[Research on determination of chemical purity of andrographolide by coulometric titration method].

Science.gov (United States)

Yang, Ning; Yang, Dezhi; Xu, Lishen; Lv, Yang

2010-04-01

The determination of chemical purity of andrographolide by coulometric titration method is studied in this paper. The coulometric titration was carried out in a mixture composed of 4 mol x L(-1) hydrochloric acid and 1 mol x L(-1) potassium bromide solution and 1 mol x L(-1) potassium nitrate solution (1:1). Bromine is electrogenerated at the anode and reacts with the andrographolide. The number of electrons involved in the eleatrode reaction is 2. Purity of andrographolide is 99.76% compared with 99.77% utilizing area normalization method by HPLC. The RSD are 0.33% and 0.02% respectively. The results from two methods are consistent, so the determination of chemical purity of andrographolide by coulometric titration method is scientific and feasible. The method is rapid, simple, convenient, sensitive and accurate. The reference material is not essential in the method. The method is suitable for determination of chemical purity of andrographolide.

Simple methods for the 3' biotinylation of RNA.

Science.gov (United States)

Moritz, Bodo; Wahle, Elmar

2014-03-01

Biotinylation of RNA allows its tight coupling to streptavidin and is thus useful for many types of experiments, e.g., pull-downs. Here we describe three simple techniques for biotinylating the 3' ends of RNA molecules generated by chemical or enzymatic synthesis. First, extension with either the Schizosaccharomyces pombe noncanonical poly(A) polymerase Cid1 or Escherichia coli poly(A) polymerase and N6-biotin-ATP is simple, efficient, and generally applicable independently of the 3'-end sequences of the RNA molecule to be labeled. However, depending on the enzyme and the reaction conditions, several or many biotinylated nucleotides are incorporated. Second, conditions are reported under which splint-dependent ligation by T4 DNA ligase can be used to join biotinylated and, presumably, other chemically modified DNA oligonucleotides to RNA 3' ends even if these are heterogeneous as is typical for products of enzymatic synthesis. Third, we describe the use of 29 DNA polymerase for a template-directed fill-in reaction that uses biotin-dUTP and, thanks to the enzyme's proofreading activity, can cope with more extended 3' heterogeneities.

A new cascade method for studying isotope effect in chemical exchange system without valance change

International Nuclear Information System (INIS)

Wen Xiaoning; Luo Wenzong

1987-01-01

A new cascade method for studying isotope effect in chemical exchange system without valance change is developed and described. This method is simple to use and consumes less extractant as compared with the commonly used Woodward method. It is also convenient for unstable systems

Deciding which chemical mixtures risk assessment methods work best for what mixtures

International Nuclear Information System (INIS)

Teuschler, Linda K.

2007-01-01

The most commonly used chemical mixtures risk assessment methods involve simple notions of additivity and toxicological similarity. Newer methods are emerging in response to the complexities of chemical mixture exposures and effects. Factors based on both science and policy drive decisions regarding whether to conduct a chemical mixtures risk assessment and, if so, which methods to employ. Scientific considerations are based on positive evidence of joint toxic action, elevated human exposure conditions or the potential for significant impacts on human health. Policy issues include legislative drivers that may mandate action even though adequate toxicity data on a specific mixture may not be available and risk assessment goals that impact the choice of risk assessment method to obtain the amount of health protection desired. This paper discusses three important concepts used to choose among available approaches for conducting a chemical mixtures risk assessment: (1) additive joint toxic action of mixture components; (2) toxicological interactions of mixture components; and (3) chemical composition of complex mixtures. It is proposed that scientific support for basic assumptions used in chemical mixtures risk assessment should be developed by expert panels, risk assessment methods experts, and laboratory toxicologists. This is imperative to further develop and refine quantitative methods and provide guidance on their appropriate applications. Risk assessors need scientific support for chemical mixtures risk assessment methods in the form of toxicological data on joint toxic action for high priority mixtures, statistical methods for analyzing dose-response for mixtures, and toxicological and statistical criteria for determining sufficient similarity of complex mixtures

Simple gas chromatographic method for furfural analysis.

Science.gov (United States)

Gaspar, Elvira M S M; Lopes, João F

2009-04-03

A new, simple, gas chromatographic method was developed for the direct analysis of 5-hydroxymethylfurfural (5-HMF), 2-furfural (2-F) and 5-methylfurfural (5-MF) in liquid and water soluble foods, using direct immersion SPME coupled to GC-FID and/or GC-TOF-MS. The fiber (DVB/CAR/PDMS) conditions were optimized: pH effect, temperature, adsorption and desorption times. The method is simple and accurate (RSDfurfurals will contribute to characterise and quantify their presence in the human diet.

Simple quantification of surface carboxylic acids on chemically oxidized multi-walled carbon nanotubes

Science.gov (United States)

Gong, Hyejin; Kim, Seong-Taek; Lee, Jong Doo; Yim, Sanggyu

2013-02-01

The surface of multi-walled carbon nanotube (MWCNT) was chemically oxidized using nitric acid and sulfuric-nitric acid mixtures. Thermogravimetric analysis, transmission electron microscopy and infrared spectroscopy revealed that the use of acid mixtures led to higher degree of oxidation. More quantitative identification of surface carboxylic acids was carried out using X-ray photoelectron spectroscopy (XPS) and acid-base titration. However, these techniques are costly and require very long analysis times to promptly respond to the extent of the reaction. We propose a much simpler method using pH measurements and pre-determined pKa value in order to estimate the concentration of carboxylic acids on the oxidized MWCNT surfaces. The results from this technique were consistent with those obtained from XPS and titration, and it is expected that this simple quantification method can provide a cheap and fast way to monitor and control the oxidation reaction of MWCNT.

A simple method for HPLC retention time prediction: linear calibration using two reference substances.

Science.gov (United States)

Sun, Lei; Jin, Hong-Yu; Tian, Run-Tao; Wang, Ming-Juan; Liu, Li-Na; Ye, Liu-Ping; Zuo, Tian-Tian; Ma, Shuang-Cheng

2017-01-01

Analysis of related substances in pharmaceutical chemicals and multi-components in traditional Chinese medicines needs bulk of reference substances to identify the chromatographic peaks accurately. But the reference substances are costly. Thus, the relative retention (RR) method has been widely adopted in pharmacopoeias and literatures for characterizing HPLC behaviors of those reference substances unavailable. The problem is it is difficult to reproduce the RR on different columns due to the error between measured retention time (t R ) and predicted t R in some cases. Therefore, it is useful to develop an alternative and simple method for prediction of t R accurately. In the present study, based on the thermodynamic theory of HPLC, a method named linear calibration using two reference substances (LCTRS) was proposed. The method includes three steps, procedure of two points prediction, procedure of validation by multiple points regression and sequential matching. The t R of compounds on a HPLC column can be calculated by standard retention time and linear relationship. The method was validated in two medicines on 30 columns. It was demonstrated that, LCTRS method is simple, but more accurate and more robust on different HPLC columns than RR method. Hence quality standards using LCTRS method are easy to reproduce in different laboratories with lower cost of reference substances.

A simple method for accurate endotracheal placement of an intubation tube in Guinea pigs to assess lung injury following chemical exposure.

Science.gov (United States)

Nambiar, M P; Gordon, R K; Moran, T S; Richards, S M; Sciuto, A M

2007-01-01

ABSTRACT Guinea pigs are considered as the animal model of choice for toxicology and medical countermeasure studies against chemical warfare agents (CWAs) and toxic organophosphate pesticides because of the low levels of carboxylesterase compared to rats and mice. However, it is difficult to intubate guinea pigs without damaging the larynx to perform CWA inhalation experiments. We describe an easy technique of intubation of guinea pigs for accurate endotracheal placement of the intubation tube. The technique involves a speculum made by cutting the medium-size ear speculum in the midline leaving behind the intact circular connector to the otoscope. Guinea pigs were anesthetized with Telazol/meditomidine, the tongue was pulled using blunt forceps, and an otoscope attached with the specially prepared speculum was inserted gently. Insertion of the speculum raises the epiglottis and restrains the movements of vocal cord, which allows smooth insertion of the metal stylet-reinforced intubation tube. Accurate endotracheal placement of the intubation tube was achieved by measuring the length from the tracheal bifurcation to vocal cord and vocal cord to the upper front teeth. The average length of the trachea in guinea pigs (275 +/- 25 g) was 5.5 +/- 0.2 cm and the distance from the vocal cord to the front teeth was typically 3 cm. Coinciding an intubation tube marked at 6 cm with the upper front teeth accurately places the intubation tube 2.5 cm above the tracheal bifurcation. This simple method of intubation does not disturb the natural flora of the mouth and causes minimum laryngeal damage. It is rapid and reliable, and will be very valuable in inhalation exposure to chemical/biological warfare agents or toxic chemicals to assess respiratory toxicity and develop medical countermeasures.

Atomic force microscopy of histological sections using a chemical etching method

International Nuclear Information System (INIS)

Tiribilli, B.; Bani, D.; Quercioli, F.; Ghirelli, A.; Vassalli, M.

2005-01-01

Physiology and pathology have a big deal on tissue morphology, and the intrinsic spatial resolution of an atomic force microscope (AFM) is able to observe ultrastructural details. In order to investigate cellular and subcellular structures in histological sections with the AFM, we used a new simple method for sample preparation, i.e. chemical etching of semithin sections from epoxy resin-embedded specimens: such treatment appears to melt the upper layers of the embedding resin; thus, removing the superficial roughness caused by the edge of the microtome knife and bringing into high relief the biological structures hidden in the bulk. Consecutive ultrathin sections embedded in epoxy resin were observed with a transmission electron microscope (TEM) to compare the different imaging properties on the same specimen sample. In this paper we report, as an example, our AFM and TEM images of two different tissue specimens, rat pancreas and skeletal muscle fibres, showing that most of the inner details are visible with the AFM. These results suggest that chemical etching of histological sections may be a simple, fast and cost-effective method for AFM imaging with ultrastructural resolution

Simple method for calculating island widths

International Nuclear Information System (INIS)

Cary, J.R.; Hanson, J.D.; Carreras, B.A.; Lynch, V.E.

1989-01-01

A simple method for calculating magnetic island widths has been developed. This method uses only information obtained from integrating along the closed field line at the island center. Thus, this method is computationally less intensive than the usual method of producing surfaces of section of sufficient detail to locate and resolve the island separatrix. This method has been implemented numerically and used to analyze the buss work islands of ATF. In this case the method proves to be accurate to at least within 30%. 7 refs

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

Directory of Open Access Journals (Sweden)

Edem Cudjoe Bensah

2013-01-01

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

Simple Calculation Programs for Biology Immunological Methods

Indian Academy of Sciences (India)

First page Back Continue Last page Overview Graphics. Simple Calculation Programs for Biology Immunological Methods. Computation of Ab/Ag Concentration from EISA data. Graphical Method; Raghava et al., 1992, J. Immuno. Methods 153: 263. Determination of affinity of Monoclonal Antibody. Using non-competitive ...

