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Sample records for brazilian silica rice

Amorphous silica from rice husk at various temperatures

International Nuclear Information System (INIS)

Javed, S.J.; Feroze, N.; Tajwar, S.

2008-01-01

Rice husk is being used as a source of energy in many heat generating system because of its high calorific value and its availability in many rice producing areas. Rice husk contains approximately 20% silica which is presented in hydrated form. This hydrated silica can be retrieved as amorphous silica under controlled thermal conditions. Uncontrolled burning of rice husk produces crystalline silica which is not reactive silica but can be used as filler in many applications. Amorphous silica is reactive silica which has better market value due to its reactive nature in process industry. The present study deals with the production of amorphous silica at various temperatures from rice husk. Various ashes were prepared in tube furnace by changing the burning temperatures for fixed time intervals and analyzed by XRD. It has been observed that for two hours calculation's of rice husk renders mostly amorphous silica at 650 degree C where as at higher temperatures crystalline silica was obtained. (author)
Extracting silica from rice husk treated with potassium permanganate

International Nuclear Information System (INIS)

Javed, S.H.; Naveed, S.

2008-01-01

As an agro-waste material the rice husk is abundantly available is rice growing areas. In many areas rice husk after burning involves disposal problems because of higher quantities of silica present in it. Rice husk contains about 20 per cent silica, which is present in hydrated amorphous form. On thermal treatment the silica converts into crystobalite, which is a crystalline form of silica. However amorphous silica can be produced under controlled conditions ensuring high reactivity and large surface area. Leaching the rice husk with organic acids and alkalies removes the metallic impurities from its surface. How a dilute solution of potassium permanganate affects the rice husk is the subject of this research paper. The rice husk was treated with the dilute solution of potassium permanganate at room temperature and then analyzed by SEM, TGA and the ash by analytical treatment after burning under controlled temperature. The SEM results revealed that the protuberances of the rice husk were eaten away by the solution of potassium permanganate. Pyrolysis of rice husks showed that the thermal degradation of the treated rice husk was faster than the untreated rice husk where as analytical results confirmed the presence of more amorphous silica than untreated rice husk. (author)
Preparation and characterization of rice hull silica products

International Nuclear Information System (INIS)

Quirit, Leni L.; Llaguno, Elma C.; Pagdanganan, Fernando C.; Hernandez, Karen N.

2008-01-01

Rice hull is an abundant agricultural waste material which could be a renewable energy source when combusted. The combustion residue (called rice hull ash or RHA) contains a significant amount (20% of the hull) of potentially high grade silica. Silica gels prepared from rice hull were found to have properties comparable to two commercial desiccant silica gels (Blue Merck and FNG-A) in terms of chemical and amorphous structure, surface area, desiccant characteristics, microstructure and heats of adsorption. These properties were determined from water vapor adsorption measurements, electron microscopy, and from infrared and x-ray diffraction spectra. The acid treated rice hull gels were found to have fewer elemental impurities detected by qualitative x-ray fluorescence, compared to the commercial gels. Thermogravimetric analysis (TGA) data showed that this technique can also be used to indirectly compare impurity levels in the samples, in terms of the amorphous to crystalline phase transition. Using an improved acid treatment method, a silica gel sample was prepared from rice hull and compared to three commercial chromatographic silica gels using quantitative elemental x-ray fluorescence analysis. Elemental levels in the rice hull gel were within the range of levels or close to the detection limits of corresponding elements in the chromatographic gels. Water vapor adsorption, x-ray diffraction, infrared spectroscopy and scanning electron microscopy showed that the rice hull gel was similar to the commercial chromatographic silica gel Davison 12. Zeolites are crystalline aluminosilicates used as molecular sieves for purification and catalytic purposes. Zeolites X and Y were synthesized from rice hull silica gel and aluminum hydroxide. For comparison, controls were synthesized from commercial silica gel. The samples and controls exhibited characteristics infrared peaks corresponding to the vibrations of the TO 4 (T=Si, Al) of the zeolite framework. The x
Mesoporous Silica from Rice Husk Ash

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S.A. Mandavgane

2010-12-01

Full Text Available Mesoporous silica is used as a raw material in several areas: in preparation of catalysts, in inks, as aconcrete hardening accelerator, as a component of detergents and soaps, as a refractory constituent etc.Sodium silicate is produced by reacting rice hull ash (RHA with aqueous NaOH and silica is precipitatedfrom the sodium silicate by acidification. In the present work, conversion of about 90% of silica containedin RHA into sodium silicate was achieved in an open system at temperatures of about 100 °C. The resultsshowed that silica obtained from RHA is mesoporous, has a large surface area and small particle size.Rice Husk is usually mixed with coal and this mixture is used for firing boilers. The RHA therefore, usuallycontains carbon particles. Activated carbon embedded on silica has been prepared using the carbon alreadypresent in RHA. This carbon shows good adsorption capacity. ©2010 BCREC UNDIP. All rights reserved(Received: 25th April 2010, Revised: 17th June 2010, Accepted: 24th June 2010[How to Cite: V.R. Shelke, S.S. Bhagade, S.A. Mandavgane. (2010. Mesoporous Silica from Rice Husk Ash. Bulletin of Chemical Reaction Engineering and Catalysis, 5 (2: 63-67. doi:10.9767/bcrec.5.2.793.63-67
Mesoporous Silica from Rice Husk Ash

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V.R. Shelke

2011-01-01

Full Text Available Mesoporous silica is used as a raw material in several areas: in preparation of catalysts, in inks, as a concrete hardening accelerator, as a component of detergents and soaps, as a refractory constituent etc. Sodium silicate is produced by reacting rice hull ash (RHA with aqueous NaOH and silica is precipitated from the sodium silicate by acidification. In the present work, conversion of about 90% of silica contained in RHA into sodium silicate was achieved in an open system at temperatures of about 100 °C. The results showed that silica obtained from RHA is mesoporous, has a large surface area and small particle size. Rice Husk is usually mixed with coal and this mixture is used for firing boilers. The RHA therefore, usually contains carbon particles. Activated carbon embedded on silica has been prepared using the carbon already present in RHA. This carbon shows good adsorption capacity. ©2010 BCREC UNDIP. All rights reserved(Received: 25th April 2010, Revised: 17th June 2010, Accepted: 24th June 2010[How to Cite: V.R. Shelke, S.S. Bhagade, S.A. Mandavgane. (2010. Mesoporous Silica from Rice Husk Ash. Bulletin of Chemical Reaction Engineering and Catalysis, 5 (2: 63-67. doi:10.9767/bcrec.5.2.793.63-67][DOI: http://dx.doi.org/10.9767/bcrec.5.2.793.63-67
Microbial Activity and Silica Degradation in Rice Straw

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Kim, Esther Jin-kyung

Abundantly available agricultural residues like rice straw have the potential to be feedstocks for bioethanol production. Developing optimized conditions for rice straw deconstruction is a key step toward utilizing the biomass to its full potential. One challenge associated with conversion of rice straw to bioenergy is its high silica content as high silica erodes machinery. Another obstacle is the availability of enzymes that hydrolyze polymers in rice straw under industrially relevant conditions. Microbial communities that colonize compost may be a source of enzymes for bioconversion of lignocellulose to products because composting systems operate under thermophilic and high solids conditions that have been shown to be commercially relevant. Compost microbial communities enriched on rice straw could provide insight into a more targeted source of enzymes for the breakdown of rice straw polysaccharides and silica. Because rice straw is low in nitrogen it is important to understand the impact of nitrogen concentrations on the production of enzyme activity by the microbial community. This study aims to address this issue by developing a method to measure microbial silica-degrading activity and measure the effect of nitrogen amendment to rice straw on microbial activity and extracted enzyme activity during a high-solids, thermophilic incubation. An assay was developed to measure silica-degrading enzyme or silicase activity. This process included identifying methods of enzyme extraction from rice straw, identifying a model substrate for the assay, and optimizing measurement techniques. Rice straw incubations were conducted with five different levels of nitrogen added to the biomass. Microbial activity was measured by respiration and enzyme activity. A microbial community analysis was performed to understand the shift in community structure with different treatments. With increased levels of nitrogen, respiration and cellulose and hemicellulose degrading activity
Obtaining high purity silica from rice hulls

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José da Silva Júnior

2010-01-01

Full Text Available Many routes for extracting silica from rice hulls are based on direct calcining. These methods, though, often produce silica contaminated with inorganic impurities. This work presents the study of a strategy for obtaining silica from rice hulls with a purity level adequate for applications in electronics. The technique is based on two leaching steps, using respectively aqua regia and Piranha solutions, which extract the organic matrix and inorganic impurities. The material was characterized by Fourier-transform infrared spectroscopy (FTIR, powder x-ray diffraction (XRD, x-ray fluorescence (XRF, scanning electron microscopy (SEM, particle size analysis by laser diffraction (LPSA and thermal analysis.
High Purity Silica Production from Rice Husk Ash

International Nuclear Information System (INIS)

Yaminn Lwin; April Nwayy Nwayy Htett

2010-12-01

In this research, two types of raw material source, rice husk and rice husk ash, were used. Among the rice husk samples, taungpyan sample was chosen because it contains the maximum silica content and treated with (1,3,5) wt% sulphuric acid (96% concentration) and citric acid (99% concentration). These acid treated taungpyan samples and nonacid treated taungpyan sample were burned at 900C for 30 min. For rice husk ash samples, ash samples from fluidized combustor, fluidized gasifier and brick factory were collected. All of the rice husk ash samples were purified by alkaline extraction method with (2-3) N NaOH solution and followed by acid precipitation method with 5 N H2SO4 solution. According to the analysis and characterization, acid treated taungpyan sample (5 wt% citric acid) with the highest silica content (99.906 wt% and crystallization form) was obtained.
Characteristics of silica rice husk ash from Mojogedang Karanganyar Indonesia

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Suryana, R.; Iriani, Y.; Nurosyid, F.; Fasquelle, D.

2018-05-01

Indonesia is one of the countries in the world as the most abundant rice producer. Many researchers have demonstrated that the highest composition in the rice husk ash (RHA) is silica. Some of the advantages in utilizing silica as the raw material is the manufacture of ceramics, zeolite synthesis, fabrication of glass, electronic insulator materials, and as a catalyst. The amount of silica from rice husk ash is different for each region. Therefore, the study of silica from RHA is still promising, especially rice organic fertilizers. In this study, the rice came from Mojogedang Karanganyar Indonesia. Rice husk was dried under the solar radiation. Then the rice husk was heated in two steps: the first step at a temperature of 300°C and the second step at a temperature of 1200°C with a holding time at 2 h and 1 h, respectively. Furthermore, the temperature of the second step was varied at 1400 °C and 1600 °C. This heating process produced RHA. The content of RHA was observed on the EDAX spectrums while the morphology was observed from SEM images. The crystal structure of RHA was determined from XRD spectrums. The EDAX spectrums showed that RHA composition was dominated by elements Si and O for all the heating temperature. SEM images showed an agglomeration towards larger domains as heating temperatures increase. Analysis of XRD spectra is polycrystalline silica formed with the significant crystal orientation at 101, 102 and 200. The intensity of 101 increases significantly with increasing temperature. It is concluded that the crystal growth in the direction of 101 is preferred.
Characterization of amorphous silica obtained from KMnO/sub 4/ treated rice husk

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Javed, S.H.; Naveed, S.; Ramzan, N.

2010-01-01

Rice husk (RH) is available in large quantities in many rice producing areas of Pakistan. The use of rice husk as a fuel in heat generating systems adds to environmental pollution. Rice husk contains approximately 20 % silica which exists in hydrated form. This silica can be retrieved as amorphous silica under proper oxidizing conditions. In present study rice husk was treated with various dosages of potassium permanganate before subjecting to thermal treatment. Potassium permanganate acts as oxidizing agent during combustion process. Various ash samples were prepared by varying the potassium permanganate concentrations and the burning temperatures over long periods. Ash produced was characterized by XRD, FTIR and other analytical methods. It has been observed that low dosages of KMnO/sub 4/ favors the formation of amorphous silica along with low carbon contents. (author)
Characterisation of silica derived from rice husk (Muar, Johor, Malaysia) decomposition at different temperatures

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Azmi, M. A.; Ismail, N. A. A.; Rizamarhaiza, M.; W. M. Hasif. A. A., K.; Taib, H.

2016-07-01

Rice husk was thermally decomposed to yield powder composed of silica (SiO2). Temperatures of 700°C and 1000°C were chosen as the decomposition temperatures. X-Ray Diffraction (XRD), X-Ray Florescence (XRF), Fourier Transform Infrared (FTIR), and Field Emission Scanning Electron Microscope (FESEM) analyses were conducted on a synthetic silica powder (SS-SiO2) and the rice husk ash as for the comparative characterisation study. XRD analyses clearly indicated that the decomposed rice husk yielded silica of different nature which are Crystalline Rice Husk Silica (C-RHSiO2) and Amorphous Rice Husk Silica (A-RHSiO2). Moreover, it was found that SS-SiO2 was of Quartz phase, C-RHSiO2 was of Trydimite and Cristobalite. Through XRF detection, the highest SiO2 purity was detected in SS-SiO2 followed by C-RHSiO2 and A-RHSiO2 with purity percentages of 99.60%, 82.30% and 86.30% respectively. FTIR results clearly indicated silica (SiO2) bonding 1056, 1064, 1047, 777, 790 and 798 cm-1) increased as the crystallinity silica increased. The Cristobalite phase was detected in C-RH SiO2 at the wavelength of 620 cm-1. Morphological features as observed by FESEM analyses confirmed that, SS-SiO2 and C-RH SiO2 showed prominent coarse granular morphology.
Synthesis and Characterizations of Fine Silica Powder from Rice Husk Ash

International Nuclear Information System (INIS)

Khin Muyar Latt

2011-12-01

The silica content of rice husk ash obtained from the uncontrolled burning temperature of gasifier was 90.4%. The obtained rice husk ash was an amorphous form of silica with low crystallization by XRD. The sodium hydroxide solution, 1.5N, 2N, 2.5N and 3N, respectively was used to prepare sodium silicate solution by extraction method. The product silica was produced by acid precipitation method used 4.5N, 5.5N and 6.5N sulphuric acid solution. The highest yield percent of product silica extraced by 2.5N sodium hydroxide solution at 5N sulphuric acid solution was 88.84%. The crystallize size of product silica containing silicalite as a source of silica was 86nm at this condition. The fine silica powder was produced by acid refluxing mothod used 5.5N, 6N and 6.5N hydrochloric acid solution. 98% of pure fine silica powder can be produced from the product silica by refluxing method. The crystallize size of fine silica powder was 54nm. The distribution of the crystallize size of product silica powder could be found uniform in size and agglomeration. The Fourier Transform Infrared Spectra indicate the hydrogen bonded silinol groups and siloxane groups in product silica and fine silica powder.
Porous silica from rice husk ash for tundish lining

International Nuclear Information System (INIS)

Ahmed, Y.M.Z; Ewais, E.M.

2007-01-01

Type of materials as well as its compressive strength and degree of porosity are the determinal parameters for deciding the suitability of its usage as lining for tundish in continuous casting of steel. Silica is one of the materials suitable for such application. High porosity degree with high compressive strength of its compacts is special demands for increasing its efficiency. The suitability of producing porous silica compacts from the combustion of rice husk ash (RHA) appropriate for this application is the objective of the present work. Experimental design technique was used to evaluate the effect of different parameters (i.e. firing temperature, time and compaction pressure) controlling both porosity degree and compressive strength of rice husk ash compacts. The results revealed that while the porosity degree of the compacts decreased with increasing the entire studied parameters, its compressive strength exhibits another trend especially at lower soaking time. At lower soaking time, increasing firing temperature leads to a slight decrease in the compressive strength and then increased thereafter. Porous silica compacts having 30% porosity and > 25 kg/cm/sup 2/ compressive strength suitable for tundish lining could obtain from the combustion of rice husk ash compacts. (author)
Characterisation of silica derived from rice husk (Muar, Johor, Malaysia) decomposition at different temperatures

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Azmi, M. A.; Ismail, N. A. A.; Rizamarhaiza, M.; Hasif, W. M. K. A. A.; Taib, H., E-mail: hariati@uthm.edu.my [Faculty of Mechanical and Manufacturing Engineering, Universiti Tun Hussein Onn Malaysia, 86400 Batu Pahat, Johor (Malaysia)

2016-07-19

Rice husk was thermally decomposed to yield powder composed of silica (SiO{sub 2}). Temperatures of 700°C and 1000°C were chosen as the decomposition temperatures. X-Ray Diffraction (XRD), X-Ray Florescence (XRF), Fourier Transform Infrared (FTIR), and Field Emission Scanning Electron Microscope (FESEM) analyses were conducted on a synthetic silica powder (SS-SiO{sub 2}) and the rice husk ash as for the comparative characterisation study. XRD analyses clearly indicated that the decomposed rice husk yielded silica of different nature which are Crystalline Rice Husk Silica (C-RHSiO{sub 2}) and Amorphous Rice Husk Silica (A-RHSiO{sub 2}). Moreover, it was found that SS-SiO{sub 2} was of Quartz phase, C-RHSiO{sub 2} was of Trydimite and Cristobalite. Through XRF detection, the highest SiO{sub 2} purity was detected in SS-SiO{sub 2} followed by C-RHSiO{sub 2} and A-RHSiO{sub 2} with purity percentages of 99.60%, 82.30% and 86.30% respectively. FTIR results clearly indicated silica (SiO{sub 2}) bonding 1056, 1064, 1047, 777, 790 and 798 cm{sup −1}) increased as the crystallinity silica increased. The Cristobalite phase was detected in C-RH SiO{sub 2} at the wavelength of 620 cm{sup −1}. Morphological features as observed by FESEM analyses confirmed that, SS-SiO{sub 2} and C-RH SiO{sub 2} showed prominent coarse granular morphology.
Purification of Industrial Phosphoric Acid using Silica Produced from Rice Husk (Part 1)

International Nuclear Information System (INIS)

Gad, H.M.H.; Awwad, N.S.; El-Khalafawy, A.; Daifullah, A.A.M.; El-Reefy, S.A.; Aly, H.F.

2008-01-01

In this work, silica was extracted from rice husk (RH) by different techniques and used for removal of some heavy metals from industrial phosphoric acid. The data obtained, showed that removal of Cu(II), Cd(II) and Pb(II) is efficient when the silica used is obtained by acidic treatment, while the removal of Fe(III) and Zn(II) is efficient when the silica used was obtained by alkaline treatment of RH. On the other hand, if silica used is obtained from rice husk ash (RHA) it was found more efficient for the removal of Mn. In all cases, the concentration of silica has been characterized by UV-Spectrophotometry. FTIR, SEM and EDX were used for predication of sorption mechanism
Reinforcement of natural rubber hybrid composites based on marble sludge/Silica and marble sludge/rice husk derived silica

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Khalil Ahmed

2014-03-01

Full Text Available A research has been carried out to develop natural rubber (NR hybrid composites reinforced with marble sludge (MS/Silica and MS/rice husk derived silica (RHS. The primary aim of this development is to scrutinize the cure characteristics, mechanical and swelling properties of such hybrid composite. The use of both industrial and agricultural waste such as marble sludge and rice husk derived silica has the primary advantage of being eco-friendly, low cost and easily available as compared to other expensive fillers. The results from this study showed that the performance of NR hybrid composites with MS/Silica and MS/RHS as fillers is extremely better in mechanical and swelling properties as compared with the case where MS used as single filler. The study suggests that the use of recently developed silica and marble sludge as industrial and agricultural waste is accomplished to provide a probable cost effective, industrially prospective, and attractive replacement to the in general purpose used fillers like china clay, calcium carbonate, and talc.
Rice Husk Ash as a Renewable Source for the Production of Value Added Silica Gel and its Application: An Overview

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Ram Prasad

2012-06-01

Full Text Available In recent years, silica gels have developed a lot of interest due to their extraordinary properties and their existing and potential applications in science and technology. Silica gel has a wide range of applications such as a desiccant, as a preservation tool to control humidity, as an adsorbent, as a catalyst and as a cata-lyst support. Silica gel is a rigid three-dimensional network of colloidal silica, and is classified as: aqua-gel, alco-gel, xero-gel and aero-gel. Out of all known solid porous materials, aero-gels are particularly known for their high specific surface area, high porosity, low bulk density, high thermal insulation value, ultra low dielectric constant and low index of refraction. Because of these extraordinary properties silica aero-gel has many commercial applications such as thermal window insulation, acoustic barriers, super-capacitors and catalytic supports. However, monolithic silica aero-gel has been used extensively in high energy physics in Cherenkov radiation detectors and in shock wave studies at high pressures, inertial confinement fusion (ICF radio-luminescent and micrometeorites. Silica gel can be prepared by using various sol gel precursors but the rice husk (RH is considered as the cheapest source for silica gel production. Rice husk is a waste product abundantly available in rice producing countries during milling of rice. This review article aims at summarizing the developments carried out so far in synthesis, properties, characterization and method of determination of silica, silica gel, silica aero-gel and silica xero-gel. The effect of synthesis parameters such as pH, temperature of burning the rice husk, acid leaching prior to formation of rice husk ash (RHA on the properties of final product are also described. The attention is also paid on the application of RH, RHA, sil-ica, silica aero-gel and silica xero-gel. Development of economically viable processes for getting rice husk silica with specific
Preparation of an efficient humidity indicating silica gel from rice ...

Indian Academy of Sciences (India)

Administrator

Department of Ceramic Engineering, National Institute of Technology, Rourkela 769 008, ... An efficient humidity indicating silica gel was prepared using rice husk ash as a raw material via ... white or colourless and shows no changes of colour.
Biocompatibility assessment of rice husk-derived biogenic silica nanoparticles for biomedical applications

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Alshatwi, Ali A., E-mail: alshatwi@ksu.edu.sa; Athinarayanan, Jegan; Periasamy, Vaiyapuri Subbarayan

2015-02-01

Synthetic forms of silica have low biocompatibility, whereas biogenic forms have myriad beneficial effects in current toxicological applications. Among the various sources of biogenic silica, rice husk is considered a valuable agricultural biomass material and a cost-effective resource that can provide biogenic silica for biomedical applications. In the present study, highly pure biogenic silica nanoparticles (bSNPs) were successfully harvested from rice husks using acid digestion under pressurized conditions at 120 °C followed by a calcination process. The obtained bSNPs were subjected to phase identification analysis using X-ray diffraction, which revealed the amorphous nature of the bSNPs. The morphologies of the bSNPs were observed using transmission electron microscopy (TEM), which revealed spherical particles 10 to 30 nm in diameter. Furthermore, the biocompatibility of the bSNPs with human lung fibroblast cells (hLFCs) was investigated using a viability assay and assessing cellular morphological changes, intracellular ROS generation, mitochondrial transmembrane potential and oxidative stress-related gene expression. Our results revealed that the bSNPs did not have any significant incompatibility in these in vitro cell-based approaches. These preliminary findings suggest that bSNPs are biocompatible, could be the best alternative to synthetic forms of silica and are applicable to food additive and biomedical applications. - Highlights: • Simple, rapid and convenient process • Amorphous and spherical with 10–30 nm size SiO{sub 2} nanoparticles were fabricated. • Biogenic silica nanoparticles showed biocompatibility. • bSNPs are an alternative to synthetic forms of silica.
The effect of nano-silica fertilizer concentration and rice hull ash doses on soybean (Glycine max (L.) Merrill) growth and yield

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Suciaty, T.; Purnomo, D.; Sakya, A. T.; Supriyadi

2018-03-01

Agriculture is facing a number of challenges included limited water supply, low nutrient use efficiency, etc affected by climate change. Nano-silica is a product of nanotechnology, the frontier technologies to enhance crop productivity under climate change threats. The purpose of the research was to investigate the effects of nano silica concentration and rice hull ash on growth and yield of soybean. The experiment was conducted at Gagasari village, Cirebon, West Java from March until June 2017. The treatments were arranged by using factorial completely randomized block design with two factors. The first factor was a concentration of nano silica fertilizer consisted of four levels i.e., 0, 1.75, 2.5, and 3.75 ml.l‑1. The second factor was doses of rice hull ash consisted of four levels i.e., 0, 1, 2, and 3 ton.ha‑1. Each treatment combinations was repeated three times. The result showed that concentration of nano silica individually affected the number of leaves and number of branches, NAR and RGR, productive branches at 21, 30-45, and 35 daps, respectively. It also affected the seed dry weight plant‑1 and plot‑1. Meanwhile, doses of rice hull ash affected LAI, NAR, and RGR, 15-30, and 30-45 dap, respectively. Dry seed weight plot‑1 was also affected by doses of rice hull ash. There was an interaction effect between nano-silica concentration and doses of rice hull ash on number pods.plant‑1. Combinations of 2.5 ml.l‑1 nano-silica and 3 ton.ha‑1 of rice hull ash gave the highest number pods.plant‑1.

Retrofit design of rice husk feeding system in the production of amorphous silica ash in a pilot scale fluidized bed combustor

International Nuclear Information System (INIS)

Abdul, A.; Rozainee, M.; Anwar, J.; Wan Alwi, R.S.

2010-01-01

Full text: Rice husk is among the most important recovery resources for silica that is produced annually in huge quantities in many countries such as Malaysia which produces 2.38 (MT) of rice paddy. Rice husks accounts for 14-35 % of the weight of the paddy harvested, depending on the paddy variety and because of its abundance it poses serious environmental problems in the rice producing countries. Therefore, the thermo-chemical conversion of rice husks to useful silica ash by fluidized bed combustion is the proven and cost-effective technology for converting the renewable waste husks by making commercial use of this rice husk ash because of its self sustaining ability. However, feeding of rice husk into the reactor bed has become a difficult problem hindering the production of amorphous silica. This is due to the poor penetration and low bulk density as well as the flaky, abrasive and joined nature of rice husk. Most of the researches into fluidized bed combustion are on laboratory or bench scale and none had discussed pilot scale combustion of rice husk into amorphous silica. A recent attempt to solve this feeding problem from an experimental investigation in a bench-scale culminates into a pilot-scale fluidized bed combustor designed with a combined screw conveyor and an inclined pneumatic feeding by direct injection, yet the problem persists. This paper presents a retrofit design of the existing 0.5 m internal diameter pilot scale fluidized bed combustor by the use of combined screw feeding system. It is envisaged that at the end of the experimental investigation the retrofit design will address the problem associated with rice husk feeding in bubbling fluidized bed combustors. (author)
Foliar application of two silica sols reduced cadmium accumulation in rice grains

International Nuclear Information System (INIS)

Liu Chuanping; Li Fangbai; Luo Chunling; Liu Xinming; Wang Shihua; Liu Tongxu; Li Xiangdong

2009-01-01

In the present study, pot experiments were conducted to investigate the effects of foliar application of two silica (Si) sols on the alleviation of cadmium (Cd) toxicity in contaminated soil to rice. Results showed that the foliar application of Si sols significantly increased the dry weight of grains (without husk) and shoots in rice grown in Cd contaminated soil, whereas the Cd concentration in the grains and shoots decreased obviously. The total accumulation of Cd in rice grains also decreased with the application of both of the Si sols, but no significant effect was found on the Cd accumulation in the shoots. For the optimal effect, Si-sol-B should be foliar applied at the tillering-stage during rice growth. The mechanism of Si foliar application to alleviate the toxicity and accumulation of Cd in grains of rice may be related to the probable Cd sequestration in the shoot cell walls
Evaluation of antioxidant potential of Brazilian rice cultivars

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Sylvio Vicentin Palombini

2013-12-01

Full Text Available This study quantified the fatty acids and evaluated the proximate composition, antioxidant activity (using the Quencher procedure, and total phenolic compound concentrations in Brazilian rice cultivars. The cultivars studied showed high amounts of unsaturated fatty acids, such as linoleic and oleic acid. The ratios of polyunsaturated and saturated fatty acids obtained were high. Regarding the antioxidant activity, the best results were found using the ABTS method and the worst in the DPPH assay. The results of the DPPH and FRAP assays showed the highest correlation. The antioxidant capacity results obtained were also much higher than those reported for other varieties worldwide. Therefore, the Quencher procedure is highly suitable for application in cereals such as rice, especially when combined with the ABTS radical capture method.
Total Arsenic, Cadmium, and Lead Determination in Brazilian Rice Samples Using ICP-MS.

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Mataveli, Lidiane Raquel Verola; Buzzo, Márcia Liane; de Arauz, Luciana Juncioni; Carvalho, Maria de Fátima Henriques; Arakaki, Edna Emy Kumagai; Matsuzaki, Richard; Tiglea, Paulo

2016-01-01

This study is aimed at investigating a suitable method for rice sample preparation as well as validating and applying the method for monitoring the concentration of total arsenic, cadmium, and lead in rice by using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Various rice sample preparation procedures were evaluated. The analytical method was validated by measuring several parameters including limit of detection (LOD), limit of quantification (LOQ), linearity, relative bias, and repeatability. Regarding the sample preparation, recoveries of spiked samples were within the acceptable range from 89.3 to 98.2% for muffle furnace, 94.2 to 103.3% for heating block, 81.0 to 115.0% for hot plate, and 92.8 to 108.2% for microwave. Validation parameters showed that the method fits for its purpose, being the total arsenic, cadmium, and lead within the Brazilian Legislation limits. The method was applied for analyzing 37 rice samples (including polished, brown, and parboiled), consumed by the Brazilian population. The total arsenic, cadmium, and lead contents were lower than the established legislative values, except for total arsenic in one brown rice sample. This study indicated the need to establish monitoring programs for emphasizing the study on this type of cereal, aiming at promoting the Public Health.
Total Arsenic, Cadmium, and Lead Determination in Brazilian Rice Samples Using ICP-MS

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Lidiane Raquel Verola Mataveli

2016-01-01

Full Text Available This study is aimed at investigating a suitable method for rice sample preparation as well as validating and applying the method for monitoring the concentration of total arsenic, cadmium, and lead in rice by using Inductively Coupled Plasma Mass Spectrometry (ICP-MS. Various rice sample preparation procedures were evaluated. The analytical method was validated by measuring several parameters including limit of detection (LOD, limit of quantification (LOQ, linearity, relative bias, and repeatability. Regarding the sample preparation, recoveries of spiked samples were within the acceptable range from 89.3 to 98.2% for muffle furnace, 94.2 to 103.3% for heating block, 81.0 to 115.0% for hot plate, and 92.8 to 108.2% for microwave. Validation parameters showed that the method fits for its purpose, being the total arsenic, cadmium, and lead within the Brazilian Legislation limits. The method was applied for analyzing 37 rice samples (including polished, brown, and parboiled, consumed by the Brazilian population. The total arsenic, cadmium, and lead contents were lower than the established legislative values, except for total arsenic in one brown rice sample. This study indicated the need to establish monitoring programs for emphasizing the study on this type of cereal, aiming at promoting the Public Health.
Preparation and Characterization of High Silica Molecular Sieve from Rice Husk

International Nuclear Information System (INIS)

Hnaung Hnaung Win; Tin Tin Aye; Kyaw Myo Naing; Nyunt Wynn

2008-03-01

A mordenite type of hight silica molecular sieve with a formula composition Na32 (ALO2)32 (SiO2)176 192H2O having a high molar ratio of SiO2 /Al2O3 (5.4) with a percent yield of 98.76% has been prepared from synthesized zeolite NaY and glycolato silicate on the basis of hydrothermal condition.Zeolicate NaY and glycolato silicate were synthesized by using 98.34% purified silica which was extracted from rice husk.The characterizations with XRD, FT-IR, EDXRF,TG-DTA and SEM techniques were studied.
Crystallization kinetic study of the lithium-disilicate bioceramic obtained from rice-husk silica starting powder

International Nuclear Information System (INIS)

Santos, F.A.; Santos, C.; Pinatti, D.G.; Davim, E.; Fernandes, M.H.F.V.

2011-01-01

In this work, the study of crystallization of the lithium disilicate glass-ceramic produced for alternative source (rice husk silica), and comparatively by commercial source (commercial silica) it was carried through. The stoichiometry 66%.mol SiO_2: 33%.mol LiO_2 was used. The kinetic studies of crystallization and calculations had been carried through thermal analysis (DTA), and were possible to study the behavior of the curves in accordance with the variation of taxes (5; 10; 15; e 20°C/min), of the granulometries 63 μm, 250μm and 1mm), and for the influence of the substitution commercial SiO_2 by rice husk. The structural characterization was carried through by X-Ray diffractometry (DRX) and scanning electron microscopy (MEV), for chemical characterization used X-Ray fluorescence (FRX). The preliminary results show that the substitution of the silica source is sufficiently promising, since the gotten properties are similar. (author)
Comparison between rice husk ash and commercial silica as filler in polymeric composites

International Nuclear Information System (INIS)

Fernandes, I.J.; Calheiro, D.; Santos, E.C.A. dos; Oliveira, R.; Rocha, T.L.A.C.; Moraes, C.A.M.

2014-01-01

The use of rice husk ash (RHA) as filler in polymeric materials has been studied in different polymers. Research reported that RHA may successfully replace silica. The silica production process using ore demands high energy input and produces considerable amounts of waste. Therefore, the replacement of silica by RHA may be economically and environmentally advantageous, reducing environmental impact and adding value to a waste material. In this context, this study characterizes and compares RHA of different sources (travelling grate reactor and fluidized bed reactor) with commercially available silicas to assess performance as filler in polymeric materials. Samples were characterized by X-ray fluorescence, loss on ignition, X-ray diffraction, grain size, specific surface area and specific weight. The results show that RHA may be used as a filler in several polymeric materials.(author)
Influence of Polyvinyl Alcohol (PVA) Addition on Silica Membrane Performance Prepared from Rice Straw

Science.gov (United States)

Wahyuningsih, S.; Ramelan, A. H.; Wardoyo, D. T.; Ichsan, S.; Kristiawan, Y. R.

2018-03-01

The utilization and modification of silica from rice straw as the main ingredient of adsorbent has been studied. The aim of this study was to determine the optimum composition of PVA (polyvinyl alcohol): silica to produce adsorbents with excellent pore characteristics, optimum adsorption efficiency and optimum pH for methyl yellow adsorptions. X-Ray Fluorescence (XRF) analysis results showed that straw ash contains 82.12 % of silica (SiO2). SAA (Surface Area Analyzer) analysis showed optimum composition ratio 5:5 of PVA: silica with surface area of 1.503 m2/g. Besides, based on the pore size distribution of PVA: silica (5:5) showed the narrow pore size distribution with the largest pore cumulative volume of 2.8 x 10-3 cc/g. The optimum pH for Methanyl Yellow adsorption is pH 2 with adsorption capacity = 72.1346%.
Effects of Silica in Rice Husk Ash (RHA) in producing High Strength Concrete

OpenAIRE

Kartini, K; Nurul Nazierah, M.Y; Zaidahtulakmal, M.Z; Siti Aisyah, G

2012-01-01

High strength concrete (HSC) are known to have a higher amount of cement binder in the mix design properties with low w/b ratio. The high mass of cement content produced substantial heat liberation in the concrete due to the reaction between cement and water, which can lead to cracking. Additive likes silica fume is too expensive to use in the HSC in order to overcome the problems, however, the initiative of utilizing the rice husk ash (RHA) which have high silica content are apply for the de...
Controlling the synthesis conditions for silica nanosphere from semi-burned rice straw

International Nuclear Information System (INIS)

Hessien, M.M.; Rashad, M.M.; Zaky, R.R.; Abdel-Aal, E.A.; El-Barawy, K.A.

2009-01-01

Silica nanoparticles have been prepared through dissolution-precipitation process from rice straw ash (RSA) for different electronic applications. The dissolution of silica from RSA was carried out using alkali leaching process by sodium hydroxide. The precipitation of silica from the produced sodium silicate solution was carried out using sulphuric acid at pH 7. The factors affecting the precipitation process of the sodium silicate solution of dissociated RSA; such as; sodium silicate concentration, sulfuric acid concentration and addition of anionic surfactant (sodium dodecyl sulfate, SDS) on the particle size of the precipitated silica were studied. X-ray diffraction (XRD), X-ray fluorescence (XRF), specific surface area S BET and transmission electron microscope (TEM) have been used for the characterization of the produced nano-silica. The results showed that the optimum conditions of the dissolution efficiency of the silica of about 99% was achieved at 100 deg. C for 4 h, and NaOH/SiO 2 molar ratio three. The particle size of the precipitated silica gel was decreased with increasing Na 2 SiO 3 and SDS concentrations, while H 2 SO 4 concentration had insignificant effect. Particle size of about 16 nm can be achieved at 30% Na 2 SiO 3 , 4% H 2 SO 4 and 200 ppm SDS. The produced silica had 99.93% purity, amorphous and nanosphere particles with narrow size distribution. The produced silica can be used in many applications especially for chemical mechanical polishing (CMP) slurries for semiconductors industries.
Genetic diversity of high performance cultivars of upland and irrigated Brazilian rice.

Science.gov (United States)

Coelho, G R C; Brondani, C; Hoffmann, L V; Valdisser, P A M R; Borba, T C O; Mendonça, J A; Rodrigues, L A; de Menezes, I P P

2017-09-21

The objective of this study was to analyze the diversity and discrimination of high-performance Brazilian rice cultivars using microsatellite markers. Twenty-nine rice cultivars belonging to EMBRAPA Arroz e Feijão germplasm bank in Brazil were genotyped by 24 SSR markers to establish their structure and genetic discrimination. It was demonstrated that the analyzed germplasm of rice presents an expressive and significant genetic diversity with low heterogeneity among the cultivars. All 29 cultivars were differentiated genetically, and were organized into two groups related to their upland and irrigated cultivation systems. These groups showed a high genetic differentiation, with greater diversity within the group that includes the cultivars for irrigated system. The genotyping data of these cultivars, with the morphological e phenotypical data, are valuable information to be used by rice breeding programs to develop new improved cultivars.
Speciation of arsenic in rice and estimation of daily intake of different arsenic species by Brazilians through rice consumption.

Science.gov (United States)

Batista, Bruno L; Souza, Juliana M O; De Souza, Samuel S; Barbosa, Fernando

2011-07-15

Rice is an important source of essential elements. However, rice may also contain toxic elements such as arsenic. Therefore, in the present study, the concentration of total arsenic and five main chemical species of arsenic (As(3+), As(5+), DMA, MMA and AsB) were evaluated in 44 different rice samples (white, parboiled white, brown, parboiled brown, parboiled organic and organic white) from different Brazilian regions using high-performance liquid chromatography hyphenated to inductively coupled plasma mass spectrometry (HPLC-ICP-MS). The mean level of total arsenic was 222.8 ng g(-1) and the daily intake of inorganic arsenic (the most toxic form) from rice consumption was estimated as 10% of the Provisional Tolerable Daily Intake (PTDI) with a daily ingestion of 88 g of rice. Inorganic arsenic (As(3+), As(5+)) and dimethylarsinic acid (DMA) are the predominant forms in all samples. The percentages of species were 38.7; 39.7; 3.7 and 17.8% for DMA, As(3+), MMA and As(5+), respectively. Moreover, rice samples harvested in the state of Rio Grande do Sul presented more fractions of inorganic arsenic than rice in Minas Gerais or Goiás, which could lead to different risks of arsenic exposure. Copyright © 2011 Elsevier B.V. All rights reserved.
The impact of wood biochar as a soil amendment in aerobic rice systems of the Brazilian Savannah

NARCIS (Netherlands)

Carvalho, M.T.M.

2015-01-01

Abstract

Keywords: tropical Savannah, biochar, soil fertility, aerobic rice, grain yield, N2O emission

Márcia Thaís de Melo Carvalho (2015). The impact of wood biochar as a soil amendment in aerobic rice systems of the Brazilian Savannah. PhD thesis,
Rice Hulls as a Renewable Complex Material Resource

Directory of Open Access Journals (Sweden)

Irina Glushankova

2018-05-01

Full Text Available As a result of rice grain processing, a big amount of waste (up to 20% is produced. It is mainly rice hulls. The main components of rice hulls are cellulose, lignin and mineral ash. The mineral ash quantity in rice hulls varies from 15 up to 20%, by weight of the rice hulls. The mineral ash consists of amorphous silica (opal-type. Due to the high content of silica in rice hulls, the material burns with difficulty under natural conditions, and it is biodegradably destroyed only with difficulty, when composted. Utilization of rice hulls then becomes an ecological problem due to huge rice production and its continuous growth. At the same time, the annual quantity of silica content in rice hulls is comparable with the quantity of amorphous silica produced as a mineral resource. The issue of manufacturing cellular glass silica construction materials from rice hulls as a renewable resource is discussed in this paper. The utilization technology is based on an amorphous silicon oxide with the use of energy from the combustion of the organic component of rice hulls.
Utilization of rice husk ash as silica source for the synthesis of mesoporous silicas and their application to CO2 adsorption through TREN/TEPA grafting

International Nuclear Information System (INIS)

Bhagiyalakshmi, Margandan; Yun, Lee Ji; Anuradha, Ramani; Jang, Hyun Tae

2010-01-01

Mesoporous MCM-41, MCM-48 and SBA-15 were synthesized using Rice husk ash (RHA) as the silica source and their defective Si-OH sites were functionalized by 3-cholropropyltrimethoxysilane (CPTMS) which was subsequently grafted with amine compounds, Tris(2-aminoethyl)amine (TREN) and Tetraethylenepentamine (TEPA). X-ray powder diffraction (XRD) and BET results of the parent mesoporous silica suggested their closeness of structural properties to those obtained from conventional silica sources. CO 2 adsorption of branched amine TREN and straight chain amine TEPA at 25, 50 and 75 deg. C was obtained by Thermogravimetric Analyser (TGA) at atmospheric pressure. TREN grafted mesoporous silica showed 7% of CO 2 adsorption while TEPA grafted mesoporous silicas showed less CO 2 adsorption, which is due to the presence of isolated amine groups in TREN. TREN grafted mesoporous silicas were also observed to be selective towards CO 2 , thermally stable and recyclable. The order of CO 2 adsorption with respect to amount of amine grafting was observed to be MCM-48/TREN > MCM-41/TREN > SBA-15/TREN.
Can rice field channels contribute to biodiversity conservation in Southern Brazilian wetlands?

Science.gov (United States)

Maltchik, Leonardo; Rolon, Ana Silvia; Stenert, Cristina; Machado, Iberê Farina; Rocha, Odete

2011-12-01

Conservation of species in agroecosystems has attracted attention. Irrigation channels can improve habitats and offer conditions for freshwater species conservation. Two questions from biodiversity conservation point of view are: 1) Can the irrigated channels maintain a rich diversity of macrophytes, macroinvertebrates and amphibians over the cultivation cycle? 2) Do richness, abundance and composition of aquatic species change over the rice cultivation cycle? For this, a set of four rice field channels was randomly selected in Southern Brazilian wetlands. In each channel, six sample collection events were carried out over the rice cultivation cycle (June 2005 to June 2006). A total of 160 taxa were identified in irrigated channels, including 59 macrophyte species, 91 taxa of macroinvertebrate and 10 amphibian species. The richness and abundance of macrophytes, macroinvertebrates and amphibians did not change significantly over the rice cultivation cycle. However, the species composition of these groups in the irrigation channels varied between uncultivated and cultivated periods. Our results showed that the species diversity found in the irrigation channels, together with the permanence of water enables these man-made aquatic networks to function as important systems that can contribute to the conservation of biodiversity in regions where the wetlands were converted into rice fields. The conservation of the species in agriculture, such as rice field channels, may be an important alternative for biodiversity conservation in Southern Brazil, where more than 90% of wetland systems have already been lost and the remaining ones are still at high risk due to the expansion of rice production.
Determination of genetic variability of traditional varieties of Brazilian rice using microsatellite markers

Directory of Open Access Journals (Sweden)

Claudio Brondani

2006-01-01

Full Text Available The rice (Oryza sativa breeding program of the Rice and Bean research center of the Brazilian agricultural company Empresa Brasileira de Pesquisa Agropecuária (Embrapa is well established and provides new cultivars every year to attend the demand for improved high yielding varieties with tolerance to biotic and abiotic stresses. However, the elite genitors used to compose new populations for selection are closely related, contributing to the yield plateau reached in the last 20 years. To overcome this limit, it is necessary to broaden the genetic basis of the cultivars using diverse germplasm such as wild relatives or traditional varieties, with the latter being more practical because they are more easily crossed with elite germplasm to accelerate the recovery of modern plant types in the breeding lines. The objective of our study was to characterize the allelic diversity of 192 traditional varieties of Brazilian rice using 12 simple sequence repeat (SSR or microsatellite markers. The germplasm was divided into 39 groups by common name similarity. A total of 176 alleles were detected, 30 of which (from 23 accessions were exclusive. The number of alleles per marker ranged from 6 to 22, with an average of 14.6 alleles per locus. We identified 16 accessions as a mixture of pure lines or heterozygous plants. Dendrogram analysis identified six clusters of identical accessions with different common names and just one cluster with identical accessions with the same common name, indicating that SSR markers are fundamental to determining the genetic relationship between landraces. A subset of 24 landraces, representatives of the 13 similarity groups plus the 11 accessions not grouped, was the most variable set of genotypes analyzed. These accessions can be used as genitors to increase the genetic variability available to rice breeding programs.
Occurrence of Aspergillus section Flavi and aflatoxins in Brazilian rice: From field to market.

Science.gov (United States)

Katsurayama, Aline M; Martins, Ligia M; Iamanaka, Beatriz T; Fungaro, Maria Helena P; Silva, Josué J; Frisvad, Jens C; Pitt, John I; Taniwaki, Marta H

2018-02-02

The guarantee of the high quality of rice is of utmost importance because any toxic contaminant may affect consumer health, especially in countries such as Brazil where rice is part of the daily diet. A total of 187 rice samples, from field, processing and market from two different production systems, wetland from the state of Rio Grande do Sul, dryland, from the state of Maranhão and market samples from the state of São Paulo, were analyzed for fungi belonging to Aspergillus section Flavi and the presence of aflatoxins. Twenty-three soil samples from wetland and dryland were also analyzed. A total of 383 Aspergillus section Flavi strains were isolated from rice and soil samples. Using a polyphasic approach, with phenotypic (morphology and extrolite profiles) and molecular data (beta-tubulin gene sequences), five species were identified: A. flavus, A. caelatus, A. novoparasiticus, A. arachidicola and A. pseudocaelatus. This is the first report of these last three species from rice and rice plantation soil. Only seven (17%) of the A. flavus isolates produced type B aflatoxins, but 95% produced kojic acid and 69% cyclopiazonic acid. Less than 14% of the rice samples were contaminated with aflatoxins, but two of the market samples were well above the maximum tolerable limit (5μg/kg), established by the Brazilian National Health Surveillance Agency. Copyright © 2017 Elsevier B.V. All rights reserved.
Comparison between rice husk ash and commercial silica as filler in polymeric composites; Comparacao de cinza de casca de arroz e silica comercial como carga em compositos polimericos

Energy Technology Data Exchange (ETDEWEB)

Fernandes, I.J.; Calheiro, D.; Santos, E.C.A. dos; Oliveira, R.; Rocha, T.L.A.C.; Moraes, C.A.M., E-mail: ijk.fernandes@gmail.com [Universidade do Vale do Rio dos Sinos (UNISINOS), Sao Leopoldo, RS (Brazil). Pos-Graduacao em Engenharia Civil

2014-07-01

The use of rice husk ash (RHA) as filler in polymeric materials has been studied in different polymers. Research reported that RHA may successfully replace silica. The silica production process using ore demands high energy input and produces considerable amounts of waste. Therefore, the replacement of silica by RHA may be economically and environmentally advantageous, reducing environmental impact and adding value to a waste material. In this context, this study characterizes and compares RHA of different sources (travelling grate reactor and fluidized bed reactor) with commercially available silicas to assess performance as filler in polymeric materials. Samples were characterized by X-ray fluorescence, loss on ignition, X-ray diffraction, grain size, specific surface area and specific weight. The results show that RHA may be used as a filler in several polymeric materials.(author)

Crystallization kinetic study of the lithium-disilicate bioceramic obtained from rice-husk silica starting powder; Estudo cinetico da cristalizacao da bioceramica de dissilicato de litio obtida atraves da silica da casca de arroz

Energy Technology Data Exchange (ETDEWEB)

Santos, F.A.; Santos, C.; Pinatti, D.G., E-mail: elipeantunes@usp.br [Universidade de Sao Paulo (EEL/USP), Lorena, SP (Brazil). Escola de Engenharia; Lazar, D.R.R. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Davim, E.; Fernandes, M.H.F.V. [Universidade de Aveiro, Campos Universitario de Santiago, Aveiro (Portugal)

2011-07-01

In this work, the study of crystallization of the lithium disilicate glass-ceramic produced for alternative source (rice husk silica), and comparatively by commercial source (commercial silica) it was carried through. The stoichiometry 66%.mol SiO{sub 2}: 33%.mol LiO{sub 2} was used. The kinetic studies of crystallization and calculations had been carried through thermal analysis (DTA), and were possible to study the behavior of the curves in accordance with the variation of taxes (5; 10; 15; e 20°C/min), of the granulometries 63 μm, 250μm and 1mm), and for the influence of the substitution commercial SiO{sub 2} by rice husk. The structural characterization was carried through by X-Ray diffractometry (DRX) and scanning electron microscopy (MEV), for chemical characterization used X-Ray fluorescence (FRX). The preliminary results show that the substitution of the silica source is sufficiently promising, since the gotten properties are similar. (author)
Determination of trace elements in Brazilian rice grains and in biological reference materials by neutron activation analysis

International Nuclear Information System (INIS)

Maihara, V.A.; Vasconcellos, M.B.A.

1989-01-01

Instrumental neutron activation analysis was applied to the determination of the elements Na, K, Br, As, Rb, Zn, Co, Fe and Sc in Brazilian rice samples and in biological standards. Hg and Se concentrations were determined by using a simple radiochemical separation. The chemical procedure was carried out by means of distillation of Hg and Se in HBr medium and subsequent precipitation of selenium by sodium methabissulfide and mercury by thioacetamide. The accuracy of the instrumental and radiochemical methods was evaluated by means of analysis of the Reference Materials NBS-Bovine Liver, Bowen's Kale and NBS-Rice Flour. (author) [pt
Determination of trace elements in Brazilian rice grains and in biological reference materials by neutron activation analysis

International Nuclear Information System (INIS)

Maihara, V.A.; Vasconcellos, M.B.A.

1989-01-01

INAA was applied to the determination of the elements Na, K, Br, As, Rb, Zn, Co, Fe and Sc in Brazilian rice samples and in biological standards. Hg and Se concentrations were determined using a simple radiochemical separation. The chemical procedure was carried out by means of distillation of Hg and Se in HBr medium and subsequent precipitation of Se by sodium metabisulfite and Hg by thioacetamide. The accuracy of the instrumental and radiochemical methods was evaluated by means of analysis of the Reference Materials NBS-Bovine Liver, Bowen's Kale and NBS-Rice Flour. (author) 15 refs.; 5 tabs
Pozzolanic Reactivity of Silica Fume and Ground Rice Husk Ash as Reactive Silica in a Cementitious System: A Comparative Study

Directory of Open Access Journals (Sweden)

Weiting Xu

2016-03-01

Full Text Available This study comparably assessed the pozzolanic effect of silica fume (SF and ground rice husk ash (RHA as supplementary cementing materials on the properties of blended cement pastes and concretes. A commonly commercial silica fume (SF and locally-produced rice husk ash (RHA samples with two finenesses (one with larger size than cement and the other with smaller size than cement were used in this study. Material properties of SF and RHA were experimentally characterized. Hydration and mechanical properties of cement pastes incorporating SF and RHA were determined by thermogravimetric analysis (TGA and compressive strength tests, respectively. Properties of concretes regarding workability, mechanical property, durability, and microstructure were evaluated. Results showed that, although the finely ground RHA used in this study possessed lower SiO2 content and higher particle size compared to SF, it exhibited comparable pozzolanic reactivity with SF due to the nano-scale pores on its each single particle, leading to a higher specific surface area. The optimal replacement levels of SF and RHA were 10% by weight of cement in pastes and concretes. Although addition of SF and RHA led to a significant reduction in slump for the fresh mixtures, inclusion of up to 30% of SF or 15% of ground RHA did not adversely affect the strength of concretes. At the same mix, incorporation of finely-ground RHA in cement composites provided comparable mechanical properties, hydration degree, and durability with SF blended cement composites, owing to the porous structure and high specific surface area of RHA particles. Microstructure morphology analysis of concretes explored by scanning electron microscopy (SEM further validated the strength and the durability test results.
Synthesis of biogenic silicon/silica (Si/SiO2) nanocomposites from rice husks and wheat bran through various microorganisms

Science.gov (United States)

Kaur, Taranjot; Pal Singh, Gurwinder; Kaur, Gurneet; Kaur, Sukhvir; Gill, Prabhjot Kaur

2016-08-01

Biosilification is an economically viable, energy saving and green approach for the commercial scale synthesis of oxide nanomaterials. The room temperature synthesis of oxide nanocomposites from cost effective agro-based waste is a particular example of biosilification. In this study, synthesis of Si/SiO2 nanocomposites from inexpensive agro-based waste material i.e. rice husks (RH) and wheat bran (WB) has been carried out by means of various eukaryotic microorganisms, i.e. Actinomycete, Fusarium oxysporum, Aspergillus niger, Trichoderma sp. and Penicillium sp., under ambient conditions. The XRD diffrectrograms represents that the synthesized nanomaterials exhibits silicon, amorphous silica and other crystal arrays such as cristobalite, trydimite and quartz, depending upon the type microorganism and time period used for extraction. All of the aforesaid microorganism bio transformed the naturally occurring amorphous silica to crystalline structures within the period of 24 h. However, the Actinomycete and Trichoderma sp. took 48 h in case of rice husks for biotransformation of naturally occurring plant silica to crystalline nanocomposite. While in case of wheat bran, Actinomycete and Trichoderma sp. took 24 h for biotransformation. The extracted nanocomposites exhibits band edge in the range 230-250 nm and blue emission. The procedure described in study can be used for commercial level production of Si/SiO2 nanocomposites from agro based waste materials.
Fabrication of mesoporous silica nanoparticles by sol gel method followed various hydrothermal temperature

Science.gov (United States)

Purwaningsih, Hariyati; Pratiwi, Vania Mitha; Purwana, Siti Annisa Bani; Nurdiansyah, Haniffudin; Rahmawati, Yenny; Susanti, Diah

2018-04-01

Rice husk is an agricultural waste that is potentially used as natural silica resources. Natural silica claimed to be safe in handling, cheap and can be generate from cheap resource. In this study mesoporous silica was synthesized using sodium silicate extracted from rice husk ash. This research's aim are to study the optimization of silica extraction from rice husk, characterizing mesoporous silica from sol-gel method and surfactant templating from rice husk and the effect of hydrothermal temperature on mesoporous silica nanoparticle (MSNp) formation. In this research, rice husk was extracted with sol-gel method and was followed by hydrothermal treatment; several of hydrothermal temperatures were 85°C, 100°C, 115°C, 130°C and 145° for 24 hours. X-ray diffraction analysis was identified of α-SiO2 phase and NaCl compound impurities. Scherer's analysis method for crystallite size have resulted 6.27-40.3 nm. FTIR results of silica from extraction and MSNp indicated Si-O-Si bonds on the sample. SEM result showed the morphology of the sample that has spherical shape and smooth surface. TEM result showed particle size ranged between 69,69-84,42 nm. BET showed that the pore size classified as mesoporous with pore diameter size is 19,29 nm.
Potassium hydroxide pulping of rice straw in biorefinery initiatives.

Science.gov (United States)

Jahan, M Sarwar; Haris, Fahmida; Rahman, M Mostafizur; Samaddar, Purabi Rani; Sutradhar, Shrikanta

2016-11-01

Rice straw is supposed to be one of the most important lignocellulosic raw materials for pulp mill in Asian countries. The major problem in rice straw pulping is silica. The present research is focused on the separation of silica from the black liquor of rice straw pulping by potassium hydroxide (KOH) and pulp evaluation. Optimum KOH pulping conditions of rice straw were alkali charge 12% as NaOH, cooking temperature 150°C for 2h and material to liquor ratio, 1:6. At this condition pulp yield was 42.4% with kappa number 10.3. KOH pulp bleached to 85% brightness by D0EpD1 bleaching sequences with ClO2 consumption of 25kg/ton of pulp. Silica and lignin were separated from the black liquor of KOH pulping. The amount of recovered silica, lignin and hemicelluloses were 10.4%, 8.4% and 13.0%. The papermaking properties of KOH pulp from rice straw were slightly better than those of corresponding NaOH pulp. Copyright © 2016 Elsevier Ltd. All rights reserved.
Biochar improves fertility of a clay soil in the Brazilian Savannah: short term effects and impact on rice yield

NARCIS (Netherlands)

Melo Carvalho, de M.T.; Madari, B.E.; Bastiaans, L.; Oort, van P.A.J.; Heinemann, A.B.; Silva, da M.A.S.; Maia, A.H.N.; Meinke, H.B.

2013-01-01

The objective of this study was to report single season effects of wood biochar (char) application coupled with N fertilization on soil chemical properties, aerobic rice growth and grain yield in a clayey Rhodic Ferralsol in the Brazilian Savannah. Char application effected an increase in soil pH,
removal of heavy metal ions from aqueous solution using rice husks

African Journals Online (AJOL)

User

extraction (Rohaizer et al. 2013). ... activated carbon, zeolites, clays and mesoporous silicas ... Extraction of Silica from Rice Husks Ash. Rice husks ... for 16 hours after which the solid materials .... liquid phase and adsorbed phase, based on.
Characterization of Polycaprolactone and Rice Husk Silica Composite (PCL-SiO2) by E-Spinning to Apply Supporter for Drug Release

Science.gov (United States)

Song, Sinae; Hilonga, Askwar; Taik Kim, Hee

2018-03-01

Polycaprolactone (PCL) is an interesting material to apply biomedical field owing to its biodegradability and biocompatibility which is suitable for a specific site with longer healing times. Blending the polymer with other materials has degradation property improved with the effective and economic method. This study was conducted to fabricate supporter based on Polycaprolactone and Rice husk silica (PCL-SiO2) by using electrospinning. Nano-porous silica in the composite was synthesized from rice husk having properties of economic, eco-friendly and high surface area. It drew to enhance the amount of drug loading in the carrier. Electrospinning technique is used to fabricate fibrous component by optimization condition obtained from previous mechanical properties experiments. Release experiment was carried out by the degree of dye absorbance at 544nm by ultraviolet–visible spectroscopy, the RhB in SiO2 alternative drug for modelling of drug release was released for 1 ~ 20 days at 37°C in phosphate buffer. Furthermore, the Mechanical property was confirmed by DSC, TGA. Morphology and degree of biodegradation were shown as SEM images and EDS.
Recycling rice husks for high-capacity lithium battery anodes.

Science.gov (United States)

Jung, Dae Soo; Ryou, Myung-Hyun; Sung, Yong Joo; Park, Seung Bin; Choi, Jang Wook

2013-07-23

The rice husk is the outer covering of a rice kernel and protects the inner ingredients from external attack by insects and bacteria. To perform this function while ventilating air and moisture, rice plants have developed unique nanoporous silica layers in their husks through years of natural evolution. Despite the massive amount of annual production near 10(8) tons worldwide, so far rice husks have been recycled only for low-value agricultural items. In an effort to recycle rice husks for high-value applications, we convert the silica to silicon and use it for high-capacity lithium battery anodes. Taking advantage of the interconnected nanoporous structure naturally existing in rice husks, the converted silicon exhibits excellent electrochemical performance as a lithium battery anode, suggesting that rice husks can be a massive resource for use in high-capacity lithium battery negative electrodes.
Phase identification of SiO/sub/2 in rice husk ash

International Nuclear Information System (INIS)

Ikram, N.; Hussain, K.; Shah, M.A.

1987-01-01

Semiconductor grade silicon is generally used in the manufacture of highly efficient solar cells. In this paper, we describe rice husk ash (RHA) as a viable raw material for obtaining silica. Rice husk contains about 15 percent silica. Rice husk ash is prepared by first burning rice husk in air at a temperature of 300 degree centigrade and then firing it in alumina crucibles in a muffle furnace upto 1200 degree centigrade. Rice husk ash is then ground into fine powder and its X-ray diffraction pattern is obtained in order to studies its structure at various temperatures of preparation. (author/A.B)
Effect of Nano Silica on the Physical Property of Porous Concrete Pavement

Science.gov (United States)

Yusak, Mohd Ibrahim Mohd; Ezree Abdullah, Mohd; Putra Jaya, Ramadhansyah; Rosli Hainin, Mohd; Ibrahim, Mohd Haziman Wan

2017-08-01

Rice husk can be categorized as an organic waste material from paddy industries. Silica is a major inorganic element of the rice husk. The aim of present study is to evaluate the effect of Nano silica on the physical properties of porous concrete pavement. Rice husk has been burned in the furnace (650°C for 6 hours) and ground for four different grinding times (33, 48, 63 and 81 hours). Five types of mixes were prepared to evaluate the different Nano silica grinding time. A Nano silica dosage of 10% by weight of binder was used throughout the experiments. The physical properties were examined through compressive strength, transmission electron microscopy and x-ray fluorescence. The experimental results indicate that the different Nano size gives a different effect to porous concrete strength. Based on the results obtained, Nano silica ground for 63 hours (65.84nm) gives the best result and performance to porous concrete pavement specimens.
Impacts of soil incorporation of pre-incubated silica-rich rice residue on soil biogeochemistry and greenhouse gas fluxes under flooding and drying.

Science.gov (United States)

Gutekunst, Madison Y; Vargas, Rodrigo; Seyfferth, Angelia L

2017-09-01

Incorporation of silica-rich rice husk residue into flooded paddy soil decreases arsenic uptake by rice. However, the impact of this practice on soil greenhouse gas (GHG) emissions and elemental cycling is unresolved particularly as amended soils experience recurrent flooding and drying cycles. We evaluated the impact of pre-incubated silica-rich rice residue incorporation to soils on pore water chemistry and soil GHG fluxes (i.e., CO 2 , CH 4 , N 2 O) over a flooding and drying cycle typical of flooded rice cultivation. Soils pre-incubated with rice husk had 4-fold higher pore water Si than control and 2-fold higher than soils pre-incubated with rice straw, whereas the pore water As and Fe concentrations in soils amended with pre-incubated straw and husk were unexpectedly similar (maximum ~0.85μM and ~450μM levels, respectively). Pre-incubation of residues did not affect Si but did affect the pore water levels of As and Fe compared to previous studies using fresh residues where straw amended soils had higher As and Fe in pore water. The global warming potential (GWP) of soil GHG emissions decreased in the order straw (612±76g CO 2 -eqm -2 )>husk (367±42gCO 2 -eqm -2 )>ashed husk=ashed straw (251±26 and 278±28gCO 2 -eqm -2 )>control (186±23gCO 2 -eqm -2 ). The GWP increase due to pre-incubated straw amendment was due to: a) larger N 2 O fluxes during re-flooding; b) smaller contributions from larger CH 4 fluxes during flooded periods; and c) higher CH 4 and CO 2 fluxes at the onset of drainage. In contrast, the GWP of the husk amendment was dominated by CO 2 and CH 4 emissions during flooded and drainage periods, while ashed amendments increased CO 2 emissions particularly during drainage. This experiment shows that ashed residues and husk addition minimizes GWP of flooded soils and enhances pore water Si compared to straw addition even after pre-incubation. Copyright © 2017 Elsevier B.V. All rights reserved.
Preparation of Silicon by Calcium Reduction of Purified Rice Husk Ash

International Nuclear Information System (INIS)

Swe Zin Tun

2011-12-01

This research has studied on the possibility of production and preparation of silicon powder from rice husk ash (RHA) as raw material. RHA from gasifier, a waste product of the rice mill is rich in silica which contains 90.43% of silica. RHAs were purified by precipitation method using 1.5N, 2N, 2.5N and 3N of sodium hydroxide solution and 4.5N, 5N, 5.5N and 6.5N of sulphuric acid solution. The highest yield percent of silica was given by using 2.5N sodium hydroxide solution and 5N sulphuric acid solution X-ray fluoresence (XRF), X-rays diffraction (HRD) and Fourier transform infrared (FTRI) spectra were applied for determination of mineral content and chemical bonding in extracted silica and rice husk ash. Metallothermic reduction of purified extracted silica with calcium was investigated within the temperacture range of 700-900 C. The reduction product was characterized by XRD, XRF and scanning electron microcopy (SEM). The effect of temperature and reaction time in which reduction process was studied in this research.
UTILIZATION OF RICE HUSK AS RAW MATERIAL IN SYNTHESIS OF MESOPOROUS SILICATES MCM-41

Directory of Open Access Journals (Sweden)

Suyanta Suyanta

2011-12-01

Full Text Available The research about synthesis and characterization of MCM-41 from rice husk has been done. Silica (SiO2 was extracted from rice husk by refluxing with 3M hydrochloric solution at 80 °C for 3 h. The acid-leached rice husk was filtered, washed, dried and calcined at 650 °C for 6 h lead the rough powder of rice husk silica with light brown in color. Characterization was carried out by X-ray diffraction (XRD and FTIR spectroscopy method. Rice husk silica was dissolved into the sodium hydroxide solution leading to the solution of sodium silicate, and used as silica source for the synthesis of MCM-41. MCM-41 was synthesized by hydrothermal process to the mixture prepared from 29 g of distilled water, 8.67 g of cetyltrimethyl ammonium bromide (CTMAB, 9.31 g of sodium silicate solution, and amount mL of 1 M H2SO4. Hydrothermal process was carried out at 100 °C in a teflon-lined stainless steel autoclave heated in the oven for 36 h. The solid phase was filtered, then washed with deionised water, and dried in the oven at 100 °C for 2 h. The surfactant CTMAB was removed by calcination at 550 °C for 10 h with heating rate 2 °C/min. The as-synthesized and calcined crystals were characterized by using FTIR spectroscopy, X-ray diffraction and N2 physisorption methods. In order to investigate the effect of silica source, the same procedure was carried out by using pure sodium silicate as silica source. It was concluded that silica extracted from rice husk can be used as raw materials in the synthesis of MCM-41, there is no significant difference in crystallinity and pore properties when was compared to material produced from commercial sodium silicate.
Preparation and characterization of electron-beam treated HDPE composites reinforced with rice husk ash and Brazilian clay

Energy Technology Data Exchange (ETDEWEB)

Ortiz, A.V., E-mail: angelortiz@ipen.br [Nuclear and Energy Research Institute, IPEN-CNEN/SP Av. Prof. Lineu Prestes 2242, São Paulo, SP 05508-000 (Brazil); Teixeira, J.G.; Gomes, M.G.; Oliveira, R.R. [Nuclear and Energy Research Institute, IPEN-CNEN/SP Av. Prof. Lineu Prestes 2242, São Paulo, SP 05508-000 (Brazil); Díaz, F.R.V. [Metallurgical and Materials Engineering Department, Polytechnic School, University of São Paulo Av. Prof. Mello de Morais 2463, São Paulo, SP 05508-900 (Brazil); Moura, E.A.B. [Nuclear and Energy Research Institute, IPEN-CNEN/SP Av. Prof. Lineu Prestes 2242, São Paulo, SP 05508-000 (Brazil)

2014-08-15

Highlights: • We examine changes in HDPE properties when waste and clay are used as reinforcement. • The addition of only 3% of clay leads to important gains in HDPE properties. • The use of electron-beam contributes to greater improvements in material properties. • We observe 85% of cross-linking degree for the HDPE when treated with e-beam. - Abstract: This work evaluates the morphology, mechanical and thermo-mechanical properties of high density polyethylene (HDPE) composites. HDPE reinforced with rice husk ashes (80:20 wt%), HDPE reinforced with clay (97:3 wt%) and HDPE reinforced with both rice husk ashes and clay(77:20:3 wt%) were obtained. The Brazilian bentonite chocolate clay was used in this study. This Brazilian smectitic clay is commonly used to produce nanocomposites. The composites were produced by melting extrusion process and then irradiation was carried out in a 1.5 MeV electron-beam accelerator (room temperature, presence of air). Comparisons using the irradiated and non-irradiated neat polymer, and the irradiated and non-irradiated composites were made. The materials obtained were submitted to tensile, flexural and impact tests. Additionally HDT, SEM and XRD analyses were carried out along with the sol–gel analysis which aimed to assess the cross-linking degree of the irradiated materials. Results showed great improvement in most HDPE properties and a high cross-linking degree of 85% as a result of electron-beam irradiation of the material.
Isolation and characterization of pulp from sugarcane bagasse and rice straw

International Nuclear Information System (INIS)

Saiful Azhari, S.; Suhardy, D.; Kasim, F.H; Nazry Saleh, M.

2007-01-01

The amount of sugarcane bagasse and rice straw in the state of Perlis (Malaysia) is abundant while its utilization is still limited. One of the alternatives for the bagasse and straw utilization is as pulp raw material. This paper reviews on pulp from sugarcane bagasse and rice straw and its suitability for paper production. In this study, the pulp was extracted by the Soxhlet extraction method. The objective of this study was to investigate the cellulose, lignin and silica content of the pulp from sugarcane bagasse and rice straw. For rice straw, the presence of large amount of pentosanes in the pulp and black liquors, which also contain silica were decreased the using of straw in the paper industry. Therefore, formic acid pulping and NaOH treatment are studied to reduce or prevent silica. The isolated pulp samples were further characterized by Scanning Electron Microscope (SEM) to investigate their fiber dimensions. (Author)
Studies on development of new functional natural materials from agricultural products - Technology developments for ceramic powders and materials from rice phytoliths

Energy Technology Data Exchange (ETDEWEB)

Kang, Dae Kap; Kim, Yong Ik [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of); Yoon, Nang Kyu; Seong, Seo Yong [Myongseong Ceramics Com., Taejon (Korea, Republic of); Ryu, Sang Eun [Bae Jae Univ., Taejon (Korea, Republic of); Lee, Jae Chun [Myungji Univ., Seoul (Korea, Republic of)

1995-08-01

Based on an estimation of annual rice production of 5.2 million tons, rice husks by-production reaches to 1.17 million tons per year in Korea. Distinguished to other corns, rice contains a lot of Si; 10-20% by weight in rice husks calculated as silica. The aim of this research project is to develop technologies for ceramic powders and materials utilizing the silica in rice husks called phytoliths. In this first year research, researches of the following subjects were performed; material properties of rice husks, milling of rice husks, acid treatments, oxidations at low and high temperatures, sintering and crystalization of amorphous silica, low temperature carburization, formation of silicon carbide whiskers, and brick lightening method using milled rice husks. 11 tabs., 49 figs., 75 refs. (Author).
Adsorption of Pb(II) using silica gel composite from rice husk ash modified 3-aminopropyltriethoxysilane (APTES)-activated carbon from coconut shell

Science.gov (United States)

Yusmaniar, Purwanto, Agung; Putri, Elfriyana Awalita; Rosyidah, Dzakiyyatur

2017-03-01

Silica gel modified by 3-aminopropyltriethoxysilane (APTES) was synthesized from rice husk ash combined with activated carbon from coconut shell yielded the composite adsorbent. The composite was characterized by Fourier Transform Infra Red spectroscopy (FT-IR), Electron Dispersive X-Ray (EDX), Surface Area Analyzer (SAA) and adsorption test by Atomic Absorption Spectrometry (AAS). This composite adsorbent has been used moderately for the removal of lead ions from metal solutions and compared with silica gel modified APTES and activated carbon. The adsorption experiments of Pb -ions by adsorbents were performed at different pH and contact time with the same metal solutions concentration, volume solution, and adsorbent dosage. The optimum pH for the adsorption was found to be 5.0 and the equilibrium was achieved for Pb with 20 min of contact time. Pb ions adsorption by composite silica gel modified APTES-activated carbon followed by Langmuir isotherm model with qmax value of 46.9483 mg/g that proved an adsorbent mechanism consistent to the mechanism of monolayer formation.

Using rice straw to manufacture ceramic bricks

Directory of Open Access Journals (Sweden)

Gorbunov German Ivanovich

2014-12-01

Full Text Available In the article, the co-authors offer their advanced and efficient methodologies for the recycling of the rice straw, as well as the novel approaches to the ceramic brick quality improvement through the application of the rice straw as the combustible additive and through the formation of amorphous silica in the course of the rice straw combustion. The co-authors provide characteristics of the raw materials, production techniques used to manufacture ceramic bricks, and their basic properties in the article. The co-authors describe the simulated process of formation of amorphous silica. The process in question has two independent steps (or options: 1 rice straw combustion and ash formation outside the oven (in the oxidizing medium, and further application of ash as the additive in the process of burning clay mixtures; 2 adding pre-treated rice straw as the combustible additive into the clay mixture, and its further burning in compliance with the pre-set temperature mode. The findings have proven that the most rational pre-requisite of the rice straw application in the manufacturing of ceramic bricks consists in feeding milled straw into the clay mixture to be followed by molding, drying and burning. Brick samples are highly porous, and they also demonstrate sufficient compressive strength. The co-authors have also identified optimal values of rice straw and ash content in the mixtures under research.
Catalytic performance of organically templated nano nickel incorporated-rice husk silica in hydroconversion of cyclohexene and dehydrogenation of ethanol

Directory of Open Access Journals (Sweden)

Salah A. Hassan

2013-06-01

Full Text Available Rice husk silica (RHS was extracted from local rice husk by acid digestion and burning at 650 °C. RHS-Ni catalyst was prepared by dissolving RHS in 1 N NaOH and titrating with 3 N HNO3 containing 10 wt.% Ni2+. The organic modifiers, either p-amino benzoic acid (A or p-phenylenediamine (PDA were incorporated in 5 wt.% and reduced in H2 flow. Investigation of the three catalysts, (RHS-NiR350, (RHS-Ni–AR350 and (RHS-Ni–PDAR350, confirmed good dispersion of Ni nanoparticles; all catalysts were amorphous. The BET surface areas increased in the order: (RHS-NiR350 150 °C, the backward dehydrogenation pathway was more favored, due to unavailability of H2; the process became structure-sensitive. In ethanol conversion, the prevailing dehydrogenation activity of organically modified catalyst samples was encouraged by improved homogeneous distribution of Ni nanoparticles and created micropre system.
Processing Methods of Alkaline Hydrolysate from Rice Husk

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Olga D. Arefieva

2017-07-01

Full Text Available This paper devoted to finding processing methods of alkaline hydrolysate produced from rice husk pre-extraction, and discusses alkaline hydrolysate processing schemed and disengagement of some products: amorphous silica of various quality, alkaline lignin, and water and alkaline extraction polysaccharides. Silica samples were characterized: crude (air-dried, burnt (no preliminary water treatment, washed in distilled water, and washed in distilled water and burnt. Waste water parameters upon the extraction of solids from alkaline hydrolysate dropped a few dozens or thousand times depending on the applied processing method. Color decreased a few thousand times, turbidity was virtually eliminated, chemical oxygen demanded about 20–136 times; polyphenols content might decrease 50% or be virtually eliminated. The most prospective scheme obtained the two following solid products from rice husk alkaline hydrolysate: amorphous silica and alkaline extraction polysaccharide. Chemical oxygen demand of the remaining waste water decreased about 140 times compared to the silica-free solution.
Ultrastructural characterization of rice husk submitted to different pretreatments to optimize its fermentation

Energy Technology Data Exchange (ETDEWEB)

Lhoneux, B de; Gerlache, L; Clemente, A; Roda-Santos, M L; Menaia, J A.G.; Fernandes, T H

1988-01-01

Silica distribution in rice husk was examined by scanning electron microscopy. Silica appeared as a solid structure in the outer epidermis and as a dispersed system inside the husk. Pretreatments (steam autoclaving, water autoclaving, alkaline leaching, gamma irradiation, and ultra sound) were applied in order to achieve an improvement in rice husk digestibility. Alkaline leaching removed a significant part of the silica structure, therefore allowing a larger area of exposure of the cell wall polymers to the degrading enzymes. Among the pretreatments, alkaline leaching appeared to be the most useful, while others seemed not to be very successful in attaining the desired effect.
Rice straw as a feedstock for biofuels: Availability, recalcitrance, and chemical properties: Rice straw as a feedstock for biofuels

Energy Technology Data Exchange (ETDEWEB)

Satlewal, Alok [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Chemical and Biomolecular Engineering; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Joint Inst. for Biological Sciences, Biosciences Division; Indian Oil Corporation Ltd, Faridabad (India), Dept. of Bioenergy, DBT-IOC Centre for Advanced Bioenergy Research, Research and Development Centre; Agrawal, Ruchi [Indian Oil Corporation Ltd, Faridabad (India), Dept. of Bioenergy, DBT-IOC Centre for Advanced Bioenergy Research, Research and Development Centre; Bhagia, Samarthya [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Chemical and Biomolecular Engineering; Das, Parthapratim [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Chemical and Biomolecular Engineering; Ragauskas, Arthur J. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Chemical and Biomolecular Engineering

2017-10-17

The surplus availability of rice straw, its limited usage and environment pollution caused by inefficient burning has fostered research for its valorization to biofuels. This review elucidates the current status of rice straw potential around the globe along with recent advances in revealing the critical factors responsible for its recalcitrance and chemical properties. The role and accumulation of high silica content in rice straw has been elucidated with its impact on enzymatic hydrolysis in a biorefinery environment. The correlation of different pretreatment approaches in modifying the physiochemical properties of rice straw and improving the enzymatic accessibility has also been discussed. This study highlights new challenges, resolutions and opportunities for rice straw based biorefineries.
Preparation of porous bio-char and activated carbon from rice husk by leaching ash and chemical activation.

