, the effect of various reportedly successful pre-treatments and solvent mixtures were directly compared to each other and combined with direct and indirect transesterification methods using the oleaginous microalga Tetraselmis sp. M8. Microwave and thermal pre-treatments were applied and the total lipid and fatty acid methyl ester (FAME recoveries were investigated. The application of pre-treatments increased FAME recovery through indirect transesterification when a Soxhlet system was used but they had no significant effect for direct transesterification. Gravimetric analyses of total lipids revealed that lipid recovery was highest when utilizing the chloroform-based Bligh and Dyer extraction method; however FAME yield was the highest when applying a Soxhlet system utilizing a solvent mixture of hexane-ethanol (3:1. Total lipid recovery did not necessarily correlate with the recovery of FAMEs. The highest FAME recovery was achieved from thermal or microwave pre-treated biomass followed by indirect transesterification through Soxhlet extraction. FAME recovery could be more than doubled (increase of up to 171% under these conditions. We conclude that a simple thermal pre-treatment (80°C for 10 min in combination with solvent mixture extraction through indirect transesterification may present a cost-effective and scalable option for large-scale lipid extraction from microalgae.

Comparative Effects of Biomass Pre-Treatments for Direct and Indirect Transesterification to Enhance Microalgal Lipid Recovery

Energy Technology Data Exchange (ETDEWEB)

Ghasemi Naghdi, Forough; Thomas-Hall, Skye R.; Durairatnam, Reuben [Algae Biotechnology Laboratory, School of Agriculture and Food Sciences, The University of Queensland, Brisbane, QLD (Australia); Pratt, Steven [School of Chemical Engineering, The University of Queensland, Brisbane, QLD (Australia); Schenk, Peer M., E-mail: p.schenk@uq.edu.au [Algae Biotechnology Laboratory, School of Agriculture and Food Sciences, The University of Queensland, Brisbane, QLD (Australia)

2014-12-04

Microalgal lipid recovery for biodiesel production is currently considered suboptimal, but pre-treatment of algal biomass, the use of solvent mixtures and the positioning of transesterification can lead to increased yields. Here, the effect of various reportedly successful pre-treatments and solvent mixtures were directly compared to each other and combined with direct and indirect transesterification methods using the oleaginous microalga Tetraselmis sp. M8. Microwave and thermal pre-treatments were applied and the total lipid and fatty acid methyl ester (FAME) recoveries were investigated. The application of pre-treatments increased FAME recovery through indirect transesterification when a Soxhlet system was used but they had no significant effect for direct transesterification. Gravimetric analyses of total lipids revealed that lipid recovery was highest when utilizing the chloroform-based Bligh and Dyer extraction method; however, FAME yield was the highest when applying a Soxhlet system utilizing a solvent mixture of hexane–ethanol (3:1). Total lipid recovery did not necessarily correlate with the recovery of FAMEs. The highest FAME recovery was achieved from thermal or microwave pre-treated biomass followed by indirect transesterification through Soxhlet extraction. FAME recovery could be more than doubled (increase of up to 171%) under these conditions. We conclude that a simple thermal pre-treatment (80°C for 10 min) in combination with solvent mixture extraction through indirect transesterification may present a cost-effective and scalable option for large-scale lipid extraction from microalgae.

Evaluation of Parallel Level Sets and Bowsher's Method as Segmentation-Free Anatomical Priors for Time-of-Flight PET Reconstruction.

Science.gov (United States)

Schramm, Georg; Holler, Martin; Rezaei, Ahmadreza; Vunckx, Kathleen; Knoll, Florian; Bredies, Kristian; Boada, Fernando; Nuyts, Johan

2018-02-01

In this article, we evaluate Parallel Level Sets (PLS) and Bowsher's method as segmentation-free anatomical priors for regularized brain positron emission tomography (PET) reconstruction. We derive the proximity operators for two PLS priors and use the EM-TV algorithm in combination with the first order primal-dual algorithm by Chambolle and Pock to solve the non-smooth optimization problem for PET reconstruction with PLS regularization. In addition, we compare the performance of two PLS versions against the symmetric and asymmetric Bowsher priors with quadratic and relative difference penalty function. For this aim, we first evaluate reconstructions of 30 noise realizations of simulated PET data derived from a real hybrid positron emission tomography/magnetic resonance imaging (PET/MR) acquisition in terms of regional bias and noise. Second, we evaluate reconstructions of a real brain PET/MR data set acquired on a GE Signa time-of-flight PET/MR in a similar way. The reconstructions of simulated and real 3D PET/MR data show that all priors were superior to post-smoothed maximum likelihood expectation maximization with ordered subsets (OSEM) in terms of bias-noise characteristics in different regions of interest where the PET uptake follows anatomical boundaries. Our implementation of the asymmetric Bowsher prior showed slightly superior performance compared with the two versions of PLS and the symmetric Bowsher prior. At very high regularization weights, all investigated anatomical priors suffer from the transfer of non-shared gradients.

Microwave pretreatment of switchgrass for bioethanol production

Science.gov (United States)

Keshwani, Deepak Radhakrishin

Lignocellulosic materials are promising alternative feedstocks for bioethanol production. These materials include agricultural residues, cellulosic waste such as newsprint and office paper, logging residues, and herbaceous and woody crops. However, the recalcitrant nature of lignocellulosic biomass necessitates a pretreatment step to improve the yield of fermentable sugars. The overall goal of this dissertation is to expand the current state of knowledge on microwave-based pretreatment of lignocellulosic biomass. Existing research on bioenergy and value-added applications of switchgrass is reviewed in Chapter 2. Switchgrass is an herbaceous energy crop native to North America and has high biomass productivity, potentially low requirements for agricultural inputs and positive environmental impacts. Based on results from test plots, yields in excess of 20 Mg/ha have been reported. Environmental benefits associated with switchgrass include the potential for carbon sequestration, nutrient recovery from run-off, soil remediation and provision of habitats for grassland birds. Published research on pretreatment of switchgrass reported glucose yields ranging from 70-90% and xylose yields ranging from 70-100% after hydrolysis and ethanol yields ranging from 72-92% after fermentation. Other potential value-added uses of switchgrass include gasification, bio-oil production, newsprint production and fiber reinforcement in thermoplastic composites. Research on microwave-based pretreatment of switchgrass and coastal bermudagrass is presented in Chapter 3. Pretreatments were carried out by immersing the biomass in dilute chemical reagents and exposing the slurry to microwave radiation at 250 watts for residence times ranging from 5 to 20 minutes. Preliminary experiments identified alkalis as suitable chemical reagents for microwave-based pretreatment. An evaluation of different alkalis identified sodium hydroxide as the most effective alkali reagent. Under optimum pretreatment

Formulating informative, data-based priors for failure probability estimation in reliability analysis

International Nuclear Information System (INIS)

Guikema, Seth D.

2007-01-01

Priors play an important role in the use of Bayesian methods in risk analysis, and using all available information to formulate an informative prior can lead to more accurate posterior inferences. This paper examines the practical implications of using five different methods for formulating an informative prior for a failure probability based on past data. These methods are the method of moments, maximum likelihood (ML) estimation, maximum entropy estimation, starting from a non-informative 'pre-prior', and fitting a prior based on confidence/credible interval matching. The priors resulting from the use of these different methods are compared qualitatively, and the posteriors are compared quantitatively based on a number of different scenarios of observed data used to update the priors. The results show that the amount of information assumed in the prior makes a critical difference in the accuracy of the posterior inferences. For situations in which the data used to formulate the informative prior is an accurate reflection of the data that is later observed, the ML approach yields the minimum variance posterior. However, the maximum entropy approach is more robust to differences between the data used to formulate the prior and the observed data because it maximizes the uncertainty in the prior subject to the constraints imposed by the past data

The pretreatment cost of a pyroprocess facility in Korea

International Nuclear Information System (INIS)

Kim, S. K.; Youn, S. R.; Lee, S. H.; Lee, H. J.; Ko, W. I.

2015-01-01

Shale gas still has many disadvantages such as significant technological difficulties and high costs even when the fracking technology is used to extract shale gas since shale gas is dispersed widely. Moreover, it is estimated that the shale gas can be used for about 60 years, which is comparable to the period estimated for oil deposits. Another concern is that the climate may change due to the discharge of harmful gas produced during the gas extraction process. PRIDE facility producing 10 ton/year uranium ingot was set as the cost object for the cost estimation, and it was possible to increase cost calculation's accuracy level since labor cost and expenses incurred in this facility were the costs incurred in actuality. In the end, First-In, First Out process costing method was used to calculate the pretreatment cost of pyroprocess. According to the cost calculation results, the pretreatment cost was estimated as $195/kgHM and the cost share of the pretreatment of pyroprocess was calculated as 20%. Accordingly, electrochemical reduction process is the process requires most cost, followed by the cost of electro-winning process

The pretreatment cost of a pyroprocess facility in Korea

Energy Technology Data Exchange (ETDEWEB)

Kim, S. K.; Youn, S. R.; Lee, S. H.; Lee, H. J.; Ko, W. I. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-05-15

Shale gas still has many disadvantages such as significant technological difficulties and high costs even when the fracking technology is used to extract shale gas since shale gas is dispersed widely. Moreover, it is estimated that the shale gas can be used for about 60 years, which is comparable to the period estimated for oil deposits. Another concern is that the climate may change due to the discharge of harmful gas produced during the gas extraction process. PRIDE facility producing 10 ton/year uranium ingot was set as the cost object for the cost estimation, and it was possible to increase cost calculation's accuracy level since labor cost and expenses incurred in this facility were the costs incurred in actuality. In the end, First-In, First Out process costing method was used to calculate the pretreatment cost of pyroprocess. According to the cost calculation results, the pretreatment cost was estimated as $195/kgHM and the cost share of the pretreatment of pyroprocess was calculated as 20%. Accordingly, electrochemical reduction process is the process requires most cost, followed by the cost of electro-winning process.

Does pretreatment hemoglobin level affect outcome in patients with T1 glottic cancer?