A simple two-step method to fabricate highly transparent ITO/polymer nanocomposite films

International Nuclear Information System (INIS)

Liu, Haitao; Zeng, Xiaofei; Kong, Xiangrong; Bian, Shuguang; Chen, Jianfeng

2012-01-01

Highlights: ► A simple two-step method without further surface modification step was employed. ► ITO nanoparticles were easily to be uniformly dispersed in polymer matrix. ► ITO/polymer nanocomposite film had high transparency and UV/IR blocking properties. - Abstract: Transparent functional indium tin oxide (ITO)/polymer nanocomposite films were fabricated via a simple approach with two steps. Firstly, the functional monodisperse ITO nanoparticles were synthesized via a facile nonaqueous solvothermal method using bifunctional chemical agent (N-methyl-pyrrolidone, NMP) as the reaction solvent and surface modifier. Secondly, the ITO/acrylics polyurethane (PUA) nanocomposite films were fabricated by a simple sol-solution mixing method without any further surface modification step as often employed traditionally. Flower-like ITO nanoclusters with about 45 nm in diameter were mono-dispersed in ethyl acetate and each nanocluster was assembled by nearly spherical nanoparticles with primary size of 7–9 nm in diameter. The ITO nanoclusters exhibited an excellent dispersibility in polymer matrix of PUA, remaining their original size without any further agglomeration. When the loading content of ITO nanoclusters reached to 5 wt%, the transparent functional nanocomposite film featured a high transparency more than 85% in the visible light region (at 550 nm), meanwhile cutting off near-infrared radiation about 50% at 1500 nm and blocking UV ray about 45% at 350 nm. It could be potential for transparent functional coating materials applications.

Simple and fast fluorescence detection of benzoyl peroxide in wheat flour by N-methoxy rhodamine-6G spirolactam based on consecutive chemical reactions

International Nuclear Information System (INIS)

Chen Wei; Shi Wen; Li Zhao; Ma Huimin; Liu Yang; Zhang Jinghua; Liu Qingjun

2011-01-01

Graphical abstract: A simple and fast method for fluorescence detection of benzoyl peroxide in wheat flour by N-methoxy rhodamine-6G spirolactam (1) is proposed based on consecutive chemical reactions. Highlights: ► Benzoyl peroxide can oxidize Fe 2+ into Fe 3+ . ► Fe 3+ selectively induces the opening of rhodamine spirolactam ring. ► The two reactions led to the development of a new fluorescent method for benzoyl peroxide. ► The method is simple and fast, and is used to detect benzoyl peroxide in wheat flour. - Abstract: Benzoyl peroxide (BPO) as a brightener is often added to wheat flour, and excessive use of this food additive is receiving increasing concern. Herein, a simple and fast method for fluorescence detection of BPO is proposed based on consecutive chemical reactions. In this approach, BPO first oxidizes Fe 2+ into Fe 3+ and the resulting Fe 3+ then induces the opening of the spirolactam ring of a new rhodamine derivative, N-methoxy rhodamine-6G spirolactam, switching on fluorescence of the detection system. More importantly, the fluorescence response of the reaction system to BPO is rather rapid and sensitive, with a detection limit of 6 mg kg −1 (k = 3), which makes it to be of great potential use in food safety analysis. The applicability of the proposed method has been successfully demonstrated on the determination of BPO in wheat flour samples.

A Simple Preparation Method for Diphosphoimidazole

DEFF Research Database (Denmark)

Rosenberg, T.

1964-01-01

A simple method for the preparation of diphosphoimidazole is presented that involves direct phosphorylation of imidazole by phosphorus oxychloride in alkaline aqueous solution. Details are given on the use of diphosphoimidazole in preparing sodium phosphoramidate and certain phosphorylated amino...

A simple alpha spectrometric method for the measurement of transuranics in water samples from the nuclear power plant

International Nuclear Information System (INIS)

Chourasiya, G.; Verma, P.C.; Sebastian, Letha

1997-01-01

A simple one step method is described for the simultaneous determination of all the alpha-emitting transuranic nuclides in the primary circuit of the nuclear power plant. The method exploits the intrinsic chemical characteristics of the system and obviates the use of external chemicals. At the pH of the system (8-10) hydroxides of the actinides are coprecipitated with Fe(III) present as corrosion product. This precipitate is collected on a 25 mm membrane filter with 0.1 m pore in a form suitable for alpha spectrometry without need for electrodeposition. The alpha spectrum is comparable to that obtained with electrodeposition. The method gives consistently higher yield (>90%) and does not need use of tracers for the quantitative determinations. (author). 3 refs., 1 fig., 1 tab

A simple method for human peripheral blood monocyte Isolation

Directory of Open Access Journals (Sweden)

Marcos C de Almeida

2000-04-01

Full Text Available We describe a simple method using percoll gradient for isolation of highly enriched human monocytes. High numbers of fully functional cells are obtained from whole blood or buffy coat cells. The use of simple laboratory equipment and a relatively cheap reagent makes the described method a convenient approach to obtaining human monocytes.

A simple headspace equilibration method for measuring dissolved methane

Science.gov (United States)

Magen, C; Lapham, L.L.; Pohlman, John W.; Marshall, Kristin N.; Bosman, S.; Casso, Michael; Chanton, J.P.

2014-01-01

Dissolved methane concentrations in the ocean are close to equilibrium with the atmosphere. Because methane is only sparingly soluble in seawater, measuring it without contamination is challenging for samples collected and processed in the presence of air. Several methods for analyzing dissolved methane are described in the literature, yet none has conducted a thorough assessment of the method yield, contamination issues during collection, transport and storage, and the effect of temperature changes and preservative. Previous extraction methods transfer methane from water to gas by either a "sparge and trap" or a "headspace equilibration" technique. The gas is then analyzed for methane by gas chromatography. Here, we revisit the headspace equilibration technique and describe a simple, inexpensive, and reliable method to measure methane in fresh and seawater, regardless of concentration. Within the range of concentrations typically found in surface seawaters (2-1000 nmol L-1), the yield of the method nears 100% of what is expected from solubility calculation following the addition of known amount of methane. In addition to being sensitive (detection limit of 0.1 ppmv, or 0.74 nmol L-1), this method requires less than 10 min per sample, and does not use highly toxic chemicals. It can be conducted with minimum materials and does not require the use of a gas chromatograph at the collection site. It can therefore be used in various remote working environments and conditions.

Semiclassical methods in chemical reaction dynamics

Energy Technology Data Exchange (ETDEWEB)

Keshavamurthy, Srihari [Univ. of California, Berkeley, CA (United States)

1994-12-01

Semiclassical approximations, simple as well as rigorous, are formulated in order to be able to describe gas phase chemical reactions in large systems. We formulate a simple but accurate semiclassical model for incorporating multidimensional tunneling in classical trajectory simulations. This model is based on the existence of locally conserved actions around the saddle point region on a multidimensional potential energy surface. Using classical perturbation theory and monitoring the imaginary action as a function of time along a classical trajectory we calculate state-specific unimolecular decay rates for a model two dimensional potential with coupling. Results are in good comparison with exact quantum results for the potential over a wide range of coupling constants. We propose a new semiclassical hybrid method to calculate state-to-state S-matrix elements for bimolecular reactive scattering. The accuracy of the Van Vleck-Gutzwiller propagator and the short time dynamics of the system make this method self-consistent and accurate. We also go beyond the stationary phase approximation by doing the resulting integrals exactly (numerically). As a result, classically forbidden probabilties are calculated with purely real time classical trajectories within this approach. Application to the one dimensional Eckart barrier demonstrates the accuracy of this approach. Successful application of the semiclassical hybrid approach to collinear reactive scattering is prevented by the phenomenon of chaotic scattering. The modified Filinov approach to evaluating the integrals is discussed, but application to collinear systems requires a more careful analysis. In three and higher dimensional scattering systems, chaotic scattering is suppressed and hence the accuracy and usefulness of the semiclassical method should be tested for such systems.

Semiclassical methods in chemical reaction dynamics

International Nuclear Information System (INIS)

Keshavamurthy, S.

1994-12-01

Semiclassical approximations, simple as well as rigorous, are formulated in order to be able to describe gas phase chemical reactions in large systems. We formulate a simple but accurate semiclassical model for incorporating multidimensional tunneling in classical trajectory simulations. This model is based on the existence of locally conserved actions around the saddle point region on a multidimensional potential energy surface. Using classical perturbation theory and monitoring the imaginary action as a function of time along a classical trajectory we calculate state-specific unimolecular decay rates for a model two dimensional potential with coupling. Results are in good comparison with exact quantum results for the potential over a wide range of coupling constants. We propose a new semiclassical hybrid method to calculate state-to-state S-matrix elements for bimolecular reactive scattering. The accuracy of the Van Vleck-Gutzwiller propagator and the short time dynamics of the system make this method self-consistent and accurate. We also go beyond the stationary phase approximation by doing the resulting integrals exactly (numerically). As a result, classically forbidden probabilties are calculated with purely real time classical trajectories within this approach. Application to the one dimensional Eckart barrier demonstrates the accuracy of this approach. Successful application of the semiclassical hybrid approach to collinear reactive scattering is prevented by the phenomenon of chaotic scattering. The modified Filinov approach to evaluating the integrals is discussed, but application to collinear systems requires a more careful analysis. In three and higher dimensional scattering systems, chaotic scattering is suppressed and hence the accuracy and usefulness of the semiclassical method should be tested for such systems

Simple Calculation Programs for Biology Other Methods

Indian Academy of Sciences (India)

First page Back Continue Last page Overview Graphics. Simple Calculation Programs for Biology Other Methods. Hemolytic potency of drugs. Raghava et al., (1994) Biotechniques 17: 1148. FPMAP: methods for classification and identification of microorganisms 16SrRNA. graphical display of restriction and fragment map of ...

Chemical potential of one-dimensional simple harmonic oscillators

International Nuclear Information System (INIS)

Mungan, Carl E

2009-01-01

Expressions for the chemical potential of an Einstein solid, and of ideal Fermi and Bose gases in an external one-dimensional oscillatory trap, are calculated by two different methods and are all found to share the same functional form. These derivations are easier than traditional textbook calculations for an ideal gas in an infinite three-dimensional square well. Furthermore, the results indicate some important features of chemical potential that could promote student learning in an introductory course in statistical mechanics at the undergraduate level.

Fabricating superhydrophobic polymer surfaces with excellent abrasion resistance by a simple lamination templating method.