Science.gov (United States)

Ahiduzzaman, Md; Sadrul Islam, A K M

2016-01-01

Preparation porous bio-char and activated carbon from rice husk char study has been conducted in this study. Rice husk char contains high amount silica that retards the porousness of bio-char. Porousness of rice husk char could be enhanced by removing the silica from char and applying heat at high temperature. Furthermore, the char is activated by using chemical activation under high temperature. In this study no inert media is used. The study is conducted at low oxygen environment by applying biomass for consuming oxygen inside reactor and double crucible method (one crucible inside another) is applied to prevent intrusion of oxygen into the char. The study results shows that porous carbon is prepared successfully without using any inert media. The adsorption capacity of material increased due to removal of silica and due to the activation with zinc chloride compared to using raw rice husk char. The surface area of porous carbon and activated carbon are found to be 28, 331 and 645 m(2) g(-1) for raw rice husk char, silica removed rice husk char and zinc chloride activated rice husk char, respectively. It is concluded from this study that porous bio-char and activated carbon could be prepared in normal environmental conditions instead of inert media. This study shows a method and possibility of activated carbon from agro-waste, and it could be scaled up for commercial production.
One-pot and efficient synthesis of triazolo[1,2-a]indazole-triones via reaction of arylaldehydes with urazole and dimedone catalyzed by silica nanoparticles prepared from rice husk.

Science.gov (United States)

Hamidian, Hooshang; Fozooni, Samieh; Hassankhani, Asadollah; Mohammadi, Sayed Zia

2011-10-26

A novel synthesis of triazolo[1,2-a]indazole-1,3,8-trione derivatives by reaction of urazole, dimedone and aromatic aldehydes under conventional heating and microwave irradiation and solvent-free conditions using silica nanoparticles prepared from rice husk ash as catalyst is described. The new method features high yields, multicomponent reactions and environmental friendliness.
Evaluation of rice husk ash as filler in tread compounds

International Nuclear Information System (INIS)

Fernandes, M. R. S.; Furtado, C. R. G.; Sousa, A. M. F. de

2014-01-01

Rice which is one of the largest agriculture crops produces around 22% of rice rusk during its milling process. This material is mainly used as fuel for energy generation, which results in an ash, which disposal represents an environmental issue. The rice husk ash (RHA) contains over than 70% of silica in an amorphous form and a lot of applications is being developed for it all over the world. The use of silica as a filler in the tire industry is growing since it contributes significantly to the reduction of fuel consumption of the automobiles, allowing at the same time better traction (safety). This paper presents an evaluation of the use of RHA as filler in rubber tread compounds prepared in lab scale and compares its performance with compounds prepared with commercial silica and carbon black, the fillers normally used in tire industry. Mechanical and rheological properties are evaluated, with emphasis for tan delta as an indicator of tread performance related with rolling resistance (fuel consumption) and wet grip/traction (safety)
Evaluation of rice husk ash as filler in tread compounds

Energy Technology Data Exchange (ETDEWEB)

Fernandes, M. R. S., E-mail: monica.fernandes@lanxess.com [Lanxess Elastômeros do Brasil S.A., Brasil and Instituto de Química, Universidade do Estado do Rio de Janeiro (UERJ) (Brazil); Furtado, C. R. G., E-mail: russi@globo.com, E-mail: ana.furtado.sousa@gmail.com; Sousa, A. M. F. de, E-mail: russi@globo.com, E-mail: ana.furtado.sousa@gmail.com [Instituto de Química, Universidade do Estado do Rio de Janeiro (UERJ) (Brazil)

2014-05-15

Rice which is one of the largest agriculture crops produces around 22% of rice rusk during its milling process. This material is mainly used as fuel for energy generation, which results in an ash, which disposal represents an environmental issue. The rice husk ash (RHA) contains over than 70% of silica in an amorphous form and a lot of applications is being developed for it all over the world. The use of silica as a filler in the tire industry is growing since it contributes significantly to the reduction of fuel consumption of the automobiles, allowing at the same time better traction (safety). This paper presents an evaluation of the use of RHA as filler in rubber tread compounds prepared in lab scale and compares its performance with compounds prepared with commercial silica and carbon black, the fillers normally used in tire industry. Mechanical and rheological properties are evaluated, with emphasis for tan delta as an indicator of tread performance related with rolling resistance (fuel consumption) and wet grip/traction (safety)
Analysis of the Economic Potential for a Mercosur Rice Futures Market

OpenAIRE

Waldemar Antonio da Rocha de Souza; João Gomes Martines-Filho; Claudio Zancan; Antonio Carlos Silva Costa; Andreza Galindo Alves de Queiróz

2015-01-01

World rice production reached 488.4 thousand tons, in 2012. Asian countries are the world’s largest rice producers, followed by Latinamerica, particularly Brazil, where rice is a basic food item. In spite of the clear economic benefits bestowed by commodity futures markets, neither Asia nor Mercosur have implemented a regional rice futures market. In sum, we propose to investigate the feasibility of a Brazilian rice futures contract to serve the Mercosur region by estimating Me...
One-Pot and Efficient Synthesis of Triazolo[1,2-a]indazole-triones via Reaction of Arylaldehydes with Urazole and Dimedone Catalyzed by Silica Nanoparticles Prepared from Rice Husk

Directory of Open Access Journals (Sweden)

Asadollah Hassankhani

2011-10-01

Full Text Available A novel synthesis of triazolo[1,2-a]indazole-1,3,8-trione derivatives by reaction of urazole, dimedone and aromatic aldehydes under conventional heating and microwave irradiation and solvent-free conditions using silica nanoparticles prepared from rice husk ash as catalyst is described. The new method features high yields, multicomponent reactions and environmental friendliness.
A Tribal Story Written in Silica: Using Phytoliths to Research the Effects of Mining on Past Wild Rice (Zizania palustris) Abundance in Sandy Lake, Minnesota

Science.gov (United States)

Clarke, I. R.; Jones, M. A.; Yost, C. L.; Drake, C.; Ladwig, J. L.; Myrbo, A.; Howes, T.

2014-12-01

Wild rice (Zizania palustris, manoomin) is an emergent aquatic plant that grows annually in the northern Great Lakes region of North America. This region is also rich in iron ore deposits and correspondingly has an extensive history of mining activities. Wild rice no longer grows in some areas where it was previously abundant. Sandy Lake, located in St. Louis County on federally protected lands that are ceded territory of the Fond du Lac Band of Lake Superior Chippewa in Minnesota and downstream of the nearby U.S. Steel Minntac mine, was selected as a test site. This lake has a history of ricing activities by the Ojibwe (Chippewa) People, for whom manoomin has cultural importance. Lake cores were taken on June 17, 2014 by LacCore and FDLRM staff and samples were obtained. This project used phytolith analysis to answer the question of past wild rice presence and abundance in Sandy Lake. Phytoliths are microscopic opal silica deposits produced in some plants. Zizania palustris produces phytolith morphotypes that are unequivocally diagnostic of this species in this region. Microscopic slides were prepared and analyzed for wild rice phytoliths. Concentration values ranged from 25 to 4379 phytoliths per cm3/year, and wild rice accumulation figures ranged from 7 to 789 phytoliths/cm2/year, the maximum values of which occurred in the 1920s and generally declined to the current lowest levels observed. Mining has likely impacted wild rice populations by causing increased sulfate levels and possibly contributing to higher lake levels.
Rice husk ash as a partial replacement of cement in high strength concrete containing micro silica: Evaluating durability and mechanical properties

Directory of Open Access Journals (Sweden)

Seyed Alireza Zareei

2017-12-01

Full Text Available The preliminary and inevitable interest in the use of partial replacements or by – products as complementary pozzolanic materials was mostly induced by enforcement of air pollution control resulted from cement production industry. Rise husk is by- product taken from rice mill process, with approximately the ratio of 200 kg per one ton of rice, even in high temperature it reduces to 40 kg. This paper presents benefits resulted from various ratios of rice husk ash(RHA on concrete indicators through 5 mixture plans with proportions of 5, 10, 15, 20 and 25% RHA by weight of cement in addition to 10% micro- silica (MS to be compared with a reference mixture with 100% Portland cement. Tests results indicated the positive relationship between 15% replacement of RHA with increase in compressive strengths by about 20%. The optimum level of strength and durability properties generally gain with addition up to 20%, beyond that is associated with slight decrease in strength parameters by about 4.5%. The same results obtained for water absorption ratios likely to be unfavourable. Chloride ions penetration increased with increase in cement replacement by about 25% relative to the initial values (about less than one fifth.
Can rice field channels contribute to biodiversity conservation in Southern Brazilian wetlands?

Directory of Open Access Journals (Sweden)

Leonardo Maltchik

2011-12-01

species in agroecosystems has attracted attention. Irrigation channels can improve habitats and offer conditions for freshwater species conservation. Two questions from biodiversity conservation point of view are: 1 Can the irrigated channels maintain a rich diversity of macrophytes, macroinvertebrates and amphibians over the cultivation cycle? 2 Do richness, abundance and composition of aquatic species change over the rice cultivation cycle? For this, a set of four rice field channels was randomly selected in Southern Brazilian wetlands. In each channel, six sample collection events were carried out over the rice cultivation cycle (June 2005 to June 2006. A total of 160 taxa were identified in irrigated channels, including 59 macrophyte species, 91 taxa of macroinvertebrate and 10 amphibian species. The richness and abundance of macrophytes, macroinvertebrates and amphibians did not change significantly over the rice cultivation cycle. However, the species composition of these groups in the irrigation channels varied between uncultivated and cultivated periods. Our results showed that the species diversity found in the irrigation channels, together with the permanence of water enables these man-made aquatic networks to function as important systems that can contribute to the conservation of biodiversity in regions where the wetlands were converted into rice fields. The conservation of the species in agriculture, such as rice field channels, may be an important alternative for biodiversity conservation in Southern Brazil, where more than 90% of wetland systems have already been lost and the remaining ones are still at high risk due to the expansion of rice production. Rev. Biol. Trop. 59 (4: 1895-1914. Epub 2011 December 01.
the suitability of lime rice husk ash cement as construction material

African Journals Online (AJOL)

NIJOTECH

Enugu State University of Science and Technology, Enugu, Nigeria. ... It was therefore concluded that high percentage contents of silica, ... the Lime Rice Husk Ash cement when used as a construction material would depend ... thermal treatment of the silica in the husk .... test specimen in their moulds were stored in a.
THE COMPRESSIVE AND FLEXURAL STRENGTHS OF SELF-COMPACTING CONCRETE USING RAW RICE HUSK ASH

Directory of Open Access Journals (Sweden)

MD NOR ATAN

2011-12-01

Full Text Available This study investigates the compressive and flexural strengths of self-compacting concrete incorporating raw rice husk ash, individually and in combination with other types of mineral additives, as partial cement replacement. The additives paired with raw rice husk ash were fine limestone powder, pulverized fuel ash and silica fumes. The mix design was based on the rational method where solid constituents were fixed while water and superplasticizer contents were adjusted to produce optimum viscosity and flowability. All mixes were designed to achieve SF1 class slump-flow with conformity criteria ≥ 520 mm and ≤ 700 mm. Test results show that 15% replacement of cement using raw rice husk ash produced grade 40 concrete. It was also revealed that 30% and 45% cement replacements using raw rice husk ash combined with limestone powder and raw rice husk ash combined with limestone powder and silica fume respectively, produced comparable compressive strength to normal concrete and improved flexural strengths.
Synthesis of SiC from rice husk in a plasma reactor

Indian Academy of Sciences (India)

Unknown

air pollution and ash disposal has proven to be an unsatis- factory solution. Fortunately, rice husk contains the nece- ssary carbon and silica, intimately dispersed, to provide a nearly ideal source material for production of SiC, an industrially important ceramic material. Rice husk was first used by Cutler (1973) as a starting ...
Assessment of the rice husk lean-combustion in a bubbling fluidized bed for the production of amorphous silica-rich ash

International Nuclear Information System (INIS)

Martinez, Juan Daniel; Pineda, Tatiana; Lopez, Juan Pablo; Betancur, Mariluz

2011-01-01

Rice husk lean-combustion in a bubbling and atmospheric fluidized bed reactor (FBR) of 0.3 m diameter with expansion to 0.4 m in the freeboard zone and 3 m height was investigated. Experiment design - response surface methodology (RSM) - is used to evaluate both excess air and normal fluidizing velocity influence (independent and controllable variables), in the combustion efficiency (carbon transformation), bed and freeboard temperature and silica content in the ashes. Hot gases emissions (CO 2 , CO and NO x ), crystallographic structure and morphology of the ash are also shown. A cold fluidization study is also presented. The values implemented in the equipment operation, excess air in the range of 40-125% and normal fluidization velocities (0.13-0.15 Nm/s) show that the values near the lower limit, encourage bed temperatures around 750 o C with higher carbon transformation efficiencies around 98%. However, this condition deteriorated the amorphous potential of silica present in the ash. An opposite behavior was evidenced at the upper limit of the excess air. This thermochemical process in this type of reactor shows the technical feasibility to valorize RH producing hot gases and an amorphous siliceous raw material.
Rice husk ash as a source of silica in alkali-activated fly ash and granulated blast furnace slag systems

Directory of Open Access Journals (Sweden)

Mejía, J. M.

2013-09-01

Full Text Available This study assesses the viability of using an agro-industrial by-product, rice husk ash (RHA from a Colombian rice company’s combustion facility, as a total replacement for the commercial sodium silicate ordinarily used in alkaliactivated binders. Fly ash (FA, granulated blast furnace slag (GBFS and binary 50FA:50GBFS blended pastes were activated with a mix of sodium hydroxide and either sodium silicate or one of two types of RHA. The pastes were characterised for strength, mineralogy and microstructure. The findings showed that the agro-industrial by-product can be used to yield alkali-activated materials with 7-day mechanical strengths on the order of 42 MPa. The study confirmed that both amorphous silica and part of the crystalline silica present in RHA participate in the alkaline activation process, providing the alkalinity is suitably adjusted.Este estudio evalúa la viabilidad de utilizar un subproducto agroindustrial, la ceniza de cascarilla de arroz (RHA proveniente de un equipo combustor de una empresa Arrocera en Colombia, como reemplazo total de la sílice aportada por el silicato de sodio comercial en sistemas cementicios activados alcalinamente. Se prepararon pastas de ceniza volante (FA, de escoria de alto horno (GBFS y un sistema binario 50FA:50GBFS, que fueron activadas por una mezcla de silicato de sodio e hidróxido de sodio, y por dos tipos de RHA. Las mezclas se caracterizaron mecánica, mineralógica y microestructuralmente. Los resultados demuestran que es posible obtener materiales activados alcalinamente con resistencias mecánicas del orden de 42 MPa, a 7 días de curado, utilizando el subproducto agroindustrial. Este estudio corrobora que tanto la sílice amorfa como parte de la sílice cristalina presente en RHA tienen la posibilidad de participar en el proceso de activación alcalina, siempre y cuando las condiciones de alcalinidad estén adecuadamente ajustadas.
Use of rice husk ash as only source of silica in the formation of mesoporous materials Emprego da cinza da casca de arroz como única fonte de sílica na formação de materiais mesoporosos

Directory of Open Access Journals (Sweden)

A. J. Schwanke

2013-03-01

Full Text Available This paper reports the synthesis of molecular sieves similar to MCM-41 using rice husk ash as only source of silica. For comparison purposes, a standard synthesis was performed using aerosil 200 commercial silica. The rice husk silica was obtained by heating treatment at 600 ºC and leaching for 2 h in reflux with HCl 1mol.L-1 and used in the synthesis. The samples prepared were characterized by N2 adsorption, X-ray diffraction (XRD, scanning electronic microscopy (SEM and thermogravimetric analysis (TG. By type-IV adsorption isotherms, the formation of mesoporous materials was observed. XRD showed the formation of hexagonal unidirectional pore materials similar to MCM-41. By SEM, it could be observed that the rice husk has fibrous aspect and that synthesis using calcined and leached rice husk did not react entirely because silica was only partially dissolved.Este trabalho relata o estudo da síntese de peneiras moleculares semelhantes à MCM-41, empregando cinza da casca de arroz como única fonte de sílica. Para critérios de comparação uma síntese foi realizada com sílica comercial aerosil 200. A sílica da casca de arroz foi obtida mediante tratamento térmico a 600 ºC e lixiviação em refluxo por 2 h com HCl 1 mol/L e empregada na síntese. As amostras preparadas foram caracterizadas por adsorção de N2, difração de raios X, microscopia eletrônica de varredura (MEV e termogravimetria. Por meio das isotermas de adsorção, do tipo IV, observa-se a formação de material mesoporoso. Nos difratogramas de raios X é identificada a formação hexagonal unidirecional de poros, indicando que material apresenta semelhanças com a MCM-41. Por MEV observa-se que a casca de arroz possui aspecto fibroso e que a síntese empregando a casca de arroz calcinada e lixiviada não reagiu na sua totalidade devido a dissolução parcial da sílica.

Characterization, treatment and utilization of rice husk ash in production processes of the industrial branch

International Nuclear Information System (INIS)

Stracke, Marcelo Paulo; Schmidt, Julia Isabel; Steffen, Ana Cristina; Sokolovicz, Boris; Kieckow, Flavio

2016-01-01

The rice husk ash (CCA) is a black powder rich in silica (contents above 90%) with many industrial applications. The ash was obtained from a rice processing industry in the state of Rio Grande do Sul. In this work the purpose is to characterize the rice husk ash and eliminate the residual carbon by methods such as acid leaching. The white ash is obtained by a chemical process followed by heating between 600 and 800 °C. The results were analyzed in DR-X, TGA and DSC. The DR-X analysis showed that the samples present high levels of silica in the crystalline form of quartz, cristobalite and tridymite. The white ash was obtained with high purity and presented a good result in the manufacture of paints. (author)
A new parameter-free soft-core potential for silica and its application to simulation of silica anomalies

Energy Technology Data Exchange (ETDEWEB)

Izvekov, Sergei, E-mail: sergiy.izvyekov.civ@mail.mil; Rice, Betsy M. [Weapons and Materials Research Directorate, U.S. Army Research Laboratory, Aberdeen Proving Ground, Maryland 21005 (United States)

2015-12-28

A core-softening of the effective interaction between oxygen atoms in water and silica systems and its role in developing anomalous thermodynamic, transport, and structural properties have been extensively debated. For silica, the progress with addressing these issues has been hampered by a lack of effective interaction models with explicit core-softening. In this work, we present an extension of a two-body soft-core interatomic force field for silica recently reported by us [S. Izvekov and B. M. Rice, J. Chem. Phys. 136(13), 134508 (2012)] to include three-body forces. Similar to two-body interaction terms, the three-body terms are derived using parameter-free force-matching of the interactions from ab initio MD simulations of liquid silica. The derived shape of the O–Si–O three-body potential term affirms the existence of repulsion softening between oxygen atoms at short separations. The new model shows a good performance in simulating liquid, amorphous, and crystalline silica. By comparing the soft-core model and a similar model with the soft-core suppressed, we demonstrate that the topology reorganization within the local tetrahedral network and the O–O core-softening are two competitive mechanisms responsible for anomalous thermodynamic and kinetic behaviors observed in liquid and amorphous silica. The studied anomalies include the temperature of density maximum locus and anomalous diffusivity in liquid silica, and irreversible densification of amorphous silica. We show that the O–O core-softened interaction enhances the observed anomalies primarily through two mechanisms: facilitating the defect driven structural rearrangements of the silica tetrahedral network and modifying the tetrahedral ordering induced interactions toward multiple characteristic scales, the feature which underlies the thermodynamic anomalies.
Agricultural waste as a source for the production of silica nanoparticles.

Science.gov (United States)

Vaibhav, Vineet; Vijayalakshmi, U; Roopan, S Mohana

2015-03-15

The major interest of the paper deals with the extraction of silica from four natural sources such as rice husk, bamboo leaves, sugarcane bagasse and groundnut shell. These waste materials in large quantities can create a serious environmental problem. Hence, there is a need to adopt proper strategy to reduce the waste. In the present investigation, all the waste materials are subjected to moisture removal in a hot plate and sintered at 900°C for 7 h. The sintered powder was treated with 1 M NaOH to form sodium silicate and then with 6M H2SO4 to precipitate silica. The prepared silica powders were characterized by FT-IR, XRD and SEM-EDAX analysis. The silica recovered from different sources was found to vary between 52% and 78%. Magnesium substituted silica was formed from the groundnut waste and further treatment is required to precipitate silica. Copyright © 2014 Elsevier B.V. All rights reserved.
Analysis of the Economic Potential for a Mercosur Rice Futures Market

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Waldemar Antonio da Rocha de Souza

2015-08-01

Full Text Available World rice production reached 488.4 thousand tons, in 2012. Asian countries are the world’s largest rice producers, followed by Latinamerica, particularly Brazil, where rice is a basic food item. In spite of the clear economic benefits bestowed by commodity futures markets, neither Asia nor Mercosur have implemented a regional rice futures market. In sum, we propose to investigate the feasibility of a Brazilian rice futures contract to serve the Mercosur region by estimating Mercosur rice price dynamics and analyze basis risk and hedging effectiveness for rice market agents in the region, in a simulation framework using a hypothetical regional contract price. Sample data and period was non-probabilistic, for accessibility and convenience. Mercosur rice price dynamics expressed Argentina and Uruguay rice prices moving in synchrony. Brazil rice prices were on lower levels. Also, all three pairs of rice price series are cointegrated, with one cointegrating equation. Again, results can be largely attributed to the different price data used, in Brazil was rough rice, while in Uruguay and Argentina milled white rice with 5%. Despite that, there are preliminary evidences that a Mercosur rice futures market could be feasible.
Study on the blackbird (Agelaius ruficapillus Viellot- Emberizidae, Aves) in the rice production areas of Southern Rio Grande do Sul, Brazil : basis for a population control management program

NARCIS (Netherlands)

Silva, da J.J.C.

1999-01-01

Rice is one of the main components of the Brazilian diet. The State of Rio Grande do Sul produces approximately 4,6 millions tons per year - more than 54% of total Brazilian rice production. The average production in Southern Brazil is 5,2 tons per ha, with yields of 10 tons per ha being
Rice husks as a sustainable silica source for hierarchical flower-like metal silicate architectures assembled into ultrathin nanosheets for adsorption and catalysis.

Science.gov (United States)

Zhang, Shouwei; Gao, Huihui; Li, Jiaxing; Huang, Yongshun; Alsaedi, Ahmed; Hayat, Tasawar; Xu, Xijin; Wang, Xiangke

2017-01-05

Metal silicates have attracted extensive interests due to their unique structure and promising properties in adsorption and catalysis. However, their applications were hampered by the complex and expensive synthesis. In this paper, three-dimensional (3D) hierarchical flower-like metal silicate, including magnesium silicate, zinc silicate, nickel silicate and cobalt silicate, were for the first time prepared by using rice husks as a sustainable silicon source. The flower-like morphology, interconnected ultrathin nanosheets structure and high specific surface area endowed them with versatile applications. Magnesium silicate was used as an adsorbent with the maximum adsorption capacities of 557.9, 381.3, and 482.8mg/g for Pb 2+ , tetracycline (TC), and UO 2 2+ , respectively. Ni nanoparticles/silica (Ni NPs/SiO 2 ) exhibited high catalytic activity and good stability for 4-nitrophenol (4-NP) reduction within only ∼160s, which can be attributed to the ultra-small particle size (∼6.8nm), good dispersion and high loading capacity of Ni NPs. Considering the abundance and renewability of rice husks, metal silicate with complex architecture can be easily produced at a large scale and become a sustainable and reliable resource for multifunctional applications. Copyright © 2016 Elsevier B.V. All rights reserved.
Rapid Synthesis and Characterization of Nano sodalite Synthesized using Rice Husk Ash

International Nuclear Information System (INIS)

Siti Haslina Ahmad Rusmili; Zainab Ramli

2012-01-01

Rice husk ash (RHA) which contains more than 90 percent silica is proven to be an active silica source in zeolite synthesis. In this study, nano sodalite has been successfully synthesized hydrothermally at 60 degree Celsius using RHA as silica source in alkaline medium at various crystallization times. Commercial fumed silica was used as comparison for the silica source. Analysis by XRD has shown that pure nano sodalite was formed in 3 hours and stable up to more than 24 hours when using RHA as silica source. On the other hand, fumed silica produced pure nano sodalite only at 4 hours while a mixture of zeolites was observed outside this time range. FESEM shows a worm-like morphology of nano sodalite in the size range of 50-100 nm while FTIR shows the formation of aluminosilicates bonds. Analysis on the dissolved silica in the gel reaction mixture demonstrates the decreasing mass of silica after prolong time of crystallization which indicates the consumption of the dissolved silica in crystal growth of nano sodalite. This study shows that RHA is a better silica source in stabilizing the nano sodalite phase in oxide gel reaction mixture as compared to fumed silica. (author)
DNA tagging of blast resistant gene(s in three Brazilian rice cultivars

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S.S. Sandhu

2003-12-01

Full Text Available Rice blast is the most important fungal disease of rice and is caused by Pyricularia oryzae Sacc. (Telomorph Magnoporthe grisea Barr.. Seven randomly amplified polymorphic DNA (RAPD markers OPA5, OPG17, OPG18, OPG19, OPF9, OPF17 and OPF19 showed very clear polymorphism in resistant cultivar lines which differed from susceptible lines. By comparing different susceptible lines, nine DNA amplifications of seven primers (OPA5(1000, OPA5(1200, OPG17(700, OPG18(850, OPG19(500, OPG19(600, OPF9(600, OPF17(1200 and OPF19(600 were identified as dominant markers for the blast resistant gene in resistant cultivar lines. These loci facilitate the indirect scoring of blast resistant and blast susceptible genotypes. The codomine RAPDs markers will facilitate marker-assisted selection of the blast resistant gene in two blast resistant genotypes of rice (Labelle and Line 11 and will be useful in rice breeding programs.
Preparation of High Grade Silica from Rice Husk for Zeolite ...

African Journals Online (AJOL)

1 Department of Chemical Engineering, Ahmadu Bello University, Zaria, 810261, Nigeria. 2Department of ... Keywords: Silica; RHA; Zeolite; Synthesis; Hydrothermal; Temperature .... and the cap was quickly opened and left to cool to room.
Total Arsenic, Cadmium, and Lead Determination in Brazilian Rice Samples Using ICP-MS

OpenAIRE

Mataveli, Lidiane Raquel Verola; Buzzo, Márcia Liane; Arauz, Luciana Juncioni de; Carvalho, Maria de Fátima Henriques; Arakaki, Edna Emy Kumagai; Matsuzaki, Richard; Tiglea, Paulo

2016-01-01

This study is aimed at investigating a suitable method for rice sample preparation as well as validating and applying the method for monitoring the concentration of total arsenic, cadmium, and lead in rice by using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Various rice sample preparation procedures were evaluated. The analytical method was validated by measuring several parameters including limit of detection (LOD), limit of quantification (LOQ), linearity, relative bias, and rep...
Dietary arsenic exposure in Brazil: The contribution of rice and beans.

Science.gov (United States)

Ciminelli, Virginia S T; Gasparon, Massimo; Ng, Jack C; Silva, Gabriela C; Caldeira, Claudia L

2017-02-01

The human health risk associated with arsenic in food in Southeast Brazil was quantified. Based on the most commonly consumed food types in the Brazilian diet, the maximum inorganic As (iAs) daily intake from food (0.255 μg kg -1 body weight per day) is approximately 9% of the Benchmark Dose Lower Limit (BMDL 0.5 ) of 3 μg kg -1 body weight per day set by the World Health Organization (WHO) and Food and Agriculture Organization (FAO) Joint Expert Committee in Food Additives (JECFA). When water is included, the contribution of food to the total intake varies from 96.9% to 39.7%. Rice and beans, the main Brazilian staple food, contribute between 67 and 90% of the total As intake from food (46-79% from rice and 11-23% from beans). The substantial contribution of beans to total As food intake is reported for the first time. The broad range of As concentrations in rice and beans highlights the variable and potentially large contribution of both to As food intake in places where diet consists largely of these two food categories. Copyright © 2016 Elsevier Ltd. All rights reserved.
Use of heterogeneous CaO and SnO{sub 2} catalysts supported on rice husk ash to produce biodiesel; Emprego de catalisadores heterogeneos de CaO e SnO{sub 2} suportados em cinza de casca de arroz na obtencao de biodiesel

Energy Technology Data Exchange (ETDEWEB)

Soares, Ana Brigida [Instituto Federal do Espirito Santo, Vitoria, ES (Brazil); Silva, Paulo Roberto Nagipe da; Stumbo, Alexandre Moura, E-mail: nagipe@uenf.br [Laboratorio de Ciencias Quimicas, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, RJ (Brazil); Freitas, Jair C.C. [Departamento de Fisica, Centro de Ciencias Exatas, Universidade Federal do Espirito Santo, Vitoria, ES (Brazil)

2012-07-01

Silica obtained from rice husk after acid leaching and calcination was compared to commercial silica as a catalyst support. CaO and SnO{sub 2} catalysts were prepared by impregnation and tested in the transesterification of soybean oil and the esterification of oleic acid. CaO catalysts showed basic character and were the most active for transesterification, whereas SnO{sub 2} catalysts were acid and the most effective for esterification. In both cases the performances of the catalysts prepared with rice husk ash and commercial silica were similar. These results demonstrate that rice husk is a cost-effective and environmentally-friendly source of silica that can be used as a catalyst support. (author)
Occurrence of Aspergillus section Flavi and aflatoxins in Brazilian rice: From field to market

DEFF Research Database (Denmark)

Katsurayama, Aline M.; Martins, Ligia Manoel; Iamanaka, Beatriz T.

2018-01-01

The guarantee of the high quality of rice is of utmost importance because any toxic contaminant may affect consumer health, especially in countries such as Brazil where rice is part of the daily diet. A total of 187 rice samples, from field, processing and market from two different production sys...
ERICA: intake of macro and micronutrients of Brazilian adolescents

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Amanda de Moura Souza

2016-02-01

Full Text Available ABSTRACT OBJECTIVE To describe food and macronutrient intake profile and estimate the prevalence of inadequate micronutrient intake of Brazilian adolescents. METHODS Data from 71,791 adolescents aged from 12 to 17 years were evaluated in the 2013-2014 Brazilian Study of Cardiovascular Risks in Adolescents (ERICA. Food intake was estimated using 24-hour dietary recall (24-HDR. A second 24-HDR was collected in a subsample of the adolescents to estimate within-person variability and calculate the usual individual intake. The prevalence of food/food group intake reported by the adolescents was also estimated. For sodium, the prevalence of inadequate intake was estimated based on the Tolerable Upper Intake Level (UL. The Estimated Average Requirement (EAR method used as cutoff was applied to estimate the prevalence of inadequate nutrient intake. All the analyses were stratified according to sex, age group and Brazilian macro-regions. All statistical analyses accounted for the sample weight and the complex sampling design. RESULTS Rice, beans and other legume, juice and fruit drinks, breads and meat were the most consumed foods among the adolescents. The average energy intake ranged from 2,036 kcal (girls aged from 12 to 13 years to 2,582 kcal (boy aged from14 to 17 years. Saturated fat and free sugar intake were above the maximum limit recommended ( 50.0%. Sodium intake was above the UL for more than 80.0% of the adolescents. CONCLUSIONS The diets of Brazilian adolescents were characterized by the intake of traditional Brazilian food, such as rice and beans, as well as by high intake of sugar through sweetened beverages and processed foods. This food pattern was associated with an excessive intake of sodium, saturated fatty acids and free sugar.
Evaluation of metal ions in rice samples: extraction and direct determination by ICP OES

International Nuclear Information System (INIS)

Oliveira, Andrea; Cadore, Solange; Baccan, Nivaldo

2012-01-01

A method for extraction of metal ions present in rice samples using ammoniacal EDTA solution, pH = 10, as extractor agent is proposed under the following optimized conditions: 0.20 g of rice sample and 5.00 mL of ammoniacal EDTA (ethylenediaminetetraacetic acid) solution, with 5 min of ultrasound exposure time. Using robust ICP OES (inductively coupled plasma atomic emission spectrometry) conditions, direct analysis of the extraction solution was allowed, and the recovery values obtained were above 90% for most of the studied elements (P, K, Mg, Ca, Zn, Mn, Cu and Mo) with RSD -1 (Mn) - 48.68 mg kg -1 (K), showing adequate detectability for the determination of the analytes. The analysis of different samples indicated that Brazilian 'integral' rice contains higher contents of the constituents studied, followed by 'parboiled' rice, and the 'agulhinha' rice a long and thin grain type. (author)
A lucrative chemical processing of bamboo leaf biomass to synthesize biocompatible amorphous silica nanoparticles of biomedical importance

Science.gov (United States)

Rangaraj, Suriyaprabha; Venkatachalam, Rajendran

2017-06-01

Synthesis of silica nanoparticles from natural resources/waste via cost effective route is presently one of the anticipating strategies for extensive applications. This study reports the low-cost indigenous production of silica nanoparticles from the leftover of bamboo (leaf biomass) through thermal combustion and alkaline extraction, and examination of physico-chemical properties and yield percentage using comprehensive characterization tools. The outcome of primed silica powder exhibits amorphous particles (average size: 25 nm) with high surface area (428 m2 g-1) and spherical morphology. Despite the yield percentage of silica nanoparticles from bamboo leave ash is 50.2%, which is less than rice husk ask resources (62.1%), the bamboo waste is only an inexpensive resource yielding high purity (99%). Synthesis of silica nanoparticles from natural resources/waste with the help of lucrative route is at present times one of the anticipating strategies for extensive applications. In vitro study on animal cell lines (MG-63) shows non-toxic nature of silica nanoparticles up to 125 µg mL-1. Hence, this study highlights the feasibility for the mass production of silica nanoparticles from bamboo leave waste rather using chemical precursor of silica for drug delivery and other medical applications.
Growth and physiological responses of maize (Zea mays L.) to porous silica nanoparticles in soil

Energy Technology Data Exchange (ETDEWEB)

Suriyaprabha, R.; Karunakaran, G.; Yuvakkumar, R.; Prabu, P.; Rajendran, V., E-mail: veerajendran@gmail.com [K. S. Rangasamy College of Technology, Centre for Nano Science and Technology (India); Kannan, N. [K. S. Rangasamy College of Arts and Science, Department of Biotechnology (India)

2012-12-15

The present study aims to explore the effect of high surface area (360.85 m{sup 2} g{sup -1}) silica nanoparticles (SNPs) (20-40 nm) extracted from rice husk on the physiological and anatomical changes during maize growth in sandy loam soil at four concentrations (5-20 kg ha{sup -1}) in comparison with bulk silica (15-20 kg ha{sup -1}). The plant responses to nano and bulk silica treatments were analyzed in terms of growth characteristics, phyto compounds such as total protein, chlorophyll, and other organic compounds (gas chromatography-mass spectroscopy), and silica accumulation (high-resolution scanning electron microscopy). Growth characteristics were much influenced with increasing concentration of SNPs up to 15 kg ha{sup -1} whereas at 20 kg ha{sup -1}, no significant increments were noticed. Silica accumulation in leaves was high at 10 and 15 kg ha{sup -1} (0.57 and 0.82 %) concentrations of SNPs. The observed physiological changes show that the expression of organic compounds such as proteins, chlorophyll, and phenols favored to maize treated with nanosilica especially at 15 kg ha{sup -1} compared with bulk silica and control. Nanoscale silica regimes at 15 kg ha{sup -1} has a positive response of maize than bulk silica which help to improve the sustainable farming of maize crop as an alternative source of silica fertilizer.
Preliminary analysis of geothermal aspects of Brazilian thermal spring

International Nuclear Information System (INIS)

Hurter, S.J.; Hamza, V.M.

1982-01-01

Information on more than 400 geothermal springs in Brazil has been assembled. On the basis of the data colected the temperatures at the maximum depths of circulation of spring waters are calculated using the quality of silica dissolved in water. For some thermal springs temperatures are calculated on the basis of silica determination carrried out by us. Applying linear relations between silica temperature and geothermal flux the average depths of water circulation in the Parana Basin and the Brazilian folded belts surrounding the San Francisco craton are calculated. The radioactivity of the water, derived mainly from the dissolved radon can be correlated with the temperature of the spring. An inverse correlation, as was observed for thermal springs of Pocos de Caldas, can be used to calculate the ascent velocity of thermal waters, where as, a positive correlations could be interpreted as due to the mixing of thermal with surface waters. (Author) [pt
ENCAPSULATION OF HORSERADISH PEROXIDASE-GLUCOSE OXIDASE (HRP-GOx IN SILICA AQUAGEL SYNTHESIZED FROM RICE HULL ASH FOR ENZYMATIC REACTION OF GLUCOSE

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Nuryono Nuryono

2010-06-01

Full Text Available In recent years, the sol-gel technique has attracted increasing interest as a unique approach to immobilize biomolecules for bioanalytical applications as well as biochemical and biophysical studies. In this research, encapsulation of Horseradish peroxidase-Glucose oxidase (HRP-GOx enzymes in silica aquagel from rice hull ash by sol-gel process has been carried out. In addition, the effect of several parameters (weight ratio of HRP to GOx, pH, temperature, sodium ion concentration on enzyme activity was studied, as well. Rice hull ash, which was produced by ashing at 700 °C, was extracted it's silika by NaOH solution 1 M at 100 °C for two hours to produce sodium silikate (Na2SiO3 solution. The Na2SiO3 solution with pH of 13 was added with a strong cation exchanger resin, to produce sol solution with the pH of 4. Encapsulation was emphasized by mixing sol solution and phosphate buffer pH 7 containing HRP-GOx solution at volume ratio of buffer to sol solution 1:5. The mixture was transferred into 96-microwell plate and was aged for 24 hours. Enzymatic reaction was carried out by adding chromogenic solution of phenol and 4-aminoantipyrine (4-AAP and b-D-glucose solution (as substrate into the microwell. Enzymatic activity was examined by measuring absorbance of product solution at 490 nm with ELISA reader. Result of enzymatic activity for encapsulated enzymes (SGE was compared to that for free enzymes (EB. Results showed that at the investigated condition, HRP-GOx enzymes gave high activity at weight ratio of HRP to GOx 10:1 and pH 7 for both SGE and EB. Encapsulation caused the enzymes activity decrease to 53.0±0.2 %. However, SGE was observed to be more stable on pH and temperature changes than EB. Study on the effect of sodium concentration showed that the increase of sodium concentration from 0.10 to 0.37 M decreased the enzymatic activity to 56±0.2%. Reusability test showed that the synthesized SGE was reusable with activity decrease of 60
The efficiency of biosynthesis silica nanoparticles at removal of heavy metals Cr and Cu from aqueous solutions

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Mohammad Hossein Sayadi

2017-05-01

Full Text Available Background and Aim: Nanotechnology considered as one of the main management strategy in reducing negative effects of water pollution, which leads to treating of water inexpensive and more effective. This study aimed to investigate the removal of Cr and Cu from aqueous solutions using nano-silicate which is synthesized by rice husk. Materials and Methods: In the present study, functionalized nano-silica with rice husk was fabricated and characterized by FT-IR، TEM, SEM and XRD. The effect of adsorbent dosage, initial concentration and equilibrium of chromium and copper and contact time in removal of mentioned heavy metals were investigated. Finally, the adsorption isotherms were analyzed. Results: The silica nanoparticles had nearly spherical morphology with a uniform size of about 80 nm. However, the obtained functionalized silica nanoparticles were spherical (about 90 nm in diameter. Results showed that optimum adsorption of Cr and Cu contaminant obtained at 100 minutes, while the optimum amount of adsorbent for Cr and Cu were 125 and 100 mg respectively. The optimal concentration of Cr and Cu was 2 mg/l. The correlation coefficients of adsorption isotherms of Cr (R2Langmuir =0.9946 and Cu (R2Langmuir =0.999 showed the good agreement between the adsorption data and Langmuir model. Conclusion: The study showed that the silica nanoparticles can be produced using agricultural waste as a inexpensive and environmentally friendly method and can be used to removing of contaminants from the aquatic environment.

Biomass saccharification is largely enhanced by altering wall polymer features and reducing silicon accumulation in rice cultivars harvested from nitrogen fertilizer supply.

Science.gov (United States)

Zahoor; Sun, Dan; Li, Ying; Wang, Jing; Tu, Yuanyuan; Wang, Yanting; Hu, Zhen; Zhou, Shiguang; Wang, Lingqiang; Xie, Guosheng; Huang, Jianliang; Alam, Aftab; Peng, Liangcai

2017-11-01

In this study, two rice cultivars were collected from experimental fields with seven nitrogen fertilizer treatments. All biomass samples contained significantly increased cellulose contents and reduced silica levels, with variable amounts of hemicellulose and lignin from different nitrogen treatments. Under chemical (NaOH, CaO, H 2 SO 4 ) and physical (hot water) pretreatments, biomass samples exhibited much enhanced hexoses yields from enzymatic hydrolysis, with high bioethanol production from yeast fermentation. Notably, both degree of polymerization (DP) of cellulose and xylose/arabinose (Xyl/Ara) ratio of hemicellulose were reduced in biomass residues, whereas other wall polymer features (cellulose crystallinity and monolignol proportion) were variable. Integrative analysis indicated that cellulose DP, hemicellulosic Xyl/Ara and silica are the major factors that significantly affect cellulose crystallinity and biomass saccharification. Hence, this study has demonstrated that nitrogen fertilizer supply could largely enhance biomass saccharification in rice cultivars, mainly by reducing cellulose DP, hemicellulosic Xyl/Ara and silica in cell walls. Copyright © 2017 Elsevier Ltd. All rights reserved.
Fermentation Quality and Additives: A Case of Rice Straw Silage

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Yusuff Oladosu

2016-01-01

Full Text Available Rice cultivation generates large amount of crop residues of which only 20% are utilized for industrial and domestic purposes. In most developing countries especially southeast Asia, rice straw is used as part of feeding ingredients for the ruminants. However, due to its low protein content and high level of lignin and silica, there is limitation to its digestibility and nutritional value. To utilize this crop residue judiciously, there is a need for improvement of its nutritive value to promote its utilization through ensiling. Understanding the fundamental principle of ensiling is a prerequisite for successful silage product. Prominent factors influencing quality of silage product include water soluble carbohydrates, natural microbial population, and harvesting conditions of the forage. Additives are used to control the fermentation processes to enhance nutrient recovery and improve silage stability. This review emphasizes some practical aspects of silage processing and the use of additives for improvement of fermentation quality of rice straw.
Fermentation Quality and Additives: A Case of Rice Straw Silage.

Science.gov (United States)

Oladosu, Yusuff; Rafii, Mohd Y; Abdullah, Norhani; Magaji, Usman; Hussin, Ghazali; Ramli, Asfaliza; Miah, Gous

2016-01-01

Rice cultivation generates large amount of crop residues of which only 20% are utilized for industrial and domestic purposes. In most developing countries especially southeast Asia, rice straw is used as part of feeding ingredients for the ruminants. However, due to its low protein content and high level of lignin and silica, there is limitation to its digestibility and nutritional value. To utilize this crop residue judiciously, there is a need for improvement of its nutritive value to promote its utilization through ensiling. Understanding the fundamental principle of ensiling is a prerequisite for successful silage product. Prominent factors influencing quality of silage product include water soluble carbohydrates, natural microbial population, and harvesting conditions of the forage. Additives are used to control the fermentation processes to enhance nutrient recovery and improve silage stability. This review emphasizes some practical aspects of silage processing and the use of additives for improvement of fermentation quality of rice straw.
Phosphorus Use Efficiency by Brazilian Upland Rice Genotypes Evaluated by the {sup 32}P Dilution Technique

Energy Technology Data Exchange (ETDEWEB)

Franzini, V. I.; Mendes, F. L. [Brazilian Agricultural Research Corporation, EMBRAPA-Amazonia Oriental, Belem, PA (Brazil); Muraoka, T.; Da Silva, E. C. [Center for Nuclear Energy in Agriculture, University of Sao Paulo, Piracicaba, SP (Brazil); Adu-Gyamfi, J. J. [Soil and Water Management and Crop Nutrition Laboratory, International Atomic Energy Agency, Vienna (Austria)

2013-11-15

The objectives of this work were to identify the most efficient upland rice genotypes in phosphorus (P) utilization, and to verify if P from the seed affects the classification of upland rice genotypes on P uptake efficiency. The experiment was conducted in a greenhouse of the Center for Nuclear Energy in Agriculture (CENA/USP), Piracicaba, Sao Paulo, Brazil, using the {sup 32}P isotope technique, and plants were grown in pots with samples of dystrophic Typic Haplustox (Oxisol). The experimental design was completely randomized with four replications. The treatments consisted of 47 upland rice genotypes and two standard plant species, efficient or inefficient in P uptake. The results were assessed through correlation and cluster analysis (multivariate). The Carisma upland rice genotype was the most efficient in P uptake, and Caripuna was the most efficient on P utilization. The P derived from seed does not influence the identification of upland rice genotypes in P uptake efficiency. (author)
Process Development in the Preparation and Characterization of Silicon Alkoxide From Rice Husk

International Nuclear Information System (INIS)

Khin San Win; Toe Shein; Nyunt Wynn

2011-12-01

The preparation and characterization of silicon alkoxide (silicon isopropoxide) from rice husk char has been studied. In the investigation, four kinds of Myanmar paddies were chemically assayed. Analyses showed the silicon contend varies from 73-92% . Based on the silicon content, the process development in the production of silicon isopropoxide was carried out. In the process development, silicon isopropoxide with a yield of 44.21% was achieved by the direct reaction of isopropanol in situ by silicon tetrachloride, which was directly produced by the chlorination of rice husk char at the high temperature range of 900-1100 C. The novelity of the process was that, silicon isopropoxide was achieved in situ and not by using the old process, where generally isopropanol was reacted with silicon tetrachloride. The physiochemical properties of silicon isopropoxide was confirmed by conventional and modern techniques. In the investigation, the starting materials, silica in the reaction products were characterized, identified and confirmed by modren techniques. Silicon isopropoxide can be a sources of pore silica whereby silicon of 97-99% of purity can be achieved.
Novel uses of rice-husk-ash (a natural silica-carbon matrix) in low-cost water purification applications

Science.gov (United States)

Malhotra, Chetan; Patil, Rajshree; Kausley, Shankar; Ahmad, Dilshad

2013-06-01

Rice-husk-ash is used as the base material for developing novel compositions to deal with the challenge of purifying drinking water in low-income households in India. For example, rice-husk-ash cast in a matrix of cement and pebbles can be formed into a filtration bed which can trap up to 95% of turbidity and bacteria present in water. This innovation was proliferated in villages across India as a do-it-yourself rural water filter. Another innovation involves embedding silver nanoparticles within the rice husk ash matrix to create a bactericidal filtration bed which has now been commercialized in India as a low-cost for-profit household water purifier. Other innovations include the impregnation of rice-husk-ash with iron hydroxide for the removal of arsenic from water and the impregnation of rice-husk ash with aluminum hydroxide for the removal of fluoride ions from water which together have the potential to benefit over 100 million people across India who are suffering from the health effects of drinking groundwater contaminated with arsenic and fluoride.
Conversion of rice hull ash into soluble sodium silicate

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Edson Luiz Foletto

2006-09-01

Full Text Available Sodium silicate is used as raw material for several purposes: silica gel production, preparation of catalysts, inks, load for medicines, concrete hardening accelerator, component of detergents and soaps, refractory constituent and deflocculant in clay slurries. In this work sodium silicate was produced by reacting rice hull ash (RHA and aqueous sodium hydroxide, in open and closed reaction systems. The studied process variables were time, temperature of reaction and composition of the reaction mixture (expressed in terms of molar ratios NaOH/SiO2 and H2O/SiO2. About 90% silica conversion contained in the RHA into sodium silicate was achieved in closed system at 200 °C. The results showed that sodium silicate production from RHA can generate aggregate value to this residue.
Adubarroz: a brazilian experience for fertilization and liming recommendation of irrigated rice via computational system

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Felipe de Campos Carmona

Full Text Available ABSTRACT: Recommendations for fertilizing irrigated rice in southern Brazil have been constantly evolving over years. In this process, the influence of factors such as the development cycle of varieties and sowing period increased. Thus, computational tools that take these and others important aspects into account can potentiate the fertilization response of rice. This study describes the computer program "ADUBARROZ". The software provides recommendations of fertilizer rates and liming requirements of irrigated rice, based on information entered by the user. The system takes various factors that regulate the crop response to fertilization into account. A final report is established with the graphical representation of input management over time.
Mechanical properties of epoxy composites with plasma-modified rice-husk-derived nanosilica

Science.gov (United States)

Hubilla, Fatima Athena D.; Panghulan, Glenson R.; Pechardo, Jason; Vasquez, Magdaleno R., Jr.

2018-01-01

In this study, we explored the use of rice-husk-derived nanosilica (nSiO2) as fillers in epoxy resins. The nSiO2 was irradiated with a capacitively coupled 13.56 MHz radio frequency (RF) plasma using an admixture of argon (Ar) and hexamethyldisiloxane (HMDSO) or 1,7-octadiene (OD) monomers. The plasma-polymerized nSiO2 was loaded at various concentrations (1-5%) into the epoxy matrix. Surface hydrophobicity of the plasma-treated nSiO2-filled composites increased, which is attributed to the attachment of functional groups from the monomer gases on the silica surface. Microhardness increased by at least 10% upon the inclusion of plasma-modified nSiO2 compared with pristine nSiO2-epoxy composites. Likewise, hardness increased with increasing loading volume, with the HMDSO-treated silica composite recording the highest increase. Elastic moduli of the composites also showed an increase of at least 14% compared with untreated nSiO2-filled composites. This work demonstrated the use of rice husk, an agricultural waste, as a nSiO2 source for epoxy resin fillers.
Characterization, treatment and utilization of rice husk ash in production processes of the industrial branch; Caracterizacao, tratamento e aproveitamento das cinzas da casca do arroz em processos produtivos do ramo industrial

Energy Technology Data Exchange (ETDEWEB)

Stracke, Marcelo Paulo; Schmidt, Julia Isabel; Steffen, Ana Cristina; Sokolovicz, Boris; Kieckow, Flavio, E-mail: stracke@santoangelo.uri.br [Universidade Regional Integrada do Alto Uruguai e das Missoes (URI), Santo Angelo, RS (Brazil)

2016-07-01

The rice husk ash (CCA) is a black powder rich in silica (contents above 90%) with many industrial applications. The ash was obtained from a rice processing industry in the state of Rio Grande do Sul. In this work the purpose is to characterize the rice husk ash and eliminate the residual carbon by methods such as acid leaching. The white ash is obtained by a chemical process followed by heating between 600 and 800 °C. The results were analyzed in DR-X, TGA and DSC. The DR-X analysis showed that the samples present high levels of silica in the crystalline form of quartz, cristobalite and tridymite. The white ash was obtained with high purity and presented a good result in the manufacture of paints. (author)
Use of seed protein polymorphism for discrimination of improvement level and geographic origin of upland rice cultivars

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Ricardo Montalván

1998-12-01

Full Text Available Grain proteins from 58 Brazilian and nine Japanese upland rice cultivars (Oryza sativa L. were electrophoretically separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE. Densitometric scanning of the electrophoretic profiles permitted the estimation of the relative concentration of 16 protein fractions, which were used as variables for the calculation of Fisher's canonical discriminating functions. Significant differences between mean values of protein fractions were useful in distinguishing Brazilian and Japanese cultivars, as well as improved and non-improved Brazilian rice cultivars in scattered plots. Electrophoretically detectable protein polymorphism in rice grain can indicate geographic origin as well as breeding improvement level of a cultivar. Improved cultivars were those released by plant breeding institutes.Proteínas de grão de 58 genótipos de arroz brasileiro e nove japoneses foram separadas por meio de eletroforese (SDS-PAGE. A observação densitométrica dos perfis eletroforéticos permitiu avaliar as concentrações relativas de 16 frações protéicas que foram usadas como variáveis para a estimativa de funções discriminantes de Fisher. Diferenças significantes foram encontradas entre as frações protéicas dos grupos brasileiros e japoneses, assim como entre os genótipos melhorados e não melhorados. O polimorfismo protéico detectável eletroforetica-mente nos grãos de arroz pode indicar a origem geográfica e o nível de melhoramento dos cultivares.
A practicable detection system for genetically modified rice by SERS-barcoded nanosensors.

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Chen, Kun; Han, Heyou; Luo, Zhihui; Wang, Yanjun; Wang, Xiuping

2012-04-15

Since the global cultivation of genetically modified crops constantly expands, it remains a high demand to establish different ways to sort food and feed that consist or contain genetically modified organisms. Surface-enhanced Raman scattering (SERS) spectroscopy is a flexible tool for biological analysis due to its excellent properties for detecting wide varieties of target biomolecules including nucleic acids. In the present study, a SERS-barcoded nanosensor was developed to detect Bacillus thuringiensis (Bt) gene-transformed rice expressing insecticidal proteins. The barcoded sensor was designed by encapsulation of gold nanoparticles with silica and conjugation of oligonucleotide strands for targeting DNA strands. The transition between the cry1A(b) and cry1A(c) fusion gene sequence was used to construct a specific SERS-based detection method with a detection limit of 0.1 pg/mL. In order to build the determination models to screen transgene, a series mixture of Bt rice and normal rice were prepared for SERS assay, and the limit of detection was 0.1% (w/w) transgenic Bt rice relative to normal rice. The sensitivity and accuracy of the SERS-based assay was comparable with real-time PCR. The SERS-barcoded analytical method would provide precise detection of transgenic rice varieties but also informative supplement to avoid false positive outcomes. Crown Copyright Â© 2012. Published by Elsevier B.V. All rights reserved.
Effect of sintering temperature variations on fabrication of 45S5 bioactive glass-ceramics using rice husk as a source for silica.

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Leenakul, Wilaiwan; Tunkasiri, Tawee; Tongsiri, Natee; Pengpat, Kamonpan; Ruangsuriya, Jetsada

2016-04-01

45S5 bioactive glass is a highly bioactive substance that has the ability to promote stem cell differentiation into osteoblasts--the cells that create bone matrix. The aim of this work is to analyze physical and mechanical properties of 45S5 bioactive glass fabricated by using rice husk ash as its silica source. The 45S5 bioactive glass was prepared by melting the batch at 1300 °C for 3h. The samples were sintered at different temperatures ranging from 900 to 1050 °C with a fixed dwell-time of 2h. The phase transitions, density, porosity and microhardness values were investigated and reported. DTA analysis was used to examine the crystallization temperatures of the glasses prepared. We found that the sintering temperature had a significant effect on the mechanical and physical properties of the bioactive glass. The XRD showed that when the sintering temperature was above 650 °C, crystallization occurred and bioactive glass-ceramics with Na2Ca2Si3O9, Na2Ca4(PO4)2SiO4 and Ca3Si2O7 were formed. The optimum sintering temperature resulting in maximum mechanical values was around 1050 °C, with a high density of 2.27 g/cm(3), 16.96% porosity and the vicker microhardness value of 364HV. Additionally, in vitro assay was used to examine biological activities in stimulated body fluid (SBF). After incubation in SBF for 7 days, all of the samples showed formations of apatite layers indicating that the 45S5 bioactive glasses using rice husk as a raw material were also bioactive. Copyright © 2015 Elsevier B.V. All rights reserved.
Pore Water Arsenic Dynamics in Rice Paddies Under Projected Future Climates

Science.gov (United States)

Plaganas, M.; Wang, T.; Muehe, E. M.; Fendorf, S. E.

2016-12-01

Rice is one of the staple crops in the world, with 50% of the global population eating rice daily. Many rice-producing regions of the world are irrigated with groundwater contaminated with arsenic (As), and in particular South and Southeast Asia, where geogenic As is leached into the groundwater. Use of groundwater pervasively high in As leads to subsequent accumulation in paddy soils. Arsenic, a toxic metalloid, also decreases rice productivity and further jeopardizes food security. Hence, rice agriculture is concerned with its productivity in a climate change impacted future and the particular impacts of arsenic on yields. However, past studies do not address the prevalence of As in paddy soils or its fate in the rhizosphere and ultimate impact on the plant. The objective of our study was to determine changes in pore water As dynamics in the rhizosphere of rice plants grown on As-contaminated paddy soil under climate conditions projected for the end of the century. In order to address this objective, we designed greenhouse chambers with today's climate and projected climate conditions for the year 2100, specifically 5°C increase in temperature and doubled concentration of atmospheric CO2. We hypothesize that the effects of climate change with these conditions will increase the mobility of As in the rhizosphere, and thus, decrease rice growth in As-bearing paddies more than, so far, expected. We examined pore water geochemistry including pH and As concentrations, and correlate that to the height of the plants. Furthermore, the dynamics of other elements in the pore water such as carbon, iron, sulfur, manganese, and silica are further evaluated for their effects on rice growth. Arsenic will have an impact on rice production and conditions induced by future climatic conditions need to be considered for food security. Considering that climate change will decrease the global agricultural output, we should urgently consider adapting our agricultural practices to aid
Adsorption of lead and copper ions from aqueous effluents on rice husk ash in a dynamic system

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M. G. A. Vieira

2014-06-01

Full Text Available This study evaluated the kinetic adsorption of Pb and Cu ions using rice husk ash as adsorbent in a fixed bed. The maximum adsorption capacities obtained for lead and copper ions in the fixed bed were 0.0561 and 0.0682 mmol/g (at 20 ºC, respectively. The thermodynamic studies indicated that the lead adsorption process was exothermic and spontaneous, while the copper adsorption process was endothermic and spontaneous. Characterization results indicated the presence of several functional groups, amorphous silica and a fibrous and longitudinal structure of rice husks. Rice husk ash (RHA from northern Brazil can be used as a bioadsorbent for the individual removal of Pb(II and Cu(II ions from metal-containing effluents.
Thermoelectric properties and nanostructures of materials prepared from rice husk ash

Energy Technology Data Exchange (ETDEWEB)

Pukird, S.; Tipparach, U.; Kasian, P. [Ubon Ratchathani Univ., Ubon Ratchathani (Thailand). Dept. of Physics; Limsuwan, P. [King Mongkut' s Univ. of Technology Thonburi, Bangkok (Thailand). Dept. of Physics

2009-07-01

Thailand produces large amounts of agricultural residues such as rice husk and coconut shells. Rice husk is considered to be a potential source for solar grade silicon. Studies have shown that reasonably pure polycrystalline silicon can be prepared from rice husk white ash by a metallothermic reduction process. This paper reported on a study that investigated the thermoelectric properties of ceramic material prepared by mixing silica from rice husk ash and carbon obtained from coconut shell charcoal. The thermoelectric properties of the materials were examined along with their microstructures. The materials were made from burning rice husk ash and coconut shell at different temperatures and then doped with metal oxides. Pellets were heated at temperature of 700 degrees C for 1-3 hours. The voltage on both sides of the pellets was observed. The electromotive force was found when different temperatures were applied on both sides of the pellet specimens. The Seebeck coefficient was then calculated. The results showed that these materials can be used as thermoelectric devices. Scanning electron microscope (SEM) and energy dispersive X-rays (EDX) were used to investigate the source of materials and the products on the substrates. The images of SEM and EDX showed nanostructures of materials such as nanowires, nanorods and nanoparticles of the products and sources. 22 refs., 2 tabs., 9 figs.
Hunger, food and drink in Brazilian popular music: a brief overview.

Science.gov (United States)

de Vasconcelos, Francisco de Assis Guedes; Vasconcelos, Mariana Perrelli; de Vasconcelos, Iris Helena Guedes

2015-01-01

The article reflects on how the themes of hunger, consumption of soft drinks and consumption of beans and rice are addressed in Brazilian popular music. We investigate the years of military dictatorship (1964-1985). The focus of the analysis is on the so-called protest song, a musical genre characterized by aesthetic, cultural, political, ideological and social criticism to military rule. The study of the ideology and philosophy of language of Mikhail Bakhtin is the theoretical reference; especially his concepts of "ideological sign" and "word." Analysis reveals that the protest song portrayed elements of the economic, political and social contexts and led to the diffusion of healthy or unhealthy eating habits or ideologies, contributing to the construction of the Brazilian dietary identity.
Selective intake of potassium from K-bearing silicate minerals by sunflower and upland rice inferred from Eu anomaly. Implication for weathering as a direct consequence of plant physiology

International Nuclear Information System (INIS)

Akagi, Tasuku; Saito, Sakura; Watanabe, Shin-ichi; Sugiyama, Megumi; Ae, Noriharu

2006-01-01

Two crops (sunflower and upland rice) cultivated using three K-bearing minerals and KCl by Sugiyama and Ae (2000) were analyzed for rare earth elements (REEs). The two crops had been reported by them to general more available silica in soil (especially in the case of sunflower) and absorbed silica in plants (especially in the case of upland rice) than that available originally in soil. The K-bearing minerals included biotite, muscovite, and K-feldspar. The REE patterns of individual crop specimens exhibited different extents of Eu anomaly; upland rice exhibited more varying extent of Eu anomaly than sunflower. It is inferred that REEs released from the K-bearing minerals had a longer contact with soil in the case of sunflower than in the case of upland rice. By the scrutiny of the extent of the Eu anomaly, it was found that upland rice took in K and REEs from all the K-bearing minerals, including hardly-soluble feldspar. Eu anomaly can be a good proxy of sources of inorganic nutrients in plants as well as of the directness of absorption of the nutrients. When the present results are viewed from a different angle, they endorse that plant-induced weathering is equivalent to physiological action of plants. (author)
ADSORPSI ION SIANIDA DALAM LARUTAN MENGGUNAKAN ADSORBEN HIBRIDA AMINOPROPIL SILIKA GEL DARI SEKAM PADI TERIMPREGNASI ALUMINIUM (Adsorption of Cyanide Ions in Solution Using a Hybrid Adsorbent Aminopropyl Silica Gel from Rice Husks of Impregnated With

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Amaria Amaria

2012-03-01

aminopropil silica gel from rice husk that has been impregnated with aluminum (APSG-Al and silica gel impregnated with aluminum (SG-Al of rice husk silica gel as the material for the adsorption of cyanide ions in solution. The interaction between the adsorbent with cyanide ions in solution performed in a batch system. The parameters examined in this study were the influence of medium pH, the effect of interaction time and the effect of initial concentration of cyanide ion adsorption ability of adsorbent hybrid amino silica gel impregnated with aluminum. Quantitative Analysis of cyanide ions left in the filtrate was tested by means of ion selective electrode. The effect of interaction time data were analyzed with kinetic model, the data of the influence of cyanide ion concentration was analyzed by Langmuir adsorption isotherm model and Freundlich. The results showed that the infrared spectroscopic identification results show APSG-Al adsorbent has silanol groups (Si-OH, siloxil (Si-O-Si, primary amine group, NH2. The result of XRD analysis of the price of 2θ at 65.51 indicates that the aluminum impregnated with the silica in the form of alumina Al2O3. The result of adsorption of cyanide by the hybrid silica gel impregnated with aluminum aminopropil (APSG-Al showed maximum adsorption occurred at pH 5 was 67.62%, silica gel impregnated with aluminum was 51,11%. Study the kinetics of the effect of interaction time showed that the adsorbent APSG-Al and SG-Al-Al has the adsorption rate constant k1 is 2.7, 10-3and 1.9,10-3 min-1, respectively. Adsorption equilibrium data showed that the adsorbent APSG-Al and SG-Al tend to follow the adsorption isotherm model Freundlich.
Environmentally-Friendly Dense and Porous Geopolymers Using Fly Ash and Rice Husk Ash as Raw Materials

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Daniele Ziegler

2016-06-01

Full Text Available This paper assesses the feasibility of two industrial wastes, fly ash (FA and rice husk ash (RHA, as raw materials for the production of geopolymeric pastes. Three typologies of samples were thus produced: (i halloysite activated with potassium hydroxide and nanosilica, used as the reference sample (HL-S; (ii halloysite activated with rice husk ash dissolved into KOH solution (HL-R; (iii FA activated with the alkaline solution realized with the rice husk ash (FA-R. Dense and porous samples were produced and characterized in terms of mechanical properties and environmental impact. The flexural and compressive strength of HL-R reached about 9 and 43 MPa, respectively. On the contrary, the compressive strength of FA-R is significantly lower than the HL-R one, in spite of a comparable flexural strength being reached. However, when porous samples are concerned, FA-R shows comparable or even higher strength than HL-R. Thus, the current results show that RHA is a valuable alternative to silica nanopowder to prepare the activator solution, to be used either with calcined clay and fly ash feedstock materials. Finally, a preliminary evaluation of the global warming potential (GWP was performed for the three investigated formulations. With the mix containing FA and RHA-based silica solution, a reduction of about 90% of GWP was achieved with respect to the values obtained for the reference formulation.

Photocatalytic removal of Congo red dye using MCM-48/Ni2O3 composite synthesized based on silica gel extracted from rice husk ash; fabrication and application.

Science.gov (United States)

Shaban, Mohamed; Abukhadra, Mostafa R; Hamd, Ahmed; Amin, Ragab R; Abdel Khalek, Ahmed

2017-12-15

MCM-48 mesoporous silica was successfully synthesized from silica gel extracted from rice husk ash and loaded by nickel oxide (Ni 2 O 3 ). The resulted composite was characterized using X-ray diffraction, scanning electron microscope, and UV-vis spectrophotometer. The role of MCM-48 as catalyst support in enhancing the photocatalytic properties of nickel oxide was evaluated through the photocatalytic degradation of Congo red dye under visible light source. MCM-48 as catalyst support for Ni 2 O 3 shows considerable enhancement in the adsorption capacity by 17% and 29% higher than the adsorption capacity of MCM-48 and Ni 2 O 3 , respectively. Additionally, the photocatalytic degradation percentage increased by about 64% relative to the degradation percentage using Ni 2 O 3 as a single component. The adsorption mechanism of MCM-48/Ni 2 O 3 is chemisorption process of multilayer form. The using of MCM-48 as catalyst support for Ni 2 O 3 enhanced the adsorption capacity and the photocatalytic degradation through increasing the surface area and prevents the nickel oxide particles from agglomeration. This was done through fixing nickel oxide particles throughout the porous structure which providing more exposed active adsorption sites and active photocatalyst sites for the incident photons. Based on the obtained results, supporting of nickel oxide particles onto MCM-48 are promising active centers for the degradation of Congo red dye molecules. Copyright © 2017 Elsevier Ltd. All rights reserved.
Hydrothermal stability of silica, hybrid silica and Zr-doped hybrid silica membranes

NARCIS (Netherlands)

ten Hove, Marcel; Luiten-Olieman, Mieke W.J.; Huiskes, Cindy; Nijmeijer, Arian; Winnubst, Louis

2017-01-01

Hybrid silica membranes have demonstrated to possess a remarkable hydrothermal stability in pervaporation and gas separation processes allowing them to be used in industrial applications. In several publications the hydrothermal stability of pure silica or that of hybrid silica membranes are
Fumed silica. Fumed silica

Energy Technology Data Exchange (ETDEWEB)

Sukawa, T.; Shirono, H. (Nippon Aerosil Co. Ltd., Tokyo (Japan))

1991-10-18

The fumed silica is explained in particulate superfineness, high purity, high dispersiveness and other remarkable characteristics, and wide application. The fumed silica, being presently produced, is 7 to 40nm in average primary particulate diameter and 50 to 380m{sup 2}/g in specific surface area. On the surface, there coexist hydrophilic silanol group (Si-OH) and hydrophobic siloxane group (Si-O-Si). There are many characteristics, mutually different between the fumed silica, made hydrophobic by the surface treatment, and untreated hydrophilic silica. The treated silica, if added to the liquid product, serves as agent to heighten the viscosity, prevent the sedimentation and disperse the particles. The highest effect is given to heighten the viscosity in a region of 4 to 9 in pH in water and alcohol. As filling agent to strengthen the elastomer and polymer, and powder product, it gives an effect to prevent the consolidation and improve the fluidity. As for its other applications, utilization is made of particulate superfineness, high purity, thermal insulation properties and adsorption characteristics. 2 to 3 patents are published for it as raw material of quartz glass. 38 refs., 16 figs., 4 tabs.
Study on concrete with partial replacement of cement by rice husk ash

Science.gov (United States)

Kaarthik Krishna, N.; Sandeep, S.; Mini, K. M.

2016-09-01

Increase in the demand of conventional construction materials and the need for providing a sustainable growth in the construction field has prompted the designers and developers to opt for ‘alternative materials’ feasible for use in construction. For this objective, the use of industrial waste products and agricultural byproducts are very constructive. These industrial wastes and agricultural by products such as Fly Ash, Rice Husk Ash, Silica Fume, and Slag can be replaced instead of cement because of their pozzolanic behavior, which otherwise requires large tract of lands for dumping. In the present investigation, Rice Husk Ash has been used as an admixture to cement in concrete and its properties has been studied. An attempt was also done to examine the strength and workability parameters of concrete. For normal concrete, mix design is done based on Indian Standard (IS) method and taking this as reference, mix design has been made for replacement of Rice Husk Ash. Four different replacement levels namely 5%, 10%, 15% and 20% are selected and studied with respect to the replacement method.
Transfer of gaseous iodine from atmosphere to rough rice, brown rice and polished rice

International Nuclear Information System (INIS)

Sumiya, Misako; Uchida, Shigeo; Muramatsu, Yasuyuki; Ohmomo, Yoichiro; Yamaguchi, Shuho; Obata, Hitoshi.

1987-01-01

Experiments were carried out in order to obtain information required for establishing transfer coefficients of gaseous iodine (I 2 ) to rough rice, brown rice and polished rice. The gaseous iodine deposited on young rice plants before the heading period was scarcely found in the rough rice harvested at the full ripe stage. The biological half life of iodine in hull, however, was much slower than that in leaves of 14 days. The translocation of iodine from leaves and stalks to rough rice was not clearly recognized. Therefore, it was deduced that iodine found in brown rice mainly should originate from that deposited on the hull. The distribution ratios of iodine between rough rice and brown rice, and between brown rice and polished rice were 100:4 and 100:30 on 100 grains basis, respectively. If average normalized deposition velocity (V d(m) ) or derived deposition velocity (V s ) are given, the transfer coefficients of gaseous iodine to rough rice (TF r ), brown rice (TF b ) and polished rice (TF p ) could be calculated. (author)
Mixing process influence on thermal and rheological properties of NBR/SiO2 from rice husk ash

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Ana Maria Furtado de Sousa

Full Text Available Abstract Silica was extracted from rice husk ash (RHA by a sequence of reactions to produce nanosilica. Two laboratory routes, co-coagulation and spray drying, were used to incorporate the nanosilica into the rubber matrix. Samples were characterized regarding filler incorporation efficiency, thermal stability, rheological behavior and morphology. Thermogravimetric analysis showed that spray-drying was the most efficient filler incorporation process and also the presence of silica increased the thermal resistance of the rubber compound when compared to the unfilled rubber. The rheological behavior showed that NBR filled with silica presented higher elastic torque (S’, storage modulus (G’ and complex viscosity (η* than unfilled rubber. The Payne effect was also observed for the composites produced by spray-drying. In addition, the thermal behavior and Payne effect results were supported by the comparison of morphology observed by FEG-SEM analysis.
Microbial, physical and chemical properties of irrigation water in rice fields of Southern Brazil

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MARIA HELENA L.R. RECHE

2016-03-01

Full Text Available ABSTRACT This paper presents the results of the statistical analysis of microbiological, physical and chemical parameters related to the quality of the water used in rice fields in Southern Brazil. Data were collected during three consecutive crop years, within structure of a comprehensive monitoring program. The indicators used were: potential hydrogen, electrical conductivity, turbidity, nitrogen, phosphorus, potassium, calcium, total and fecal coliforms. Principal Component and Discriminant Analysis showed consistent differences between the water irrigation and drainage, as the temporal variation demonstrated a clear reduction in the concentration of most of the variables analyzed. The pattern of this reduction is not the same in the two regions - that is, the importance of each of the different variables in the observed differentiation is modified in two locations. These results suggested that the variations in the water quality utilized for rice irrigation was influenced by certain specific aspects of each rice region in South Brazilian - such as anthropic action or soil/climate conditions in each hydrographic basin.
Synthesis of zeolite from rice husk ash waste of brick industries as hydrophobic adsorbent for fuel grade ethanol purification

Science.gov (United States)

Purnomo, A.; Alhanif, M.; Khotimah, C.; Zuhra, UA; Putri, BR; Kumoro, AC

2017-11-01

A lot of researchers have devoted on ethanol utilization as renewable energy to substitute petroleum based gasoline. When ethanol is being used as a new fuel candidate, it should have at least of 99.5% purity. Usually produced via sugar fermentation process, further purification of ethanol from other components in fermentation broth to obtain its fuel grade is a crucial step. The purpose of this research is to produce synthetic zeolite as hydrophobic adsorbent from rice husk ash for ethanol-water separation and to investigate the influence of weight, adsorption time and initial ethanol concentration on zeolite adsorption capacity. This research consisted of rice husk silica extraction, preparation of hydrophobic zeolite adsorbent, physical characterization using SEM, EDX and adsorption test for an ethanol-water solution. Zeolite with highest adsorption capacity was obtained with 15: 1 alumina silica composition. The best adsorption condition was achieved when 4-gram hydrophobic zeolite applied for adsorption of 100 mL of 10% (v/v) ethanol-water solution for 120 minutes, which resulted in ethanol with 98.93% (v/v) purity. The hydrophobic zeolite from rice husk ash is a potential candidate as an efficient adsorbent to purify raw ethanol into fuel grade ethanol. Implementation of this new adsorbent for ethanol production in commercial scale may reduce the energy consumption of that usually used for the distillation processes.
Catalytic esterification via silica immobilized p-phenylenediamine and dithiooxamide solid catalysts

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Thana Jaafar Al-Hasani

2017-02-01

Full Text Available The p-phenylenediamine (PDA and dithiooxamide (DTO were immobilized onto silica from rice husk ash (RHA using 3-chloropropyltriethoxyilane (CPTES to form a solid catalyst denoted as RHAPDA and RHADTO, respectively. BET measurements of the catalysts showed the surface area to be 145 and 9.7 m2 g−1 with an average pore diameter of 9.8 and 10.9 nm, respectively. The catalytic performance of RHAPDA and RHADTO was tested in the esterification of ethyl alcohol with acetic acid. A conversion of 48% and 69% was achieved, respectively with 100% selectivity toward ethyl acetate.
Polyethyleneimine-loaded bimodal porous silica as low-cost and high-capacity sorbent for CO{sub 2} capture

Energy Technology Data Exchange (ETDEWEB)

Witoon, Thongthai, E-mail: fengttwi@ku.ac.th [National Center of Excellence for Petroleum, Petrochemicals and Advance Material, Department of Chemical Engineering, Faculty of Engineering, Kasetsart University, Bangkok 10900 (Thailand); Center for Advanced Studies in Nanotechnology and Its Applications in Chemical Food and Agricultural Industries, Kasetsart University, Bangkok 10900 (Thailand)

2012-11-15

In this work, bimodal (meso-macro) porous silicas with different mesopore diameters synthesized by using rice husk ash as a low-cost silica source and chitosan as a natural template were used as a polyethyleneimine (PEI) support for CO{sub 2} capture. Unimodal porous silica supports with equivalent mesopore diameters to bimodal porous silica supports have been prepared for purpose of comparison. Effects of different PEI contents (10, 20, 30, 40 and 50 wt%) on CO{sub 2} sorption capacity have been systematically investigated. The porous silica supports and the PEI-loaded porous silica supports were characterized by N{sub 2}-sorption analysis, scanning electron microscopy, Fourier transform infrared spectroscopy and thermal gravimetric analysis. CO{sub 2} sorption measurements of all PEI-loaded porous silica supports were performed at different adsorption temperatures (60, 75, 85, 90, 95 and 105 Degree-Sign C). At low PEI contents (10-20 wt%), the CO{sub 2} sorption of all adsorbents was found to decrease as a function of adsorption temperature, which was a characteristic of a thermodynamically-controlled regime. A transition from the thermodynamically-controlled regime to a kinetically-controlled regime was found when the PEI content was increased up to 30 wt% for PEI-loaded unimodal porous silicas and 40 wt% for PEI-loaded bimodal porous silicas. At high PEI contents (40-50 wt%), the CO{sub 2} capturing efficiency of the PEI-loaded bimodal porous silicas was found to be considerably greater than that of the PEI-loaded unimodal porous silicas, indicating that most of the amine groups of PEI molecules loaded on the unimodal porous silica supports was useless, and thus the appeared macroporosity of the bimodal porous silica supports could provide a higher effective amine density to adsorb CO{sub 2}. Highlights: Black-Right-Pointing-Pointer PEI-impregnated bimodal porous silica as low-cost sorbent for CO{sub 2} capture. Black-Right-Pointing-Pointer Macropores enhances
Effects of slag-based silicon fertilizer on rice growth and brown-spot resistance.