International Nuclear Information System (INIS)

Canaday, Daniel J.; Regine, William F.; Mohiuddin, Mohammed; Zollinger, William; Machtay, Mitchell; Lee, Jason; Schultz, Delray; Rosenthal, David I.; Rudoltz, Marc S.

1997-01-01

Purpose/Objective: Recent reports have suggested that pretreatment hemoglobin (Hgb) is significantly associated with local control (LC) and overall survival (OS) in patients with T1 and T2 squamous cell carcinoma of the glottic larynx. This study evaluates the association of pretreatment Hgb level and other factors with outcome in patients limited to T1 squamous cell carcinoma of the glottic larynx treated with external beam radiation. Methods: One hundred fifty-eight patients with T1 squamous cell carcinoma of the glottic larynx were analyzed. Median follow-up was 5 years (range 2-22). Median pretreatment Hgb was 14.4 gm/dl (range 8.2-17.2). The following parameters were analyzed for their impact on LC, OS, and disease specific survival (DSS): age, gender, pretreatment Hgb, tumor grade, anterior commissure involvement, field size, total dose, dose per fraction, and overall treatment time. Results: Five year actuarial LC was 84%. Pretreatment Hgb was not a significant predictor for LC when assessed as a continuous variable (p=0.38). LC was 82% for patients with Hgb >13 vs 92% for Hgb ≤ 13 (p=0.13). No other factor was significant for LC. Five year actuarial OS was 74%. On univariate analysis, pretreatment Hgb ≤ 13 gm/dl was a significant factor for poorer OS (78% vs 68%, p=0.004), as were total dose 61 years (p=0.017). On multivariate analysis, only age >61 (p=0.014) and Hgb ≤ 13 (p=0.001) retained significance for OS. Five year actuarial DSS was 92%. Pretreatment Hgb was not a prognostic factor for DSS, nor were any other analyzed factors. Conclusion: Pretreatment Hgb is not a significant prognostic factor for LC in patients with T1 squamous cell carcinoma of the glottic larynx, but it does predict for a poorer OS without affecting DSS. This suggests that patients with lower pretreatment Hgb may have confounding medical problems which detract from their overall survival

Lignocellulose pretreatment technologies affect the level of enzymatic cellulose oxidation by LPMO

DEFF Research Database (Denmark)

Rodríguez-Zúñiga, Ursula Fabiola; Cannella, David; de Campos Giordano, Roberto

2015-01-01

of the cellulose oxidizing enzyme lytic polysaccharide monooxygenase (LPMO). The highest activity of LPMO was observed for the hydrothermally pretreated biomasses, which also contained the highest level of lignin. All hydrolysis were done at high dry matter levels, using a commercial enzyme preparation containing......Sugarcane bagasse, corn stover, and wheat straw are among the most available resources for production of cellulosic ethanol. For these biomasses we study the influence of pre-treatment methods on the chemical composition, as well as on the subsequent reactions of enzymatic hydrolysis and oxidation...

Pretreating lignocellulosic biomass by the concentrated phosphoric acid plus hydrogen peroxide (PHP) for enzymatic hydrolysis: evaluating the pretreatment flexibility on feedstocks and particle sizes.

Science.gov (United States)

Wang, Qing; Wang, Zhanghong; Shen, Fei; Hu, Jinguang; Sun, Fubao; Lin, Lili; Yang, Gang; Zhang, Yanzong; Deng, Shihuai

2014-08-01

In order to seek a high-efficient pretreatment path for converting lignocellulosic feedstocks to fermentable sugars by enzymatic hydrolysis, the concentrated H₃PO₄ plus H₂O₂ (PHP) was attempted to pretreat different lignocellulosic biomass for evaluating the pretreatment flexibility on feedstocks. Meanwhile, the responses of pretreatment to particle sizes were also evaluated. When the PHP-pretreatment was employed (final H₂O₂ and H₃PO₄ concentration of 1.77% and 80.0%), 71-96% lignin and more than 95% hemicellulose in various feedstocks (agricultural residues, hardwood, softwood, bamboo, and their mixture, and garden wastes mixture) can be removed. Consequently, more than 90% glucose conversion was uniformly achieved indicating PHP greatly improved the pretreatment flexibility to different feedstocks. Moreover, when wheat straw and oak chips were PHP-pretreated with different sizes, the average glucose conversion reached 94.9% and 100% with lower coefficient of variation (7.9% and 0.0%), which implied PHP-pretreatment can significantly weaken the negative effects of feedstock sizes on subsequent conversion. Copyright © 2014 Elsevier Ltd. All rights reserved.

NON-POLLUTING METAL SURFACE FINISHING PRETREATMENT AND PRETREATMENT/CONVERSION COATING

Science.gov (United States)

Picklex, a proprietary formulation, is an alterantive to conventional metal surface pretreatments and is claimed not to produce waste or lower production or lower performance. A laboratory program was designed to evaluate Picklex in common, large scale, polluting surface finishin...

Dilute alkali pretreatment of softwood pine: A biorefinery approach.

Science.gov (United States)

Safari, Ali; Karimi, Keikhosro; Shafiei, Marzieh

2017-06-01

Dilute alkali pretreatment was performed on softwood pine to maximize ethanol and biogas production via a biorefinery approach. Alkali pretreatments were performed with 0-2% w/v NaOH at 100-180°C for 1-5h. The liquid fraction of the pretreated substrates was subjected to anaerobic digestion. The solid fraction of the pretreatment was used for separate enzymatic hydrolysis and fermentation. High ethanol yields of 76.9‒78.0% were achieved by pretreatment with 2% (w/v) NaOH at 180°C. The highest biogas yield of 244mL/g volatile solid (at 25°C, 1bar) was achieved by the pretreatment with 1% (w/v) NaOH at 180°C. The highest gasoline equivalent (sum of ethanol and methane) of 197L per ton of pinewood and the lowest ethanol manufacturing cost of 0.75€/L was obtained after pretreatment with 1% NaOH at 180°C for 5h. The manufacturing cost of ethanol from untreated wood was 4.12€/L. Copyright © 2017 Elsevier Ltd. All rights reserved.

Pretreatment with U(IV) solution for improving the decontamination of ruthenium

International Nuclear Information System (INIS)

Huang Haoxin; Qi Zhanshun; Zhu Guohui

1993-01-01

The ruthenium decontamination factor in Purex process falls quickly in successive TBP cycles. So, it is necessary to change the chemical states of RuNO complexes in order to improve DF Ru in the uranium purification cycle. Hydrazine nitrate is being used to transform RuNO complexes into in-extractable Ru(III)and Ru(IV). However, hydrazine nitrate may be inverted into hydrazoic acid which is dangerous and can bring an unstable factor. Pretreatment using U(IV) solution provides another method to improve the decontamination of ruthenium in Purex process. 0.02 mol/lU(IV) solution can transform RuNO complexes into inextricable species by heating in water bath. The D Ru can be decreased by a factor of 10-20. U(IV) pretreatment does not bring any harmful chemical in process. The acidity has a very large influence on the effect of pretreatment. The higher the acidity is, the worse the effect will be

Effect of different pretreatments on dried chilli (Capsicum annum L.) quality

Science.gov (United States)

Anoraga, S. B.; Sabarisman, I.; Ainuri, M.

2018-03-01

Chilli (Capsicum annum L.) has significant price fluctuation. When the chilli price is declined, it causes food waste from unsold chilli. Therefore, drying chilli is a solution for this condition. Futhermore, it can be processed for various product like chilli powder, chilli sauce, etc. The aim of this study was to investigate the effect of different pretreatments on dried chilli quality. Chilli was blenched with hot water and steam before drying. The purpose of this pretreatments is to inactivate enzyme that prevents color and vitamin C losses. The quality parameters were moisture content, colour, vitamin C content, and capsaicin. Changes were observed by gravimetri method for moisture content, chromameter in L* a * b * colour model, and iodine titration for vitamin C. After drying for 20 hours at 60°C, chilli with steam blanching pretreatment dried rapidly than other samples. Unpretreated chilli had higher vitamin C content and better color than blanched chilli.

Review: Waste-Pretreatment Technologies for Remediation of Legacy Defense Nuclear Wastes

Energy Technology Data Exchange (ETDEWEB)

Wilmarth, William R.; Lumetta, Gregg J.; Johnson, Michael E.; Poirier, Micheal R.; Thompson, Major C.; Suggs, Patricia C.; Machara, N.

2011-01-13

The U.S. Department of Energy (DOE) is responsible for retrieving, immobilizing, and disposing of radioactive waste that has been generated during the production of nuclear weapons in the United States. The vast bulk of this waste material is stored in underground tanks at the Savannah River Site in South Carolina and the Hanford Site in Washington State. The general strategy for treating the radioactive tank waste consists of first separating the waste into high-level and low-activity fractions. This initial partitioning of the waste is referred to as pretreatment. Following pretreatment, the high-level fraction will be immobilized in a glass form suitable for disposal in a geologic repository. The low-activity waste will be immobilized in a waste form suitable for disposal at the respective site. This paper provides a review of recent developments in the application of pretreatment technologies to the processing of the Hanford and Savannah River radioactive tank wastes. Included in the review are discussions of 1) solid/liquid separations methods, 2) cesium separation technologies, and 3) other separations critical to the success of the DOE tank waste remediation effort. Also included is a brief discussion of the different requirements and circumstances at the two DOE sites that have in some cases led to different choices in pretreatment technologies.

Cholesterol added prior to vitrification on the cryotolerance of immature and in vitro matured bovine oocytes.