Science.gov (United States)

Xu, Qian Feng; Mondal, Bikash; Lyons, Alan M

2011-09-01

Fabricating robust superhydrophobic surfaces for commercial applications is challenging as the fine-scale surface features, necessary to achieve superhydrophobicity, are susceptible to mechanical damage. Herein, we report a simple and inexpensive lamination templating method to create superhydrophobic polymer surfaces with excellent abrasion resistance and water pressure stability. To fabricate the surfaces, polyethylene films were laminated against woven wire mesh templates. After cooling, the mesh was peeled from the polymer creating a 3D array of ordered polymer microposts on the polymer surface. The resulting texture is monolithic with the polymer film and requires no chemical modification to exhibit superhydrophobicity. By controlling lamination parameters and mesh dimensions, polyethylene surfaces were fabricated that exhibit static contact angles of 160° and slip angles of 5°. Chemical and mechanical stability was evaluated using an array of manual tests as well as a standard reciprocating abraser test. Surfaces remained superhydrophobic after more than 5500 abrasion cycles at a pressure of 32.0 kPa. In addition, the surface remains dry after immersing into water for 5 h at 55 kPa. This method is environmental friendly, as it employs no solvents or harsh chemicals and may provide an economically viable path to manufacture large areas of mechanically robust superhydrophobic surfaces from inexpensive polymers and reusable templates.

Simple and inexpensive method for CT-guided stereotaxy

Energy Technology Data Exchange (ETDEWEB)

Wester, K; Sortland, O; Hauglie-Hanssen, E

1981-01-01

A simple and inexpensive method for CT-guided stereotaxy is described. The method requires neither sophisticated computer programs nor additional stereotactic equipment, such as special head holders for the CT, and can be easily obtained without technical assistance. The method is designed to yield the vertical coordinates.

Evaluation of Simple Treat 3.0 for two hydrophobic and slowly biodegradable chemicals: Polycyclic musks HHCB and AHTN

NARCIS (Netherlands)

Artola-Garicano, E.; Hermens, J.L.M.; Vaes, W.H.J.

2003-01-01

In the current study, predictions by Simple Treat 3.0, a fate model for organic chemicals in sewage treatment plants (STPs), are compared with actual measurements in three STPs. Two polycyclic musks, Tonalide® (AHTN) and Galaxolide® (HHCB), were used for model evaluation. Results show that Simple

A Simple Educational Method for the Measurement of Liquid Binary Diffusivities

Science.gov (United States)

Rice, Nicholas P.; de Beer, Martin P.; Williamson, Mark E.

2014-01-01

A simple low-cost experiment has been developed for the measurement of the binary diffusion coefficients of liquid substances. The experiment is suitable for demonstrating molecular diffusion to small or large undergraduate classes in chemistry or chemical engineering. Students use a cell phone camera in conjunction with open-source image…

A simple cost-effective and eco-friendly wet chemical process for the fabrication of superhydrophobic cotton fabrics

International Nuclear Information System (INIS)

Richard, Edna; Lakshmi, R.V.; Aruna, S.T.; Basu, Bharathibai J.

2013-01-01

Superhydrophobic surfaces were created on hydrophilic cotton fabrics by a simple wet chemical process. The fabric was immersed in a colloidal suspension of zinc hydroxide followed by subsequent hydrophobization with stearic acid. The wettability of the modified cotton fabric sample was studied by water contact angle (WCA) and water shedding angle (WSA) measurements. The modified cotton fabrics exhibited superhydrophobicity with a WCA of 151° for 8 μL water droplet and a WSA of 5–10° for 40 μL water droplet. The superhydrophobic cotton sample was also characterized by field emission scanning electron microscopy (FESEM) and energy dispersive X-ray spectroscopy (EDX). The method is simple, eco-friendly and cost-effective and can be applied to large area of cotton fabric materials. It was shown that superhydrophobicity of the fabric was due to the combined effect of surface roughness imparted by zinc hydroxide and the low surface energy of stearic acid.

A simple cost-effective and eco-friendly wet chemical process for the fabrication of superhydrophobic cotton fabrics

Energy Technology Data Exchange (ETDEWEB)

Richard, Edna; Lakshmi, R.V.; Aruna, S.T., E-mail: aruna_reddy@nal.res.in; Basu, Bharathibai J.

2013-07-15

Superhydrophobic surfaces were created on hydrophilic cotton fabrics by a simple wet chemical process. The fabric was immersed in a colloidal suspension of zinc hydroxide followed by subsequent hydrophobization with stearic acid. The wettability of the modified cotton fabric sample was studied by water contact angle (WCA) and water shedding angle (WSA) measurements. The modified cotton fabrics exhibited superhydrophobicity with a WCA of 151° for 8 μL water droplet and a WSA of 5–10° for 40 μL water droplet. The superhydrophobic cotton sample was also characterized by field emission scanning electron microscopy (FESEM) and energy dispersive X-ray spectroscopy (EDX). The method is simple, eco-friendly and cost-effective and can be applied to large area of cotton fabric materials. It was shown that superhydrophobicity of the fabric was due to the combined effect of surface roughness imparted by zinc hydroxide and the low surface energy of stearic acid.

A simple and rapid method to estimate radiocesium in man

International Nuclear Information System (INIS)

Kindl, P.; Steger, F.

1990-09-01

A simple and rapid method for monitoring internal contamination of radiocesium in man was developed. This method is based on measurements of the γ-rays emitted from the muscular parts between the thights by a simple NaJ(Tl)-system. The experimental procedure, the calibration, the estimation of the body activity and results are explained and discussed. (Authors)

Calcium phosphate formation from sea urchin - (brissus latecarinatus via modified mechano-chemical (ultrasonic conversion method

Directory of Open Access Journals (Sweden)

R. Samur

2013-07-01

Full Text Available This study aims to produce apatite structures, such as hydroxyapatite (HA and fluorapatite (FA, from precursor calcium phosphates of biological origin, namely from sea urchin, with mechano-chemical stirring and hot-plating conversion method. The produced materials were heat treated at 800 °C for 4 hours. X-ray diffraction and scanning electron microscopy (SEM studies were conducted. Calcium phosphate phases were developed. The SEM images showed the formation of micro to nano-powders. The experimental results suggest that sea urchin, Brissus latecarinatus skeleton could be an alternative source for the production of various mono or biphasic calcium phosphates with simple and economic mechano-chemical (ultrasonic conversion method.

ZnSe thin films by chemical bath deposition method

Energy Technology Data Exchange (ETDEWEB)

Lokhande, C.D.; Patil, P.S.; Tributsch, H. [Hahn-Meitner-Institute, Bereich Physikalische Chemie, Abt. CS, Glienicker Strasse-100, D-14109 Berlin (Germany); Ennaoui, A. [Hahn-Meitner-Institute, Bereich Physikalische Chemie, Abt. CG, Glienicker Strasse-100, D-14109 Berlin (Germany)

1998-09-04

The ZnSe thin films have been deposited onto glass substrates by the simple chemical bath deposition method using selenourea as a selenide ion source from an aqueous alkaline medium. The effect of Zn ion concentration, bath temperature and deposition time period on the quality and thickness of ZnSe films has been studied. The ZnSe films have been characterized by XRD, TEM, EDAX, TRMC (time-resolved microwave conductivity), optical absorbance and RBS techniques for their structural, compositional, electronic and optical properties. The as-deposited ZnSe films are found to be amorphous, Zn rich with optical band gap, Eg, equal to 2.9 eV

A simple method for estimating the size of nuclei on fractal surfaces

Science.gov (United States)

Zeng, Qiang

2017-10-01

Determining the size of nuclei on complex surfaces remains a big challenge in aspects of biological, material and chemical engineering. Here the author reported a simple method to estimate the size of the nuclei in contact with complex (fractal) surfaces. The established approach was based on the assumptions of contact area proportionality for determining nucleation density and the scaling congruence between nuclei and surfaces for identifying contact regimes. It showed three different regimes governing the equations for estimating the nucleation site density. Nuclei in the size large enough could eliminate the effect of fractal structure. Nuclei in the size small enough could lead to the independence of nucleation site density on fractal parameters. Only when nuclei match the fractal scales, the nucleation site density is associated with the fractal parameters and the size of the nuclei in a coupling pattern. The method was validated by the experimental data reported in the literature. The method may provide an effective way to estimate the size of nuclei on fractal surfaces, through which a number of promising applications in relative fields can be envisioned.

A simple approximation method for dilute Ising systems

International Nuclear Information System (INIS)

Saber, M.

1996-10-01

We describe a simple approximate method to analyze dilute Ising systems. The method takes into consideration the fluctuations of the effective field, and is based on a probability distribution of random variables which correctly accounts for all the single site kinematic relations. It is shown that the simplest approximation gives satisfactory results when compared with other methods. (author). 12 refs, 2 tabs

[Analysis on the accuracy of simple selection method of Fengshi (GB 31)].

Science.gov (United States)

Li, Zhixing; Zhang, Haihua; Li, Suhe

2015-12-01

To explore the accuracy of simple selection method of Fengshi (GB 31). Through the study of the ancient and modern data,the analysis and integration of the acupuncture books,the comparison of the locations of Fengshi (GB 31) by doctors from all dynasties and the integration of modern anatomia, the modern simple selection method of Fengshi (GB 31) is definite, which is the same as the traditional way. It is believed that the simple selec tion method is in accord with the human-oriented thought of TCM. Treatment by acupoints should be based on the emerging nature and the individual difference of patients. Also, it is proposed that Fengshi (GB 31) should be located through the integration between the simple method and body surface anatomical mark.

Two simple cleanup methods combined with LC-MS/MS for quantification of steroid hormones in in vivo and in vitro assays

DEFF Research Database (Denmark)

Weisser, Johan Juhl; Hansen, Cecilie Hurup; Poulsen, Rikke

2016-01-01

Measuring both progestagens, androgens, corticosteroids as well as estrogens with a single method makes it possible to investigate the effects of endocrine-disrupting chemicals (EDCs) on the main pathways in the mammalian steroidogenesis. This paper presents two simple methods for the determination...... of the major steroid hormones in biological matrixes using liquid chromatography tandem mass spectrometry (LC-MS(2)). A novel method was developed for the determination of 14 steroids in the H295R in vitro assay without the need for solid phase extraction (SPE) purification prior to LC-MS(2) analysis....... The in vitro assay was validated by exposing H295R cells to prochloraz for inhibiting steroid hormone secretion and by exposing cells to forskolin for inducing steroid hormone secretion. The developed method fulfills the recommendations for the H295R assay suggested by the OECD. Furthermore, a simple off...

Gallium determination with Rodamina B: a simple method

International Nuclear Information System (INIS)

Queiroz, R.R.U. de.

1981-01-01

A simple method for determining gallium with Rhodamine B, by the modification of the method proposed by Onishi and Sandell. The complex (RH) GaCl 4 is extracted with a mixture benzene-ethylacetate (3:1 V/V), from an aqueous medium 6 M in hydrochloric acid. The interference of foreign ions is studied. (C.G.C.) [pt

A simple and efficient electrochemical reductive method for ...

Indian Academy of Sciences (India)

Administrator

This approach opens up a new, practical and green reducing method to prepare large- scale graphene. ... has the following significant advantages: (1) It is simple to operate. .... The authors thank the National High Technology Research.

Solution of the schrodinger equation in one dimension by simple method for a simple step potential

International Nuclear Information System (INIS)

Ertik, H.