Science.gov (United States)

Ning, Dongfeng; Song, Alin; Fan, Fenliang; Li, Zhaojun; Liang, Yongchao

2014-01-01

It is well documented that slag-based silicon fertilizers have beneficial effects on the growth and disease resistance of rice. However, their effects vary greatly with sources of slag and are closely related to availability of silicon (Si) in these materials. To date, few researches have been done to compare the differences in plant performance and disease resistance between different slag-based silicon fertilizers applied at the same rate of plant-available Si. In the present study both steel and iron slags were chosen to investigate their effects on rice growth and disease resistance under greenhouse conditions. Both scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to examine the effects of slags on ultrastructural changes in leaves of rice naturally infected by Bipolaris oryaze, the causal agent of brown spot. The results showed that both slag-based Si fertilizers tested significantly increased rice growth and yield, but decreased brown spot incidence, with steel slag showing a stronger effect than iron slag. The results of SEM analysis showed that application of slags led to more pronounced cell silicification in rice leaves, more silica cells, and more pronounced and larger papilla as well. The results of TEM analysis showed that mesophyll cells of slag-untreated rice leaf were disorganized, with colonization of the fungus (Bipolaris oryzae), including chloroplast degradation and cell wall alterations. The application of slag maintained mesophyll cells relatively intact and increased the thickness of silicon layer. It can be concluded that applying slag-based fertilizer to Si-deficient paddy soil is necessary for improving both rice productivity and brown spot resistance. The immobile silicon deposited in host cell walls and papillae sites is the first physical barrier for fungal penetration, while the soluble Si in the cytoplasm enhances physiological or induced resistance to fungal colonization.
Climate Change Implications to Irrigated Rice Production in Southern Brazil: A Modelling Approach

Science.gov (United States)

Dos Santos, Thiago

Rice is one of the staple foods for more than three billion people worldwide. When cultivated under irrigated conditions (i.e. lowland rice), rice is one of the most intensive water consumer crops globally. Therefore, representation of rice growth should be integrated into the latest land surface models to allow studies on food security and to ensure that accurate simulations of the bidirectional feedbacks between the land surface and atmosphere take place. In this study, I present a new process-based model for rice fields that includes rice growth and rice irrigation as modules within the Agro-IBIS dynamic agro-ecosystem model. The model includes a series of equations, agricultural management parameters and an irrigation scheme that are specifically tailored for rice crops. The model was evaluated against leaf area index and biomass observations, obtained for one growing season in Rio Grande do Sul state (southern Brazil), and in Los Banos, Philippines. The model accurately captured the temporal dynamics of leaf area index in both the Brazilian and the Philippine sites, and predicted end-of-season biomass with an error of between -9.5% and 11.3% depending on the location and the plant organ. Rice phenology is predicted by the model based on experimentally-derived growth rates, and was evaluated by comparing simulated and observed durations of the four growth phases considered by the model. Agro-IBIS showed a tendency to overestimate the duration of the growth stages between 3% and 16%, but underestimated by 8% the duration of the panicle formation phase in one growing season. The new irrigation model is based on the water balance at the surface and applies irrigation in order to keep the water layer at the paddy field always in the optimum level. A set of climate projections from global climate models under two emission scenarios, and excluding and considering CO2 fertilizations effects, was used to drive the updated Agro-IBIS to estimate the effects of climate
Potencial de cruzamento natural entre o arroz transgênico resistente ao herbicida glufosinato de amônio e o arroz daninho Outcrossing potential of glufosinate-resistant rice to red rice

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J.A. Noldin

2002-08-01

Full Text Available A utilização de cultivares de arroz irrigado resistentes a herbicidas não-seletivos, como o glufosinato de amônio, pode se constituir numa alternativa de controle de arroz daninho em lavouras de arroz irrigado. O objetivo deste trabalho foi avaliar a taxa e o sentido do cruzamento natural entre plantas de uma linhagem modificada geneticamente para resistência ao herbicida glufosinato de amônio (arroz GM e ao arroz daninho. A taxa de cruzamento natural entre o arroz GM como receptor feminino e o arroz daninho como doador de pólen foi de 0,22 e 0,02%, respectivamente para os ecótipos de arroz daninho com glumas de cor palha e com glumas pretas. No caso inverso, quando o arroz daninho foi o receptor feminino e o arroz GM o doador de pólen, a taxa de cruzamento foi de 0,26 e 0,14%, para o arroz daninho com glumas palha e com glumas pretas, respectivamente. Os resultados deste estudo evidenciaram que ocorreu cruzamento natural entre o arroz GM e o arroz daninho em percentuais que variaram de 0,14 e 0,48%, respectivamente para o arroz preto e para o arroz vermelho. A fim de minimizar a possibilidade de hibridação, medidas de controle eficientes devem ser adotadas no sentido de prevenir a coincidência de floração das plantas de arroz daninho com a das plantas de arroz GM cultivado.The broad spectrum non-selective herbicide ammonium glufosinate, combined with genetically modified glufosinate-resistant rice cultivars (GM rice, may comprise a rice weed control system for red rice and other weeds that infest Brazilian rice fields. The objective of this study was to evaluate the potential for outcrossing and gene flow of GM rice to red rice. Natural outcrossing between adjacent field plots (1 m x 1 m was measured during the 1999/2000 production season in Brazil. The outcrossing rate of the GM rice as the female parent to red rice, as the pollen donor, was 0.22% for strawhull and 0.02% for the blackhull red rice, respectively. In the reciprocal
Zeolite and wollastonite synthesis from rice hull ash

International Nuclear Information System (INIS)

Fernandes, Alberto de Andrade

2006-01-01

Rice hull ash (RHA) is a industry scrap rich in amorphous silica. A simple and low-energy cost method for the extraction of this silica was researched. A low level of impurity and high reactivity material was produced, which is appropriate for the synthesis of zeolites and wollastonite (CaSiO 3 ). The synthetic zeolites has not similar structures in nature, and they have been more and more valued in the market due to their purity and efficiency in specific applications like ion exchange, molecular sieve and catalysis areas. High purity wollastonite has many applications in manufacturing and agriculture. The mineral wollastonite can be formed in nature in different ways; it is generally accepted two forming processes, both encompassing limestone metamorphism (heat and pressure). In this work, a new process for the synthesis of zeolites and wollastonite from RHA colloidal silica was developed. Moreover, the process is aimed at lower energy costs, fewer stages and fewer reactants consume. In this work, zeolite A used in detergent and zeolite ZSM-5, employed in the petrochemical industry due to its high selectivity in catalytic reactions and its high thermo and acid stability, were synthesized. The first step of the wollastonite synthesis was studied, with the purpose of obtaining calcium hydrosilicate. Eleven different hydrosilicates occur in the system Ca(OH) 2 -SiO 2 -H 2 O, in the second step it was annealed to form the wollastonite phase. (author)
A preliminary study on the reduction of limonite ore by using rice husk as a reducing agent

Science.gov (United States)

Maksum, Ahmad; Husein, Michael Kelvin E.; Permana, Sulaksana; Rustandi, Andi; Wahyuadi Soedarsono, Johny

2018-03-01

The abundant of rice husk in Indonesia has encouraged researchers to study the feasibility of rice husk for substituting material that is more expensive or dangerous. In previous study, silica with a purity of 99.9% has been obtained from rice husk with calcinations process. Nevertheless, the gases resulting from the process were not used and left useless. Therefore, in this study, those gases derived from rice husk calcinations process were used as reducing agents during the ferronickel (Fe-Ni) production through a direct reduction process. The objective of this study was to investigate the effect of the amount of rice husk in the pellets on the increase of nickel content in the limonite reduction process. The limonite ore were crushed to the size of less than 150 mesh using disc-mill, and then were mixed with rice husk powder (10, 20, 30 in wt % mass) before being pelletized using bentonite as a binder. The resulted pellets were roasted at 500°C for 60 minutes and then quenched in water media. After drying process, the reduction process of 40g pellets was conducted at 1000°C for 90 minutes with 20g rice husk in furnace. The effects of additional rice husk on the direct reduction of limonite ore pellets were qualitatively analyzed by using X-ray powder diffraction (XRD) and quantitatively by Atomic absorption spectroscopy (AAS). Both analysis results showed that the reduction process followed the reaction scheme: Fe2O3→Fe3O4→FeO and NiO phase was detected in the sample with 20% rice husk addition. The optimum concentration of Ni 1.23% was obtained for 20% rice husk addition.
Diet Quality and Adequacy of Nutrients in Preschool Children: Should Rice Fortified with Micronutrients Be Included in School Meals?

Science.gov (United States)

Della Lucia, Ceres M.; Rodrigues, Kellen Cristina C.; Rodrigues, Vivian Cristina C.; Santos, Laura Luiza M.; Cardoso, Leandro M.; Martino, Hércia S. D.; Franceschini, Sylvia C. C.; Pinheiro-Sant’Ana, Helena Maria

2016-01-01

Feeding is indicative of the nutritional status of children, however micronutrient deficiency is common in this age group. We evaluated the impact of inclusion of rice (Ultra Rice® (UR®)) fortified with iron, zinc, thiamin and folic acid on laboratory measurements and the nutrient intake of children. Ninety-nine preschoolers (2–6 years; 42.6% male) from two preschools participated, one of which received UR® added to polished rice as part of school meals (test preschool) and the other received only polished rice (control preschool). Biochemical evaluations were performed before and after four months of intervention. Feeding was assessed by direct weighing of food, complemented by 24-h recalls, and the diet was assessed by the Healthy Eating Index (HEI) adapted to the Brazilian reality. The fortified rice improved the levels of zinc (p < 0.001), thiamine (p < 0.001), folic acid (p = 0.003), mean corpuscular hemoglobin (p < 0.001) and mean corpuscular hemoglobin concentration (p < 0.001). The inadequacy percentages of thiamine, folic acid and iron were lower among preschoolers from the test preschool. This study demonstrated the effectiveness of using UR® on laboratory measurements of children. The inadequate intake of thiamine, folic acid and iron was also reduced, making the fortified rice an interesting strategy in school feeding programs. PMID:27187464
Enhancement of Catalytic Performance of MCM-41 Synthesized with Rice Husk Silica by Addition of Titanium Dioxide for Photodegradation of Alachlor

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Surachai Artkla

2009-01-01

Full Text Available Photocatalytic degradation of alachlor, a herbicide, in water on both bare TiO2 and TiO2 supported on mesoporous material, marked as TiO2/RH-MCM-41 were studied. The RH-MCM-41 support was synthesized from rice husk silica and other reagents by hydrothermal method. The required amount of titanium precursor (TiO2 P25 Degussa to give 10-60% was mixed with RH-MCM-41 and calcined at 300 °C for 6 h. The catalytic activities of TiO2 and TiO2/RH-MCM-41 for alachlor degradation were performed under UV radiation with wavelength of 300 nm. The ratio of catalyst weight to volume of alachlor solution was 1 g/L and all products were characterized by high performance liquid chromatograph. The reaction equilibrium was established in 30 min. in deionized water without adjusting the solution pH. The TiO2/RH-MCM-41 could adsorb alachlor more than the bare TiO2 (namely, 17% vs. 5% and the photocatalytic activity of alachlor degration on all TiO2/RH-MCM-41s was higher than that on the bare TiO2. By comparison per weight of TiO2, the 10%TiO2/RH-MCM-41 gave the highest alachlor conversion of 100% after 20 min. while 1% bare TiO2 showed conversion of 95%.
Analysis of nitrogen and carbon tetrachloride adsorption isotherms and pore size distribution for siliceous MCM-41 synthesized from rice husk silica

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Siriluk Chiarakorn

2004-02-01

Full Text Available RH-MCM-41 particles were synthesized using sodium silicate prepared from rice husk as a silica source and hexadecyltrimethylammonium bromide (CTAB as a surfactant. The molar compositions were 1.0SiO2: 1.1NaOH: 0.13CTAB: 0.12H2O. This material was used for adsorption isotherm studies of carbon tetrachloride (CT at 25 oC using a magnetically coupled microbalance, and compared with adsorption isotherms using nitrogen at 77 K. The CT isotherms were classified as reversible Type V isotherms, and the nitrogen adsorption isotherm was Type IVc. Capillary condensation was found in a very narrow pressure range, indicating the presence of nearly uniform pores in the RH-MCM-41 particles, which agrees very well with TEM results. The surface area estimated by using the BET method was (800 ± 8 m2 g-1. Pore size distributions (PSD of nitrogen and CT adsorption isotherms for a series of MCM-41 were calculated by using method recommended by Naono and Hakuman (1997. The pore size distributions from the nitrogen isotherm using the BJH and Naono methods showed quite narrow pore diameter distributions, centered around 27 and 29 Å, respectively. Similarly, the peak pore diameters calculated from CT isotherms using the BJH and Naono methods were 24 and 28 Å. It was found that the PSDs analyzed by the BJH method were underestimated compared to that from Naono method.
Studying of Nano SiO2 Preparation from Rice Husk Ash by Using High Gravity Reaction Precipitation Technology

International Nuclear Information System (INIS)

Nguyen Thanh Chung; Tran Ngoc Ha; Hoang Van Duc

2013-01-01

A novel method (High-gravity reactive precipitation - HGRP) was developed to prepare nano-SiO 2 from rice husk ash using gas-liquid reaction system. The precipitated silica produced by our proposed method had average size of 20 nm with narrow size distribution and purity of SiO 2 was approximately 99.2%. The principles of the method as well as experimental conditions were also described. (author)
Silica Nephropathy

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N Ghahramani

2010-06-01

Full Text Available Occupational exposure to heavy metals, organic solvents and silica is associated with a variety of renal manifestations. Improved understanding of occupational renal disease provides insight into environmental renal disease, improving knowledge of disease pathogenesis. Silica (SiO2 is an abundant mineral found in sand, rock, and soil. Workers exposed to silica include sandblasters, miners, quarry workers, masons, ceramic workers and glass manufacturers. New cases of silicosis per year have been estimated in the US to be 3600–7300. Exposure to silica has been associated with tubulointerstitial disease, immune-mediated multisystem disease, chronic kidney disease and end-stage renal disease. A rare syndrome of painful, nodular skin lesions has been described in dialysis patients with excessive levels of silicon. Balkan endemic nephropathy is postulated to be due to chronic intoxication with drinking water polluted by silicates released during soil erosion. The mechanism of silica nephrotoxicity is thought to be through direct nephrotoxicity, as well as silica-induced autoimmune diseases such as scleroderma and systemic lupus erythematosus. The renal histopathology varies from focal to crescentic and necrotizing glomerulonephritis with aneurysm formation suggestive of polyarteritis nodosa. The treatment for silica nephrotoxicity is non-specific and depends on the mechanism and stage of the disease. It is quite clear that further research is needed, particularly to elucidate the pathogenesis of silica nephropathy. Considering the importance of diagnosing exposure-related renal disease at early stages, it is imperative to obtain a thorough occupational history in all patients with renal disease, with particular emphasis on exposure to silica, heavy metals, and solvents.

Some Durability Characteristics of Micro Silica and Nano Silica Contained Concrete

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Mohammed Salah Nasr

2016-12-01

Full Text Available This paper aims to investigate the influence of replacement of cement with nano and micro silica admixtures on some durability properties of concrete such as water absorption, chloride content and pH tests. Three replacement ratios (5%,10%,15% of micro silica and four replacement proportions (0.5%,1.5%,3%,5% for nano silica were used in this study. Two exposure conditions were considered for chloride content test: wetting-drying and full immersing exposure in 6% of chloride ions solution, NaCl type. Results showed that mixes of %5 micro silica and 5% nano silica had lower content of chloride (about 0.19% and 0.18% for wetting-drying and full immersing exposure respectively. For water absorption test, all mixes incorporated micro and nano silica, except for %5 micro silica mix, showed lower absorption than control mixes. For pH test, results indicated that the adding of nano and micro silica didn’t affect adversely the alkalinity of concrete.
Rice husk ash – A valuable reinforcement for high density polyethylene

International Nuclear Information System (INIS)

Ayswarya, E.P.; Vidya Francis, K.F.; Renju, V.S.; Thachil, Eby Thomas

2012-01-01

Highlights: ► RHA is formed from the incineration of rice husk. ► RHA is mainly a mixture of silica with various metallic compounds. ► RHA is a valuable reinforcing material for HDPE. ► RHA can be incorporated into HDPE by the melt blending process. ► The best mechanical properties are observed at 1.5% RHA and 15% compatibilizer. -- Abstract: This paper presents the results of a study on the use of rice husk ash (RHA) for property modification of high density polyethylene (HDPE). Rice husk is a waste product of the rice processing industry. It is used widely as a fuel which results in large quantities of RHA. Here, the characterization of RHA has been done with the help of X-ray diffraction (XRD), Inductively Coupled Plasma Atomic Emission Spectroscopy (ICPAES), light scattering based particle size analysis, Fourier transform infrared spectroscopy (FTIR) and Scanning Electron Microscope (SEM). Most reports suggest that RHA when blended directly with polymers without polar groups does not improve the properties of the polymer substantially. In this study RHA is blended with HDPE in the presence of a compatibilizer. The compatibilized HDPE-RHA blend has a tensile strength about 18% higher than that of virgin HDPE. The elongation-at-break is also higher for the compatibilized blend. TGA studies reveal that uncompatibilized as well as compatibilized HDPE-RHA composites have excellent thermal stability. The results prove that RHA is a valuable reinforcing material for HDPE and the environmental pollution arising from RHA can be eliminated in a profitable way by this technique.
Preparation and characterization of clay bonded high strength silica refractory by utilizing agriculture waste

International Nuclear Information System (INIS)

Bhardwaj, A.; Hossain, S.K.S.; Majh, M.R.

2017-01-01

Clay bonded silica refractory was prepared by utilizing agriculture waste called rice husk ash (RHA) and refractory grog. Various samples were prepared with different compositions based upon partial replacement of quartz by RHA. Rectangular samples were prepared by following semi dry process prior to pressing in a uniaxial hydraulic press and sintering at a temperature of 1200°C in air atmosphere. Various physical, mechanical and thermal characterizations were done like X-ray diffraction (XRD), scanning electron microscope (SEM), apparent porosity (AP), bulk density (BD), cold crushing strength (CCS), refractoriness and thermal conductivity measurement. The sample utilizing 30% of RHA was considered most optimum composition which produced cold crushing strength of 38MPa and thermal conductivity of 2.08W/mK at 800°C with a considerable good refractoriness. Enhancement in the mechanical as well as thermal properties may be considered as attributed to the amorphous silica which has reacted more easily and efficiently with other material surrounding giving rise to the densification and produced stable crystalline phase to the refractory material. These promising characteristics suggests that the RHA may lead to be used as a potential material for the preparation of clay bonded high strength silica refractories. [es
Nanostructured silicon nitride from wheat and rice husks

Energy Technology Data Exchange (ETDEWEB)

Qadri, S. B.; Rath, B. B.; Gorzkowski, E. P.; Wollmershauser, J. A.; Feng, C. R. [Materials Science and Component Technology Directorate, Naval Research Laboratory, Washington, D.C. 20375 (United States)

2016-04-07

Nanoparticles, submicron-diameter tubes, and rods of Si{sub 3}N{sub 4} were synthesized from the thermal treatment of wheat and rice husks at temperatures at and above 1300 °C in a nitrogen atmosphere. The whole pattern Rietveld analysis of the observed diffraction data from treatments at 1300 °C showed the formation of only hexagonal α-phase of Si{sub 3}N{sub 4} with an R-factor of 1%, whereas samples treated at 1400 °C and above showed both α- and β-phases with an R-factor of 2%. Transmission electron microscopy showed the presence of tubes, rods, and nanoparticles of Si{sub 3}N{sub 4}. In a two-step process, where pure SiC was produced first from rice or wheat husk in an argon atmosphere and subsequently treated in a nitrogen atmosphere at 1450 °C, a nanostructured composite material having α- and β-phases of Si{sub 3}N{sub 4} combined with cubic phase of SiC was formed. The thermodynamics of the formation of silicon nitride is discussed in terms of the solid state reaction between organic matter (silica content), which is inherently present in the wheat and rice husks, with the nitrogen from the furnace atmosphere. Nanostructures of silicon nitride formed by a single direct reaction or their composites with SiC formed in a two-step process of agricultural byproducts provide an uncomplicated sustainable synthesis route for silicon nitride used in mechanical, biotechnology, and electro-optic nanotechnology applications.
Isolation of campesteryl ferulate and epi-campesteryl ferulate, two components of γ-oryzanol from rice bran.

Science.gov (United States)

Bao, Yuhua; Yanase, Emiko; Nakatsuka, Shin-ichi

2013-01-01

Campesteryl ferulate (3a, 24R/α) and epi-campesteryl ferulate (3b, 24S/β), components of rice bran γ-oryzanol, were isolated by the preparative recycle HPLC system using a combination of ODS silica and cholester packed columns at over 99% purity. Their purities and structures of 3a and 3b thus obtained were confirmed by HPLC analysis and physical data (1H- and 13C-NMR, MS spectra, and X-ray crystallography).
Microporous silica membranes

DEFF Research Database (Denmark)

Boffa, Vittorio; Yue, Yuanzheng

2012-01-01

Hydrothermal stability is a crucial factor for the application of microporous silica-based membranes in industrial processes. Indeed, it is well established that steam exposure may cause densification and defect formation in microporous silica membranes, which are detrimental to both membrane...... permeability and selectivity. Numerous previous studies show that microporous transition metal doped-silica membranes are hydrothermally more stable than pure silica membranes, but less permeable. Here we present a quantitative study on the impact of type and concentration of transition metal ions...... on the microporous structure, stability and permeability of amorphous silica-based membranes, providing information on how to design chemical compositions and synthetic paths for the fabrication of silica-based membranes with a well accessible and highly stabile microporous structure....
Diet Quality and Adequacy of Nutrients in Preschool Children: Should Rice Fortified with Micronutrients Be Included in School Meals?

Directory of Open Access Journals (Sweden)

Ceres M. Della Lucia

2016-05-01

Full Text Available Feeding is indicative of the nutritional status of children, however micronutrient deficiency is common in this age group. We evaluated the impact of inclusion of rice (Ultra Rice® (UR® fortified with iron, zinc, thiamin and folic acid on laboratory measurements and the nutrient intake of children. Ninety-nine preschoolers (2–6 years; 42.6% male from two preschools participated, one of which received UR® added to polished rice as part of school meals (test preschool and the other received only polished rice (control preschool. Biochemical evaluations were performed before and after four months of intervention. Feeding was assessed by direct weighing of food, complemented by 24-h recalls, and the diet was assessed by the Healthy Eating Index (HEI adapted to the Brazilian reality. The fortified rice improved the levels of zinc (p < 0.001, thiamine (p < 0.001, folic acid (p = 0.003, mean corpuscular hemoglobin (p < 0.001 and mean corpuscular hemoglobin concentration (p < 0.001. The inadequacy percentages of thiamine, folic acid and iron were lower among preschoolers from the test preschool. This study demonstrated the effectiveness of using UR® on laboratory measurements of children. The inadequate intake of thiamine, folic acid and iron was also reduced, making the fortified rice an interesting strategy in school feeding programs.
The macro- and micro properties of cement pastes with silica-rich materials cured by wet-mixed steaming injection

International Nuclear Information System (INIS)

Wu, D.S.; Peng, Y.N.

2003-01-01

This research used cement pastes with a low water/blaine ratio (W/b=0.27). Rice husk ashes (RHA) burned at 700 and 850 deg. C, silica fume, silica sand (Ottawa standard sand), etc., were the added ingredients. Wet-mixed steam injection (WMSI) was at five different temperatures: 65, 80, 120, 150 and 180 deg. C. We investigated cement pastes with added silica-rich materials. For different WMSI temperatures and times, we explored the relations between compressive strength, hydration products, and pozzolanic reaction mechanism. From scanning electron microscopy (SEM) and EDS, we know that hydration products become very complicated, depending on the WMSI temperatures and times. It is difficult to determine the direct effects on the strength based on changes in the products. Experimental results, however, clearly showed that the compressive strength was worst for 80 deg. C and best for 180 deg. C. High-temperature WMSI is best with 4-h presteaming period and 8-h retention time. Curing in saturated limewater for 28 days did not increase the strength. The three types of silica-rich materials used in this research all participated in the reaction during high-temperature WMSI; they helped to increase the strength. Addition of Ottawa standard sand resulted in the best strength, followed by addition of RHA, while addition of silica fume was worse than the others. Specimens treated with high-temperature WMSI would swell slightly if they were placed in air. This was different from normal-temperature curing
Crystalline Silica Primer

Science.gov (United States)

,

1992-01-01

Crystalline silica is the scientific name for a group of minerals composed of silicon and oxygen. The term crystalline refers to the fact that the oxygen and silicon atoms are arranged in a threedimensional repeating pattern. This group of minerals has shaped human history since the beginning of civilization. From the sand used for making glass to the piezoelectric quartz crystals used in advanced communication systems, crystalline silica has been a part of our technological development. Crystalline silica's pervasiveness in our technology is matched only by its abundance in nature. It's found in samples from every geologic era and from every location around the globe. Scientists have known for decades that prolonged and excessive exposure to crystalline silica dust in mining environments can cause silicosis, a noncancerous lung disease. During the 1980's, studies were conducted that suggested that crystalline silica also was a carcinogen. As a result of these findings, crystalline silica has been regulated under the Occupational Safety and Health Administration's (OSHA) Hazard Communication Standard (HCS). Under HCS, OSHAregulated businesses that use materials containing 0.1% or more crystalline silica must follow Federal guidelines concerning hazard communication and worker training. Although the HCS does not require that samples be analyzed for crystalline silica, mineral suppliers or OSHAregulated
Broken rice kernels and the kinetics of rice hydration and texture during cooking.

Science.gov (United States)

Saleh, Mohammed; Meullenet, Jean-Francois

2013-05-01

During rice milling and processing, broken kernels are inevitably present, although to date it has been unclear as to how the presence of broken kernels affects rice hydration and cooked rice texture. Therefore, this work intended to study the effect of broken kernels in a rice sample on rice hydration and texture during cooking. Two medium-grain and two long-grain rice cultivars were harvested, dried and milled, and the broken kernels were separated from unbroken kernels. Broken rice kernels were subsequently combined with unbroken rice kernels forming treatments of 0, 40, 150, 350 or 1000 g kg(-1) broken kernels ratio. Rice samples were then cooked and the moisture content of the cooked rice, the moisture uptake rate, and rice hardness and stickiness were measured. As the amount of broken rice kernels increased, rice sample texture became increasingly softer (P hardness was negatively correlated to the percentage of broken kernels in rice samples. Differences in the proportions of broken rice in a milled rice sample play a major role in determining the texture properties of cooked rice. Variations in the moisture migration kinetics between broken and unbroken kernels caused faster hydration of the cores of broken rice kernels, with greater starch leach-out during cooking affecting the texture of the cooked rice. The texture of cooked rice can be controlled, to some extent, by varying the proportion of broken kernels in milled rice. © 2012 Society of Chemical Industry.
Results of an experimental campaign of monitoring of agricultural practice of field combustion of rice straw; Risultati di una campagna sperimentale di monitoraggio della pratica di combustione all`aperto della paglia di riso

Energy Technology Data Exchange (ETDEWEB)

Spezzano, P.; Cerea, E.; Massironi, L.; Nocente, M.; Olivetta, A. [ENEA, Centro Ricerche Saluggia, Vercelli (Italy). Dipt. Ambiente; Castellani, C. M.; De Zaiacomo, T. [ENEA, centro Ricerche ``Ezio Clementel``, Bologna (Italy). Dipt. Ambiente

1997-09-01

For the evaluation of environmental impact of agricultural practice of field combustion of rice straw following harvest an experimental campaign was performed in a field situated near Rive Vercellese (Vercelli, Italy) by burning the amount of rice straw in a 1.2 hectare piece of ground. Four sampling positions were operated, each one composed of a miniaturized impactor and a battery-powered pump, and an optical monitor was also used to measure aerosuspended aerosol concentration continuously. Experimental results show that after field combustion, resulting ash is depleted in cadmium, copper, lead and zinc while manganese and silica remaining almost quantitatively in the ash. Manganese and silica were the only components attributable to field combustion of rice straw in the atmospheric aerosol collected during this monitoring survey. Aerosuspended mass concentration values obtained by means of both optical measurements and gravimetric determinations are presented. Aerosol granulometric distribution, measured in the vicinity of the experimental field and the parameter values of the log-normal distribution obtained with experimental data are also indicated. Finally, a comparison is made between aerosol granulometric data and respirable fraction as defined by international standards.
Development of ultrafine and pure amorphous and crystalline new materials and their fabrication process

International Nuclear Information System (INIS)

Yang, Myung Seung; Kim, Y. E.; Kim, J. G.; Gu, J. H.; Yoon, N. K.; Seong, S. Y.; Ryu, S. E.; Lee, J. C.

1996-07-01

Based on an estimation of annual rice production of 5.2 Million tons, rice husks by-production reaches to 1.17 Million tons per year in Korea. distinguished to other corns, rice contains a lot of Si; 10 ∼ 20 % by weight in rice husks calculated as silica. The aim of this research project is to develop technologies for ceramic powders and materials utilizing the silica in rice husks called phytoliths. In this researches of the following subjects were performed; decomposition of the organic components, acid treatments, extraction of the organic matter, effect of gamma-ray irradiation on the acid treatment, plasma treatment, crystallization of silica powder, dispersion of amorphous silica powder, fabrication of ultrafine crystalline fibrous materials.. (author). 18 refs., 5 tabs., 55 figs
Investigating differences in light stable isotopes between Thai jasmine rice and Sungyod rice

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Kukusamude, C.; Kongsri, S.

2017-10-01

We report the differences in light stable isotopes between two kinds of Thai rice (Thai jasmine and Sungyod rice). Thai jasmine rice and Sungyod rice were cultivated in the northeast and the south of Thailand. Light isotopes including 13C, 15N and 18O of Thai jasmine rice and Sungyod rice samples were carried out using isotope ratio mass spectrometry (IRMS). Thai jasmine rice (Khao Dawk Mali 105) was cultivated from Thung Kula Rong Hai area, whereas Sungyod rice was cultivated from Phathalung province. Hypothesis testing of difference of each isotope between Thai jasmine rice and Sungyod rice was also studied. The study was the feasibility test whether the light stable isotopes can be the variables to identify Thai jasmine rice and Sungyod rice. The result shows that there was difference in the isotope patterns of Thai jasmine rice and Sungyod rice. Our results may provide the useful information in term of stable isotope profiles of Thai rice.
Extraction of rice bran oil from local rice husk

International Nuclear Information System (INIS)

Anwar, J.; Zaman, W.; Salman, M.; Jabeen, N.

2006-01-01

Rice Bran Oil is widely used in pharmaceutical, food and chemical industries due to its unique properties and high medicinal value. In the present work, extraction of rice bran oil from different samples of rice husk collected from local rice shellers by solvent extraction method has been studied. Experiments were conducted using a soxhelt apparatus, to extract rice bran oil using hexane, petroleum ether, ethanol and methanol as the solvents and the yields obtained under different conditions were compared. Batch extraction tests showed that the rate of extraction decreases with time and the solution approaches saturation at an exponential rate. (author)
Rice herbicide monitoring in two Brazilian rivers during the rice growing season Monitoramento de herbicidas em dois rios brasileiros durante o período de cultivo do arroz

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Enio Marchesan

2007-01-01

Full Text Available Irrigated rice production can involve environmental contamination with pesticides due to the proximity of the fields to rivers and to management problems. During three years (2000 to 2003 the rice herbicides clomazone, propanil and quinclorac were quantified in water during the rice growing season, in the Vacacaí and Vacacaí-Mirim Rivers, located in Rio Grande do Sul (RS State, Brazil. Water samples were taken at several locations in each river, selected by their importance in terms of rice drainage area. The samples were analyzed by HPLC-UV. At least one herbicide was detected in 41% of the samples from the Vacacaí River and 33% from the Vacacaí-Mirim River. The most frequent herbicide in both rivers and in each year was clomazone. The amount of herbicides in the river water was dependent on the rainfall regime. River water contamination by rice herbicides is probably caused by the rice water management used in the fields. The maintenance of flooded areas makes herbicides prone to contaminate the environment. To reduce the environmental contamination risk it is necessary to adopt measures to avoid overflow of flooded rice fields, keeping paddy water in the field for time enough to reduce the herbicide concentration before its release and enhancing the quality of the levees to reduce the probability of paddy rice overflow.No cultivo de arroz irrigado a possibilidade de contaminação dos mananciais hídricos é ampliada pelas características peculiares das áreas e do sistema de produção. Um estudo de monitoramento foi conduzido durante três anos (2000 a 2003, nos rios Vacacaí e Vacacaí-Mirim, localizados no Estado do Rio Grande do Sul, Brasil, buscando quantificar os herbicidas clomazone, propanil e quinclorac durante o período de cultivo do arroz. As amostras de água foram coletadas em vários locais em cada rio. Os locais de coleta foram selecionados pela importância em termos da captação da água de drenagem. As amostras foram
Late Cretaceous origin of the rice tribe provides evidence for early diversification in Poaceae.

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Prasad, V; Strömberg, C A E; Leaché, A D; Samant, B; Patnaik, R; Tang, L; Mohabey, D M; Ge, S; Sahni, A

2011-09-20

Rice and its relatives are a focal point in agricultural and evolutionary science, but a paucity of fossils has obscured their deep-time history. Previously described cuticles with silica bodies (phytoliths) from the Late Cretaceous period (67-65 Ma) of India indicate that, by the latest Cretaceous, the grass family (Poaceae) consisted of members of the modern subclades PACMAD (Panicoideae-Aristidoideae-Chloridoideae-Micrairoideae-Arundinoideae-Danthonioideae) and BEP (Bambusoideae-Ehrhartoideae-Pooideae), including a taxon with proposed affinities to Ehrhartoideae. Here we describe additional fossils and show that, based on phylogenetic analyses that combine molecular genetic data and epidermal and phytolith features across Poaceae, these can be assigned to the rice tribe, Oryzeae, of grass subfamily Ehrhartoideae. The new Oryzeae fossils suggest substantial diversification within Ehrhartoideae by the Late Cretaceous, pushing back the time of origin of Poaceae as a whole. These results, therefore, necessitate a re-evaluation of current models for grass evolution and palaeobiogeography.
RiceAtlas, a spatial database of global rice calendars and production.

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Laborte, Alice G; Gutierrez, Mary Anne; Balanza, Jane Girly; Saito, Kazuki; Zwart, Sander J; Boschetti, Mirco; Murty, M V R; Villano, Lorena; Aunario, Jorrel Khalil; Reinke, Russell; Koo, Jawoo; Hijmans, Robert J; Nelson, Andrew

2017-05-30

Knowing where, when, and how much rice is planted and harvested is crucial information for understanding the effects of policy, trade, and global and technological change on food security. We developed RiceAtlas, a spatial database on the seasonal distribution of the world's rice production. It consists of data on rice planting and harvesting dates by growing season and estimates of monthly production for all rice-producing countries. Sources used for planting and harvesting dates include global and regional databases, national publications, online reports, and expert knowledge. Monthly production data were estimated based on annual or seasonal production statistics, and planting and harvesting dates. RiceAtlas has 2,725 spatial units. Compared with available global crop calendars, RiceAtlas is nearly ten times more spatially detailed and has nearly seven times more spatial units, with at least two seasons of calendar data, making RiceAtlas the most comprehensive and detailed spatial database on rice calendar and production.
Silica coated ionic liquid templated mesoporous silica nanoparticles ...

African Journals Online (AJOL)

A series of long chain pyridinium based ionic liquids 1-tetradecylpyridinium bromide, 1-hexadecylpyridinium bromide and 1-1-octadecylpyridinium bromide were used as templates to prepare silica coated mesoporous silica nanoparticles via condensation method under basic condition. The effects of alkyl chain length on ...
Transgene Flow from Glufosinate-Resistant Rice to Improved and Weedy Rice in China

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Yong-liang LU

2014-09-01

Full Text Available The development of transgenic rice with novel traits in China can increase rice productivity, but transgene flow to improved or weedy rice has become a major concern. We aimed to evaluate the potential maximum frequencies of transgene flow from glufosinate-resistant rice to improved rice cultivars and weedy rice. Treatments were arranged in randomized complete blocks with three replicates. Experiments were conducted between 2009 and 2010 at the Center for Environmental Safety Supervision and Inspection for Genetically Modified Plants, China National Rice Research Institute, Hangzhou, China. Glufosinate-resistant japonica rice 99-1 was the pollen donor. The pollen recipients were two inbred japonica rice (Chunjiang 016 and Xiushui 09, two inbred indica rice (Zhongzu 14 and Zhongzao 22, two indica hybrid rice (Zhongzheyou 1 and Guodao 1, and one weedy indica rice (Taizhou weedy rice. The offspring of recipients were planted in the field and sprayed with a commercial dose of glufosinate. Leaf tissues of survivors were analyzed by polymerase chain reaction to detect the presence of the transgene. The frequency of gene flow ranged from 0 to 0.488%. In 2009, the order of gene flow frequency was as follows: weedy rice > Chunjiang 016 > Xiushui 09 and Zhongzu 14 > Guodao 1, Zhongzheyou 1 and Zhongzao 22. Gene flow frequencies were generally higher in 2009 than in 2010, but did not differ significantly among rice materials. Gene flow frequency was the highest in weedy rice followed by the inbred japonica rice. The risk of gene flow differed significantly between years and year-to-year variance could mask risk differences among pollen recipients. Gene flow was generally lesser in taller pollen recipients than in shorter ones, but plant height only accounted for about 30% of variation in gene flow. When flowering synchrony was maximized, as in this study, low frequencies of gene flow occurred from herbicide-resistant japonica rice to other cultivars and
Effects of water management on arsenic and cadmium speciation and accumulation in an upland rice cultivar.

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Hu, Pengjie; Ouyang, Younan; Wu, Longhua; Shen, Libo; Luo, Yongming; Christie, Peter

2015-01-01

Pot and field experiments were conducted to investigate the effects of water regimes on the speciation and accumulation of arsenic (As) and cadmium (Cd) in Brazilian upland rice growing in soils polluted with both As and Cd. In the pot experiment constant and intermittent flooding treatments gave 3-16 times higher As concentrations in soil solution than did aerobic conditions but Cd showed the opposite trend. Compared to arsenate, there were more marked changes in the arsenite concentrations in the soil solution as water management shifted, and therefore arsenite concentrations dominated the As speciation and bioavailability in the soil. In the field experiment As concentrations in the rice grains increased from 0.14 to 0.21 mg/kg while Cd concentrations decreased from 0.21 to 0.02 mg/kg with increasing irrigation ranging from aerobic to constantly flooding conditions. Among the various water regimes the conventional irrigation treatment produced the highest rice grain yield of 6.29 tons/ha. The As speciation analysis reveals that the accumulation of dimethylarsinic acid (from 11.3% to 61.7%) made a greater contribution to the increase in total As in brown rice in the intermittent and constant flooding treatments compared to the intermittent-aerobic treatment. Thus, water management exerted opposite effects on Cd and As speciation and bioavailability in the soil and consequently on their accumulation in the upland rice. Special care is required when irrigation regime methods are employed to mitigate the accumulation of metal(loid)s in the grain of rice grown in soils polluted with both As and Cd. Copyright © 2014. Published by Elsevier B.V.

Effects of pressure and temperature on pore structure of ceramic synthesized from rice husk: A small angle neutron scattering investigation

Energy Technology Data Exchange (ETDEWEB)

Raut Dessai, R., E-mail: reshooin@yahoo.com [Department of Physics, Goa University, Taleigao Plateau, Goa 403 206 (India); Desa, J.A.E. [Department of Physics, Goa University, Taleigao Plateau, Goa 403 206 (India); Sen, D.; Mazumder, S. [Solid State Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)

2013-07-05

Highlights: ► A porous ceramic has been prepared from silica obtained from rice husk. ► The ceramic has a hierarchical pore structure from micrometric to nano-metric. ► Small Angle Neutron Scattering data indicate nano-pore connectivity to micro-pores. ► Pore morphology can be tuned by compaction pressure and sintering temperature. -- Abstract: Ceramic powder has been synthesized from rice husk as the source of silica. In order to probe the evolution of its hierarchical mesoscopic and microscopic porous structure, the ceramic powder was compacted at different pressures and was sintered at different temperatures. A glassy ceramic to crystalline transition under thermal treatment (up to 1000 °C) was revealed by X-ray diffraction. Existence of pores in two widely separated length scales was indicated by small angle neutron scattering with the smaller ones having mass fractal arrangement. Although no significant change in small pore structure under thermal effect was indicated, a significant modification of the same has been revealed by small angle neutron scattering at different compaction pressures. Connectivity between the pores was ascertained from scattering experiments on the ceramic compact impregnated with heavy water. Scanning electron microscopy shows the microstructure to undergo appreciable coalescence of micrometric ceramic particles for sintering temperature and pressure changes.
Application of mercapto-silica polymerized high internal phase emulsions for the solid-phase extraction and preconcentration of trace lead(II).

Science.gov (United States)

Su, Rihui; Ruan, Guihua; Chen, Zhengyi; Du, Fuyou; Li, Jianping

2015-12-01

A new class of solid-phase extraction column prepared with grafted mercapto-silica polymerized high internal phase emulsion particles was used for the preconcentration of trace lead. First, mercapto-silica polymerized high internal phase emulsion particles were synthesized by using high internal phase emulsion polymerization and carefully assembled in a polyethylene syringe column. The influences of various parameters including adsorption pH value, adsorption and desorption solvents, flow rate of the adsorption and desorption procedure were optimized, respectively, and the suitable uploading sample volumes, adsorption capacity, and reusability of solid phase extraction column were also investigated. Under the optimum conditions, Pb(2+) could be preconcentrated quantitatively over a wide pH range (2.0-5.0). In the presence of foreign ions, such as Na(+) , K(+) , Ca(2+) , Zn(2+) , Mg(2+) , Cu(2+) , Fe(2+) , Cd(2+) , Cl(-) and NO3 (-) , Pb(2+) could be recovered successfully. The prepared solid-phase extraction column performed with high stability and desirable durability, which allowed more than 100 replicate extractions without measurable changes of performance. The feasibility of the developed method was further validated by the extraction of Pb(2+) in rice samples. At three spiked levels of 40.0, 200 and 800 μg/kg, the average recoveries for Pb(2+) in rice samples ranged from 87.3 to 105.2%. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Preparation and characterization of clay bonded high strength silica refractory by utilizing agriculture waste

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Aman Bhardwaj

2017-11-01

Full Text Available Clay bonded silica refractory was prepared by utilizing agriculture waste called rice husk ash (RHA and refractory grog. Various samples were prepared with different compositions based upon partial replacement of quartz by RHA. Rectangular samples were prepared by following semi dry process prior to pressing in a uniaxial hydraulic press and sintering at a temperature of 1200 °C in air atmosphere. Various physical, mechanical and thermal characterizations were done like X-ray diffraction (XRD, scanning electron microscope (SEM, apparent porosity (AP, bulk density (BD, cold crushing strength (CCS, refractoriness and thermal conductivity measurement. The sample utilizing 30% of RHA was considered most optimum composition which produced cold crushing strength of 38 MPa and thermal conductivity of 2.08 W/m K at 800 °C with a considerable good refractoriness. Enhancement in the mechanical as well as thermal properties may be considered as attributed to the amorphous silica which has reacted more easily and efficiently with other material surrounding giving rise to the densification and produced stable crystalline phase to the refractory material. These promising characteristics suggests that the RHA may lead to be used as a potential material for the preparation of clay bonded high strength silica refractories. Resumen: Se preparó sílice refractaria unida a arcilla con residuos agrícolas conocidos como ceniza de cascarilla de arroz (rice husk ash [RHA] y grog refractario. Se prepararon varias muestras con diferentes composiciones basadas en la sustitución parcial de cuarzo por RHA. Las muestras rectangulares se prepararon siguiendo un proceso semiseco antes de prensarlas en una prensa hidráulica uniaxial y sinterizarlas a una temperatura de 1.200 °C en atmósfera de aire. Se realizaron diversas caracterizaciones físicas, mecánicas y térmicas, como la difracción de rayos X, el microscopio electrónico de barrido, la porosidad
A Comparative Evaluation of Dried Activated Sludge and Mixed Dried Activated Sudge with Rice Husk silica to Remove Hydrogen Sulfide

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Seyed Mahmoud Mehdinia

2013-03-01

Full Text Available The aim of this study was to investigate the effectiveness of dried activated sludge (DAS and mixed dried activated sludge with rice husk silica (DAS & RHS for removal of hydrogen sulfide (H2S. Two laboratory-scale filter columns (packed one litter were operated. Both systems were operated under different conditions of two parameters, namely different inlet gas concentrations and different inlet flow rates. The DAS & RHS packed filter showed more than 99.96% removal efficiency (RE with empty bed residence time (EBRT of 45 to 90 s and 300 mg/L inlet concentration of H2S. However, the RE decreased to 96.87% with the EBRT of 30 s. In the same condition, the DAS packed filter showed 99.37% RE. Nonetheless, the RE was shown to have dropped to 82.09% with the EBRT of 30 s. The maximum elimination capacity (EC was obtained in the DAS & RHS packed filter up to 52.32 g/m3h, with the RE of 96.87% and H2S mass loading rate of 54 g/m3h. The maximum EC in the DAS packed filter was obtained up to 44.33 g/m3h with the RE of 82.09% and the H2S mass loading rate of 54 g/m3h. After 53 days of operating time and 54 g/m3h of loading rates, the maximum pressure drop reached to 3.0 and 8.0 (mm H2O for the DAS & RHS packed and DAS packed filters, respectively. Based on the findings of this study, the DAS & RHS could be considered as a more suitable packing material to remove H2S.
Characteristic of New Solid-Phase Extraction Sorbent: Activated Carbon Prepared from Rice Husks under Base Treated Condition

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Afrida Kurnia Putri

2012-10-01

Full Text Available A characterization of activated carbon (ACs prepared from rice husks (RHs under base treated condition as a new sorbent for solid-phase extraction (SPE to extract 4-nonylphenol isomers (4-NPs in water samples has been done. The ACs prepared from RHs usually exhibits low specific surface area due to its high ash content, but in case of its application for SPE, there are other factors need to be considered, such as the existence of functional groups inside the sorbent, that can enhance interaction of non-polar sorbent with analyte in the water matrices. In this case, silanol groups from ash content may affect the extraction efficiency for 4-NPs. The ACs made from RHs were chemically impregnated with ZnCl2 and carbonized at 800oC. To investigate the role of silica, three types of ACs were prepared, i.e., untreated ACs (AC–Si, contain silica, base treated ACs (AC–B–Si, remain some silica inside, and ACs made by base treated RHs (AC–B, no silica, the surface area obtained from these treatments were 1352 m2/g, 1666 m2/g, and 1712m2/g respectively. ACs made by base treatment has the highest surface area (related to BET, which indicat that silica removal process promotes the formation of open pore system on ACs and enhances the surface area of ACs. However, extraction efficiency measured by GC-MS in SPE process showed the reversal trends (i.e., AC–Si= 32.08%, AC–B–Si= 82.63%, AC–B=51.78%, among them the AC–B–Si sorbent reveal the best performance in SPE process. It is indicated that although silica usually exhibits low specific surface area, but control presence of silica as a polar functional group has a positive influence in the interaction between non-polar sorbent and 4-NPs.
Rice production in relation to soil quality under different rice-based cropping systems

Science.gov (United States)

Tran Ba, Linh; Sleutel, Steven; Nguyen Van, Qui; Thi, Guong Vo; Le Van, Khoa; Cornelis, Wim

2016-04-01

Soil quality of shallow paddy soils may be improved by introducing upland crops and thus a more diverse crop cultivation pattern. Yet, the causal relationship between crop performance and enhanced soil traits in rice-upland crop rotations remains elusive. The objectives of this study were to (i) find correlations among soil properties under different rice-upland crop systems and link selected soil properties to rice growth and yield, (ii) present appropriate values of soil parameters for sustainable rice productivity in heavy clay soil, (iii) evaluate the effect of rotating rice with upland crops on rice yield and economic benefit in a long-term experiment. A rice-upland crop rotational field experiment in the Vietnamese Mekong delta was conducted for 10 years using a randomized complete block design with four treatments and four replications. Treatments were: (i) rice-rice-rice (control - conventional system as farmers' practice), (ii) rice-maize-rice, (iii) rice-mung bean-rice, and (iv) rice-mung bean-maize. Soil and plant sampling were performed after harvest of the rice crop at the end of the final winter-spring cropping season (i.e. year 10). Results show differences in rice growth and yield, and economic benefit as an effect of the crop rotation system. These differences were linked with changes in bulk density, soil porosity, soil aggregate stability index, soil penetration resistance, soil macro-porosity, soil organic carbon, acid hydrolysable soil C and soil nutrient elements, especially at soil depth of 20-30 cm. This is evidenced by the strong correlation (P < 0.01) between rice plant parameters, rice yield and soil properties such as bulk density, porosity, penetration resistance, soil organic carbon and Chydrolysable. It turned out that good rice root growth and rice yield corresponded to bulk density values lower than 1.3 Mg m-3, soil porosity higher than 50%, penetration resistance below 1.0 MPa, and soil organic carbon above 25 g kg-1. The optimal
RPAN: rice pan-genome browser for ∼3000 rice genomes.

Science.gov (United States)

Sun, Chen; Hu, Zhiqiang; Zheng, Tianqing; Lu, Kuangchen; Zhao, Yue; Wang, Wensheng; Shi, Jianxin; Wang, Chunchao; Lu, Jinyuan; Zhang, Dabing; Li, Zhikang; Wei, Chaochun

2017-01-25

A pan-genome is the union of the gene sets of all the individuals of a clade or a species and it provides a new dimension of genome complexity with the presence/absence variations (PAVs) of genes among these genomes. With the progress of sequencing technologies, pan-genome study is becoming affordable for eukaryotes with large-sized genomes. The Asian cultivated rice, Oryza sativa L., is one of the major food sources for the world and a model organism in plant biology. Recently, the 3000 Rice Genome Project (3K RGP) sequenced more than 3000 rice genomes with a mean sequencing depth of 14.3×, which provided a tremendous resource for rice research. In this paper, we present a genome browser, Rice Pan-genome Browser (RPAN), as a tool to search and visualize the rice pan-genome derived from 3K RGP. RPAN contains a database of the basic information of 3010 rice accessions, including genomic sequences, gene annotations, PAV information and gene expression data of the rice pan-genome. At least 12 000 novel genes absent in the reference genome were included. RPAN also provides multiple search and visualization functions. RPAN can be a rich resource for rice biology and rice breeding. It is available at http://cgm.sjtu.edu.cn/3kricedb/ or http://www.rmbreeding.cn/pan3k. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.
Analysis of rice purchase decision on rice consumer in Bandung city

Science.gov (United States)

Kusno, K.; Imannurdin, A.; Syamsiyah, N.; Djuwendah, E.

2018-03-01

This study was conducted at three kinds of purchase location which were traditional market, rice kiosk, and supermarket in Bandung City, with survey data of 108 respondents which were selected by systematic random sampling. The aim of this study is to (1) identify consumer characteristics, (2) identify which atribute is considered by consumer in buying rice, and (3) analyze the relationship between purchase decision and income class. Data were analyzed by descriptive analysis and Chi Square test. The results showed most consumers in the traditional market were middle-educated and lower middle-income, at the rice kiosk, the consumer were generally middle-educated and middle-income, and in the supermarkets, the majority were high-educated and upper middle-income consumers. “Kepulenan” be the first priority of most consumers, but for the lower-middle class, the main priority was price. Thus, in case of scarcity and rice price increase, the government should immediately arrange market operations which targeting to lower-middle class consumers. There was a significant relationship between (1) the quality of rice consumed, (2) the frequency of rice purchase per month, and (3) attitudes toward rice price increase; each with the income class. Although the price of rice increase, consumers of middle and upper-middle were remain loyal to the quality of rice they consumed. This indicates rice market in Bandung city is an ideal market for premium rice so that traders and producers are expected to maintain the quality of rice, such as keep using superior seeds and applying good cultivation based on Good Agricultural Practice (GAP) rules.
Improvement of physical and chemical properties of concrete with brazilian silica rice husk (SRH La mejora de propiedades físicas y químicas de hormigón con silice de cáscara de arroz (SRH brasileña

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Fernanda Giannotti da Silva

2008-04-01

Full Text Available The use of industrial and agricultural waste substitutions for Portland cement has greatly contributed to sustainable development practices. The increase in cement demand will be met by the use of supplementary cementing materials, in order to minimize the clinker consumption. In this study, the effects of silica extracted from rice husk (SRH as a partial replacement of cement in concretes with low water/binder are reported. The properties investigated include compressive strength, splitting tensile strength, water absorption by immersion, water absorption by capillarity and resistance to chloride ion penetration. The research indicates that SRH is an effective mineral addition for designing durable concrete presenting an optimal performance when the replacement ratio of Portland cement is around 10%El uso de desechos industriales y agrícolas como segmento en la producción de cemento Portland ha contribuido de manera importante en la práctica de desarrollo sustentable. El aumento en la demanda de cemento coincide con el uso de materiales aglomerantes suplementarios para minimizar el consumo de clinker. En este estudio, se informan los efectos de la sustitución parcial de cemento Portland por sílice extraído de la cascara de arroz (SRH en hormigones con baja relación agua/materiales cementicios. Las propiedades investigadas incluyen resistencia a la compresión, resistencia a la tracción, absorción de agua por inmersión, absorción de agua por capilaridad y resistencia a la penetración de iones de cloruro. La investigación indica que SRH es una adición mineral eficaz para el diseño de hormigones durables que presenta una actuación óptima cuando la proporción del reemplazo de cemento de Portland está alrededor de 10%
PhosphoRice: a meta-predictor of rice-specific phosphorylation sites

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Que Shufu

2012-02-01

Full Text Available Abstract Background As a result of the growing body of protein phosphorylation sites data, the number of phosphoprotein databases is constantly increasing, and dozens of tools are available for predicting protein phosphorylation sites to achieve fast automatic results. However, none of the existing tools has been developed to predict protein phosphorylation sites in rice. Results In this paper, the phosphorylation site predictors, NetPhos 2.0, NetPhosK, Kinasephos, Scansite, Disphos and Predphosphos, were integrated to construct meta-predictors of rice-specific phosphorylation sites using several methods, including unweighted voting, unreduced weighted voting, reduced unweighted voting and weighted voting strategies. PhosphoRice, the meta-predictor produced by using weighted voting strategy with parameters selected by restricted grid search and conditional random search, performed the best at predicting phosphorylation sites in rice. Its Matthew's Correlation Coefficient (MCC and Accuracy (ACC reached to 0.474 and 73.8%, respectively. Compared to the best individual element predictor (Disphos_default, PhosphoRice archieved a significant increase in MCC of 0.071 (P Conclusions PhosphoRice is a powerful tool for predicting unidentified phosphorylation sites in rice. Compared to the existing methods, we found that our tool showed greater robustness in ACC and MCC. PhosphoRice is available to the public at http://bioinformatics.fafu.edu.cn/PhosphoRice.
Removal of Ni(II), Zn(II) and Pb(II) ions from single metal aqueous solution using rice husk-based activated carbon

Energy Technology Data Exchange (ETDEWEB)

Taha, Mohd F., E-mail: faisalt@petronas.com.my; Shaharun, Maizatul S. [Fundamental and Applied Sciences Department, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750, Perak Darul Ridzuan (Malaysia); Shuib, Anis Suhaila, E-mail: anisuha@petronas.com.my; Borhan, Azry [Chemical Engineering Department, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750, Perak Darul Ridzuan (Malaysia)

2014-10-24

An attempt was made to investigate the potential of rice husk-based activated carbon as an alternative low-cost adsorbent for the removal of Ni(II), Zn(II) and Pb(II) ions from single aqueous solution. Rice husk-based activated carbon was prepared via treatment of rice husk with NaOH followed by the carbonization process at 400°C for 2 hours. Three samples, i.e. raw rice husk, rice husk treated with NaOH and rice husk-based activated carbon, were analyzed for their morphological characteristics using field-emission scanning electron microscope/energy dispersive X-ray (FESEM/EDX). These samples were also analyzed for their carbon, hydrogen, nitrogen, oxygen and silica contents using CHN elemental analyzer and FESEM/EDX. The porous properties of rice husk-based activated carbon were determined by Brunauer-Emmett-Teller (BET) surface area analyzer, and its surface area and pore volume were 255 m{sup 2}/g and 0.17 cm{sup 2}/g, respectively. The adsorption studies for the removal of Ni(II), Zn(II) and Pb(II) ions from single metal aqueous solution were carried out at a fixed initial concentration of metal ion (150 ppm) with variation amount of adsorbent (rice husk-based activated carbon) as a function of varied contact time at room temperature. The concentration of each metal ion was analyzed using atomic absorption spectrophotometer (AAS). The results obtained from adsorption studies indicate the potential of rice husk as an economically promising precursor for the preparation of activated carbon for removal of Ni(II), Zn(II) and Pb(II) ions from single aqueous solution. Isotherm and kinetic model analyses suggested that the experimental data of adsorption studies fitted well with Langmuir, Freundlich and second-order kinetic models.
The effect of silica toward polymer membrane for water separation process

Science.gov (United States)

Jamalludin, Mohd Riduan; Rosli, M. U.; Ishak, Muhammad Ikman; Khor, C. Y.; Shahrin, Suhaimi; Ismail, Ras Izzati; Lailina N., M.; Leng Y., L.; Jahidi, H.

2017-09-01

The aim of this present work was to investigate the effect of different percentage rice husk silica (RHS) particles composition towards polymer mixed matrix membrane microstructure and performance in water separation process. The polymer membranes were prepared by a phase inversion method using polysulfone (PSf), N-methyl-2-pyrrolidone (NMP) as solvent, distilled water as non-solvent and fixed RHS at 400°C as an additive. The microstructures of PSf/PEG/RHS sample were characterized by performing scanning electron microscope (SEM). The performance was measured by using pure water flux and humic acid for the rejection test. The analyzed result of SEM analysis revealed that the addition of RHS obviously improved the microstructure of the membrane especially at the top and sub layer at the range of 1 until 3 wt. %. This was proven by the pure water flux (PWF) value measured from 114.47 LMH to 154.04 LMH and rejection from value 83% to 96% at this specified range substantially higher than the mixed matrix membrane with synthetic silica. In fact, the presence of RHS particles not only improved the properties and performance of membrane but also possess biodegradable properties which can minimize the pollution and provide a membrane green technology system.
Rice microstructure

Science.gov (United States)

An understanding of plant structure is desirable to obtain a clear idea of the overall impact of a crop. A mature rice plant consists of leafy components (left in the field post-harvest) and paddy rice (collected). The rice plant is supported by a hollow stem (culm) with leaf sheaths attached to nod...
[Nitrogen cycling in rice-duck mutual ecosystem during double cropping rice growth season].

Science.gov (United States)

Zhang, Fan; Chen, Yuan-Quan; Sui, Peng; Gao, Wang-Sheng

2012-01-01

Raising duck in paddy rice field is an evolution of Chinese traditional agriculture. In May-October 2010, a field experiment was conducted in a double cropping rice region of Hunan Province, South-central China to study the nitrogen (N) cycling in rice-duck mutual ecosystem during early rice and late rice growth periods, taking a conventional paddy rice field as the control. Input-output analysis method was adopted. The N output in the early rice-duck mutual ecosystem was 239.5 kg x hm(-2), in which, 12.77 kg x hm(-2) were from ducks, and the N output in the late rice-duck mutual ecosystem was 338.7 kg x hm(-2), in which, 23.35 kg x hm(-2) were from ducks. At the present N input level, there existed soil N deficit during the growth seasons of both early rice and late rice. The N input from duck sub-system was mainly from the feed N, and the cycling rate of the duck feces N recycled within the system was 2.5% during early rice growth season and 3.5% during late rice growth season. After late rice harvested, the soil N sequestration was 178.6 kg x hm(-2).
Silica-Immobilized Enzyme Reactors

Science.gov (United States)

2007-08-01

Silica-IMERs 14 implicated in neurological disorders such as Schizophrenia and Parkinson’s disease.[86] Drug discovery for targets that can alter the...primarily the activation of prodrugs and proantibiotics for cancer treatments or antibiotic therapy , respectively.[87] Nitrobenzene nitroreductase was...BuChE) Monolith disks* Packed Silica Biosilica Epoxide- Silica Silica-gel Enzyme Human AChE Human AChE Human AChE Equine BuChE Human
MASS BALANCE OF SILICA IN STRAW FROM THE PERSPECTIVE OF SILICA REDUCTION IN STRAW PULP

Directory of Open Access Journals (Sweden)

Celil Atik,

2012-06-01

Full Text Available The high silica content of wheat straw is an important limiting factor for straw pulping. High silica content complicates processing and black liquor recovery, wears out factory installations, and lowers paper quality. Each section of wheat straw has different cells and chemical compositions and thus different silica content. In this work, the silica content of balled straw samples were examined according to their physical components, including internodes, nodes, leaves (sheath and blade, rachis, grain, other plant bodies, and other plant spikes. Mass distribution of silica was determined by a dry ashing method. Half (50.90% of the silica comes from leaves, and its mechanical separation will reduce the silica content in wheat straw pulp significantly. Destroying silica bodies by sonication will increase the strength properties of straw pulp.
Liquid Phase Deposition of Silica on the Hexagonally Close-Packed Monolayer of Silica Spheres

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Seo Young Yoon

2013-01-01

Full Text Available Liquid phase deposition is a method used for the nonelectrochemical production of polycrystalline ceramic films at low temperatures, most commonly silicon dioxide films. Herein, we report that silica spheres are organized in a hexagonal close-packed array using a patterned substrate. On this monolayer of silica spheres, we could fabricate new nanostructures in which deposition and etching compete through a modified LPD reaction. In the early stage, silica spheres began to undergo etching, and then, silica bridges between the silica spheres appeared by the local deposition reaction. Finally, the silica spheres and bridges disappeared completely. We propose the mechanism for the formation of nanostructure.
The association between socioeconomic characteristics and consumption of food items among Brazilian industry workers.

Science.gov (United States)

Vinholes, Daniele B; Melo, Ione M F; Machado, Carlos Alberto; de Castro Chaves, Hilton; Fuchs, Flavio D; Fuchs, Sandra C

2012-01-01

Dietary pattern plays a causative role in the rising of noncommunicable diseases. The SESI (Serviço Social da Indústria) study was designed to evaluate risk factors for noncommunicable diseases. We aimed to describe food items consumed by Brazilian workers and to assess their association with socioeconomic status. Cross-sectional study was carried out among Brazilian industrial workers, selected by multistage sampling, from 157 companies. Interviews were conducted at the work place using standardized forms. 4818 workers were interviewed, aged 35.4 ± 10.7 years, 76.5% were men. The workers had an average of 8.7 ± 4.1 years of schooling and 25.4 ± 4.1 kg/m² of BMI. Men and individuals with less than high school education were less likely to consume dairy products, fruits, and vegetables daily, even after control for confounding factors. Men consumed rice and beans daily more often than women. In comparison to workers aged 50-76 years, those under 30 years old consumed less fruits and green leafy vegetables daily. The food items consumed by Brazilian workers show that there are insufficient consumption according to the guidelines of healthy foods, particularly of dairy products, vegetables, and fruits.
Effects of Extraction Methods on Phytochemicals of Rice Bran Oils Produced from Colored Rice.

Science.gov (United States)

Mingyai, Sukanya; Srikaeo, Khongsak; Kettawan, Aikkarach; Singanusong, Riantong; Nakagawa, Kiyotaka; Kimura, Fumiko; Ito, Junya

2018-02-01

Rice bran oil (RBO) especially from colored rice is rich in phytochemicals and has become popular in food, cosmetic, nutraceutical and pharmaceutical applications owing to its offering health benefits. This study determined the contents of phytochemicals including oryzanols, phytosterols, tocopherols (Toc) and tocotrienols (T3) in RBOs extracted using different methods namely cold-press extraction (CPE), solvent extraction (SE) and supercritical CO 2 extraction (SC-CO 2 ). Two colored rice, Red Jasmine rice (RJM, red rice) and Hom-nin rice (HN, black rice), were studied in comparison with the popular Thai fragrant rice Khao Dawk Mali 105 (KDML 105, white rice). RBOs were found to be the rich source of oryzanols, phytosterols, Toc and T3. Rice varieties had a greater effect on the phytochemicals concentrations than extraction methods. HN rice showed the significantly highest concentration of all phytochemicals, followed by RJM and KDML 105 rice, indicating that colored rice contained high concentration of phytochemicals in the oil than non-colored rice. The RBO samples extracted by the CPE method had a greater concentration of the phytochemicals than those extracted by the SC-CO 2 and SE methods, respectively. In terms of phytochemical contents, HN rice extracted using CPE method was found to be the best.
Performance at high temperature of alkali-activated slag pastes produced with silica fume and rice husk ash based activators

Directory of Open Access Journals (Sweden)

Bernal, S. A.

2015-06-01

Full Text Available This study assessed the mechanical properties, and structural changes induced by high temperature exposure, of alkali-silicate activated slag cements produced with sodium silicates derived from silica fume (SF and rice husk ash (RHA. Similar reaction products were identified, independent of the type of silicate used, but with subtle differences in the composition of the C-S-H gels, leading to different strength losses after elevated temperature exposure. Cements produced with the alternative activators developed higher compressive strengths than those produced with commercial silicate. All samples retained strengths of more than 50 MPa after exposure to 600 °C, however, after exposure to 800 °C only the specimens produced with the RHA-based activator retained measurable strength. This study elucidated that silicate-activated slag binders, either activated with commercial silicate solutions or with sodium silicates based on SF or RHA, are stable up to 600 °C.Este estudio evaluó las propiedades mecánicas, y cambios estructurales inducidos por exposición a temperaturas elevadas, de cementos de escoria activada alcalinamente producidos con silicatos sódicos derivados de humo de sílice (SF y ceniza de cascarilla de arroz (RHA. Se identificaron productos de reacción similares, independiente del tipo de silicato utilizado, pero con diferencias menores en la composición de las geles C-S-H, lo cual indujo diferentes pérdidas de resistencia posterior a exposición a temperaturas elevadas. Los cementantes producidos con los activadores alternativos desarrollaron resistencias a la compresión más altas que aquellos producidos con silicato comercial. Todas las muestras retuvieron resistencias de más de 50 MPa posterior a la exposición a 600 °C, sin embargo, posterior a la exposición a 800 °C únicamente muestras producidas con activadores de RHA retuvieron resistencias medibles. Este estudio elucidó que cementantes de escoria activada con

Grafting of polymer onto silica surface in the presence of γ-ray irradiated silica

International Nuclear Information System (INIS)

Tsuchida, A.; Yokoyama, R.; Takami, M.; Chen, J.; Ohta, M.; Tsubokawa, N.

2002-01-01

Complete text of publication follows. We have reported the graft polymerization of vinyl monomers initiated by surface radicals formed by the decomposition of azo and peroxide groups previously introduced onto the surface. In addition, the grafting of polymers onto carbon black has been reported by the reaction of polymer radicals with the surface. On the other hand, it is well known that the relatively stable radicals are generated on the surface by the γ-ray irradiation. In this paper, the grafting of polystyrene onto silica surface during the thermal polymerization of styrene in the presence of γ-ray irradiated silica, grafting mechanism and thermal stability of grafted polymer will be discussed. The grafting of polymers onto silica surface by irradiation of polymer-adsorbed silica was also investigated. Silica obtained from Mitsubishi Chemical Co., Japan was used after pulverization: the particle size was 0.037-0.088 mm. Irradiation was performed in Cs-137 source at room temperature. The silica was irradiated at 50 Gy with dose rate of 3.463 Gy/min. Into a polymerization tube, styrene and irradiated silica was charged and the polymerization was carried out under argon under stirring. The percentage of polystyrene grafting was determined from weight loss when polystyrene-grafted silica was heated at 600 deg C by a thermal analyzer. Untreated silica did not affect the thermal polymerization of styrene. On the contrary, the thermal polymerization of styrene was remarkably retarded in the presence of the irradiated silica at 60 deg C. Similar tendency was reported during the polymerization of vinyl monomers in the presence of carbon black. In the initial stage of the polymerization in the presence of the irradiated silica below 50 deg C, the polymerization was accelerated. During the polymerization in the presence of irradiated silica, polystyrene was grafted onto the surface: the percentage of grafting was 5-11%. The amount of polystyrene grafted onto silica
DETERMINATION OF SPATIAL INTEGRATION AND SUBSTITUTION OF FOREIGN RICE FOR LOCAL RICE IN GHANA

Directory of Open Access Journals (Sweden)

Philip Kofi ADOM

2014-11-01

Full Text Available This study tested for spatial integration in the rice market and the substitution of imported rice for local rice in Ghana. It is established that the markets for domestic imported rice are well-integrated, but not complete. The imperfect spatial integration of domestic foreign rice markets implies that the market provides opportunities for arbitrage. Price leadership roles are found to be determined by the kind of sub-inter-regional-trade network defined. However, in all, the Accra market emerged as a dominant market leader in the domestic foreign rice market. There is evidence of significant regional substitution of foreign rice for local rice in the long run, but the result is mixed in the short run. The result that local rice is not a perfect substitute for imported rice implies that price disincentive measures such as increasing the import tariffs on foreign rice will only produce a mild effect on increasing the producer price faced by local rice farmers, but aggravate the burden on households’ budget.
[Effects of fish on field resource utilization and rice growth in rice-fish coculture].

Science.gov (United States)

Zhang, Jian; Hu, Liang Liang; Ren, Wei Zheng; Guo, Liang; Wu, Min Fang; Tang, Jian Jun; Chen, Xin

2017-01-01

Rice field can provide habitat for fish and other aquatic animals. Rice-fish coculture can increase rice yield and simultaneously reduce the use of chemicals through reducing rice pest occurrence and nutrient complementary use. However, how fish uses food sources (e.g. phytoplankton, weeds, duckweed, macro-algal and snail) from rice field, and whether the nutrients releasing from those food sources due to fish transforming can improve rice growth are still unknown. Here, we conducted two field experiments to address these questions. One was to investigate the pattern of fish activity in the field using the method of video recording. The other was to examine the utilization of field resources by fish using stable isotope technology. Rice growth and rice yield were also exa-mined. Results showed that fish tended to be more active and significantly expanded the activity range in the rice-fish coculture compared to fish monoculture (fish not living together with rice plants). The contributions of 3 potential aquatic organisms (duckweed, phytoplankton and snail) to fish dietary were 22.7%, 34.8% and 30.0% respectively under rice-fish coculture without feed. Under the treatment with feed, however, the contributions of these 3 aquatic organisms to the fish die-tary were 8.9%, 5.9% and 1.6% respectively. The feed contribution was 71.0%. Rice-fish coculture significantly increased the nitrogen concentration in rice leaves, prolonged tillering stage by 10-12 days and increased rice spike rate and yield. The results suggested that raising fish in paddy field may transform the nutrients contained in field resources to bioavailable for rice plants through fish feeding activity, which can improve rice growth and rice yield.
Hydrothermal stability of microporous silica and niobia-silica membranes

NARCIS (Netherlands)

Boffa, V.; Blank, David H.A.; ten Elshof, Johan E.

2008-01-01

The hydrothermal stability of microporous niobia–silica membranes was investigated and compared with silica membranes. The membranes were exposed to hydrothermal conditions at 150 and 200 °C for 70 h. The change of pore structure before and after exposure to steam was probed by single-gas permeation
Serpentinization processes: Influence of silica

Science.gov (United States)

Huang, R.; Sun, W.; Ding, X.; Song, M.; Zhan, W.