Directory of Open Access Journals (Sweden)

Núria Arcarons

Full Text Available This study examines whether incorporating cholesterol-loaded methyl-β-cyclodextrin (CLC in the bovine oocyte plasma membrane improves oocyte tolerance to vitrification. In vitro matured oocytes were incubated with 2 mg/ml BODIPY-labeled CLC for different time intervals in FCS or PVA supplemented medium or exposed to different CLC concentrations to examine the subcellular localization of cholesterol by confocal microscopy live-cell imaging. Subsequently, the effects of optimized CLC concentrations and incubation times prior to vitrification on early embryo development were assessed. Then, we evaluated the effects of pretreatment with 2 mg/ml CLC for 30 min before the vitrification of immature (GV and in vitro matured (MII oocytes on developmental competence and gene expression. Our results indicate a high plasma membrane labeling intensity after 30 min of incubation with 2 mg/ml CLC for 30 min, regardless of the holding medium used. When oocytes were incubated with 1 mg/ml, 2 mg/ml and 3 mg/ml of CLC, intense labeling was observed at the plasma membrane after 40, 30 and 20 min, respectively. CLC pre-treatment before the vitrification of bovine oocytes did not affect subsequent cleavage and embryo development rates irrespective of CLC concentrations, incubation times or meiotic stage. However, pretreatment seems to improve the quality of embryos derived from vitrified oocytes, mainly when oocytes were vitrified at the GV stage.

Treatment of textile dyehouse effluent using ceramic membrane based process in combination with chemical pretreatment.

Science.gov (United States)

Bhattacharya, Priyankari; Ghosh, Sourja; Majumdar, Swachchha; Bandyopadhyay, Sibdas

2013-10-01

Treatment of highly concentrated dyebath effluent and comparatively dilute composite effluent having mixture of various reactive dyes collected from a cotton fabric dyeing unit was undertaken in the present study. Ceramic microfiltration membrane prepared from a cost effective composition of alumina and clay was used. Prior to microfiltration, a chemical pretreatment was carried out with aluminium sulphate in combination with a polymeric retention aid. An optimum dose of 100 mg/L of aluminium sulphate and 1 ml/L of a commercial flocculant Afilan RAMF was found effective for dye removal (> 98%) from the synthetic solutions of reactive dyes with initial concentration of 150 mg/L in both the single component and two component systems. In the microfiltration study, effect of operating pressure in the permeate flux was observed for both the pretreated and untreated effluents and permeate samples were analyzed for dye concentration, COD, turbidity, TSS, etc. during constant pressure filtration. About 98-99% removal of dyes was obtained in the combined process with COD reduction of 54-64%.

Silane pre-treatments on copper and aluminium

International Nuclear Information System (INIS)

Deflorian, F.; Rossi, S.; Fedrizzi, L.

2006-01-01

A large part of aluminium products are coated with an organic layer in order to improve the corrosion resistance. Copper surfaces are also sometimes protected with an organic coating to improve the durability or the aesthetic properties. Examples of industrial applications are household appliances and heat exchanger components. For these applications it is not rare to have the industrial need to treat at the same time components made of aluminium and copper. In order to extend the service life of the organic coated copper a specific surface pre-treatment is often required. Nevertheless, probably because of the limited market of this application, no specific pre-treatments for copper are industrially developed, with the exception of cleaning procedures, but simply extensions of existing pre-treatments optimised for other metals (aluminium, zinc) are used. The application of silane pre-treatments as adhesion promoters for organic coated metals is remarkably increasing in the last decade, because silanes offer very good performance together with high environmental compatibility. The idea is therefore to try to develop a specific silane based pre-treatment for copper. The starting point is the existing silane products for aluminium, optimising the composition and the application conditions (concentration, temperature, pH of the bath, etc.) in order to develop a high performance copper alloy pre-treatment increasing the protective properties and the adhesion of a successively applied organic coating. Moreover these pre-treatments could be used for aluminium alloys too and therefore could be suggested for multi-metals components. The deposits were analysed using FTIR spectroscopy and optical and electron microscopic observations. A careful electrochemical characterisation, mainly by electrochemical impedance spectroscopy measurements (EIS) was carried out to highlight the presence of silane and to evaluate the performance of the different deposits. In order to study an

Prospective regularization design in prior-image-based reconstruction

International Nuclear Information System (INIS)

Dang, Hao; Siewerdsen, Jeffrey H; Stayman, J Webster

2015-01-01

Prior-image-based reconstruction (PIBR) methods leveraging patient-specific anatomical information from previous imaging studies and/or sequences have demonstrated dramatic improvements in dose utilization and image quality for low-fidelity data. However, a proper balance of information from the prior images and information from the measurements is required (e.g. through careful tuning of regularization parameters). Inappropriate selection of reconstruction parameters can lead to detrimental effects including false structures and failure to improve image quality. Traditional methods based on heuristics are subject to error and sub-optimal solutions, while exhaustive searches require a large number of computationally intensive image reconstructions. In this work, we propose a novel method that prospectively estimates the optimal amount of prior image information for accurate admission of specific anatomical changes in PIBR without performing full image reconstructions. This method leverages an analytical approximation to the implicitly defined PIBR estimator, and introduces a predictive performance metric leveraging this analytical form and knowledge of a particular presumed anatomical change whose accurate reconstruction is sought. Additionally, since model-based PIBR approaches tend to be space-variant, a spatially varying prior image strength map is proposed to optimally admit changes everywhere in the image (eliminating the need to know change locations a priori). Studies were conducted in both an ellipse phantom and a realistic thorax phantom emulating a lung nodule surveillance scenario. The proposed method demonstrated accurate estimation of the optimal prior image strength while achieving a substantial computational speedup (about a factor of 20) compared to traditional exhaustive search. Moreover, the use of the proposed prior strength map in PIBR demonstrated accurate reconstruction of anatomical changes without foreknowledge of change locations in

Biodelignification of lignocellulose substrates: An intrinsic and sustainable pretreatment strategy for clean energy production.

Science.gov (United States)

Chandel, Anuj K; Gonçalves, Bruna C M; Strap, Janice L; da Silva, Silvio S

2015-01-01

Lignocellulosic biomass (LB) is a promising sugar feedstock for biofuels and other high-value chemical commodities. The recalcitrance of LB, however, impedes carbohydrate accessibility and its conversion into commercially significant products. Two important factors for the overall economization of biofuel production is LB pretreatment to liberate fermentable sugars followed by conversion into ethanol. Sustainable biofuel production must overcome issues such as minimizing water and energy usage, reducing chemical usage and process intensification. Amongst available pretreatment methods, microorganism-mediated pretreatments are the safest, green, and sustainable. Native biodelignifying agents such as Phanerochaete chrysosporium, Pycnoporous cinnabarinus, Ceriporiopsis subvermispora and Cyathus stercoreus can remove lignin, making the remaining substrates amenable for saccharification. The development of a robust, integrated bioprocessing (IBP) approach for economic ethanol production would incorporate all essential steps including pretreatment, cellulase production, enzyme hydrolysis and fermentation of the released sugars into ethanol. IBP represents an inexpensive, environmentally friendly, low energy and low capital approach for second-generation ethanol production. This paper reviews the advancements in microbial-assisted pretreatment for the delignification of lignocellulosic substrates, system metabolic engineering for biorefineries and highlights the possibilities of process integration for sustainable and economic ethanol production.

One-Bath Pretreatment for Enhanced Color Yield of Ink-Jet Prints Using Reactive Inks

Directory of Open Access Journals (Sweden)

Wei Ma

2017-11-01

Full Text Available In order to facilely increase the color yield of ink-jet prints using reactive inks, one-bath pretreatment of cotton fabrics with pretreatment formulation containing sodium alginate, glycidyltrimethylammonium chloride (GTA, sodium hydroxide, and urea is designed for realizing sizing and cationization at the same time. The pretreatment conditions, including the concentrations of GTA and alkali, baking temperature, and time are optimized based on the result of thecolor yield on cationic cotton for magenta ink. The mechanism for color yield enhancement on GTA-modified fabrics is discussed and the stability of GTA in the print paste is investigated. Scanning electron microscopey, tear strength, and thermogravimetric analysis of the modified and unmodified cotton are studied and compared. Using the optimal pretreatment conditions, color yield on the cationic cotton for magenta, cyan, yellow, and black reactive inks are increased by 128.7%, 142.5%, 71.0%, and 38.1%, respectively, compared with the corresponding color yield on the uncationized cotton. Much less wastewater is produced using this one-bath pretreatment method. Colorfastness of the reactive dyes on the modified and unmodified cotton is compared and boundary clarity between different colors is evaluated by ink-jet printing of colorful patterns.

Research of small quaternary AChE inhibitors as pretreatment of OP poisoning

International Nuclear Information System (INIS)

Musilek, K.; Komloova, M.; Holas, O.; Opletalova, V.; Pohanka, M.; Kuca, K.

2009-01-01

Small quaternary AChE inhibitors are used (e.g. pyridostigmine) or scoped (e.g. SAD-128) for pretreatment against organophosphate intoxication [1]. The pretreatment is based on competitive inhibition of AChE prior to organophosphate (OP) poisoning. Consequently, the OP can not influence the inhibited AChE and is degraded by other esterases. Although various competitive inhibitors are used globally, pyridostigmine still remains the most broaden. Its side effects including gastrointestinal effects (nausea, intestinal obstruction), increased bronchial secretion, cardiac arrhythmia or cholinergic crisis are well described. Moreover, some bisquaternary competitive inhibitors (e.g. SAD-128) were used to decrease lethal effects of OP poisoning in vivo. The further studies dealing with SAD-128 showed its increased ability to interact with brain muscarinic acetylcholine receptors as allosteric inhibitors [2]. The small molecules derived from quaternized pyridine, quinoline and isoquinoline were designed as AChE inhibitors. Their ability to inhibit AChE or BChE was determined in vitro using IC50. The IC50 data were compared within each group of compounds with emphasis on selectivity AChE versus BChE. The overall study will be presented. The work was supported by Ministry of Defence of Czech Republic No. OVUOFVZ200805.(author)

Effects of pretreatment on the surface chemistry and pore size properties of nitrogen functionalized and alkylated granular activated carbon

Energy Technology Data Exchange (ETDEWEB)

Chen Jiajun [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082 (China); Zhai Yunbo, E-mail: ybzhai@hnu.edu.cn [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082 (China); Chen Hongmei; Li Caiting; Zeng Guangming; Pang Daoxiong; Lu Pei [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082 (China)