2005-01-01

The coefficients of the transmission and reflection for the simple-step barrier potential were calculated by a simple method. Their values were entirely different from those often encountered in the literature. Especially in the case that the total energy is equal to the barrier potential, the value of 0,20 for the reflection coefficient was obtained whereas this is zero in the literature. This may be considered as an interesting point

Electrochromic and electrochemical capacitive properties of tungsten oxide and its polyaniline nanocomposite films obtained by chemical bath deposition method

CSIR Research Space (South Africa)

Nwanya, AC

2014-05-01

Full Text Available Polyanine and its nanocomposite WO3/PANI films were deposited on fluorine doped tin oxide (FTO) glassslides by simple chemical bath deposition method. The morphology structure of the composite film wasstudied using atomic force microscopy (AFM...

A Simple HPLC Bioanalytical Method for the Determination of ...

African Journals Online (AJOL)

Purpose: To develop a simple, accurate, and precise high performance chromatography (HPLC) method with spectrophotometric detection for the determination of doxorubicin hydrochloride in rat plasma. Methods: Doxorubicin hydrochloride and daunorubicin hydrochloride (internal standard, IS) were separated on a C18 ...

Investigation on structural and optical properties of ZnO film prepared by simple wet chemical method

Science.gov (United States)

Sholehah, Amalia; Mulyadi, Rendi; Haryono, Didied; Muttakin, Imamul; Rusbana, Tb Bahtiar; Mardiyanto

2018-04-01

ZnO thin layer has a broad potential application in electronic and optoelectronic devices. In this study, vertically align ZnO layers were deposited on ITO glass using wet chemistry method. The seed layers were prepared using electrodeposition technique at 3°C. The growing process was carried out using chemical bath deposition at 90°C. To improve the structural properties, two different hydrothermal treatment variations were applied separately. From the experiment, it is shown that the hydrothermal process using N2 gas has given the best result, with average diameter, crystallite size, and band-gap energy of 68.83 nm; 56.37 nm; and 3.16 eV, respectively.

Toxicity assessment of industrial chemicals and airborne contaminants: transition from in vivo to in vitro test methods: a review.

Science.gov (United States)

Bakand, S; Winder, C; Khalil, C; Hayes, A

2005-12-01

Exposure to occupational and environmental contaminants is a major contributor to human health problems. Inhalation of gases, vapors, aerosols, and mixtures of these can cause a wide range of adverse health effects, ranging from simple irritation to systemic diseases. Despite significant achievements in the risk assessment of chemicals, the toxicological database, particularly for industrial chemicals, remains limited. Considering there are approximately 80,000 chemicals in commerce, and an extremely large number of chemical mixtures, in vivo testing of this large number is unachievable from both economical and practical perspectives. While in vitro methods are capable of rapidly providing toxicity information, regulatory agencies in general are still cautious about the replacement of whole-animal methods with new in vitro techniques. Although studying the toxic effects of inhaled chemicals is a complex subject, recent studies demonstrate that in vitro methods may have significant potential for assessing the toxicity of airborne contaminants. In this review, current toxicity test methods for risk evaluation of industrial chemicals and airborne contaminants are presented. To evaluate the potential applications of in vitro methods for studying respiratory toxicity, more recent models developed for toxicity testing of airborne contaminants are discussed.

Comparison of Chemical and Physical-chemical Wastewater Discoloring Methods

Directory of Open Access Journals (Sweden)

Durašević, V.

2007-11-01

Full Text Available Today's chemical and physical-chemical wastewater discoloration methods do not completely meet demands regarding degree of discoloration. In this paper discoloration was performed using Fenton (FeSO4 . 7 H2O + H2O2 + H2SO4 and Fenton-like (FeCl3 . 6 H2O + H2O2 + HCOOH chemical methods and physical-chemical method of coagulation/flocculation (using poly-electrolyte (POEL combining anion active coagulant (modified poly-acrylamides and cationic flocculant (product of nitrogen compounds in combination with adsorption on activated carbon. Suitability of aforementioned methods was investigated on reactive and acid dyes, regarding their most common use in the textile industry. Also, investigations on dyes of different chromogen (anthraquinone, phthalocyanine, azo and xanthene were carried out in order to determine the importance of molecular spatial structure. Oxidative effect of Fenton and Fenton-like reagents resulted in decomposition of colored chromogen and high degree of discoloration. However, the problem is the inability of adding POEL in stechiometrical ratio (also present in physical-chemical methods, when the phenomenon of overdosing coagulants occurs in order to obtain a higher degree of discoloration, creating a potential danger of burdening water with POEL. Input and output water quality was controlled through spectrophotometric measurements and standard biological parameters. In addition, part of the investigations concerned industrial wastewaters obtained from dyeing cotton materials using reactive dye (C. I. Reactive Blue 19, a process that demands the use of vast amounts of electrolytes. Also, investigations of industrial wastewaters was labeled as a crucial step carried out in order to avoid serious misassumptions and false conclusions, which may arise if dyeing processes are only simulated in the laboratory.

A simple method for multiday imaging of slice cultures.

Science.gov (United States)

Seidl, Armin H; Rubel, Edwin W

2010-01-01

The organotypic slice culture (Stoppini et al. A simple method for organotypic cultures of nervous tissue. 1991;37:173-182) has become the method of choice to answer a variety of questions in neuroscience. For many experiments, however, it would be beneficial to image or manipulate a slice culture repeatedly, for example, over the course of many days. We prepared organotypic slice cultures of the auditory brainstem of P3 and P4 mice and kept them in vitro for up to 4 weeks. Single cells in the auditory brainstem were transfected with plasmids expressing fluorescent proteins by way of electroporation (Haas et al. Single-cell electroporation for gene transfer in vivo. 2001;29:583-591). The culture was then placed in a chamber perfused with oxygenated ACSF and the labeled cell imaged with an inverted wide-field microscope repeatedly for multiple days, recording several time-points per day, before returning the slice to the incubator. We describe a simple method to image a slice culture preparation during the course of multiple days and over many continuous hours, without noticeable damage to the tissue or photobleaching. Our method uses a simple, inexpensive custom-built insulator constructed around the microscope to maintain controlled temperature and uses a perfusion chamber as used for in vitro slice recordings. (c) 2009 Wiley-Liss, Inc.

Fusion of microlitre water-in-oil droplets for simple, fast and green chemical assays.

Science.gov (United States)

Chiu, S-H; Urban, P L

2015-08-07

A simple format for microscale chemical assays is proposed. It does not require the use of test tubes, microchips or microtiter plates. Microlitre-range (ca. 0.7-5.0 μL) aqueous droplets are generated by a commercial micropipette in a non-polar matrix inside a Petri dish. When two droplets are pipetted nearby, they spontaneously coalesce within seconds, priming a chemical reaction. Detection of the reaction product is accomplished by colorimetry, spectrophotometry, or fluorimetry using simple light-emitting diode (LED) arrays as the sources of monochromatic light, while chemiluminescence detection of the analytes present in single droplets is conducted in the dark. A smartphone camera is used as the detector. The limits of detection obtained for the developed in-droplet assays are estimated to be: 1.4 nmol (potassium permanganate by colorimetry), 1.4 pmol (fluorescein by fluorimetry), and 580 fmol (sodium hypochlorite by chemiluminescence detection). The format has successfully been used to monitor the progress of chemical and biochemical reactions over time with sub-second resolution. A semi-quantitative analysis of ascorbic acid using Tillman's reagent is presented. A few tens of individual droplets can be scanned in parallel. Rapid switching of the LED light sources with different wavelengths enables a spectral analysis of multiple droplets. Very little solid waste is produced. The assay matrix is readily recycled, thus the volume of liquid waste produced each time is also very small (typically, 1-10 μL per analysis). Various water-immiscible translucent liquids can be used as the reaction matrix: including silicone oil, 1-octanol as well as soybean cooking oil.

Simple Synthesis Method for Alumina Nanoparticle

Directory of Open Access Journals (Sweden)

Daniel Damian

2017-11-01

Full Text Available Globally, the human population steady increase, expansion of urban areas, excessive industrialization including in agriculture, caused not only decrease to depletion of non-renewable resources, a rapid deterioration of the environment with negative impact on water quality, soil productivity and of course quality of life in general. This paper aims to prepare size controlled nanoparticles of aluminum oxide using a simple synthesis method. The morphology and dimensions of nanomaterial was investigated using modern analytical techniques: SEM/EDAX and XRD spectroscopy.

Percutaneous Method of Management of Simple Bone Cyst

Directory of Open Access Journals (Sweden)

O. P. Lakhwani

2013-01-01

Full Text Available Introduction. Simple bone cyst or unicameral bone cysts are benign osteolytic lesions seen in metadiaphysis of long bones in growing children. Various treatment modalities with variable outcomes have been described in the literature. The case report illustrates the surgical technique of minimally invasive method of treatment. Case Study. A 14-year-old boy was diagnosed as active simple bone cyst proximal humerus with pathological fracture. The patient was treated by minimally invasive percutaneous curettage with titanium elastic nail (TENS and allogenic bone grafting mixed with bone marrow under image intensifier guidance. Results. Pathological fracture was healed and allograft filled in the cavity was well taken up. The patient achieved full range of motion with successful outcome. Conclusion. Minimally invasive percutaneous method using elastic intramedullary nail gives benefit of curettage cyst decompression and stabilization of fracture. Allogenic bone graft fills the cavity and healing of lesion by osteointegration. This method may be considered with advantage of minimally invasive technique in treatment of benign cystic lesions of bone, and the level of evidence was therapeutic level V.

Percutaneous Method of Management of Simple Bone Cyst

Science.gov (United States)

Lakhwani, O. P.

2013-01-01

Introduction. Simple bone cyst or unicameral bone cysts are benign osteolytic lesions seen in metadiaphysis of long bones in growing children. Various treatment modalities with variable outcomes have been described in the literature. The case report illustrates the surgical technique of minimally invasive method of treatment. Case Study. A 14-year-old boy was diagnosed as active simple bone cyst proximal humerus with pathological fracture. The patient was treated by minimally invasive percutaneous curettage with titanium elastic nail (TENS) and allogenic bone grafting mixed with bone marrow under image intensifier guidance. Results. Pathological fracture was healed and allograft filled in the cavity was well taken up. The patient achieved full range of motion with successful outcome. Conclusion. Minimally invasive percutaneous method using elastic intramedullary nail gives benefit of curettage cyst decompression and stabilization of fracture. Allogenic bone graft fills the cavity and healing of lesion by osteointegration. This method may be considered with advantage of minimally invasive technique in treatment of benign cystic lesions of bone, and the level of evidence was therapeutic level V. PMID:23819089

A simple method for α determination

International Nuclear Information System (INIS)

Ho Manh Dung; Seung Yeon Cho

2003-01-01

The a term is a primary parameter that is used to indicate the deviation of the epithermal neutron distribution in the k 0 -standardization method of neutron activation analysis, k 0 -NAA. The calculation of a using a mathematical procedure is a challenge for some researchers. The calculation of a by the 'bare-triple monitor' method is possible using the dedicated commercial software KAYZERO R /SOLCOI R . However, when this software is not available in the laboratory it is possible to carry out the calculation of a applying a simple iterative linear regression using any spreadsheets. This approach is described. The experimental data used in the example were obtained by the irradiation of a set of suitable monitors in the NAA no.1 irradiation channel of the HANARO research reactor (KAERI, Korea). The results obtained by this iterative linear regression method agree well with the results calculated by the validated mathematical method. (author)

Photochemical binding of photoallergens to human serum albumin: a simple in vitro method for screening potential photoallergens

International Nuclear Information System (INIS)

Barratt, M.D.; Brown, K.R.