2016-12-01

Serpentinization systems are highly enriched in molecular hydrogen (H2) and hydrocarbons (e.g. methane, ethane and propane). The production of hydrocarbons results from reactions between H2 and oxidized carbon (carbon dioxide and carbon monoxide), which possibly contribute to climate changes during early history of the Earth. However, the influence of silica on the production of H2 and hydrocarbons was poorly constrained. We performed experiments at 311-500 °C and 3.0 kbar using mechanical mixtures of silica and olivine in ratios ranging from 0 to 40%. Molecular hydrogen (H2), methane, ethane and propane were formed, which were analyzed by gas chromatography. It was found that silica largely decreased H2 production. Without any silica, olivine serpentinization produced 94.5 mmol/kg H2 after 20 days of reaction time. By contrast, with the presence of 20% silica, H2 concentrations decreased largely, 8.5 mmol/kg. However, the influence of silica on the production of hydrocarbons is negligible. Moreover, with the addition of 20%-40% silica, the major hydrous minerals are talc, which was quantified according to an established standard curve calibrated by infrared spectroscopy analyses. It shows that silica greatly enhances olivine hydration, especially at 500 °C. Without any addition of silica, reaction extents were serpentinization at 500 °C and 3.0 kbar. By contrast, with the presence of 50% silica, olivine was completely transformed to talc within 9 days. This study indicates that silica impedes the oxidation of ferrous iron into ferric iron, and that rates of olivine hydration in natural geological settings are much faster with silica supply.
Interfacial interaction between the epoxidized natural rubber and silica in natural rubber/silica composites

Science.gov (United States)

Xu, Tiwen; Jia, Zhixin; Luo, Yuanfang; Jia, Demin; Peng, Zheng

2015-02-01

The epoxidized natural rubber (ENR) as an interfacial modifier was used to improve the mechanical and dynamical mechanical properties of NR/silica composites. In order to reveal the interaction mechanism between ENR and silica, the ENR/Silica model compound was prepared by using an open mill and the interfacial interaction of ENR with silica was investigated by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), X-ray diffraction (XRD) and stress-strain testing. The results indicated that the ring-opening reaction occurs between the epoxy groups of ENR chains and Si-OH groups on the silica surfaces and the covalent bonds are formed between two phases, which can improve the dispersion of silica in the rubber matrix and enhance the interfacial combination between rubber and silica. The ring-opening reaction occurs not only in vulcanization process but also in mixing process, meanwhile, the latter seems to be more important due to the simultaneous effects of mechanical force and temperature.
Effects of White Rice, Brown Rice and Germinated Brown Rice on Antioxidant Status of Type 2 Diabetic Rats

OpenAIRE

Imam, Mustapha Umar; Musa, Siti Nor Asma; Azmi, Nur Hanisah; Ismail, Maznah

2012-01-01

Oxidative stress is implicated in the pathogenesis of diabetic complications, and can be increased by diet like white rice (WR). Though brown rice (BR) and germinated brown rice (GBR) have high antioxidant potentials as a result of their bioactive compounds, reports of their effects on oxidative stress-related conditions such as type 2 diabetes are lacking. We hypothesized therefore that if BR and GBR were to improve antioxidant status, they would be better for rice consuming populations inst...
Interfacial interaction between the epoxidized natural rubber and silica in natural rubber/silica composites

Energy Technology Data Exchange (ETDEWEB)

Xu, Tiwen [College of Materials Science and Engineering, South China University of Technology, Guangzhou 510640 (China); Jia, Zhixin, E-mail: zxjia@scut.edu.cn [College of Materials Science and Engineering, South China University of Technology, Guangzhou 510640 (China); Luo, Yuanfang; Jia, Demin [College of Materials Science and Engineering, South China University of Technology, Guangzhou 510640 (China); Peng, Zheng [Agricultural Product Processing Research Institute, Chinese Academy of Tropical Agriculture Sciences, Zhanjiang 524001 (China)

2015-02-15

Highlights: • Substantiate the ring open reaction between Si-OH of silica and epoxy groups of ENR. • ENR can act as a bridge between NR and silica to enhance the interfacial interaction. • As a modifier, ENR gets the potential to be used in the tread of green tire for improving the wet skid resistance apparently. - Abstract: The epoxidized natural rubber (ENR) as an interfacial modifier was used to improve the mechanical and dynamical mechanical properties of NR/silica composites. In order to reveal the interaction mechanism between ENR and silica, the ENR/Silica model compound was prepared by using an open mill and the interfacial interaction of ENR with silica was investigated by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), X-ray diffraction (XRD) and stress–strain testing. The results indicated that the ring-opening reaction occurs between the epoxy groups of ENR chains and Si-OH groups on the silica surfaces and the covalent bonds are formed between two phases, which can improve the dispersion of silica in the rubber matrix and enhance the interfacial combination between rubber and silica. The ring-opening reaction occurs not only in vulcanization process but also in mixing process, meanwhile, the latter seems to be more important due to the simultaneous effects of mechanical force and temperature.
Mutant-inducing effect of γ-ray irradiation for hybrid rice F1 derived from cross of black glutinous rice x wild rice

International Nuclear Information System (INIS)

Mao Dezhi; Tang Yilan

1998-01-01

The hybrid rice F 1 plant derived from the back crossing of glutinous rice x wild rice was irradiated with γ-ray. The result of investigation to the induced mutant showed that through the selection and backcross, a black glutinous rice strain with the short stem, cold tolerance and high yield was developed. The analysis of the ability of heredity variance showed that the selection was effective for the husk colour, black glutinous and black Indica rice, but ineffective for the white Indica rice and seed setting
Australian wild rice reveals pre-domestication origin of polymorphism deserts in rice genome.

Science.gov (United States)

Krishnan S, Gopala; Waters, Daniel L E; Henry, Robert J

2014-01-01

Rice is a major source of human food with a predominantly Asian production base. Domestication involved selection of traits that are desirable for agriculture and to human consumers. Wild relatives of crop plants are a source of useful variation which is of immense value for crop improvement. Australian wild rices have been isolated from the impacts of domestication in Asia and represents a source of novel diversity for global rice improvement. Oryza rufipogon is a perennial wild progenitor of cultivated rice. Oryza meridionalis is a related annual species in Australia. We have examined the sequence of the genomes of AA genome wild rices from Australia that are close relatives of cultivated rice through whole genome re-sequencing. Assembly of the resequencing data to the O. sativa ssp. japonica cv. Nipponbare shows that Australian wild rices possess 2.5 times more single nucleotide polymorphisms than in the Asian wild rice and cultivated O. sativa ssp. indica. Analysis of the genome of domesticated rice reveals regions of low diversity that show very little variation (polymorphism deserts). Both the perennial and annual wild rice from Australia show a high degree of conservation of sequence with that found in cultivated rice in the same 4.58 Mbp region on chromosome 5, which suggests that some of the 'polymorphism deserts' in this and other parts of the rice genome may have originated prior to domestication due to natural selection. Analysis of genes in the 'polymorphism deserts' indicates that this selection may have been due to biotic or abiotic stress in the environment of early rice relatives. Despite having closely related sequences in these genome regions, the Australian wild populations represent an invaluable source of diversity supporting rice food security.
Australian wild rice reveals pre-domestication origin of polymorphism deserts in rice genome.

Directory of Open Access Journals (Sweden)

Gopala Krishnan S

Full Text Available BACKGROUND: Rice is a major source of human food with a predominantly Asian production base. Domestication involved selection of traits that are desirable for agriculture and to human consumers. Wild relatives of crop plants are a source of useful variation which is of immense value for crop improvement. Australian wild rices have been isolated from the impacts of domestication in Asia and represents a source of novel diversity for global rice improvement. Oryza rufipogon is a perennial wild progenitor of cultivated rice. Oryza meridionalis is a related annual species in Australia. RESULTS: We have examined the sequence of the genomes of AA genome wild rices from Australia that are close relatives of cultivated rice through whole genome re-sequencing. Assembly of the resequencing data to the O. sativa ssp. japonica cv. Nipponbare shows that Australian wild rices possess 2.5 times more single nucleotide polymorphisms than in the Asian wild rice and cultivated O. sativa ssp. indica. Analysis of the genome of domesticated rice reveals regions of low diversity that show very little variation (polymorphism deserts. Both the perennial and annual wild rice from Australia show a high degree of conservation of sequence with that found in cultivated rice in the same 4.58 Mbp region on chromosome 5, which suggests that some of the 'polymorphism deserts' in this and other parts of the rice genome may have originated prior to domestication due to natural selection. CONCLUSIONS: Analysis of genes in the 'polymorphism deserts' indicates that this selection may have been due to biotic or abiotic stress in the environment of early rice relatives. Despite having closely related sequences in these genome regions, the Australian wild populations represent an invaluable source of diversity supporting rice food security.
Arsenate Removal: Comparison of FSM-16 with Low Cost Modified Rice Husk

International Nuclear Information System (INIS)

Daifullah, A.A.M.

2004-01-01

The recently discovered meso porous molecular sieve FSM-16 was tested as an absorbent for arsenic (V) sorption from aqueous solutions. Its adsorption behavior was evaluated and compared with a low cost sorbent prepared from available agroresidue, rice husk, (boiled with 5% KOH followed by 10 % HCl). Factors affecting sorption of arsenate ions by the two sorbents (e.g., porosity, surface area of the sorbent, equilibrium time, adsorption rate, ph and temperature) were studied using ICP-MS for analysis. The data of adsorption of the two systems were described according to the S-Langmuir type according to the initial slope. The monolayer coverage was 92 and 68 mg/g for FSM-16 and modified rice husk (MRH),respectively, due to the silica content of the former is higher than the latter. The thermodynamic parameters were evaluated and indicated that this adsorption is endothermic process.It was found that the adsorptive capacity for arsenate using MRH represents 75% of that FSM-16. Therefore, the MRH is useful in the removal of arsenate ions due to its low cost, availability, and its good efficiency in this application and no need to be regenerated
Ethanol production from rice on radioactively contaminated field toward sustainable rice farming

International Nuclear Information System (INIS)

Yokoyama, Shinya; Izumi, Bintaro; Oki, Kazuo

2011-01-01

Radioactive species such as 137 Cs were discharged from Fukushima Daiichi Nuclear Power Plant which was severely damaged by the enormous earthquake and tsunami. Cropland has been radioactively contaminated by 137 Cs etc. and it seems impossible to plant rice due to the non-suitability for food. According to the reports, 137 Cs transferred into the rice from soil is less than 1% on the average. Therefore, it is expected that the concentration of 137 Cs in bioethanol will be well below the tentative restriction value even if bioethanol could be produced from the rice. It is proposed that the rice field should be filled with water to avoid the flow of runoff contaminated by radioactive cesium compounds because they are insoluble in aqueous phase and that bioethanol should be produced from the rice in order to maintain the multifunction of rice field and to continue the agriculture. If rice farming is halted and neglected, agricultural function of rice field as well as local community will be permanently destroyed. (author)
Prevalence of Rice Yellow Mottle Virus (RYMV) on Rice Plants ...

African Journals Online (AJOL)

Abstract. Incidence of Rice yellow mottle virus (RYMV) on rice plants (ofada) grown in two local government areas (LGAs) of Ogun State had been evaluated during a two year field survey. Six month old rice plants were observed for symptom expression and leaf samples collected for serological indexing. Of the 60 leaf ...
Effect of Interplanting with Zero Tillage and Straw Manure on Rice Growth and Rice Quality

Directory of Open Access Journals (Sweden)

Shi-ping LIU

2007-09-01

Full Text Available The interplanting with zero-tillage of rice, i.e. direct sowing rice 10–20 days before wheat harvesting, and remaining about 30-cm high stubble after cutting wheat or rice with no tillage, is a new cultivation technology in wheat-rice rotation system. To study the effects of interplanting with zero tillage and straw manure on rice growth and quality, an experiment was conducted in a wheat-rotation rotation system. Four treatments, i.e. ZIS (Zero-tillage, straw manure and rice interplanting, ZI (Zero-tillage, no straw manure and rice interplanting, PTS (Plowing tillage, straw manure and rice transplanting, and PT (Plowing tillage, no straw manure and rice transplanting, were used. ZIS reduced plant height, leaf area per plant and the biomass of rice plants, but the biomass accumulation of rice at the late stage was quicker than that under conventional transplanting cultivation. In the first year (2002, there was no significant difference in rice yield among the four treatments. However, rice yield decreased in interplanting with zero-tillage in the second year (2003. Compared with the transplanting treatments, the number of filled grains per panicle decreased but 1000-grain weight increased in interplanting with zero-tillage, which were the main factors resulting in higher yield. Interplanting with zero-tillage improved the milling and appearance qualities of rice. The rates of milled and head rice increased while chalky rice rate and chalkiness decreased in interplanting with zero-tillage. Zero-tillage and interplanting also affected rice nutritional and cooking qualities. In 2002, ZIS showed raised protein content, decreased amylose content, softer gel consistency, resulting in improved rice quality. In 2003, zero-tillage and interplanting decreased protein content and showed similar amylose content as compared with transplanting treatments. Moreover, protein content in PTS was obviously increased in comparison with the other three treatments
An overview of the sustainability of rice agroecosystem through rice-fish integration

International Nuclear Information System (INIS)

Ahyaudin Ali

2002-01-01

Rice-fish integration in the rice agroecosystem has been introduced and is expanding in Malaysia. This type of farm integration has resulted in land optimization, thus enabling farmers to grow both fish and rice in one farming system. Introducing fish into the ricefield has also increased seasonal income as well as reduced pesticide use. Although basic ecological knowledge on rice-fish integration has allowed rice-fish integration to be introduced, further research is required to allow for fine tuning of the methodologies used. Thus research on the ecology, management, production methods and the characterization of rice-fish farming system of Malaysia is needed. Further characterization and description is needed on the ecology of the rice-fish farming system of Malaysia in terms of production, food webs, nutrient flow and system diversity. To increase the sustainability efficiency and productivity of the system, implementation of management techniques formulated through research is required. (Author)
Gas Separation through Bilayer Silica, the Thinnest Possible Silica Membrane.

Science.gov (United States)

Yao, Bowen; Mandrà, Salvatore; Curry, John O; Shaikhutdinov, Shamil; Freund, Hans-Joachim; Schrier, Joshua

2017-12-13

Membrane-based gas separation processes can address key challenges in energy and environment, but for many applications the permeance and selectivity of bulk membranes is insufficient for economical use. Theory and experiment indicate that permeance and selectivity can be increased by using two-dimensional materials with subnanometer pores as membranes. Motivated by experiments showing selective permeation of H 2 /CO mixtures through amorphous silica bilayers, here we perform a theoretical study of gas separation through silica bilayers. Using density functional theory calculations, we obtain geometries of crystalline free-standing silica bilayers (comprised of six-membered rings), as well as the seven-, eight-, and nine-membered rings that are observed in glassy silica bilayers, which arise due to Stone-Wales defects and vacancies. We then compute the potential energy barriers for gas passage through these various pore types for He, Ne, Ar, Kr, H 2 , N 2 , CO, and CO 2 gases, and use the data to assess their capability for selective gas separation. Our calculations indicate that crystalline bilayer silica, which is less than a nanometer thick, can be a high-selectivity and high-permeance membrane material for 3 He/ 4 He, He/natural gas, and H 2 /CO separations.
Use of nitrogen from fertilizer and cover crops by upland rice in an Oxisol under no-tillage in the Cerrado

Energy Technology Data Exchange (ETDEWEB)

Silva, Edson Cabral da; Muraoka, Takashi; Bendassolli, Jose Alberto, E-mail: edsoncabralsilva@gmail.com, E-mail: muraoka@cena.usp.br, E-mail: jab@cena.usp.br [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil); Franzini, Vinicius Ide, E-mail: vinicius.franzini@embrapa.br [Embrapa Amazonia Oriental, Belem, PA (Brazil); Sakadevan, Karuppan, E-mail: K.Sakadevan@iaea.org [Joint FAO/IAEA, Division of Nuclear Techniques in Food and Agriculture, Soil and Water Management and Crop Nutrition Subprogram, Vienna International Centre, Vienna (Austria); Buzetti, Salatier; Arf, Orivaldo, E-mail: sbuzetti@agr.feis.unesp.br, E-mail: arf@agr.feis.unesp.br [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Ilha Solteira, SP (Brazil). Faculdade de Engenharia; Soares, Frederico Antonio Loureiro, E-mail: fredalsoares@hotmail.com [Instituto Federal Goiano, Rio Verde, GO (Brazil)

2016-06-15

The objective of this work was to evaluate the effects of cover crops on the yield of upland rice (Oryza sativa) grown under no-tillage system, in the presence and absence of N fertilizer, as well as to quantify, in the field, the use efficiency of N from urea and cover crops by upland rice, through the {sup 15}N isotope dilution technique. The field experiment was carried out in the municipality of Selviria, in the state of Mato Grosso do Sul, Brazil, in an Oxisol (Rhodic Hapludox) in the Cerrado (Brazilian savanna) region. The experimental design was a randomized complete block with 15 treatments and four replicates, in a 5 x 3 factorial arrangement. The treatments were four cover crops (Crotalaria juncea, Cajanus cajan, Mucuna pruriens, and Pennisetum glaucum) + spontaneous vegetation (fallow in off-season), combined with three forms of N fertilization: control treatment, without N fertilizer application; 20 kg ha{sup -1} N at sowing; and 20 kg ha{sup -1} N at sowing plus 60 kg ha{sup -1} N as topdressing. Rice is not affected by N fertilizer application as topdressing, when legume cover crops are used. The use of legume cover crops provides higher grain yield and use of fertilizer-N by rice than that of millet or fallow. Legume cover crops promote an effect equivalent to that of the application of 60 kg ha{sup -1} N as urea on rice yield. (author)
Use of nitrogen from fertilizer and cover crops by upland rice in an Oxisol under no-tillage in the Cerrado

International Nuclear Information System (INIS)

Silva, Edson Cabral da; Muraoka, Takashi; Bendassolli, Jose Alberto; Franzini, Vinicius Ide; Sakadevan, Karuppan; Buzetti, Salatier; Arf, Orivaldo

2016-01-01

The objective of this work was to evaluate the effects of cover crops on the yield of upland rice (Oryza sativa) grown under no-tillage system, in the presence and absence of N fertilizer, as well as to quantify, in the field, the use efficiency of N from urea and cover crops by upland rice, through the 15 N isotope dilution technique. The field experiment was carried out in the municipality of Selviria, in the state of Mato Grosso do Sul, Brazil, in an Oxisol (Rhodic Hapludox) in the Cerrado (Brazilian savanna) region. The experimental design was a randomized complete block with 15 treatments and four replicates, in a 5 x 3 factorial arrangement. The treatments were four cover crops (Crotalaria juncea, Cajanus cajan, Mucuna pruriens, and Pennisetum glaucum) + spontaneous vegetation (fallow in off-season), combined with three forms of N fertilization: control treatment, without N fertilizer application; 20 kg ha -1 N at sowing; and 20 kg ha -1 N at sowing plus 60 kg ha -1 N as topdressing. Rice is not affected by N fertilizer application as topdressing, when legume cover crops are used. The use of legume cover crops provides higher grain yield and use of fertilizer-N by rice than that of millet or fallow. Legume cover crops promote an effect equivalent to that of the application of 60 kg ha -1 N as urea on rice yield. (author)
Objective evaluation of whiteness of cooked rice and rice cakes using a portable spectrophotometer.

Science.gov (United States)

Goto, Hajime; Asanome, Noriyuki; Suzuki, Keitaro; Sano, Tomoyoshi; Saito, Hiroshi; Abe, Yohei; Chuba, Masaru; Nishio, Takeshi

2014-03-01

The whiteness of cooked rice and rice cakes was evaluated using a portable spectrophotometer with a whiteness index (WI). Also, by using boiled rice for measurement of Mido values by Mido Meter, it was possible to infer the whiteness of cooked rice without rice cooking. In the analysis of varietal differences of cooked rice, 'Tsuyahime', 'Koshihikari' and 'Koshinokaori' showed high whiteness, while 'Satonoyuki' had inferior whiteness. The whiteness of rice cakes made from 'Koyukimochi' and 'Dewanomochi' was higher than the whiteness of those made from 'Himenomochi' and 'Koganemochi'. While there was a significant correlation (r = 0.84) between WI values and whiteness scores of cooked rice by the sensory test, no correlation was detected between the whiteness scores and Mido values, indicating that the values obtained by a spectrophotometer differ from those obtained by a Mido Meter. Thus, a spectrophotometer may be a novel device for measurement of rice eating quality.

Puffing of okara/rice blends using a rice cake machine.

Science.gov (United States)

Xie, M; Huff, H; Hsieh, F; Mustapha, A

2008-10-01

Okara is the insoluble byproduct of soymilk and tofu manufactures. It is cheap, high in nutrients, and possesses great potential to be applied to functional human foods. In this study, a puffed okara/rice cake product was developed with blends of okara pellets and parboiled rice. Consumer preference and acceptance tests were conducted for the product. Okara pellets were prepared by grinding the strands obtained from extruding a mixture of dried okara and rice flour (3:2, w/w) with a twin-screw extruder. Okara pellets and parboiled rice were blended in 4 ratios, 90:10, 70:30, 40:60, and 0:100 (w/w), and tempered to 14% and 17% moisture. The blends were puffed at 221, 232, and 243 degrees C for 4, 5, or 6 s. The okara/rice cakes were evaluated for specific volume (SPV), texture, color, and percent weight loss after tumbling. Overall, the decrease in okara content and increase in moisture, heating temperature and time led to greater specific volume (SPV) and hardness, lighter color, and lower percent weight loss after tumbling. The consumer tests indicated that the okara/rice cake containing 70% okara pellets was preferred and the 90% one was liked the least. The possible drivers of liking for the puffed okara/rice cakes could be the okara content, hardness, SPV, bright color, and percent weight loss after tumbling.
Diversity of some endophytic fungi associated with rice black bug Paraeucosmetus pallicornis on rice plant

OpenAIRE

Nur, Amin; La Daha; Nurariaty, Agus; Ade, Rosmana; Muh., Fadlan

2015-01-01

A new rice insect pest was sighted in some rice producing areas of South Sulawesi Province, Indonesia. This pest is rice black bugs Paraeucosmetus pallicornis. The research aimed to isolation of fungi associated with rice black bugs Paraeucosmetus pallicornis, so as to know the cause of a bitter taste to the rice. The isolation of the fungi consist of three kinds of treatment, namely rice black bugs without sterilization, with sterilization and rice black bugs cut and sterilized. The resul...
RiceAtlas, a spatial database of global rice calendars and production

NARCIS (Netherlands)

Laborte, Alice G.; Gutierrez, Mary Anne; Balanza, Jane Girly; Saito, Kazuki; Zwart, Sander; Boschetti, Mirco; Murty, M. V.R.; Villano, Lorena; Aunario, Jorrel Khalil; Reinke, Russell; Koo, Jawoo; Hijmans, Robert J.; Nelson, Andrew

2017-01-01

Knowing where, when, and how much rice is planted and harvested is crucial information for understanding the effects of policy, trade, and global and technological change on food security. We developed RiceAtlas, a spatial database on the seasonal distribution of the world's rice production. It
The Potency of White Rice (Oryza sativa), Black Rice (Oryza sativa L. indica), and Red Rice (Oryza nivara) as Antioxidant and Tyrosinase Inhibitor

Science.gov (United States)

Batubara, I.; Maharni, M.; Sadiah, S.

2017-04-01

Rice is known to have many beneficial biological activities and is often used as “bedak dingin”, a face powder. The content of vitamins, minerals, fiber, and several types of antioxidants, such as ferulic acid, phytic acid, tocopherol, and oryzanols [1-2] are predicted to be potential as a tyrosinase inhibitor. The purpose of this study is to determine the potency of extracts from there types of rice, namely white, red, and black rice as an antioxidant and tyrosinase inhibitor. The rice was extracted with three different solvents, n-hexane, ethyl acetate, and methanol. The results showed that the highest antioxidant activity using 1,1-diphenyl-2-picrylhydrazyl method was found in the methanol extract of black rice (IC50 290 μg/mL). Meanwhile, ethyl acetate extract of white rice has the highest antioxidant activity withphosphomolybdic acid method (41 mmol α-tocopherol equivalents/g sample). Thus, methanol extract of black rice and ethyl acetate extract of white rice are potential as an antioxidant. For tyrosinase inhibitor, n-hexane extract of red rice (IC50 3156 μg/mL) was the most active extract. The active component for radical scavenging is polar compound and for antioxidant by phosphomolybdate method is less polar compounds in black rice methanol extract based on TLC bioautogram. In conclusion, the black rice is the most potent in antioxidant while red rice is for tyrosinase inhibition.
Effect of Rice bran on the Quality of Rice Flour Breads (Gluten-free)

OpenAIRE

仲上, 晴世; 矢部, えん; Haruyo, Nakagami; En, Yabe

2016-01-01

Over recent years progress has been made in the development of substitute foods for allergy patients. One such is rice flour bread. However, typically rice flour bread uses polysaccharide thickener in substitution for the gluten in wheat. Most polysaccharide thickeners are of dietary fiber origin, and the nutritive value is poor. Therefore, in this study, I made rice flour bread adding rice bran in place of polysaccharide thickener. Various nutrients are included in rice bran, including vitam...
Synthesis of uniform carbon at silica nanocables and luminescent silica nanotubes with well controlled inner diameters

International Nuclear Information System (INIS)

Qian Haisheng; Yu Shuhong; Ren Lei; Yang Yipeng; Zhang Wei

2006-01-01

Uniform carbon at silica nanocables and silica nanotubes with well-controlled inner diameters can be synthesized in an easy way by a sacrificial templating method. This was performed using carbon nanofibres as hard templates that were synthesized previously by a hydrothermal carbonization process. Silica nanotubes with well-controlled inner diameters were synthesized from carbon at silica core-shell nanostructures by removal of the core carbon component. The inner diameters of the as-prepared silica nanotubes can be well controlled from several nanometres to hundreds of nanometres by adjusting the diameters of the carbon nanofibres. The silica nanotubes synthesized by this method display strong photoluminescence in ultraviolet at room temperature. Such uniform silica nanotubes might find potential applications in many fields such as encapsulation, catalysis, chemical/biological separation, and sensing
Silica/Perfluoropolymer nanocomposites fabricated by direct melt-compounding: a novel method without surface modification on nano-silica.

Science.gov (United States)

Tanahashi, Mitsuru; Hirose, Masaki; Watanabe, Yusuke; Lee, Jeong-Chang; Takeda, Kunihiko

2007-07-01

A novel method for the fabrication of silica/perfluoropolymer nanocomposites was investigated, whereby nano-sized silica particles without surface modification were dispersed uniformly through mechanical breakdown of loosely packed agglomerates of silica nanoparticles with low fracture strength in a polymer melt during direct melt-compounding. The method consists of two stages. The first stage involves preparation of the loose silica agglomerate, and the second stage involves melt-compounding of a completely hydrophobic perfluoropolymer, poly(tetrafluoroethyleneco-perfluoropropylvinylether), with the loose silica agglomerates prepared in the first stage. In the first stage, the packing structure and the fracture strength of the silica agglomerate were controlled by destabilizing an aqueous colloidal silica solution with a mean primary diameter of 190 nm via pH control and salt addition. In the next stage, the silica/perfluoropolymer nanocomposite was fabricated by breaking down the prepared loose silica agglomerates with low fracture strength by means of a shear force inside the polymer melt during melt-compounding.
Rice peasants and rice research in Colombia

NARCIS (Netherlands)

Spijkers, P.A.N.M.

1983-01-01

Rice has been grown as a food crop in Latin America from early colonial times. In Colombia rice became a prominent subsistence crop especially on the north coast where it has been grown since the 17th century, sometimes also as a commercial crop. During the last twenty years there has been a sharp
Leaf development of cultivated rice and weedy red rice under elevated temperature scenarios

OpenAIRE

Streck,Nereu A.; Uhlmann,Lilian O.; Gabriel,Luana F.

2013-01-01

The objective of this study was to simulate leaf development of cultivated rice genotypes and weedy red rice biotypes in climate change scenarios at Santa Maria, RS, Brazil. A leaf appearance (LAR) model adapted for rice was used to simulate the accumulated leaf number, represented by the Haun Stage, from crop emergence to flag leaf appearance (EM-FL). Three cultivated rice genotypes and two weedy red rice biotypes in six emergence dates were used. The LAR model was run for each emergence dat...
Sonochemical coating of magnetite nanoparticles with silica.

Science.gov (United States)

Dang, Feng; Enomoto, Naoya; Hojo, Junichi; Enpuku, Keiji

2010-01-01

Magnetite nanoparticles were coated with silica through the hydrolysis and condensation of tetraethyl orthosilicate (TEOS) under ultrasonic irradiation. The ultrasonic irradiation was used to prevent the agglomeration of the magnetite particles and accelerate the hydrolysis and condensation of TEOS. TEM, DLS, XRF, VSM, TG and sedimentation test were used to characterize the silica-coated magnetite particles. The dispersibility of silica-coated magnetite particles in aqueous solution was improved significantly and the agglomerate particle size was decreased to 110 nm. It was found that the agglomerate particle size of silica-coated magnetite particles was mainly decided by the coating temperature and the pH value in the silica-coating process. The weight ratio of silica in silica-coated magnetite particles was mainly decided by the pH value in the silica-coating process. The dispersibility of silica-coated magnetite particles was mainly decided by the agglomerate particle size of the suspension. The oxidation of magnetite particles in air was limited through the coated silica. The magnetism of silica-coated magnetite particles decreased slightly after silica-coating.
Nutritional test of rice in rats

International Nuclear Information System (INIS)

Horii, Masaji; Yoshikawa, Seiji

1980-01-01

Behaviors on N derived from rice were followed up by means of 15 N-labeled rice. In the first test, the single unpolished rice diet and the diet of rice and bean lecithin (4.5%) produced urinary excretion of 10 - 12% of 15 N, and that of rice and mannan from devil's tongue (3%), 16 - 20%. The single unpolished rice diet showed slightly more urinary excretion of 15 N, and the other 2 diets showed a similar proportion of 15 N in 3 days. The results indicated that the diet containing mannan from devil's tongue resulted in a poor N absorption by rice, a large quantity of N being excreted over a long period of time. This suggested differences and time lags in the excretion of rice N into the stool and urine depending on the diet constitution. With the unpolished rice diet, a small quantity of rice protein was not absorbed, but was excreted. In the 2nd test with 15 N-polished rice, the urinary excretion rate was 11.44% for a single rice diet, 11.16% for a mixed diet of rice and bean (1:1 in protein), 10.99% for rice and egg yolk, 9.66% for rice, bean and egg yolk and 8.10% for rice and bean lecithin. This decrease in urinary excretion indicated a corresponding increase in absorption of rice protein. (Chiba, N.)
Silica reinforced triblock copolymer gels

DEFF Research Database (Denmark)

Theunissen, E.; Overbergh, N.; Reynaers, H.

2004-01-01

The effect of silica and polymer coated silica particles as reinforcing agents on the structural and mechanical properties of polystyrene-poly(ethylene/butylene)-polystyrene (PS-PEB-PS) triblock gel has been investigated. Different types of chemically modified silica have been compared in order...
Effect of silica concentration on electrical conductivity of epoxy resin-carbon black-silica nanocomposites

International Nuclear Information System (INIS)

Zhang Wei; Blackburn, Richard S.; Dehghani-Sanij, Abbas A.

2007-01-01

Electrical properties of nanocomposites are determined by the conductive paths of carbon black and influenced by a 'network' of silica. With increasing content of silica, carbon black (CB) particles are optimally dispersed, contributing to the generation of a conductive network between CB particles via direct particle contact and a tunneling effect; maximum conductivity for the epoxy resin-CB-silica nanocomposite described herein occurs at a ratio of 0.6:1.0 (SiO 2 :CB). As a non-conductive component, excessive silica will prevent electron flow, giving rise to low conductivity
Rice Husk Ash to Stabilize Heavy Metals Contained in Municipal Solid Waste Incineration Fly Ash: First Results by Applying New Pre-treatment Technology

Directory of Open Access Journals (Sweden)

Laura Benassi

2015-10-01

Full Text Available A new technology was recently developed for municipal solid waste incineration (MSWI fly ash stabilization, based on the employment of all waste and byproduct materials. In particular, the proposed method is based on the use of amorphous silica contained in rice husk ash (RHA, an agricultural byproduct material (COSMOS-RICE project. The obtained final inert can be applied in several applications to produce “green composites”. In this work, for the first time, a process for pre-treatment of rice husk, before its use in the stabilization of heavy metals, based on the employment of Instant Pressure Drop technology (DIC was tested. The aim of this work is to verify the influence of the pre-treatment on the efficiency on heavy metals stabilization in the COSMOS-RICE technology. DIC technique is based on a thermomechanical effect induced by an abrupt transition from high steam pressure to a vacuum, to produce changes in the material. Two different DIC pre-treatments were selected and thermal annealing at different temperatures were performed on rice husk. The resulting RHAs were employed to obtain COSMOS-RICE samples, and the stabilization procedure was tested on the MSWI fly ash. In the frame of this work, some thermal treatments were also realized in O2-limiting conditions, to test the effect of charcoal obtained from RHA on the stabilization procedure. The results of this work show that the application of DIC technology into existing treatment cycles of some waste materials should be investigated in more details to offer the possibility to stabilize and reuse waste.
Rice Husk Ash to Stabilize Heavy Metals Contained in Municipal Solid Waste Incineration Fly Ash: First Results by Applying New Pre-treatment Technology

Science.gov (United States)

Benassi, Laura; Franchi, Federica; Catina, Daniele; Cioffi, Flavio; Rodella, Nicola; Borgese, Laura; Pasquali, Michela; Depero, Laura E.; Bontempi, Elza

2015-01-01

A new technology was recently developed for municipal solid waste incineration (MSWI) fly ash stabilization, based on the employment of all waste and byproduct materials. In particular, the proposed method is based on the use of amorphous silica contained in rice husk ash (RHA), an agricultural byproduct material (COSMOS-RICE project). The obtained final inert can be applied in several applications to produce “green composites”. In this work, for the first time, a process for pre-treatment of rice husk, before its use in the stabilization of heavy metals, based on the employment of Instant Pressure Drop technology (DIC) was tested. The aim of this work is to verify the influence of the pre-treatment on the efficiency on heavy metals stabilization in the COSMOS-RICE technology. DIC technique is based on a thermomechanical effect induced by an abrupt transition from high steam pressure to a vacuum, to produce changes in the material. Two different DIC pre-treatments were selected and thermal annealing at different temperatures were performed on rice husk. The resulting RHAs were employed to obtain COSMOS-RICE samples, and the stabilization procedure was tested on the MSWI fly ash. In the frame of this work, some thermal treatments were also realized in O2-limiting conditions, to test the effect of charcoal obtained from RHA on the stabilization procedure. The results of this work show that the application of DIC technology into existing treatment cycles of some waste materials should be investigated in more details to offer the possibility to stabilize and reuse waste. PMID:28793605
Side-effects of pesticides used in irrigated rice areas on Telenomus podisi Ashmead (Hymenoptera: Platygastridae).

Science.gov (United States)

Pazini, Juliano de Bastos; Pasini, Rafael Antonio; Seidel, Enio Júnior; Rakes, Matheus; Martins, José Francisco da Silva; Grützmacher, Anderson Dionei

2017-08-01

Telenomus podisi Ashmead (Hymenoptera: Platygastridae) is an important agent for the biological control of stink bug eggs in irrigated rice areas and the best strategy for its preservation is the use of selective pesticides. The aim of this study was to know the side-effects of pesticides used in Brazilian irrigated rice areas on egg parasitoid T. podisi. We evaluated, under laboratory conditions, 13 insecticides, 11 fungicides, 11 herbicides, and a control (distilled water) in choice and no-choice tests. In the no-choice tests, the pesticides were sprayed at pre and post-parasitism stages (egg and larval stages of T. podisi). In the choice tests, sprays were conducted only at pre-parasitism stages. For all tests, we prepared cards with 25 eggs of the alternative host Euschistus heros (Fabricius) (Hemiptera: Pentatomidae) non-parasitized (pre-parasitism) and parasitized (post-parasitism), which were subjected to pesticide sprays. The parasitism and emergence rates of T. podisi were determined classifying the pesticides in terms of the reduction of parasitism or emergence rates compared to the control. The neurotoxic insecticide cypermethrin, lambda-cyhalothrin, zeta-cypermethrin, etofenprox, thiamethoxam, thiamethoxam + lambda-cyhalothrin, acetamiprid + alpha-cypermethrin, and bifenthrin + alpha-cypermethrin + carbosulfan were more harmful to T. podisi and, therefore, are less suitable for the integrated management of insect pests in irrigated rice areas.
Glufosinate herbicide-tolerant (LibertyLink) rice vs. conventional rice in diets for growing-finishing swine.

Science.gov (United States)

Cromwell, G L; Henry, B J; Scott, A L; Gerngross, M F; Dusek, D L; Fletcher, D W

2005-05-01

Genetically modified (GM) rice (LibertyLink, event LLRICE62) that is tolerant to glufosinate ammonium (Liberty) herbicide was compared with a near-isogenic (NI) conventional medium-grain brown rice (cultivar, Bengal) and a commercially milled long-grain brown rice in diets for growing-finishing pigs. The GM and NI rice were grown in 2000. The GM rice was from fields treated (GM+) or not treated (GM-) with glufosinate herbicide. The GM- and NI rice were grown using herbicide regimens typical of southern United States rice production practices. The four rice grains were similar in composition. Growing-finishing pigs (n = 96) were fed fortified rice-soybean meal diets containing the four different rice grains from 25 to 106 kg BW. Diets contained 0.99% lysine initially (growing phase), with lysine decreased to 0.80% (early finishing phase) and 0.65% (late finishing phase), when pigs reached 51 and 77 kg, respectively. The percentage of rice in the four diets was constant during each of the three phases (72.8, 80.0, and 85.8% for the growing, early-finishing, and late-finishing phases, respectively). There were six pen replicates (three pens of barrows and three pens of gilts) and four pigs per pen for each dietary treatment. All pigs were slaughtered at the termination of the study to collect carcass data. At the end of the 98-d experiment, BW gain, feed intake (as-fed basis), and feed:gain ratio did not differ (P > 0.05) for pigs fed the GM+ vs. conventional rice diets, but growth performance traits of pigs fed the GM+ rice diets were superior (P glufosinate herbicide-tolerant rice was similar in composition and nutritional value to conventional rice for growing-finishing pigs.
Asian wild rice is a hybrid swarm with extensive gene flow and feralization from domesticated rice.

Science.gov (United States)

Wang, Hongru; Vieira, Filipe G; Crawford, Jacob E; Chu, Chengcai; Nielsen, Rasmus

2017-06-01

The domestication history of rice remains controversial, with multiple studies reaching different conclusions regarding its origin(s). These studies have generally assumed that populations of living wild rice, O. rufipogon , are descendants of the ancestral population that gave rise to domesticated rice, but relatively little attention has been paid to the origins and history of wild rice itself. Here, we investigate the genetic ancestry of wild rice by analyzing a diverse panel of rice genomes consisting of 203 domesticated and 435 wild rice accessions. We show that most modern wild rice is heavily admixed with domesticated rice through both pollen- and seed-mediated gene flow. In fact, much presumed wild rice may simply represent different stages of feralized domesticated rice. In line with this hypothesis, many presumed wild rice varieties show remnants of the effects of selective sweeps in previously identified domestication genes, as well as evidence of recent selection in flowering genes possibly associated with the feralization process. Furthermore, there is a distinct geographical pattern of gene flow from aus , indica , and japonica varieties into colocated wild rice. We also show that admixture from aus and indica is more recent than gene flow from japonica , possibly consistent with an earlier spread of japonica varieties. We argue that wild rice populations should be considered a hybrid swarm, connected to domesticated rice by continuous and extensive gene flow. © 2017 Wang et al.; Published by Cold Spring Harbor Laboratory Press.
An Economic Risk Analysis of Weed Suppressive Rice Cultivars in Rice Production

Science.gov (United States)

Weeds are a major constraint to rice production. In the United States, most rice cultivars are not inherently weed-suppressive and require substantial herbicide inputs to achieve agronomic and economic viability. Intensive herbicide application in rice also has many potential drawbacks, resulting in...
Soil to rice transfer factors for 210Pb: a study on rice grown in India

International Nuclear Information System (INIS)

Karunakara, N.; Rao, Chetan; Ujwal, P.; Yashodhara, I.; Sudeep Kumara; Somashekarappa, H.M.; Bhaskara Shenoy, K.; Ravi, P.M.

2013-01-01

India is the second largest producer of rice (Oryza sativa L.) in the world and rice is the essential component of the diet for the majority of the population of India. However, detailed studies aimed at evaluation of radionuclide transfer factors (F v ) for rice grown in India are almost non-existent. This paper presents soil to rice transfer factors for 210 Pb for rice grown in natural field conditions on the West Coast of India. A rice field was developed very close to the Kaiga nuclear power plant for the field studies. For a comparative study of radionuclide transfer factors, rice samples were also collected from the rice fields of nearby villages. The soil to un-hulled rice grain 210 Pb varied in the range <1.2 x10 -2 to 8.1 x 10 -1 with a mean of 1.4 x 10 -1 . The mean values of un-hulled grain to white rice processing retention factors (F r ) was 0.03 for 210 Pb. Using the processing retention factors the soil to white rice transfer factor was estimated and found to have the mean value of 4.2 x 10 -3 . The study has shown that the transfer of 210 Pb was retained in the root and its transfer to above ground organs of rice plant is significantly lower. (author)

A comparative study of competitiveness between different genotypes of weedy rice (Oryza sativa) and cultivated rice.

Science.gov (United States)

Dai, Lei; Dai, Weimin; Song, Xiaoling; Lu, Baorong; Qiang, Sheng

2014-01-01

Competition from weedy rice can cause serious yield losses to cultivated rice. However, key traits that facilitate competitiveness are still not well understood. To explore the mechanisms behind the strong growth and competitive ability, replacement series experiments were established with six genotypes of weedy rice from different regions and one cultivated rice cultivar. (1) Weedy rice from southern China had the greatest impact on growth and yield of cultivated rice throughout the entire growing season. Weedy rice from the northeast was very competitive during the early vegetative stage while the competitive effects of eastern weedy rice were more detrimental at later crop-growth stages. (2) As the proportion of weedy rice increased, plant height, tillers, above-ground biomass, and yield of cultivated rice significantly declined; the crop always being at disadvantage regardless of proportion. (3) Weedy biotypes with greater diversity as estimated by their Shannon indexes were more detrimental to the growth and yield of cultivated rice. Geographic origin (latitude) of weedy rice biotype, its mixture proportion under competition with the crop and its genetic diversity are determinant factors of the outcome of competition and the associated decline in the rice crop yield. © 2013 Society of Chemical Industry. © 2013 Society of Chemical Industry.
Diversity of global rice markets and the science required for consumer-targeted rice breeding

Science.gov (United States)

With the ever-increasing global demand for high quality rice in both local production regions and with Western consumers, we have a strong desire to understand better the importance of different quality traits that make up the rice grain and obtain a full picture of rice quality demographics. Rice ...
Laboratory Screening for Resistance in Rice to Rice Stem Borer Chilo Suppressalis Walker

International Nuclear Information System (INIS)

Singgih Sutrisno

2004-01-01

Rice stem borer Chilo suppressalis Walker is one of the major insect pests in rice in Indonesia. The use of insect pest resistant variety of rice is one of the effective techniques against pests. Breeding of resistance to insect pests rice crops often faced difficulties in obtaining a lot of insect amounts due to the unavailability of enough number insects pests in the field so that a laboratory bioassay is needed. In this experiments five rice varieties were used: a Pelita I/1, Atomita I, Cisadane, Cisanggarung, and IR 36. Rice seedling 7 days of age were put in 1 liter plastic vials for rice resistance test against the attack of insect pest C. suppressalis. The parameters observed were larval and pupal viability, pupal weight, and eggs production. The larval and pupal viability which were reared on of Pelita I/1 and Atomita I rice seedlings were 68.5 % - 55.5 % and 57.3 % - 46.7 % respectively. The respective lowest percentages were found in IR 36 which was about 41.3 % - 29.8 % .The experiment results on the parameters of pupal weight and egg production showed similar results to that on the parameters of larval and pupal viability. Rice variety of IR 36 showed more resistance to the other varieties, while Pelita I/1 and Atomita I showed the most susceptible to the attack of insect pest C. suppressalis. (author)
Silica particles and method of preparation thereof

NARCIS (Netherlands)

2015-01-01

The invention is in the field of silica products. More in particular, the invention is in the field of amorphous silica particles. The invention is directed to amorphous silica particles and related products including clusters of said silica particles, a suspension of said silica particles, and an
Creation of transgenic rice plants producing small interfering RNA of Rice tungro spherical virus.

Science.gov (United States)

Le, Dung Tien; Chu, Ha Duc; Sasaya, Takahide

2015-01-01

Rice tungro spherical virus (RTSV), also known as Rice waika virus, does not cause visible symptoms in infected rice plants. However, the virus plays a critical role in spreading Rice tungro bacilliform virus (RTBV), which is the major cause of severe symptoms of rice tungro disease. Recent studies showed that RNA interference (RNAi) can be used to develop virus-resistance transgenic rice plants. In this report, we presented simple procedures and protocols needed for the creation of transgenic rice plants capable of producing small interfering RNA specific against RTSV sequences. Notably, our study showed that 60 out of 64 individual hygromycin-resistant lines (putative transgenic lines) obtained through transformation carried transgenes designed for producing hairpin double-stranded RNA. Northern blot analyses revealed the presence of small interfering RNA of 21- to 24-mer in 46 out of 56 confirmed transgenic lines. Taken together, our study indicated that transgenic rice plants carrying an inverted repeat of 500-bp fragments encoding various proteins of RTSV can produce small interfering RNA from the hairpin RNA transcribed from that transgene. In light of recent studies with other viruses, it is possible that some of these transgenic rice lines might be resistant to RTSV.
A Non-destructive and Continuous Measurement of Gelatinization of Rice in Rice Cooking Process

OpenAIRE

Hagura, Yoshio; Suzuki, Kanichi

2002-01-01

A non-destructive and continuous method to measure gelatinization of rice samples in a rice-water system during rice cooking process was examined. An aluminum pot and a lid of a rice cooker were used as two electrode plates, and changes in dielectric properties (capacitance : C, and dielectric dissipation factor : tan δ) of the samples in the rice cooking process were measured by a capacitance meter. Differential scanning calorimetry (DSC) was used to measure gelatinization enthalpy and to de...
7 CFR 868.310 - Grades and grade requirements for the classes Long Grain Milled Rice, Medium Grain Milled Rice...

Science.gov (United States)

2010-01-01

... Grain Milled Rice, Medium Grain Milled Rice, Short Grain Milled Rice, and Mixed Milled Rice. (See also Â... Milled Rice Principles Governing Application of Standards § 868.310 Grades and grade requirements for the classes Long Grain Milled Rice, Medium Grain Milled Rice, Short Grain Milled Rice, and Mixed Milled Rice...
Rice varieties in relation to rice bread quality.

Science.gov (United States)

Han, Hye Min; Cho, Jun Hyeon; Kang, Hang Won; Koh, Bong Kyung

2012-05-01

It is difficult to predict rice bread quality only from the amylose content (AC) or dough characteristics of new lines produced by rice breeding programmes. This study investigated the AC relative to bread baking quality of rice varieties developed in Korea, and identified specific characteristics that contribute to rice bread quality. Manmibyeo, Jinsumi, Seolgaeng and Hanareumbyeo were classified as low AC, YR24088 Acp9, Suweon517, Chenmaai and Goamibyeo as intermediate AC and Milyang261 as high AC. Suweon517, Milyang261 and Manmibyeo had a high water absorption index (WAI), while Goamibyeo, YR24088 Acp9, Jinsumi, Seolgaeng, Hanareumbyeo and Chenmaai had a low WAI. The gelatinisation enthalpy of flour varied from 9.2 J g(-1) in Milyang261 to 14.8 J g(-1) in YR24088 Acp9. After 7 days of storage the rate of flour retrogradation and crumb firmness were weakly correlated, with the exception of Jinsumi. Bread volumes of Jinsumi, Chenmaai, YR24088 Acp9 and Goamibyeo were comparable to that of wheat flour, but the rest were unsuited to bread making because of their low volume and hard crumb texture. Based on volume, texture and crumb firmness ratio, Chenmaai and Goamibyeo were the most appropriate varieties for making bread. An intermediate AC and low WAI were the primary indicators of rice bread flour quality. Copyright © 2011 Society of Chemical Industry.
A 400-year phytolith-based reconstruction of wild rice (Zizania palustris) abundance from Mud Lake core sediments, Fond du Lac Band of Lake Superior Chippewa Reservation, Minnesota, USA.

Science.gov (United States)

Munoz, R.; Caylor, E.; Yost, C. L.; Drake, C.; Ladwig, J. L.; Myrbo, A.; Howes, T.

2014-12-01

Wild rice (Zizania palustris L.) is an aquatic grass with spiritual and subsistence significance to Native people of the Great Lakes region of North America. Mud Lake (Mashkiigwaagamaag), located on the Fond du Lac Band of Lake Superior Chippewa Reservation in Carlton County, Minnesota, USA, once supported an extensive population of wild rice (manoomin). However, early 20th century attempts to ditch and drain surrounding wetlands for landuse intensification severely altered the natural hydrological system that supports wild rice. Fond du Lac Resource Management (FDLRM) technicians are currently working to increase the wild rice population in Mud Lake. As part of these efforts, this phytolith study was undertaken to better understand how wild rice abundance has fluctuated over the past 400 years, with particular emphasis on the 19th and 20th centuries. Phytoliths are microscopic opal silica plant remains that are incorporated into soils and lake sediments after the plant-parts that contain them decay. Wild rice produces phytolith morphotypes that are unequivocally diagnostic. Mud Lake core MNMN-MUD11-1C-1P-1 (46°43'38.39"N, 92°42'2.45"W) was piston cored by LacCore (National Lacustrine Core Facility) and FDLRM technicians on 24 May 2011. Initial core descriptions, multi-sensor core logging, phytolith sampling and phytolith extractions were completed during the summer of 2014 at LacCore. Wild rice phytolith identification and quantification was conducted on twelve samples using brightfield microscopy at 400x magnification. Wild rice phytolith concentration values ranged from 68 to 2,300 phytoliths/cm3. Wild rice accumulation rates ranged from 9 to 383 phytoliths/ cm2/yr, peaking in 1952 AD. Wild rice abundance in Mud Lake appears to be influenced by a complex set of variables that include anthropogenic disturbance, climatic events and aquatic plant community succession.
COOH-functionalisation of silica particles

Energy Technology Data Exchange (ETDEWEB)

Majewski, Peter, E-mail: peter.majewski@unisa.edu.au [School of Advanced Manufacturing and Mechanical Engineering, Mawson Institute, University of South Australia, Adelaide (Australia); Albrecht, Trent [Ian Wark Research Institute, University of South Australia, Adelaide (Australia); Weber, Siegfried [Department of Biotechnology, University of Applied Sciences, Mannheim (Germany)

2011-09-01

In this study COOH-functionalised silica is synthesised using phosphonateN-(phosphonomethyl)iminodiacetic acid (PMIDA) in an aqueous solution. The presence of PMIDA on the silica particles was verified using Fourier Transform Infrared Spectroscopy, X-ray Photoelectron Spectroscopy and titration. Experimentally, surface concentrations of COOH functional groups of up to about 3 mmol/g{sub silica} were achieved, whereas theoretical calculation of the maximum COOH functional group concentration gave about 1 mmol/g{sub silica}. The discrepancy may be caused by PMIDA multilayer formation on the particle.
Salinity alters the protein composition of rice endosperm and the physicochemical properties of rice flour.

Science.gov (United States)

Baxter, Graeme; Zhao, Jian; Blanchard, Christopher

2011-09-01

Salinity is one of the major threats to production of rice and other agricultural crops worldwide. Although numerous studies have shown that salinity can severely reduce rice yield, little is known about its impact on the chemical composition, processing and sensory characteristics of rice. The objective of the current study was to investigate the effect of salinity on the pasting and textural properties of rice flour as well as on the protein content and composition of rice endosperm. Rice grown under saline conditions had significantly lower yields but substantially higher protein content. The increase in protein content was mainly attributed to increases in the amount of glutelin, with lesser contributions from albumin. Salinity also altered the relative proportions of the individual peptides within the glutelin fraction. Flours obtained from rice grown under saline conditions showed significantly higher pasting temperatures, but lower peak and breakdown viscosities. Rice gels prepared from the flour showed significantly higher hardness and adhesiveness values, compared to the freshwater controls. Salinity can significantly affect the pasting and textural characteristics of rice flour. Although some of the effects could be attributed to changes in protein content of the rice flour, especially the increased glutelin level, the impact of salinity on the physicochemical properties of rice is rather complex and may involve the interrelated effects of other rice components such as starch and lipids. Copyright © 2011 Society of Chemical Industry.
Assessing the impacts of climate change on rice yields in the main rice areas of China

International Nuclear Information System (INIS)

Yao, Fengmei; Xu, Yinglong; Lin, Erda; Yokozawa, Masayuki; Zhang, Jiahua

2007-01-01

This paper assesses the impact of climate change on irrigated rice yield using B2 climate change scenario from the Regional Climate Model (RCM) and CERES-rice model during 2071--2090. Eight typical rice stations ranging in latitude, longitude, and elevation that are located in the main rice ecological zones of China are selected for impact assessment. First, Crop Estimation through Resource and Environment Synthesis (CERES)-rice model is validated using farm experiment data in selected stations. The simulated results represent satisfactorily the trend of flowering duration and yields. The deviation of simulation within ± 10% of observed flowering duration and ± 15% of observed yield. Second, the errors of the outputs of RCM due to the difference of topography between station point and grid point is corrected. The corrected output of the RCM used for simulating rice flowering duration and yield is more reliable than the not corrected. Without CO2 direct effect on crop, the results from the assessment explore that B2 climate change scenario would have a negative impact on rice yield at most rice stations and have little impacts at Fuzhou and Kunming. To find the change of inter-annual rice yield, a preliminary assessment is made based on comparative cumulative probability at low and high yield and the coefficient variable of yield between the B2 scenario and baseline. Without the CO2 direct effect on rice yield, the result indicates that frequency for low yield would increase and it reverses for high yield, and the variance for rice yield would increase. It is concluded that high frequency at low yield and high variances of rice yield could pose a threat to rice yield at most selected stations in the main rice areas of China. With the CO2 direct effect on rice yield, rice yield increase in all selected stations
Assessing the impacts of climate change on rice yields in the main rice areas of China

Energy Technology Data Exchange (ETDEWEB)

Yao, Fengmei [College of Earth Sciences, The Graduate University of the Chinese Academy of Sciences, 19A, Yuquan Road, Beijing, 100049 (China); Xu, Yinglong; Lin, Erda [Agricultural Environment and Sustainable Development Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081 (China); Yokozawa, Masayuki [National Institute for Agro-environmental Sciences, Tsukuba 305-8604 (Japan); Zhang, Jiahua [Chinese Academy of Meteorological Sciences, Beijing, 100081 (China)

2007-02-15

This paper assesses the impact of climate change on irrigated rice yield using B2 climate change scenario from the Regional Climate Model (RCM) and CERES-rice model during 2071--2090. Eight typical rice stations ranging in latitude, longitude, and elevation that are located in the main rice ecological zones of China are selected for impact assessment. First, Crop Estimation through Resource and Environment Synthesis (CERES)-rice model is validated using farm experiment data in selected stations. The simulated results represent satisfactorily the trend of flowering duration and yields. The deviation of simulation within {+-} 10% of observed flowering duration and {+-} 15% of observed yield. Second, the errors of the outputs of RCM due to the difference of topography between station point and grid point is corrected. The corrected output of the RCM used for simulating rice flowering duration and yield is more reliable than the not corrected. Without CO2 direct effect on crop, the results from the assessment explore that B2 climate change scenario would have a negative impact on rice yield at most rice stations and have little impacts at Fuzhou and Kunming. To find the change of inter-annual rice yield, a preliminary assessment is made based on comparative cumulative probability at low and high yield and the coefficient variable of yield between the B2 scenario and baseline. Without the CO2 direct effect on rice yield, the result indicates that frequency for low yield would increase and it reverses for high yield, and the variance for rice yield would increase. It is concluded that high frequency at low yield and high variances of rice yield could pose a threat to rice yield at most selected stations in the main rice areas of China. With the CO2 direct effect on rice yield, rice yield increase in all selected stations.
Radiation disinfestation of Basmati rice

International Nuclear Information System (INIS)

Rao, V.S.; Gholap, A.S.; Adhikari, H.R.; Nair, P.M.

1994-01-01

Effect of low dose γ-radiation on prepackaged Basmati rice was studied in order to achieve disinfestation of rice. Basmati rice procured from local market was repacked in 1 kg pouches made from high density polyethylene (HDP) and biaxially oriented polypropylene: low density polyethylene (BOPP/LDP) laminate and irradiated at doses from 0.25-1.0 kGy. Within one month of storage at room temperature, unirradiated (control) Basmati rice developed heavy infestation. No infestation was observed in any of the irradiated samples even at 0.25 kGy and the rice could be stored for 6 months in a clean state. Irradiation (at 0.25 kGy) did not alter the moisture content of the rice. Likewise, no significant change was noted due to irradiation in the functional properties of rice such as swelling index and water absorption and in total volatile components responsible for flavour of Basmati rice. In organoleptic evaluation, no significant difference was found between the acceptability of irradiated (0.25 kGy) and control rice. These results are significant in view of the high export potential of Basmati rice and the transit losses at present due to infestation. (author). 24 refs., 5 tabs., 1 fig
Cytoplasmic-genetic male sterility gene provides direct evidence for some hybrid rice recently evolving into weedy rice

Science.gov (United States)

Zhang, Jingxu; Lu, Zuomei; Dai, Weimin; Song, Xiaoling; Peng, Yufa; Valverde, Bernal E.; Qiang, Sheng

2015-01-01

Weedy rice infests paddy fields worldwide at an alarmingly increasing rate. There is substantial evidence indicating that many weedy rice forms originated from or are closely related to cultivated rice. There is suspicion that the outbreak of weedy rice in China may be related to widely grown hybrid rice due to its heterosis and the diversity of its progeny, but this notion remains unsupported by direct evidence. We screened weedy rice accessions by both genetic and molecular marker tests for the cytoplasmic male sterility (CMS) genes (Wild abortive, WA, and Boro type, BT) most widely used in the production of indica and japonica three-line hybrid rice as a diagnostic trait of direct parenthood. Sixteen weedy rice accessions of the 358 tested (4.5%) contained the CMS-WA gene; none contained the CMS-BT gene. These 16 accessions represent weedy rices recently evolved from maternal hybrid rice derivatives, given the primarily maternal inheritance of this trait. Our results provide key direct evidence that hybrid rice can be involved in the evolution of some weedy rice accessions, but is not a primary factor in the recent outbreak of weedy rice in China. PMID:26012494
Cytoplasmic-genetic male sterility gene provides direct evidence for some hybrid rice recently evolving into weedy rice.

Science.gov (United States)

Zhang, Jingxu; Lu, Zuomei; Dai, Weimin; Song, Xiaoling; Peng, Yufa; Valverde, Bernal E; Qiang, Sheng

2015-05-27

Weedy rice infests paddy fields worldwide at an alarmingly increasing rate. There is substantial evidence indicating that many weedy rice forms originated from or are closely related to cultivated rice. There is suspicion that the outbreak of weedy rice in China may be related to widely grown hybrid rice due to its heterosis and the diversity of its progeny, but this notion remains unsupported by direct evidence. We screened weedy rice accessions by both genetic and molecular marker tests for the cytoplasmic male sterility (CMS) genes (Wild abortive, WA, and Boro type, BT) most widely used in the production of indica and japonica three-line hybrid rice as a diagnostic trait of direct parenthood. Sixteen weedy rice accessions of the 358 tested (4.5%) contained the CMS-WA gene; none contained the CMS-BT gene. These 16 accessions represent weedy rices recently evolved from maternal hybrid rice derivatives, given the primarily maternal inheritance of this trait. Our results provide key direct evidence that hybrid rice can be involved in the evolution of some weedy rice accessions, but is not a primary factor in the recent outbreak of weedy rice in China.
In Vitro Iron Bioavailability of Brazilian Food-Based by-Products.

Science.gov (United States)

Chiocchetti, Gabriela M; De Nadai Fernandes, Elisabete A; Wawer, Anna A; Fairweather-Tait, Susan; Christides, Tatiana

2018-05-16

Background : Iron deficiency is a public health problem in many low- and middle-income countries. Introduction of agro-industrial food by-products, as additional source of nutrients, could help alleviate this micronutrient deficiency, provide alternative sources of nutrients and calories in developed countries, and be a partial solution for disposal of agro-industry by-products. Methods : The aim of this study was to determine iron bioavailability of 5 by-products from Brazilian agro-industry (peels from cucumber, pumpkin, and jackfruit, cupuaçu seed peel, and rice bran), using the in vitro digestion/ Caco-2 cell model; with Caco-2 cell ferritin formation as a surrogate marker of iron bioavailability. Total and dialyzable Fe, macronutrients, the concentrations of iron-uptake inhibitors (phytic acid, tannins, fiber) and their correlation with iron bioavailability were also evaluated. Results : The iron content of all by-products was high, but the concentration of iron and predicted bioavailability were not related. Rice bran and cupuaçu seed peel had the highest amount of phytic acid and tannins, and lowest iron bioavailability. Cucumber peels alone, and with added extrinsic Fe, and pumpkin peels with extrinsic added iron, had the highest iron bioavailability. Conclusion : The results suggest that cucumber and pumpkin peel could be valuable alternative sources of bioavailable Fe to reduce iron deficiency in at-risk populations.
Asian wild rice is a hybrid swarm with extensive gene flow and feralization from domesticated rice

OpenAIRE

Wang, Hongru; Garrett Vieira, Filipe Jorge; Crawford, Jacob E.; Chu, Chengcai; Nielsen, Rasmus

2017-01-01

The domestication history of rice remains controversial, with multiple studies reaching different conclusions regarding its origin(s). These studies have generally assumed that populations of living wild rice, O. rufipogon, are descendants of the ancestral population that gave rise to domesticated rice, but relatively little attention has been paid to the origins and history of wild rice itself. Here, we investigate the genetic ancestry of wild rice by analyzing a diverse panel of rice genome...
Publication in a Brazilian journal by Brazilian scientists whose papers have international impact.

Science.gov (United States)

Meneghini, R

2010-09-01

Nine Brazilian scientists with an outstanding profile of international publications were invited to publish an original article in the same issue of a Brazilian Journal (Anais da Academia Brasileira de Ciências). The objective was to measure the impact of the papers on the number of citations to the articles, the assumption being that these authors would carry their international prestige to the Brazilian periodical. In a 2-year period there was a larger number of citations of these articles compared to others published in the same journal. Nevertheless, the number of citations in Brazilian journals did not equal the number of citations obtained by the other papers by the same authors in their international publications within the same 2-year period. The reasons for this difference in the number of citations could be either that less significant invited articles were submitted or that it was due to the intrinsic lack of visibility of the Brazilian journals, but this could not be fully determined with the present data. Also relevant was a comparison between the citations of Brazilian journals and the publication in Brazilian journals by these selected authors. A clear imbalance due to a remarkable under-citation of Brazilian authors by authors publishing in Brazilian journals raises the possibility that psychological factors may affect the decision of citing Brazilian journals.
Rice mutants obtained through sodium azide (NaN3) treatment

International Nuclear Information System (INIS)

Silva, E.F.; Ando, A.; Tulmann Neto, A.

2001-01-01

The successful utilization of sodium azide to generate genetic variability in plant breeding has been reported in barley, rice, and other crops. Rice seeds of 'Dourado Precoce', Brazilian upland cultivar, were treated with 5x10 -3 M of sodium azide, prepared in buffer solution of pH 3,0, for 8 hours at laboratory temperature. Ten short culm mutant lines were selected in the M 2 , M 3 and M 4 generations. In the M 5 generation, the mutant lines were evaluated for flowering and maturing cycles, tiller number per plant, plant height, panicle number per m 2 , panicle length, fertility of panicle, weight of 1.000 grains, productivity, percentage of intact grains after milling, width and thickness of peeled and polished grains and length/width grain ratio. The experiment was conducted in the Centro Experimental of Instituto Agronomico, Campinas, Sao Paulo, Brazil, during the period of 1993/94, utilizing randomized block design with four replications. Each experimental plot consisted of five rows of four meters in length, 50 cm between rows, with 75 seeds sown per meter. The cultivar 'IAC 201' and the original Dourado Precoce were planted as checks. All observations were made on the three central rows of each experimental plot. The data was analysed by the SANEST statistical program and the mean values were discriminated by the Tukey's test at the level 5% of probability

Metal-silica sol-gel materials

Science.gov (United States)

Stiegman, Albert E. (Inventor)

2002-01-01

The present invention relates to a single phase metal-silica sol-gel glass formed by the co-condensation of a transition metal with silicon atoms where the metal atoms are uniformly distributed within the sol-gel glass as individual metal centers. Any transition metal may be used in the sol-gel glasses. The present invention also relates to sensor materials where the sensor material is formed using the single phase metal-silica sol-gel glasses. The sensor materials may be in the form of a thin film or may be attached to an optical fiber. The present invention also relates to a method of sensing chemicals using the chemical sensors by monitoring the chromatic change of the metal-silica sol-gel glass when the chemical binds to the sensor. The present invention also relates to oxidation catalysts where a metal-silica sol-gel glass catalyzes the reaction. The present invention also relates to a method of performing oxidation reactions using the metal-silica sol-gel glasses. The present invention also relates to organopolymer metal-silica sol-gel composites where the pores of the metal-silica sol-gel glasses are filled with an organic polymer polymerized by the sol-gel glass.
An intensified esterification process of palm oil fatty acid distillate catalyzed by delipidated rice bran lipase.

Science.gov (United States)

Chong, Fui Chin; Tey, Beng Ti; Dom, Zanariah Mohd; Ibrahim, Nordin; Rahman, Russly Abd; Ling, Tau Chuan

2006-09-07

An intensified esterification process was operated by circulating 10 l of reaction mixtures, consisting of palm oil fatty acid distillate (PFAD) and glycerol in hexane, through a packed-bed reactor (PBR) filled with 10 kg of delipidated rice bran lipase (RBL). The influence of the process parameters, such as reaction temperature and type of water-removal agent, on the performance of this intensified esterification process were investigated. The highest degree of esterification (61%) was achieved at a reaction temperature of 65 masculineC, using silica gels as the water-removal agent. Thin-layer chromatography (TLC) analysis showed that the major composition of the esterified product was diacylglycerol.
An Intensified Esterification Process of Palm Oil Fatty Acid Distillate Catalyzed by Delipidated Rice Bran Lipase

Directory of Open Access Journals (Sweden)

Fui Chin Chong

2006-01-01

Full Text Available An intensified esterification process was operated by circulating 10 l of reaction mixtures, consisting of palm oil fatty acid distillate (PFAD and glycerol in hexane, through a packed-bed reactor (PBR filled with 10 kg of delipidated rice bran lipase (RBL. The influence of the process parameters, such as reaction temperature and type of water-removal agent, on the performance of this intensified esterification process were investigated. The highest degree of esterification (61% was achieved at a reaction temperature of 65°C, using silica gels as the water-removal agent. Thin-layer chromatography (TLC analysis showed that the major composition of the esterified product was diacylglycerol.
Transcriptional changes of rice in response to rice black-streaked dwarf virus.

Science.gov (United States)

Ahmed, Mohamed M S; Ji, Wen; Wang, Muyue; Bian, Shiquan; Xu, Meng; Wang, Weiyun; Zhang, Jiangxiang; Xu, Zhihao; Yu, Meimei; Liu, Qiaoquan; Zhang, Changquan; Zhang, Honggen; Tang, Shuzhu; Gu, Minghong; Yu, Hengxiu

2017-09-10

Rice black-streaked dwarf virus (RBSDV), a member of the genus Fijivirus in the family Reoviridae, causes significant economic losses in rice production in China and many other Asian countries. Although a great deal of effort has been made to elucidate the interactions among the virus, insect vectors, host and environmental conditions, few RBSDV proteins involved in pathogenesis have been identified, and the biological basis of disease development in rice remains largely unknown. Transcriptomic information associated with the disease development in rice would be helpful to unravel the biological mechanism. To determine how the rice transcriptome changes in response to RBSDV infection, we carried out RNA-Seq to perform a genome-wide gene expression analysis of a susceptible rice cultivar KTWYJ3. The transcriptomes of RBSDV-infected samples were compared to those of RBSDV-free (healthy) at two time points (time points are represented by group I and II). The results derived from the differential expression analysis in RBSDV-infected libraries vs. healthy ones in group I revealed that 102 out of a total of 281 significant differentially expressed genes (DEGs) were up-regulated and 179 DEGs were down-regulated. Of the 2592 identified DEGs in group II, 1588 DEGs were up-regulated and 1004 DEGs were down-regulated. A total of 66 DEGs were commonly identified in both groups. Of these 66 DEGs, expression patterns for 36 DEGs were similar in both groups. Our analysis demonstrated that some genes related to disease defense and stress resistance were up-regulated while genes associated with chloroplast were down-regulated in response to RBSDV infection. In addition, some genes associated with plant-height were differentially expressed. This result indicates those genes might be involved in dwarf symptoms caused by RBSDV. Taken together, our results provide a genome-wide transcriptome analysis for rice plants in response to RBSDV infection which may contribute to the
Integrated rice-duck farming mitigates the global warming potential in rice season.

Science.gov (United States)

Xu, Guochun; Liu, Xin; Wang, Qiangsheng; Yu, Xichen; Hang, Yuhao

2017-01-01

Integrated rice-duck farming (IRDF), as a mode of ecological agriculture, is an important way to realize sustainable development of agriculture. A 2-year split-plot field experiment was performed to evaluate the effects of IRDF on methane (CH 4 ) and nitrous oxide (N 2 O) emissions and its ecological mechanism in rice season. This experiment was conducted with two rice farming systems (FS) of IRDF and conventional farming (CF) under four paddy-upland rotation systems (PUR): rice-fallow (RF), annual straw incorporating in rice-wheat rotation system (RWS), annual straw-based biogas residues incorporating in rice-wheat rotation system (RWB), and rice-green manure (RGM). During the rice growing seasons, IRDF decreased the CH 4 emission by 8.80-16.68%, while increased the N 2 O emission by 4.23-15.20%, when compared to CF. Given that CH 4 emission contributed to 85.83-96.22% of global warming potential (GWP), the strong reduction in CH 4 emission led to a significantly lower GWP of IRDF as compared to CF. The reason for this trend was because IRDF has significant effect on dissolved oxygen (DO) and soil redox potential (Eh), which were two pivotal factors for CH 4 and N 2 O emissions in this study. The IRDF not only mitigates the GWP, but also increases the rice yield by 0.76-2.43% compared to CF. Moreover, compared to RWS system, RF, RWB and RGM systems significantly reduced CH 4 emission by 50.17%, 44.89% and 39.51%, respectively, while increased N 2 O emission by 10.58%, 14.60% and 23.90%, respectively. And RWS system had the highest GWP. These findings suggest that mitigating GWP and improving rice yield could be simultaneously achieved by the IRDF, and employing suitable PUR would benefit for relieving greenhouse effect. Copyright © 2016 Elsevier B.V. All rights reserved.
Engineered Dwarf Male-Sterile Rice: A Promising Genetic Tool for Facilitating Recurrent Selection in Rice.

Science.gov (United States)

Ansari, Afsana; Wang, Chunlian; Wang, Jian; Wang, Fujun; Liu, Piqing; Gao, Ying; Tang, Yongchao; Zhao, Kaijun

2017-01-01

Rice is a crop feeding half of the world's population. With the continuous raise of yield potential via genetic improvement, rice breeding has entered an era where multiple genes conferring complex traits must be efficiently manipulated to increase rice yield further. Recurrent selection is a sound strategy for manipulating multiple genes and it has been successfully performed in allogamous crops. However, the difficulties in emasculation and hand pollination had obstructed efficient use of recurrent selection in autogamous rice. Here, we report development of the dwarf male-sterile rice that can facilitate recurrent selection in rice breeding. We adopted RNAi technology to synergistically regulate rice plant height and male fertility to create the dwarf male-sterile rice. The RNAi construct pTCK-EGGE, targeting the OsGA20ox2 and OsEAT1 genes, was constructed and used to transform rice via Agrobacterium -mediated transformation. The transgenic T0 plants showing largely reduced plant height and complete male-sterile phenotypes were designated as the dwarf male-sterile plants. Progenies of the dwarf male-sterile plants were obtained by pollinating them with pollens from the wild-type. In the T1 and T2 populations, half of the plants were still dwarf male-sterile; the other half displayed normal plant height and male fertility which were designated as tall and male-fertile plants. The tall and male-fertile plants are transgene-free and can be self-pollinated to generate new varieties. Since emasculation and hand pollination for dwarf male-sterile rice plants is no longer needed, the dwarf male-sterile rice can be used to perform recurrent selection in rice. A dwarf male-sterile rice-based recurrent selection model has been proposed.
Silica aerogel Cerenkov counter

International Nuclear Information System (INIS)

Yasumi, S.; Masaike, A.; Yamamoto, A.; Yoshimura, Y.; Kawai, H.

1984-03-01

In order to obtain silica aerogel radiators of good quality, the prescription used by Saclay group has been developed. We have done several experiments using beams from KEK.PS to test the performance of a Cerenkov counter with aerogel modules produced in KEK. It turned out that these modules had excellent quality. The production rate of silica aerogel in KEK is 15 -- 20 litres a week. Silica aerogel modules of 20 x 10 x 3 cm 3 having the refractive index of 1.058 are successfully being used by Kyoto University group in the KEK experiment E92 (Σ). Methodes to produce silica aerogel with higher refractive index than 1.06 has been investigated both by heating an module with the refractive index of 1.06 and by hydrolyzing tetraethyl silicate. (author)
Melt flow and mechanical properties of silica/perfluoropolymer nanocomposites Fabricated by direct melt-compounding without surface modification on nano-silica.

Science.gov (United States)

Tanahashi, Mitsuru; Watanabe, Yusuke; Lee, Jeong-Chang; Takeda, Kunihiko; Fujisawa, Toshiharu

2009-01-01

The authors have previously developed a novel method for the fabrication of silica/perfluoropolymer nanocomposites, wherein nano-sized silica particles without surface modification were dispersed uniformly through breakdown of loosely packed agglomerates of silica nanoparticles with low fracture strength in a polymer melt during direct melt-compounding. The method consists of two stages; the first stage involves preparation of the loose silica agglomerate, and the second stage involves melt-compounding of a completely hydrophobic perfluoropolymer, PFA (poly(tetrafluoroethylene-co-perfluoropropylvinylether)), with the loose silica agglomerates. By using this simple method without any lipophilic treatment of the silica surfaces, silica nanoparticles with a primary diameter of 190 nm could be dispersed uniformly into the PFA matrix. The main purpose of the present study is to evaluate the melt flow and tensile properties of silica/PFA nanocomposites fabricated by the above method. In order to elucidate the effects of the size of the dispersed silica in the PFA matrix on the properties of the composites, silica/PFA composite samples exhibiting the dispersion of larger-sized silica particle-clusters were fabricated as negative controls of the silica dispersion state. The results obtained under the present experimental conditions showed that the size of the dispersed silica in the PFA matrix exerts a strong influence on the ultimate tensile properties, such as tensile strength and elongation at break, and the melt flow rate (MFR) of the composite materials. The MFR of the silica/PFA nanocomposite became higher than that of the pure PFA without silica addition, although the MFR of the PFA composites containing larger silica particle-clusters became much lower than that of the pure PFA. Furthermore, uniform dispersion of isolated silica nanoparticles was found to improve not only the Young's modulus but also the ultimate tensile properties of the composite.
Multifunctional nanomedicine with silica: Role of silica in nanoparticles for theranostic, imaging, and drug monitoring.