2012-12-15

Highlights: Black-Right-Pointing-Pointer The effects of pretreatment on the surface chemistry and pore sizes were studied. Black-Right-Pointing-Pointer Treated GAC was nitrogen functionalized and alkylated GAC also called modified GAC. Black-Right-Pointing-Pointer HNO{sub 3} pretreatment caused a slight decrease in surface area and microporosity. Black-Right-Pointing-Pointer The nitrogen percentage of modified GAC which pretreated by H{sub 2}O{sub 2} was 4.07%. Black-Right-Pointing-Pointer The pyridine of modified GAC which pretreated by urea-formaldehyde resin was 45.88%. - Abstract: In this paper, granular activated carbon (GAC) from coconut shell was pretreated by HNO{sub 3}, H{sub 2}O{sub 2} and urea-formaldehyde resin, respectively. Then the obtained materials were functionalized in the same way for nitrogen group, and then alkylated. Effects of pretreatment on the surface chemistry and pore size of modified GACs were studied. Surface area and micropore volume of modified GAC which pretreated by HNO{sub 3} were 723.88 m{sup 2}/g and 0.229 cm{sup 3}/g, respectively, while virgin GAC were 742.34 m{sup 2}/g and 0.276 cm{sup 3}/g. Surface area and micropore volume decrease of the modified GACs which pretreated by the others two methods were more drastically. The types of groups presented were analyzed by electrophoresis, Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). N-CH{sub 3} group and C=N group were detected on the surfaces of these three kinds of modified GACs. Results of XPS showed that the nitrogen functions of modified GAC which pretreated by H{sub 2}O{sub 2} was 4.07%, it was more than that of the others two pretreatment methods. However, the modified GAC which pretreated by urea-formaldehyde resin was fixed more pyridine structure, which structure percentage was 45.88%, in addition, there were more basic groups or charge on the surface than the others.

Combination of ensiling and fungal delignification as effective wheat straw pretreatment

DEFF Research Database (Denmark)

Thomsen, Sune T.; Londono, Jorge E. G.; Ambye-Jensen, Morten

2016-01-01

Background: Utilization of lignocellulosic feedstocks for bioenergy production in developing countries demands competitive but low-tech conversion routes. White-rot fungi (WRF) inoculation and ensiling are two methods previously investigated for low-tech pretreatment of biomasses such as wheat...

Carbon Nanotube Fiber Pretreatments for Electrodeposition of Copper

OpenAIRE

Hannula, Pyry-Mikko; Junnila, Minttu; Janas, Dawid; Aromaa, Jari; Forsén, Olof; Lundström, Mari

2018-01-01

There is increasing interest towards developing carbon nanotube-copper (CNT-Cu) composites due to potentially improved properties. Carbon nanotube macroscopic materials typically exhibit high resistivity, low electrochemical reactivity, and the presence of impurities, which impede its use as a substrate for electrochemical deposition of metals. In this research, different CNT fiber pretreatment methods, such as heat treatment, immersion in Watts bath, anodization, and exposure to boric acid (...

Structural changes of corn stover lignin during acid pretreatment.

Science.gov (United States)

Moxley, Geoffrey; Gaspar, Armindo Ribeiro; Higgins, Don; Xu, Hui

2012-09-01

In this study, raw corn stover was subjected to dilute acid pretreatments over a range of severities under conditions similar to those identified by the National Renewable Energy Laboratory (NREL) in their techno-economic analysis of biochemical conversion of corn stover to ethanol. The pretreated corn stover then underwent enzymatic hydrolysis with yields above 70 % at moderate enzyme loading conditions. The enzyme exhausted lignin residues were characterized by ³¹P NMR spectroscopy and functional moieties quantified and correlated to enzymatic hydrolysis yields. Results from this study indicated that both xylan solubilization and lignin degradation are important for improving the enzyme accessibility and digestibility of dilute acid pretreated corn stover. At lower pretreatment temperatures, there is a good correlation between xylan solubilization and cellulose accessibility. At higher pretreatment temperatures, lignin degradation correlated better with cellulose accessibility, represented by the increase in phenolic groups. During acid pretreatment, the ratio of syringyl/guaiacyl functional groups also gradually changed from less than 1 to greater than 1 with the increase in pretreatment temperature. This implies that more syringyl units are released from lignin depolymerization of aryl ether linkages than guaiacyl units. The condensed phenolic units are also correlated with the increase in pretreatment temperature up to 180 °C, beyond which point condensation reactions may overtake the hydrolysis of aryl ether linkages as the dominant reactions of lignin, thus leading to decreased cellulose accessibility.

Optimization of H2SO4-catalyzed hydrothermal pretreatment of rapeseed straw for bioconversion to ethanol

DEFF Research Database (Denmark)

Xuebin, Lu; Zhang, Y.; Angelidaki, Irini

2009-01-01

A central composite design of response surface method was used to optimize H2SO4-catalyzed hydrothermal pretreatment of rapeseed straw, in respect to acid concentration (0.5-2%), treatment time (5-20 min) and solid content (10-20%) at 180 degrees C. Enzymatic hydrolysis and fermentation were also...... content for 10 min at 180 degrees C was found to be the most optimal condition for pretreatment of rapeseed straw for ethanol production. After pretreatment at the optimal condition and enzymatic hydrolysis, 75.12% total xylan and 63.17% total glucan were converted to xylose and glucose, respectively...

Pretreatment on Corn Stover with Low Concentration of Formic Acid

DEFF Research Database (Denmark)

Xu, Jian; Thomsen, Mette Hedegaard; Thomsen, Anne Belinda

2009-01-01

the cellulose easily degraded into sugars and further fermented to ethanol. In this work, hydrothermal pretreatment on corn stover at 195 degrees for 15 min with and without lower concentration of formic acid was compared in terms of sugar recoveries and ethanol fermentation. For pretreatment with formic acid...... pretreatment without formic acid. Toxicity tests of liquor parts showed that there were no inhibitions found for both pretreatment conditions. After simultaneous saccharification and fermentation (SSF) of the pretreated corn stover with Baker's yeast, the highest ethanol yield of 76.5% of the theoretical...

Alkaline pretreatment of Mexican pine residues for bioethanol ...

African Journals Online (AJOL)

Alkaline pretreatment of Mexican pine residues for bioethanol production. ... Keywords: Lignocellulosic biomass, alkaline pretreatment, enzymatic hydrolysis, fermentable sugars, fermentation. African Journal of Biotechnology Vol. 12(31), pp.

Evaluation of stream crossing methods prior to gas pipeline construction

International Nuclear Information System (INIS)

Murphy, M.H.; Rogers, J.S.; Ricca, A.

1995-01-01

Stream surveys are conducted along proposed gas pipeline routes prior to construction to assess potential impacts to stream ecosystems and to recommend preferred crossing methods. Recently, there has been a high level of scrutiny from the Public Service Commission (PSC) to conduct these stream crossings with minimal effects to the aquatic community. PSC's main concern is the effect of sediment on aquatic biota. Smaller, low flowing or intermittent streams are generally crossed using a wet crossing technique. This technique involves digging a trench for the pipeline while the stream is flowing. Sediment control measures are used to reduce sediment loads downstream. Wider, faster flowing, or protected streams are typically crossed with a dry crossing technique. A dry crossing involves placing a barrier upstream of the crossing and diverting the water around the crossing location. The pipeline trench is then dug in the dry area. O'Brien and Gere and NYSEG have jointly designed a modified wet crossing for crossing streams that exceed maximum flows for a dry crossing, and are too wide for a typical wet crossing. This method diverts water around the crossing using a pumping system, instead of constructing a dam. The trench is similar to a wet crossing, with sediment control devices in place upstream and downstream. If streams are crossed during low flow periods, the pumping system will be able to reduce the majority of water flow and volume form the crossing area, thereby reducing ecological impacts. Evaluation of effects of this crossing type on the stream biota are currently proposed and may proceed when construction begins

A Score for Risk of Thrombolysis-Associated Hemorrhage Including Pretreatment with Statins

Directory of Open Access Journals (Sweden)

Hebun Erdur

2018-02-01

Full Text Available BackgroundSymptomatic intracranial hemorrhage (sICH after intravenous thrombolysis with recombinant tissue-plasminogen activator (rt-PA for acute ischemic stroke is associated with a poor functional outcome. We aimed to develop a score assessing risk of sICH including novel putative predictors—namely, pretreatment with statins and severe renal impairment.MethodsWe analyzed our local cohort (Berlin of patients receiving rt-PA for acute ischemic stroke between 2006 and 2016. Outcome was sICH according to ECASS-III criteria. A multiple regression model identified variables associated with sICH and receiver operating characteristics were calculated for the best discriminatory model for sICH. The model was validated in an independent thrombolysis cohort (Basel.ResultssICH occurred in 53 (4.0% of 1,336 patients in the derivation cohort. Age, baseline National Institutes of Health Stroke Scale, systolic blood pressure on admission, blood glucose on admission, and prior medication with medium- or high-dose statins were associated with sICH and included into the risk of intracranial hemorrhage score. The validation cohort included 983 patients of whom 33 (3.4% had a sICH. c-Statistics for sICH was 0.72 (95% CI 0.66–0.79 in the derivation cohort and 0.69 (95% CI 0.60–0.77 in the independent validation cohort. Inclusion of severe renal impairment did not improve the score.ConclusionWe developed a simple score with fair discriminating capability to predict rt-PA-related sICH by adding prior statin use to known prognostic factors of sICH. This score may help clinicians to identify patients with higher risk of sICH requiring intensive monitoring.

Dispositional study of opioids in mice pretreated with sympathomimetic agents.