1985-01-01

A simple procedure employing UV spectroscopy is described for testing the ability of chemicals to form covalent conjugates with proteins after irradiation with the appropriate wavelength of light. A range of known photoallergens of widely differing structure has been tested using this procedure; results of these experiments, together with evidence from the scientific literature, provide a correlation between compounds known to be photoallergens and their ability to form covalent conjugates with proteins on irradiation with the appropriate wavelength of light. The method is proposed as an in vitro screening procedure for potential photoallergens. (Auth.)

Fabrication and Characterization of Zinc Sulfide Nanoparticles and Nanocomposites Prepared via a Simple Chemical Precipitation Method

Directory of Open Access Journals (Sweden)

Kambiz Hedayati

2016-07-01

Full Text Available In this research zinc sulfide (ZnS nanoparticles and nanocomposites powders were prepared by chemical precipitation method using zinc acetate and various sulfur sources. The ZnS nanoparticles were characterized by X-ray diffraction, scanning electron microscopy, ultraviolet-visible and fourier transform infra-red. The structure of nanoparticles was studied using X-ray diffraction pattern. The crystallite size of ZnS nanoparticles was calculated by Debye–Scherrer formula. Morphology of nano-crystals was observed and investigated using the scanning electron microscopy. The grain size of zinc sulfide nanoparticles were in suitable agreement with the crystalline size calculated by X-ray diffraction results. The optical properties of particles were studied with ultraviolet-visible absorption spectrum.

Simple equation method for nonlinear partial differential equations and its applications

Directory of Open Access Journals (Sweden)

Taher A. Nofal

2016-04-01

Full Text Available In this article, we focus on the exact solution of the some nonlinear partial differential equations (NLPDEs such as, Kodomtsev–Petviashvili (KP equation, the (2 + 1-dimensional breaking soliton equation and the modified generalized Vakhnenko equation by using the simple equation method. In the simple equation method the trial condition is the Bernoulli equation or the Riccati equation. It has been shown that the method provides a powerful mathematical tool for solving nonlinear wave equations in mathematical physics and engineering problems.

Enhancement of Thermoelectric Properties of PEDOT:PSS and Tellurium-PEDOT:PSS Hybrid Composites by Simple Chemical Treatment

Science.gov (United States)

Jin Bae, Eun; Hun Kang, Young; Jang, Kwang-Suk; Yun Cho, Song

2016-01-01

The thermoelectric properties of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and tellurium-PEDOT:PSS (Te-PEDOT:PSS) hybrid composites were enhanced via simple chemical treatment. The performance of thermoelectric materials is determined by their electrical conductivity, thermal conductivity, and Seebeck coefficient. Significant enhancement of the electrical conductivity of PEDOT:PSS and Te-PEDOT:PSS hybrid composites from 787.99 and 11.01 to 4839.92 and 334.68 S cm-1, respectively was achieved by simple chemical treatment with H2SO4. The power factor of the developed materials could be effectively tuned over a very wide range depending on the concentration of the H2SO4 solution used in the chemical treatment. The power factors of the developed thermoelectric materials were optimized to 51.85 and 284 μW m-1 K-2, respectively, which represent an increase of four orders of magnitude relative to the corresponding parameters of the untreated thermoelectric materials. Using the Te-PEDOT:PSS hybrid composites, a flexible thermoelectric generator that could be embedded in textiles was fabricated by a printing process. This thermoelectric array generates a thermoelectric voltage of 2 mV using human body heat.

A simple finite element method for linear hyperbolic problems

International Nuclear Information System (INIS)

Mu, Lin; Ye, Xiu

2017-01-01

Here, we introduce a simple finite element method for solving first order hyperbolic equations with easy implementation and analysis. Our new method, with a symmetric, positive definite system, is designed to use discontinuous approximations on finite element partitions consisting of arbitrary shape of polygons/polyhedra. Error estimate is established. Extensive numerical examples are tested that demonstrate the robustness and flexibility of the method.

Chemically Roughened Solid Silver: A Simple, Robust and Broadband SERS Substrate

Directory of Open Access Journals (Sweden)

Shavini Wijesuriya

2016-10-01

Full Text Available Surface-enhanced Raman spectroscopy (SERS substrates manufactured using complex nano-patterning techniques have become the norm. However, their cost of manufacture makes them unaffordable to incorporate into most biosensors. The technique shown in this paper is low-cost, reliable and highly sensitive. Chemical etching of solid Ag metal was used to produce simple, yet robust SERS substrates with broadband characteristics. Etching with ammonium hydroxide (NH4OH and nitric acid (HNO3 helped obtain roughened Ag SERS substrates. Scanning electron microscopy (SEM and interferometry were used to visualize and quantify surface roughness. Flattened Ag wires had inherent, but non-uniform roughness having peaks and valleys in the microscale. NH4OH treatment removed dirt and smoothened the surface, while HNO3 treatment produced a flake-like morphology with visibly more surface roughness features on Ag metal. SERS efficacy was tested using 4-methylbenzenethiol (MBT. The best SERS enhancement for 1 mM MBT was observed for Ag metal etched for 30 s in NH4OH followed by 10 s in HNO3. Further, MBT could be quantified with detection limits of 1 pM and 100 µM, respectively, using 514 nm and 1064 nm Raman spectrometers. Thus, a rapid and less energy intensive method for producing solid Ag SERS substrate and its efficacy in analyte sensing was demonstrated.

A simple and cost-effective method for fabrication of integrated electronic-microfluidic devices using a laser-patterned PDMS layer

KAUST Repository

Li, Ming

2011-12-03

We report a simple and cost-effective method for fabricating integrated electronic-microfluidic devices with multilayer configurations. A CO 2 laser plotter was employed to directly write patterns on a transferred polydimethylsiloxane (PDMS) layer, which served as both a bonding and a working layer. The integration of electronics in microfluidic devices was achieved by an alignment bonding of top and bottom electrode-patterned substrates fabricated with conventional lithography, sputtering and lift-off techniques. Processes of the developed fabrication method were illustrated. Major issues associated with this method as PDMS surface treatment and characterization, thickness-control of the transferred PDMS layer, and laser parameters optimization were discussed, along with the examination and testing of bonding with two representative materials (glass and silicon). The capability of this method was further demonstrated by fabricating a microfluidic chip with sputter-coated electrodes on the top and bottom substrates. The device functioning as a microparticle focusing and trapping chip was experimentally verified. It is confirmed that the proposed method has many advantages, including simple and fast fabrication process, low cost, easy integration of electronics, strong bonding strength, chemical and biological compatibility, etc. © Springer-Verlag 2011.

Few-layer graphene growth from polystyrene as solid carbon source utilizing simple APCVD method

Science.gov (United States)

Ahmadi, Shahrokh; Afzalzadeh, Reza

2016-07-01

This research article presents development of an economical, simple, immune and environment friendly process to grow few-layer graphene by controlling evaporation rate of polystyrene on copper foil as catalyst and substrate utilizing atmospheric pressure chemical vapor deposition (APCVD) method. Evaporation rate of polystyrene depends on molecular structure, amount of used material and temperature. We have found controlling rate of evaporation of polystyrene by controlling the source temperature is easier than controlling the material weight. Atomic force microscopy (AFM) as well as Raman Spectroscopy has been used for characterization of the layers. The frequency of G‧ to G band ratio intensity in some samples varied between 0.8 and 1.6 corresponding to few-layer graphene. Topography characterization by atomic force microscopy confirmed Raman results.

Simple Calculation Programs for Biology Methods in Molecular ...

Indian Academy of Sciences (India)

First page Back Continue Last page Overview Graphics. Simple Calculation Programs for Biology Methods in Molecular Biology. GMAP: A program for mapping potential restriction sites. RE sites in ambiguous and non-ambiguous DNA sequence; Minimum number of silent mutations required for introducing a RE sites; Set ...

Synchronization and Arrest of the Budding Yeast Cell Cycle Using Chemical and Genetic Methods.

Science.gov (United States)

Rosebrock, Adam P

2017-01-03

The cell cycle of budding yeast can be arrested at specific positions by different genetic and chemical methods. These arrests enable study of cell cycle phase-specific phenotypes that would be missed during examination of asynchronous cultures. Some methods for arrest are reversible, with kinetics that enable release of cells back into a synchronous cycling state. Benefits of chemical and genetic methods include scalability across a large range of culture sizes from a few milliliters to many liters, ease of execution, the absence of specific equipment requirements, and synchronization and release of the entire culture. Of note, cell growth and division are decoupled during arrest and block-release experiments. Cells will continue transcription, translation, and accumulation of protein while arrested. If allowed to reenter the cell cycle, cells will do so as a population of mixed, larger-than-normal cells. Despite this important caveat, many aspects of budding yeast physiology are accessible using these simple chemical and genetic tools. Described here are methods for the block and release of cells in G 1 phase and at the M/G 1 transition using α-factor mating pheromone and the temperature-sensitive cdc15-2 allele, respectively, in addition to methods for arresting the cell cycle in early S phase and at G 2 /M by using hydroxyurea and nocodazole, respectively. © 2017 Cold Spring Harbor Laboratory Press.

Synthesis of ZnO nanopencils using wet chemical method and its investigation as LPG sensor

International Nuclear Information System (INIS)

Shimpi, Navinchandra G.; Jain, Shilpa; Karmakar, Narayan; Shah, Akshara; Kothari, D.C.; Mishra, Satyendra

2016-01-01

Highlights: • Synthesis using a simple and cost-effective wet chemical process. • Uniform, monodispersed and pure nanoparticles. • Pencil shaped rods with sharp tips. • Understanding of Growth mechanism. • Efficient LPG sensing with high response. • Morphology dependent sensing. - Abstract: ZnO nanopencils (NPCs) were prepared by a novel wet chemical process, using triethanolamine (TEA) as a mild base, which is relatively simple and cost effective method as compared to hydrothermal method. ZnO NPCs were characterized using powder X-ray diffraction (XRD), Fourier Transform Infra-Red (FTIR) spectroscopy in mid-IR and far-IR regions, X-ray Photoelectron Spectroscopy (XPS), UV–vis (UV–vis) absorption spectroscopy, room temperature Photoluminescence (PL) spectroscopy and Field Emission Scanning Electron Microscopy (FESEM). ZnO NPCs obtained, were highly pure, uniform and monodispersed.XRD pattern indicated hexagonal unit cell structure with preferred orientation along the c-axis. Sensing behaviour of ZnO NPCs was studied towards Liquefied Petroleum Gas (LPG) at different operating temperatures. The study shows that ZnO NPCs were most sensitive and promising candidate for detection of LPG at 250 °C with gas sensitivity > 60%. The high response towards LPG is due to high surface area of ZnO NPCs and their parallel alignment.