Science.gov (United States)

Chen, Fang; Hableel, Ghanim; Zhao, Eric Ruike; Jokerst, Jesse V

2018-07-01

The idea of multifunctional nanomedicine that enters the human body to diagnose and treat disease without major surgery is a long-standing dream of nanomaterials scientists. Nanomaterials show incredible properties that are not found in bulk materials, but achieving multi-functionality on a single material remains challenging. Integrating several types of materials at the nano-scale is critical to the success of multifunctional nanomedicine device. Here, we describe the advantages of silica nanoparticles as a tool for multifunctional nano-devices. Silica nanoparticles have been intensively studied in drug delivery due to their biocompatibility, degradability, tunable morphology, and ease of modification. Moreover, silica nanoparticles can be integrated with other materials to obtain more features and achieve theranostic capabilities and multimodality for imaging applications. In this review, we will first compare the properties of silica nanoparticles with other well-known nanomaterials for bio-applications and describe typical routes to synthesize and integrate silica nanoparticles. We will then highlight theranostic and multimodal imaging application that use silica-based nanoparticles with a particular interest in real-time monitoring of therapeutic molecules. Finally, we will present the challenges and perspective on future work with silica-based nanoparticles in medicine. Copyright © 2018 Elsevier Inc. All rights reserved.
Labor and Employment in Brazilian Northeastern Agriculture: a look at the 2004-2014 period

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Otavio Valentim Balsadi

Full Text Available Abstract: The labor market in the Brazilian Northeastern agriculture is characterized by many forms of occupation, ranging from the salaried work to the various forms of family work. In a heterogeneous and diverse agriculture, there is a complex labor market, with changes in recent times. Therefore, it is necessary to keep a watchful eye on important structural features. As a result, this paper aims to analyze the main aspects related to work and employment relations in the Brazilian Northeastern agriculture in the 2004-2014 period. The sources of information are special tabulations from the National Survey by Household Sample (PNAD, conducted by the Brazilian Institute of Geography and Statistics (IBGE. The results pointed to a continuing decline in Northeastern PEA (Economically Active Population occupied in agriculture, partially offset by the growth of Northeastern rural residents occupied in non-agricultural activities, in addition to the people occupied in self-consumption production. Women and young people were the ones who mostly left the agricultural activities, reinforcing the “ageing” process of the occupied PEA. The crops with the largest reduction in the occupied in agricultural PEA were: cassava, rice, coffee, banana, sugarcane, cocoa, vegetables and fruits. On the other hand, the number of occupied people increased in: corn and grape cultivation, services for agriculture, swine and poultry farming and integrated agricultural and livestock production systems. An increase in schooling of the occupied PEA was registered, though it is still below the national average.
Study of the pluronic-silica interaction in synthesis of mesoporous silica under mild acidic conditions.

Science.gov (United States)

Sundblom, Andreas; Palmqvist, Anders E C; Holmberg, Krister

2010-02-02

The interaction between silica and poly(ethylene oxide) (PEO) in water may appear trivial and it is generally stated that hydrogen bonding is responsible for the attraction. However, a literature search shows that there is not a consensus with respect to the mechanism behind the attractive interaction. Several papers claim that only hydrogen bonding is not sufficient to explain the binding. The silica-PEO interaction is interesting from an academic perspective and it is also exploited in the preparation of mesoporous silica, a material of considerable current interest. This study concerns the very early stage of synthesis of mesoporous silica under mild acidic conditions, pH 2-5, and the aim is to shed light on the interaction between silica and the PEO-containing structure directing agent. The synthesis comprises two steps. An organic silica source, tetraethylorthosilicate (TEOS), is first hydrolyzed and Pluronic P123, a poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) block copolymer, is subsequently added at different time periods following the hydrolysis of TEOS. It is shown that the interaction between the silica and the Pluronic is dependent both on the temperature and on the time between onset of TEOS hydrolysis and addition of the copolymer. The results show that the interaction is mainly driven by entropy. The effect of the synthesis temperature and of the time between hydrolysis and addition of the copolymer on the final material is also studied. The material with the highest degree of mesoorder was obtained when the reaction was performed at 20 degrees C and the copolymer was added 40 h after the start of TEOS hydrolysis. It is claimed that the reason for the good ordering of the silica is that whereas particle formation under these conditions is fast, the rate of silica condensation is relatively low.
75 FR 56911 - Request for Public Comment on the United States Standards for Rough Rice, Brown Rice for...

Science.gov (United States)

2010-09-17

... for Rough Rice, Brown Rice for Processing, and Milled Rice AGENCY: Grain Inspection, Packers and... reviewing the United States Standards and grading procedures for Rough Rice, Brown Rice for Processing, and Milled Rice under the Agriculture Marketing Act of 1946 (AMA). Since the standards were last revised...
Silica coatings on clarithromycin.

Science.gov (United States)

Bele, Marjan; Dmitrasinovic, Dorde; Planinsek, Odon; Salobir, Mateja; Srcic, Stane; Gaberscek, Miran; Jamnik, Janko

2005-03-03

Pre-crystallized clarithromycin (6-O-methylerythromycin A) particles were coated with silica from the tetraethyl orthosilicate (TEOS)-ethanol-aqueous ammonia system. The coatings had a typical thickness of 100-150 nm and presented about 15 wt.% of the silica-drug composite material. The properties of the coatings depended on reactant concentration, temperature and mixing rate and, in particular, on the presence of a cationic surfactant (cetylpyridinium chloride). In the presence of cetylpyridinium chloride the silica coatings slightly decreased the rate of pure clarithromycin dissolution.
Oxygen configurations in silica

International Nuclear Information System (INIS)

Chelikowsky, James R.; Chadi, D. J.; Binggeli, N.

2000-01-01

We propose a transition state for oxygen in silica. This state is produced by the insertion of an oxygen molecule into the Si-O-Si bond, i.e., it consists of producing a Si-O-O-O-Si bond. This state allows molecular oxygen diffusion in silica without breaking the molecular O 2 bond and it is energetically more stable than a peroxy configuration. This configuration may allow for exchange of molecular oxygen with the oxygen in the silica framework. (c) 2000 The American Physical Society
Rice as commodity and anti-commodity

NARCIS (Netherlands)

Richards, P.

2016-01-01

On the Upper West Africa coast rice belongs to two species — African rice (Oryza glaberrima Steud.) and Asian rice (Oryza sativa L.). African rice was domesticated in the region, perhaps three millennia ago, from a presumed wild ancestor, O. barthii. Asian rice was introduced via trans-Saharan
The Effect of Various Acids to the Gelation Process to the Silica Gel Characteristic Using Organic Silica

Science.gov (United States)

Rahman, NA; Widiyastuti, W.; Sigit, D.; Ajiza, M.; Sujana, W.

2018-01-01

Bagasse ash is solid waste of cane sugar industry which contain of silica more than 51%. Some previous study of silica gel from bagasse ash have been conducted often and been applied. This study concerns about the effect of various acid used in the process of gelation to the characteristic of silica gel produced. Then, this silica gel will be used as adsorbent. As that, the silica gel must fulfill the requirements of adsorbent, as have good pores characteristics, fit in mesoporous size so that adsorbent diffusion process is not disturbed. A fitted pores size of silica gel can be prepared by managing acid concentration used. The effect of acid, organic acid (tartaric acid) and inorganic acid (hydrochloric acid), is investigated in detail. The acid is added into sodium silicate solution in that the gel is formed, the pores structures can be investigated with BET, the crystal form is analyzed with XRD and the pore structure is analyzed visually with SEM. By managing the acid concentration added, it gets the effect of acid to the pore structure of silica gel. The bigger concentration is, the bigger the pore’s size of silica gel produced.
Processing and characterization of extruded breakfast meal formulated with broken rice and bean flour

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Ana Vânia Carvalho

2012-09-01

Full Text Available The objective of this work was to develop an extruded breakfast product containing broken rice and split old beans and to verify the influence of the extrusion process on their physicochemical, technological, and sensory characteristic. The final product had a protein content of 9.9 g.100 g-1, and therefore it can be considered a good source of proteins for children and teenagers. The dietary fiber content of the final edible product was 3.71 g.100 g-1. Therefore, the breakfast meal may be considered as a source of dietary fiber according to Brazilian law . As for the technological properties, the extruded product presented an expansion index of 8.89 and apparent density of 0.25 g.cm-3. With regard to the sensory analysis, the acceptance average was ranked between 6.8 and 7.7, corresponding to the categories "liked slightly" and "liked very much". With regard to purchase intention, 79% of the panelists said they would certainly or possibly purchase the product. Broken rice and split old beans are interesting alternatives for the elaboration of extruded breakfast products presenting good nutritional, technological, and sensory qualities.
Rice hull/MnFe2O4 composite: Preparation, characterization and its rapid microwave-assisted COD removal for organic wastewater

International Nuclear Information System (INIS)

Lv Shuangshuang; Chen Xuegang; Ye Ying; Yin Suhang; Cheng Jipeng; Xia Meisheng

2009-01-01

Adsorbent/ferrite composites can adsorb and degrade organics in the organic wastewater treatment. In this study, a rice hull/MnFe 2 O 4 composite (RHM) was prepared via calcination under nitrogen atmosphere and was used to treat organic wastewater with the assistance of microwave radiation. Rice hull was pyrolysed to a porous substrate that consisted of silica and activated carbon under high temperature. Monodisperse spinel MnFe 2 O 4 nanoparticles whose mean diameter is around 59 nm are distributed on the substrate. With the assistance of microwave radiation, RHM was motivated to a hotspot of adsorption and catalysis which could remove more than 70% COD of wastewater within 6 min. The maximum COD removal was 73.5% when the concentration of RHM was 15 mg mL -1 and the irradiation time of microwave radiation was 6 min. Although the BET surface area and iodine value of RHM are half of rice hull ash (RHA), the COD removal of RHM is 7-20% higher than that of RHA. It is attributed to the presence of MnFe 2 O 4 , which enhances the catalytic activity of RHM. RHM can be regenerated via water washing. However, the surface area and the maximum COD removal of RHM decrease for each regeneration cycle. With the advantages of low cost and rapid processing, this novel rice hull/MnFe 2 O 4 composite could gain promising application in wastewater treating-agent.
RICD: A rice indica cDNA database resource for rice functional genomics

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Zhang Qifa

2008-11-01

Full Text Available Abstract Background The Oryza sativa L. indica subspecies is the most widely cultivated rice. During the last few years, we have collected over 20,000 putative full-length cDNAs and over 40,000 ESTs isolated from various cDNA libraries of two indica varieties Guangluai 4 and Minghui 63. A database of the rice indica cDNAs was therefore built to provide a comprehensive web data source for searching and retrieving the indica cDNA clones. Results Rice Indica cDNA Database (RICD is an online MySQL-PHP driven database with a user-friendly web interface. It allows investigators to query the cDNA clones by keyword, genome position, nucleotide or protein sequence, and putative function. It also provides a series of information, including sequences, protein domain annotations, similarity search results, SNPs and InDels information, and hyperlinks to gene annotation in both The Rice Annotation Project Database (RAP-DB and The TIGR Rice Genome Annotation Resource, expression atlas in RiceGE and variation report in Gramene of each cDNA. Conclusion The online rice indica cDNA database provides cDNA resource with comprehensive information to researchers for functional analysis of indica subspecies and for comparative genomics. The RICD database is available through our website http://www.ncgr.ac.cn/ricd.
Physicochemical and Antioxidant Properties of Rice Bran Oils Produced from Colored Rice Using Different Extraction Methods.

Science.gov (United States)

Mingyai, Sukanya; Kettawan, Aikkarach; Srikaeo, Khongsak; Singanusong, Riantong

2017-06-01

This study investigated the physicochemical and antioxidant properties of rice bran oil (RBO) produced from the bran of three rice varities; Khao Dawk Mali 105 (white rice), Red Jasmine rice (red rice) and Hom-nin rice (black rice) using three extraction methods including cold-press extraction (CPE), solvent extraction (SE) and supercritical CO 2 extraction (SC-CO 2 ). Yields, color, acid value (AV), free fatty acid (FFA), peroxide value (PV), iodine value (IV), total phenolic compound (TPC), γ-oryzanol, α-tocopherol and fatty acid profile were analyzed. It was found that the yields obtained from SE, SC-CO 2 and CPE extractions were 17.35-20.19%, 14.76-18.16% and 3.22-6.22%, respectively. The RBO from the bran of red and black rice samples exhibited high antioxidant activities. They also contained higher amount of γ-oryzanol and α-tocopherol than those of white rice sample. In terms of extraction methods, SC-CO 2 provided better qualities of RBO as evidenced by their physicochemical and antioxidant properties. This study found that RBO produced from the bran of black rice samples using SC-CO 2 extraction method showed the best physicochemical and antioxidant properties.

Dynamic viscoelasticity of protease-treated rice batters for gluten-free rice bread making.

Science.gov (United States)

Honda, Yuji; Inoue, Nanami; Sugimoto, Reina; Matsumoto, Kenji; Koda, Tomonori; Nishioka, Akihiro

2018-03-01

Papain (cysteine protease), subtilisin (Protin SD-AY10, serine protease), and bacillolysin (Protin SD-NY10, metallo protease) increased the specific volume of gluten-free rice breads by 19-63% compared to untreated bread. In contrast, Newlase F (aspartyl protease) did not expand the volume of the rice bread. In a rheological analysis, the viscoelastic properties of the gluten-free rice batters also depended on the protease categories. Principal component analysis (PCA) analysis suggested that the storage and loss moduli (G' and G″, respectively) at 35 °C, and the maximum values of G' and G″, were important factors in the volume expansion. Judging from the PCA of the viscoelastic parameters of the rice batters, papain and Protin SD-AY10 improved the viscoelasticity for gluten-free rice bread making, and Protin SD-NY effectively expanded the gluten-free rice bread. The rheological properties differed between Protin SD-NY and the other protease treatments.
Preparation and characterization of hybrid Nafion/silica and Nafion/silica/PTA membranes for redox flow batteries

Energy Technology Data Exchange (ETDEWEB)

Glibin, V.; Pupkevich, V.; Svirko, L.; Karamanev, D. [Western Ontario Univ., London, ON (Canada). Dept. of Biochemical and Chemical Engineering

2008-07-01

Redox flow batteries are both efficient and cost-effective. However, the long-term stability of most ion-exchange membranes is limited as a result of the high oxidation rates of ions with high redox potentials. A method of synthesizing multi-component Nafion-silica and Nafion-silica-PTA membranes was presented in this study, which also investigated the electrochemical and ion transport properties of the membranes. Membranes were cast from dimethylformamide (DMFA) solution. The iron ion diffusion kinetics of the Nafion-silica and Nafion-silica PTA membranes were studied by dialysis. Results of the investigation demonstrated that the introduction of silica and phosphotungstic acid (PTA) into the Nafion membrane composition resulted in a significant decrease of ion transfer through the membrane. The addition of PTA also increased membrane permeability to ferric ions. The low iron diffusion coefficient and high ionic conductivity of the Nafion-silica membrane makes it a promising material for use in redox flow batteries. 4 refs., 1 tab., 1 fig.
Silica-Coated Liposomes for Insulin Delivery

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Neelam Dwivedi

2010-01-01

Full Text Available Liposomes coated with silica were explored as protein delivery vehicles for their enhanced stability and improved encapsulation efficiency. Insulin was encapsulated within the fluidic phosphatidylcholine lipid vesicles by thin film hydration at pH 2.5, and layer of silica was formed above lipid bilayer by acid catalysis. The presence of silica coating and encapsulated insulin was identified using confocal and electron microscopy. The native state of insulin present in the formulation was evident from Confocal Micro-Raman spectroscopy. Silica coat enhances the stability of insulin-loaded delivery vehicles. In vivo study shows that these silica coated formulations were biologically active in reducing glucose levels.
Characterization of Volatile Flavor Compounds in Chinese Rice Wine Fermented from Enzymatic Extruded Rice.

Science.gov (United States)

Xu, Enbo; Long, Jie; Wu, Zhengzong; Li, Hongyan; Wang, Fang; Xu, Xueming; Jin, Zhengyu; Jiao, Aiquan

2015-07-01

Enzymatic extrusion, instead of traditional steam cooking, to treat rice is an efficient and alternative pretreatment for Chinese rice wine fermentation. In order to determine the formation of volatiles in enzymatic extrusion-processed rice wine (EE), and to confirm its characteristic flavor compounds, headspace solid-phase micro-extraction followed by GC-MS was used. A total of 66 volatile compounds were identified in EE. During fermentation, most volatiles generated from enzymatic extruded rice had the similar trends with those from steam-cooked rice, but the differences in the concentration of volatiles indicated a changed balance of flavors release caused by enzymatic extrusion. Besides, the concentrations and sorts of volatiles in EEs fermented from different rice particle sizes, were not dramatically different. By principal component analysis, EE could be distinctly separated from other traditional Chinese rice wines according to its characteristic volatiles, namely, 2-heptanol, 1-octen-3-ol, ethyl 4-hydroxybenzoate, methylpentyl 2-propenoate, γ-hexalactone, and 4-vinylguaiacol. Enzymatic extrusion liquefaction has been a popular thermal treatment for cereals, and gradually being applied in fermentation and liquor-making industry all over the world. The characterization of volatile flavor compounds in Chinese rice wine processed by enzymatic extrusion liquefaction pretreatment, might be made use not only for a better understanding of this new-type rice wine, but for the further utilization of enzymatic extrusion in other wine or alcohol production as well. © 2015 Institute of Food Technologists®
Silica artificial opal incorporated with silver nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Li Wenjiang, E-mail: wjli@zju.edu.cn [Center for Optical and Electromagnetic Research, State Key Laboratory for Modern Optical Instrumentation, Zhejiang University, Joint Research Center of Photonics of the Royal Institute of Technology and Zhejiang University, Zijingang Campus, Room 210, East Building 5, Hangzhou 310058 (China); Sun Tan [Center for Optical and Electromagnetic Research, State Key Laboratory for Modern Optical Instrumentation, Zhejiang University, Joint Research Center of Photonics of the Royal Institute of Technology and Zhejiang University, Zijingang Campus, Room 210, East Building 5, Hangzhou 310058 (China)

2009-07-15

The silica artificial opal with a three-dimensional (3D) periodic structure was prepared using highly monodispersed silica microspheres by a force packing method in ITO glass cell. The silica artificial opal incorporated with silver nanoparticles was fabricated by the electroplating technique. The optical microscope images of the synthetic sample and the corresponding optical properties were measured after each treatment of electroplating-washing-drying circle. The transmission and reflection spectra presented a red shift, showing that the effective refractive index of the complex silver/silica opal increased after each electroplating. Combining the SEM images, it was seen that the silver nanoparticles could be directly deposited on the surface of silica spheres in the opaline structure. The silver/silica complex opal film could provide a simple way to tune the opal properties by controlling silver nanoparticles in the silica opal. The silver/silica opal crystal structures could be used for nano-photonic circuits, white-light LEDs or as photocatalysts.
Silica artificial opal incorporated with silver nanoparticles

International Nuclear Information System (INIS)

Li Wenjiang; Sun Tan

2009-01-01

The silica artificial opal with a three-dimensional (3D) periodic structure was prepared using highly monodispersed silica microspheres by a force packing method in ITO glass cell. The silica artificial opal incorporated with silver nanoparticles was fabricated by the electroplating technique. The optical microscope images of the synthetic sample and the corresponding optical properties were measured after each treatment of electroplating-washing-drying circle. The transmission and reflection spectra presented a red shift, showing that the effective refractive index of the complex silver/silica opal increased after each electroplating. Combining the SEM images, it was seen that the silver nanoparticles could be directly deposited on the surface of silica spheres in the opaline structure. The silver/silica complex opal film could provide a simple way to tune the opal properties by controlling silver nanoparticles in the silica opal. The silver/silica opal crystal structures could be used for nano-photonic circuits, white-light LEDs or as photocatalysts.
Silica nanoparticle stability in biological media revisited.

Science.gov (United States)

Yang, Seon-Ah; Choi, Sungmoon; Jeon, Seon Mi; Yu, Junhua

2018-01-09

The stability of silica nanostructure in the core-silica shell nanomaterials is critical to understanding the activity of these nanomaterials since the exposure of core materials due to the poor stability of silica may cause misinterpretation of experiments, but unfortunately reports on the stability of silica have been inconsistent. Here, we show that luminescent silver nanodots (AgNDs) can be used to monitor the stability of silica nanostructures. Though relatively stable in water and phosphate buffered saline, silica nanoparticles are eroded by biological media, leading to the exposure of AgNDs from AgND@SiO 2 nanoparticles and the quenching of nanodot luminescence. Our results reveal that a synergistic effect of organic compounds, particularly the amino groups, accelerates the erosion. Our work indicates that silica nanostructures are vulnerable to cellular medium and it may be possible to tune the release of drug molecules from silica-based drug delivery vehicles through controlled erosion.
Thermally stable silica-coated hydrophobic gold nanoparticles.

Science.gov (United States)

Kanehara, Masayuki; Watanabe, Yuka; Teranishi, Toshiharu

2009-01-01

We have successfully developed a method for silica coating on hydrophobic dodecanethiol-protected Au nanoparticles with coating thickness ranging from 10 to 40 nm. The formation of silica-coated Au nanoparticles could be accomplished via the preparation of hydrophilic Au nanoparticle micelles by cationic surfactant encapsulation in aqueous phase, followed by hydrolysis of tetraethylorthosilicate on the hydrophilic surface of gold nanoparticle micelles. Silica-coated Au nanoparticles exhibited quite high thermal stability, that is, no agglomeration of the Au cores could be observed after annealing at 600 degrees C for 30 min. Silica-coated Au nanoparticles could serve as a template to derive hollow nanoparticles. An addition of NaCN solution to silica-coated Au nanoparticles led the formation of hollow silica nanoparticles, which were redispersible in deionized water. The formation of the hollow silica nanoparticles results from the mesoporous structures of the silica shell and such a mesoporous structure is applicable to both catalyst support and drug delivery.
Chitosan-silica complex membranes from sulfonic acid functionalized silica nanoparticles for pervaporation dehydration of ethanol-water solutions.

Science.gov (United States)

Liu, Ying-Ling; Hsu, Chih-Yuan; Su, Yu-Huei; Lai, Juin-Yih

2005-01-01

Nanosized silica particles with sulfonic acid groups (ST-GPE-S) were utilized as a cross-linker for chitosan to form a chitosan-silica complex membranes, which were applied to pervaporation dehydration of ethanol-water solutions. ST-GPE-S was obtained from reacting nanoscale silica particles with glycidyl phenyl ether, and subsequent sulfonation onto the attached phenyl groups. The chemical structure of the functionalized silica was characterized with FTIR, (1)H NMR, and energy-dispersive X-ray. Homogeneous dispersion of the silica particles in chitosan was observed with electronic microscopies, and the membranes obtained were considered as nanocomposites. The silica nanoparticles in the membranes served as spacers for polymer chains to provide extra space for water permeation, so as to bring high permeation rates to the complex membranes. With addition of 5 parts per hundred of functionalized silica into chitosan, the resulting membrane exhibited a separation factor of 919 and permeation flux of 410 g/(m(2) h) in pervaporation dehydration of 90 wt % ethanol aqueous solution at 70 degrees C.
Performance of Differents Genotyps of Brazilian Orchid Cultivation in Alternatives Substrates

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Ricardo Tadeu de Faria

2001-12-01

Full Text Available Two native Brazilian orchid especies, Oncidium baueri and Maxillaria picta, were grown in different substrate mixtures. The plants were cultivated in ceramic pots in a greenhouse with 50% of shadind light and watered three times a week. The following substrates were used: 1 de-fibered xaxim; 2xaxim cubes; 3 vermiculite; 4 carbonized rice husk; 5 charcoal; 6 charcoal + carbonized rice husk; 7 crocks; 8 vermiculite and charcoal; 9 vermiculite + carbonized rice husks; 10 extruded polystyrene + charcoal; 11 pine bark + charcoal + extruded polystyrene; 12 vermiculite + carbonized rice husks + extruded polystyrene + charcoal; 13 pine bark. The substrate ratio was 1:1 in the mixture. NPK 10-10-10 leaf fertilizer was applied every thirty days and castor bean cake and bone powder organic fertilizer were applied every ninety days. A randomized complete block design was used with 10 replications. Growth and rooting were assessed after eight months. The best alternative substrate to O. baueri was vermiculie and the best alternatives substrates to M. picta were vermiculite and charcoal and vermiculite + carbonized rice husks.Diferentes misturas de substratos foram estudados para duas variedades de orquídeas nativas do Brasil: Oncidium baueri e Maxillaria pictea. As plantas foram cultivadas em vasos de cerâmica em casa de vegetação com 50% de luminosidade e regadas 3 vezes por semana. Os substratos utilizados foram os seguintes: 1xaxim desfibrado; 2xaxim e cubos; 3vermiculita; 4casca de arroz carbonizada; 5carvão; 6carvão + casca de arroz carbonizada; 7cacos de cerâmica; 8vermiculita + carvão; 9vermiculita + casca da arroz carbonizada; 10isopor + carvão; 11casca de pinus + carvão + isopor; 12 vermiculita + casca da arroz carbonizada + isopor + carvão; 13casca de pinus. A proporção dos substratos foi de 1:1na mistura. A cada trinta dias foi realizado uma adubação foliar com NPK: 10-10-10 e a cada 90 dias uma adubação orgânica com torta de
Rice Cluster I, an Important Group of Archaea Producing Methane in Rice Fields

Science.gov (United States)

Conrad, R.

2006-12-01

Rice fields are an important source for the greenhouse gas methane. Methane is a major degradation product of organic matter in the anoxic soil, is partially oxidized in the rhizosphere and is emitted into the atmosphere through the aerenchyma system of the plants. Anaerobic degradation of organic matter by fermenting bacteria eventually results in the production of acetate and hydrogen, the two major substrates for microbial methanogenesis. The community of methanogenic archaea consists of several major orders or families including hydrogen-utilizing Rice Cluster-I (RC-I). Environmental conditions affect the methanogenic degradation process and the community structure of the methanogenic archaea in soil and rhizosphere. For example, populations of acetoclastic Methanosaetaceae and Methanosarcinaceae are enhanced by low and high acetate concentrations, respectively. Stable isotope probing of 16S rRNA showed that RC-I methanogens are mainly active on rice roots and at low H2 concentrations. Growth and population size is largely consistent with energetic conditions. RC-I methanogens on roots seem to be responsible for methane production from plant photosynthates that account for a major part of the emitted methane. Populations of RC-I methanogens in rice field soil are also enhanced at elevated temperatures (40-50°C). Moderately thermophilic members of RC-I methanogens or other methanogenic families were found to be ubiquitously present in soils from rice fields and river marshes. The genome of a RC-I methanogen was completely sequenced out of an enrichment culture using a metagenome approach. Genes found are consistent with life in the rhizosphere and in temporarily drained, oxic soil. We found that the methanogenic community structure on the rice roots is mainly determined by the respective community structure of the soil, but is in addition affected by the rice cultivar. Rice microcosms in which soil and rice roots are mainly colonized by RC-I methanogens produce
Electricity production potential and social benefits from rice husk, a case study in Pakistan

Directory of Open Access Journals (Sweden)

Obaidullah Mohiuddin

2016-12-01

Full Text Available Pakistan has been experiencing energy crisis owing to its sole dependence on fossil fuels. Reduction in local fossil fuel reserves has led to an increase in their prices, thereby increasing the cost of electricity. Since the tariff remains the same, Pakistan is over-burdened with circular debts and observes a daily power shortfall of about 12–14 h. Being an Agra-economic country, many major and minor crops are produced and exported in large quantities. This results in a bulk of the agricultural waste which are not utilized. The waste can be utilized to meet the country’s energy demand while mitigating climate change and its impact. The study examines the electricity production potential and social benefits of rice husk in Pakistan. It is estimated in this study that if 70% of rice husk residues are utilized, there will be annual electricity production of 1,328 GWh and the cost of per unit electricity by rice husk is found at 47.36 cents/kWh as compared to 55.22 cents/kWh of electricity generated by coal. Importantly, the study will increase the awareness of the benefits of utilizing agricultural waste for useful products such as silica, with several social and environmental benefits such as a reduction of 36,042 tCO2e/yr of methane, reducing carbon dioxide emissions, improving the air quality, and providing 4.5 k new jobs. The paper concludes with the policy recommendations based on this study.
Cellular membrane trafficking of mesoporous silica nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Fang, I-Ju [Iowa State Univ., Ames, IA (United States)

2012-01-01

This dissertation mainly focuses on the investigation of the cellular membrane trafficking of mesoporous silica nanoparticles. We are interested in the study of endocytosis and exocytosis behaviors of mesoporous silica nanoparticles with desired surface functionality. The relationship between mesoporous silica nanoparticles and membrane trafficking of cells, either cancerous cells or normal cells was examined. Since mesoporous silica nanoparticles were applied in many drug delivery cases, the endocytotic efficiency of mesoporous silica nanoparticles needs to be investigated in more details in order to design the cellular drug delivery system in the controlled way. It is well known that cells can engulf some molecules outside of the cells through a receptor-ligand associated endocytosis. We are interested to determine if those biomolecules binding to cell surface receptors can be utilized on mesoporous silica nanoparticle materials to improve the uptake efficiency or govern the mechanism of endocytosis of mesoporous silica nanoparticles. Arginine-glycine-aspartate (RGD) is a small peptide recognized by cell integrin receptors and it was reported that avidin internalization was highly promoted by tumor lectin. Both RGD and avidin were linked to the surface of mesoporous silica nanoparticle materials to investigate the effect of receptor-associated biomolecule on cellular endocytosis efficiency. The effect of ligand types, ligand conformation and ligand density were discussed in Chapter 2 and 3. Furthermore, the exocytosis of mesoporous silica nanoparticles is very attractive for biological applications. The cellular protein sequestration study of mesoporous silica nanoparticles was examined for further information of the intracellular pathway of endocytosed mesoporous silica nanoparticle materials. The surface functionality of mesoporous silica nanoparticle materials demonstrated selectivity among the materials and cancer and normal cell lines. We aimed to determine
Effect of waxy rice flour and cassava starch on freeze-thaw stability of rice starch gels.

Science.gov (United States)

Charoenrein, Sanguansri; Preechathammawong, Nutsuda

2012-10-01

Repeatedly frozen and thawed rice starch gel affects quality. This study investigated how incorporating waxy rice flour (WF) and cassava starch (CS) in rice starch gel affects factors used to measure quality. When rice starch gels containing 0-2% WF and CS were subjected to 5 freeze-thaw cycles, both WF and CS reduced the syneresis in first few cycles. However CS was more effective in reducing syneresis than WF. The different composite arrangement of rice starch with WF or CS caused different mechanisms associated with the rice starch gel retardation of retrogradation, reduced the spongy structure and lowered syneresis. Both swollen granules of rice starch and CS caused an increase in the hardness of the unfrozen and freeze-thawed starch gel while highly swollen WF granules caused softer gels. These results suggested that WF and CS were effective in preserving quality in frozen rice starch based products. Copyright © 2012 Elsevier Ltd. All rights reserved.
Electricity generation from rice husk in Indian rice mills: potential and financial viability

International Nuclear Information System (INIS)

Kapur, T.; Kandpal, T.C.; Garg, H.P.

1998-01-01

Rice husk generated as a by-product of rice processing is an important energy resource. The availability of this resource in India has been assessed and the technologies for exploitation of its energy potential in the rice processing industry discussed. Nomographs have been developed for estimation of the husk required to meet the energy of parboiling, drying and milling operations. The unit cost of electricity using rice husk gasifier-based power generation systems has been calculated and its financial feasibility assessed in comparison with utility-supplied and diesel-generated electricity. With the cost and efficiency data assumed here, the unit cost of electricity produced by rice husk gasifier-dual fuel engine-generator system varies between Rs 2/kWh and Rs 7/kWh. (35 Rs approximates to SUS 1.). (author)
Electricity generation from rice husk in Indian rice mills: potential and financial viability

Energy Technology Data Exchange (ETDEWEB)

Kapur, T.; Kandpal, T.C.; Garg, H.P. [Indian Inst. of Technology, Centre for Energy Studies, New Delhi (India)

1998-12-31

Rice husk generated as a by-product of rice processing is an important energy resource. The availability of this resource in India has been assessed and the technologies for exploitation of its energy potential in the rice processing industry discussed. Nomographs have been developed for estimation of the husk required to meet the energy of parboiling, drying and milling operations. The unit cost of electricity using rice husk gasifier-based power generation systems has been calculated and its financial feasibility assessed in comparison with utility-supplied and diesel-generated electricity. With the cost and efficiency data assumed here, the unit cost of electricity produced by rice husk gasifier-dual fuel engine-generator system varies between Rs 2/kWh and Rs 7/kWh. (35 Rs approximates to SUS 1.). (author)
Evidence for Non-Transmission of Rice Yellow Mottle Virus (RYMV through Rice Seed

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Sy, AA.

2004-01-01

Full Text Available An indexing of the organs (radicle and plumule and components (husk, endosperm and embryo of rice seeds using Enzyme Linked Immunosorbent Assay (ELISA was carried out to detect Rice yellow mottle virus (RYMV and establish the exact location of the virus in the rice seed. RYMV was detected only in the husk (seed coat but not in the endosperm, plumule, radicle, nor embryo. None of the seedlings raised from the seeds expressed RYMV symptoms. No virus particle was detected by the ELISA test in the leaves of the screenhouse-reared plants obtained from seeds of infected plants. The results indicate that RYMV is apparently not transmitted through rice seed probably because the virus is seed-borne in the husk (seed coat of mature rice seeds.
Synthesis of Various Silica Nanoparticles for Foam Stability

International Nuclear Information System (INIS)

Yoon, Suk Bon; Yoon, Inho; Jung, Chonghun; Kim, Chorong; Choi, Wangkyu; Moon, Jeikwon

2013-01-01

The synthesis of the non-porous silica nanoparticles with uniform sizes has been reported through the Sto ber method, the synthesis of meso porous silica nanoparticles with a specific morphology such as core-shell, rod-like, and hexagonal shapes is not so common. As a synthetic strategy for controlling the particle size, shape, and porosity, the synthesis of core-shell silicas with meso porous shells formed on silica particle cores through the self-assembly of silica precursor and organic templates or spherical meso porous silicas using modified Sto ber method was also reported. Recently, in an effort to reduce the amount of radioactive waste and enhance the decontamination efficiency during the decontamination process of nuclear facilities contaminated with radionuclides, a few research for the preparation of the decontamination foam containing solid nanoparticles has been reported. In this work, the silica nanoparticles with various sizes, shapes, and structures were synthesized based on the previous literatures. The resulting silica nanoparticles were used to investigate the effect of the nanoparticles on the foam stability. In a study on the foam stability using various silica nanoparticles, the results showed that the foam volume and liquid volume in foam was enhanced when using a smaller size and lower density of the silica nanoparticles. Silica nanoparticles with various sizes, shapes, and structures such as a non-porous, meso porous core-shell, and meso porous silica were synthesized to investigate the effect of the foam stability. The sizes and structural properties of the silica nanoparticles were easily controlled by varying the amount of silica precursor, surfactant, and ammonia solution as a basic catalyst. The foam prepared using various silica nanoparticles showed that foam the volume and liquid volume in the foam were enhanced when using a smaller size and lower density of the silica nanoparticles
Silica removal in industrial effluents with high silica content and low hardness.

Science.gov (United States)

Latour, Isabel; Miranda, Ruben; Blanco, Angeles

2014-01-01

High silica content of de-inked paper mill effluents is limiting their regeneration and reuse after membrane treatments such as reverse osmosis (RO). Silica removal during softening processes is a common treatment; however, the effluent from the paper mill studied has a low hardness content, which makes the addition of magnesium compounds necessary to increase silica removal. Two soluble magnesium compounds (MgCl₂∙6H₂O and MgSO₄∙7H₂O) were tested at five dosages (250-1,500 mg/L) and different initial pH values. High removal rates (80-90%) were obtained with both products at the highest pH tested (11.5). With these removal efficiencies, it is possible to work at high RO recoveries (75-85%) without silica scaling. Although pH regulation significantly increased the conductivity of the waters (at pH 11.5 from 2.1 to 3.7-4.0 mS/cm), this could be partially solved by using Ca(OH)₂ instead of NaOH as pH regulator (final conductivity around 3.0 mS/cm). Maximum chemical oxygen demand (COD) removal obtained with caustic soda was lower than with lime (15 vs. 30%). Additionally, the combined use of a polyaluminum coagulant during the softening process was studied; the coagulant, however, did not significantly improve silica removal, obtaining a maximum increase of only 10%.
Comparison of postmenopausal endogenous sex hormones among Japanese, Japanese Brazilians, and non-Japanese Brazilians

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Maciel Maria

2011-02-01

Full Text Available Abstract Background Differences in sex hormone levels among populations might contribute to the variation in breast cancer incidence across countries. Previous studies have shown higher breast cancer incidence and mortality among Japanese Brazilians than among Japanese. To clarify the difference in hormone levels among populations, we compared postmenopausal endogenous sex hormone levels among Japanese living in Japan, Japanese Brazilians living in the state of São Paulo, and non-Japanese Brazilians living in the state of São Paulo. Methods A cross-sectional study was conducted using a control group of case-control studies in Nagano, Japan, and São Paulo, Brazil. Participants were postmenopausal women older than 55 years of age who provided blood samples. We measured estradiol, estrone, androstenedione, dehydroepiandrosterone sulfate (DHEAS, testosterone and free testosterone by radioimmunoassay; bioavailable estradiol by the ammonium sulfate precipitation method; and sex hormone-binding globulin (SHBG by immunoradiometric assay. A total of 363 women were included for the present analyses, comprising 185 Japanese, 44 Japanese Brazilians and 134 non-Japanese Brazilians. Results Japanese Brazilians had significantly higher levels of estradiol, bioavailable estradiol, estrone, testosterone and free testosterone levels, and lower SHBG levels, than Japanese. Japanese Brazilians also had significantly higher levels of bioavailable estradiol, estrone and DHEAS and lower levels of SHBG and androstenedione than non-Japanese Brazilians. Levels of estradiol, testosterone and free testosterone, however, did not differ between Japanese Brazilians and non-Japanese Brazilians. These differences were observed even after adjustment for known breast cancer risk factors. We also found an increase in estrogen and androgen levels with increasing body mass index, but no association for most of the other known risk factors. Conclusions We found higher levels of

Impact of bio-processing on rice

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ANCA NICOLAU

2011-07-01

Full Text Available The usual way of preparing rice is boiling, thermal process that gives it a lower digestibility as compared to instantiation, extrusion or expandation. Having in view this fact, the possibility to biotechnologically improve the boiled rice digestibility was investigated in a laboratory study. In this respect, boiled rice wassolid state fermented using a strain of Saccharomycopsis fibuligera, an amylase producing yeast originating from ragi. Fermented rice was then analyzed from the point of view of its content in easily assimilable sugars, protein, amino-acids, phosphorus and vitamins from B group. Biochemical analyses revealed that the fermented rice has a ten times higher content of reducing sugars than boiled rice, due to starch hydrolysis, while chromatographic studies proved that the fermented rice contains glucose, maltose, maltotriose and maltotetrose that are easily assimilable carbohydrates.Fermented rice has a protein content that is two times higher than that of boiled rice because it contains the yeast biomass, and is enriched in vitamins from B group (B1, B2, and B6 that are synthesized by the yeast. Inorganic phosphorus present in rice doubles its concentration in fermented rice, which means thatphosphorus bioavailability is increased.The sensorial profile of boiled rice is also improved by fermentation.This study proves the possibility to have a processing method which is relatively cheap, practical and of which the resulting product has good nutritive qualities and does not pose safety problems due to pure culture utilization as starter.
Storage stability of flour-blasted brown rice

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Brown rice was blasted with rice flour rather than sand in a sand blaster to make microscopic nicks and cuts so that water can easily penetrate into the brown rice endosperm and cook the rice in a shorter time. The flour-blasted American Basmati brown rice, long grain brown rice, and parboiled long...
Mapping paddy rice planting area in rice-wetland coexistent areas through analysis of Landsat 8 OLI and MODIS images.

Science.gov (United States)

Zhou, Yuting; Xiao, Xiangming; Qin, Yuanwei; Dong, Jinwei; Zhang, Geli; Kou, Weili; Jin, Cui; Wang, Jie; Li, Xiangping

2016-04-01

Accurate and up-to-date information on the spatial distribution of paddy rice fields is necessary for the studies of trace gas emissions, water source management, and food security. The phenology-based paddy rice mapping algorithm, which identifies the unique flooding stage of paddy rice, has been widely used. However, identification and mapping of paddy rice in rice-wetland coexistent areas is still a challenging task. In this study, we found that the flooding/transplanting periods of paddy rice and natural wetlands were different. The natural wetlands flood earlier and have a shorter duration than paddy rice in the Panjin Plain, a temperate region in China. We used this asynchronous flooding stage to extract the paddy rice planting area from the rice-wetland coexistent area. MODIS Land Surface Temperature (LST) data was used to derive the temperature-defined plant growing season. Landsat 8 OLI imagery was used to detect the flooding signal and then paddy rice was extracted using the difference in flooding stages between paddy rice and natural wetlands. The resultant paddy rice map was evaluated with in-situ ground-truth data and Google Earth images. The estimated overall accuracy and Kappa coefficient were 95% and 0.90, respectively. The spatial pattern of OLI-derived paddy rice map agrees well with the paddy rice layer from the National Land Cover Dataset from 2010 (NLCD-2010). The differences between Rice Landsat and Rice NLCD are in the range of ±20% for most 1-km grid cell. The results of this study demonstrate the potential of the phenology-based paddy rice mapping algorithm, via integrating MODIS and Landsat 8 OLI images, to map paddy rice fields in complex landscapes of paddy rice and natural wetland in the temperate region.
International tourist preference of Lodok Rice Field natural elements, the cultural rice field from Manggarai - Indonesia

Science.gov (United States)

March Syahadat, Ray; Trie Putra, Priambudi; Nuraini; Nailufar, Balqis; Fatmala Makhmud, Desy

2017-10-01

Lodok Rice Field or usually known as spiderweb rice field is a system of land division. It cultural rice field only found on Manggarai, Province of East Nusa Tenggara, Indonesia. The landscape of Lodok Rice Field was aesthetic and it has big potential for tourism development. The aim of this study was to know the perception of natural elements of Lodok Rice Field landscape that could influence international tourist to visited Lodok Rice Field. If we know the elements that could influenced the international tourist, we could used the landscape image for tourism media promotion. The methods of this study used scenic beauty estimation (SBE) by 85 respondents from 34 countries and Kruskal Wallis H test. The countries grouped by five continents (Asia, America, Europe, Africa, and Oceania). The result showed that the Asian respondents liked the elements of sky, mountain, and the rice field. Then, the other respondent from another continent liked the elements of sunshine, mountain, and the rice field. Although the Asian had different perception about landscape elements of rice field’s good view, it’s not differ significantly by Kruskal Wallis H test.
Defensive Responses of Rice Genotypes for Resistance Against Rice Leaffolder Cnaphalocrocis medinalis

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M. PUNITHAVALLI

2013-09-01

Full Text Available The experiment was carried out to assess the reaction of different categories of rice genotypes viz., resistant, susceptible, hybrid, scented, popular and wild in response to the infestation by rice leaffolder (RLF, Cnaphalocrocis medinalis (Guenee and to explore the possible use of these genotypes in developing RLF-resistant rice varieties. The changes of various biochemical constituents such as leaf soluble protein, phenol, ortho-dihydroxy phenol, tannin and enzymes viz., peroxidase, phenyl alanine ammonia lyase (PAL were assessed spectrophotometrically in all the rice genotypes before and after RLF infestation. The protein profile was analyzed using sodium dodecyl sulphate-poly acrylamide gel electrophoresis (SDS-PAGE method. A significant constituent of biochemical content such as tannin, phenol and ortho-dihydroxy phenol has been increased along with enzyme activities of peroxidase and PAL in the infested resistant (Ptb 33, TKM6 and LFR831311 and wild rice genotypes (Oryza minuta and O. rhizomatis. A decrease in leaf protein content was evident invariably in all the infested rice genotypes. It is also evident that the contents of biochemicals such as phenol, ortho-dihydroxy phenol and tannin were negatively correlated with leaffolder damage. However, leaf protein content was positively correlated with the damage by rice leaffolder. SDS-PAGE analysis for total protein profiling of healthy and C. medinalis-infested genotypes revealed the enhanced expression of a high molecular weight (> 97 kDa protein in all the genotypes. Besides, there was also an increased induction of a 38 kDa protein in C. medinalis infested resistant genotypes, which was absent in uninfested plants. The present investigation proved that the elevated levels of biochemicals and enzymes may play a vital role in rice plants resistance to RLF.
Lead in rice: analysis of baseline lead levels in market and field collected rice grains.

Science.gov (United States)

Norton, Gareth J; Williams, Paul N; Adomako, Eureka E; Price, Adam H; Zhu, Yongguan; Zhao, Fang-Jie; McGrath, Steve; Deacon, Claire M; Villada, Antia; Sommella, Alessia; Lu, Ying; Ming, Lei; De Silva, P Mangala C S; Brammer, Hugh; Dasgupta, Tapash; Islam, M Rafiqul; Meharg, Andrew A

2014-07-01

In a large scale survey of rice grains from markets (13 countries) and fields (6 countries), a total of 1578 rice grain samples were analysed for lead. From the market collected samples, only 0.6% of the samples exceeded the Chinese and EU limit of 0.2 μg g(-1) lead in rice (when excluding samples collected from known contaminated/mine impacted regions). When evaluating the rice grain samples against the Food and Drug Administration's (FDA) provisional total tolerable intake (PTTI) values for children and pregnant women, it was found that only people consuming large quantities of rice were at risk of exceeding the PTTI from rice alone. Furthermore, 6 field experiments were conducted to evaluate the proportion of the variation in lead concentration in rice grains due to genetics. A total of 4 of the 6 field experiments had significant differences between genotypes, but when the genotypes common across all six field sites were assessed, only 4% of the variation was explained by genotype, with 9.5% and 11% of the variation explained by the environment and genotype by environment interaction respectively. Further work is needed to identify the sources of lead contamination in rice, with detailed information obtained on the locations and environments where the rice is sampled, so that specific risk assessments can be performed. Copyright © 2014 Elsevier B.V. All rights reserved.
Genomic dissection of small RNAs in wild rice (Oryza rufipogon): lessons for rice domestication.

Science.gov (United States)

Wang, Yu; Bai, Xuefei; Yan, Chenghai; Gui, Yiejie; Wei, Xinghua; Zhu, Qian-Hao; Guo, Longbiao; Fan, Longjiang

2012-11-01

The lack of a MIRNA set and genome sequence of wild rice (Oryza rufipogon) has prevented us from determining the role of MIRNA genes in rice domestication. In this study, a genome, three small RNA populations and a degradome of O. rufipogon were sequenced by Illumina platform and the expression levels of microRNAs (miRNAs) were investigated by miRNA chips. A de novo O. rufipogon genome was assembled using c. 55× coverage of raw sequencing data and a total of 387 MIRNAs were identified in the O. rufipogon genome based on c. 5.2 million unique small RNA reads from three different tissues of O. rufipogon. Of these, O. rufipogon MIRNAs, 259 were not found in the cultivated rice, suggesting a loss of these MIRNAs in the cultivated rice. We also found that 48 MIRNAs were novel in the cultivated rice, suggesting that they were potential targets of domestication selection. Some miRNAs showed significant expression differences between wild and cultivated rice, suggesting that expression of miRNA could also be a target of domestication, as demonstrated for the miR164 family. Our results illustrated that MIRNA genes, like protein-coding genes, might have been significantly shaped during rice domestication and could be one of the driving forces that contributed to rice domestication. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.
Do rice water weevils and rice stem borers compete when sharing a host plant?

Science.gov (United States)

Shi, Sheng-Wei; He, Yan; Ji, Xiang-Hua; Jiang, Ming-Xing; Cheng, Jia-An

2008-07-01

The rice water weevil (RWW) Lissorhoptrus oryzophilus Kuschel (Coleoptera: Curculionidae) is an invasive insect pest of rice Oryza sativa L. in China. Little is known about the interactions of this weevil with indigenous herbivores. In the present study, adult feeding and population density of the weevil, injury level of striped stem borer Chilo suppressalis (Walker) (Lepidoptera: Pyralidae) and pink stem borer Sesamia inferens (Walker) (Lepidoptera: Noctuidae) to rice, as well as growth status of their host plants were surveyed in a rice field located in Southeastern Zhejiang, China, in 2004 with the objective to discover interspecific interactions on the rice. At tillering stage, both adult feeding of the weevil and injury of the stem borers tended to occur on larger tillers (bearing 5 leaves) compared with small tillers (bearing 2~4 leaves), but the insects showed no evident competition with each other. At booting stage, the stem borers caused more withering/dead hearts and the weevil reached a higher density on the plants which had more productive tillers and larger root system; the number of weevils per tiller correlated negatively with the percentage of withering/dead hearts of plants in a hill. These observations indicate that interspecific interactions exist between the rice water weevil and the rice stem borers with negative relations occurring at booting or earlier developmental stages of rice.
Do rice water weevils and rice stem borers compete when sharing a host plant?*

Science.gov (United States)

Shi, Sheng-wei; He, Yan; Ji, Xiang-hua; Jiang, Ming-xing; Cheng, Jia-an

2008-01-01

The rice water weevil (RWW) Lissorhoptrus oryzophilus Kuschel (Coleoptera: Curculionidae) is an invasive insect pest of rice Oryza sativa L. in China. Little is known about the interactions of this weevil with indigenous herbivores. In the present study, adult feeding and population density of the weevil, injury level of striped stem borer Chilo suppressalis (Walker) (Lepidoptera: Pyralidae) and pink stem borer Sesamia inferens (Walker) (Lepidoptera: Noctuidae) to rice, as well as growth status of their host plants were surveyed in a rice field located in Southeastern Zhejiang, China, in 2004 with the objective to discover interspecific interactions on the rice. At tillering stage, both adult feeding of the weevil and injury of the stem borers tended to occur on larger tillers (bearing 5 leaves) compared with small tillers (bearing 2~4 leaves), but the insects showed no evident competition with each other. At booting stage, the stem borers caused more withering/dead hearts and the weevil reached a higher density on the plants which had more productive tillers and larger root system; the number of weevils per tiller correlated negatively with the percentage of withering/dead hearts of plants in a hill. These observations indicate that interspecific interactions exist between the rice water weevil and the rice stem borers with negative relations occurring at booting or earlier developmental stages of rice. PMID:18600788
Synthesis of Na-A and/or Na-X zeolite/porous carbon composites from carbonized rice husk

International Nuclear Information System (INIS)

Katsuki, Hiroaki; Komarneni, Sridhar

2009-01-01

Na-A and/or Na-X zeolite/porous carbon composites were prepared under hydrothermal conditions by NaOH dissolution of silica first from carbonized rice husk followed by addition of NaAlO 2 and in situ crystallization of zeolites i.e., using a two-step process. When a one-step process was used, both Na-A and Na-X zeolites crystallized on the surface of carbon. Na-A or Na-X zeolite crystals were prepared on the porous carbonized rice husk at 90 deg. C for 2-6 h by changing the SiO 2 /Al 2 O 3 , H 2 O/Na 2 O and Na 2 O/SiO 2 molar ratios of precursors in the two-step process. The surface area and NH 4 + -cation exchange capacity (CEC) of Na-A zeolite/porous carbon were found to be 171 m 2 /g and 506 meq/100 g, respectively, while those of Na-X zeolite/porous carbon composites were 676 m 2 /g and 317 meq/100 g, respectively. Na-A and Na-X zeolites are well-known microporous and hydrophilic materials while carbonized rice husk was found to be mesoporous (pores of ∼3.9 nm) and hydrophobic. These hybrid microporous-mesoporous and hydrophilic-hydrophobic composites are expected to be useful for decontamination of metal cations as well as organic contaminants simultaneously. - Graphical Abstract: Novel Na-X zeolite/porous carbon composite.
Field trial of GABA-fortified rice plants and oral administration of milled rice in spontaneously hypertensive rats.

Science.gov (United States)

Kowaka, Emi; Shimajiri, Yasuka; Kawakami, Kouhei; Tongu, Miki; Akama, Kazuhito

2015-06-01

Hypertension is one of the most critical risk factors accompanying cardiovascular diseases. γ-Aminobutyric acid (GABA) is a non-protein amino acid that functions as a major neurotransmitter in mammals and also as a blood-pressure lowering agent. We previously produced GABA-fortified rice lines of a popular Japonica rice cultivar 'Koshihikari' by genetic manipulation of GABA shunt-related genes. In the study reported here, we grew these same novel rice lines in a field trial and administered the milled rice orally to rats. The yield parameters of the transgenic rice plants were almost unchanged compared to those of untransformed cv. 'Koshihikari' plants, while the rice grains of the transgenic plants contained a high GABA content (3.5 g GABA/kg brown rice; 0.75-0.85 GABA g/kg milled rice) in a greenhouse trial. Oral administration of a diet containing 2.5% GABA-fortified rice, with a daily intake for 8 weeks, had an approximately 20 mmHg anti-hypertensive effect in spontaneous hypertensive rats but not in normotensive Wistar-Kyoto rats. These results suggest that GABA-fortified rice may be applicable as a staple food to control or prevent hypertension.
Effect of acetic acid on rice seeds coated with rice husk ash

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Lizandro Ciciliano Tavares

2013-06-01

Full Text Available Flooded rice cultivation promotes anaerobic conditions, favoring the formation of short chain organic acids such as acetic acid, which may be toxic to the crop. The objective of this study was to evaluate the effect of acetic acid on rice seeds coated with rice husk ash. The experiment was arranged in a 2 x 5 x 5 factorial randomized design, with two cultivars (IRGA 424 and BRS Querência, five doses of coating material (0, 2, 3,4 e 5 g kg-1 seed and five concentrations of acetic acid (0, 3, 6, 9 and 12 mM, with 4 replications, totaling 50 treatments. The variables first count of germination, germination, shoot and root length, dry weight of shoots and roots were recorded. The results showed that coating rice seeds with rice husk ash up to 5 g kg-1 seed does not influence the performance of rice seeds of cultivars IRGA 424 and BRS Querência when exposed to concentrations of 12 mM acetic acid. The presence of acetic acid in the substrates used for seed germination reduced the vigor and viability of seeds of cultivars IRGA 424 and BRS Querência, as well as seedling development, affecting mainly the roots of BRS Querência.
The impact of herbicide-resistant rice technology on phenotypic diversity and population structure of United States weedy rice.

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Burgos, Nilda Roma; Singh, Vijay; Tseng, Te Ming; Black, Howard; Young, Nelson D; Huang, Zhongyun; Hyma, Katie E; Gealy, David R; Caicedo, Ana L

2014-11-01

The use of herbicide-resistant (HR) Clearfield rice (Oryza sativa) to control weedy rice has increased in the past 12 years to constitute about 60% of rice acreage in Arkansas, where most U.S. rice is grown. To assess the impact of HR cultivated rice on the herbicide resistance and population structure of weedy rice, weedy samples were collected from commercial fields with a history of Clearfield rice. Panicles from each weedy type were harvested and tested for resistance to imazethapyr. The majority of plants sampled had at least 20% resistant offspring. These resistant weeds were 97 to 199 cm tall and initiated flowering from 78 to 128 d, generally later than recorded for accessions collected prior to the widespread use of Clearfield rice (i.e. historical accessions). Whereas the majority (70%) of historical accessions had straw-colored hulls, only 30% of contemporary HR weedy rice had straw-colored hulls. Analysis of genotyping-by-sequencing data showed that HR weeds were not genetically structured according to hull color, whereas historical weedy rice was separated into straw-hull and black-hull populations. A significant portion of the local rice crop genome was introgressed into HR weedy rice, which was rare in historical weedy accessions. Admixture analyses showed that HR weeds tend to possess crop haplotypes in the portion of chromosome 2 containing the ACETOLACTATE SYNTHASE gene, which confers herbicide resistance to Clearfield rice. Thus, U.S. HR weedy rice is a distinct population relative to historical weedy rice and shows modifications in morphology and phenology that are relevant to weed management. © 2014 American Society of Plant Biologists. All Rights Reserved.
Residues and accumulation of molinate in rice crops and aquatic weeds in the MUDA rice agroecosystem

International Nuclear Information System (INIS)

Nashriyah Mat; Sabri Junoh; Nuriati Nurdin; Ramli Ishak

2002-01-01

Plant and soil residue levels and its accumulation in rice crops and rice aquatic weed plants were studied. Molinate residue levels in rice, weeds and soil were not significantly different between the recycled and the non-recycled area, even though they were higher in the non-recycled area. In the rice plant, the residue level at 10 DAT (days after treatment) was significantly higher than 30 DAT in the recycled area. In rice aquatic weed plants, the residue level was significantly higher at 10 DAT as compared to 30 DAT in the non-recycled area. Molinate residue levels in soil at 10 DAT and 30 DAT were similar. Molinate accumulated (ratio of molinate concentration in plant over soil) more in the rice crop as compared to rice aquatic weeds at 10 DAT, in both the recycled and the non-recycled areas. (Author)
Arsenic accumulation in rice: Consequences of rice genotypes and management practices to reduce human health risk.

Science.gov (United States)

Islam, Shofiqul; Rahman, Mohammad Mahmudur; Islam, M R; Naidu, Ravi

2016-11-01

Rice is an essential staple food and feeds over half of the world's population. Consumption of rice has increased from limited intake in Western countries some 50years ago to major dietary intake now. Rice consumption represents a major route for inorganic arsenic (As) exposure in many countries, especially for people with a large proportion of rice in their daily diet as much as 60%. Rice plants are more efficient in assimilating As into its grains than other cereal crops and the accumulation may also adversely affect the quality of rice and their nutrition. Rice is generally grown as a lowland crop in flooded soils under reducing conditions. Under these conditions the bioavailability of As is greatly enhanced leading to excessive As bioaccumulation compared to that under oxidizing upland conditions. Inorganic As species are carcinogenic to humans and even at low levels in the diet pose a considerable risk to humans. There is a substantial genetic variation among the rice genotypes in grain-As accumulation as well as speciation. Identifying the extent of genetic variation in grain-As concentration and speciation of As compounds are crucial to determining the rice varieties which accumulate low inorganic As. Varietal selection, irrigation water management, use of fertilizer and soil amendments, cooking practices etc. play a vital role in reducing As exposure from rice grains. In the meantime assessing the bioavailability of As from rice is crucial to understanding human health exposure and reducing the risk. Copyright © 2016 Elsevier Ltd. All rights reserved.
[Effects of rice cleaning and cooking process on the residues of flutolanil, fenobucarb, silafluofen and buprofezin in rice].

Science.gov (United States)

Satoh, Motoaki; Sakaguchi, Masayuki; Kobata, Masakazu; Sakaguchi, Yoko; Tanizawa, Haruna; Miura, Yuri; Sasano, Ryoichi; Nakanishi, Yutaka

2003-02-01

We studied the effect of cleaning and cooking on the residues of flutolanil, fenobucarb, silafluofen and buprofezin in rice. The rice had been sprayed in a paddy field in Wakayama city, with 3 kinds of pesticide application protocols: spraying once at the usual concentration of pesticides, repeated spraying (3 times) with the usual concentration of pesticides and spraying once with 3 times the usual concentration of pesticides. The residue levels of pesticide decreased during the rice cleaning process. Silafluofen, which has a higher log Pow value, remained in the hull of the rice. Fenobucarb, which has a lower log Pow value, penetrated inside the rice. The residue concentration of pesticide in polished rice was higher than that in pre-washed rice processed ready for cooking. During the cooking procedure, the reduction of pesticides in polished rice was higher than that in brown rice.
The Pozzolanic reaction of silica fume

DEFF Research Database (Denmark)

Jensen, Ole Mejlhede

2012-01-01

Silica fume is a very important supplementary cementitious binder in High-Performance and Ultra High-Performance Concretes. Through its pozzolanic reaction the silica fume densifies the concrete micro-structure, in particular it strengthens the paste-aggregate interfacial transition zone. In the ......Silica fume is a very important supplementary cementitious binder in High-Performance and Ultra High-Performance Concretes. Through its pozzolanic reaction the silica fume densifies the concrete micro-structure, in particular it strengthens the paste-aggregate interfacial transition zone....... In the present paper different aspects of the pozzolanic reaction of silica fume are investigated. These include chemical shrinkage, isothermal heat development and strength development. Key data for these are given and compared with theoretical calculations, and based on presented measurements the energy...
Molecular evolution of the rice blast resistance gene Pi-ta in invasive weedy rice in the USA.

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Seonghee Lee

Full Text Available The Pi-ta gene in rice has been effectively used to control rice blast disease caused by Magnaporthe oryzae worldwide. Despite a number of studies that reported the Pi-ta gene in domesticated rice and wild species, little is known about how the Pi-ta gene has evolved in US weedy rice, a major weed of rice. To investigate the genome organization of the Pi-ta gene in weedy rice and its relationship to gene flow between cultivated and weedy rice in the US, we analyzed nucleotide sequence variation at the Pi-ta gene and its surrounding 2 Mb region in 156 weedy, domesticated and wild rice relatives. We found that the region at and around the Pi-ta gene shows very low genetic diversity in US weedy rice. The patterns of molecular diversity in weeds are more similar to cultivated rice (indica and aus, which have never been cultivated in the US, rather than the wild rice species, Oryza rufipogon. In addition, the resistant Pi-ta allele (Pi-ta found in the majority of US weedy rice belongs to the weedy group strawhull awnless (SH, suggesting a single source of origin for Pi-ta. Weeds with Pi-ta were resistant to two M. oryzae races, IC17 and IB49, except for three accessions, suggesting that component(s required for the Pi-ta mediated resistance may be missing in these accessions. Signatures of flanking sequences of the Pi-ta gene and SSR markers on chromosome 12 suggest that the susceptible pi-ta allele (pi-ta, not Pi-ta, has been introgressed from cultivated to weedy rice by out-crossing.
Molecular Evolution of the Rice Blast Resistance Gene Pi-ta in Invasive Weedy Rice in the USA

Science.gov (United States)

Lee, Seonghee; Jia, Yulin; Jia, Melissa; Gealy, David R.; Olsen, Kenneth M.; Caicedo, Ana L.

2011-01-01

The Pi-ta gene in rice has been effectively used to control rice blast disease caused by Magnaporthe oryzae worldwide. Despite a number of studies that reported the Pi-ta gene in domesticated rice and wild species, little is known about how the Pi-ta gene has evolved in US weedy rice, a major weed of rice. To investigate the genome organization of the Pi-ta gene in weedy rice and its relationship to gene flow between cultivated and weedy rice in the US, we analyzed nucleotide sequence variation at the Pi-ta gene and its surrounding 2 Mb region in 156 weedy, domesticated and wild rice relatives. We found that the region at and around the Pi-ta gene shows very low genetic diversity in US weedy rice. The patterns of molecular diversity in weeds are more similar to cultivated rice (indica and aus), which have never been cultivated in the US, rather than the wild rice species, Oryza rufipogon. In addition, the resistant Pi-ta allele (Pi-ta) found in the majority of US weedy rice belongs to the weedy group strawhull awnless (SH), suggesting a single source of origin for Pi-ta. Weeds with Pi-ta were resistant to two M. oryzae races, IC17 and IB49, except for three accessions, suggesting that component(s) required for the Pi-ta mediated resistance may be missing in these accessions. Signatures of flanking sequences of the Pi-ta gene and SSR markers on chromosome 12 suggest that the susceptible pi-ta allele (pi-ta), not Pi-ta, has been introgressed from cultivated to weedy rice by out-crossing. PMID:22043312
21 CFR 584.700 - Hydrophobic silicas.

Science.gov (United States)

2010-04-01

...) Product. Amorphous fumed hydrophobic silica or precipitated hydrophobic silica (CAS Reg. No. 68611-0944... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Hydrophobic silicas. 584.700 Section 584.700 Food... DRUGS, FEEDS, AND RELATED PRODUCTS FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE IN FEED AND...

Biomimetic silica encapsultation of living cells

Science.gov (United States)

Jaroch, David Benjamin

Living cells perform complex chemical processes on size and time scales that artificial systems cannot match. Cells respond dynamically to their environment, acting as biological sensors, factories, and drug delivery devices. To facilitate the use of living systems in engineered constructs, we have developed several new approaches to create stable protective microenvironments by forming bioinspired cell-membrane-specific silica-based encapsulants. These include vapor phase deposition of silica gels, use of endogenous membrane proteins and polysaccharides as a site for silica nucleation and polycondensation in a saturated environment, and protein templated ordered silica shell formation. We demonstrate silica layer formation at the surface of pluripotent stem-like cells, bacterial biofilms, and primary murine and human pancreatic islets. Materials are characterized by AFM, SEM and EDS. Viability assays confirm cell survival, and metabolite flux measurements demonstrate normal function and no major diffusion limitations. Real time PCR mRNA analysis indicates encapsulated islets express normal levels of genetic markers for β-cells and insulin production. The silica glass encapsulant produces a secondary bone like calcium phosphate mineral layer upon exposure to media. Such bioactive materials can improve device integration with surrounding tissue upon implantation. Given the favorable insulin response, bioactivity, and long-term viability observed in silica-coated islets, we are currently testing the encapsulant's ability to prevent immune system recognition of foreign transplants for the treatment of diabetes. Such hybrid silica-cellular constructs have a wide range of industrial, environmental, and medical applications.
luminium alloy - rice husk ash composites production and analysis

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Abdullahi Mohammed USMAN

2014-11-01

Full Text Available This study was carried out to produce and analyse the properties of Aluminium Alloy-Rice Husk Ash composites. Rice husk ash (RHA with high silica content of up to 97.095% was used for the study with the RHA varied from 0vol% – 30vol% at intervals of 5vol% in the aluminium alloy as reinforcement. The density and some mechanical properties of the composites including tensile strength, impact strength, hardness and fatigue strength were investigated. The results showed that the density of the composite decreases with the percentage increase of reinforcement from 2840.242 kgm-3 for the control sample to 2402.899 kgm-3 for 30vol% RHA. The Ultimate Tensile Strength (UTS varies from 164.374 MNm-2 at 0% RHA to 176.837 MNm-2 with maximum value at 10% RHA, impact strength values varies from 84.020kJm-2 at 0% RHA to 155.244 kJm-2 with maximum value at 10% RHA, hardness value varies from 70.467 RHV at 0% RHA to 109.367 RHV with maximum value at 25% RHA and fatigue strength varies from 0.224x106 cycles to 2.582x106 cycles with maximum cycle at 20% RHA. The results of analysis of variance showed that there are significant differences among the means of each property of the composites at different levels of replacement of the ash addition (P<0.05. It was concluded that the produced composites could be used to make engineering components such as automobile body parts, piston and block engine etc.
Genome-wide analysis of Dongxiang wild rice (Oryza rufipogon Griff.) to investigate lost/acquired genes during rice domestication.

Science.gov (United States)

Zhang, Fantao; Xu, Tao; Mao, Linyong; Yan, Shuangyong; Chen, Xiwen; Wu, Zhenfeng; Chen, Rui; Luo, Xiangdong; Xie, Jiankun; Gao, Shan

2016-04-26

It is widely accepted that cultivated rice (Oryza sativa L.) was domesticated from common wild rice (Oryza rufipogon Griff.). Compared to other studies which concentrate on rice origin, this study is to genetically elucidate the substantially phenotypic and physiological changes from wild rice to cultivated rice at the whole genome level. Instead of comparing two assembled genomes, this study directly compared the Dongxiang wild rice (DXWR) Illumina sequencing reads with the Nipponbare (O. sativa) complete genome without assembly of the DXWR genome. Based on the results from the comparative genomics analysis, structural variations (SVs) between DXWR and Nipponbare were determined to locate deleted genes which could have been acquired by Nipponbare during rice domestication. To overcome the limit of the SV detection, the DXWR transcriptome was also sequenced and compared with the Nipponbare transcriptome to discover the genes which could have been lost in DXWR during domestication. Both 1591 Nipponbare-acquired genes and 206 DXWR-lost transcripts were further analyzed using annotations from multiple sources. The NGS data are available in the NCBI SRA database with ID SRP070627. These results help better understanding the domestication from wild rice to cultivated rice at the whole genome level and provide a genomic data resource for rice genetic research or breeding. One finding confirmed transposable elements contribute greatly to the genome evolution from wild rice to cultivated rice. Another finding suggested the photophosphorylation and oxidative phosphorylation system in cultivated rice could have adapted to environmental changes simultaneously during domestication.
Effect of Red Yeast Rice and Coconut, Rice Bran or Sunflower Oil Combination in Rats on Hypercholesterolemic Diet.

Science.gov (United States)

Govindarajan, Sumitra; Vellingiri, Kishore

2016-04-01

Dietary supplements provide a novel population based health approach for treating hyperlipidemias. Red yeast rice is known to have lipid lowering effects. Combination of red yeast rice with various oils is taken by different population around the world. In this present work, we aimed to compare the effects of red yeast rice with different oil (coconut, rice bran and sunflower oil) supplementations on lipid levels and oxidative stress in rats fed on hypercholesterolemic diet. A Randomized controlled study was conducted on 28 male Sprague Dawley rats. It included 4 arms-Control arm (hypercholesterolemic diet), Test arm A (hypercholesterolemic diet +Red yeast rice + Rice bran oil), arm B (hypercholesterolemic diet +Red yeast rice + Coconut oil) and arm C (hypercholesterolemic diet +Red yeast rice + Sunflower oil). At the end of one month, serum cholesterol, triglycerides, MDA and paraoxonase was measured. The mean values of analytes between the different groups were compared using student 't-' test. The rats fed with red yeast rice and rice bran oil combination showed significantly lower levels of serum cholesterol, triglycerides and MDA when compared to the controls. The serum paraoxonase levels were significantly higher in this group when compared to the controls. The rats fed with red yeast rice and coconut oil combination showed significantly lower serum cholesterol and MDA levels when compared to the controls. The mean triglyceride and paraoxonase levels did not show any statistically significant difference from the controls. The rats on red yeast rice and sunflower oil combination did not show any statistically significant difference in the lipid levels and oxidative stress parameters. The food combination which had best outcome in preventing the development of hyperlipidemia and oxidative stress in rats fed with hypercholesterolemic diet was red yeast rice and rice bran oil. Combining red yeast rice with coconut oil and sunflower oil gave suboptimal benefits.
Rice-eating quality among consumers in different rice grain preference countries

NARCIS (Netherlands)

Suwannaporn, P.; Linnemann, A.R.

2008-01-01

More rice is eaten nowadays in traditionally nonrice-eating countries. This study investigated consumer eating quality preferences among consumers in target rice export countries to identify opportunities and strategic implications. A quantitative study with 1,128 consumers of target nationalities
[The main nutrients digestibility of genetically modified rice and parental rice in the terminal ileum of pigs].

Science.gov (United States)

Li, Min; Hu, Yi-chun; Piao, Jian-hua; Yang, Xiao-guang

2010-10-01

To compare the digestibility of main nutrients in genetically modified rice with double antisense starch-branching enzyme gene and parental rice. Seven Wuzhishan healthy adult barrows were surgically fitted with a T-cannula at the terminal ileum. After surgery, seven pigs were randomly divided into two groups, and fed genetically modified rice and parental rice by a crossover model. Ileal digesta were collected for analysis of main nutrient digestibility. The apparent digestibility levels of protein in genetically modified rice and parental rice were 69.50% ± 4.50%, 69.61% ± 8.40%, respectively (t = 0.01, P = 0.994); true digestibility levels of protein were 87.55% ± 4.95%, 87.64% ± 9.40%, respectively (t = 0.01, P = 0.994); fat digestibility levels were 72.86% ± 0.34%, 77.89% ± 13.09%, respectively (t = 0.95, P = 0.378); carbohydrate digestibility levels were 72.92% ± 7.43%, 92.35% ± 5.88%, respectively (t = 4.27, P = 0.005). The apparent and true digestibility of 17 amino acids had no significant difference in the two rice. Carbohydrate digestibility in genetically modified rice was significantly lower than that in non-genetically modified rice, other main nutrients digestibility in the two rice have substantial equivalence.
Processing Conditions, Rice Properties, Health and Environment

Directory of Open Access Journals (Sweden)

Nobutaka Nakamura

2011-06-01

Full Text Available Rice is the staple food for nearly two-thirds of the world’s population. Food components and environmental load of rice depends on the rice form that is resulted by different processing conditions. Brown rice (BR, germinated brown rice (GBR and partially-milled rice (PMR contains more health beneficial food components compared to the well milled rice (WMR. Although the arsenic concentration in cooked rice depends on the cooking methods, parboiled rice (PBR seems to be relatively prone to arsenic contamination compared to that of untreated rice, if contaminated water is used for parboiling and cooking. A change in consumption patterns from PBR to untreated rice (non-parboiled, and WMR to PMR or BR may conserve about 43–54 million tons of rice and reduce the risk from arsenic contamination in the arsenic prone area. This study also reveals that a change in rice consumption patterns not only supply more food components but also reduces environmental loads. A switch in production and consumption patterns would improve food security where food grains are scarce, and provide more health beneficial food components, may prevent some diseases and ease the burden on the Earth. However, motivation and awareness of the environment and health, and even a nominal incentive may require for a method switching which may help in building a sustainable society.
Development of Ozone Technology Rice Storage Systems (OTRISS) for Quality Improvement of Rice Production

International Nuclear Information System (INIS)

Nur, M; Kusdiyantini, E; Wuryanti, W; Winarni, T A; Widyanto, S A; Muharam, H

2015-01-01

This research has been carried out by using ozone to address the rapidly declining quality of rice in storage. In the first year, research has focused on the rice storage with ozone technology for small capacity (e.g., household) and the medium capacity (e.g., dormitories, hospitals). Ozone was produced by an ozone generator with Dielectric Barrier Discharge Plasma (DBDP). Ozone technology rice storage system (OTRISS) is using ozone charateristic which is a strong oxidizer. Ozone have a short endurance of existence and then decompose, as a result produce oxygen and radicals of oxygen. These characteristics could kill microorganisms and pests, reduce air humidity and enrich oxygen. All components used in SPBTO assembled using raw materials available in the big cities in Indonesia. Provider of high voltage (High Voltage Power Supply, 40-70 kV, 23 KH, AC) is one of components that have been assembled and tested. Ozone generator is assembled with 7 reactors of Dielectric Barrier Discharge Plasma (DBDP). Rice container that have been prepared for OTRISS have adjusted so can be integrated with generator, power supply and blower to blow air. OTRISS with a capacity of 75 kg and 100 kg have been made and tested. The ability of ozone to eliminate bacteria and fungi have been tested and resulted in a decrease of microorganisms at 3 log CFU/g. Testing in food chemistry showed that ozone treatment of rice had not changed the chemical content that still meet the standard of chemical content and nutritional applicable to ISO standard milled rice. The results of this study are very likely to be used as an alternative to rice storage systems in warehouse. Test and scale-up is being carried out in a mini warehouse whose condition is mimicked to rice in National Rice Storage of Indonesia (Bulog) to ensure quality. Next adaptations would be installed in the rice storage system in the Bulog. (paper)
Microporous Silica Based Membranes for Desalination

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João C. Diniz da Costa

2012-09-01

Full Text Available This review provides a global overview of microporous silica based membranes for desalination via pervaporation with a focus on membrane synthesis and processing, transport mechanisms and current state of the art membrane performance. Most importantly, the recent development and novel concepts for improving the hydro-stability and separating performance of silica membranes for desalination are critically examined. Research into silica based membranes for desalination has focussed on three primary methods for improving the hydro-stability. These include incorporating carbon templates into the microporous silica both as surfactants and hybrid organic-inorganic structures and incorporation of metal oxide nanoparticles into the silica matrix. The literature examined identified that only metal oxide silica membranes have demonstrated high salt rejections under a variety of feed concentrations, reasonable fluxes and unaltered performance over long-term operation. As this is an embryonic field of research several target areas for researchers were discussed including further improvement of the membrane materials, but also regarding the necessity of integrating waste or solar heat sources into the final process design to ensure cost competitiveness with conventional reverse osmosis processes.
Mechanisms of UVB-resistance in rice: Cultivar differences in the sensitivity to UVB radiation in rice

International Nuclear Information System (INIS)

Hidema, J.