Science.gov (United States)

Dambisya, Y M; Chan, K; Wong, C L

1992-08-01

Brain and plasma levels of morphine and codeine were determined by an assay method involving solid-phase extraction and ion-pair reversed phase HPLC. Detection was by a variable wavelength UV-detector (for codeine) and an amperometric electro-chemical detector (for morphine) coupled in series. Ephedrine or phenylpropanolamine pretreatment did not interfere with the plasma disposition of morphine, evidenced by overlapping plasma concentration-time profiles. Brain opioid levels were equally unaffected by sympathomimetic pretreatment. The relative ratios of brain to plasma concentrations at the time corresponding to the respective peak anti-nociceptive activity for morphine and codeine revealed no significant differences. It is concluded that single doses of ephedrine and phenylpropanolamine do not affect the disposition of morphine and codeine in mice.

Figure-ground segmentation based on class-independent shape priors

Science.gov (United States)

Li, Yang; Liu, Yang; Liu, Guojun; Guo, Maozu

2018-01-01

We propose a method to generate figure-ground segmentation by incorporating shape priors into the graph-cuts algorithm. Given an image, we first obtain a linear representation of an image and then apply directional chamfer matching to generate class-independent, nonparametric shape priors, which provide shape clues for the graph-cuts algorithm. We then enforce shape priors in a graph-cuts energy function to produce object segmentation. In contrast to previous segmentation methods, the proposed method shares shape knowledge for different semantic classes and does not require class-specific model training. Therefore, the approach obtains high-quality segmentation for objects. We experimentally validate that the proposed method outperforms previous approaches using the challenging PASCAL VOC 2010/2012 and Berkeley (BSD300) segmentation datasets.

Radioprotection by caffeine pre-treatment and post-treatment in the bone marrow chromosomes of mice given whole-body γ-irradiation

International Nuclear Information System (INIS)

Farooqi, Z.; Kesavan, P.C.

1992-01-01

The effect of caffeine given as pre- and post-treatment in mice exposed to whole-body γ-irradiation (1.5 Gy 60 Co γ-rays) was studied. The pre-treatment was either acute or chronic. The acute dose (5 mg/kg and 15 mg/kg body weight) was in the form of an injection given intraperitoneally, 30 min before irradiation. The chronic administration was in the form of caffeine solution (4.208x10 -3 M and 7.72x10 -4 M) contained in drinking water for 5 weeks prior to radiation exposure. The acute pre-treatment with caffeine reduced the radiation-induced frequency of chromosomal aberrations discernibly, whereas chronic pre-treatment afforded a much more significant degree of radioprotection. The caffeine post-treatment (5 mg/kg and 15 mg/kg body weight) was given in the form of an intraperitoneal injection to the mice immediately following whole-body γ-irradiation. It is noted that both post-treatment concentrations of caffeine also significantly reduced the frequency of chromosomal aberrations induced by γ-rays. These data are briefly discussed in terms of possible mechanistic considerations. (author). 33 refs.; 3 tabs

Radioprotection by caffeine pre-treatment and post-treatment in the bone marrow chromosomes of mice given whole-body [gamma]-irradiation

Energy Technology Data Exchange (ETDEWEB)

Farooqi, Z.; Kesavan, P.C. (Jawaharlal Nehru Univ., New Delhi (India). School of Life Sciences)

1992-10-01

The effect of caffeine given as pre- and post-treatment in mice exposed to whole-body [gamma]-irradiation (1.5 Gy [sup 60]Co [gamma]-rays) was studied. The pre-treatment was either acute or chronic. The acute dose (5 mg/kg and 15 mg/kg body weight) was in the form of an injection given intraperitoneally, 30 min before irradiation. The chronic administration was in the form of caffeine solution (4.208x10[sup -3] M and 7.72x10[sup -4] M) contained in drinking water for 5 weeks prior to radiation exposure. The acute pre-treatment with caffeine reduced the radiation-induced frequency of chromosomal aberrations discernibly, whereas chronic pre-treatment afforded a much more significant degree of radioprotection. The caffeine post-treatment (5 mg/kg and 15 mg/kg body weight) was given in the form of an intraperitoneal injection to the mice immediately following whole-body [gamma]-irradiation. It is noted that both post-treatment concentrations of caffeine also significantly reduced the frequency of chromosomal aberrations induced by [gamma]-rays. These data are briefly discussed in terms of possible mechanistic considerations. (author). 33 refs.; 3 tabs.

Evaluation of cognitive function in patients with limited small cell lung cancer prior to and shortly following prophylactic cranial irradiation

Energy Technology Data Exchange (ETDEWEB)

Komaki, Ritsuko; Meyers, Christina A; Shin, Dong M; Garden, Adam S; Byrne, Kevin; Nickens, Judy A; Cox, James D

1995-08-30

Purpose: Cognitive deficits after treatment for small cell lung cancer (SCLC) have been attributed to prophylactic cranial irradiation (PCI). A prospective study of neuropsychological function was undertaken to document the evolution and magnitude of neuropsychologic deficits. Methods and Materials: Thirty patients with limited stage SCLC who responded well (29 complete response (CR), 1 partial response (PR)) to combination chemotherapy plus thoracic irradiation or resection were studied with neuropsychological tests in the cognitive domains of intelligence, frontal lobe function, language, memory, visual-perception, and motor dexterity prior to a planned course of PCI. Nine patients had a neurologic history that could influence testing. Results: An unexpected 97% (29 out of 30) of patients had evidence of cognitive dysfunction prior to PCI. The most frequent impairment was verbal memory, followed by frontal lobe dysfunction, and fine motor incoordination. Of the patients with no prior neurologic or substance abuse history, 20 out of 21 (95%) had impairments on neuropsychological assessment. This neurologically normal group was just as impaired as the group with such a history with respect to delayed verbal memory and frontal lobe executive function. Eleven patients had neuropsychological testing 6 to 20 months after PCI; no significant differences were found from their pretreatment tests. Conclusions: A high proportion of neurologically normal patients with limited SCLC and favorable responses to combination chemotherapy have specific cognitive deficits before receiving PCI. Short-term (6 to 20 months) observations after PCI have shown no significant deterioration.

Evaluation of cognitive function in patients with limited small cell lung cancer prior to and shortly following prophylactic cranial irradiation

International Nuclear Information System (INIS)

Komaki, Ritsuko; Meyers, Christina A.; Shin, Dong M.; Garden, Adam S.; Byrne, Kevin; Nickens, Judy A.; Cox, James D.

1995-01-01

Purpose: Cognitive deficits after treatment for small cell lung cancer (SCLC) have been attributed to prophylactic cranial irradiation (PCI). A prospective study of neuropsychological function was undertaken to document the evolution and magnitude of neuropsychologic deficits. Methods and Materials: Thirty patients with limited stage SCLC who responded well (29 complete response (CR), 1 partial response (PR)) to combination chemotherapy plus thoracic irradiation or resection were studied with neuropsychological tests in the cognitive domains of intelligence, frontal lobe function, language, memory, visual-perception, and motor dexterity prior to a planned course of PCI. Nine patients had a neurologic history that could influence testing. Results: An unexpected 97% (29 out of 30) of patients had evidence of cognitive dysfunction prior to PCI. The most frequent impairment was verbal memory, followed by frontal lobe dysfunction, and fine motor incoordination. Of the patients with no prior neurologic or substance abuse history, 20 out of 21 (95%) had impairments on neuropsychological assessment. This neurologically normal group was just as impaired as the group with such a history with respect to delayed verbal memory and frontal lobe executive function. Eleven patients had neuropsychological testing 6 to 20 months after PCI; no significant differences were found from their pretreatment tests. Conclusions: A high proportion of neurologically normal patients with limited SCLC and favorable responses to combination chemotherapy have specific cognitive deficits before receiving PCI. Short-term (6 to 20 months) observations after PCI have shown no significant deterioration

Gemcitabine and capecitabine for heavily pre-treated metastatic colorectal cancer patients

DEFF Research Database (Denmark)

Spindler, Karen-Lise G; Pallisgaard, Niels; Andersen, Rikke F

2014-01-01

AIM: We investigated the efficacy and safety of capecitabine and gemcitabin (GemCap) in heavily pre-treated, therapy-resistant metastatic colorectal cancer (mCRC) patients and the clinical importance of cell-free DNA (cfDNA) measurement. PATIENTS AND METHODS: Patients' inclusion criteria included...

Alkaline/peracetic acid as a pretreatment of lignocellulosic biomass for ethanol fuel production

Science.gov (United States)

Teixeira, Lincoln Cambraia

Peracetic acid is a lignin oxidation pretreatment with low energy input by which biomass can be treated in a silo type system for improving enzymatic digestibility of lignocellulosic materials for ethanol production. Experimentally, ground hybrid poplar wood and sugar cane bagasse are placed in plastic bags and a peracetic acid solution is added to the biomass in different concentrations based on oven-dry biomass. The ratio of solution to biomass is 6:1; after initial mixing of the resulting paste, a seven-day storage period at about 20°C is used in this study. As a complementary method, a series of pre-pretreatments using stoichiometric amounts of sodium hydroxide and ammonium hydroxide based on 4-methyl-glucuronic acid and acetyl content in the biomass is been performed before addition of peracetic acid. The alkaline solutions are added to the biomass in a ratio of 14:1 solution to biomass; the slurry is mixed for 24 hours at ambient temperature. The above procedures give high xylan content substrates. Consequently, xylanase/beta-glucosidase combinations are more effective than cellulase preparations in hydrolyzing these materials. The pretreatment effectiveness is evaluated using standard enzymatic hydrolysis and simultaneous saccharification and cofermentation (SSCF) procedures. Hybrid poplar wood pretreated with 15 and 21% peracetic acid based on oven-dry weight of wood gives glucan conversion yields of 76.5 and 98.3%, respectively. Sugar cane bagasse pretreated with the same loadings gives corresponding yields of 85.9 and 93.1%. Raw wood and raw bagasse give corresponding yields of 6.8 and 28.8%, respectively. The combined 6% NaOH/15% peracetic acid pretreatments increase the glucan conversion yields from 76.5 to 100.0% for hybrid poplar wood and from 85.9 to 97.6% for sugar cane bagasse. Respective ethanol yields of 92.8 and 91.9% are obtained from 6% NaOH/15% peracetic acid pretreated materials using recombinant Zymomonas mobilis CP4/pZB5. Peracetic acid

Biomass torrefaction: A promising pretreatment technology for biomass utilization

Science.gov (United States)

Chen, ZhiWen; Wang, Mingfeng; Ren, Yongzhi; Jiang, Enchen; Jiang, Yang; Li, Weizhen

2018-02-01

Torrefaction is an emerging technology also called mild pyrolysis, which has been explored for the pretreatment of biomass to make the biomass more favorable for further utilization. Dry torrefaction (DT) is a pretreatment of biomass in the absence of oxygen under atmospheric pressure and in a temperature range of 200-300 degrees C, while wet torrrefaction (WT) is a method in hydrothermal or hot and high pressure water at the tempertures within 180-260 degrees C. Torrrefied biomass is hydrophobic, with lower moisture contents, increased energy density and higher heating value, which are more comparable to the characteristics of coal. With the improvement in the properties, torrefied biomass mainly has three potential applications: combustion or co-firing, pelletization and gasification. Generally, the torrefaction technology can accelerate the development of biomass utilization technology and finally realize the maximum applications of biomass energy.