Synthesis of ZnO nanopencils using wet chemical method and its investigation as LPG sensor

Energy Technology Data Exchange (ETDEWEB)

Shimpi, Navinchandra G., E-mail: navin_shimpi@rediffmail.com [Department of Chemistry, University of Mumbai, Santacruz (East), Mumbai-400098 (India); Jain, Shilpa [Department of Chemistry, University of Mumbai, Santacruz (East), Mumbai-400098 (India); Karmakar, Narayan [Department of Physics, University of Mumbai, Santacruz (East), Mumbai-400098 (India); Shah, Akshara [Department of Chemistry, University of Mumbai, Santacruz (East), Mumbai-400098 (India); Kothari, D.C. [Department of Physics, University of Mumbai, Santacruz (East), Mumbai-400098 (India); National Centre for Nanosciences & Nanotechnology, University of Mumbai, Santacruz (East), Mumbai-400098 (India); Mishra, Satyendra [University Institute of Chemical Technology, North Maharashtra University, Jalgaon (India)

2016-12-30

Highlights: • Synthesis using a simple and cost-effective wet chemical process. • Uniform, monodispersed and pure nanoparticles. • Pencil shaped rods with sharp tips. • Understanding of Growth mechanism. • Efficient LPG sensing with high response. • Morphology dependent sensing. - Abstract: ZnO nanopencils (NPCs) were prepared by a novel wet chemical process, using triethanolamine (TEA) as a mild base, which is relatively simple and cost effective method as compared to hydrothermal method. ZnO NPCs were characterized using powder X-ray diffraction (XRD), Fourier Transform Infra-Red (FTIR) spectroscopy in mid-IR and far-IR regions, X-ray Photoelectron Spectroscopy (XPS), UV–vis (UV–vis) absorption spectroscopy, room temperature Photoluminescence (PL) spectroscopy and Field Emission Scanning Electron Microscopy (FESEM). ZnO NPCs obtained, were highly pure, uniform and monodispersed.XRD pattern indicated hexagonal unit cell structure with preferred orientation along the c-axis. Sensing behaviour of ZnO NPCs was studied towards Liquefied Petroleum Gas (LPG) at different operating temperatures. The study shows that ZnO NPCs were most sensitive and promising candidate for detection of LPG at 250 °C with gas sensitivity > 60%. The high response towards LPG is due to high surface area of ZnO NPCs and their parallel alignment.

A SIMPLE METHOD FOR THE EXTRACTION AND QUANTIFICATION OF PHOTOPIGMENTS FROM SYMBIODINIUM SPP.

Science.gov (United States)

John E. Rogers and Dragoslav Marcovich. Submitted. Simple Method for the Extraction and Quantification of Photopigments from Symbiodinium spp.. Limnol. Oceanogr. Methods. 19 p. (ERL,GB 1192). We have developed a simple, mild extraction procedure using methanol which, when...

A Simple and Direct LC-MS Method for Determination of Genotoxic Impurity Hydroxylamine in Pharmaceutical compounds.

Science.gov (United States)

Kumar, Thangarathinam; Ramya, Mohandass; Srinivasan, Viswanathan; Xavier, N

2017-08-01

Hydroxylamine is a known genotoxic impurity compound that needs to be controlled down to ppm level in pharmaceutical processes. It is difficult to detect using conventional analytical techniques due to its physio-chemical properties like lack of chromophore, low molecular weight, absence of carbon atom and high polarity. In addition to that, analysis of the pharmaceutical samples encounters considerable obstruction from matrix components that greatly overshadow the response of hydroxylamine. This study describes a simple, sensitive and direct Liquid Chromatographic-Mass Spectrometric method (LC-MS) for detection of hydroxylamine in pharmaceutical compounds. The LC-MS method was detected up to 0.008 ppm of hydroxylamine with S/N > 3.0 and quantified up to 0.025 ppm of hydroxylamine with S/N ratio >10.0. This validated method can be applied as a generic method to detect the hydroxylamine for pharmaceutical process control and drug substance release. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

A phenomenological model for the structure-composition relationship of the high Tc cuprates based on simple chemical principles

International Nuclear Information System (INIS)

Alarco, J.A.; Talbot, P.C.

2012-01-01

A simple phenomenological model for the relationship between structure and composition of the high Tc cuprates is presented. The model is based on two simple crystal chemistry principles: unit cell doping and charge balance within unit cells. These principles are inspired by key experimental observations of how the materials accommodate large deviations from stoichiometry. Consistent explanations for significant HTSC properties can be explained without any additional assumptions while retaining valuable insight for geometric interpretation. Combining these two chemical principles with a review of Crystal Field Theory (CFT) or Ligand Field Theory (LFT), it becomes clear that the two oxidation states in the conduction planes (typically d 8 and d 9 ) belong to the most strongly divergent d-levels as a function of deformation from regular octahedral coordination. This observation offers a link to a range of coupling effects relating vibrations and spin waves through application of Hund’s rules. An indication of this model’s capacity to predict physical properties for HTSC is provided and will be elaborated in subsequent publications. Simple criteria for the relationship between structure and composition in HTSC systems may guide chemical syntheses within new material systems.

A simple and secure method to fix laparoscopic trocars in children.

Science.gov (United States)

Yip, K F; Tam, P K H; Li, M K W

2006-04-01

We introduce a simple method of fixing trocars to the abdominal wall in children. Before anchoring the trocar, a piece of Tegaderm polyurethrane adhesive (3M Healthcare, St. Paul, Minnesota) is attached to the trocar. A silk stitch is anchored to neighboring skin, and then transfixed over the shaft of the trocar through the adhesive. Both inward and outward movement of the trocar can be restrained. This method is simple, fast, secure, and can be applied to trocars of any size.

The efficiency of the centroid method compared to a simple average

DEFF Research Database (Denmark)

Eskildsen, Jacob Kjær; Kristensen, Kai; Nielsen, Rikke

Based on empirical data as well as a simulation study this paper gives recommendations with respect to situations wheere a simple avarage of the manifest indicators can be used as a close proxy for the centroid method and when it cannot.......Based on empirical data as well as a simulation study this paper gives recommendations with respect to situations wheere a simple avarage of the manifest indicators can be used as a close proxy for the centroid method and when it cannot....

A simple and selective method for the separation of Cu radioisotopes from nickel

Energy Technology Data Exchange (ETDEWEB)

Fan Xianfeng [School of Physics and Astronomy, University of Birmingham, B15 2TT Birmingham (United Kingdom)]. E-mail: x.fan@bham.ac.uk; Parker, David J. [School of Physics and Astronomy, University of Birmingham, B15 2TT Birmingham (United Kingdom); Smith, Mike D. [School of Physics and Astronomy, University of Birmingham, B15 2TT Birmingham (United Kingdom); Ingram, Andy [School of Physics and Astronomy, University of Birmingham, B15 2TT Birmingham (United Kingdom); Yang Zhufang [School of Physics and Astronomy, University of Birmingham, B15 2TT Birmingham (United Kingdom); Seville, Jonathan P.K. [School of Physics and Astronomy, University of Birmingham, B15 2TT Birmingham (United Kingdom)

2006-10-15

Separation of copper radioisotopes from a nickel target is normally performed using solvent extraction or anion exchange rather than using cationic exchange. A commonly held opinion is that cationic exchangers have very similar thermodynamic complexation constants for metallic ions with identical charges, therefore making the separation very difficult or impossible. The results presented in this article indicate that the selectivity of Chelex-100 (a cationic ion exchanger) for Cu radioisotope and Ni ions not only depends on the thermodynamic complexation constant in the resin but also markedly varies with the concentration of mobile H{sup +}. In our developed method, separation of copper radioisotopes from a nickel target was fulfilled in a column filled with Chelex-100 via controlling the HNO{sub 3} concentration of the eluent, and the separation is much more effective, simple and economical in comparison with the common method of anion exchange. For an irradiated nickel target with 650 mg Ni, after separation, the loss of Cu radioisotopes in the nickel portion was reduced from 30% to 0.33% of the total initial radioactivity and the nickel mixed into the radioactive products was reduced from 9.5 to 0.5 mg. This significant improvement will make subsequent labeling much easier and reduce consumption of chelating agents and other chemicals during labeling. If the labeled agent is used in human medical applications, the developed method will significantly decrease the uptake of Ni and chelating agents by patients, therefore reducing both the stress on human body associated with clearing the chemicals from blood and tissue and the risk of various types of acute and chronic disorder due to exposure to Ni.

Chemical kinetics of gas reactions

CERN Document Server

Kondrat'Ev, V N

2013-01-01

Chemical Kinetics of Gas Reactions explores the advances in gas kinetics and thermal, photochemical, electrical discharge, and radiation chemical reactions. This book is composed of 10 chapters, and begins with the presentation of general kinetic rules for simple and complex chemical reactions. The next chapters deal with the experimental methods for evaluating chemical reaction mechanisms and some theories of elementary chemical processes. These topics are followed by discussions on certain class of chemical reactions, including unimolecular, bimolecular, and termolecular reactions. The rema

A simple statistical method for catch comparison studies

DEFF Research Database (Denmark)

Holst, René; Revill, Andrew

2009-01-01

For analysing catch comparison data, we propose a simple method based on Generalised Linear Mixed Models (GLMM) and use polynomial approximations to fit the proportions caught in the test codend. The method provides comparisons of fish catch at length by the two gears through a continuous curve...... with a realistic confidence band. We demonstrate the versatility of this method, on field data obtained from the first known testing in European waters of the Rhode Island (USA) 'Eliminator' trawl. These data are interesting as they include a range of species with different selective patterns. Crown Copyright (C...

Spectroscopic Chemical Analysis Methods and Apparatus

Science.gov (United States)

Hug, William F. (Inventor); Reid, Ray D. (Inventor); Bhartia, Rohit (Inventor); Lane, Arthur L. (Inventor)

2018-01-01

Spectroscopic chemical analysis methods and apparatus are disclosed which employ deep ultraviolet (e.g. in the 200 nm to 300 nm spectral range) electron beam pumped wide bandgap semiconductor lasers, incoherent wide bandgap semiconductor light emitting devices, and hollow cathode metal ion lasers to perform non-contact, non-invasive detection of unknown chemical analytes. These deep ultraviolet sources enable dramatic size, weight and power consumption reductions of chemical analysis instruments. In some embodiments, Raman spectroscopic detection methods and apparatus use ultra-narrow-band angle tuning filters, acousto-optic tuning filters, and temperature tuned filters to enable ultra-miniature analyzers for chemical identification. In some embodiments Raman analysis is conducted along with photoluminescence spectroscopy (i.e. fluorescence and/or phosphorescence spectroscopy) to provide high levels of sensitivity and specificity in the same instrument.