2001-01-01

In a study on the sensitivity to UVB radiation of rice cultivars of 5 Asian rice ecotypes, results showed that the rice cultivars widely varied in UVB sensitivity; among the Japanese rice cultivars, Sasanishiki was more resistant to UVB, while Norin 1 was less resistant; UV-sensitive Norin 1 was deficient in photorepair of cyclobutane pyrimidine dimers (UV-induced DNA damage), and the sensitivity to UVB radiation significantly correlated with deficient CPD photorepair; and that this deficiency in Norin 1 resulted from a functionally altered photolyase. The results suggest that photorepair capacity is a principal factor in determining UVB sensitivity in rice. The effects of supplemental UVB radiation on the growth and yield of Japanese rice cultivars under field conditions were also studied in Japan since 1993. The results indicate that supplemental UVB radiation had inhibitory effects on the growth and yield of rice. Furthermore, grain size was smaller with supplemental UVB radiation
Contribution of rice straw carbon to CH4 emission from rice paddies using 13C-enriched rice straw

Science.gov (United States)

Watanabe, Akira; Yoshida, Mariko; Kimura, Makoto

1998-04-01

It is generally recognized that the application of rice straw (RS) increases CH4 emission from rice paddies. To estimate the contribution of RS carbon to CH4 emission, a pot experiment was conducted using 13C-enriched RS. The percentage contributions of RS carbon to CH4 emission throughout the rice growth period were 10±1, 32±3, and 43±3% for the treatments with RS applied at the rates of 2, 4, and 6 g kg-1 soil, respectively. The increase in the rate of application of RS increased CH4 emission derived from both RS carbon and other carbon sources. The percentage contribution of RS carbon to CH4 emission was larger in the earlier period (maximum 96%) when the decomposition rate of RS was larger. After RS decomposition had slowed, CH4 emission derived from RS carbon decreased. However, the δ13C values of CH4 emitted from the pots with 13C-enriched RS applied at rates of 4 and 6 g kg-1 soil were significantly higher than those from the pots with natural RS until the harvesting stage. An increased atom-13C% of roots of rice plants growing in the pots with 6 g kg-1 of 13C-enriched RS at around the maximum tiller number stage and a decrease during the following 2 months suggested that rice plants assimilated RS carbon once and then released a portion of it. This supply of RS carbon from roots may be one of the sources of CH4 in the late period of rice growth.
Characterization and evaluation of rice blast resistance of Chinese indica hybrid rice parental lines

Directory of Open Access Journals (Sweden)

Yunyu Wu

2017-12-01

Full Text Available The development of resistant varieties and hybrid combinations has been the most effective and economical strategy to control blast disease caused by Magnaporthe oryzae. However, the distribution of major R genes and blast resistance characterization in hybrid rice parents has not been well investigated, resulting in their limited use in hybrid rice blast-resistance breeding. In the present study, 88 elite indica hybrid rice parental lines were evaluated with 30 isolates of M. oryzae collected from the main planting area of indica hybrid rice in China and were characterized for the presence of 11 major resistance genes using molecular markers. The pathogenicity assays showed that four types of hybrid rice parent line showed some resistance to M. oryzae. However, the proportions of highly resistant lines and the mean resistance frequency (RF varied among the four types, with resistance in decreasing order shown by three-line restorer lines, three-line maintainer lines, two-line sterile lines, and two-line restorer lines. All 88 hybrid rice parental lines carried more than one R gene, but none carried the R genes Pi1 and Pi2. Although Pid3 and Pi9 were present only in three-line restorer lines and Pigm only in three-line maintainer lines, the remaining six R genes (Pib, Pid2, Pi5, Pia, Pi54, and Pita were present in the four types of hybrid rice parent with significantly different distribution frequencies. The correlation between R genes and resistance reactions was investigated. The results are expected to provide useful information for rational utilization of major R genes in hybrid rice breeding programs. Keywords: Hybrid rice parental lines, Magnaporthe oryzae, Pi genes, Resistance evaluation, Molecular markers
Synthesis and application of silica gel modified with alkoxyalcohols. Alkoxyalcohol shushoku silica gel no gosei to riyo

Energy Technology Data Exchange (ETDEWEB)

Moriguchi, T.; Ishiguro, H.; Matsubara, Y.; Yoshihara, M.; Maeshima, T.; Ito, S. (Kinki University, Osaka (Japan). Faculty of Science and Engineering)

1991-08-20

Several kinds of silica gel modified by alkoxyalcohols were synthesized by refluxing and dehyration and the organic reactions were studied when these silica gels were used as the catalyst. It could be confirmed by FT-IR spectra, DTA and elementary analysis that alkoxylalcohols adhere to the surface of silica gels without any decomposition. The acetate was produced by using alkyl halides. It was found that the modified silica gels had clearly the catalytic action for the reaction with n-hexyl bromide and dibromoethane although unmodified silica gels did not show the catalytic action. The reducing reaction of carbonyl compounds was carried out. The reaction proceeded at 25 centigrade for acetophenone, cyclohexanone, 1-indanone and 2-octanone to produce the corresponding reduction products. 11 refs., 5 figs., 4 tabs.
Magnetic solid-phase extraction of triazine herbicides from rice using metal-organic framework MIL-101(Cr) functionalized magnetic particles.

Science.gov (United States)

Liang, Li; Wang, Xinghua; Sun, Ying; Ma, Pinyi; Li, Xinpei; Piao, Huilan; Jiang, Yanxiao; Song, Daqian

2018-03-01

The metal-organic framework (MOF) functionalized magnetic graphene oxide/mesoporous silica composites (Fe 3 O 4 @SiO 2 -GO/MIL-101(Cr)) were synthesized and utilized as magnetic solid-phase extraction (MSPE) adsorbent for the extraction of seven triazine herbicides (terbuthylazine, secbumeton, terbumeton, atraton, atrazine, prometon and trietazine) in rice samples. Several experimental parameters, including type and volume of extraction solvent, amount of MIL-101(Cr), extraction time, volume of desorption solvent and desorption time were investigated and optimized. The limits of detection (LODs) of seven triazine herbicides obtained by using the proposed MSPE method combined with high performance liquid chromatography (HPLC) were in the range of 0.010-0.080µgkg -1 . The recoveries of the triazine herbicides in spiked rice samples ranged from of 83.9-103.5% with the relative standard deviations lower than 8.7%. The intra and inter-day (n = 6) precisions for all triazine herbicides at the spiked level of 100.0µgkg -1 were 1.4-5.9% and 2.6-7.8%, respectively. Copyright © 2017 Elsevier B.V. All rights reserved.
Evaluation of Heavy Metals Contamination from Environment to Food Matrix by TXRF: The Case of Rice and Rice Husk

Directory of Open Access Journals (Sweden)

Fabjola Bilo

2015-01-01

Full Text Available This paper is devoted to the chemical analysis of contaminated soils of India and the rice grown in the same area. Total reflection X-ray fluorescence spectroscopy is a well-established technique for elemental chemical analysis of environmental samples, and it can be a useful tool to assess food safety. Metals uptake in rice crop grown in soils from different areas was studied. In this work soil, rice husk and rice samples were analyzed after complete solubilization of samples by microwave acid digestion. Heavy metals concentration detected in rice samples decreases in the following order: Mn > Zn > Cu > Ni > Pb > Cr. The metal content in rice husk was higher than in rice. This study suggests, for the first time, a possible role of heavy metals filter played by rice husk. The knowledge of metals sequestration capability of rice husk may promote some new management practices for rice cultivation to preserve it from pollution.
Innovation Chinese rice wine brewing technology by bi-acidification to exclude rice soaking process.

Science.gov (United States)

Wei, Xiao Lu; Liu, Shuang Ping; Yu, Jian Shen; Yu, Yong Jian; Zhu, Sheng Hu; Zhou, Zhi Lei; Hu, Jian; Mao, Jian

2017-04-01

As a traditional fermented alcoholic beverage of China, Chinese rice wine (CRW) had a long history of more than 5000 years. Rice soaking process was the most crucial step during CRW brewing process, because rice soaking quality directly determined the quality of CRW. However, rice soaking water would cause the eutrophication of water bodies and waste of water. The longer time of rice soaking, the higher the content of biogenic amine, and it would have a huge impact on human health. An innovation brewing technology was carried out to exclude the rice soaking process and the Lactobacillus was added to make up for the total acid. Compared to the traditional brewing technology, the new technology saved water resources and reduced environmental pollution. The concentration of biogenic amine was also decreased by 27.16%, which improving the security of the CRW. The esters increased led to more soft-tasted CRW and less aging time; the quality of CRW would be improved with less alcohol. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.
Effect of germination on the physicochemical and antioxidant characteristics of rice flour from three rice varieties from Nigeria.

Science.gov (United States)

Chinma, Chiemela Enyinnaya; Anuonye, Julian Chukwuemeka; Simon, Omotade Comfort; Ohiare, Raliat Ozavize; Danbaba, Nahemiah

2015-10-15

This study determined the effect of germination (48 h) on the physicochemical and antioxidant characteristics of rice flour from three rice varieties from Nigeria. Local rice varieties (Jamila, Jeep and Kwandala) were evaluated and compared to an improved variety (MR 219). Physicochemical and antioxidant properties of flours were determined using standard methods. Protein, magnesium, phosphorus, potassium and antioxidant properties of rice flours increased after germination while phytic acid and total starch contents decreased. Foaming capacity and stability of rice flours increased after germination. Germination resulted to changes in pasting and thermal characteristics of rice flours. Germinated rice flours had better physicochemical and antioxidant properties with reduced phytic acid and starch contents compared to MR 219, which can be utilized as functional ingredients in the preparation of rice-based products. Copyright © 2015 Elsevier Ltd. All rights reserved.
Dolce Vita in the Rice Paddy - Characterization of weedy rice groups in Northern Italy and investigation of their evolutionary origins

OpenAIRE

Grimm, Annabelle

2014-01-01

The thesis deals with the topic of the invasive rice form called weedy rice or red rice. Studies focused on the geographical area of Italy. Different populations of weedy rice in Italy were genetically characterized. The evolutionary origins of different weedy rice groups were investigated using molecular, morphological and physiological methods. Invasion of wild rice as well as de-domestication of cultivars could be identified as evolutionary sources of weedy rice in Northern Italy.
SCC modification by use of amorphous nano-silica

NARCIS (Netherlands)

Quercia Bianchi, G.; Spiesz, P.R.; Hüsken, G.; Brouwers, H.J.H.

2014-01-01

In this study two different types of nano-silica (nS) were applied in self-compacting concrete (SCC), both having similar particle size distributions (PSD), but produced through two different processes: fumed powder silica and precipitated silica in colloidal suspension. The influence of nano-silica
Agmatine attenuates silica-induced pulmonary fibrosis.

Science.gov (United States)

El-Agamy, D S; Sharawy, M H; Ammar, E M

2014-06-01

There is a large body of evidence that nitric oxide (NO) formation is implicated in mediating silica-induced pulmonary fibrosis. As a reactive free radical, NO may not only contribute to lung parenchymal tissue injury but also has the ability to combine with superoxide and form a highly reactive toxic species peroxynitrite that can induce extensive cellular toxicity in the lung tissues. This study aimed to explore the effect of agmatine, a known NO synthase inhibitor, on silica-induced pulmonary fibrosis in rats. Male Sprague Dawley rats were treated with agmatine for 60 days following a single intranasal instillation of silica suspension (50 mg in 0.1 ml saline/rat). The results revealed that agmatine attenuated silica-induced lung inflammation as it decreased the lung wet/dry weight ratio, protein concentration, and the accumulation of the inflammatory cells in the bronchoalveolar lavage fluid. Agmatine showed antifibrotic activity as it decreased total hydroxyproline content of the lung and reduced silica-mediated lung inflammation and fibrosis in lung histopathological specimen. In addition, agmatine significantly increased superoxide dismutase (p Agmatine also reduced silica-induced overproduction of pulmonary nitrite/nitrate as well as tumor necrosis factor α. Collectively, these results demonstrate the protective effects of agmatine against the silica-induced lung fibrosis that may be attributed to its ability to counteract the NO production, lipid peroxidation, and regulate cytokine effects. © The Author(s) 2014.

21 CFR 137.350 - Enriched rice.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Enriched rice. 137.350 Section 137.350 Food and... Related Products § 137.350 Enriched rice. (a) The foods for which definitions and standards of identity are prescribed by this section are forms of milled rice (except rice coated with talc and glucose and...
Bioethanol production from rice straw residues

Directory of Open Access Journals (Sweden)

Elsayed B. Belal

2013-01-01

Full Text Available A rice straw -cellulose utilizing mold was isolated from rotted rice straw residues. The efficient rice straw degrading microorganism was identified as Trichoderma reesei. The results showed that different carbon sources in liquid culture such as rice straw, carboxymethyl cellulose, filter paper, sugar cane bagasse, cotton stalk and banana stalk induced T. reesei cellulase production whereas glucose or Potato Dextrose repressed the synthesis of cellulase. T. reesei cellulase was produced by the solid state culture on rice straw medium. The optimal pH and temperature for T. reesei cellulase production were 6 and 25 ºC, respectively. Rice straw exhibited different susceptibilities towards cellulase to their conversion to reducing sugars. The present study showed also that, the general trend of rice straw bioconversion with cellulase was more than the general trend by T. reesei. This enzyme effectively led to enzymatic conversion of acid, alkali and ultrasonic pretreated cellulose from rice straw into glucose, followed by fermentation into ethanol. The combined method of acid pretreatment with ultrasound and subsequent enzyme treatment resulted the highest conversion of lignocellulose in rice straw to sugar and consequently, highest ethanol concentration after 7 days fermentation with S. cerevisae yeast. The ethanol yield in this study was about 10 and 11 g.L-1.
Consumer Preferences and Buying Criteria in Rice: A Study to Identify Market Strategy for Thailand Jasmine Rice Export

NARCIS (Netherlands)

Suwannaporn, P.; Linnemann, A.R.

2008-01-01

Rice consumption per capita in many Asian countries decreased, but it is consumed more in non-rice-eating countries. This study aimed to investigate consumer preferences and attitudes toward Jasmine rice among consumers in target rice export countries to identify opportunities and strategic
Benthic macroinvertebrates in Italian rice fields

Directory of Open Access Journals (Sweden)

Daniela Lupi

2013-02-01

Full Text Available Rice fields can be considered man-managed temporary wetlands. Five rice fields handled with different management strategies, their adjacent channels, and a spring were analysed by their benthic macroinvertebrate community to i evaluate the role of rice agroe- cosystem in biodiversity conservation; ii find indicator species which can be used to compare the ecological status of natural wetlands with rice agroecosystems; and iii find the influence of environmental variables on biodiversity. Different methods of data analysis with increasing degree of complexity – from diversity index up to sophisticated multivariate analysis – were used. The investigation provided a picture of benthic macroinvertebrates inhabiting rice agroecosystems where 173 taxa were identified, 89 of which detected in rice paddies. Among them, 4 phyla (Mollusca, Annelida, Nematomorpha, and Arthropoda, 8 classes (Bivalvia, Gastropoda, Oligochaeta, Hirudinea, Gordioida, Insecta, Branchiopoda, and Malacostraca, 24 orders, 68 families, 127 genera and 159 species have been found. Ten threatened and 3 invasive species were detected in the habitats examined. The information obtained by the different methods of data analysis allowed a more comprehensive view on the value of the components of rice agroecosystems. Data analyses highlighted significant differences between habitats (feeding channel and rice field, with higher diversity observed in channels, and emphasised the role of the water chemical-physical parameters. The period of water permanence in rice fields resulted to be only one of the factors influencing the community of benthic macroinvertebrates. The presence of rare/endangered species allowed characterising some stations, but it was less informative about management strategies in rice paddies because most of these species were absent in rice fields.
Study of Rice Marketing System in Iran

OpenAIRE

Feizabadi, Yaser

2011-01-01

Rice comes second after wheat in Iran`s food consumption economy. Rising population and recent growth in GDP has made Iran one of the greatest rice importer countries all over the world. That is why rice marketing has always been a controversial issue in Iran`s agricultural economics. To study rice marketing system in Iran, this paper aims to calculate rice marketing margin, market efficiency and marketing cost coefficient in seaside Mazandaran province( where 70 percent of domestic rice prod...
Micronutrient-fortified rice can increase hookworm infection risk

DEFF Research Database (Denmark)

de Gier, Brechje; Campos Ponce, Maiza; Perignon, Marlene

2016-01-01

or inflammation after iron supplementation. OBJECTIVE: To study effects of micronutrient-fortified rice on hookworm infection in Cambodian schoolchildren. METHODS: A double-blinded, cluster-randomized trial was conducted in 16 Cambodian primary schools partaking in the World Food Program school meal program....... Three types of multi-micronutrient fortified rice were tested against placebo rice within the school meal program: UltraRice_original, UltraRice_improved and NutriRice. Four schools were randomly assigned to each study group (placebo n = 492, UltraRice_original n = 479, UltraRice_improved n = 500, NutriRice.......6%, but differed considerably among schools (range 0%- 48.1%).Micronutrient-fortified rice significantly increased risk of new hookworm infection. This effect was modified by baseline hookworm prevalence at the school; hookworm infection risk was increased by all three types of fortified rice in schools where...
All-silica nanofluidic devices for DNA-analysis fabricated by imprint of sol-gel silica with silicon stamp

DEFF Research Database (Denmark)

Mikkelsen, Morten Bo Lindholm; Letailleur, Alban A; Søndergård, Elin

2011-01-01

We present a simple and cheap method for fabrication of silica nanofluidic devices for single-molecule studies. By imprinting sol-gel materials with a multi-level stamp comprising micro- and nanofeatures, channels of different depth are produced in a single process step. Calcination of the imprin......We present a simple and cheap method for fabrication of silica nanofluidic devices for single-molecule studies. By imprinting sol-gel materials with a multi-level stamp comprising micro- and nanofeatures, channels of different depth are produced in a single process step. Calcination...... of the imprinted hybrid sol-gel material produces purely inorganic silica, which has very low autofluorescence and can be fusion bonded to a glass lid. Compared to top-down processing of fused silica or silicon substrates, imprint of sol-gel silica enables fabrication of high-quality nanofluidic devices without...
Dynamic adsorption of mixtures of Rhodamine B, Pb (II), Cu (II) and Zn(II) ions on composites chitosan-silica-polyethylene glycol membrane

Science.gov (United States)

Mahatmanti, F. W.; Rengga, W. D. P.; Kusumastuti, E.; Nuryono

2018-04-01

The adsorption of a solution mixture of Rhodamine B, Pb (II), Cu (II) and Zn(II) was studied using dynamic methods employing chitosan-silica-polyethylene glycol (Ch/Si/P) composite membrane as an adsorptive membrane. The composite Ch/Si/P membrane was prepared by mixing a chitosan-based membrane with silica isolated from rice husk ash (ASP) and polyethylene glycol (PEG) as a plasticizer. The resultant composite membrane was a stronger and more flexible membrane than the original chitosan-based membrane as indicated by the maximum percentage of elongation (20.5 %) and minimum Young’s Modulus (80.5 MPa). The composite membrane also showed increased mechanical and hydrophilic properties compared to the chitosan membranes. The membrane was used as adsorption membrane for Pb (II), Cu (II), Cd (II) ions and Rhodamine B dyes in a dynamic system where the permeation and selectivity were determined. The permeation of the components was observed to be in the following order: Rhodamine B > Cd (II) > Pb (II) > Cu (II) whereas the selectivity was shown to decrease the order of Cu (II) > Pb (II) > Cd (II) > Rhodamine B.
Degradability and Clearance of Silicon, Organosilica, Silsesquioxane, Silica Mixed Oxide, and Mesoporous Silica Nanoparticles

KAUST Repository

Croissant, Jonas G.

2017-01-13

The biorelated degradability and clearance of siliceous nanomaterials have been questioned worldwide, since they are crucial prerequisites for the successful translation in clinics. Typically, the degradability and biocompatibility of mesoporous silica nanoparticles (MSNs) have been an ongoing discussion in research circles. The reason for such a concern is that approved pharmaceutical products must not accumulate in the human body, to prevent severe and unpredictable side-effects. Here, the biorelated degradability and clearance of silicon and silica nanoparticles (NPs) are comprehensively summarized. The influence of the size, morphology, surface area, pore size, and surface functional groups, to name a few, on the degradability of silicon and silica NPs is described. The noncovalent organic doping of silica and the covalent incorporation of either hydrolytically stable or redox- and enzymatically cleavable silsesquioxanes is then described for organosilica, bridged silsesquioxane (BS), and periodic mesoporous organosilica (PMO) NPs. Inorganically doped silica particles such as calcium-, iron-, manganese-, and zirconium-doped NPs, also have radically different hydrolytic stabilities. To conclude, the degradability and clearance timelines of various siliceous nanomaterials are compared and it is highlighted that researchers can select a specific nanomaterial in this large family according to the targeted applications and the required clearance kinetics.
Trace gas fluxes from intensively managed rice and soybean fields across three growing seasons in the Brazilian Amazon

Science.gov (United States)

R.C. Oliveira Junior; Michael Keller; P. Crill; T. Beldini; J. Van Haren; P. Camargo

2015-01-01

The emission of gases that may potentially intensify the greenhouse effect has received special attention due to their ability to raise global temperatures and possibly modify conditions for life on earth. The objectives of this study were the quantification of trace gas flux (N2O, CO2 and CH4) in soils of the lower Amazon basin that are planted with rice and soybean,...
Brewers’ Rice: A By-Product from Rice Processing Provides Natural Hepatorenal Protection in Azoxymethane-Induced Oxidative Stress in Rats

Directory of Open Access Journals (Sweden)

Bee Ling Tan

2015-01-01

Full Text Available Brewers’ rice, which is known locally as temukut, is a mixture of broken rice, rice bran, and rice germ. Our present study was designed to identify the effect of brewers’ rice on the attenuation of liver and kidney damage induced by azoxymethane (AOM. Alanine transaminase (ALT, alkaline phosphatase (ALP, aspartate transaminase (AST, creatinine, and urea were evaluated to understand potential hepatoprotective effects and the ability of brewers’ rice to attenuate kidney pathology induced by AOM treatment. Liver and kidney tissues were evaluated by hematoxylin and eosin (H&E staining. Overall analyses revealed that brewers’ rice improved the levels of serum markers in a manner associated with better histopathological outcomes, which indicated that brewers’ rice could enhance recovery from hepatocyte and kidney damage. Taken together, these results suggest that brewers’ rice could be used in future applications to combat liver and kidney disease.
Functionalization of silica nanoparticles for polypropylene nanocomposites applications

International Nuclear Information System (INIS)

Bracho, Diego; Palza, Humberto; Quijada, Raul; Dougnac, Vivianne

2011-01-01

Synthetic silica nanospheres of different diameters produced via the sol-gel method were used in order to enhance the barrier properties of the polypropylene-silica nanocomposites. Modification of the silica surface by reaction with organic chlorosilanes was performed in order to improve the particles interaction with the polypropylene matrix and its dispersion. Unmodified and modified silica nanoparticles were characterized using electronic microscopy (TEM), elemental analysis, thermo gravimetric analysis (TGA), and solid state nuclear magnetic resonance (NMR) spectroscopy. Preliminary permeability tests of the polymer-silica nanocomposite films showed no significant change at low particles load (3 wt%) regardless its size or surface functionality, mainly because of the low aspect ratio of the silica nanospheres. However, it is expected that at a higher concentration of silica particles differences will be observed. (author)
Toughening Mechanisms in Silica-Filled Epoxy Nanocomposites

Science.gov (United States)

Patel, Binay S.

Epoxies are widely used as underfill resins throughout the microelectronics industry to mechanically couple and protect various components of flip-chip assemblies. Generally rigid materials largely surround underfill resins. Improving the mechanical and thermal properties of epoxy resins to better match those of their rigid counterparts can help extend the service lifetime of flip-chip assemblies. Recently, researchers have demonstrated that silica nanoparticles are effective toughening agents for lightly-crosslinked epoxies. Improvements in the fracture toughness of silica-filled epoxy nanocomposites have primarily been attributed to two toughening mechanisms: particle debonding with subsequent void growth and matrix shear banding. Various attempts have been made to model the contribution of these toughening mechanisms to the overall fracture energy observed in silica-filled epoxy nanocomposites. However, disparities still exist between experimental and modeled fracture energy results. In this dissertation, the thermal, rheological and mechanical behavior of eight different types of silica-filled epoxy nanocomposites was investigated. Each nanocomposite consisted of up to 10 vol% of silica nanoparticles with particle sizes ranging from 20 nm to 200 nm, with a variety of surface treatments and particle structures. Fractographical analysis was conducted with new experimental approaches in order to accurately identify morphological evidence for each proposed toughening mechanism. Overall, three major insights into the fracture behavior of real world silica-filled epoxy nanocomposites were established. First, microcracking was observed as an essential toughening mechanism in silica-filled epoxy nanocomposites. Microcracking was observed on the surface and subsurface of fractured samples in each type of silica-filled epoxy nanocomposite. The additional toughening contribution of microcracking to overall fracture energy yielded excellent agreement between experimental
The impact of seasonal rice price changes on rice self-consumption in farm household of rural Java

Science.gov (United States)

Ani, S. W.; Antriyandarti, E.

2018-03-01

Seasonal rice price changes are very volatile and not predictable. This price changes have a heterogeneous impact on public consumption. The problem of seasonal rice price changes is not only experienced by consumers, but also in the farmers side as producers. The objective of this study is to provide a detail overview and description of the changing seasonal rice self-consumption of farm households in rural Java in response to seasonal rice price changes and income shocks to anticipate seasonal scarcity. This paper constructs a theoretical model to address such seasonality of food deprivation by using one year of seasonally farm household panel data, empirically tests the extent to which farmers in rural Java can smooth their rice self-consumption from season to season in response to income shocks. The result shows that rice farmers increase their rice self-consumption when prices are high.
Polar silica-based stationary phases. Part II- Neutral silica stationary phases with surface bound maltose and sorbitol for hydrophilic interaction liquid chromatography.

Science.gov (United States)

Rathnasekara, Renuka; El Rassi, Ziad

2017-07-28

Two neutral polyhydroxylated silica bonded stationary phases, namely maltose-silica (MALT-silica) and sorbitol-silica (SOR-silica), have been introduced and chromatographically characterized in hydrophilic interaction liquid chromatography (HILIC) for a wide range of polar compounds. The bonding of the maltose and sorbitol to the silica surface was brought about by first converting bare silica to an epoxy-activated silica surface via reaction with γ-glycidoxypropyltrimethoxysilane (GPTMS) followed by attaching maltose and sorbitol to the epoxy surface in the presence of the Lewis acid catalyst BF 3 .ethereate. Both silica based columns offered the expected retention characteristics usually encountered for neutral polar surface. The retention mechanism is majorly based on solute' differential partitioning between an organic rich hydro-organic mobile phase (e.g., ACN rich mobile phase) and an adsorbed water layer on the surface of the stationary phase although additional hydrogen bonding was also responsible in some cases for solute retention. The MALT-silica column proved to be more hydrophilic and offered higher retention, separation efficiency and resolution than the SOR-silica column among the tested polar solutes such as derivatized mono- and oligosaccharides, weak phenolic acids, cyclic nucleotide monophosphate and nucleotide-5'-monophosphates, and weak bases, e.g., nucleobases and nucleosides. Copyright © 2017 Elsevier B.V. All rights reserved.
Diversity of global rice markets and the science required for consumer-targeted rice breeding.

Directory of Open Access Journals (Sweden)

Mariafe Calingacion

Full Text Available With the ever-increasing global demand for high quality rice in both local production regions and with Western consumers, we have a strong desire to understand better the importance of the different traits that make up the quality of the rice grain and obtain a full picture of rice quality demographics. Rice is by no means a 'one size fits all' crop. Regional preferences are not only striking, they drive the market and hence are of major economic importance in any rice breeding / improvement strategy. In this analysis, we have engaged local experts across the world to perform a full assessment of all the major rice quality trait characteristics and importantly, to determine how these are combined in the most preferred varieties for each of their regions. Physical as well as biochemical characteristics have been monitored and this has resulted in the identification of no less than 18 quality trait combinations. This complexity immediately reveals the extent of the specificity of consumer preference. Nevertheless, further assessment of these combinations at the variety level reveals that several groups still comprise varieties which consumers can readily identify as being different. This emphasises the shortcomings in the current tools we have available to assess rice quality and raises the issue of how we might correct for this in the future. Only with additional tools and research will we be able to define directed strategies for rice breeding which are able to combine important agronomic features with the demands of local consumers for specific quality attributes and hence, design new, improved crop varieties which will be awarded success in the global market.
Diversity of Global Rice Markets and the Science Required for Consumer-Targeted Rice Breeding

Science.gov (United States)

Calingacion, Mariafe; Laborte, Alice; Nelson, Andrew; Resurreccion, Adoracion; Concepcion, Jeanaflor Crystal; Daygon, Venea Dara; Mumm, Roland; Reinke, Russell; Dipti, Sharifa; Bassinello, Priscila Zaczuk; Manful, John; Sophany, Sakhan; Lara, Karla Cordero; Bao, Jinsong; Xie, Lihong; Loaiza, Katerine; El-hissewy, Ahmad; Gayin, Joseph; Sharma, Neerja; Rajeswari, Sivakami; Manonmani, Swaminathan; Rani, N. Shobha; Kota, Suneetha; Indrasari, Siti Dewi; Habibi, Fatemeh; Hosseini, Maryam; Tavasoli, Fatemeh; Suzuki, Keitaro; Umemoto, Takayuki; Boualaphanh, Chanthkone; Lee, Huei Hong; Hung, Yiu Pang; Ramli, Asfaliza; Aung, Pa Pa; Ahmad, Rauf; Wattoo, Javed Iqbal; Bandonill, Evelyn; Romero, Marissa; Brites, Carla Moita; Hafeel, Roshni; Lur, Huu-Sheng; Cheaupun, Kunya; Jongdee, Supanee; Blanco, Pedro; Bryant, Rolfe; Thi Lang, Nguyen; Hall, Robert D.; Fitzgerald, Melissa

2014-01-01

With the ever-increasing global demand for high quality rice in both local production regions and with Western consumers, we have a strong desire to understand better the importance of the different traits that make up the quality of the rice grain and obtain a full picture of rice quality demographics. Rice is by no means a ‘one size fits all’ crop. Regional preferences are not only striking, they drive the market and hence are of major economic importance in any rice breeding / improvement strategy. In this analysis, we have engaged local experts across the world to perform a full assessment of all the major rice quality trait characteristics and importantly, to determine how these are combined in the most preferred varieties for each of their regions. Physical as well as biochemical characteristics have been monitored and this has resulted in the identification of no less than 18 quality trait combinations. This complexity immediately reveals the extent of the specificity of consumer preference. Nevertheless, further assessment of these combinations at the variety level reveals that several groups still comprise varieties which consumers can readily identify as being different. This emphasises the shortcomings in the current tools we have available to assess rice quality and raises the issue of how we might correct for this in the future. Only with additional tools and research will we be able to define directed strategies for rice breeding which are able to combine important agronomic features with the demands of local consumers for specific quality attributes and hence, design new, improved crop varieties which will be awarded success in the global market. PMID:24454799
Assessment of Rice Associated Bacterial Ability to Enhance Rice Seed Germination and Rice Growth Promotion

Directory of Open Access Journals (Sweden)

R. Gholamalizadeh

2017-08-01

Full Text Available ABSTRACT The application of beneficial bacteria has recently been used for sustainable agriculture. In current research, 71 bacterial isolates were obtained from rice plant and the rhizosphere soil of different paddy fields in Guilan province, Iran. After primitive investigation, 40 bacteria with typical predominant characteristics were selected. By PCR-RFLP of their 16S r-DNA gene, 8 Operational Taxonomic Units (OTUs totally consisted of 33 isolates were obtained. From all of them, 8 isolates were selected for rice seed germination experiment, then, effective isolates were used for pot experiment to evaluate their ability for promoting rice growth. All of them were able to increase rice growth and yield, but in different potential. These tested isolates were identified as Alcaligenes faecalis (DEp8, O1R4, Pantoea ananatis (AEn1, Bacillus vietnamensis (MR5, Bacillus idriensis (MR2 and Stenotrophomonas maltophilia by partial sequencing of their 16S r-DNA gene. Among them, AEn1 and MR5 produced indole-3- acetic acid (IAA in larger amounts than the other isolates and the isolates AEn1 and O1R4 were able to solubilize phosphate in higher amounts. According to the results obtained, it can be concluded that AEn1, O1R4 and MR5 can be considered as bacterial inoculants to use as alternatives for chemical fertilizers.
Magnetic core-shell silica particles

NARCIS (Netherlands)

Claesson, E.M.

2007-01-01

This thesis deals with magnetic silica core-shell colloids and related functionalized silica structures. Synthesis routes have been developed and optimized. The physical properties of these colloids have been investigated, such as the magnetic dipole moment, dipolar structure formation and
Effect of transgenic Bacillus thuringiensis rice lines on mortality and feeding behavior of rice stem borers (Lepidoptera: Crambidae).

Science.gov (United States)

Chen, Hao; Zhang, Guoan; Zhang, Qifa; Lin, Yongjun

2008-02-01

Ten transgenic Bacillus thuringiensis Bt rice, Oryza sativa L., lines with different Bt genes (two Cry1Ac lines, three Cry2A lines, and five Cry9C lines) derived from the same variety Minghui 63 were evaluated in both the laboratory and the field. Bioassays were conducted by using the first instars of two main rice lepidopteran insect species: yellow stem borer, Scirpophaga incertulas (Walker) and Asiatic rice borer, Chilo suppressalis (Walker). All transgenic lines exhibited high toxicity to these two rice borers. Field evaluation results also showed that all transgenic lines were highly insect resistant with both natural infestation and manual infestation of the neonate larvae of S. incertulas compared with the nontransformed Minghui63. Bt protein concentrations in leaves of 10 transgenic rice lines were estimated by the sandwich enzyme-linked immunosorbent assay. The cry9C gene had the highest expression level, next was cry2A gene, and the cry1Ac gene expressed at the lowest level. The feeding behavior of 7-d-old Asiatic rice borer to three classes of Bt transgenic rice lines also was detected by using rice culm cuttings. The results showed that 7-d-old larvae of Asiatic rice borer have the capacity to distinguish Bt and non-Bt culm cuttings and preferentially fed on non-Bt cuttings. When only Bt culm cuttings with three classes of different Bt proteins (CrylAc, Cry2A, and Cry9C) were fed, significant distribution difference of 7-d-old Asiatic rice borer in culm cuttings of different Bt proteins also was found. In the current study, we evaluate different Bt genes in the same rice variety in both the laboratory and the field, and also tested feeding behavior of rice insect to these Bt rice. These data are valuable for the further development of two-toxin Bt rice and establishment of appropriate insect resistance management in the future.

Rice Yellow Mottle Virus stress responsive genes from susceptible and tolerant rice genotypes

Directory of Open Access Journals (Sweden)

Siré Christelle

2008-03-01

Full Text Available Abstract Background The effects of viral infection involve concomitant plant gene variations and cellular changes. A simple system is required to assess the complexity of host responses to viral infection. The genome of the Rice yellow mottle virus (RYMV is a single-stranded RNA with a simple organisation. It is the most well-known monocotyledon virus model. Several studies on its biology, structure and phylogeography have provided a suitable background for further genetic studies. 12 rice chromosome sequences are now available and provide strong support for genomic studies, particularly physical mapping and gene identification. Results The present data, obtained through the cDNA-AFLP technique, demonstrate differential responses to RYMV of two different rice cultivars, i.e. susceptible IR64 (Oryza sativa indica, and partially resistant Azucena (O. s. japonica. This RNA profiling provides a new original dataset that will enable us to gain greater insight into the RYMV/rice interaction and the specificity of the host response. Using the SIM4 subroutine, we took the intron/exon structure of the gene into account and mapped 281 RYMV stress responsive (RSR transcripts on 12 rice chromosomes corresponding to 234 RSR genes. We also mapped previously identified deregulated proteins and genes involved in partial resistance and thus constructed the first global physical map of the RYMV/rice interaction. RSR transcripts on rice chromosomes 4 and 10 were found to be not randomly distributed. Seven genes were identified in the susceptible and partially resistant cultivars, and transcripts were colocalized for these seven genes in both cultivars. During virus infection, many concomitant plant gene expression changes may be associated with host changes caused by the infection process, general stress or defence responses. We noted that some genes (e.g. ABC transporters were regulated throughout the kinetics of infection and differentiated susceptible and
Rice agroecosystem and the maintenance of biodiversity

International Nuclear Information System (INIS)

Ahyaudin Ali

2002-01-01

Rice fields are a special type of wetland. They are shallow, constantly disturbed and experience extremes in temperature and dissolved oxygen content. They receive nutrients in the form of fertilizers during rice cultivation. Rice fields; support a variety of flora and fauna that have adapted and adjusted themselves to the extreme conditions. Since rice fields also support populations of wild fish, rice?fish integration should be done in order to optimize land use and provide supplementary income to farmers. Rice?fish farming encourages farmers to judiciously apply pesticides and herbicides in their fields thus helping to control excessive and unwarranted use of these chemicals. Rice fields also support many migratory and nonmigratory bird species and provides habitat for small mammals. Thus the rice agroecosystem helps to maintain aquatic biodiversity. The Muda rice agroecosystem consists of a troika of interconnected ecosystems. The troika consisting of reservoirs, the connecting network of canals and the rice fields; should be investigated further. This data is needed for informed decision-making concerning development and management of the system so that productivity and biodiversity can be maintained and sustained. (Author)
Uptake of C-14 tagged acetate by rice in a paddy soil-to-rice plant system

Energy Technology Data Exchange (ETDEWEB)

Ishii, Nobuyoshi; Tagami, Keiko; Uchida, Shigeo [Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage, Chiba 263-8555 (Japan)

2014-07-01

Geological disposal of Transuranic (TRU) waste is planned to avoid radiation exposure to the public. One of the dominant nuclides contributing to the dose from TRU waste is C-14, which is long-lived and has very poor sorption properties on natural geological media. Therefore, there are some concerns regarding possible migration of C-14 to the living environments. For the public health safety, it is necessary to clarify pathways of C-14 to human beings in the environment. Intake of C-14 from food source is one of important pathways. In the present study, we examined transfer of C-14 to various parts of rice plant in a paddy soil-to-rice plant system. Rice seedlings in Wagner pots (n=12) were grown for about two months from 7 May 2012 under natural light. The grown plants were moved to a closed chamber on 5 July 2012. The rice plants were grown without water supply from 5 July 2012, and then one liter of C-14 tagged acetate (1.85 MBq) was supplied to the rice plants in the spiked group (n=8) just once on 9 July 2012. For the rice plants in the control group (n=4), uncontaminated water was supplied. These rice plants were air-dried after a harvest on 23 August 2012 and divided into four parts: white rice, bran, rice husk, and the stem and leaf part. The activities of C-14 in the divided parts and air-dried soil samples were determined with a liquid scintillation counting system. Radiocarbon was detected even in the rice plants of the control group. However, the C-14 activity in the soil of the control group was less than the detection limit (1.0 Bq/g). The C-14 activities for the control group decreased in the order of rice husk, bran, white rice, and the stem and leaf part. The detection of C-14 in the control group may be caused by the release of C-14 tagged carbon dioxide from the spiked group. That is, C-14 tagged acetate was converted to carbon dioxide by microbial activity in the spiked group, and then some of the released carbon dioxide was assimilated into
Performance of rice husk ash produced using a new technology as a mineral admixture in concrete

International Nuclear Information System (INIS)

Nehdi, M.; Duquette, J.; El Damatty, A.

2003-01-01

This article investigates the use of a new technique for the controlled combustion of Egyptian rice husk to mitigate the environmental concerns associated with its uncontrolled burning and provide a supplementary cementing material for the local construction industry. The reactor used provides efficient combustion of rice husk in a short residency time via the suspension of processed particles by jets of a process air stream that is forced though stationary angled blades at high velocity. Investigations on the rice husk ash (RHA) thus produced included oxide analysis, X-ray diffraction, carbon content, grindability, water demand, pozzolanic activity index, surface area, and particle size distribution measurements. In addition, concrete mixtures incorporating various proportions of silica fume (SF) and Egyptian RHA (EG-RHA) produced at different combustion temperatures were made and compared. The workability, superplasticizer and air-entraining admixture requirements, and compressive strength at various ages of these concrete mixtures were evaluated, and their resistance to rapid chloride penetrability and deicing salt surface scaling were examined. Test results indicate that contrary to RHA produced using existing technology, the superplasticizer and air-entraining agent requirements did not increase drastically when the RHA developed in this study was used. Compressive strengths achieved by concrete mixtures incorporating the new RHA exceeded those of concretes containing similar proportions of SF. The resistance to surface scaling of RHA concrete was better than that of concrete containing similar proportions of SF. While the chloride penetrability was substantially decreased by RHA, it remained slightly higher than that achieved by SF concrete
Comparison of the concentrations of metal elements and isotopes of lead found in rice and rice bran.

Science.gov (United States)

Dai, Shouhui; Yang, Hui; Yang, Lan; Wang, Fuhua; Du, Ruiying; Wen, Dian

2014-08-01

Very few studies have investigated the difference in the distribution of metal elements between rice and rice bran samples. In this study, the concentrations of 27 metal elements (Li, Be, Na, Mg, Al, K, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Ag, Cd, Cs, Ba, Tl, Pb, and U) in 56 polished rice and their corresponding bran samples were determined. A significant difference in concentrations of all elements except Ag and Cd was found between rice and bran (P rice ratios of 1.21 to 36.3. High concentrations of metal elements, especially that of the heavy metal Cr, in bran samples present a potential safety issue for bran products, such as food and feed containing bran. Pb isotope ((204)Pb, (206)Pb, (207)Pb, and (208)Pb) ratios also were determined. The (206)Pb/(207)Pb and (208)Pb/(207)Pb ratios in bran were generally higher than those in rice (P rice and bran samples were distinctly different from each other, indicating that Pb isotope composition is an effective for discriminating between bran and rice samples.
Evaluation of Rice Resistance to Southern Rice Black-Streaked Dwarf Virus and Rice Ragged Stunt Virus through Combined Field Tests, Quantitative Real-Time PCR, and Proteome Analysis.

Science.gov (United States)

Wang, Zhenchao; Yu, Lu; Jin, Linhong; Wang, Wenli; Zhao, Qi; Ran, Longlu; Li, Xiangyang; Chen, Zhuo; Guo, Rong; Wei, Yongtian; Yang, Zhongcheng; Liu, Enlong; Hu, Deyu; Song, Baoan

2017-02-22

Diseases caused by southern rice black-streaked dwarf virus (SRBSDV) and rice ragged stunt virus (RRSV) considerably decrease grain yield. Therefore, determining rice cultivars with high resistance to SRBSDV and RRSV is necessary. In this study, rice cultivars with high resistance to SRBSDV and RRSV were evaluated through field trials in Shidian and Mangshi county, Yunnan province, China. SYBR Green I-based quantitative real-time polymerase chain reaction (qRT-PCR) analysis was used to quantitatively detect virus gene expression levels in different rice varieties. The following parameters were applied to evaluate rice resistance: acre yield (A.Y.), incidence of infected plants (I.I.P.), virus load (V.L.), disease index (D.I.), and insect quantity (I.Q.) per 100 clusters. Zhongzheyou1 (Z1) and Liangyou2186 (L2186) were considered the most suitable varieties with integrated higher A.Y., lower I.I.P., V.L., D.I. and I.Q. In order to investigate the mechanism of rice resistance, comparative label-free shotgun liquid chromatography tandem-mass spectrometry (LC-MS/MS) proteomic approaches were applied to comprehensively describe the proteomics of rice varieties' SRBSDV tolerance. Systemic acquired resistance (SAR)-related proteins in Z1 and L2186 may result in the superior resistance of these varieties compared with Fengyouxiangzhan (FYXZ).
PDC bit selection to drill the Brazilian pre-salt heterogeneous carbonates; Selecao de broca PDC para a perfuracao dos carbonatos heterogeneos do pre-sal brasileiro

Energy Technology Data Exchange (ETDEWEB)

Lima, Araken Dumont Ramos; Tocantins, Joao Pedro Tourinho [Schlumberger, Rio de Janeiro, RJ (Brazil)

2012-07-01

The well drilling operation to access the oil reserves of the Brazilian pre-salt find their highest challenge in the rock reservoir, which is formed from organic limestone and other sediments, and it can have different heterogeneous features that are hostile to drilling. Those features such as the silica nodules increase the rock formation strength and abrasiveness that together with the PDC bit vibrations generated during the rock cutting reduce the life of the cutting structure to a few meters. Because of these conditions, the development of more stable bits, with very low lateral and torsional vibration levels and with more strength PDC, has been one oil industry challenges to drill the pre-salt limestone with silica. This paper aims to present a dynamic comparative analysis between three PDC bits, called BR1, BR2 and BR3, of different generations, selected to drill a well design in a limestone heterogeneous and homogeneous (without silica nodules). This analysis was performed with dynamic three dimensional finite elements software, which considers the interaction between the bit cutter structure and the rock to be drilled, used to design bits, reamers and BHA (Bottom Hole Assembly). (author)
Determination of Tinopal CBS-X in rice papers and rice noodles using HPLC with fluorescence detection and LC-MS/MS.

Science.gov (United States)

Ko, Kyung Yuk; Lee, Chae A; Choi, Jae Chon; Kim, Meehye

2014-01-01

To date there have been no reports of methods to determine Tinopal CBS-X. We developed a rapid and simple method to determine the Tinopal CBS-X content in rice noodles and rice papers using HPLC equipped with fluorescence detection. Heating the rice noodles and rice papers to 80°C after adding 75% methanol solution induced the release of Tinopal CBS-X from processed rice products. Tinopal CBS-X was separated using an isocratic mobile phase comprising 50% acetonitrile/water containing 0.4% tetrabutyl ammonium hydrogen sulphate at pH 8.0. The samples suspected to be positive by HPLC analysis were then confirmed by LC-MS/MS analysis. This study also investigated the Tinopal CBS-X content of three rice noodle products and two rice papers. The limits of quantification for rice papers and rice noodles were 1.58 and 1.51 µg kg(-1), respectively, and their correlation curves showed good linearity with r(2) ≥ 0.9997 and ≥ 0.9998, respectively. Moreover, rice papers had recoveries of 70.3-83.3% with precision ranging from 5.0% to 7.9%, whereas rice noodles had slightly lower recoveries of 63.4-78.7% and precisions of 8.5-11.5%. Only one rice noodle product contained Tinopal CBS-X, at around 2.1 mg kg(-1), whereas it was not detected in four other samples. Consequently, Tinopal CBS-X from rice noodles and rice papers can be successfully detected using the developed pre-treatment and ion-pairing HPLC system coupled with fluorescence detection.
Anomalous enthalpy relaxation in vitreous silica

DEFF Research Database (Denmark)

Yue, Yuanzheng

2015-01-01

scans. It is known that the liquid fragility (i.e., the speed of the viscous slow-down of a supercooled liquid at its Tg during cooling) has impact on enthalpy relaxation in glass. Here, we find that vitreous silica (as a strong system) exhibits striking anomalies in both glass transition and enthalpy...... relaxation compared to fragile oxide systems. The anomalous enthalpy relaxation of vitreous silica is discovered by performing the hyperquenching-annealing-calorimetry experiments. We argue that the strong systems like vitreous silica and vitreous Germania relax in a structurally cooperative manner, whereas...... the fragile ones do in a structurally independent fashion. We discuss the origin of the anomalous enthalpy relaxation in the HQ vitreous silica....
Medicinal and nutritional importance of rice bran

International Nuclear Information System (INIS)

Ahmad, R.; Salim, M.; Rauf, R.; Baloach, M.K.

2005-01-01

Rice-bran is produced from the outer layer of brown rice and is stabilized through steam-heating. The rice-bran and its products are safe for human and animal consumption. The microbiological safety and rigorous quality-control practices merits its use as nutritional and dietary supplement for overall health-maintenance and as a part of a healthy diet and life-style, as it contributes to the reduction of certain diseases and health-related conditions. Stabilized rice-barn contain 15% of high nutritional- value protein, 20% of high-quality fat with Omega-3 and Omega-6 fatty acids, and nutritional dietary fiber. In addition to several phytonutrients, rice-bran contains vitamins and minerals, while over 100 potent antioxidants have been identified to date. Several scientific papers have reported the analysis and bioavailibility of rice-bran nutrients. Various chemical studies demonstrated the biological effects of the nutrients found in rice-bran. So far, more than 250 scientific publications are available on rice-bran, establishing the striking medicinal properties of rice-bran products. The oil-fraction of rice-bran has concentrated all tire fat-soluble phytonutrient in it, making itself an excellent health-promoting edible oil, as well as message oil The fiber-fraction of rice-bran has a profound effect on the gastrointestinal health, and improves bowel function. Rice-bran fiber along with phytonutrients was found to reduce cholesterol and lipid levels and maintain cardiovascular function. It has beneficial effect on tire kidney and urinary tract health and is helpful in weight-management and fiber replacement diets. (author)
Development of instant noodles from high-iron rice and iron-fortified rice flour

Directory of Open Access Journals (Sweden)

Suparat Reungmaneepaitoon

2008-08-01

Full Text Available Instant high-iron noodles, prepared from wheat flour and high iron brown rice flour, were developed. Three varieties of rice flour, Suphan Buri 90 (SB, Homnin 313 (HW and Homnin 1000 (HP, containing amylose content of 30.40, 19.10 and 15.74% (w/w and iron content of 1.24, 2.04 and 2.22 (mg/100 g respectively, were used to replace wheat flour for instant fried noodle production. To determine the physicochemical properties and acceptability of instant fried noodles,different percentages (30, 40, 50% (w/w of each rice flour sample were used. The instant fried noodles were fortified with ferrous sulphate at levels of 0, 32, 64% iron of RDI per serving. Increasing amount of iron content in the mixtures decreased the L* value, b* value and increased a* value for the color of the instant fried noodle with brown rice flour. The texture characteristic of the noodles with 30, 40, 50% replacement with each variety of brown rice flour were significantly different from those of wheat noodle. Tensile force of the noodles decreased from 11.57±1.30 g to 6.38±1.45 g (SB, 8.36±0.96 g to 5.71±0.57 g (HP and 10.09±1.20 g to 5.46±1.31 g (HW as the rice flour content increased from 30 to 50%. The sensoryacceptability of the noodles made from each variety of 30% brown rice flour fortified with 32% iron of RDI had higher preference scores for elasticity, firmness, color and overall acceptability, than those with 64% iron of RDI. Instant fried noodles with HW and HP brown rice flour were subjected to consumer test using 100 rural primary school children. The frequency percent of the acceptability scores of the noodle with HP and HW were 88 and 84% respectively. Shelf life studyrevealed that the developed products were still acceptable up to 4 months. These products were claimed to be high iron noodle.
The land use potential of flood-prone rice fields using floating rice system in Bojonegoro regency in East Java

Science.gov (United States)

Irianto, H.; Mujiyo; Riptanti, E. W.; Qonita, A.

2018-03-01

Bojonegoro regency occupies the largest flood-prone rice fields of about 14,198 hectares, in East Java province. Floods commonly occur due to Bengawan Solo river over-burst, particularly in rainy season. The fields are potential for cultivating rice, but floods lasting for months causing these areas to be unproductive. The objective of this article is to examine the potential land use of flood prone rice fields in Bojonegoro regency using floating rice system as an effort to maintain productivity in rainy season. The method of this study is referential study about the rice production using floating cultivation system in other regions, which are later compared with the physical condition of the fields in Bojonegoro. The results of analysis show that rice cultivation using floating system can maintain rice production in flood prone areas during rainy season. The potential production of rice is 5-6 tons/ha. However, technical problems for cultivating rice cannot be ignored since farmers are not familiar with cultivating flooded fields. This article also explains alternatives of floating rice cultivation technique, which can be implemented effectively and efficiently. Pioneer work of developing floating rice in Bojonegoro that has been done by the Team of Faculty of Agriculture of UNS, Surakarta, is expected to serve as a medium for accelerating the adoption of cultivation technology innovation to farmers.
Assessment of suitability of selected rice varieties for production of expanded rice

Directory of Open Access Journals (Sweden)

Vijayalaxmi Kamaraddi

2015-12-01

Full Text Available Expanded rice, prepared from pre-gelatinized milled rice by sand roasting method, is a popular snack food of India. Five high-yielding rice varieties of Hill zone of Karnataka state, viz., IET-13901, KHP-2, KHP-5, KHP-10, and Intan were screened for puffing quality based on their physicochemical, functional, nutritional and organoleptic parameters with Rajamudi as local check. The effect of varietal differences on expansion/puffing quality parameters, in vitro digestibility of starch and protein as well as bioaccessibility of iron, zinc, and calcium were determined. Results indicated a strong positive correlation between amylose content and expansion ratio and a negative correlation between protein and amylose content, length expansion ratio and volume expansion ratio. Expansion characteristics showed that the varieties suitable for production of puffed rice were KHP-2, IET-13901 and Intan. Nutritional analysis showed following ranges of nutrient content in expanded rice: protein, 6.22–8.17%; fat, 0.06–0.14%; and as mg/100 g calcium, 20.5–23.5; iron, 2.01–2.72; zinc, 1.22–1.82; thiamine, 0.315–0.470; riboflavin, 0.051–0.069; and niacin, 3.18–4.68. Nearly 80.3–80.8% starch and 67.6–83.2% protein was digestible. Among all varieties, KHP-2 had lowest amount of rapidly digestible starch (61.4%. Mineral bioaccessibility ranged from 42.7 to 52.1%. Sensory analysis indicated that Intan and KHP-2 were superior and suited for production of expanded rice.
Rice (Oryza) hemoglobins

Science.gov (United States)

Hemoglobins (Hbs) corresponding to non-symbiotic (nsHb) and truncated (tHb) Hbs have been identified in rice (Oryza). This review discusses the major findings from the current studies on rice Hbs. At the molecular level, a family of the nshb genes, consisting of hb1, hb2, hb3, hb4 and hb5, and a sin...
Aerobic rice mechanization: techniques for crop establishment

Science.gov (United States)

Khusairy, K. M.; Ayob, H.; Chan, C. S.; Fauzi, M. I. Mohamed; Mohamad Fakhrul, Z. O.; Shahril Shah, G. S. M.; Azlan, O.; Rasad, M. A.; Hashim, A. M.; Arshad, Z.; E, E. Ibrahim; Saifulizan, M. N.

2015-12-01

Rice being the staple food crops, hundreds of land races in it makes the diversity of rice crops. Aerobic rice production was introduced which requires much less water input to safeguard and sustain the rice production and conserve water due to decreasing water resources, climatic changes and competition from urban and industrial users. Mechanization system plays an important role for the success of aerobic rice cultivation. All farming activities for aerobic rice production are run on aerobic soil conditions. Row seeder mechanization system is developed to replace conventional seeding technique on the aerobic rice field. It is targeted for small and the large scale aerobic rice farmers. The aero - seeder machine is used for the small scale aerobic rice field, while the accord - seeder is used for the large scale aerobic rice field. The use of this mechanization machine can eliminate the tedious and inaccurate seeding operations reduce labour costs and increases work rate. The machine is easy to operate and it can increase crop establishment rate. It reduce missing hill, increasing planting and crop with high yield can be produce. This machine is designed for low costs maintenance and it is easy to dismantle and assemble during maintenance and it is safe to be used.
Practical Hydrogen Loading of Air Silica Fibres

DEFF Research Database (Denmark)

Sørensen, Henrik Rokkjær; Jensen, Jesper Bevensee; Jensen, Jesper Bo Damm

2005-01-01

A method for hydrogen-loading air-silica optical fibres has been developed allowing out-diffusion times comparable to standard step-index fibres. Examples of the first grating written in Ge-doped air-silica fibres using a 266nm UV-laser are shown.......A method for hydrogen-loading air-silica optical fibres has been developed allowing out-diffusion times comparable to standard step-index fibres. Examples of the first grating written in Ge-doped air-silica fibres using a 266nm UV-laser are shown....
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)
Characterization of materials formed by rice husk for construction

International Nuclear Information System (INIS)

Portillo-Rodríguez, A M

2013-01-01

This review article delves into the use of agro-industrial wastes, which in construction field provides alternatives for environmental problems with the use of them. This fact enables development and lower costs for new options in the brick, cluster, mortar and concrete industry, what represents benefits for environment, housing and generally everything related to construction, looking for sustainability. For that reason a literature review is made to support the theme focusing on the use of rice husk in its natural, ground or ash state for manufacturing elements with clay masonry, precast and optimization of concrete and mortars. The technique used is based on scientific articles and researches found in reliable databases that were analyzed and integrated into a synthesized structure, which summarized the objectives, analysis processes, the physical and mechanical properties and finally the results. The conclusions are focused on potentiality of elements production in the construction development based on the high effectiveness like thermal insulation, low density and various benefits offered by high silica content pozzolanic properties, etc
Characterization of materials formed by rice husk for construction

Science.gov (United States)

Portillo-Rodríguez, A. M.

2013-11-01

This review article delves into the use of agro-industrial wastes, which in construction field provides alternatives for environmental problems with the use of them. This fact enables development and lower costs for new options in the brick, cluster, mortar and concrete industry, what represents benefits for environment, housing and generally everything related to construction, looking for sustainability. For that reason a literature review is made to support the theme focusing on the use of rice husk in its natural, ground or ash state for manufacturing elements with clay masonry, precast and optimization of concrete and mortars. The technique used is based on scientific articles and researches found in reliable databases that were analyzed and integrated into a synthesized structure, which summarized the objectives, analysis processes, the physical and mechanical properties and finally the results. The conclusions are focused on potentiality of elements production in the construction development based on the high effectiveness like thermal insulation, low density and various benefits offered by high silica content pozzolanic properties, etc.
Effect of support on hydro-metathesis of propene: A comparative study of W(CH 3 ) 6 anchored to silica vs. silica-alumina

KAUST Repository

Tretiakov, Mykyta; Samantaray, Manoja; Saidi, Aya; Basset, Jean-Marie

2018-01-01

Hydro-metathesis of propene was carried out by using well-defined W(CH3)6 supported on silica and silica-alumina. It was observed that W(CH3)6 supported silica-alumina catalyst is much better (TON 4577) than the silica supported catalyst (TON 2104

Understanding the evolution of rice technology in China - from traditional agriculture to GM rice today.

Science.gov (United States)

Shen, Xiaobai

2010-01-01

This paper provides an historical survey of the evolution of rice technology in China, from the traditional farming system to genetically modified rice today. Using sociotechnological analytical framework, it analyses rice technology as a socio-technical ensemble - a complex interaction of material and social elements, and discusses the specificity of technology development and its socio-technical outcomes. It points to two imperatives in rice variety development: wholesale transporting agricultural technology and social mechanism to developing countries are likely lead to negative consequences; indigenous innovation including deploying GM technology for seed varietal development and capturing/cultivating local knowledge will provide better solutions.
Altering the concentration of silica tunes the functional properties of collagen-silica composite scaffolds to suit various clinical requirements.

Science.gov (United States)

Perumal, Sathiamurthi; Ramadass, Satiesh Kumar; Gopinath, Arun; Madhan, Balaraman; Shanmugam, Ganesh; Rajadas, Jayakumar; Mandal, Asit Baran

2015-12-01

The success of a tissue engineering scaffold depends on a fine balance being achieved between the physicochemical and biological properties. This study attempts to understand the influence of silica concentration on the functional properties of collagen-silica (CS) composite scaffolds for soft tissue engineering applications. Increasing the ratio of silica to collagen (0.25, 0.5, 0.75, 1.0, 1.25, 1.5 and 2.0 w/w) gave a marked advantage in terms of improving the water uptake and compressive modulus of the CS scaffolds, while also enhancing the biological stability and the turnover time. With increase in silica concentration the water uptake and compressive modulus increased concurrently, whereas it was not so for surface porous architecture and biocompatibility which are crucial for cell adhesion and infiltration. Silica:collagen ratio of ≤1 exhibits favourable surface biocompatibility, and any further increase in silica concentration has a detrimental effect. Copyright © 2015 Elsevier Ltd. All rights reserved.
Silica-Coated Liposomes for Insulin Delivery

OpenAIRE

Neelam Dwivedi; M. A. Arunagirinathan; Somesh Sharma; Jayesh Bellare

2010-01-01

Liposomes coated with silica were explored as protein delivery vehicles for their enhanced stability and improved encapsulation efficiency. Insulin was encapsulated within the fluidic phosphatidylcholine lipid vesicles by thin film hydration at pH 2.5, and layer of silica was formed above lipid bilayer by acid catalysis. The presence of silica coating and encapsulated insulin was identified using confocal and electron microscopy. The native state of insulin present in the formulation was evid...
Brazilian Consensus on Photoprotection

Science.gov (United States)

Schalka, Sérgio; Steiner, Denise; Ravelli, Flávia Naranjo; Steiner, Tatiana; Terena, Aripuanã Cobério; Marçon, Carolina Reato; Ayres, Eloisa Leis; Addor, Flávia Alvim Sant'anna; Miot, Helio Amante; Ponzio, Humberto; Duarte, Ida; Neffá, Jane; da Cunha, José Antônio Jabur; Boza, Juliana Catucci; Samorano, Luciana de Paula; Corrêa, Marcelo de Paula; Maia, Marcus; Nasser, Nilton; Leite, Olga Maria Rodrigues Ribeiro; Lopes, Otávio Sergio; Oliveira, Pedro Dantas; Meyer, Renata Leal Bregunci; Cestari, Tânia; dos Reis, Vitor Manoel Silva; Rego, Vitória Regina Pedreira de Almeida

2014-01-01

Brazil is a country of continental dimensions with a large heterogeneity of climates and massive mixing of the population. Almost the entire national territory is located between the Equator and the Tropic of Capricorn, and the Earth axial tilt to the south certainly makes Brazil one of the countries of the world with greater extent of land in proximity to the sun. The Brazilian coastline, where most of its population lives, is more than 8,500 km long. Due to geographic characteristics and cultural trends, Brazilians are among the peoples with the highest annual exposure to the sun. Epidemiological data show a continuing increase in the incidence of non-melanoma and melanoma skin cancers. Photoprotection can be understood as a set of measures aimed at reducing sun exposure and at preventing the development of acute and chronic actinic damage. Due to the peculiarities of Brazilian territory and culture, it would not be advisable to replicate the concepts of photoprotection from other developed countries, places with completely different climates and populations. Thus the Brazilian Society of Dermatology has developed the Brazilian Consensus on Photoprotection, the first official document on photoprotection developed in Brazil for Brazilians, with recommendations on matters involving photoprotection. PMID:25761256
Diazotrophic bacteria isolated from wild rice Oryza glumaepatula (Poaceae in the Brazilian Amazon

Directory of Open Access Journals (Sweden)

Paulo Ivan Fernandes Júnior

2013-06-01

Full Text Available The association of wild grasses with diazotrophic bacteria in Brazilian biomes is poorly understood. The isolation and characterization of bacteria associated with wild grasses can contribute to understand the diazotrophic ecology as well as to identify bacteria with biotechnological applications. In this study, we isolated and characterized diazotrophic bacterial isolates from Oryza glumaepatula collected in Cerrado and Forest areas of the Amazon in Roraima State, Brazil. Healthy O. glumepatula plants were collected at five sampling sites at Forest and seven at Cerrado, respectively. The plants were collected at the Cerrado areas in September 2008 while the Forest plants were collected in June/2008 and April/2009. The plants and the soil adhering to the roots were transferred to pots and grown for 35 days in greenhouse conditions. During the harvest, the shoots and the roots were crushed separately in a saline solution; the suspension was diluted serially and inoculated in Petri dishes containing Dyg’s medium. All distinct bacterial colonies were purified in the same medium. The diazotrophic capacity of each bacterium in microaerophilic conditions was assessed in semisolid BMGM medium. In addition, the pellicles forming bacterial isolates were also evaluated by PCR amplification for nifH gene. The diversity of nifH+ bacteria was analyzed by Box-PCR fingerprinting. For selected strains, the growth promoting capacity of O. sativa as a model plant was also evaluated. A total of 992 bacterial isolates were obtained. Fifty- one bacteria were able to form pellicles in the semisolid medium and 38 also positively amplified the 360bp nifH gene fragment. Among the 38 nifH+ isolates, 24 were obtained from the shoots, while 14 originated from the roots. The Box-PCR profiles showed that the bacterial isolates obtained in this study presented a low similarity with the reference strains belonging to the Herbaspirillum, Azospirillum and Burkholderia genus
Diazotrophic bacteria isolated from wild rice Oryza glumaepatula (Poaceae) in the Brazilian Amazon.

Science.gov (United States)

Júnior, Paulo Ivan Fernandes; Pereira, Gilmara Maria Duarte; Perin, Liamara; da Silva, Luana Mesquita; Baraúna, Alexandre Cardoso; Alvess, Francilene Muniz; Passos, Samuel Ribeiro; Zilli, Jerri Edson

2013-06-01

The association of wild grasses with diazotrophic bacteria in Brazilian biomes is poorly understood. The isolation and characterization of bacteria associated with wild grasses can contribute to understand the diazotrophic ecology as well as to identify bacteria with biotechnological applications. In this study, we isolated and characterized diazotrophic bacterial isolates from Oryza glumaepatula collected in Cerrado and Forest areas of the Amazon in Roraima State, Brazil. Healthy O. glumepatula plants were collected at five sampling sites at Forest and seven at Cerrado, respectively. The plants were collected at the Cerrado areas in September 2008 while the Forest plants were collected in June/2008 and April/2009. The plants and the soil adhering to the roots were transferred to pots and grown for 35 days in greenhouse conditions. During the harvest, the shoots and the roots were crushed separately in a saline solution; the suspension was diluted serially and inoculated in Petri dishes containing Dyg's medium. All distinct bacterial colonies were purified in the same medium. The diazotrophic capacity of each bacterium in microaerophilic conditions was assessed in semisolid BMGM medium. In addition, the pellicles forming bacterial isolates were also evaluated by PCR amplification for nifH gene. The diversity of nifH bacteria was analyzed by Box-PCR fingerprinting. For selected strains, the growth promoting capacity of O. sativa as a model plant was also evaluated. A total of 992 bacterial isolates were obtained. Fifty-one bacteria were able to form pellicles in the semisolid medium and 38 also positively amplified the 360 bp nifH gene fragment. Among the 38 nifH+ isolates, 24 were obtained from the shoots, while 14 originated from the roots. The Box-PCR profiles showed that the bacterial isolates obtained in this study presented a low similarity with the reference strains belonging to the Herbaspirillum, Azospirillum and Burkholderia genus. The growth
Elemental composition of Malawian rice.

Science.gov (United States)

Joy, Edward J M; Louise Ander, E; Broadley, Martin R; Young, Scott D; Chilimba, Allan D C; Hamilton, Elliott M; Watts, Michael J

2017-08-01

Widespread potential dietary deficiencies of calcium (Ca), iron (Fe), iodine (I), selenium (Se) and zinc (Zn) have been identified in Malawi. Several deficiencies are likely to be compounded by high phytic acid (PA) consumption. Rice (Oryza sativa) is commonly consumed in some Malawian populations, and its mineral micronutrient content is important for food security. The considerable irrigation requirements and flooded conditions of paddy soils can also introduce or mobilise potentially toxic elements including arsenic (As), cadmium (Cd) and lead (Pb). The aim of this study was to determine the mineral composition of rice sampled from farmers' fields and markets in Malawi. Rice was sampled from 18 extension planning areas across Malawi with 21 white (i.e. polished) and 33 brown samples collected. Elemental composition was determined by inductively coupled plasma-mass spectrometry (ICP-MS). Arsenic speciation was performed using high-performance liquid chromatography (HPLC)-ICP-MS. Concentration of PA was determined using a PA-total phosphorus assay. Median total concentrations (mg kg -1 , dry weight) of elements important for human nutrition in brown and white rice, respectively, were: Ca = 66.5 and 37.8; Cu = 3.65 and 2.49; Fe = 22.1 and 7.2; I = 0.006 and rice samples, respectively, median PA concentrations were 5438 and 1906 mg kg -1 , and median PA:Zn molar ratios were 29 and 13. Concentrations of potentially toxic elements (mg kg -1 , dry weight) in brown and white rice samples, respectively, were: As = 0.030 and 0.006; Cd ≤ 0.002 and 0.006; Pb = 0.008 and 0.008. Approximately 95 % of As was found to be inorganic As, where this could be quantified. Malawian rice, like the more widely consumed staple grain maize, contains inadequate Ca, I, Se or Zn to meet dietary requirements. Biofortification strategies could significantly increase Se and Zn concentrations and require further investigation. Concentrations of Fe in rice grain varied
Kinetics of silica-phase transitions

International Nuclear Information System (INIS)

Duffy, C.J.

1993-07-01

In addition to the stable silica polymorph quartz, several metastable silica phases are present in Yucca Mountain. The conversion of these phases to quartz is accompanied by volume reduction and a decrease in the aqueous silica activity, which may destabilize clinoptilolite and mordenite. The primary reaction sequence for the silica phases is from opal or glass to disordered opal-CT, followed by ordering of the opal-CT and finally by the crystallization of quartz. The ordering of opal-CT takes place in the solid state, whereas the conversion of opal-CT takes place through dissolution-reprecipitation involving the aqueous phase. It is proposed that the rate of conversion of opal-CT to quartz is controlled by diffusion of defects out of a disordered surface layer formed on the crystallizing quartz. The reaction rates are observed to be dependent on temperature, pressure, degree of supersaturation, and pH. Rate equations selected from the literature appear to be consistent with observations at Yucca Mountain
The Impact of Herbicide-Resistant Rice Technology on Phenotypic Diversity and Population Structure of United States Weedy Rice1[W][OPEN

Science.gov (United States)

Burgos, Nilda Roma; Singh, Vijay; Tseng, Te Ming; Black, Howard; Young, Nelson D.; Huang, Zhongyun; Hyma, Katie E.; Gealy, David R.; Caicedo, Ana L.

2014-01-01

The use of herbicide-resistant (HR) Clearfield rice (Oryza sativa) to control weedy rice has increased in the past 12 years to constitute about 60% of rice acreage in Arkansas, where most U.S. rice is grown. To assess the impact of HR cultivated rice on the herbicide resistance and population structure of weedy rice, weedy samples were collected from commercial fields with a history of Clearfield rice. Panicles from each weedy type were harvested and tested for resistance to imazethapyr. The majority of plants sampled had at least 20% resistant offspring. These resistant weeds were 97 to 199 cm tall and initiated flowering from 78 to 128 d, generally later than recorded for accessions collected prior to the widespread use of Clearfield rice (i.e. historical accessions). Whereas the majority (70%) of historical accessions had straw-colored hulls, only 30% of contemporary HR weedy rice had straw-colored hulls. Analysis of genotyping-by-sequencing data showed that HR weeds were not genetically structured according to hull color, whereas historical weedy rice was separated into straw-hull and black-hull populations. A significant portion of the local rice crop genome was introgressed into HR weedy rice, which was rare in historical weedy accessions. Admixture analyses showed that HR weeds tend to possess crop haplotypes in the portion of chromosome 2 containing the ACETOLACTATE SYNTHASE gene, which confers herbicide resistance to Clearfield rice. Thus, U.S. HR weedy rice is a distinct population relative to historical weedy rice and shows modifications in morphology and phenology that are relevant to weed management. PMID:25122473
Mercury in rice (Oryza sativa L.) and rice-paddy soils under long-term fertilizer and organic amendment.

Science.gov (United States)

Tang, Zhenya; Fan, Fangling; Wang, Xinyue; Shi, Xiaojun; Deng, Shiping; Wang, Dingyong

2018-04-15

High levels of mercury (Hg), especially methylmercury (MeHg), in rice is of concern due to its potential of entering food chain and the high toxicity to human. The level and form of Hg in rice could be influenced by fertilizers and other soil amendments. Studies were conducted to evaluate the effect of 24 years application of chemical fertilizers and organic amendments on total Hg (THg) and MeHg and their translocation in soil, plants, and rice grain. All treatments led to significantly higher concentrations of MeHg in grain than those from the untreated control. Of nine treatments tested, chemical fertilizers combining with returning rice straw (NPK1+S) led to highest MeHg concentration in grain and soil; while the nitrogen and potassium (NK) treatment led to significantly higher THg in grain. Concentrations of soil MeHg were significantly correlated with THg in soil (r = 0.59 *** ) and MeHg in grain (r = 0.48 *** ). Calcium superphosphate negatively affected plant bioavailability of soil Hg. MeHg concentration in rice was heavily influenced by soil Hg levels. Phosphorus fertilizer was a main source contributing to soil THg, while returning rice straw to the field contributed significantly to MeHg in soil and rice grain. As a result, caution should be exercised in soil treatment or when utilizing Hg-contaminated soils to produce rice for human consumption. Strategic management of rice straw and phosphorus fertilizer could be effective strategies of lowering soil Hg, which would ultimately lower MeHg in rice and the risk of Hg entering food chain. Copyright © 2017 Elsevier Inc. All rights reserved.
Realistic Simulation of Rice Plant

Directory of Open Access Journals (Sweden)

Wei-long DING

2011-09-01

Full Text Available The existing research results of virtual modeling of rice plant, however, is far from perfect compared to that of other crops due to its complex structure and growth process. Techniques to visually simulate the architecture of rice plant and its growth process are presented based on the analysis of the morphological characteristics at different stages. Firstly, the simulations of geometrical shape, the bending status and the structural distortion of rice leaves are conducted. Then, by using an improved model for bending deformation, the curved patterns of panicle axis and various types of panicle branches are generated, and the spatial shape of rice panicle is therefore created. Parametric L-system is employed to generate its topological structures, and finite-state automaton is adopted to describe the development of geometrical structures. Finally, the computer visualization of three-dimensional morphologies of rice plant at both organ and individual levels is achieved. The experimental results showed that the proposed methods of modeling the three-dimensional shapes of organs and simulating the growth of rice plant are feasible and effective, and the generated three-dimensional images are realistic.
Transgenic rice plants expressing synthetic cry2AX1 gene exhibits resistance to rice leaffolder (Cnaphalocrosis medinalis).