Pre-treating dentin with chlorhexadine and CPP-ACP: self-etching and universal adhesive systems.

Science.gov (United States)

Dos Santos, Ricardo Alves; de Lima, Eliane Alves; Montes, Marcos Antônio Japiassu Resende; Braz, Rodivan

2016-12-01

Objective: The aim of the present study was to compare the effect of pre-treating dentin with chlorhexidine, at concentrations of 0.2% and 2%, and remineralizing paste containing CPP-ACP (MI Paste - GC) on the bond strength of adhesive systems. Material and methods: In total, 80 slides of dentin were used. These slides were 2 mm thick and were obtained from bovine incisors. Standard cavities were created using diamond bur number 3131. In the control groups, a Scotchbond Universal Adhesive (SUA) self-etching adhesive system of 3M ESPE and a Clearfil SE Bond (CSE) adhesive system of Kuraray were applied, following the manufacturer's instructions. In the other groups, dentin was pretreated with chlorhexidine (0.2% and 2%) for 1 min and with MI Paste for 3 min. The cavities were restored with Z350 XT resin (3M ESPE). After 24 h of storage, the push-out test was applied at a speed of 0.5 mm/min. Results: The different dentin pretreatment techniques did not affect the intra-adhesive bond strength. There was a difference between treatment with MI Paste and chlorhexidine 0.2% in favor of the SUA, with values of 15.22 and 20.25 Mpa, respectively. Conclusions: The different pretreatment methods did not alter the immediate bond strength to dentin. Differences were only recorded when comparing the adhesives.

Potential of Black Liquor of Potassium Hydroxide to Pretreat Corn Stover for Biomethane Production

Directory of Open Access Journals (Sweden)

Muhammad Abdul Hanan Siddhu

2016-04-01

Full Text Available Reducing the pretreatment cost of lignocellulosic biomass by utilizing alkali to alter its recalcitrant nature is an effective method for biofuel production. In this experiment, 1.5% KOH solution and its black liquor (spent liquor of KOH (BL were applied to pretreat corn stover (CS at a temperature of 20 °C to enhance the digestibility for anaerobic digestion (AD. Results showed no significant difference in weighted average methane content on the basis of experimental methane and biogas yields between BL-treated and original KOH-treated CS after AD. The BL process significantly increased the overall methane yield by 52.4% compared with untreated CS (135.2 mL/gVS, whereas no significant difference between the overall methane yields of 1.5% KOH-treated and BL-treated CS was observed. In addition, the BL process significantly saved water and KOH consumption, by 56.2% and 57.4%, respectively, compared with the 1.5% KOH pretreatment. Overall methane production was well explained by the modified Gompertz model. The physiochemical changes to CS after BL pretreatment were confirmed by SEM, FTIR, and XRD analyses. Our findings collectively suggest that recycling and reuse of KOH black liquor might be an efficient method for lignocellulosic biomass treatment and have the capability to reduce input costs in future AD processes.

Enzymatic Hydrolysis of Pretreated Fibre Pressed Oil Palm Frond by using Sacchariseb C6

Science.gov (United States)

Hashim, F. S.; Yussof, H. W.; Zahari, M. A. K. M.; Rahman, R. A.; Illias, R. M.

2017-06-01

Enzymatic hydrolysis becomes a prominent technology for conversion of cellulosic biomass to its glucose monomers that requires an action of cellulolytic enzymes in a sequential and synergistic manner. In this study, the effect of agitation speed, glucan loading, enzyme loading, temperature and reaction time on the production of glucose from fibre pressed oil palm frond (FPOPF) during enzymatic hydrolysis was screened by a half factorial design 25-1 using Response Surface Methodology (RSM). The FPOPF sample was first delignified by alkaline pretreatment at 4.42 (w/v) sodium hydroxide for an hour prior to enzymatic hydrolysis using commercial cellulase enzyme, Sacchariseb C6. The effect of enzymatic hydrolysis on the structural of FPOPF has been evaluated by Scanning Electron Microscopy (SEM) analysis. Characterization of raw FPOPF comprised of 4.5 extractives, 40.7 glucan, 26.1 xylan, 26.2 lignin and 1.8 ash, whereas for pretreated FPOPF gave 0.3 extractives, 61.4 glucan, 20.4 xylan, 13.3 lignin and 1.3 ash. From this study, it was found that the best enzymatic hydrolysis condition yielded 33.01 ± 0.73 g/L of glucose when performed at 200 rpm of agitation speed, 60 FPU/mL of enzyme loading, 4 (w/w) of glucan loading, temperature at 55 □ and 72 hours of reaction time. The model obtained was significant with p-value enzymatic hydrolysis from pretreated FPOPF produce high amount of glucose that enhances it potential for industrial application. This glucose can be further used to produce high-value products.

Source Localization by Entropic Inference and Backward Renormalization Group Priors

Directory of Open Access Journals (Sweden)

Nestor Caticha

2015-04-01

Full Text Available A systematic method of transferring information from coarser to finer resolution based on renormalization group (RG transformations is introduced. It permits building informative priors in finer scales from posteriors in coarser scales since, under some conditions, RG transformations in the space of hyperparameters can be inverted. These priors are updated using renormalized data into posteriors by Maximum Entropy. The resulting inference method, backward RG (BRG priors, is tested by doing simulations of a functional magnetic resonance imaging (fMRI experiment. Its results are compared with a Bayesian approach working in the finest available resolution. Using BRG priors sources can be partially identified even when signal to noise ratio levels are up to ~ -25dB improving vastly on the single step Bayesian approach. For low levels of noise the BRG prior is not an improvement over the single scale Bayesian method. Analysis of the histograms of hyperparameters can show how to distinguish if the method is failing, due to very high levels of noise, or if the identification of the sources is, at least partially possible.

AutoSOME: a clustering method for identifying gene expression modules without prior knowledge of cluster number

Directory of Open Access Journals (Sweden)

Cooper James B

2010-03-01

Full Text Available Abstract Background Clustering the information content of large high-dimensional gene expression datasets has widespread application in "omics" biology. Unfortunately, the underlying structure of these natural datasets is often fuzzy, and the computational identification of data clusters generally requires knowledge about cluster number and geometry. Results We integrated strategies from machine learning, cartography, and graph theory into a new informatics method for automatically clustering self-organizing map ensembles of high-dimensional data. Our new method, called AutoSOME, readily identifies discrete and fuzzy data clusters without prior knowledge of cluster number or structure in diverse datasets including whole genome microarray data. Visualization of AutoSOME output using network diagrams and differential heat maps reveals unexpected variation among well-characterized cancer cell lines. Co-expression analysis of data from human embryonic and induced pluripotent stem cells using AutoSOME identifies >3400 up-regulated genes associated with pluripotency, and indicates that a recently identified protein-protein interaction network characterizing pluripotency was underestimated by a factor of four. Conclusions By effectively extracting important information from high-dimensional microarray data without prior knowledge or the need for data filtration, AutoSOME can yield systems-level insights from whole genome microarray expression studies. Due to its generality, this new method should also have practical utility for a variety of data-intensive applications, including the results of deep sequencing experiments. AutoSOME is available for download at http://jimcooperlab.mcdb.ucsb.edu/autosome.

Morphologies and separation characteristics of polyphenyl sulfone-based solvent resistant nanofiltration membranes: Effect of polymer concentration in casting solution and membrane pretreatment condition

Energy Technology Data Exchange (ETDEWEB)

Sani, Nur Aimie Abdullah; Lau, Woei Jye; Ismail, Ahmad Fauzi [Universiti Teknologi Malaysia, Skudai (Malaysia)

2015-04-15

The performance of polyphenylsulfone (PPSU) solvent resistant nanofiltration (SRNF)-based flat sheet membranes prepared from phase inversion method was investigated by varying the concentration of polymer in the dope solution and condition of membrane pretreatment process. The membrane properties were characterized by SEM, FTIR, AFM and contact angle goniometer, while their performance was evaluated by measuring methanol flux and rejection of different molecular weight of dyes (ranging from 269 to 1,470 g/mol) in methanol. The experimental results showed that the polymer concentration has great impact not only on the final membrane morphology but also its separation characteristics. Increasing polymer concentration from 17 to 25wt% tended to suppress finger-like structure and more pear-like pores were developed, causing methanol flux to decrease. This can be explained by the decrease in molecular weight cut off (MWCO) of the membrane prepared at high polymer concentration. With respect to the effect of membrane pretreatment conditions, the rejection of membrane was negatively affected with longer immersion period in methanol solution prior to filtration experiment. The variation in membrane rejection can be attributed to the rearrangement of the polymer chain, which results in membrane swelling and/or change of membrane surface hydrophilicity.