Chemical microreactor and method thereof

Science.gov (United States)

Morse, Jeffrey D [Martinez, CA; Jankowski, Alan [Livermore, CA

2011-08-09

A method for forming a chemical microreactor includes forming at least one capillary microchannel in a substrate having at least one inlet and at least one outlet, integrating at least one heater into the chemical microreactor, interfacing the capillary microchannel with a liquid chemical reservoir at the inlet of the capillary microchannel, and interfacing the capillary microchannel with a porous membrane near the outlet of the capillary microchannel, the porous membrane being positioned beyond the outlet of the capillary microchannel, wherein the porous membrane has at least one catalyst material imbedded therein.

PbO networks composed of single crystalline nanosheets synthesized by a facile chemical precipitation method

Energy Technology Data Exchange (ETDEWEB)

Samberg, Joshua P. [Department of Materials Science and Engineering, North Carolina State University, 911 Partners Way, Engineering Building I, Raleigh, NC 27695-7907 (United States); Kajbafvala, Amir, E-mail: amir.kajbafvala@gmail.com [Department of Materials Science and Engineering, North Carolina State University, 911 Partners Way, Engineering Building I, Raleigh, NC 27695-7907 (United States); Koolivand, Amir [Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, NC 27695 (United States)

2014-03-01

Graphical abstract: - Highlights: • Synthesis of PbO networks through a simple chemical precipitation route. • The synthesis method is rapid and low-cost. • Each network is composed of single crystalline PbO nanosheets. • A possible growth mechanism is proposed for synthesized PbO networks. - Abstract: For the field of energy storage, nanostructured lead oxide (PbO) shows immense potential for increased specific energy and deep discharge for lead acid battery technologies. In this work, PbO networks composed of single crystalline nanosheets were synthesized utilizing a simple, low cost and rapid chemical precipitation method. The PbO networks were prepared in a single reaction vessel from starting reagents of lead acetate dehydrate, ammonium hydroxide and deionized water. Lead acetate dehydrate was chosen as a reagent, as opposed to lead nitrate, to eliminate the possibility of nitrate contamination of the final product. X-ray diffraction (XRD) analysis, high resolution scanning electron microscopy (HRSEM) and high resolution transmission electron microscopy (HRTEM) analysis were used to characterize the synthesized PbO networks. The reproducible method described herein synthesized pure β-PbO (massicot) powders, with no byproducts. A possible formation mechanism for these PbO networks is proposed. The growth is found to proceed predominately in the 〈1 1 1〉 and 〈2 0 0〉 directions while being limited in the 〈0 1 1〉 direction.

PbO networks composed of single crystalline nanosheets synthesized by a facile chemical precipitation method

International Nuclear Information System (INIS)

Samberg, Joshua P.; Kajbafvala, Amir; Koolivand, Amir

2014-01-01

Graphical abstract: - Highlights: • Synthesis of PbO networks through a simple chemical precipitation route. • The synthesis method is rapid and low-cost. • Each network is composed of single crystalline PbO nanosheets. • A possible growth mechanism is proposed for synthesized PbO networks. - Abstract: For the field of energy storage, nanostructured lead oxide (PbO) shows immense potential for increased specific energy and deep discharge for lead acid battery technologies. In this work, PbO networks composed of single crystalline nanosheets were synthesized utilizing a simple, low cost and rapid chemical precipitation method. The PbO networks were prepared in a single reaction vessel from starting reagents of lead acetate dehydrate, ammonium hydroxide and deionized water. Lead acetate dehydrate was chosen as a reagent, as opposed to lead nitrate, to eliminate the possibility of nitrate contamination of the final product. X-ray diffraction (XRD) analysis, high resolution scanning electron microscopy (HRSEM) and high resolution transmission electron microscopy (HRTEM) analysis were used to characterize the synthesized PbO networks. The reproducible method described herein synthesized pure β-PbO (massicot) powders, with no byproducts. A possible formation mechanism for these PbO networks is proposed. The growth is found to proceed predominately in the 〈1 1 1〉 and 〈2 0 0〉 directions while being limited in the 〈0 1 1〉 direction

A simple three dimensional wide-angle beam propagation method

Science.gov (United States)

Ma, Changbao; van Keuren, Edward

2006-05-01

The development of three dimensional (3-D) waveguide structures for chip scale planar lightwave circuits (PLCs) is hampered by the lack of effective 3-D wide-angle (WA) beam propagation methods (BPMs). We present a simple 3-D wide-angle beam propagation method (WA-BPM) using Hoekstra’s scheme along with a new 3-D wave equation splitting method. The applicability, accuracy and effectiveness of our method are demonstrated by applying it to simulations of wide-angle beam propagation and comparing them with analytical solutions.

A simple graphical method for measuring inherent safety

International Nuclear Information System (INIS)

Gupta, J.P.; Edwards, David W.

2003-01-01

Inherently safer design (ISD) concepts have been with us for over two decades since their elaboration by Kletz [Chem. Ind. 9 (1978) 124]. Interest has really taken off globally since the early nineties after several major mishaps occurred during the eighties (Bhopal, Mexico city, Piper-alfa, Philips Petroleum, to name a few). Academic and industrial research personnel have been actively involved into devising inherently safer ways of production. The regulatory bodies have also shown deep interest since ISD makes the production safer and hence their tasks easier. Research funding has also been forthcoming for new developments as well as for demonstration projects. A natural question that arises is as to how to measure ISD characteristics of a process? Several researchers have worked on this [Trans. IChemE, Process Safety Environ. Protect. B 71 (4) (1993) 252; Inherent safety in process plant design, Ph.D. Thesis, VTT Publication Number 384, Helsinki University of Technology, Espoo, Finland, 1999; Proceedings of the Mary Kay O'Connor Process Safety Center Symposium, 2001, p. 509]. Many of the proposed methods are very elegant, yet too involved for easy adoption by the industry which is scared of yet another safety analysis regime. In a recent survey [Trans. IChemE, Process Safety Environ. Prog. B 80 (2002) 115], companies desired a rather simple method to measure ISD. Simplification is also an important characteristic of ISD. It is therefore desirable to have a simple ISD measurement procedure. The ISD measurement procedure proposed in this paper can be used to differentiate between two or more processes for the same end product. The salient steps are: Consider each of the important parameters affecting the safety (e.g., temperature, pressure, toxicity, flammability, etc.) and the range of possible values these parameters can have for all the process routes under consideration for an end product. Plot these values for each step in each process route and compare. No

Ion transport by gating voltage to nanopores produced via metal-assisted chemical etching method

Science.gov (United States)

Van Toan, Nguyen; Inomata, Naoki; Toda, Masaya; Ono, Takahito

2018-05-01

In this work, we report a simple and low-cost way to create nanopores that can be employed for various applications in nanofluidics. Nano sized Ag particles in the range from 1 to 20 nm are formed on a silicon substrate with a de-wetting method. Then the silicon nanopores with an approximate 15 nm average diameter and 200 μm height are successfully produced by the metal-assisted chemical etching method. In addition, electrically driven ion transport in the nanopores is demonstrated for nanofluidic applications. Ion transport through the nanopores is observed and could be controlled by an application of a gating voltage to the nanopores.

Construction of simple quartz crystal microbalance

Energy Technology Data Exchange (ETDEWEB)

Ristov, Milcho [Center of Energy, Informatics and Materials of the Macedonian Academy fo Science and Arts, Skopje (Macedonia, The Former Yugoslav Republic of); Mitrevski, Mitre [Institute of Physics, Faculty of natural Science and Mathematics, Ss Cyril and Methodius University, Skopje (Macedonia, The Former Yugoslav Republic of)

2003-07-01

A very simple Quartz Crystal Microbalance (QCM) was constructed for the measurement of thickness of chemically deposited thin films. QCM consisted of two active elements: one dual-gate MOSFET and one bipolar transistor, and as usually two AT-cut quartz crystal. The beat frequency oscillation generated as a result of loading of the sensor crystal by the deposited thin film, was measured by HP-multimeter, set as a low frequency meter. The sensitivity was found to be high and satisfactory for the study of growth rate of thin films, mainly deposited by methods of chemical deposition.

Construction of simple quartz crystal microbalance

International Nuclear Information System (INIS)

Ristov, Milcho; Mitrevski, Mitre

2002-01-01

A very simple Quartz Crystal Microbalance (QCM) was constructed for the measurement of thickness of chemically deposited thin films. QCM consisted of two active elements: one dual-gate MOSFET and one bipolar transistor, and as usually two AT-cut quartz crystal. The beat frequency oscillation generated as a result of loading of the sensor crystal by the deposited thin film, was measured by HP-multimeter, set as a low frequency meter. The sensitivity was found to be high and satisfactory for the study of growth rate of thin films, mainly deposited by methods of chemical deposition.

Simple methods of aligning four-circle diffractometers with crystal reflections

Energy Technology Data Exchange (ETDEWEB)

Mitsui, Y [Tokyo Univ. (Japan). Faculty of Pharmaceutical Sciences

1979-08-01

Simple methods of aligning four-circle diffractometers with crystal reflections are devised. They provide the methods to check (1) perpendicularity of chi plane to the incident beam, (2) zero point of 2theta and linearity of focus-chi center-receiving aperture and (3) zero point of chi.

Simple PVT quantitative method of Kr under high pure N2 condition

International Nuclear Information System (INIS)

Li Xuesong; Zhang Zibin; Wei Guanyi; Chen Liyun; Zhai Lihua

2005-01-01

A simple PVT quantitative method of Kr in the high pure N 2 was studied. Pressure, volume and temperature of the sample gas were measured by three individual methods to obtain the sum sample with food uncertainty. The ratio of Kr/N 2 could measured by GAM 400 quadrupole mass spectrometer. So the quantity of Kr could be calculated with the two measured data above. This method can be suited for quantitative analysis of other simple composed noble gas sample with high pure carrying gas. (authors)

Novel fabrication of flexible graphene-based chemical sensors with heaters using soft lithographic patterning method.

Science.gov (United States)

Jung, Min Wook; Myung, Sung; Song, Wooseok; Kang, Min-A; Kim, Sung Ho; Yang, Cheol-Soo; Lee, Sun Sook; Lim, Jongsun; Park, Chong-Yun; Lee, Jeong-O; An, Ki-Seok

2014-08-27

We have fabricated graphene-based chemical sensors with flexible heaters for the highly sensitive detection of specific gases. We believe that increasing the temperature of the graphene surface significantly enhanced the electrical signal change of the graphene-based channel, and reduced the recovery time needed to obtain a normal state of equilibrium. In addition, a simple and efficient soft lithographic patterning process was developed via surface energy modification for advanced, graphene-based flexible devices, such as gas sensors. As a proof of concept, we demonstrated the high sensitivity of NO2 gas sensors based on graphene nanosheets. These devices were fabricated using a simple soft-lithographic patterning method, where flexible graphene heaters adjacent to the channel of sensing graphene were utilized to control graphene temperature.