Science.gov (United States)

Manikandan, R; Balakrishnan, N; Sudhakar, D; Udayasuriyan, V

2016-06-01

Bacillus thuringiensis is a major source of insecticidal genes imparting insect resistance in transgenic plants. Level of expression of transgenes in transgenic plants is important to achieve desirable level of resistance against target insects. In order to achieve desirable level of expression, rice chloroplast transit peptide sequence was fused with synthetic cry2AX1 gene to target its protein in chloroplasts. Sixteen PCR positive lines of rice were generated by Agrobacterium mediated transformation using immature embryos. Southern blot hybridization analysis of T 0 transgenic plants confirmed the integration of cry2AX1 gene in two to five locations of rice genome and ELISA demonstrated its expression. Concentration of Cry2AX1 in transgenic rice events ranged 5.0-120 ng/g of fresh leaf tissue. Insect bioassay of T 0 transgenic rice plants against neonate larvae of rice leaffolder showed larval mortality ranging between 20 and 80 % in comparison to control plant. Stable inheritance and expression of cry2AX1 gene was demonstrated in T 1 progenies through Southern and ELISA. In T 1 progenies, the highest concentration of Cry2AX1 and mortality of rice leaffolder larvae were recorded as 150 ng/g of fresh leaf tissue and 80 %, respectively. The Cry2AX1 expression even at a very low concentration (120-150 ng/g) in transgenic rice plants was found effective against rice leaffolder larvae.
Late-maturing cooking rice Sensyuraku has excellent properties, equivalent to sake rice, for high-quality sake brewing.

Science.gov (United States)

Anzawa, Yoshihiko; Satoh, Kenji; Satoh, Yuko; Ohno, Satomi; Watanabe, Tsutomu; Katsumata, Kazuaki; Kume, Kazunori; Watanabe, Ken-Ichi; Mizunuma, Masaki; Hirata, Dai

2014-01-01

Low protein content and sufficient grain rigidity are desired properties for the rice used in high-quality sake brewing such as Daiginjo-shu (polishing ratio of the rice, less than 50%). Two kinds of rice, sake rice (SR) and cooking rice (CR), have been used for sake brewing. Compared with those of SR, analyses of CR for high-quality sake brewing using highly polished rice have been limited. Here we described the original screening of late-maturing CR Sensyuraku (SEN) as rice with low protein content and characterization of its properties for high-quality sake brewing. The protein content of SEN was lower than those of SR Gohyakumangoku (GOM) and CR Yukinosei (YUK), and its grain rigidity was higher than that of GOM. The excellent properties of SEN with respect to both water-adsorption and enzyme digestibility were confirmed using a Rapid Visco Analyzer (RVA). Further, we confirmed a clear taste of sake produced from SEN by sensory evaluation. Thus, SEN has excellent properties, equivalent to those of SR, for high-quality sake brewing.
Rates of nitrogen from nitric and ammoniacal sources required by upland rice genotypes originating from Brazil and Colombia

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Hector Augusto Sandoval Contreras

2016-06-01

Full Text Available The aim of this study was to evaluate the initial growth, nitrogen (N uptake, and agronomic efficiency after the use of N fertilizers in upland rice cultivation. The experiment was conducted in a greenhouse by using pots filled with surface-layer (0 to 20 cm soil collected from the municipality of Jaguapitã, Paraná. The experimental design was completely randomized with 4 replications. A factorial scheme of 5 × 2 was used, in which the factors were 5 N rates (0, 25, 50, 75, and 100 kg ha-1 N and 2 cultivars of rice (Fedearroz Lagunas [Colombian] and IAPAR- 9 [Brazilian]. The N sources tested were ammonium sulfate (Experiment I and calcium nitrate (Experiment II. The following variables were evaluated: number of tillers per pot (NTP, dry mass of the shoots (DMS, N content in the dry mass (NCDM, and agronomic efficiency of N fertilizer (AEN. The data obtained in the experiments were evaluated using analysis of variance, and mean values were compared using Tukey’s test at 5% significance for rice cultivar effects or adjusted to polynomial regression equations for N rates. Use of calcium nitrate yielded higher values of NTP, NCDM, and AEN. The cultivar Lagunas showed higher NTP, while IAPAR-9 showed higher DMS. An increase in N rates, for both sources, resulted in the increase of NTP, DMS, and NCDM; however, AEN was decreased.
Tungsten (W) bioavailability in paddy rice soils and its accumulation in rice (Oryza sativa).

Science.gov (United States)

James, Blessing; Zhang, Weili; Sun, Pei; Wu, Mingyan; Li, Hong Hong; Khaliq, Muhammad Athar; Jayasuriya, Pathmamali; James, Swithin; Wang, Guo

2017-12-01

The aim of this study was to investigate the accumulation characteristics of tungsten (W) by different indica rice cultivars from the soil and to assess the potential risks to human health via dietary intake of W in rice consumption. A total of 153 rice (ear) samples of 15 cultivars and the corresponding surface soil samples were collected from 7 cities in Fujian Province of southeastern China. The available soil W were extracted using H 2 C 2 O 4 ·2H 2 O-(NH 4 ) 2 C 2 O 4 ·H 2 O at pH 3.3). Results showed that the total soil W ranged from 2.03 mg kg -1 to 15.34 mg kg -1 and available soil W ranged from 0.03 mg kg -1 to 1.61 mg kg -1 . The W concentration in brown rice varied from 7 μg kg -1 to 283 μg kg -1 and was significantly correlated with the available soil W. The highest mean TF avail (transfer factor based on available soil W) was 0.91 for Te-you 627 (hybrid, indica rice), whereas the lowest was 0.08 for Yi-you 673 (hybrid, indica rice). The TF avail decreased with the increase in available soil W, clay content, and cation exchange capacity. The consumption of the brown rice produced from the investigated areas in some cultivars by the present study may cause risks to human health.
Health hazards due to the inhalation of amorphous silica

Energy Technology Data Exchange (ETDEWEB)

Merget, R.; Bruening, T. [Research Institute for Occupational Medicine (BGFA), Bochum (Germany); Bauer, T. [Bergmannsheil, University Hospital, Department of Internal Medicine, Division of Pneumonology, Allergology and Sleep Medicine, Bochum (Germany); Kuepper, H.U.; Breitstadt, R. [Degussa-Huels Corp., Wesseling (Germany); Philippou, S. [Department of Pathology, Augusta Krankenanstalten, Bochum (Germany); Bauer, H.D. [Research Institute for Hazardous Substances (IGF), Bochum (Germany)

2002-01-01

Occupational exposure to crystalline silica dust is associated with an increased risk for pulmonary diseases such as silicosis, tuberculosis, chronic bronchitis, chronic obstructive pulmonary disease (COPD) and lung cancer. This review summarizes the current knowledge about the health effects of amorphous (non-crystalline) forms of silica. The major problem in the assessment of health effects of amorphous silica is its contamination with crystalline silica. This applies particularly to well-documented pneumoconiosis among diatomaceous earth workers. Intentionally manufactured synthetic amorphous silicas are without contamination of crystalline silica. These synthetic forms may be classified as (1) wet process silica, (2) pyrogenic (''thermal'' or ''fumed'') silica, and (3) chemically or physically modified silica. According to the different physico-chemical properties, the major classes of synthetic amorphous silica are used in a variety of products, e.g. as fillers in the rubber industry, in tyre compounds, as free-flow and anti-caking agents in powder materials, and as liquid carriers, particularly in the manufacture of animal feed and agrochemicals; other uses are found in toothpaste additives, paints, silicon rubber, insulation material, liquid systems in coatings, adhesives, printing inks, plastisol car undercoats, and cosmetics. Animal inhalation studies with intentionally manufactured synthetic amorphous silica showed at least partially reversible inflammation, granuloma formation and emphysema, but no progressive fibrosis of the lungs. Epidemiological studies do not support the hypothesis that amorphous silicas have any relevant potential to induce fibrosis in workers with high occupational exposure to these substances, although one study disclosed four cases with silicosis among subjects exposed to apparently non-contaminated amorphous silica. Since the data have been limited, a risk of chronic bronchitis, COPD or
Health hazards due to the inhalation of amorphous silica

International Nuclear Information System (INIS)

Merget, R.; Bruening, T.; Bauer, T.; Kuepper, H.U.; Breitstadt, R.; Philippou, S.; Bauer, H.D.

2002-01-01

Occupational exposure to crystalline silica dust is associated with an increased risk for pulmonary diseases such as silicosis, tuberculosis, chronic bronchitis, chronic obstructive pulmonary disease (COPD) and lung cancer. This review summarizes the current knowledge about the health effects of amorphous (non-crystalline) forms of silica. The major problem in the assessment of health effects of amorphous silica is its contamination with crystalline silica. This applies particularly to well-documented pneumoconiosis among diatomaceous earth workers. Intentionally manufactured synthetic amorphous silicas are without contamination of crystalline silica. These synthetic forms may be classified as (1) wet process silica, (2) pyrogenic (''thermal'' or ''fumed'') silica, and (3) chemically or physically modified silica. According to the different physico-chemical properties, the major classes of synthetic amorphous silica are used in a variety of products, e.g. as fillers in the rubber industry, in tyre compounds, as free-flow and anti-caking agents in powder materials, and as liquid carriers, particularly in the manufacture of animal feed and agrochemicals; other uses are found in toothpaste additives, paints, silicon rubber, insulation material, liquid systems in coatings, adhesives, printing inks, plastisol car undercoats, and cosmetics. Animal inhalation studies with intentionally manufactured synthetic amorphous silica showed at least partially reversible inflammation, granuloma formation and emphysema, but no progressive fibrosis of the lungs. Epidemiological studies do not support the hypothesis that amorphous silicas have any relevant potential to induce fibrosis in workers with high occupational exposure to these substances, although one study disclosed four cases with silicosis among subjects exposed to apparently non-contaminated amorphous silica. Since the data have been limited, a risk of chronic bronchitis, COPD or emphysema cannot be excluded. There is no
Increasing rice plant growth by Trichoderma sp.

Science.gov (United States)

Doni, Febri; Isahak, Anizan; Zain, Che Radziah Che Mohd; Sulaiman, Norela; Fathurahman, F.; Zain, Wan Nur Syazana Wan Mohd.; Kadhimi, Ahsan A.; Alhasnawi, Arshad Naji; Anhar, Azwir; Yusoff, Wan Mohtar Wan

2016-11-01

Trichoderma sp. is a plant growth promoting fungi in many crops. Initial observation on the ability to enhance rice germination and vigor have been reported. In this study, the effectiveness of a local isolate Trichoderma asprellum SL2 to enhance rice seedling growth was assessed experimentally under greenhouse condition using a completely randomized design. Results showed that inoculation of rice plants with Trichoderma asprellum SL2 significantly increase rice plants height, root length, wet weight, leaf number and biomass compared to untreated rice plants (control). The result of this study can serve as a reference for further work on the application of beneficial microorganisms to enhance rice production.
The rice growth image files - The Rice Growth Monitoring for The Phenotypic Functional Analysis | LSDB Archive [Life Science Database Archive metadata

Lifescience Database Archive (English)

Full Text Available List Contact us The Rice Growth Monitoring for The Phenotypic Functional Analysis The rice growth image file...s Data detail Data name The rice growth image files DOI 10.18908/lsdba.nbdc00945-004 Description of data contents The rice growth ima...ge files categorized based on file size. Data file File name: image files (director...y) File URL: ftp://ftp.biosciencedbc.jp/archive/agritogo-rice-phenome/LATEST/image...ite Policy | Contact Us The rice growth image files - The Rice Growth Monitoring for The Phenotypic Functional Analysis | LSDB Archive ...
[Extruded rice flour as a gluten substitute in the poduction of rice bread].

Science.gov (United States)

Clerici, Maria Teresa Pedrosa Silva; El-Dash, Ahmed A

2006-09-01

Research regarding the production of gluten-free bread (GFB) is very important nutritionally, technically and economically speaking, both to celiac patients and to developing countries who import wheat. The main technological problem in the production of GFB is obtaining a gluten substitute that is both inexpensive and capable of retaining gas during bread fermentation and baking. The use of gelatinized starch as an alternative for gluten seems promising. In this project, rice bread was made using pregelatinized extruded rice flour as a gluten substitute. Pre-gelatinized rice flours (PRF) were manufactured in a single screw Brabender extruder, varying extrusion temperature (108-192 degrees C) and the moisture of the raw material (19.2 - 24.8%), and were used in a proportion of 10 g for every 100 g of raw rice flour, in the production of gluten-free bread. Results showed that rice flour extruded at a high temperature (180 degrees) and low moisture content (20%), rendered bread with the best technological characteristics, presenting crust and crumb color similar to those of conventional wheat bread, although with volume and texture not as satisfactory in the same comparison.

Fermented Brown Rice Flour as Functional Food Ingredient.

Science.gov (United States)

Ilowefah, Muna; Chinma, Chiemela; Bakar, Jamilah; Ghazali, Hasanah M; Muhammad, Kharidah; Makeri, Mohammad

2014-02-12

As fermentation could reduce the negative effects of bran on final cereal products, the utilization of whole-cereal flour is recommended, such as brown rice flour as a functional food ingredient. Therefore, this study aimed to investigate the effect of fermented brown rice flour on white rice flour, white rice batter and its steamed bread qualities. Brown rice batter was fermented using commercial baker's yeast (Eagle brand) according to the optimum conditions for moderate acidity (pH 5.5) to obtain fermented brown rice flour (FBRF). The FBRF was added to white rice flour at 0%, 10%, 20%, 30%, 40% and 50% levels to prepare steamed rice bread. Based on the sensory evaluation test, steamed rice bread containing 40% FBRF had the highest overall acceptability score. Thus, pasting properties of the composite rice flour, rheological properties of its batter, volume and texture properties of its steamed bread were determined. The results showed that peak viscosity of the rice flour containing 40% FBRF was significantly increased, whereas its breakdown, final viscosity and setback significantly decreased. Viscous, elastic and complex moduli of the batter having 40% FBRF were also significantly reduced. However, volume, specific volume, chewiness, resilience and cohesiveness of its steamed bread were significantly increased, while hardness and springiness significantly reduced in comparison to the control. These results established the effectiveness of yeast fermentation in reducing the detrimental effects of bran on the sensory properties of steamed white rice bread and encourage the usage of brown rice flour to enhance the quality of rice products.
Lead enrichment in different genotypes of rice grains.

Science.gov (United States)

Chen, Gang; Sun, Guo-rong; Liu, Ai-ping; Zhou, Wei-dong

2008-03-01

Using environmental scanning electron microscopy and X-ray electron probe microanalysis, the lead content was studied in inner and outer surface of rice glume, surface of caryopsis, center of caryopsis, near aleuronic layer and aleuronic layer in 21 genotypes of rice grains. The results showed that the lead content in different part of 21 genotypes of rice grains changed as inner surface of rice glume > aleuronic layer > near aleuronic layer > surface of caryopsis > outer surface of rice glume > center of caryopsis. There were genetic differences in lead enrichment in different genotypes of rice grains, which reflected as the differences of lead content in the same part and different part of rice grains. In different genotypes of rice grains, there were significant non-linear correlations between lead content in the inner surface of rice glume, center of caryopsis, aleuronic layer and that in the other parts of rice grain. The results also indicated that the lead enrichment in the center of caryopsis regulated by glume and aleuronic layer. In addition, in different genotypes of rice grains, there were differences in regulation of lead enrichment among different parts, which changed non-linearly.
21 CFR 573.160 - Ammoniated rice hulls.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ammoniated rice hulls. 573.160 Section 573.160... Additive Listing § 573.160 Ammoniated rice hulls. The food additive ammoniated rice hulls may be safely... obtained by the treatment of ground rice hulls with monocalcium phosphate and anhydrous ammonia at a...
Effect of Temperature on Chinese Rice Wine Brewing with High Concentration Presteamed Whole Sticky Rice

Science.gov (United States)

Zhang, Hong-Tao; Xiong, Weili; Hu, Jianhua; Xu, Baoguo; Lin, Chi-Chung; Xu, Ling; Jiang, Lihua

2014-01-01

Production of high quality Chinese rice wine largely depends on fermentation temperature. However, there is no report on the ethanol, sugars, and acids kinetics in the fermentation mash of Chinese rice wine treated at various temperatures. The effects of fermentation temperatures on Chinese rice wine quality were investigated. The compositions and concentrations of ethanol, sugars, glycerol, and organic acids in the mash of Chinese rice wine samples were determined by HPLC method. The highest ethanol concentration and the highest glycerol concentration both were attained at the fermentation mash treated at 23°C. The highest peak value of maltose (90 g/L) was obtained at 18°C. Lactic acid and acetic acid both achieved maximum values at 33°C. The experimental results indicated that temperature contributed significantly to the ethanol production, acid flavor contents, and sugar contents in the fermentation broth of the Chinese rice wines. PMID:24672788
Grassy Silica Nanoribbons and Strong Blue Luminescence

Science.gov (United States)

Wang, Shengping; Xie, Shuang; Huang, Guowei; Guo, Hongxuan; Cho, Yujin; Chen, Jun; Fujita, Daisuke; Xu, Mingsheng

2016-09-01

Silicon dioxide (SiO2) is one of the key materials in many modern technological applications such as in metal oxide semiconductor transistors, photovoltaic solar cells, pollution removal, and biomedicine. We report the accidental discovery of free-standing grassy silica nanoribbons directly grown on SiO2/Si platform which is commonly used for field-effect transistors fabrication without other precursor. We investigate the formation mechanism of this novel silica nanostructure that has not been previously documented. The silica nanoribbons are flexible and can be manipulated by electron-beam. The silica nanoribbons exhibit strong blue emission at about 467 nm, together with UV and red emissions as investigated by cathodoluminescence technique. The origins of the luminescence are attributed to various defects in the silica nanoribbons; and the intensity change of the blue emission and green emission at about 550 nm is discussed in the frame of the defect density. Our study may lead to rational design of the new silica-based materials for a wide range of applications.
Characterization of silica particles prepared via urease-catalyzed urea hydrolysis and activity of urease in sol–gel silica matrix

International Nuclear Information System (INIS)

Kato, Katsuya; Nishida, Masakazu; Ito, Kimiyasu; Tomita, Masahiro

2012-01-01

Highlights: ► Silica precipitation occurred via urease-catalytic reactions. ► Higher urease activity for silica synthesis enables mesostructure of silica–urease composites. ► Urease encapsulating in silica matrix retained high activity. - Abstract: Urease templated precipitation of silica synthesized by sol–gel chemistry produces a composite material allowing high urease activity. This study investigates the structural properties of the composite material that allow for the retention of the urease hydrolysis activity. Scanning (SEM) and transmission (TEM) electron microscopy reveal that the composite has a mesoporous structure composed of closely packed spherical structures ∼20–50 nm in diameter. Brunauer–Emmett–Teller (BET) analysis revealed that the surface area and pore volume of the composite prepared under the conditions of 50 mM urea and 25 °C is relatively high (324 m 2 /g and 1.0 cm 3 /g). These values are equivalent to those of usual mesoporous silica materials synthesized from the self-assembly of triblock copolymers as organic templates. In addition, after encapsulating in a sol–gel silica matrix, urease retained high activity (∼90% of the activity compared with native urease). Our results suggest a new method for synthesizing mesoporous silica materials with highly tunable pore sizes and shapes under mild conditions.
New market opportunities for rice grains

Science.gov (United States)

Breeding efforts for rice have been focusing on increasing yield and improving quality (milling yield and grain quality), while maintaining cooked rice sensory properties to meet consumer preferences. These breeding targets will no doubt continue as the main foci for the rice industry. However, the ...
Winter climate change and fine root biogenic silica in sugar maple trees (Acer saccharum): Implications for silica in the Anthropocene

Science.gov (United States)

Maguire, Timothy J.; Templer, Pamela H.; Battles, John J.; Fulweiler, Robinson W.

2017-03-01

Winter temperatures are projected to increase over the next century, leading to reductions in winter snowpack and increased frequency of soil freezing in many northern forest ecosystems. Here we examine biogenic silica (BSi) concentrations in sugar maple (Acer saccharum) fine roots collected from a snow manipulation experiment at Hubbard Brook Experimental Forest (New Hampshire, USA). Increased soil freezing significantly lowered the BSi content of sugar maple fine roots potentially decreasing their capacity to take up water and dissolved nutrients. The reduced silica uptake (8 ± 1 kmol silica km-2) by sugar maple fine roots is comparable to silica export from temperate forest watersheds. We estimate that fine roots account for 29% of sugar maple BSi, despite accounting for only 4% of their biomass. These results suggest that increased frequency of soil freezing will reduce silica uptake by temperate tree roots, thereby changing silica availability in downstream receiving waters.
Production and Application of Olivine Nano-Silica in Concrete

Science.gov (United States)

Mardiana, Oesman; Haryadi

2017-05-01

The aim of this research was to produce nano silica by synthesis of nano silica through extraction and dissolution of ground olivine rock, and applied the nano silica in the design concrete mix. The producing process of amorphous silica used sulfuric acid as the dissolution reagent. The separation of ground olivine rock occurred when the rock was heated in a batch reactor containing sulfuric acid. The results showed that the optimum mole ratio of olivine- acid was 1: 8 wherein the weight ratio of the highest nano silica generated. The heating temperature and acid concentration influenced the mass of silica produced, that was at temperature of 90 °C and 3 M acid giving the highest yield of 44.90%. Characterization using Fourier Transform Infrared (FTIR ) concluded that amorphous silica at a wavenumber of 1089 cm-1 indicated the presence of siloxane, Si-O-Si, stretching bond. Characterization using Scanning Electron Microscope - Energy Dispersive Spectroscopy (SEM-EDS) showed the surface and the size of the silica particles. The average size of silica particles was between 1-10 μm due to the rapid aggregation of the growing particles of nano silica into microparticles, caused of the pH control was not fully achieved.
[Effects of Rice Cultivar and Typical Soil Improvement Measures on the Uptake of Cd in Rice Grains].

Science.gov (United States)

Wang, Mei-e; Peng, Chi; Chen, Wei-ping

2015-11-01

Cadmium pollution of rice is a big problem in agricultural food safety. The accident "Cd rice" occurred last year in Youxian County, Hunan Province caused serious social panic. In this study, trials on "Cd rice" controlling techniques specific to the Cd pollution in paddy soil in Youxian were investigated. It was suggested that the average Cd contents in rice grains of the rice variety "Zhu Liang You 06" in Datongqiao and Wangling were 0.167 and 0.127 mg x kg(-1), respectively, which were only equal to 20% of the contents of other varieties. The trials for stabilizing agents revealed that treatments of lime and mineral fertilizer decreased Cd contents in rice grains to 20-30% of the control. Plastic film-mulched treatment decreased the rice grain Cd to 50%. And combined treatment of plastic film-mulched and biochar and silicon foliar-fertilizer decreased 80% of rice Cd content. Single treatments of silicon foliar-fertilizer and combined treatment of silicon foliar-fertilizer and topdressing fertilizer decreased more than 90% of Cd content. Results of BCR revealed that the percentage of cationic exchangeable and/or carbonate associated Cd fraction was more than 55% for most of the soil samples. Lime treatment significantly decreased the percentage of cationic exchangeable and/or carbonate and oxides of Fe and Mn associated Cd and increased the crystalline structure of clay minerals associated Cd. The change rate reached about 20%. Our results suggested concentration of soil Cd and pH were the two significant factors impacting the uptake of Cd by rice grains.
Rice Seedling Substrate Produced by Coal Gangue

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SHAO Yu-fei

2017-10-01

Full Text Available Peats are the mostly used material in making rice seedling substrate. However, mining peats could cause environmental problems. In order to reduce or replace peats in rice seedling substrate industry, this paper studied suitable way to configure rice seedling. The coal gangue was used to experiment cultivating rice. Four rice seeding experiments were carried out based on physical and chemical properties of materials attributes. The results showed:(1 Coal gangue was feasible for rice seedling; (2 The maximum adding amount of coal gangue was 80%(volume ratio though the coal gangue need to be activated; (3 In the case of no activated treatment only 38%(volume ratio of coal gangue could be added to the substrate.
Pumping Iron and Silica Bodybuilding

Science.gov (United States)

Mcnair, H.; Brzezinski, M. A.; Krause, J. W.; Parker, C.; Brown, M.; Coale, T.; Bruland, K. W.

2016-02-01

The availability of dissolved iron influences the stoichiometry of nutrient uptake by diatoms. Under nutrient replete conditions diatoms consume silicic acid and nitrate in a 1:1 ratio, this ratio increases under iron stress. Using the tracers 32Si and PDMPO, the total community and group-specific silica production rates were measured along a gradient of dissolved iron in an upwelling plume off the California coast. At each station, a control (ambient silicic acid) and +20 µM silicic acid treatment were conducted with each tracer to determine whether silicic acid limitation controlled the rate of silica production. Dissolved iron was 1.3 nmol kg-1 nearshore and decreased to 0.15 nmol kg-1 offshore. Silicic acid decreased more rapidly than nitrate, it was nearly 9 µM higher in the nearshore and 7 µM lower than nitrate in the middle of the transect where the iron concentration had decreased. The rate of diatom silica production decreased in tandem with silicic acid concentration, and silica production limitation by low silicic acid was most pronounced when iron concentrations were >0.4 nmol kg-1. The composition of the diatom assemblage shifted from Chaetoceros spp. dominated nearshore to a more sparse pennate-dominated assemblage offshore. Changes in taxa-specific silica production rates will be reported based on examination of PDMPO labeled cells using confocal microscopy.
Effect of silica particle size on macrophage inflammatory responses.

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Toshimasa Kusaka

Full Text Available Amorphous silica particles, such as nanoparticles (<100 nm diameter particles, are used in a wide variety of products, including pharmaceuticals, paints, cosmetics, and food. Nevertheless, the immunotoxicity of these particles and the relationship between silica particle size and pro-inflammatory activity are not fully understood. In this study, we addressed the relationship between the size of amorphous silica (particle dose, diameter, number, and surface area and the inflammatory activity (macrophage phagocytosis, inflammasome activation, IL-1β secretion, cell death and lung inflammation. Irrespective of diameter size, silica particles were efficiently internalized by mouse bone marrow-derived macrophages via an actin cytoskeleton-dependent pathway, and induced caspase-1, but not caspase-11, activation. Of note, 30 nm-1000 nm diameter silica particles induced lysosomal destabilization, cell death, and IL-1β secretion at markedly higher levels than did 3000 nm-10000 nm silica particles. Consistent with in vitro results, intra-tracheal administration of 30 nm silica particles into mice caused more severe lung inflammation than that of 3000 nm silica particles, as assessed by measurement of pro-inflammatory cytokines and neutrophil infiltration in bronchoalveolar lavage fluid of mice, and by the micro-computed tomography analysis. Taken together, these results suggest that silica particle size impacts immune responses, with submicron amorphous silica particles inducing higher inflammatory responses than silica particles over 1000 nm in size, which is ascribed not only to their ability to induce caspase-1 activation but also to their cytotoxicity.
Pecan drying with silica gel

Energy Technology Data Exchange (ETDEWEB)

Ghate, S.R.; Chhinnan, M.S.

1983-07-01

High moisture in-shell pecans were dried by keeping them in direct and indirect contact with silica gel to investigate their drying characteristics. In-shell pecans were also dried with ambient air from a controlled environment chamber and with air dehumidified by silica gel. Direct contact and dehumidified air drying seemed feasible approaches.
Pharmacogenetics in the Brazilian population

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Guilherme eSuarez-Kurtz

2010-10-01

Full Text Available Brazil is the 5th largest country in the world and its present population, in excess of 190 million, is highly heterogeneous, as a result of centuries of admixture between Amerindians, Europeans and Sub-Saharan Africans. The estimated individual proportions of biogeographical ancestry vary widely and continuously among Brazilians, most individuals - irrespective of self-identification as White, Brown or Black, the major categories of the Brazilian Census race/color system - having significant degrees of European and African ancestry, while a sizeable number display also Amerindian ancestry. These features have important pharmacogenetic (PGx implications: first, extrapolation of PGx data from relatively well-defined ethnic groups is clearly not applicable to the majority of Brazilians; second, the frequency distribution of polymorphisms in pharmacogenes (e.g. CYP3A5, CYP2C9, GSTM1, ABCB1, GSTM3, VKORC, etc varies continuously among Brazilians and is not captured by race/color self-identification; third, the intrinsic heterogeneity of the Brazilian population must be acknowledged in the design and interpretation of PGx studies in order to avoid spurious conclusions based on improper matching of study cohorts. The peculiarities of PGx in Brazilians are illustrated with data for different therapeutic groups, such as anticoagulants, HIV-protease inhibitors and nonsteroidal antinflammatory drugs, and the challenges and advantages created by population admixture for the study and implementation of PGx are discussed. PGx data for Amerindian groups and Brazilian-born, first generation Japanese are presented to illustrate the rich diversity of the Brazilian population. Finally, I introduce the reader to the Brazilian Pharmacogenetic Network or Refargen (www.refargen.org.br, a nationwide consortium of research groups, with the mission to provide leadership in PGx research and education in Brazil, with a population health impact.
Influence of organic solvents on interfacial water at surfaces of silica gel and partially silylated fumed silica

International Nuclear Information System (INIS)

Turov, V.V.; Gun'ko, V.M.; Tsapko, M.D.; Bogatyrev, V.M.; Skubiszewska-Zieba, J.; Leboda, R.; Ryczkowski, J.

2004-01-01

The effects of organic solvents (dimethylsulfoxide-d 6 (DMSO-d 6 ), chloroform-d, acetone-d 6 , and acetonitrile-d 3 ) on the properties of interfacial water at surfaces of silica gel Si-40 and partially silylated fumed silica A-380 were studied by means of the 1 H NMR spectroscopy with freezing-out of adsorbed water at 180 1 H NMR investigations were also analysed on the basis of the structural characteristics of silicas and quantum chemical calculations of the chemical shifts δ H and solvent effects. DMSO-d 6 and acetonitrile-d 3 are poorly miscible with water in silica gel pores in contrast to the bulk liquids. DMSO-d 6 and chloroform-d affect the structure of the interfacial water weaker than acetone-d 6 and acetonitrile-d 3 at amounts of liquids greater than the pore volume. Acetone-d 6 and acetonitrile-d 3 can displace water from pores under this condition. The chemical shift of protons in water adsorbed on silica gel is 3.5-6.5 ppm, which corresponds to the formation of two to four hydrogen bonds per molecule. Water adsorbed on partially silylated fumed silica has two 1 H NMR signals at 5 and 1.1-1.7 ppm related to different structures (droplets and small clusters) of the interfacial water
Silica and lung cancer: a controversial issue.

Science.gov (United States)

Pairon, J C; Brochard, P; Jaurand, M C; Bignon, J

1991-06-01

The role of crystalline silica in lung cancer has long been the subject of controversy. In this article, we review the main experimental and epidemiological studies dealing with this problem. Some evidence for a genotoxic potential of crystalline silica has been obtained in the rare in vitro studies published to date. In vivo studies have shown that crystalline silica is carcinogenic in the rat; the tumour types appear to vary according to the route of administration. In addition, an association between carcinogenic and fibrogenic potency has been observed in various animal species exposed to crystalline silica. An excess of lung cancer related to occupational exposure to crystalline silica is reported in many epidemiological studies, regardless of the presence of silicosis. However, most of these studies are difficult to interpret because they do not correctly take into account associated carcinogens such as tobacco smoke and other occupational carcinogens. An excess of lung cancer is generally reported in studies based on silicosis registers. Overall, experimental and human studies suggest an association between exposure to crystalline silica and an excess of pulmonary malignancies. Although the data available are not sufficient to establish a clear-cut causal relationship in humans, an association between the onset of pneumoconiosis and pulmonary malignancies is probable. In contrast, experimental observations have given rise to a pathophysiological mechanism that might account for a putative carcinogenic potency of crystalline silica.
Water culture of the rice containing Cs-137

International Nuclear Information System (INIS)

Choi, Yong Ho; Keum, Dong Kwon; Lim, Kwang Muk; Jun, In; Park, Doo Won

2008-10-01

Pot experiments were carried out in a greenhouse in order to produce Cs-137-containing rice seeds as a source material for use in manufacturing reference rice samples of a high Cs-137 activity. Two kinds of soil were used and two pots were prepared for each kind of soil. Rice plants were water-cultured in the pots and Cs-137 was applied to the surface water to induce a Cs-137 contamination of rice seeds via a plant uptake of Cs-137. Mature rice plants were harvested and Cs-137-containing rice seeds were obtained after some treatment of the harvested plants. These produced rice seeds are going to be provided for the KRISS so as to be used in manufacturing reference rice samples for Cs-137
Diurnal variation of methane emission from a paddy field in Brazilian Southeast

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Magda Aparecida de Lima

2018-04-01

Full Text Available ABSTRACT: This study aimed to investigate the diurnal variation of methane (CH4 emission in a flooded-irrigated rice field at different stages of the plant development under tropical climate in three growing seasons, in order to determine the most appropriate time for gas sampling in the Brazilian Southeast region. It aimed also to verify correlations between CH4 flux and air, water and soil temperatures, and solar radiation. The CH4 emissions were measured every 3-hour interval on specific days in different development stages of the flooded rice in the Experiment Station of the Agência Paulista de Tecnologia dos Agronegócios (APTA, Pólo Regional Vale do Paraíba, at Pindamonhangaba, State of São Paulo (22°55’ S, 45°30’ W, Brazil. Different CH4 emission rates were observed among the plant growth stages and also among the growing seasons. The CH4 emission showed high correlation with the soil temperature at 2cm depth. At this depth, the CH4 emission activation energy in response to soil temperature was higher in the stage R2. Emission peaks were observed at afternoon, while lower fluxes were recorded at the early morning. The most appropriate local time for gas sampling was estimated at 12:11:15a.m.±01:14:16 and 09:05:49p.m.±01:29:04.
Effect of Temperature on Chinese Rice Wine Brewing with High Concentration Presteamed Whole Sticky Rice

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Dengfeng Liu

2014-01-01

Full Text Available Production of high quality Chinese rice wine largely depends on fermentation temperature. However, there is no report on the ethanol, sugars, and acids kinetics in the fermentation mash of Chinese rice wine treated at various temperatures. The effects of fermentation temperatures on Chinese rice wine quality were investigated. The compositions and concentrations of ethanol, sugars, glycerol, and organic acids in the mash of Chinese rice wine samples were determined by HPLC method. The highest ethanol concentration and the highest glycerol concentration both were attained at the fermentation mash treated at 23°C. The highest peak value of maltose (90 g/L was obtained at 18°C. Lactic acid and acetic acid both achieved maximum values at 33°C. The experimental results indicated that temperature contributed significantly to the ethanol production, acid flavor contents, and sugar contents in the fermentation broth of the Chinese rice wines.

Malaysian weedy rice shows its true stripes: wild Oryza and elite rice cultivars shape agricultural weed evolution in Southeast Asia.

Science.gov (United States)

Song, Beng-Kah; Chuah, Tse-Seng; Tam, Sheh May; Olsen, Kenneth M

2014-10-01

Weedy rice is a close relative of domesticated rice (Oryza sativa) that competes aggressively with the crop and limits rice productivity worldwide. Most genetic studies of weedy rice have focused on populations in regions where no reproductively compatible wild Oryza species occur (North America, Europe and northern Asia). Here, we examined the population genetics of weedy rice in Malaysia, where wild rice (O. rufipogon) can be found growing in close proximity to cultivated and weedy rice. Using 375 accessions and a combined analysis of 24 neutral SSR loci and two rice domestication genes (sh4, controlling seed shattering, and Bh4, controlling hull colour), we addressed the following questions: (i) What is the relationship of Malaysian weedy rice to domesticated and wild rice, and to weedy rice strains in the USA? (ii) To what extent does the presence of O. rufipogon influence the genetic and phenotypic diversity of Malaysian weeds? (iii) What do the distributions of sh4 and Bh4 alleles and associated phenotypes reveal about the origin and contemporary evolution of Malaysian weedy rice? Our results reveal the following: independent evolutionary origins for Malaysian weeds and US strains, despite their very close phenotypic resemblance; wild-to-weed gene flow in Malaysian weed populations, including apparent adaptive introgression of seed-shattering alleles; and a prominent role for modern Malaysian cultivars in the origin and recent proliferation of Malaysian weeds. These findings suggest that the genetic complexity and adaptability of weedy crop relatives can be profoundly influenced by proximity to reproductively compatible wild and domesticated populations. © 2014 John Wiley & Sons Ltd.
Simultaneous rough rice drying and rice bran stabilization using infrared radiation heating

Science.gov (United States)

The objective of this study was to develop a new rice drying method by using IR heating followed by tempering. Freshly harvested medium grain rice (M206) samples with different initial moisture contents (IMCs) were used in this study. The samples were dried for one- and two-passes by using a catalyt...
Genetic analysis of rice blast disease resistance genes using USDA rice mini-core and a mapping population

Science.gov (United States)

Rice blast disease caused by the fungal pathogen Magnaporthe oryzae (M. oryzae) is one of the most destructive diseases of cultivated rice, resulting in significant yield loss each year all over the world. Developing and utilizing blast resistant rice varieties is the most economical and effective m...
Comparing the costs and benefits of floating rice-based and intensive rice-based farming systems in the Mekong delta

OpenAIRE

Van Kien Nguyen; Oc Van Vo; Duc Ngoc Huynh

2015-01-01

This paper compares financial costs and benefits of floating rice-based and intensive rice farming systems using data from focus group discussions and household survey in four locations in the Mekong Delta. We argue that the net financial benefit per 1000m2 of integrated floating rice-based farming systems is greater than the net financial benefit of intensive rice farming system. The total net benefit of floating rice-leeks shows the highest net benefit (VND 24.8 mil./1000 m2), followed by f...
Investigation of SiO{sub 2}:Na{sub 2}O ratio as a corrosion inhibitor for metal alloys

Energy Technology Data Exchange (ETDEWEB)

Mohamad, N.; Othman, N. K. [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor Darul Ehsan (Malaysia); Jalar, A. [Institute of Micro Engineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor Darul Ehsan (Malaysia)

2013-11-27

The silicate is one of the potential compounds used as a corrosion inhibitor for metal alloys. The mixture between silica and sodium hydroxide (NaOH) succeeded to produce the silicate product. The formulation of a silicate product normally variable depended by the different ratio of SiO{sub 2}:Na{sub 2}O. This research utilized the agriculture waste product of paddy using its rice husk. In this study, the amorphous silica content in rice husk ash was used after rice husk burnt in a muffle furnace at a certain temperature. The X-ray diffraction (XRD) analysis was done to determine the existence of amorphous phase of silica in the rice husk ash. There are several studies that recognized rice husk as an alternative source that obtained high silica content. The X-ray fluorescence (XRF) analysis was carried out to clarify the percentage amount of Si and O elements, which referred the silica compound in rice husk ash. The preparation of sodium silicate formulation were differ based on the SiO{sub 2}:Na{sub 2}O ratio (SiO{sub 2}:Na{sub 2}O ratio = 1.00, 2.00 and 3.00). These silicate based corrosion inhibitors were tested on several testing samples, which were copper (99.9%), aluminum alloy (AA 6061) and carbon steel (SAE 1045). The purpose of this study is to determine the appropriate SiO{sub 2}:Na{sub 2}O ratio and understand how this SiO{sub 2}:Na{sub 2}O ratio can affect the corrosion rate of each metal alloys immersed in acidic medium. In order to investigate this study, weight loss test was conducted in 0.5 M hydrochloric acid (HCl) for 24 hours at room temperature.
The puzzle of Italian rice origin and evolution: determining genetic divergence and affinity of rice germplasm from Italy and Asia.

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Xingxing Cai

Full Text Available The characterization of genetic divergence and relationships of a set of germplasm is essential for its efficient applications in crop breeding and understanding of the origin/evolution of crop varieties from a given geographical region. As the largest rice producing country in Europe, Italy holds rice germplasm with abundant genetic diversity. Although Italian rice varieties and the traditional ones in particular have played important roles in rice production and breeding, knowledge concerning the origin and evolution of Italian traditional varieties is still limited. To solve the puzzle of Italian rice origin, we characterized genetic divergence and relationships of 348 rice varieties from Italy and Asia based on the polymorphisms of microsatellite fingerprints. We also included common wild rice O. rufipogon as a reference in the characterization. Results indicated relatively rich genetic diversity (H(e = 0.63-0.65 in Italian rice varieties. Further analyses revealed a close genetic relationship of the Italian traditional varieties with those from northern China, which provides strong genetic evidence for tracing the possible origin of early established rice varieties in Italy. These findings have significant implications for the rice breeding programs, in which appropriate germplasm can be selected from a given region and utilized for transferring unique genetic traits based on its genetic diversity and evolutionary relationships.
New Silica Magnetite Sorbent: The Influence of Variations of Sodium Silicate Concentrations on Silica Magnetite Character

Science.gov (United States)

Azmiyawati, C.; Pratiwi, P. I.; Darmawan, A.

2018-04-01

The adsorption capacity of an adsorbent is determined by the adsorbent and the adsorbate properties. The character of the adsorbent will play a major role in its ability to adsorb the corresponding adsorbate. Therefore, in this study we looked at the effects of variations of sodium silicate concentrations on the resulting magnetite silica adsorbent properties. The application of silica coating on the magnetite was carried out through a sol-gel process with sodium silicate and HCl precursors. Based on the characterization data obtained, it was found that the silica coating on magnetite can increase the resistance to acid leaching, increase the particle size, but decrease the magnetic properties of the magnetite. Based on Gas Sorption Analyzer (GSA) and X-ray Difraction (XRD) data it can successively be determined that increase in concentration of sodium silicate will increase the surface area and amorphous structure of the Silica Magnetie.
Dispersibility of silica fume in mortar and its effect on properties of mortar. Silica fume no bunsan to mortar no shotokusei

Energy Technology Data Exchange (ETDEWEB)

Oga, H; Uomoto, T [The University of Tokyo, Tokyo (Japan). Institute of Industrial Science

1992-08-01

Effect of silica fume dispersibility on concrete characteristics was discussed. Properties of mortar mixed with silica fume to exhibit compression strength varied with displacement rates, patterns, and mixing time of silica fume. In submerged curing age of 28 days, the compression strength in a mortar mixed with silica fume at 10% was affected only very little by the mixing time for both pelletizing and non-pelletizing types for up to 180 seconds. The strength increased thereafter with the mixing time. The compression strength at 1020 seconds showed higher value by about 150 kgf/cm [sup 2] than when no silica fume is added, with a difference because of patterns disappearing. In the case of a mixing time of 1020 seconds, neutralization depth receives very little effect from a pattern difference, and decreases with increasing displacement rate. Neutralization coefficient of the mortar mixed with silica fume at 10% decreased with the mixing time, and it was possible to suppress the neutralization coefficient to 25% of the case without silica fume addition in a 1020-second mixing. 7 refs., 8 figs., 1 tab.
Succession of methanogenic archaea in rice straw incorporated into a Japanese rice field: estimation by PCR-DGGE and sequence analyses

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Atsuo Sugano

2005-01-01

Full Text Available The succession and phylogenetic profiles of methanogenic archaeal communities associated with rice straw decomposition in rice-field soil were studied by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE analysis followed by 16S rDNA sequencing. Nylon bags containing either leaf sheaths or blades were buried in the plowed layer of a Japanese rice field under drained conditions during the off-crop season and under flooded conditions after transplanting. In addition, rice straw samples that had been buried in the rice field under drained conditions during the off-crop season were temporarily removed during spring plowing and then re-buried in the same rice field under flooded conditions at transplanting. Populations of methanogenic archaea were examined by amplification of the 16S rRNA genes in the DNA extracted from the rice straw samples. No PCR product was produced for samples of leaf sheath or blade prior to burial or after burial under drained conditions, indicating that the methanogen population was very small during decomposition of rice straw under oxic conditions. Many common bands were observed in rice straw samples of leaf sheath and blade during decomposition of rice straw under flooded conditions. Cluster analysis based on DGGE patterns divided methanogenic archaeal communities into two groups before and after the mid-season drainage. Sequence analysis of DGGE bands that were commonly present were closely related to Methanomicrobiales and Rice cluster I. Methanomicrobiales, Rice cluster I and Methanosarcinales were major members before the mid-season drainage, whereas the DGGE bands that characterized methanogenic archaeal communities after the mid-season drainage were closely related to Methanomicrobiales. These results indicate that mid-season drainage affected the methanogenic archaeal communities irrespective of their location on rice straw (sheath and blade and the previous history of decomposition
Rice DB: an Oryza Information Portal linking annotation, subcellular location, function, expression, regulation, and evolutionary information for rice and Arabidopsis.

Science.gov (United States)

Narsai, Reena; Devenish, James; Castleden, Ian; Narsai, Kabir; Xu, Lin; Shou, Huixia; Whelan, James

2013-12-01

Omics research in Oryza sativa (rice) relies on the use of multiple databases to obtain different types of information to define gene function. We present Rice DB, an Oryza information portal that is a functional genomics database, linking gene loci to comprehensive annotations, expression data and the subcellular location of encoded proteins. Rice DB has been designed to integrate the direct comparison of rice with Arabidopsis (Arabidopsis thaliana), based on orthology or 'expressology', thus using and combining available information from two pre-eminent plant models. To establish Rice DB, gene identifiers (more than 40 types) and annotations from a variety of sources were compiled, functional information based on large-scale and individual studies was manually collated, hundreds of microarrays were analysed to generate expression annotations, and the occurrences of potential functional regulatory motifs in promoter regions were calculated. A range of computational subcellular localization predictions were also run for all putative proteins encoded in the rice genome, and experimentally confirmed protein localizations have been collated, curated and linked to functional studies in rice. A single search box allows anything from gene identifiers (for rice and/or Arabidopsis), motif sequences, subcellular location, to keyword searches to be entered, with the capability of Boolean searches (such as AND/OR). To demonstrate the utility of Rice DB, several examples are presented including a rice mitochondrial proteome, which draws on a variety of sources for subcellular location data within Rice DB. Comparisons of subcellular location, functional annotations, as well as transcript expression in parallel with Arabidopsis reveals examples of conservation between rice and Arabidopsis, using Rice DB (http://ricedb.plantenergy.uwa.edu.au). © 2013 The Authors The Plant Journal © 2013 John Wiley & Sons Ltd.
PICTORIAL INTERLUDES Flake-shaped rice bodies

African Journals Online (AJOL)

removing the rice bodies and the bursa.3. In summary: rice bodies can occur without underlying systemic disorder, have different shapes and sizes, and have specific signal characteristics on. MRI that allow discrimination from synovial chondromatosis. 1. Cheung HS, Ryan LM, Kozin F, McCarty DJ. Synovial origins of rice ...
Synthesis of Silica Nanoparticles by Sol-Gel: Size-Dependent Properties, Surface Modification, and Applications in Silica-Polymer Nano composites-A Review

International Nuclear Information System (INIS)

Ismail, A.R.; Vejayakumaran, P.

2012-01-01

Application of silica nanoparticles as fillers in the preparation of nano composite of polymers has drawn much attention, due to the increased demand for new materials with improved thermal, mechanical, physical, and chemical properties. Recent developments in the synthesis of monodispersed, narrow-size distribution of nanoparticles by sol-gel method provide significant boost to development of silica-polymer nano composites. This paper is written by emphasizing on the synthesis of silica nanoparticles, characterization on size-dependent properties, and surface modification for the preparation of homogeneous nano composites, generally by sol-gel technique. The effect of nano silica on the properties of various types of silica-polymer composites is also summarized.
Silica sol as grouting material: a physio-chemical analysis.

Science.gov (United States)

Sögaard, Christian; Funehag, Johan; Abbas, Zareen

2018-01-01

At present there is a pressing need to find an environmentally friendly grouting material for the construction of tunnels. Silica nanoparticles hold great potential of replacing the organic molecule based grouting materials currently used for this purpose. Chemically, silica nanoparticles are similar to natural silicates which are essential components of rocks and soil. Moreover, suspensions of silica nanoparticles of different sizes and desired reactivity are commercially available. However, the use of silica nanoparticles as grouting material is at an early stage of its technological development. There are some critical parameters such as long term stability and functionality of grouted silica that need to be investigated in detail before silica nanoparticles can be considered as a reliable grouting material. In this review article we present the state of the art regarding the chemical properties of silica nanoparticles commercially available, as well as experience gained from the use of silica as grouting material. We give a detailed description of the mechanisms underlying the gelling of silica by different salt solutions such as NaCl and KCl and how factors such as particle size, pH, and temperature affect the gelling and gel strength development. Our focus in this review is on linking the chemical properties of silica nanoparticles to the mechanical properties to better understand their functionality and stability as grouting material. Along the way we point out areas which need further research.
Preparation of thick silica coatings on carbon fibers with fine-structured silica nanotubes induced by a self-assembly process

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Benjamin Baumgärtner

2017-05-01

Full Text Available A facile method to coat carbon fibers with a silica shell is presented in this work. By immobilizing linear polyamines on the carbon fiber surface, the high catalytic activity of polyamines in the sol–gel-processing of silica precursors is used to deposit a silica coating directly on the fiber’s surface. The surface localization of the catalyst is achieved either by attaching short-chain polyamines (e.g., tetraethylenepentamine via covalent bonds to the carbon fiber surface or by depositing long-chain polyamines (e.g., linear poly(ethylenimine on the carbon fiber by weak non-covalent bonding. The long-chain polyamine self-assembles onto the carbon fiber substrate in the form of nanoscopic crystallites, which serve as a template for the subsequent silica deposition. The silicification at close to neutral pH is spatially restricted to the localized polyamine and consequently to the fiber surface. In case of the linear poly(ethylenimine, silica shells of several micrometers in thickness can be obtained and their morphology is easily controlled by a considerable number of synthesis parameters. A unique feature is the hierarchical biomimetic structure of the silica coating which surrounds the embedded carbon fiber by fibrillar and interconnected silica fine-structures. The high surface area of the nanostructured composite fiber may be exploited for catalytic applications and adsorption purposes.
Rice methylmercury exposure and mitigation: a comprehensive review.

Science.gov (United States)

Rothenberg, Sarah E; Windham-Myers, Lisamarie; Creswell, Joel E

2014-08-01

Rice cultivation practices from field preparation to post-harvest transform rice paddies into hot spots for microbial mercury methylation, converting less-toxic inorganic mercury to more-toxic methylmercury, which is likely translocated to rice grain. This review includes 51 studies reporting rice total mercury and/or methylmercury concentrations, based on rice (Orzya sativa) cultivated or purchased in 15 countries. Not surprisingly, both rice total mercury and methylmercury levels were significantly higher in polluted sites compared to non-polluted sites (Wilcoxon rank sum, p<0.001). However, rice percent methylmercury (of total mercury) did not differ statistically between polluted and non-polluted sites (Wilcoxon rank sum, p=0.35), suggesting comparable mercury methylation rates in paddy soil across these sites and/or similar accumulation of mercury species for these rice cultivars. Studies characterizing the effects of rice cultivation under more aerobic conditions were reviewed to determine the mitigation potential of this practice. Rice management practices utilizing alternating wetting and drying (instead of continuous flooding) caused soil methylmercury levels to spike, resulting in a strong methylmercury pulse after fields were dried and reflooded; however, it is uncertain whether this led to increased translocation of methylmercury from paddy soil to rice grain. Due to the potential health risks, it is advisable to investigate this issue further, and to develop separate water management strategies for mercury polluted and non-polluted sites, in order to minimize methylmercury exposure through rice ingestion. Copyright © 2014 Elsevier Inc. All rights reserved.
Ordered nanoporous silica as carriers for improved delivery of water insoluble drugs: a comparative study between three dimensional and two dimensional macroporous silica

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Wang Y

2013-10-01

Full Text Available Ying Wang, Qinfu Zhao, Yanchen Hu, Lizhang Sun, Ling Bai, Tongying Jiang, Siling WangDepartment of Pharmaceutics, Shenyang Pharmaceutical University, Liaoning Province, People’s Republic of ChinaAbstract: The goal of the present study was to compare the drug release properties and stability of the nanoporous silica with different pore architectures as a matrix for improved delivery of poorly soluble drugs. For this purpose, three dimensional ordered macroporous (3DOM silica with 3D continuous and interconnected macropores of different sizes (200 nm and 500 nm and classic mesoporous silica (ie, Mobil Composition of Matter [MCM]-41 and Santa Barbara Amorphous [SBA]-15 with well-ordered two dimensional (2D cylindrical mesopores were successfully fabricated and then loaded with the model drug indomethacin (IMC via the solvent deposition method. Scanning electron microscopy (SEM, N2 adsorption, differential scanning calorimetry (DSC, and X-ray diffraction (XRD were applied to systematically characterize all IMC-loaded nanoporous silica formulations, evidencing the successful inclusion of IMC into nanopores, the reduced crystallinity, and finally accelerated dissolution of IMC. It was worth mentioning that, in comparison to 2D mesoporous silica, 3DOM silica displayed a more rapid release profile, which may be ascribed to the 3D interconnected pore networks and the highly accessible surface areas. The results obtained from the stability test indicated that the amorphous state of IMC entrapped in the 2D mesoporous silica (SBA-15 and MCM-41 has a better physical stability than in that of 3DOM silica. Moreover, the dissolution rate and stability of IMC loaded in 3DOM silica was closely related to the pore size of macroporous silica. The colorimetric 3-(4,5-Dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT and Cell Counting Kit (CCK-8 assays in combination with direct morphology observations demonstrated the good biocompatibility of nanoporous
Brazilian readers and contextual reference Brazilian readers and contextual reference

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Lilia M. O. Carioni

2008-04-01

Full Text Available This article describes an experiment carried out using Brazilian university students at UFSC, the purpose being to check comprehension relationships between two types of contextual reference and two languages, Portuguese and English. A major stimulus for the research was the question: are Brazilian students' difficulties in reading English related more to English language difficulties or to difficulties in processing text in general?
Translocations of 2,4-D-14C Herbicides In Weed And Rice Plant On Irrigated Rice Field System

International Nuclear Information System (INIS)

Chairul, Sofnie M.; Idawati; Mulyadi

2000-01-01

The investigation of translocation 2,4-D herbicides using 14 C as tracer on irradiated rice plant system. Condition of the soil was two kinds, that is normal soil and soil 30% up normal. The soil of rice field was spray with 1μCi of 2,4-D non labelled, one week after planting. A part of rice plant and weed was determined the radioactivity after 0, 2, 4, 8, and 10 weeks after spraying. The result showed that radioactivity maximum after zero week was in root and leaf of weeds, the second weeks in root of rice, the forth weeks in rice stick, and eighth weeks in leaf of rice. This result occur at normal condition soil of solid 30 % up normal soil. The residues of 2.4-D in rice was 4,24x10 -3 ppb at normal soil and 3.16x10 -3 ppb at solid 30% up normal soil. This result still lower than rate of WHO/FAO, that is 0,05 ppm
Sustainable rice production in Malaysia beyond 2000

International Nuclear Information System (INIS)

Nashriyah Mat; Ho Nai Kin; Ismail Sahid; Ahyaudin Ali; Lum Keng Yeang; Mashhor Mansor

2002-01-01

This book is a compendium of works carried out by various institutions on subjects related to sustainable rice production. The institutions comprise Department of Agriculture, Malaysian Agricultural Research and Development Institute, Malaysian Institute for Nuclear Technology Research, Muda Agricultural Development Authority, Universiti Kebangsaan Malaysia, Universiti Putra Malaysia, Universiti Sains Malaysia, International Islamic University of Malaysia and the Agrochemical Company Mosanto. Integrated Biodiversity Management parallel with the Integrated Weed / Pest / Disease Management, rice-fish farming networking, agrochemical residue monitoring in rice and marine ecosystems, and application of biotechnology in rice productivity are taken as the future direction towards achieving sustainable rice production beyond 2000. Challenges from social and technical agroecosystem constraints, agricultural input management and maintenance of agroecosystem biodiversity are highlighted. It is imperative that the challenges are surmounted to attain the target that would be reflected by tangible rice output of 10 t/ha, and at the same time maintaining the well-being of rice-farmers. (Author)
Measurement and modelization of silica opal optical properties

OpenAIRE

Avoine , Amaury; Ngoc Hong , Phan; Frederich , Hugo; Aregahegn , Kifle; Bénalloul , Paul; Coolen , Laurent; Schwob , Catherine; Thu Nga , Pham; Gallas , Bruno; Maître , Agnès

2014-01-01

International audience; We present the synthesis process and optical characterization of artificial silica opals. The specular reflection spectra are analyzed and compared to band structure calculations and finite difference time domain (FDTD) simulations. The silica optical index is a key parameter to correctly describe an opal and is usually not known and treated as a free parameter. Here we propose a method to infer the silica index, as well as the silica spheres diameter, from the reflect...

Clustering of 18 Local Black Rice Base on Total Anthocyanin

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Kristamtini Kristamtini

2017-10-01

Full Text Available Black rice has a high anthocyanin content in the pericarp layer, which provides a dark purple color. Anthocyanin serve as an antioxidant that control cholesterol level in the blood, prevent anemia, potentially improve the body's resistance to disease, improve damage to liver cells (hepatitis and chirrosis, prevent impaired kidney function, prevent cancer/tumors, slows down antiaging, and prevent atherosclerosis and cardiovascular disease. Exploration results at AIAT Yogyakarta, Indonesia from 2011 to 2014 obtained 18 cultivar of local black rice Indonesia. The names of the rice are related to the color (black, red or purple formed by anthocyanin deposits in the pericarp layer, seed coat or aleuron. The objective of the study was to classify several types of local black rice from explorations based on the total anthocyanin content. The study was conducted by clustering analyzing the total anthocyanin content of 18 local black rice cultivars in Indonesia. Cluster analysis of total anthocyanin content were done using SAS ver. 9.2. Clustering dendogram shows that there were 4 groups of black rice cultivars based on the total anthocyanin content. Group I consists of Melik black rice, Patalan black rice, Yunianto black rice, Muharjo black rice, Ngatijo black rice, short life of Tugiyo black rice, Andel hitam 1, Jlitheng, and Sragen black rice. Group II consists of Pari ireng, Magelang black hairy rice, Banjarnegara-Wonosobo black rice, and Banjarnegara black rice. Group III consists of NTT black rice, Magelang non hairy black rice, Sembada hitam, and longevity Tugiyo black rice. Group IV consist only one type of black rice namely Cempo ireng. The grouping result indicate the existence of duplicate names among the black rice namely Patalan with Yunianto black rice, and short life Tugiyo with Andel hitam 1 black rice.
Functionalized mesoporous silica materials for molsidomine adsorption: Thermodynamic study

International Nuclear Information System (INIS)

Alyoshina, Nonna A.; Parfenyuk, Elena V.

2013-01-01

A series of unmodified and organically modified mesoporous silica materials was prepared. The unmodified mesoporous silica was synthesized via sol–gel synthesis in the presence of D-glucose as pore-forming agent. The functionalized by phenyl, aminopropyl and mercaptopropyl groups silica materials were prepared via grafting. The fabricated adsorbent materials were characterized by Fourier transform infrared spectroscopy (FTIR) analysis, N 2 adsorption/desorption and elemental analysis methods. Then their adsorption properties for mesoionic dug molsidomine were investigated at 290–313 K and physiological pH value. Thermodynamic parameters of molsidomine adsorption on the synthesized materials have been calculated. The obtained results showed that the adsorption process of molsidomine on the phenyl modified silica is the most quantitatively and energetically favorable. The unmodified and mercaptopropyl modified silica materials exhibit significantly higher adsorption capacities and energies for molsidomine than the aminopropyl modified sample. The effects are discussed from the viewpoint of nature of specific interactions responsible for the adsorption. - Graphical abstract: Comparative analysis of the thermodynamic characteristics of molsidomine adsorption showed that the adsorption process on mesoporous silica materials is controlled by chemical nature of surface functional groups. Molsidomine adsorption on the phenyl modified silica is the most quantitatively and energetically favorable. Taking into account ambiguous nature of mesoionic compounds, it was found that molsidomine is rather aromatic than dipolar. Display Omitted - Highlights: • Unmodified and organically modified mesoporous silica materials were prepared. • Molsidomine adsorption on the silica materials was studied. • Phenyl modified silica shows the highest adsorption capacity and favorable energy. • Molsidomine exhibits the lowest affinity to aminopropyl modified silica
Recent advances on bioactivities of black rice.

Science.gov (United States)

Dias, Aécio L de S; Pachikian, Barbara; Larondelle, Yvan; Quetin-Leclercq, Joëlle

2017-11-01

Black rice has been consumed for centuries in Asian countries such as China, Korea or Japan. Nowadays, extracts and derivatives are considered as beneficial functional foods because of their high content in several bioactive molecules such as anthocyanins, other phenolics and terpenoids. The purpose of this review is to summarize and discuss recent developments on black rice bioactivities. Some sterols and triterpenoids with potential anticancer properties already tested in vitro and in vivo have been isolated and identified from bran extracts of black rice. Protection against osteoporosis has been suggested for the first time for black rice extracts. Because of its antioxidant and anti-inflammatory properties, black rice also protects liver and kidney from injuries. One clinical study reported the interest of black rice in case of alcohol withdrawal. Several advances have been recently achieved on the understanding of the potential biological effects of black rice and its derivatives. They further confirm that black rice should be considered as a promising source of health-promoting functional foods targeting a large set of noninfectious diseases. However, more clinical studies are needed to support the findings highlighted in this review.
Life Expectancy of Brazilian Neurosurgeons.

Science.gov (United States)

Botelho, Ricardo Vieira; Jardim Miranda, Bárbara Cristina; Nishikuni, Koshiro; Waisberg, Jaques

2018-06-01

Life expectancy (LE) refers to the number of years that an individual is expected to survive. Emphasis is frequently placed on the relationship between LE and the conditions under which a population lives, but fewer studies have investigated the relationship between stress factors associated with specific professions and their effects on LE. The aim of this study is to evaluate Brazilian neurosurgeons' life expectancies (BNLEs) and compare them with those of physicians (both Brazilian and foreign) from other fields, as well as with Brazilian nondoctors. The Brazilian Society of Neurosurgery death registry was used to obtain data that compared LEs from non-neurosurgeon physicians, as described in the national and international literature. BNLEs were also compared with the LEs of Brazilian citizens. Fifty-one neurosurgeons died between 2009 and 2016. All were males. The mean age at death was 68.31 ± 17.71 years. Among all-cause mortality, the breakdown was 20% cardiovascular diseases, 39% malignancies, 10% external factors, 6% gastrointestinal disorders, 12% neurologic illnesses, and 14% unknown causes. BNLE was shorter than LE of male Brazilian citizens. LE was similar among neurosurgeons and other doctors but shorter compared with Brazilian citizens. Further research is needed to provide data that can add to and confirm these results. Copyright © 2018 Elsevier Inc. All rights reserved.
Synthesis and Gas Transport Properties of Hyperbranched Polyimide–Silica Hybrid/Composite Membranes

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Masako Miki

2013-12-01

Full Text Available Hyperbranched polyimide–silica hybrids (HBPI–silica HBDs and hyperbranched polyimide–silica composites (HBPI–silica CPTs were prepared, and their general and gas transport properties were investigated to clarify the effect of silica sources and preparation methods. HBPI–silica HBDs and HBPI–silica CPTs were synthesized by two-step polymerization of A2 + B3 monomer system via polyamic acid as precursor, followed by hybridizing or blending silica sources. Silica components were incorporated by the sol-gel reaction with tetramethoxysilane (TMOS or the addition of colloidal silica. In HBPI-silica HBDs, the aggregation of silica components is controlled because of the high affinity of HBPI and silica caused by the formation of covalent bonds between HBPI and silica. Consequently, HBPI-silica HBDs had good film formability, transparency, and mechanical properties compared with HBPI-silica CPTs. HBPI-silica HBD and CPT membranes prepared via the sol-gel reaction with TMOS showed specific gas permeabilities and permselectivities for CO2/CH4 separation, that is, both CO2 permeability and CO2/CH4 selectivity increased with increasing silica content. This result suggests that gas transport can occur through a molecular sieving effect of the porous silica network derived from the sol-gel reaction and/or through the narrow interfacial region between the silica networks and the organic matrix.
Rice is the seed of the monocot plants Oryza sativa (Asian rice) or ...

African Journals Online (AJOL)

BIOTECH

2013-10-16

Oct 16, 2013 ... of culture. The regenerated plantlets were transferred to pots for acclimatization. About 80% of plants were survived in the greenhouse condition. Key words: Somatic embryogenesis, immature zygotic embryos, Indica rice, plant regeneration. INTRODUCTION. Rice (Oryza sativa L.) is one of the most ...
A Mixed-Methods Study on Acceptability, Tolerability, and Substitution of Brown Rice for White Rice to Lower Blood Glucose Levels among Nigerian Adults

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Sally N. Adebamowo

2017-07-01

Full Text Available BackgroundWhole-grain products such as brown rice have been associated with lower risk of metabolic disorders including diabetes. We examined the acceptability and tolerability of substituting brown rice for white rice and the feasibility of introducing brown rice into the diet through a long-term trial to lower the risk of type 2 diabetes.MethodsFifty-one adults residing in Abuja, Nigeria, participated in this study. Using purposeful sampling for focus group discussions (FGDs, participants were enrolled based on their age (19–25 vs. 40–60 years and body mass index (BMI (normal weight vs. overweight/obese. Participants tasted four meals with different constitution of brown and white rice (25:75%, 50:50%, 75:25%, and 100% brown rice. Twelve FGDs were conducted, six before and six after the food tasting. Two-hour postprandial blood glucose was measured after consumption of each rice meal.ResultsThe mean age of the participants was 39 (±14 years, their mean BMI was 25.6 (±5.2 and about half of them were male. Most of the participants (61% reported that rice was their main source of carbohydrate and 67% consumed rice at least five times/week. Before the food tasting, participants considered white polished rice superior to brown rice with regard to quality, taste, and nutritional value. After the food tasting, most of the participants (49% indicated a preference for the 100% brown rice, 19% preferred the 25% brown rice, 18% preferred the 50% brown rice, and 7% preferred the 75% brown rice meals. Factors that may affect the acceptability of brown rice include its appearance, longer cooking time, cost, limited availability, and poor appreciation of its nutritional value. In general, 2-h postprandial glucose levels were lower, after consumption of meals with higher proportion of brown rice.ConclusionThis study provides valuable insight into the acceptability of brown rice as a substitute for white rice in Nigeria. If confirmed in larger studies
The Brazilian Nuclear Energy Program

International Nuclear Information System (INIS)

Carvalho, H.G. de

1980-01-01

A survey is initially of the international-and national situation regarding energetic resources. The Brazilian Nuclear Energy Policy and the Brazilian Nuclear Program are dealt with, as well as the Nuclear Cooperation agreement signed with the Federal Republic of Germany. The situation of Brazil regarding Uranium and the main activities of the Brazilian Nuclear Energy Commission are also discussed [pt
Functionalized Mesoporous Silica Membranes for CO2 Separation Applications

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Hyung-Ju Kim

2015-01-01

Full Text Available Mesoporous silica molecular sieves are emerging candidates for a number of potential applications involving adsorption and molecular transport due to their large surface areas, high pore volumes, and tunable pore sizes. Recently, several research groups have investigated the potential of functionalized mesoporous silica molecular sieves as advanced materials in separation devices, such as membranes. In particular, mesoporous silica with a two- or three-dimensional pore structure is one of the most promising types of molecular sieve materials for gas separation membranes. However, several important challenges must first be addressed regarding the successful fabrication of mesoporous silica membranes. First, a novel, high throughput process for the fabrication of continuous and defect-free mesoporous silica membranes is required. Second, functionalization of mesopores on membranes is desirable in order to impart selective properties. Finally, the separation characteristics and performance of functionalized mesoporous silica membranes must be further investigated. Herein, the synthesis, characterization, and applications of mesoporous silica membranes and functionalized mesoporous silica membranes are reviewed with a focus on CO2 separation.
Development of Rice Reprocessing to Strengthen Small Scale Rice Mills in Indramayu West Java

Science.gov (United States)

Firdaus, Y. R.; Hasbullah, R.; Djohar, S.

2018-05-01

Small Rice Mill (SRM) has a very important role in rice production of strong institutional relationships to farmers and rice markets. Nevertheless, the rice produced in low quality and changing consumer preferences cause SRM to have difficulty in maintaining the role. Development of a reprocessing business - called Rice to Rice Processing Plant (R2RP) - as a separate business unit will support their role and existence. This study aimed at analyzing the feasibility of R2RP business that integrates SRM and market as an independent business unit and determines mutual partnership pattern. The study was conducted with special reference to West Java Province. The qualitative method used for non-financial aspects analysis includes raw material, market, technical-technological, management and regulation and partnership pattern. The financial aspect used the quantitative method of Net Present Value (NPV), Net Benefit Cost Ratio (Net B/C), Internal Rate of Return (IRR), Payback Period (PP) and Switching Value to check their sensitivity.The results showed R2R business is feasible for non-financially, technical-technological and financial aspects. Technology has evolved to produce various qualities (premium or medium) after the quality of raw materials (low quality or off-grade rice) using profit optimization. Value of the financial parameters was NPV of Rp 137 billion, Net B/C of 5.80, IRR of 84.27 percent and PP of 2.18 years at capacity of 19,800 tons/year with total investment of Rp 30 billion (Rp 13,500/USD). The switching value analysis showed that a decrease in product prices is sensitively influencing the financial feasibility. To strengthen cooperation that enhancing mutually beneficial relationship, R2R assists equipment investment in and buy raw material from SRM at a rational agreed price.
Labelling of rice seedlings and rice plants with 32P

International Nuclear Information System (INIS)

Achmad Nasroh, K.

1989-01-01

Labelling of rice seedlings and rice plants with 32 P. Labelled rice seedlings can be used to tag insect pests that feed on. Radioactivity counting of 32 P in the endosperm and in the shoot of rice seeds that soaked for 72 hours in KH 2 32 PO 4 solution of 1 μCi/ml were 29,300 and 9,500 cpm respectively. When these labelled seedlings were grown in unlabelled medium the radioactivity in the shoot increased. It was due to the 32 P that was translocated to the shoot from the endosperm. The 32 P translocation reached maximum about one week after the seedling were grown in the unlabelled medium. Labelled seedlings could also be produced by growing 5, 10 and 15 days old seedlings hydroponically in Kimura B solution containing 32 P. Ten days after growing, the radioactivity concentration of the seedlings stem reached about 115,000; 85,000 and 170,000 cpm/mg dry weight for the 5, 10 and 15 days old seedlings respectively. For the implementation of this method, 20 ml labelled Kimura B was needed for labelling of one seedling. The seedlings should be prepared in tap water. During the growth the 32 P in the labelled seedlings was distributed throughout the plant, so that new leaves and tillers became also radioactive. (author). 5 refs
Development of silica RO membranes

International Nuclear Information System (INIS)

Ikeda, Ayumi; Kawamoto, Takashi; Matsuyama, Emi; Utsumi, Keisuke; Nomura, Mikihiro; Sugimoto, Masaki; Yoshikawa, Masato

2012-01-01

Silica based membranes have been developed by using a counter diffusion CVD method. Effects of alkyl groups in the silica precursors and deposition temperatures had investigated in order to control pore sizes of the silica membranes. In this study, this type of a silica membrane was applied for RO separation. Effects of silica sources, deposition temperatures and post treatments had been investigated. Tetramethoxysilane (TMOS), Ethyltrimethoxysilane (ETMOS) and Phenyltrimethoxysilane (PhTMOS) were used as silica precursors. A counter diffusion CVD method was carried out for 90 min at 270 - 600degC on γ-alumina capillary substrates (effective length: 50 mm, φ: 4 nm: NOK Co.). O 3 or O 2 was introduced into the inside of the substrate at the O 2 rate of 0.2 L min -1 . Ion beam irradiation was carried out for a post treatment using Os at 490 MeV for 1.0 x 10 10 ions cm -2 or 3.0 x 10 10 ions cm -2 . Single gas permeance was measured by using H 2 , N 2 and SF 6 . RO tests were employed at 3.0 or 5.4 MPa for 100 mg L -1 of feed NaCl solution. First, effects of the silica sources were investigated. The total fluxes increased by increasing N 2 permeance through the silica membrane deposited by ETMOS. The maximum NaCl rejection was 28.2% at 12.2 kg m -2 h -1 of the total flux through the membrane deposited at 270degC. N 2 permeance was 9.6 x 10 -9 mol m -2 s -1 Pa -1 . While, total fluxes through the membrane deposited by using PhTMOS were smaller than those through the ETMOS membranes. The phenyl groups for the PhTMOS membrane must be important for the hydrophobic properties through the membrane. Next, effects of ion beam irradiation were tested for the TMOS membranes. Water is difficult to permeate through the TMOS membranes due to the low N 2 permeance through the membrane (3.1 x 10 -11 mol m -2 s -1 Pa -1 ). N 2 permeance increased to 7.3 x 10 -9 mol m -2 s -1 Pa -1 by the irradiation. Irradiation amounts had little effects on N 2 permeance. However, NaCl rejections
Molecular Dynamics Simulations of Water Droplets On Hydrophilic Silica Surfaces

DEFF Research Database (Denmark)

Zambrano, Harvey A; Walther, Jens Honore; Jaffe, Richard L.

2009-01-01

and DNA microarrays technologies.Although extensive experimental, theoretical and computational work has been devoted to study the nature of the interaction between silica and water, at the molecular level a complete understanding of silica-water systems has not been reached. Contact angle computations...... dynamics (MD) simulations of a hydrophilic air-water-silica system using the MD package FASTTUBE. We employ quantum chemistry calculation to obtain air-silica interaction parameters for the simulations. Our simulations are based in the following force fields: i) The silica-silica interaction is based...... of water droplets on silica surfaces offers a useful fundamental and quantitative measurement in order to study chemical and physical properties of water-silica systems. For hydrophobic systems the static and dynamic properties of the fluid-solid interface are influenced by the presence of air. Hence...
Silica scintillating materials prepared by sol-gel methods

International Nuclear Information System (INIS)

Werst, D.W.; Sauer, M.C. Jr.; Cromack, K.R.; Lin, Y.; Tartakovsky, E.A.; Trifunac, A.D.

1993-01-01

Silica was investigated as a rad-hard alternative to organic polymer hosts for organic scintillators. Silica sol-gels were prepared by hydrolysis of tetramethoxysilane in alcohol solutions. organic dyes were incorporated into the gels by dissolving in methanol at the sol stage of gel formation. The silica sol-gel matrix is very rad-hard. The radiation stability of silica scintillators prepared by this method is dye-limited. Transient radioluminescence was measured following excitation with 30 ps pulses of 20 MeV electrons
Water Footprint Analysis of Paddy Rice and the Nexus of Water-Land-Rice in Taiwan: 2005-2014

Science.gov (United States)

Wu, T. C.