Morphologies and separation characteristics of polyphenyl sulfone-based solvent resistant nanofiltration membranes: Effect of polymer concentration in casting solution and membrane pretreatment condition

International Nuclear Information System (INIS)

Sani, Nur Aimie Abdullah; Lau, Woei Jye; Ismail, Ahmad Fauzi

2015-01-01

The performance of polyphenylsulfone (PPSU) solvent resistant nanofiltration (SRNF)-based flat sheet membranes prepared from phase inversion method was investigated by varying the concentration of polymer in the dope solution and condition of membrane pretreatment process. The membrane properties were characterized by SEM, FTIR, AFM and contact angle goniometer, while their performance was evaluated by measuring methanol flux and rejection of different molecular weight of dyes (ranging from 269 to 1,470 g/mol) in methanol. The experimental results showed that the polymer concentration has great impact not only on the final membrane morphology but also its separation characteristics. Increasing polymer concentration from 17 to 25wt% tended to suppress finger-like structure and more pear-like pores were developed, causing methanol flux to decrease. This can be explained by the decrease in molecular weight cut off (MWCO) of the membrane prepared at high polymer concentration. With respect to the effect of membrane pretreatment conditions, the rejection of membrane was negatively affected with longer immersion period in methanol solution prior to filtration experiment. The variation in membrane rejection can be attributed to the rearrangement of the polymer chain, which results in membrane swelling and/or change of membrane surface hydrophilicity

Improving biogas production from microalgae by enzymatic pretreatment.

Science.gov (United States)

Passos, Fabiana; Hom-Diaz, Andrea; Blanquez, Paqui; Vicent, Teresa; Ferrer, Ivet

2016-01-01

In this study, enzymatic pretreatment of microalgal biomass was investigated under different conditions and evaluated using biochemical methane potential (BMP) tests. Cellulase, glucohydrolase and an enzyme mix composed of cellulase, glucohydrolase and xylanase were selected based on the microalgae cell wall composition (cellulose, hemicellulose, pectin and glycoprotein). All of them increased organic matter solubilisation, obtaining high values already after 6h of pretreatment with an enzyme dose of 1% for cellulase and the enzyme mix. BMP tests with pretreated microalgae showed a methane yield increase of 8 and 15% for cellulase and the enzyme mix, respectively. Prospective research should evaluate enzymatic pretreatments in continuous anaerobic reactors so as to estimate the energy balance and economic cost of the process. Copyright © 2015 Elsevier Ltd. All rights reserved.

Time dependent pre-treatment EPID dosimetry for standard and FFF VMAT.

Science.gov (United States)

Podesta, Mark; Nijsten, Sebastiaan M J J G; Persoon, Lucas C G G; Scheib, Stefan G; Baltes, Christof; Verhaegen, Frank

2014-08-21

Methods to calibrate Megavoltage electronic portal imaging devices (EPIDs) for dosimetry have been previously documented for dynamic treatments such as intensity modulated radiotherapy (IMRT) using flattened beams and typically using integrated fields. While these methods verify the accumulated field shape and dose, the dose rate and differential fields remain unverified. The aim of this work is to provide an accurate calibration model for time dependent pre-treatment dose verification using amorphous silicon (a-Si) EPIDs in volumetric modulated arc therapy (VMAT) for both flattened and flattening filter free (FFF) beams. A general calibration model was created using a Varian TrueBeam accelerator, equipped with an aS1000 EPID, for each photon spectrum 6 MV, 10 MV, 6 MV-FFF, 10 MV-FFF. As planned VMAT treatments use control points (CPs) for optimization, measured images are separated into corresponding time intervals for direct comparison with predictions. The accuracy of the calibration model was determined for a range of treatment conditions. Measured and predicted CP dose images were compared using a time dependent gamma evaluation using criteria (3%, 3 mm, 0.5 sec). Time dependent pre-treatment dose verification is possible without an additional measurement device or phantom, using the on-board EPID. Sufficient data is present in trajectory log files and EPID frame headers to reliably synchronize and resample portal images. For the VMAT plans tested, significantly more deviation is observed when analysed in a time dependent manner for FFF and non-FFF plans than when analysed using only the integrated field. We show EPID-based pre-treatment dose verification can be performed on a CP basis for VMAT plans. This model can measure pre-treatment doses for both flattened and unflattened beams in a time dependent manner which highlights deviations that are missed in integrated field verifications.

TU-FG-BRB-04: A New Optimization Method for Pre-Treatment Patient-Specific Stopping-Power by Combining Proton Radiography and X-Ray CT

International Nuclear Information System (INIS)

Collins-Fekete, C; Schulte, R; Beaulieu, L; Seco, J

2016-01-01

Purpose: The relative stopping power (RSP) uncertainty is the largest contributor to the range uncertainty in proton therapy. The purpose of this work is to develop a robust and systematic method that yields accurate patient specific RSPs by combining pre-treatment X-ray CT and daily proton radiography. Methods: The method is formulated as a penalized least squares optimization (PLSO) problem min(|Ax-B|). The matrix A represents the cumulative path-length crossed in each material computed by calculating proton trajectories through the X-ray CT. The material RSPs are denoted by x and B is the pRad, expressed as water equivalent thickness. The equation is solved using a convex-conic optimizer. Geant4 simulations were made to assess the feasibility of the method. RSP extracted from the Geant4 materials were used as a reference and the clinical HU-RSP curve as a comparison. The PLSO was first tested on a Gammex RMI-467 phantom. Then, anthropomorphic phantoms of the head, pelvis and lung were studied and resulting RSPs were evaluated. A pencil beam was generated in each phantom to evaluate the proton range accuracy achievable by using the optimized RSPs. Finally, experimental data of a pediatric head phantom (CIRS) were acquired using a recently completed experimental pCT scanner. Results: Numerical simulations showed precise RSP (<0.75%) for Gammex materials except low-density lung (LN-300) (1.2%). Accurate RSP have been obtained for the head (µ=−0.10%, 1.5σ=1.12%), lung (µ=−0.33, 1.5σ=1.02%) and pelvis anthropomorphic phantoms (µ=0.12, 1.5σ=0,99%). The range precision has been improved with an average R80 difference to the reference (µ±1.5σ) of −0.20±0.35%, −0.47±0.92% and −0.06±0.17% in the head, lung and pelvis phantoms respectively, compared to the 3.5% clinical margin. Experimental HU-RSP curve have been produced on the CIRS pediatric head. Conclusion: The proposed PLSO with prior knowledge X-ray CT shows promising potential (R80 σ<1.0% over

Pre-treating water with non-thermal plasma

Science.gov (United States)

Cho, Young I.; Fridman, Alexander; Rabinovich, Alexander; Cho, Daniel J.

2017-07-04

The present invention consists of a method of pre-treatment of adulterated water for distillation, including adulterated water produced during hydraulic fracturing ("fracking") of shale rock during natural gas drilling. In particular, the invention is directed to a method of treating adulterated water, said adulterated water having an initial level of bicarbonate ion in a range of about 250 ppm to about 5000 ppm and an initial level of calcium ion in a range of about 500 ppm to about 50,000 ppm, said method comprising contacting the adulterated water with a non-thermal arc discharge plasma to produce plasma treated water having a level of bicarbonate ion of less than about 100 ppm. Optionally, the plasma treated water may be further distilled.

Effect of pomegranate juice pre-treatment on the transport of carbamazepine across rat intestine

Directory of Open Access Journals (Sweden)

D Adukondalu

2010-12-01

Full Text Available "n  "nBackground and the purpose of the study: Many drug substances along with a variety of naturally occurring dietary or herbal components interact with the CYP enzyme system.The present study was aimed to investigate the effect of pomegranate juice pre-treatment on the transport of carbamazepine across the rat intestine "nMethods: The transport of carbamazepine across different parts of rat intestine was studied by everted and non-everted sac methods. The control and pomegranate juice (10 ml Kg-1 for 7 days pre-treated rats were sacrificed and isolated the intestine. The sacs of intestine were prepared, treated with carbamazepine solution and then placed in dulbeccos buffer. Samples were collected periodically and the drug content was estimated using HPLC. Results and conclusion: The results show that there was a significant (p<0.05 difference in the transport of carbamazepine from the intestinal sacs of pretreated with pomegranate juice and control. It seems that pomegranatejuice might have induced CYP3A4enzymes and hence drug is extensively metabolized.

Activation of glassy carbon electrodes by photocatalytic pretreatment

Energy Technology Data Exchange (ETDEWEB)

Dumanli, Onur [Department of Chemistry, Faculty of Science and Art, Ondokuz Mayis University, Kurupelit, 55139 Samsun (Turkey); Onar, A. Nur [Department of Chemistry, Faculty of Science and Art, Ondokuz Mayis University, Kurupelit, 55139 Samsun (Turkey)], E-mail: nonar@omu.edu.tr

2009-11-01

This paper describes a simple and rapid photocatalytic pretreatment procedure that removes contaminants from glassy carbon (GC) surfaces. The effectiveness of TiO{sub 2} mediated photocatalytic pretreatment procedure was compared to commonly used alumina polishing procedure. Cyclic voltammetric and chronocoulometric measurements were carried out to assess the changes in electrode reactivity by using four redox systems. Electrochemical measurements obtained on photocatalytically treated GC electrodes showed a more active surface relative to polished GC. In cyclic voltammograms of epinephrine, Fe(CN){sub 6}{sup 3-/4-} and ferrocene redox systems, higher oxidation and reduction currents were observed. The heterogeneous electron transfer rate constants (k{sup o}) were calculated for Fe(CN){sub 6}{sup 3-/4-} and ferrocene which were greater for photocatalytic pretreatment. Chronocoulometry was performed in order to find the amount of adsorbed methylene blue onto the electrode and was calculated as 0.34 pmol cm{sup -2} for photocatalytically pretreated GC. The proposed photocatalytic GC electrode cleansing and activating pretreatment procedure was more effective than classical alumina polishing.

Enhanced Dissolution of Platinum Group Metals Using Electroless Iron Deposition Pretreatment

Science.gov (United States)

Taninouchi, Yu-ki; Okabe, Toru H.