2018-05-01

This paper explores the water footprint (WF) of paddy rice and the nexus of water-land-food (rice) in Taiwan. The research results indicate that the average annual rice WF for the years 2005-2014 was about 7,580 m3/ton, of which 80% was blue, 17% was green, and 3% was grey. This average annual footprint was about 5.7 times larger than the 2000-2004 average annual WF of rice for countries around the globe of 1325 m3/ton, of which 48% was green, 44% was blue, and 8% was grey. The blue WF is the most important source of water for rice production in Taiwan. The water consumption of the second crop is higher than that of the first crop. The water use efficiency in the southern region of Taiwan is the best, while the northern part of Taiwan exhibits relatively high inefficiency. The rates of change in cultivated land and rice production in Taiwan are decreasing in a stable manner. However, the annual rate of change in the rice WF is unstable. The nexus of land, water, and food should be taken into consideration to protect water availability, maintain agricultural production, and avoid land degradation. The results could offer useful information for agriculture policy and water resource management.
Influence of organic solvents on interfacial water at surfaces of silica gel and partially silylated fumed silica

Energy Technology Data Exchange (ETDEWEB)

Turov, V.V.; Gun' ko, V.M.; Tsapko, M.D.; Bogatyrev, V.M.; Skubiszewska-Zieba, J.; Leboda, R.; Ryczkowski, J

2004-05-15

The effects of organic solvents (dimethylsulfoxide-d{sub 6} (DMSO-d{sub 6}), chloroform-d, acetone-d{sub 6}, and acetonitrile-d{sub 3}) on the properties of interfacial water at surfaces of silica gel Si-40 and partially silylated fumed silica A-380 were studied by means of the {sup 1}H NMR spectroscopy with freezing-out of adsorbed water at 180silicas and quantum chemical calculations of the chemical shifts {delta}{sub H} and solvent effects. DMSO-d{sub 6} and acetonitrile-d{sub 3} are poorly miscible with water in silica gel pores in contrast to the bulk liquids. DMSO-d{sub 6} and chloroform-d affect the structure of the interfacial water weaker than acetone-d{sub 6} and acetonitrile-d{sub 3} at amounts of liquids greater than the pore volume. Acetone-d{sub 6} and acetonitrile-d{sub 3} can displace water from pores under this condition. The chemical shift of protons in water adsorbed on silica gel is 3.5-6.5 ppm, which corresponds to the formation of two to four hydrogen bonds per molecule. Water adsorbed on partially silylated fumed silica has two {sup 1}H NMR signals at 5 and 1.1-1.7 ppm related to different structures (droplets and small clusters) of the interfacial water.
Effect of vanadium application on the paddy rice

Energy Technology Data Exchange (ETDEWEB)

Chiu, T F

1953-01-01

The height, the root length and the weight of rice seedlings were increased by the application of ammonium vanadate. The nitrogen contents of seedlings were generally increased in proportion to the amounts of vanadate applied. Carbon contents of seedlings, however, show little difference. The best result was obtained when V/sub 2/O/sub 3/ 150 ppm was applied, but more than 500 ppm was toxic to rice seedlings, and at 1000 ppm all rice seedlings were killed. N, P, and K fertilizers were added to the rice after transplantation from the nursery, but vanadium was omitted. Little difference was found in growth and yield of the rice plants. Vanadium absorbed by younger rice seedlings has little influence on the latter growth and yields of rice plants.
Development and characterization of emulsions containing purple rice bran and brown rice oils

Science.gov (United States)

The aims of this study were to characterize purple rice bran oil (PRBO) as extracted from the bran, and to produce and characterize a nano-emulsion containing purple rice bran oil. An emulsion was prepared using PRBO (10%), sodium caseinate (5%) and water (85%). The mixture was sonicated followed ...
The economic power of the Golden Rice opposition

NARCIS (Netherlands)

Wesseler, J.H.H.; Zilberman, D.

2014-01-01

Vitamin A enriched rice (Golden Rice) is a cost-efficient solution that can substantially reduce health costs. Despite Golden Rice being available since early 2000, this rice has not been introduced in any country. Governments must perceive additional costs that overcompensate the benefits of the
Surface characterization of polyethylene terephthalate/silica nanocomposites

Energy Technology Data Exchange (ETDEWEB)

Parvinzadeh, Mazeyar, E-mail: mparvinzadeh@gmail.com [Department of Textile, Islamic Azad University, Science and Research Branch, Tehran (Iran, Islamic Republic of); Moradian, Siamak [Department of Polymer and Color Engineering, Amirkabir University of Technology, P.O. Box 15875-4413, Tehran (Iran, Islamic Republic of); Rashidi, Abosaeed [Department of Textile, Islamic Azad University, Science and Research Branch, Tehran (Iran, Islamic Republic of); Yazdanshenas, Mohamad-Esmail [Department of Textile, Islamic Azad University, Yazd Branch, Yazd (Iran, Islamic Republic of)

2010-02-15

Poly(ethylene terephthalate) (PET) based nanocomposites containing hydrophilic (i.e. Aerosil 200 or Aerosil TT 600) or hydrophobic (i.e. Aerosil R 972) nano-silica were prepared by melt compounding. Influence of nano-silica type on surface properties of the resultant nanocomposites was investigated by the use of Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), contact angle measurement (CAM), scanning electron microscopy (SEM) and reflectance spectroscopy (RS). The possible interaction between nano-silica particles and PET functional groups at bulk and surface were elucidated by transmission FTIR and FTIR-ATR spectroscopy, respectively. AFM studies of the resultant nanocomposites showed increased surface roughness compared to pure PET. Contact angle measurements of the resultant PET composites demonstrated that the wettability of such composites depends on surface treatment of the particular nano-silica particles used. SEM images illustrated that hydrophilic nano-silica particles tended to migrate to the surface of the PET matrix.

New insight into silica deposition in horsetail (Equisetum arvense

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Exley Christopher

2011-07-01

Full Text Available Abstract Background The horsetails (Equisetum sp are known biosilicifiers though the mechanism underlying silica deposition in these plants remains largely unknown. Tissue extracts from horsetails grown hydroponically and also collected from the wild were acid-digested in a microwave oven and their silica 'skeletons' visualised using the fluor, PDMPO, and fluorescence microscopy. Results Silica deposits were observed in all plant regions from the rhizome through to the stem, leaf and spores. Numerous structures were silicified including cell walls, cell plates, plasmodesmata, and guard cells and stomata at varying stages of differentiation. All of the major sites of silica deposition in horsetail mimicked sites and structures where the hemicellulose, callose is known to be found and these serendipitous observations of the coincidence of silica and callose raised the possibility that callose might be templating silica deposition in horsetail. Hydroponic culture of horsetail in the absence of silicic acid resulted in normal healthy plants which, following acid digestion, showed no deposition of silica anywhere in their tissues. To test the hypothesis that callose might be templating silica deposition in horsetail commercially available callose was mixed with undersaturated and saturated solutions of silicic acid and the formation of silica was demonstrated by fluorimetry and fluorescence microscopy. Conclusions The initiation of silica formation by callose is the first example whereby any biomolecule has been shown to induce, as compared to catalyse, the formation of silica in an undersaturated solution of silicic acid. This novel discovery allowed us to speculate that callose and its associated biochemical machinery could be a missing link in our understanding of biosilicification.
Functionalized mesoporous silica materials for molsidomine adsorption: Thermodynamic study

Energy Technology Data Exchange (ETDEWEB)

Alyoshina, Nonna A.; Parfenyuk, Elena V., E-mail: evp@iscras.ru

2013-09-15

A series of unmodified and organically modified mesoporous silica materials was prepared. The unmodified mesoporous silica was synthesized via sol–gel synthesis in the presence of D-glucose as pore-forming agent. The functionalized by phenyl, aminopropyl and mercaptopropyl groups silica materials were prepared via grafting. The fabricated adsorbent materials were characterized by Fourier transform infrared spectroscopy (FTIR) analysis, N{sub 2} adsorption/desorption and elemental analysis methods. Then their adsorption properties for mesoionic dug molsidomine were investigated at 290–313 K and physiological pH value. Thermodynamic parameters of molsidomine adsorption on the synthesized materials have been calculated. The obtained results showed that the adsorption process of molsidomine on the phenyl modified silica is the most quantitatively and energetically favorable. The unmodified and mercaptopropyl modified silica materials exhibit significantly higher adsorption capacities and energies for molsidomine than the aminopropyl modified sample. The effects are discussed from the viewpoint of nature of specific interactions responsible for the adsorption. - Graphical abstract: Comparative analysis of the thermodynamic characteristics of molsidomine adsorption showed that the adsorption process on mesoporous silica materials is controlled by chemical nature of surface functional groups. Molsidomine adsorption on the phenyl modified silica is the most quantitatively and energetically favorable. Taking into account ambiguous nature of mesoionic compounds, it was found that molsidomine is rather aromatic than dipolar. Display Omitted - Highlights: • Unmodified and organically modified mesoporous silica materials were prepared. • Molsidomine adsorption on the silica materials was studied. • Phenyl modified silica shows the highest adsorption capacity and favorable energy. • Molsidomine exhibits the lowest affinity to aminopropyl modified silica.
RESTRUKTURISASI MENIR MENJADI BERAS BERKALSIUM TINGGI DENGAN METODE EKSTRUSI Restructured Fine Grain Rice to High Calcium Rice by Extrusion Method

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Chatarina Wariyah

2012-05-01

Full Text Available Indonesian calcium intake is still low. So, calcium fortification in such as rice is important. Rice fortification by extru- sion method was conducted by mixing rice flour with fortificant solution, molding and drying. The rice that was resulted from this process is called ultra rice. Menir (finely ground grain rice will be used as raw material of ultra rice. The purposed of this research was to produce high calcium extrusion rice or ultra rice with physical, organoleptic properties and cooking quality as normal rice. The specific purposes were to evaluate the effect of the type and amount of binder(gluten and tapioca on the characteristics of ultra rice, to determine type and amount of binder that resulted high cal- cium ultra rice with high acceptability. The result showed that high calcium ultra rice with tapioca as binder had colour,texture and organoleptic properties as normal rice. The ultra rice texture tended harder than IR-64, but cooked-ultra ricewas softer. The colour of ultra rice with tapioca as binder was similar with IR-64, but ultra rice with gluten as binderwas more yellowness. The cooking quality of ultra rice was less acceptable than IR-64. The high acceptability of ultra rice was made with 4 % tapioca as binder, and the characterictics of this ultra rice were : hardness 140.43N, deforma- tion 63.70 %, the colour with lightness (L 71.08, yellowness (b 11.00, redness (a -0.27 and good cooking quality. ABSTRAK Angka kecukupan asupan kalsium masyarakat Indonesia saat ini masih rendah. Untuk itu perlu dilakukan fortifikasi pada pangan yang umum dikonsumsi masyarakat luas seperti beras. Salah satu cara fortifikasi beras adalah dengan metode ekstrusi yaitu mencampur larutan fortifikan dengan tepung beras, kemudian dicetak dan dikeringkan. Berasyang dihasilkan sering disebut sebagai beras ultra. Untuk meningkatkan kemanfaatan hasil samping penggilingan padi,maka digunakan menir sebagai bahan baku beras ultra
Preparation of an In-House Reference Material Containing Fumonisins in Thai Rice and Matrix Extension of the Analytical Method for Japanese Rice

Science.gov (United States)

Awaludin, Norhafniza; Nagata, Reiko; Kawasaki, Tomomi; Kushiro, Masayo

2009-01-01

Mycotoxin contamination in rice is less reported, compared to that in wheat or maize, however, some Fusarium fungi occasionally infect rice in the paddy field. Fumonisins are mycotoxins mainly produced by Fusarium verticillioides, which often ruins maize. Rice adherent fungus Gibberella fujikuroi is taxonomically near to F. verticillioides, and there are sporadic reports of fumonisin contamination in rice from Asia, Europe and the United States. Therefore, there exists the potential risk of fumonisin contamination in rice as well as the need for the validated analytical method for fumonisins in rice. Although both natural and spiked reference materials are available for some Fusarium mycotoxins in matrices of wheat and maize, there are no reference materials for Fusarium mycotoxins in rice. In this study, we have developed a method for the preparation of a reference material containing fumonisins in Thai rice. A ShakeMaster grinding machine was used for the preparation of a mixed material of blank Thai rice and F. verticillioides-infected Thai rice. The homogeneity of the mixed material was confirmed by one-way analysis of variance, which led this material to serve as an in-house reference material. Using this reference material, several procedures to extract fumonisins from Thai rice were compared. Accordingly, we proved the applicability of an effective extraction procedure for the determination of fumonisins in Japanese rice. PMID:22069540
Effects of white rice, brown rice and germinated brown rice on antioxidant status of type 2 diabetic rats.

Science.gov (United States)

Imam, Mustapha Umar; Musa, Siti Nor Asma; Azmi, Nur Hanisah; Ismail, Maznah

2012-10-10

Oxidative stress is implicated in the pathogenesis of diabetic complications, and can be increased by diet like white rice (WR). Though brown rice (BR) and germinated brown rice (GBR) have high antioxidant potentials as a result of their bioactive compounds, reports of their effects on oxidative stress-related conditions such as type 2 diabetes are lacking. We hypothesized therefore that if BR and GBR were to improve antioxidant status, they would be better for rice consuming populations instead of the commonly consumed WR that is known to promote oxidative stress. This will then provide further reasons why less consumption of WR should be encouraged. We studied the effects of GBR on antioxidant status in type 2 diabetic rats, induced using a high-fat diet and streptozotocin injection, and also evaluated the effects of WR, BR and GBR on catalase and superoxide dismutase genes. As dietary components, BR and GBR improved glycemia and kidney hydroxyl radical scavenging activities, and prevented the deterioration of total antioxidant status in type 2 diabetic rats. Similarly, GBR preserved liver enzymes, as well as serum creatinine. There seem to be evidence that upregulation of superoxide dismutase gene may likely be an underlying mechanism for antioxidant effects of BR and GBR. Our results provide insight into the effects of different rice types on antioxidant status in type 2 diabetes. The results also suggest that WR consumption, contrary to BR and GBR, may worsen antioxidant status that may lead to more damage by free radicals. From the data so far, the antioxidant effects of BR and GBR are worth studying further especially on a long term to determine their effects on development of oxidative stress-related problems, which WR consumption predisposes to.
Effects of White Rice, Brown Rice and Germinated Brown Rice on Antioxidant Status of Type 2 Diabetic Rats

Directory of Open Access Journals (Sweden)

Maznah Ismail

2012-10-01

Full Text Available Oxidative stress is implicated in the pathogenesis of diabetic complications, and can be increased by diet like white rice (WR. Though brown rice (BR and germinated brown rice (GBR have high antioxidant potentials as a result of their bioactive compounds, reports of their effects on oxidative stress-related conditions such as type 2 diabetes are lacking. We hypothesized therefore that if BR and GBR were to improve antioxidant status, they would be better for rice consuming populations instead of the commonly consumed WR that is known to promote oxidative stress. This will then provide further reasons why less consumption of WR should be encouraged. We studied the effects of GBR on antioxidant status in type 2 diabetic rats, induced using a high-fat diet and streptozotocin injection, and also evaluated the effects of WR, BR and GBR on catalase and superoxide dismutase genes. As dietary components, BR and GBR improved glycemia and kidney hydroxyl radical scavenging activities, and prevented the deterioration of total antioxidant status in type 2 diabetic rats. Similarly, GBR preserved liver enzymes, as well as serum creatinine. There seem to be evidence that upregulation of superoxide dismutase gene may likely be an underlying mechanism for antioxidant effects of BR and GBR. Our results provide insight into the effects of different rice types on antioxidant status in type 2 diabetes. The results also suggest that WR consumption, contrary to BR and GBR, may worsen antioxidant status that may lead to more damage by free radicals. From the data so far, the antioxidant effects of BR and GBR are worth studying further especially on a long term to determine their effects on development of oxidative stress-related problems, which WR consumption predisposes to.
A spectral analysis of rice grains

International Nuclear Information System (INIS)

McIlvaine, M.S.; Cua, F.T.; Navarro, E.F.

1976-06-01

With the advent of extensive nuclear testing and the development and use of highly potent pesticides and fertilizers, the hazardous threats of radioactive contamination due to fallout and to the absorption of pesticide residues have been given due consideration. Among the many forms of life exposed to these threats are food crops and among these is rice. Several rice grain samples - Japanese rice samples ''A'' and ''B'' submitted by the National Grains Authority (NGA) for analysis, random samples of rice being sold to the public at local markets, and ''black rice'' which were picked from along the shores of a Mindoro town were subjected to spectral analysis. Results revealed the presence of trace elements normally found in plants, such as; K-42, I-124, Cl-38, Na-24, Br-82, and Mn-56. No mercury was detected in the sample specimen analyzed
Sports Injuries in Brazilian Blind Footballers

OpenAIRE

Silva, MPME; Morato, MP; Bilzon, JLJ; Duarte, E

2013-01-01

The purpose of this study was to assess the characteristics and prevalence of sports-related injuries in visually disabled athletes of the Brazilian football 5-a-side team. The participants were 13 male athletes, all classified as B1 visual class, members of the Brazilian team, who played in five consecutive international competitions. Data were collected using the Brazilian Paralympic Committee and the Brazilian Confederation of Sports for the Blind report form. From the total of 13 athletes...
Complementarity of Two Rice Mapping Approaches: Characterizing Strata Mapped by Hypertemporal MODIS and Rice Paddy Identification Using Multitemporal SAR

Directory of Open Access Journals (Sweden)

Sonia Asilo

2014-12-01

Full Text Available Different rice crop information can be derived from different remote sensing sources to provide information for decision making and policies related to agricultural production and food security. The objective of this study is to generate complementary and comprehensive rice crop information from hypertemporal optical and multitemporal high-resolution SAR imagery. We demonstrate the use of MODIS data for rice-based system characterization and X-band SAR data from TerraSAR-X and CosmoSkyMed for the identification and detailed mapping of rice areas and flooding/transplanting dates. MODIS was classified using ISODATA to generate cropping calendar, cropping intensity, cropping pattern and rice ecosystem information. Season and location specific thresholds from field observations were used to generate detailed maps of rice areas and flooding/transplanting dates from the SAR data. Error matrices were used for the accuracy assessment of the MODIS-derived rice characteristics map and the SAR-derived detailed rice area map, while Root Mean Square Error (RMSE and linear correlation were used to assess the TSX-derived flooding/transplanting dates. Results showed that multitemporal high spatial resolution SAR data is effective for mapping rice areas and flooding/transplanting dates with an overall accuracy of 90% and a kappa of 0.72 and that hypertemporal moderate-resolution optical imagery is effective for the basic characterization of rice areas with an overall accuracy that ranged from 62% to 87% and a kappa of 0.52 to 0.72. This study has also provided the first assessment of the temporal variation in the backscatter of rice from CSK and TSX using large incidence angles covering all rice crop stages from pre-season until harvest. This complementarity in optical and SAR data can be further exploited in the near future with the increased availability of space-borne optical and SAR sensors. This new information can help improve the identification of rice
Rice methylmercury exposure and mitigation: a comprehensive review

Science.gov (United States)

Rothenberg, Sarah E.; Windham-Myers, Lisamarie; Creswell, Joel E.

2014-01-01

Rice cultivation practices from field preparation to post-harvest transform rice paddies into hot spots for microbial mercury methylation, converting less-toxic inorganic mercury to more-toxic methylmercury, which is likely translocated to rice grain. This review includes 51 studies reporting rice total mercury and/or methylmercury concentrations, based on rice (Orzya sativa) cultivated or purchased in 15 countries. Not surprisingly, both rice total mercury and methylmercury levels were significantly higher in polluted sites compared to non-polluted sites (Wilcoxon rank sum, price percent methylmercury (of total mercury) did not differ statistically between polluted and non-polluted sites (Wilcoxon rank sum, p=0.35), suggesting comparable mercury methylation rates in paddy soil across these sites and/or similar accumulation of mercury species for these rice cultivars. Studies characterizing the effects of rice cultivation under more aerobic conditions were reviewed to determine the mitigation potential of this practice. Rice management practices utilizing alternating wetting and drying (instead of continuous flooding) caused soil methylmercury levels to spike, resulting in a strong methylmercury pulse after fields were dried and reflooded; however, it is uncertain whether this led to increased translocation of methylmercury from paddy soil to rice grain. Due to the potential health risks, it is advisable to investigate this issue further, and to develop separate water management strategies for mercury polluted and non-polluted sites, in order to minimize methylmercury exposure through rice ingestion.
Effects of fish and prawn culture on physico-chemical parameters of water and rice yield in rice fields

OpenAIRE

Razzak, M.A.; Nahar, A.; Mirhaj, M.; Becker, K.; Dewan, S.

2009-01-01

An experiment was conducted with five treatments i.e. rice combined with fish having regular urea fertilization (T1), rice combined with prawn having regular urea fertilization (T2), rice combined with fish with supplementary feeding (T3), rice combined with prawn with supplementary feeding (T4) and without fish and prawn (T5) was kept as control. The dissolved oxygen values obtained in treatments with fish both in morning and afternoon were lower than the values of prawn containing treatment...
Modified silica sol coatings for surface enhancement of leather.

Science.gov (United States)

Mahltig, Boris; Vossebein, Lutz; Ehrmann, Andrea; Cheval, Nicolas; Fahmi, Amir

2012-06-01

The presented study reports on differently modified silica sols for coating applications on leather. Silica sols are prepared by acidic hydrolysis of tetraethoxysilane and modified by silane compounds with fluorinated and non-fluorinated alkylgroups. In contrast to many earlier investigations regarding sol-gel applications on leather, no acrylic resin is used together with the silica sols when applying on leather. The modified silica particles are supposed to aggregate after application, forming thus a modified silica coating on the leather substrate. Scanning electron microscopy investigation shows that the applied silica coatings do not fill up or close the pores of the leather substrate. However, even if the pores of the leather are not sealed by this sol-gel coating, an improvement of the water repellent and oil repellent properties of the leather substrates are observed. These improved properties of leather by application of modified silica sols can provide the opportunity to develop sol-gel products for leather materials present in daily life.
Niobia-silica and silica membranes for gas separation

NARCIS (Netherlands)

Boffa, V.

2008-01-01

This thesis describes the development of ceramic membranes suitable for hydrogen separation and CO2 recovery from gaseous streams. The research work was focused on the three different parts of which gas selective ceramic membranes are composed, i.e., the microporous gas selective silica layer, the
Upland rice yield as affected by Brachiaria coverage management

Directory of Open Access Journals (Sweden)

Adriano S. Nascente

2015-01-01

Full Text Available An important point in no-tillage system is the time between cover crop glyphosate desiccation and rice sowing. This study aimed to verify the effect of Brachiaria ruziziensis management time before rice sowing on rice yield and its components. The experiment was conducted under greenhouse conditions and consisted of four types of B. ruziziensis management: with Brachiaria and with herbicide (WBWH, without Brachiaria shoots and with herbicide (NBWH, without Brachiaria shoots and without herbicide (NBNH, and with Brachiaria and without herbicide (WBNH, at four times: 30, 20, 10, and 0 days, preceding the rice sowing. The amount of B. ruziziensis dry matter increased as the management was done closer to the rice sowing date. The WBWH and WBNH managements (this one causes the lowest rice grain yield must be done 30 days before rice sowing; while NBWH management must be done ten or more days before rice sowing. On the other hand, NBNH management (this one favors the best rice grain yield can be done until rice sowing day. Despite some reduction in rice yield caused by the B. ruziziensis management, when it was done at the proper time the rice grain yield was similar to the control (without Brachiaria sowing and without herbicide application.
Harvest season and head rice yield of upland rice cultivars submitted to parboiling

Directory of Open Access Journals (Sweden)

Diva Mendonça Garcia

2012-11-01

Full Text Available Normal 0 21 false false false PT-BR X-NONE X-NONE This work aimed to evaluate the effects of parboiling on the yield of upland rice cultivars harvested at different times. The cultivars were BRS Primavera and BRS Sertaneja, harvested at 30 and 47 days after flowering (DAF. For parboiling, samples were soaked in water bath at 65 °C in grain: water ratio of 1:1.6 in order to reach 25% and 30% moisture, and then were autoclaved for 10 minutes at 120 °C and 1.1 kg/cm2 of pressure. After drying up to 13% moisture in a greenhouse with forced air at 40 °C, samples were benefited, followed by separation using the trieur equipment and weighing to obtain the head rice yield. The results showed a higher yield for head rice harvested at 30 DAF than at 47 DAF (BRS Primavera 63.2 and 38.7%; BRS Sertaneja 68.5 and 55.7%, respectively. Parboiling increased the head rice yield, regardless of harvest season, but partly reflected the potential of the cultivar origin: BRS Primavera 70.06%, BRS Sertaneja 74.94%. It is concluded that the harvest season is one of the factors that most influence the quality of industrial rice and the effect of parboiling also depends on the potential of the material source.
Stimulate The Growth of Rice Using Endophytic Bacteria from Lowland Rice Plant Tissue

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Nuni Gofar

2015-07-01

Full Text Available Exploration and selection of endophytic bacteria from healthy food crops grown in lowland ecosystem is important to be conducted in order to get growth-stimulating endophytic bacteria at soil with low fertility level so that capable to optimize initial growth of food crops and subsequently can increase productivity level of lowland soil.The research objective was to isolate and to test the IAA-producing endophytic bacteria isolate in stimulating the rice crop growth at lowland area. Endophytic bacteria are isolated from tissues of rice, corn and peanut crops which grown at shallow swamp land in Ogan Ilir and Ogan Komering Ilir Districts, South Sumatra, Indonesia. There was nine isolates of nitrogen-fixer endophytic bacteria that capable to contribute IAA phytohormone into their growth media. The P31 isolate from rice crop tisssue of 2 months old produce the best rice sprouts than other isolates. This isolate can contribute of about 10 mg kg-1 IAA to its growth medium and increase the crowns dry weight and the roots dry weight respectively with magnitudes of 133% and 225% compared to control treatment. Concentration and absorbtion of N for rice crops innoculated with P31 isolates had increased by 169% and 400%, recpectively. The P31 isolates had been identified as Burkholderia pseudomallei (also known as Pseudomonas pseudomallei.
Sonochemical synthesis of silica particles and their size control

Energy Technology Data Exchange (ETDEWEB)

Kim, Hwa-Min [Advanced Materials and Chemical Engineering, Catholic University of Daegu, Gyeongbuk 38430 (Korea, Republic of); Lee, Chang-Hyun [Electronic and Electrical Engineering, Catholic University of Daegu, Gyeongbuk 38430 (Korea, Republic of); Kim, Bonghwan, E-mail: bhkim@cu.ac.kr [Electronic and Electrical Engineering, Catholic University of Daegu, Gyeongbuk 38430 (Korea, Republic of)

2016-09-01

Graphical abstract: - Highlights: • Silica particles were easily prepared by an ultrasound-assisted sol–gel method. • The particle size was controlled by the ammonium hydroxide/water molar ratio. • The size-controlled diameter of silica particles ranged from 40 to 400 nm. • The particles were formed in a relatively short reaction time. - Abstract: Using an ultrasound-assisted sol–gel method, we successfully synthesized very uniformly shaped, monodisperse, and size-controlled spherical silica particles from a mixture of ethanol, water, and tetraethyl orthosilicate in the presence of ammonia as catalyst, at room temperature. The diameters of the silica particles were distributed in the range from 40 to 400 nm; their morphology was well characterized by scanning electron microscopy. The silica particle size could be adjusted by choosing suitable concentrations of ammonium hydroxide and water, which in turn determined the nucleation and growth rates of the particles during the reaction. This sonochemical-based silica synthesis offers an alternative way to produce spherical silica particles in a relatively short reaction time. Thus, we suggest that this simple, low-cost, and efficient method of preparing uniform silica particles of various sizes will have practical and wide-ranging industrial applicability.
Study on residues of 14C-Fenitrothion in a model rice-fish ecosystem and in a field rice-fish ecosystem

International Nuclear Information System (INIS)

Zhang Zhongliang; Wang Huaxin; Guo Dazhi; Chen Zhiyu; Wu Suchueng

1993-01-01

Residues of 14 C-fenitrothion in a model rice-fish ecosystem and field rice-fish ecosystem were studied. When equal amounts of the pesticide were applied, the extractable residues in brown rice (equivalent to 34.3±1.9 μg/kg fenitrothion) and rice stems and leaves (20.9±1.5 μg/kg) of the model rice-fish ecosystem were 10-15 times higher than that of the field rice-fish ecosystem (4.48±0.13 μg/kg and 1.27±0.34 μg/kg respectively). Residues in upper part of the soil (6.50±0.1--8.10±0.2 μg/kg) and lower part of the soil (1.30±0.1--1.50±0.1 μg/kg) of the model rice-fish ecosystem were 10-40 times higher than that of the field rice-fish ecosystem (0.17±0.01 μg/kg). The extractable residues in paddy water of the model ecosystem (0.30 ± 0.01 μg/kg) were similar to that of the field ecosystem (0.20±0.02 μg/kg). When the fenitrothion was sprayed on the rice plants, residues in brown rice, fish body, soil and paddy water were lower than those when the pesticide was spread on the surface of the soil. (author). 4 refs, 2 tabs
Effect of the Silica Content of Diatoms on Protozoan Grazing

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Shuwen Zhang

2017-06-01

Full Text Available This study examined the effect that silica content in diatom cells has on the behavior of protists. The diatoms Thalassiosira weissflogii and T. pseudonana were cultured in high or low light conditions to achieve low and high silica contents, respectively. These cells were then fed to a heterotrophic dinoflagellate Noctiluca scintillans and a ciliate Euplotes sp. in single and mixed diet experiments. Our results showed that in general, N. scintillans and Euplotes sp. both preferentially ingested the diatoms with a low silica content rather than those with a high silica content. However, Euplotes sp. seemed to be less influenced by the silica content than was N. scintillans. In the latter case, the clearance and ingestion rate of the low silica diatoms were significantly higher, both in the short (6-h and long (1-d duration grazing experiments. Our results also showed that N. scintillans required more time to digest the high silica-containing cells. As the high silica diatoms are harder to digest, this might explain why N. scintillans exhibits a strong preference for the low silica prey. Thus, the presence of high silica diatoms might limit the ability of the dinoflagellate to feed. Our findings suggest that the silica content of diatoms affects their palatability and digestibility and, consequently, the grazing activity and selectivity of protozoan grazers.
Vinegar rice (Oryza sativa L.) produced by a submerged fermentation process from alcoholic fermented rice

OpenAIRE

Spinosa,Wilma Aparecida; Santos Júnior,Vitório dos; Galvan,Diego; Fiorio,Jhonatan Luiz; Gomez,Raul Jorge Hernan Castro

2015-01-01

Considering the limited availability of technology for the production of rice vinegar and also due to the potential consumer product market, this study aimed to use alcoholic fermented rice (rice wine (Oryza sativa L.)) for vinegar production. An alcoholic solution with 6.28% (w/v) ethanol was oxidized by a submerged fermentation process to produce vinegar. The process of acetic acid fermentation occurred at 30 ± 0.3°C in a FRINGS® Acetator (Germany) for the production of vineg...

Establishment of a rice-duck integrated farming system and its effects on soil fertility and rice disease control

Science.gov (United States)

Teng, Qing; Hu, Xue-Feng; Cheng, Chang; Luo, Zhi-Qing; Luo, Fan

2015-04-01

Rice-duck integrated farming is an ecological farming system newly established in some areas of southern China . It was reported that the ducks walking around the paddy fields is beneficial to control weed hazards and reduce rice pests and diseases. To study and evaluate the effects of the rice-duck integrated farming on soil fertility and rice disease control, a field experiment of rice cultivation was carried out in the suburb of Shanghai in 2014. It includes a treatment of raising ducks in the fields and a control without ducks. The treatment was implemented by building a duck coop nearby the experimental fields and driving 15 ducks into a plot at daytime since the early stage of rice growth. Each plot is 667 m2 in area. The treatment and control were replicated for three times. No any herbicides, pesticides, fungicides and chemical fertilizers were applied during the experiment to prevent any disturbance to duck growing and rice weed hazards and disease incidences from agrochemicals. The results are as follows: (1) The incidences of rice leaf rollers (Cnaphalocrocis medinalis) and stem borers treated with ducks, 0.45%and 1.18% on average, respectively, are lower than those of the control, 0.74% and 1.44% on average, respectively. At the late stage of rice growth, the incidence of rice sheath blight treated with ducks, 13.15% on average, is significantly lower than that of the control, 16.9% on average; and the incidence of rice planthoppers treated with ducks, 11.3 per hill on average, is also significantly lower than that of the control, 47.4 per hill on average. (2) The number of weeds in the plots treated with ducks, 8.3 per m2 on average, is significantly lower than that of the control, 87.5 m2 on average. (3) Raising ducks in the fields could also enhance soil enzyme activity and nutrient status. At the late stage of rice growth, the activities of urease, phosphatase, sucrase and catalase in the soils treated with ducks are 1.39 times, 1.40 times, 1
Production of glutinous rice flour from broken rice via ultrasonic assisted extraction of amylose.

Science.gov (United States)

Setyawati, Yohana Dwi; Ahsan, Sitti Faika; Ong, Lu Ki; Soetaredjo, Felycia Edi; Ismadji, Suryadi; Ju, Yi-Hsu

2016-07-15

In this study, a modified aqueous leaching method by complex formation of amylose with glycerol was employed for reducing the amylose content of starch in broken white rice to less than 2%, so that the resulting starch can be classified to that of glutinous rice flour. By employing ultrasonication in alkaline condition, extraction of amylose could be performed by washing at lower temperature in shorter time compared to the existing aqueous leaching method. The effects of glycerol concentration, alkali concentration, ultrasonication and treatment time on the amylose content of the treated starch were systematically investigated. Under optimum condition, amylose content of broken white rice starch can be reduced from 27.27% to 1.43% with a yield of 80.42%. The changes in the physicochemical properties of the rice flour before and after treatment were studied. Copyright © 2016 Elsevier Ltd. All rights reserved.
Radiocarbon ages of Sorori ancient rice of Korea

Energy Technology Data Exchange (ETDEWEB)

Kim, Kyeong Ja, E-mail: kjkim@kigam.re.kr [Korea Institute of Geoscience and Mineral Resources, Daejeon (Korea, Republic of); Lee, Yung-Jo; Woo, Jong-Yoon [Institute of Korean Prehistory, Cheongju (Korea, Republic of); Jull, A.J. Timothy [NSF Arizona AMS Laboratory, University of Arizona, Tucson, AZ 85721 (United States)

2013-01-15

Samples of Sorori ancient rice were excavated in 1998 from the Sorori Paleolithic site located at Sorori, Oksan-myeon, Cheong-won County in Chungcheongbuk-do, Korea. We have made new radiocarbon measurements for Sorori samples in 2009 at the NSF Arizona AMS Laboratory. Both ancient rice samples and surrounded peat from the Sorori site were dated. The AMS results confirmed that the ages of the rice and peat soil were 12,520 {+-} 150 and 12,552 {+-} 90 BP, respectively. These radiocarbon ages are consistent with the previously published data of quasi rice measured at Seoul National University and confirm that the Sorori rice is the oldest ancient rice currently reported.
Cropping system diversification for food production in Mindanao rubber plantations: a rice cultivar mixture and rice intercropped with mungbean

Science.gov (United States)

Elazegui, Francisco; Duque, Jo-Anne Lynne Joy E.; Mundt, Christopher C.; Vera Cruz, Casiana M.

2017-01-01

Including food production in non-food systems, such as rubber plantations and biofuel or bioenergy crops, may contribute to household food security. We evaluated the potential for planting rice, mungbean, rice cultivar mixtures, and rice intercropped with mungbean in young rubber plantations in experiments in the Arakan Valley of Mindanao in the Philippines. Rice mixtures consisted of two- or three-row strips of cultivar Dinorado, a cultivar with higher value but lower yield, and high-yielding cultivar UPL Ri-5. Rice and mungbean intercropping treatments consisted of different combinations of two- or three-row strips of rice and mungbean. We used generalized linear mixed models to evaluate the yield of each crop alone and in the mixture or intercropping treatments. We also evaluated a land equivalent ratio for yield, along with weed biomass (where Ageratum conyzoides was particularly abundant), the severity of disease caused by Magnaporthe oryzae and Cochliobolus miyabeanus, and rice bug (Leptocorisa acuta) abundance. We analyzed the yield ranking of each cropping system across site-year combinations to determine mean relative performance and yield stability. When weighted by their relative economic value, UPL Ri-5 had the highest mean performance, but with decreasing performance in low-yielding environments. A rice and mungbean intercropping system had the second highest performance, tied with high-value Dinorado but without decreasing relative performance in low-yielding environments. Rice and mungbean intercropped with rubber have been adopted by farmers in the Arakan Valley. PMID:28194318
Stimulated resonant scattering at stressed fused silica surface

International Nuclear Information System (INIS)

Bouchut, Philippe; Reymermier, Maryse

2015-01-01

The radiative emission in CO 2 laser heated stressed fused silica is radically modified when gold microspheres are on the surface. At high heating rates, the emission dynamics changes from thermoluminescence to stimulated resonant scattering with an emission rate that is increased tenfold and the near infrared (NIR) spectrum is red-shifted. We show that the dynamic tensile stress that rises in heated silica is coupled with a fluctuating electromagnetic field that enables electromagnetic friction between moving OH emitters from silica bulk and NIR resonant scatterers at the silica surface. (paper)
Assessment of reference gene stability in Rice stripe virus and Rice black streaked dwarf virus infection rice by quantitative Real-time PCR.

Science.gov (United States)

Fang, Peng; Lu, Rongfei; Sun, Feng; Lan, Ying; Shen, Wenbiao; Du, Linlin; Zhou, Yijun; Zhou, Tong

2015-10-24

Stably expressed reference gene(s) normalization is important for the understanding of gene expression patterns by quantitative Real-time PCR (RT-qPCR), particularly for Rice stripe virus (RSV) and Rice black streaked dwarf virus (RBSDV) that caused seriously damage on rice plants in China and Southeast Asia. The expression of fourteen common used reference genes of Oryza sativa L. were evaluated by RT-qPCR in RSV and RBSDV infected rice plants. Suitable normalization reference gene(s) were identified by geNorm and NormFinder algorithms. UBQ 10 + GAPDH and UBC + Actin1 were identified as suitable reference genes for RT-qPCR normalization under RSV and RBSDV infection, respectively. When using multiple reference genes, the expression patterns of OsPRIb and OsWRKY, two virus resistance genes, were approximately similar with that reported previously. Comparatively, by using single reference gene (TIP41-Like), a weaker inducible response was observed. We proposed that the combination of two reference genes could obtain more accurate and reliable normalization of RT-qPCR results in RSV- and RBSDV-infected plants. This work therefore sheds light on establishing a standardized RT-qPCR procedure in RSV- and RBSDV-infected rice plants, and might serve as an important point for discovering complex regulatory networks and identifying genes relevant to biological processes or implicated in virus.
Arachidonic acid metabolism in silica-stimulated bovine alveolar macrophages

International Nuclear Information System (INIS)

Englen, M.D.

1989-01-01

The in vitro production of arachidonic acid (AA) metabolites in adherent bovine alveolar macrophages (BAM) incubated with silica was investigated. BAM were pre-labelled with 3 H-AA, and lipid metabolites released into the culture medium were analyzed by high performance liquid chromatography (HPLC). Lactate dehydrogenase (LDH) release was simultaneously assayed to provide an indication of cell injury. Increasing doses of silica selectively stimulated the 5-lipoxygenase pathway of AA metabolism, while cyclooxygenase metabolite output was suppressed. LDH release increased in a linear, dose-dependent fashion over the range of silica doses used. Moreover, within 15 min following addition of a high silica dose, a shift to the production of 5-lipoxygenase metabolites occurred, accompanied by a reduction in cyclooxygenase products. This rapid alteration in AA metabolism preceded cell injury. To examine the relationship between cytotoxicity and AA metabolite release by BAM exposed to silicas with different cytotoxic and fibrogenic activities, BAM were exposed to different doses of DQ-12, Minusil-5, and Sigma silicas, and carbonyl iron beads. The median effective dose (ED 50 ) of each particulate to stimulate the release of AA metabolites and LDH was calculated. The ED 50 values for DQ-12, Minusil-5, and Sigma silica showed that the relative cytotoxicities of the different silicas for BAM corresponded to the relative potencies of the silicas to elicit 5-lipoxygenase metabolites from BAM. These results indicate that the cytotoxic, and presumed fibrogenic potential, of a silica is correlated with the potency to stimulate the release of leukotrienes from AM
Significance of rice sheath photosynthesis: Yield determination by ...

African Journals Online (AJOL)

Using high-yielding hybrid rice Liangyopeijiu (LYP9), its male parent 9311 and hybrid rice Shanyou 63 (SY63) as the experimental materials, the photosynthesis of rice sheath was studied by 14C radio-autography. The results showed that rice sheath could trap sunlight and produce photosynthates, and these ...
Econometric Model of Rice Policy Based On Presidential Instruction

Science.gov (United States)

Abadi Sembiring, Surya; Hutauruk, Julia

2018-01-01

The objective of research is to build an econometric model based on Presidential Instruction rice policy. The data was monthly time series from March 2005 to September 2009. Rice policy model specification using simultaneous equation, consisting of 14 structural equations and four identity equation, which was estimated using Two Stages Least Squares (2SLS) method. The results show that: (1) an increase of government purchasing price of dried harvest paddy has a positive impact on to increase in total rice production and community rice stock, (2) an increase community rice stock lead to decrease the rice imports, (3) an increase of the realization of the distribution of subsidized ZA fertilizers and the realization of the distribution of subsidized NPK fertilizers has a positive impact on to increase in total rice production and community rice stock and to reduce rice imports, (4) the price of the dried harvest paddy is highly responsive to the water content of dried harvest paddy both the short run and long run, (5) the quantity of rice imported is highly responsive to the imported rice price, both short run and long run.
Three-dimensional printing of transparent fused silica glass

Science.gov (United States)

Kotz, Frederik; Arnold, Karl; Bauer, Werner; Schild, Dieter; Keller, Nico; Sachsenheimer, Kai; Nargang, Tobias M.; Richter, Christiane; Helmer, Dorothea; Rapp, Bastian E.

2017-04-01

Glass is one of the most important high-performance materials used for scientific research, in industry and in society, mainly owing to its unmatched optical transparency, outstanding mechanical, chemical and thermal resistance as well as its thermal and electrical insulating properties. However, glasses and especially high-purity glasses such as fused silica glass are notoriously difficult to shape, requiring high-temperature melting and casting processes for macroscopic objects or hazardous chemicals for microscopic features. These drawbacks have made glasses inaccessible to modern manufacturing technologies such as three-dimensional printing (3D printing). Using a casting nanocomposite, here we create transparent fused silica glass components using stereolithography 3D printers at resolutions of a few tens of micrometres. The process uses a photocurable silica nanocomposite that is 3D printed and converted to high-quality fused silica glass via heat treatment. The printed fused silica glass is non-porous, with the optical transparency of commercial fused silica glass, and has a smooth surface with a roughness of a few nanometres. By doping with metal salts, coloured glasses can be created. This work widens the choice of materials for 3D printing, enabling the creation of arbitrary macro- and microstructures in fused silica glass for many applications in both industry and academia.
Combined influence of Bt rice and rice dwarf virus on biological parameters of a non-target herbivore, Nephotettix cincticeps (Uhler) (Hemiptera: Cicadellidae).

Science.gov (United States)

Wang, Qianjin; Han, Naishun; Dang, Cong; Lu, Zengbin; Wang, Fang; Yao, Hongwei; Peng, Yufa; Stanley, David; Ye, Gongyin

2017-01-01

The advent of genetically modified (GM) Bt rice creates the possibility of interactions among Bt crops, crop pathogens and non-target herbivores. In particular, information on how pathogen-infected Bt-expressing plants will influence non-target herbivores is necessary to predict the sustainability of GM cropping systems. Laboratory bioassays were conducted to evaluate the potential combined impacts of rice dwarf virus (RDV) and two Bt rice lines, T1C-19 (Cry1C) and T2A-1 (Cry2A), on non-target green rice leafhopper (GRLH), Nephotettix cincticeps (Uhler) (Hemiptera: Cicadellidae). In the first experiment, GRLHs feeding preference tests on Bt rice lines compared to a parental control rice line, MH63, were conducted. As rice plants were uninfected with RDV, GRLHs generally preferred the control MH63 line over the two Bt lines during the initial 8 h, with no significant preference during the following 64 h. As rice plants were infected with RDV, there were no clear preferences between the Bt rice lines and the control MH63 line. In the second experiment, we assessed the combined influence of RDV-infection status and Bt rice lines on GRLH biological parameters. Egg duration, adult weights, and male adult longevity were significantly affected on RDV-infected Bt rice. Other parameters, egg hatching rate, nymph survival and fecundity were not significantly influenced. We infer that interaction effect among two testing Bt rice lines and RDV will not lead to enlarged pest populations, thus demonstrating that growing these two Bt rice lines will poses negligible risk to GRLH in sustainable rice agroecosystems. Long-term field experiments to monitor the population dynamics of GRLHs at large scale need to be carried out to confirm the current results.
Combined influence of Bt rice and rice dwarf virus on biological parameters of a non-target herbivore, Nephotettix cincticeps (Uhler (Hemiptera: Cicadellidae.

Directory of Open Access Journals (Sweden)

Qianjin Wang

Full Text Available The advent of genetically modified (GM Bt rice creates the possibility of interactions among Bt crops, crop pathogens and non-target herbivores. In particular, information on how pathogen-infected Bt-expressing plants will influence non-target herbivores is necessary to predict the sustainability of GM cropping systems. Laboratory bioassays were conducted to evaluate the potential combined impacts of rice dwarf virus (RDV and two Bt rice lines, T1C-19 (Cry1C and T2A-1 (Cry2A, on non-target green rice leafhopper (GRLH, Nephotettix cincticeps (Uhler (Hemiptera: Cicadellidae. In the first experiment, GRLHs feeding preference tests on Bt rice lines compared to a parental control rice line, MH63, were conducted. As rice plants were uninfected with RDV, GRLHs generally preferred the control MH63 line over the two Bt lines during the initial 8 h, with no significant preference during the following 64 h. As rice plants were infected with RDV, there were no clear preferences between the Bt rice lines and the control MH63 line. In the second experiment, we assessed the combined influence of RDV-infection status and Bt rice lines on GRLH biological parameters. Egg duration, adult weights, and male adult longevity were significantly affected on RDV-infected Bt rice. Other parameters, egg hatching rate, nymph survival and fecundity were not significantly influenced. We infer that interaction effect among two testing Bt rice lines and RDV will not lead to enlarged pest populations, thus demonstrating that growing these two Bt rice lines will poses negligible risk to GRLH in sustainable rice agroecosystems. Long-term field experiments to monitor the population dynamics of GRLHs at large scale need to be carried out to confirm the current results.
Signatures of adaptation in the weedy rice genome

Science.gov (United States)

Weedy rice is a common problem of by product of domestication that has evolved multiple times from cultivated and wild rice relatives. Here we use whole genome sequences to examine the origin and adaptation of the two major US weedy red rice strains, with a comparison to Chinese weedy red rice. We f...
7 CFR 868.301 - Definition of milled rice.

Science.gov (United States)

2010-01-01

... 7 Agriculture 7 2010-01-01 2010-01-01 false Definition of milled rice. 868.301 Section 868.301... FOR CERTAIN AGRICULTURAL COMMODITIES United States Standards for Milled Rice Terms Defined § 868.301 Definition of milled rice. Whole or broken kernels of rice (Oryza sativa L.) from which the hulls and at...
7 CFR 868.201 - Definition of rough rice.

Science.gov (United States)

2010-01-01

... 7 Agriculture 7 2010-01-01 2010-01-01 false Definition of rough rice. 868.201 Section 868.201... FOR CERTAIN AGRICULTURAL COMMODITIES United States Standards for Rough Rice Terms Defined § 868.201 Definition of rough rice. Rice (Oryza sativa L.) which consists of 50 percent or more of paddy kernels (see...
Fermented Brown Rice Flour as Functional Food Ingredient

OpenAIRE

Ilowefah, Muna; Chinma, Chiemela; Bakar, Jamilah; Ghazali, Hasanah; Muhammad, Kharidah; Makeri, Mohammad

2014-01-01

As fermentation could reduce the negative effects of bran on final cereal products, the utilization of whole-cereal flour is recommended, such as brown rice flour as a functional food ingredient. Therefore, this study aimed to investigate the effect of fermented brown rice flour on white rice flour, white rice batter and its steamed bread qualities. Brown rice batter was fermented using commercial baker?s yeast (Eagle brand) according to the optimum conditions for moderate acidity (pH 5.5) to...
Modification of silica surface by gamma ray induced Ad micellar Polymerization

International Nuclear Information System (INIS)

Buathong, Salukjit; Pongprayoon, Thirawudh; Suwanmala, Phiriyatorn

2005-10-01

Precipitated silica is often added to natural rubber compounds in order to improve performance in commercial application. A problem with using silica as filler is the poor compatibility between silica and natural rubber. In this research, polyisoprene was coated on silica surface by gamma ray induced ad micellar polymerization in order to achieve the better compatibility between silica and natural rubber. The modified silica was characterized by FT-IR, and SEM. The results show that polyisoprene was successfully coated on silica surface via gamma ray induced ad micellar polymerization
Sequencing of Australian wild rice genomes reveals ancestral relationships with domesticated rice.

Science.gov (United States)

Brozynska, Marta; Copetti, Dario; Furtado, Agnelo; Wing, Rod A; Crayn, Darren; Fox, Glen; Ishikawa, Ryuji; Henry, Robert J

2017-06-01

The related A genome species of the Oryza genus are the effective gene pool for rice. Here, we report draft genomes for two Australian wild A genome taxa: O. rufipogon-like population, referred to as Taxon A, and O. meridionalis-like population, referred to as Taxon B. These two taxa were sequenced and assembled by integration of short- and long-read next-generation sequencing (NGS) data to create a genomic platform for a wider rice gene pool. Here, we report that, despite the distinct chloroplast genome, the nuclear genome of the Australian Taxon A has a sequence that is much closer to that of domesticated rice (O. sativa) than to the other Australian wild populations. Analysis of 4643 genes in the A genome clade showed that the Australian annual, O. meridionalis, and related perennial taxa have the most divergent (around 3 million years) genome sequences relative to domesticated rice. A test for admixture showed possible introgression into the Australian Taxon A (diverged around 1.6 million years ago) especially from the wild indica/O. nivara clade in Asia. These results demonstrate that northern Australia may be the centre of diversity of the A genome Oryza and suggest the possibility that this might also be the centre of origin of this group and represent an important resource for rice improvement. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.
Deciphering the Environmental Impacts on Rice Quality for Different Rice Cultivated Areas.

Science.gov (United States)

Li, Xiukun; Wu, Lian; Geng, Xin; Xia, Xiuhong; Wang, Xuhong; Xu, Zhengjin; Xu, Quan

2018-01-19

Rice (Oryza sativa L.) is cultivated in a wide range of climatic conditions, and is one of mankind's major staple foods. The interaction of environmental factors with genotype effects major agronomic traits such as yield, quality, and resistance in rice. However, studies on the environmental factors affecting agronomic traits are often difficult to conduct because most environmental factors are dynamic and constantly changing. A series of recombinant inbred lines (RILs) derived from an indica/japonica cross were planted into four typical rice cultivated areas arranging from latitude N22° to N42°. The environmental data from the heading to mature (45 days) stages were recorded for each RIL in the four areas. We determined that light, temperature, and humidity significantly affected the milling quality and cooking quality overall the four areas. Within each area, these environmental factors mainly affected the head rice ratio, grain length, alkali consumption, and amylose and protein content. Moreover, the effect of these environmental factors dynamically changed from heading to mature stage. Compared to light and humidity, temperature was more stable and predictable, and night temperature showed a stronger correlation efficiency to cooking quality than day temperature, and the daily temperature range had contrary effects compared to day and night temperature on grain quality. The present study evaluated the critical phase during the grain filling stage by calculating the dynamic changes of correlation efficiency between the quality traits and climate parameters. Our findings suggest that the sowing date could be adjusted to improve rice quality so as to adjust for environmental changes.
Investigation of fused silica dynamic behaviour

International Nuclear Information System (INIS)

Malaise, F.; Chevalier, J.M.; Bertron, I.; Malka, F.

2006-01-01

The survivability of the fused silica shields to shrapnel impacts is a key factor for the affordable operation of the intense laser irradiation future facility Laser Mega Joule (LMJ). This paper presents experimental data and computational modelling for LMJ fused silica upon shock wave loading and unloading. Gas-gun flyer plate impact and explosively driven tests have been conducted to investigate the dynamic behaviour of this material. Hugoniot states and the Hugoniot Elastic Limit of LMJ fused silica have been obtained. These experimental data are useful for determining some constitutive model constants of the 'Crack-Model', a continuum tensile and compressive failure model with friction based. This model has been improved by taking into account nonlinear elasticity. The numerical results obtained by performing computations of the previous tests and some ballistic impact tests are discussed. The numerical comparisons with the experimental data show good agreement. Further developments to simulate the permanent densification and the solid-to-solid phase transformation of fused silica are required. (authors)

Response Of Lowland Rice To Soil Compaction

International Nuclear Information System (INIS)

Idawati; Haryanto

2000-01-01

Soil compaction, as a new tillage practice for paddy soil, is to substitute pudding in order to reduce land preparation cost. To study response of lowland rice to soil compaction, a pot experiment has been conducted which took place in the greenhouse of P3TIR-BATAN. Soil for experiment was taken from pusakanegara. Two factors (degree of soil compaction and rice variety) were combined. Degree of compaction was split into 3 levels (DI = normal; D215% more compact than normal; 30 % more compact than normal), and rice variety into 2 levels (IR64 and Atomita IV). KH 2 32 PO 4 solution was injected into the soil surrounding rice clump to test the root activity at blooming stage of rice plant. Data resulted from this experiment is presented together with additional data from some other experiments of fertilization in the research s erie to study soil compaction. Some information's from experiment results are as following. Both rice varieties tested gave the same response to soil compaction. Root activity, according to data of 32 P absorbed by plant, was not harmed by soil compaction at the degree tested in the experiment. This prediction is supported by the growth by rice observed at generative growth stage, in pot experiment as well as in field experiment, which showed that soil compaction tested did not decrease rice yield but in opposite in tended to increase the yield. In practising soil compaction in land preparation, fertilizers should be applied by deep placement to have higher increasing is rice yield
Silica uptake in aquatic and wetland macrophytes: a strategic choice between silica, lignin and cellulose?

Science.gov (United States)

Schoelynck, Jonas; Bal, Kris; Backx, Hans; Okruszko, Tomasz; Meire, Patrick; Struyf, Eric

2010-04-01

*Although silica (Si) is not an essential element for plant growth in the classical sense, evidence points towards its functionality for a better resistance against (a)biotic stress. Recently, it was shown that wetland vegetation has a considerable impact on silica biogeochemistry. However, detailed information on Si uptake in aquatic macrophytes is lacking. *We investigated the biogenic silica (BSi), cellulose and lignin content of 16 aquatic/wetland species along the Biebrza river (Poland) in June 2006 and 2007. The BSi data were correlated with cellulose and lignin concentrations. *Our results show that macrophytes contain significant amounts of BSi: between 2 and 28 mg BSi g(-1). This is in the same order of magnitude as wetland species (especially grasses). Significant antagonistic correlations were found between lignin, cellulose and BSi content. Interestingly, observed patterns were opposite for wetland macrophytes and true aquatic macrophytes. *We conclude that macrophytes have an overlooked but potentially vast storage capacity for Si. Study of their role as temporal silica sinks along the land-ocean continuum is needed. This will further understanding of the role of ecosystems on land ocean transport of this essential nutrient.
Zeolite and wollastonite synthesis from rice hull ash; Sintese de zeolitas e wolastonita a partir da cinza da casca de arroz

Energy Technology Data Exchange (ETDEWEB)

Fernandes, Alberto de Andrade

2006-07-01

Rice hull ash (RHA) is a industry scrap rich in amorphous silica. A simple and low-energy cost method for the extraction of this silica was researched. A low level of impurity and high reactivity material was produced, which is appropriate for the synthesis of zeolites and wollastonite (CaSiO{sub 3}). The synthetic zeolites has not similar structures in nature, and they have been more and more valued in the market due to their purity and efficiency in specific applications like ion exchange, molecular sieve and catalysis areas. High purity wollastonite has many applications in manufacturing and agriculture. The mineral wollastonite can be formed in nature in different ways; it is generally accepted two forming processes, both encompassing limestone metamorphism (heat and pressure). In this work, a new process for the synthesis of zeolites and wollastonite from RHA colloidal silica was developed. Moreover, the process is aimed at lower energy costs, fewer stages and fewer reactants consume. In this work, zeolite A used in detergent and zeolite ZSM-5, employed in the petrochemical industry due to its high selectivity in catalytic reactions and its high thermo and acid stability, were synthesized. The first step of the wollastonite synthesis was studied, with the purpose of obtaining calcium hydrosilicate. Eleven different hydrosilicates occur in the system Ca(OH){sub 2}-SiO{sub 2}-H{sub 2}O, in the second step it was annealed to form the wollastonite phase. (author)
Tillering and panicle branching genes in rice.

Science.gov (United States)

Liang, Wei-hong; Shang, Fei; Lin, Qun-ting; Lou, Chen; Zhang, Jing

2014-03-01

Rice (Oryza sativa L.) is one of the most important staple food crops in the world, and rice tillering and panicle branching are important traits determining grain yield. Since the gene MONOCULM 1 (MOC 1) was first characterized as a key regulator in controlling rice tillering and branching, great progress has been achieved in identifying important genes associated with grain yield, elucidating the genetic basis of yield-related traits. Some of these important genes were shown to be applicable for molecular breeding of high-yielding rice. This review focuses on recent advances, with emphasis on rice tillering and panicle branching genes, and their regulatory networks. Copyright © 2013 Elsevier B.V. All rights reserved.
Rice epigenomics and epigenetics: challenges and opportunities.

Science.gov (United States)

Chen, Xiangsong; Zhou, Dao-Xiu

2013-05-01

During recent years rice genome-wide epigenomic information such as DNA methylation and histone modifications, which are important for genome activity has been accumulated. The function of a number of rice epigenetic regulators has been studied, many of which are found to be involved in a diverse range of developmental and stress-responsive pathways. Analysis of epigenetic variations among different rice varieties indicates that epigenetic modification may lead to inheritable phenotypic variation. Characterizing phenotypic consequences of rice epigenomic variations and the underlining chromatin mechanism and identifying epialleles related to important agronomic traits may provide novel strategies to enhance agronomically favorable traits and grain productivity in rice. Copyright © 2013 Elsevier Ltd. All rights reserved.
Fungal diversity of rice straw for meju fermentation.

Science.gov (United States)

Kim, Dae-Ho; Kim, Seon-Hwa; Kwon, Soon-Wo; Lee, Jong-Kyu; Hong, Seung-Beom

2013-12-01

Rice straw is closely associated with meju fermentation and it is generally known that the rice straw provides meju with many kinds of microorganisms. In order to elucidate the origin of meju fungi, the fungal diversity of rice straw was examined. Rice straw was collected from 12 Jang factories where meju are produced, and were incubated under nine different conditions by altering the media (MEA, DRBC, and DG18), and temperature (15°C, 25°C, and 35°C). In total, 937 strains were isolated and identified as belonging to 39 genera and 103 species. Among these, Aspergillus, Cladosporium, Eurotium, Fusarium, and Penicillium were the dominant genera. Fusarium asiaticum (56.3%), Cladosporium cladosporioides (48.6%), Aspergillus tubingensis (37.5%), A. oryzae (31.9%), Eurotium repens (27.1%), and E. chevalieri (25.0%) were frequently isolated from the rice straw obtained from many factories. Twelve genera and 40 species of fungi that were isolated in the rice straw in this study were also isolated from meju. Specifically, A. oryzae, C. cladosporioides, E. chevalieri, E. repens, F. asiaticum, and Penicillium polonicum (11.8%), which are abundant species in meju, were also isolated frequently from rice straw. C. cladosporioides, F. asiaticum, and P. polonicum, which are abundant in the low temperature fermentation process of meju fermentation, were frequently isolated from rice straw incubated at 15°C and 25°C, whereas A. oryzae, E. repens, and E. chevalieri, which are abundant in the high temperature fermentation process of meju fermentation, were frequently isolated from rice straw incubated at 25°C and 35°C. This suggests that the mycobiota of rice straw has a large influence in the mycobiota of meju. The influence of fungi on the rice straw as feed and silage for livestock, and as plant pathogens for rice, are discussed as well.
Sulfate-reducing bacteria in rice field soil and on rice roots.

Science.gov (United States)

Wind, T; Stubner, S; Conrad, R

1999-05-01

Rice plants that were grown in flooded rice soil microcosms were examined for their ability to exhibit sulfate reducing activity. Washed excised rice roots showed sulfate reduction potential when incubated in anaerobic medium indicating the presence of sulfate-reducing bacteria. Rice plants, that were incubated in a double-chamber (phylloshpere and rhizosphere separated), showed potential sulfate reduction rates in the anoxic rhizosphere compartment. These rates decreased when oxygen was allowed to penetrate through the aerenchyma system of the plants into the anoxic root compartment, indicating that sulfate reducers on the roots were partially inhibited by oxygen or that sulfate was regenerated by oxidation of reduced S-compounds. The potential activity of sulfate reducers on rice roots was consistent with MPN enumerations showing that H2-utilizing sulfate-reducing bacteria were present in high numbers on the rhizoplane (4.1 x 10(7) g-1 root fresh weight) and in the adjacent rhizosperic soil (2.5 x 10(7) g-1 soil dry weight). Acetate-oxidizing sulfate reducers, on the other hand, showed highest numbers in the unplanted bulk soil (1.9 x 10(6) g-1 soil dry weight). Two sulfate reducing bacteria were isolated from the highest dilutions of the MPN series and were characterized physiologically and phylogenetically. Strain F1-7b which was isolated from the rhizoplane with H2 as electron donor was related to subgroup II of the family Desulfovibrionaceae. Strain EZ-2C2, isolated from the rhizoplane on acetate, grouped together with Desulforhabdus sp. and Syntrophobacter wolinii. Other strains of sulfate-reducing bacteria originated from bulk soil of rice soil microcosms and were isolated using different electron donors. From these isolates, strains R-AcA1, R-IbutA1, R-PimA1 and R-AcetonA170 were Gram-positive bacteria which were affiliated with the genus Desulfotomaculum. The other isolates were members of subgroup II of the Desulfovibrionaceae (R-SucA1 and R-LacA1), were
THE EFFECT OF RICE CULTIVARS ON METHANE EMISSION FROM IRRIGATED RICE FIELD

Directory of Open Access Journals (Sweden)

P. Setyanto

2016-10-01

Full Text Available Rice plants have been reported to affect methane (CH4 emission from rice fields. The objectives of this study were to determine the effect of rice cultivars on CH4 emission from flooded rice and to develop crop management strategies with low emitting rice cultivars while sustaining high yield. The four rice cultivars studied were Memberamo, Cisadane, IR64, and Way Apoburu. The CH4 emissions were determined in the wet season of 2001/2002 (November-February using an automated closed chamber technique in an irrigated field condition. Farmyard manure at the rate of 5 t ha-1 was given to the plots to ensure carbon was not limited. Root weight, root length, biomass, and number of tillers were determined at 17, 36, and 57 days after transplanting (DAT. The results showed that the mean CH4 emission was highest in the plot planted with Cisadane (94.8 kg CH4 ha-1, and the lowest with IR64 (37.7 kg CH4 ha-1. The plots treated with emberamo and Way Apoburu resulted an intermediate CH4 emission at the average of 61.1 and 58.9 kg CH4 ha-1, respectively. There was no significant difference in yield between the cultivars tested. The yield of Memberamo, Cisadane, IR64, and Way Apoburu were 5.882, 5.764, 5.873 and 6.065 t ha-1, respectively. Statistical analysis showed that there were no significant differences in the root weight and root length among cultivars. However, Cisadane gave the highest dry matter weight (222 g hill-1 at 57 DAT compared to the other cultivars (175-190 g hill-1. Plant tillers did not show significant differences between the cultivars. Regression analysis showed that CH4 flux was significantly related with root weight, root length, aboveground biomass, and number of plant tillers. This finding shows that the use of selected cultivars, such as IR64, can potentially lower CH4 emission without scarifying yield.
Mesoporous Silica: A Suitable Adsorbent for Amines

Directory of Open Access Journals (Sweden)

Abdollahzadeh-Ghom Sara

2009-01-01

Full Text Available Abstract Mesoporous silica with KIT-6 structure was investigated as a preconcentrating material in chromatographic systems for ammonia and trimethylamine. Its adsorption capacity was compared to that of existing commercial materials, showing its increased adsorption power. In addition, KIT-6 mesoporous silica efficiently adsorbs both gases, while none of the employed commercial adsorbents did. This means that KIT-6 Mesoporous silica may be a good choice for integrated chromatography/gas sensing micro-devices.
Assessment of irradiated rice bran as iron source

International Nuclear Information System (INIS)

Wada, Heden Katsue

2002-01-01

Rice is the largest cereal crop in Brazil. To obtain the polish grain, its external peel is extracted after abrasive process. As a result, rice bran is obtained. It has low cost and high nutritional level, which has been include into malnourished children feeding. There is a considerable controversy related to the rice bran effect on the prevention and control of undernutrition and iron deficiency. The aim os this study was to assess the availability of in vitro iron of in natura and treated rice brans, after different levels of irradiation were applied. Both sorts of bran had their composition analyzed emphasizing the iron and phytate contents. The microbiological quality of the rice bran was also assessed. The pathogenic microorganisms were destroyed only in the in natura rice bran. As the irradiation level applied on the stabilized bran increased, its lipidic fraction reduced an the progressive destruction of the phytates occurred. The high iron content follow its availability in the rice bran, despite of the irradiation level applied, on the rice bran products and its dietetic preparations. (author)
Tier I Rice Model - Version 1.0 - Guidance for Estimating Pesticide Concentrations in Rice Paddies

Science.gov (United States)

Describes a Tier I Rice Model (Version 1.0) for estimating surface water exposure from the use of pesticides in rice paddies. The concentration calculated can be used for aquatic ecological risk and drinking water exposure assessments.
Global Rice Watch: Spatial-temporal dynamics, driving factors, and impacts of paddy rice agriculture in the world

Science.gov (United States)

Xiao, X.; Dong, J.; Zhang, G.; Xin, F.; Li, X.

2017-12-01

Paddy rice croplands account for more than 12% of the global cropland areas, and provide food to feed more than 50% of the world population. Spatial patterns and temporal dynamics of paddy rice croplands have changed remarkably in the past decades, driven by growing human population and their changing diet structure, land use (e.g., urbanization, industrialization), climate, markets, and technologies. In this presentation, we will provide a comprehensive review of our current knowledge on (1) the spatial patterns and temporal dynamics of paddy rice croplands from agricultural statistics data and remote sensing approaches; (2) major driving factors for the observed changes in paddy rice areas, including social, economic, climate, land use, markets, crop breeding technology, and farming technology; and (3) major impacts on atmospheric methane concentration, land surface temperature, water resources and use, and so on. We will highlight the results from a few case studies in China and monsoon Asia. We will also call for a global synthesis analysis of paddy rice agriculture, and invite researchers to join the effort to write and edit a book that provides comprehensive and updated knowledge on paddy rice agriculture.
Brazilian energy

International Nuclear Information System (INIS)

O'Shaughnessy, H.

1997-04-01

Brazilian Energy provides all the information necessary for energy companies to invest and operate in Brazil, including: a review of Brazil's natural resources; an assessment of privatisation strategies at the federal, state and regional level; an analysis of the electricity industry and the future for Electrobras; an analysis of the oil industry and, in particular, Petrobras; a discussion of the fuel alcohol industry; the discovery of local natural gas, its prospects and the involvement of the auto industry; an assessment of the problems facing the coal industry and its future; a discussion of the regulatory framework for the newly privatised companies; the importance of intra-regional energy links and the booming membership of Mercosur; the difficulties experienced by foreign investors doing business in Brazil; brief profiles of the key energy companies; profiles of key people influencing the privatisation process in Brazil. Brazilian energy is essential reading for those wishing to advise and assist Brazil in this period of change and development, as well as those who wish to invest or become key players in the Brazilian energy sector. (author)
Pedogenic silica accumulation in chronosequence soils, southern California

Science.gov (United States)

Kendrick, K.J.; Graham, R.C.

2004-01-01

Chronosequential analysis of soil properties has proven to be a valuable approach for estimating ages of geomorphic surfaces where no independent age control exists. In this study we examined pedogenic silica as an indicator of relative ages of soils and geomorphic surfaces, and assessed potential sources of the silica. Pedogenic opaline silica was quantified by tiron (4,5-dihydroxy-1,3-benzene-disulfonic acid [disodium salt], C6H 4Na2O8S2) extraction for pedons in two different chromosequences in southern California, one in the San Timoteo Badlands and one in Cajon Pass. The soils of hoth of these chronosequences are developed in arkosic sediments and span 11.5 to 500 ka. The amount of pedogenic silica increases with increasing duration of pedogenesis, and the depth of the maximum silica accumulation generally coincides with the maximum expression of the argillic horizon. Pedogenic silica has accumulated in all of the soils, ranging from 1.2% tiron-extractable Si (Sitn) in the youngest soil to 4.6% in the oldest. Primary Si decreases with increasing duration of weathering, particularly in the upper horizons, where weathering conditions are most intense. The loss of Si coincides with the loss of Na and K, implicating the weathering of feld-spars as the likely source of Si loss. The quantity of Si lost in the upper horizons is adequate to account for the pedogenic silica accumulation in the subsoil. Pedogenic silica was equally effective as pedogenic Fe oxides as an indicator of relative soil age in these soils.
[Quality of pastas supplemented with rice bran].

Science.gov (United States)

Sangronis, E; Rebolledo, M A

1997-06-01

The objective of this research was to investigate the potential of using rice bran as an ingredient in pastas spaghetti type. Two of the pastas were made with semolina from durum as raw material, supplemented with 10 and 20% rice bran. The other two were made with granular flour and the same percentage of rice bran. Proximate composition of raw material was analyzed. Pastas were elaborated in a local industry. Composition, proximal, color, texture, and sensorial quality of pastas were determined. Protein content (13.9-15.0%), ash (1.47-3.09%) and dietary fiber (6.71-8.45%) of pastas increased according to the percentage of rice bran added. The hardest pastas were those elaborated with semolina from durum wheat and with a 10% of substitution. Also, they were the most yellow. The sensory panel found differences in quality among the pastas evaluated. Pastas with 10% rice bran had the best quality. The results demonstrated that is possible to elaborate pastas with 20% as maximum of rice bran resulting products with high protein, ash and dietetic fiber content, but some undesirable characteristics were given by the rice bran as white spots, wrinkles and color changes.
A novel method to characterize silica bodies in grasses.

Science.gov (United States)

Dabney, Clemon; Ostergaard, Jason; Watkins, Eric; Chen, Changbin

2016-01-01

The deposition of silicon into epidermal cells of grass species is thought to be an important mechanism that plants use as a defense against pests and environmental stresses. There are a number of techniques available to study the size, density and distribution pattern of silica bodies in grass leaves. However, none of those techniques can provide a high-throughput analysis, especially for a great number of samples. We developed a method utilizing the autofluorescence of silica bodies to investigate their size and distribution, along with the number of carbon inclusions within the silica bodies of perennial grass species Koeleria macrantha. Fluorescence images were analyzed by image software Adobe Photoshop CS5 or ImageJ that remarkably facilitated the quantification of silica bodies in the dry ash. We observed three types of silica bodies or silica body related mineral structures. Silica bodies were detected on both abaxial and adaxial epidermis of K. macrantha leaves, although their sizes, density, and distribution patterns were different. No auto-fluorescence was detected from carbon inclusions. The combination of fluorescence microscopy and image processing software displayed efficient utilization in the identification and quantification of silica bodies in K. macrantha leaf tissues, which should applicable to biological, ecological and geological studies of grasses including forage, turf grasses and cereal crops.
Breeding of ozone resistant rice: Relevance, approaches and challenges

International Nuclear Information System (INIS)

Frei, Michael

2015-01-01

Tropospheric ozone concentrations have been rising across Asia, and will continue to rise during the 21st century. Ozone affects rice yields through reductions in spikelet number, spikelet fertility, and grain size. Moreover, ozone leads to changes in rice grain and straw quality. Therefore the breeding of ozone tolerant rice varieties is warranted. The mapping of quantitative trait loci (QTL) using bi-parental populations identified several tolerance QTL mitigating symptom formation, grain yield losses, or the degradation of straw quality. A genome-wide association study (GWAS) demonstrated substantial natural genotypic variation in ozone tolerance in rice, and revealed that the genetic architecture of ozone tolerance in rice is dominated by multiple medium and small effect loci. Transgenic approaches targeting tolerance mechanisms such as antioxidant capacity are also discussed. It is concluded that the breeding of ozone tolerant rice can contribute substantially to the global food security, and is feasible using different breeding approaches. - Highlights: • Tropospheric ozone affects millions of hectares of rice land. • Ozone affects rice yield and quality. • Breeding approaches to adapt rice to high ozone are discussed. • Challenges in the breeding of ozone resistant rice are discussed. - This review summarizes the effects of tropospheric ozone on rice and outlines approaches and challenges in the breeding of adapted varieties
Gas-phase acylation of aminopropyl-silica gel in the synthesis of some chemically bonded silica materials for analytical applications

International Nuclear Information System (INIS)

Basiuk, Vladimir; Khil'chevskaya, E.G.

1991-01-01

Gas-phase acylation of aminopropyl-silica gel with aliphatic dicarboxylic (succinic, adipic and sebacic) and 4-aminobenzoic acids is proposed as a rapid and efficient one-step method for the synthesis of carboxyalkyl- and 4-aminophenylamidopropyl-silica gels, usually used as zwitterion exchangers for liquid chromatography and matrices for multi-step syntheses of silica-bound aromatic azo reagents for the sorption and chromatographic separation of metal ions. Acylation degrees of 59-90% are achieved after 0.5 h. IR spectra of the acylation products and near-UV-visible spectra for bonded aromatic azo compounds, based on 4-aminobenzamidopropyl-silica gel, are presented. Some positive and negative aspects of the gas-phase acylation are discussed. (author). 34 refs.; 2 figs.; 2 tabs
Estimation of rice yield affected by drought and relation between rice yield and TVDI

Science.gov (United States)

Hongo, C.; Tamura, E.; Sigit, G.

2016-12-01

Impact of climate change is not only seen on food production but also on food security and sustainable development of society. Adaptation to climate change is a pressing issue throughout the world to reduce the risks along with the plans and strategies for food security and sustainable development. As a key adaptation to the climate change, agricultural insurance is expected to play an important role in stabilizing agricultural production through compensating the losses caused by the climate change. As the adaptation, the Government of Indonesia has launched agricultural insurance program for damage of rice by drought, flood and pest and disease. The Government started a pilot project in 2013 and this year the pilot project has been extended to 22 provinces. Having the above as background, we conducted research on development of new damage assessment method for rice using remote sensing data which could be used for evaluation of damage ratio caused by drought in West Java, Indonesia. For assessment of the damage ratio, estimation of rice yield is a key. As the result of our study, rice yield affected by drought in dry season could be estimated at level of 1 % significance using SPOT 7 data taken in 2015, and the validation result was 0.8t/ha. Then, the decrease ratio in rice yield about each individual paddy field was calculated using data of the estimated result and the average yield of the past 10 years. In addition, TVDI (Temperature Vegetation Dryness Index) which was calculated from Landsat8 data in heading season indicated the dryness in low yield area. The result suggests that rice yield was affected by irrigation water shortage around heading season as a result of the decreased precipitation by El Nino. Through our study, it becomes clear that the utilization of remote sensing data can be promising for assessment of the damage ratio of rice production precisely, quickly and quantitatively, and also it can be incorporated into the insurance procedures.
Consumer preference mapping for rice product concepts

NARCIS (Netherlands)

Suwannaporn, P.; Linnemann, A.R.; Chaveesuk, R.

2008-01-01

Purpose - Rice consumption per capita in many Asian countries is decreasing constantly, but American and European citizens are eating more rice nowadays. A preference study among consumers was carried out with the aim of determining new rice product characteristics in order to support export of Thai

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