2017-12-01

In order to develop a new method for efficiently recovering platinum group metals (PGMs) from catalyst scraps, the authors investigated an efficient dissolution process where the material was pretreated by electroless Fe deposition. When Rh-loaded alumina powder was kept in aqua regia at 313 K (40 °C) for 30 to 60 minutes, the Rh hardly dissolved. Meanwhile, after electroless Fe plating using a bath containing sodium borohydride and potassium sodium tartrate as the reducing and complexing agents, respectively, approximately 60 pct of Rh was extracted by aqua regia at 313 K (40 °C) after 30 minutes. Furthermore, when heat treatment was performed at 1200 K (927 °C) for 60 minutes in vacuum after electroless plating, the extraction of Rh approached 100 pct for the same leaching conditions. The authors also confirmed that the Fe deposition pretreatment enhanced the dissolution of Pt and Pd. These results indicate that an effective and environmentally friendly process for the separation and extraction of PGMs from catalyst scraps can be developed utilizing this Fe deposition pretreatment.

Survey of Lignin-Structure Changes and Depolymerization during Ionic Liquid Pretreatment

Energy Technology Data Exchange (ETDEWEB)

Dutta, Tanmoy; Isern, Nancy G.; Sun, Jian; Wang, Eileen; Hull, Sarah; Cort, John R.; Simmons, Blake A.; Singh, Seema

2017-09-26

A detailed study of chemical changes in lignin structure during the ionic liquid (IL) pretreatment process is not only pivotal for understanding and overcoming biomass recalcitrance during IL pretreatment, but also is necessary for designing new routes for lignin valorization. Chemical changes in lignin were systematically studied as a function of pretreatment temperature, time and type of IL used. Kraft lignin was used as the lignin source and common pretreatment conditions were employed using three different ILs of varying chemical structure in terms of acidic or basic character. The chemical changes in the lignin structure due to IL pretreatment processes were monitored using 1H-13C HSQC NMR, 31P NMR, elemental analysis, GPC, FT-IR, and the depolymerized products were analyzed using GC-MS. Although pretreatment in acidic IL, triethylammonium hydrogensulfate ([TEA][HSO4]) results in maximum decrease in β-aryl ether bond, maximum dehydration and recondensation pathways were also evident, with the net process showing a minimum decrease in the molecular weight of regenerated lignin. However, 1-ethyl-3-methylimidazolium acetate ([C2C1Im][OAc]) pretreatment yields a smaller decrease in the β-aryl ether content along with minimum evidence of recondensation, resulting in the maximum decrease in the molecular weight. Cholinium lysinate ([Ch][Lys]) pretreatment shows an intermediate result, with moderate depolymerization, dehydration and recondensation observed. The depolymerization products after IL pretreatment are found to be a function of the pretreatment temperature and the specific chemical nature of the IL used. At higher pretreatment temperature, [Ch][Lys] pretreatment yields guaiacol, [TEA][HSO4] yields guaiacylacetone, and [C2C1Im][OAc] yields both guaiacol and guaiacylacetone as major products. These results clearly indicate that the changes in lignin structure as well as the depolymerized product profile depend on the pretreatment conditions and the nature

Biorefining of wheat straw: accounting for the distribution of mineral elements in pretreated biomass by an extended pretreatment – severity equation

DEFF Research Database (Denmark)

Le, Duy Michael; Sørensen, Hanne Risbjerg; Knudsen, Niels Ole

2014-01-01

Background: Mineral elements present in lignocellulosic biomass feedstocks may accumulate in biorefinery process streams and cause technological problems, or alternatively can be reaped for value addition. A better understanding of the distribution of minerals in biomass in response to pretreatment...... factors is therefore important in relation to development of new biorefinery processes. The objective of the present study was to examine the levels of mineral elements in pretreated wheat straw in response to systematic variations in the hydrothermal pretreatment parameters (pH, temperature......) Silicon, iron, copper, aluminum correlated with lignin and cellulose levels, but the levels of these constituents showed no severity-dependent trends. For the first group, an expanded pretreatment-severity equation, containing a specific factor for each constituent, accounting for variability due...

Pretreatment procedures

International Nuclear Information System (INIS)

Anon.

1989-01-01

It is frequently in the patient's best interest that radiation treatments are initiated soon after the decision to treat is made. However, it is essential to good radiation therapy that the patient's treatment course be planned and beam-modifying devices be fabricated with utmost care prior to treatment. The objectives of the treatment, along with the treatment parameters and techniques necessary to achieve these objectives, must be discussed prior to initiating planning procedures. Determination of the target volume is made by the radiation oncologist; this is based on knowledge of the history of the tumor, the patterns of spread of the disease, and on diagnostic findings during the work-up of each patient. It is then necessary to obtain several measurements of the patient and also to identify the position of the target volume and of adjacent normal organs with respect to known external skin marks before the actual treatment planning is begun. Such localization can be done through several methods. The two most commonly used methods are radiographic and computed tomography (CT), both of which are discussed in this chapter. The measurements often include contours of the patient's external surface, usually in the axial plane of the central axis of the beam, and often in multiple levels within the region to be treated. Three dimensional localization and treatment planning requires thorough understanding of geometry as well as of patient positioning and immobilization. This chapter attempts to clarify some of these complicated but essential preparations for treatment

Effects of Different Pretreatments to Fresh Fruit on Chemical and Thermal Characteristics of Crude Palm Oil.

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Tang, Minmin; Xia, Qiuyu; Holland, Brendan J; Wang, Hui; Zhang, Yufeng; Li, Rui; Cao, Hongxing

2017-12-01

This study selected 5 methods, including boiling, hot air drying, high-pressurized steam, freezing, and microwave radiation to pretreat fresh oil palm fruit before solvent extraction of the oil. Using fresh fruit as a control, the pretreatment methods were compared for the effects on the activity of the 2 main enzymes in the fruit and some physicochemical properties of the crude palm oil. The results indicated, although all the 5 pretreatments could inactivate lipase and peroxidase in the treated flesh significantly (P oils. The crude oil from frozen fruit contained significantly more vitamin E (37829.33 ppm) than previously reported. Microwave radiation was shown to significantly decrease the free fatty acid content and the peroxide value, while increasing the oxidative stability index. Thermal behaviors of the oils were significantly different to each other with the exception a few parameters (P < 0.05). © 2017 Institute of Food Technologists®.

Making lignin accessible for anaerobic digestion by wet-explosion pretreatment

DEFF Research Database (Denmark)

Ahring, Birgitte Kiær; Biswas, Rajib; Ahamed, Aftab

2015-01-01

of lignin during anaerobic digestion processes. The pretreatment of feedlot manure was performed in a 10 L reactor at 170 C for 25 min using 4 bars oxygen and the material was fed to a continuous stirred tank reactor operated at 55 C for anaerobic digestion. Methane yield of untreated and pretreated...... material was 70 ± 27 and 320 ± 36 L/kg-VS/day, respectively, or 4.5 times higher yield as a result of the pretreatment. Aliphatic acids formed during the pretreatment were utilized by microbes. 44.4% lignin in pretreated material was actually converted in the anaerobic digestion process compared to 12...

Enamel pretreatment with Er:YAG laser: effects on the microleakage of fissure sealant in fluorosed teeth

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Mahtab Memarpour,

2014-08-01

Full Text Available Objectives The purpose of this in vitro study was to evaluate the microleakage and penetration of fissure sealant in permanent molar teeth with fluorosis after pretreatment of the occlusal surface. Materials and Methods A total of 120 third molars with mild dental fluorosis were randomly divided into 6 groups (n = 20. The tooth surfaces were sealed with an unfilled resin fissure sealant (FS material. The experimental groups included: 1 phosphoric acid etching (AE + FS (control; 2 AE + One-Step Plus (OS, Bisco + FS; 3 bur + AE + FS; 4 bur + AE + OS + FS; 5 Er:YAG laser + AE + FS; and 6 Er:YAG laser + AE + OS + FS. After thermocycling, the teeth were immersed in 0.5% fuchsin and sectioned. Proportions of mircoleakage (PM and unfilled area (PUA were measured by digital microscope. Results Overall, there were significant differences among all groups in the PM (p = 0.00. Group 3 showed the greatest PM, and was significantly different from groups 2 to 6 (p < 0.05. Group 6 showed the lowest PM. Pretreatment with Er:YAG with or without adhesive led to less PM than bur pretreatment. There were no significant differences among groups in PUA. Conclusions Conventional acid etching provided a similar degree of occlusal seal in teeth with fluorosis compared to those pretreated with a bur or Er:YAG laser. Pretreatment of pits and fissures with Er:YAG in teeth with fluorosis may be an alternative method before fissure sealant application.

Enhancing sludge biodegradability and volatile fatty acid production by tetrakis hydroxymethyl phosphonium sulfate pretreatment.

Science.gov (United States)

Wu, Qing-Lian; Guo, Wan-Qian; Bao, Xian; Yin, Ren-Li; Feng, Xiao-Chi; Zheng, He-Shan; Luo, Hai-Chao; Ren, Nan-Qi

2017-09-01

A new pretreatment method based on tetrakis hydroxymethyl phosphonium sulfate (THPS) biocide was tried to enhance sludge disintegration, and improved sludge biodegradability and subsequent volatile fatty acid (VFA) production. Sludge activity decreased to less than 10% after 2 days pretreatment using 20mg/g-TSS THPS, which also obviously destroyed EPS and cell membrane, and dissolved more biodegradable substances (48.8%) than raw sludge (19.7%). Moreover, 20mg/g-TSS THPS pretreatment shortened fermentation time to 4days and improved VFA production to 2778mg COD/L (4.35 times than that in control). Therein, the sum of n-butyric, n-valeric and iso-valeric acids unexpectedly accounted for 60.5% of total VFA (only 20.1% of that in control). The more high molecular weight VFAs (C4-C5) than low molecular VFAs (C2-C3) resulted from THPS pretreatment benefited to subsequent medium-chain volatile acids (C6-C12) generation to realize the separation and recovery of organic carbon more efficiently. Copyright © 2017. Published by Elsevier Ltd.

Investigations of the in-sacco digestibility of variously pretreated and γ-irradiated wheat straw