Chemical control methods and tools

Science.gov (United States)

Steven Manning; James. Miller

2011-01-01

After determining the best course of action for control of an invasive plant population, it is important to understand the variety of methods available to the integrated pest management professional. A variety of methods are now widely used in managing invasive plants in natural areas, including chemical, mechanical, and cultural control methods. Once the preferred...

A simple method for generating exactly solvable quantum mechanical potentials

CERN Document Server

Williams, B W

1993-01-01

A simple transformation method permitting the generation of exactly solvable quantum mechanical potentials from special functions solving second-order differential equations is reviewed. This method is applied to Gegenbauer polynomials to generate an attractive radial potential. The relationship of this method to the determination of supersymmetric quantum mechanical superpotentials is discussed, and the superpotential for the radial potential is also derived. (author)

Device for collecting chemical compounds and related methods

Science.gov (United States)

Scott, Jill R.; Groenewold, Gary S.; Rae, Catherine

2013-01-01

A device for sampling chemical compounds from fixed surfaces and related methods are disclosed. The device may include a vacuum source, a chamber and a sorbent material. The device may utilize vacuum extraction to volatilize the chemical compounds from the fixed surfaces so that they may be sorbed by the sorbent material. The sorbent material may then be analyzed using conventional thermal desorption/gas chromatography/mass spectrometry (TD/GC/MS) instrumentation to determine presence of the chemical compounds. The methods may include detecting release and presence of one or more chemical compounds and determining the efficacy of decontamination. The device may be useful in collection and analysis of a variety of chemical compounds, such as residual chemical warfare agents, chemical attribution signatures and toxic industrial chemicals.

Development of Fabrication Methods of Filler/Polymer Nanocomposites: With Focus on Simple Melt-Compounding-Based Approach without Surface Modification of Nanofillers

Science.gov (United States)

Tanahashi, Mitsuru

2010-01-01

Many attempts have been made to fabricate various types of inorganic nanoparticle-filled polymers (filler/polymer nanocomposites) by a mechanical or chemical approach. However, these approaches require modification of the nanofiller surfaces and/or complicated polymerization reactions, making them unsuitable for industrial-scale production of the nanocomposites. The author and coworkers have proposed a simple melt-compounding method for the fabrication of silica/polymer nanocomposites, wherein silica nanoparticles without surface modification were dispersed through the breakdown of loose agglomerates of colloidal nano-silica spheres in a kneaded polymer melt. This review aims to discuss experimental techniques of the proposed method and its advantages over other developed methods.

Development of Fabrication Methods of Filler/Polymer Nanocomposites: With Focus on Simple Melt-Compounding-Based Approach without Surface Modification of Nanofillers

Directory of Open Access Journals (Sweden)

Mitsuru Tanahashi

2010-03-01

Full Text Available Many attempts have been made to fabricate various types of inorganic nanoparticle-filled polymers (filler/polymer nanocomposites by a mechanical or chemical approach. However, these approaches require modification of the nanofiller surfaces and/or complicated polymerization reactions, making them unsuitable for industrial-scale production of the nanocomposites. The author and coworkers have proposed a simple melt-compounding method for the fabrication of silica/polymer nanocomposites, wherein silica nanoparticles without surface modification were dispersed through the breakdown of loose agglomerates of colloidal nano-silica spheres in a kneaded polymer melt. This review aims to discuss experimental techniques of the proposed method and its advantages over other developed methods.

Simple statistical methods for software engineering data and patterns

CERN Document Server

Pandian, C Ravindranath

2015-01-01

Although there are countless books on statistics, few are dedicated to the application of statistical methods to software engineering. Simple Statistical Methods for Software Engineering: Data and Patterns fills that void. Instead of delving into overly complex statistics, the book details simpler solutions that are just as effective and connect with the intuition of problem solvers.Sharing valuable insights into software engineering problems and solutions, the book not only explains the required statistical methods, but also provides many examples, review questions, and case studies that prov

Theoretical considerations and a simple method for measuring alkalinity and acidity in low-pH waters by gran titration

Science.gov (United States)

Barringer, J.L.; Johnsson, P.A.

1996-01-01

Titrations for alkalinity and acidity using the technique described by Gran (1952, Determination of the equivalence point in potentiometric titrations, Part II: The Analyst, v. 77, p. 661-671) have been employed in the analysis of low-pH natural waters. This report includes a synopsis of the theory and calculations associated with Gran's technique and presents a simple and inexpensive method for performing alkalinity and acidity determinations. However, potential sources of error introduced by the chemical character of some waters may limit the utility of Gran's technique. Therefore, the cost- and time-efficient method for performing alkalinity and acidity determinations described in this report is useful for exploring the suitability of Gran's technique in studies of water chemistry.

The modified simple equation method for solving some fractional ...

Indian Academy of Sciences (India)

... and processes in various areas of natural science. Thus, many effective and powerful methods have been established and improved. In this study, we establish exact solutions of the time fractional biological population model equation and nonlinearfractional Klein–Gordon equation by using the modified simple equation ...

A simple method of dosimetry for E-beam radiation

International Nuclear Information System (INIS)

Spencer, D.S.; Thalacker, V.P.; Chasman, J.N.; Siegel, S.

1985-01-01

A simple method utilizing a photochromic 'intensity label' for monitoring electron-beam sources was evaluated. The labels exhibit a color change upon exposure to UV or e-beam radiation. A correlation was found between absorbed energy and Gardner Color Index at low electron-beam doses. (author)

Teaching Beginning Chemistry Students Simple Lewis Dot Structures

Science.gov (United States)

Nassiff, Peter; Czerwinski, Wendy A.

2015-01-01

Students beginning their initial study of chemistry often have a difficult time mastering simple Lewis dot structures. Textbooks show students how to manipulate Lewis structures by moving valence electron dots around the chemical structure so each atom has an octet or duet. However, an easier method of teaching Lewis structures for simple…

Optimized theory for simple and molecular fluids.

Science.gov (United States)

Marucho, M; Montgomery Pettitt, B

2007-03-28

An optimized closure approximation for both simple and molecular fluids is presented. A smooth interpolation between Perkus-Yevick and hypernetted chain closures is optimized by minimizing the free energy self-consistently with respect to the interpolation parameter(s). The molecular version is derived from a refinement of the method for simple fluids. In doing so, a method is proposed which appropriately couples an optimized closure with the variant of the diagrammatically proper integral equation recently introduced by this laboratory [K. M. Dyer et al., J. Chem. Phys. 123, 204512 (2005)]. The simplicity of the expressions involved in this proposed theory has allowed the authors to obtain an analytic expression for the approximate excess chemical potential. This is shown to be an efficient tool to estimate, from first principles, the numerical value of the interpolation parameters defining the aforementioned closure. As a preliminary test, representative models for simple fluids and homonuclear diatomic Lennard-Jones fluids were analyzed, obtaining site-site correlation functions in excellent agreement with simulation data.

Simple and convenient method for culturing anaerobic bacteria.

OpenAIRE

Behbehani, M J; Jordan, H V; Santoro, D L

1982-01-01

A simple and convenient method for culturing anaerobic bacteria is described. Cultures can be grown in commercially available flasks normally used for preparation of sterile external solutions. A special disposable rubber flask closure maintains anaerobic conditions in the flask after autoclaving. Growth of a variety of anaerobic oral bacteria was comparable to that obtained after anaerobic incubation of broth cultures in Brewer Anaerobic Jars.

A simple method for one-loop renormalization in curved space-time

Energy Technology Data Exchange (ETDEWEB)

Markkanen, Tommi [Helsinki Institute of Physics and Department of Physics, P.O. Box 64, FI-00014, University of Helsinki (Finland); Tranberg, Anders, E-mail: tommi.markkanen@helsinki.fi, E-mail: anders.tranberg@uis.no [Niels Bohr International Academy and Discovery Center, Niels Bohr Institute, Blegdamsvej 17, 2100 Copenhagen (Denmark)

2013-08-01

We present a simple method for deriving the renormalization counterterms from the components of the energy-momentum tensor in curved space-time. This method allows control over the finite parts of the counterterms and provides explicit expressions for each term separately. As an example, the method is used for the self-interacting scalar field in a Friedmann-Robertson-Walker metric in the adiabatic approximation, where we calculate the renormalized equation of motion for the field and the renormalized components of the energy-momentum tensor to fourth adiabatic order while including interactions to one-loop order. Within this formalism the trace anomaly, including contributions from interactions, is shown to have a simple derivation. We compare our results to those obtained by two standard methods, finding agreement with the Schwinger-DeWitt expansion but disagreement with adiabatic subtractions for interacting theories.

SimpleTreat 3.0: a model to predict the distribution and elimination of Chemicals by Sewage Treatment Plants

NARCIS (Netherlands)

Struijs J; ECO

1996-01-01

The spreadsheet SimpelTreat 3.0 is a model to predict the distribution and elimination of chemicals by sewage treatment. Simpeltreat 3.0 is an improved version of SimpleTreat, applied in the Netherlands in the Uniform System for the Evaluation of Substances (USES version 1.0, 1994). Although in the

Chemical Risk Assessment Screening Tool of a Global Chemical Company

OpenAIRE

Evelyn Tjoe-Nij; Christophe Rochin; Nathalie Berne; Alessandro Sassi; Antoine Leplay

2018-01-01

Background: This paper describes a simple-to-use and reliable screening tool called Critical Task Exposure Screening (CTES), developed by a chemical company. The tool assesses if the exposure to a chemical for a task is likely to be within acceptable levels. Methods: CTES is a Microsoft Excel tool, where the inhalation risk score is calculated by relating the exposure estimate to the corresponding occupational exposure limit (OEL) or occupational exposure band (OEB). The inhalation exposure i...

A method for assessing residual NAPL based on organic chemical concentrations in soil samples

International Nuclear Information System (INIS)

Feenstra, S.; Mackay, D.M.; Cherry, J.A.

1991-01-01

Ground water contamination by non-aqueous phase liquid (NAPL) chemicals is a serious concern at many industrial facilities and waste disposal sites. NAPL in the form of immobile residual contamination, or pools of mobile or potentially mobile NAPL, can represent continuing sources of ground water contamination. In order to develop rational and cost-effective plans for remediation of soil and ground water contamination at such sites, it is essential to determine if non-aqueous phase liquid (NAPL) chemicals are present in the subsurface and delineate the zones of NAPL contamination. Qualitatively, soil analyses that exhibit chemical concentrations in the percent range or >10,000 mg/kg would generally be considered to indicate the presence of NAPL. However, the results of soil analyses are seldom used in a quantitative manner to assess the possible presence of residual NAPL contamination when chemical concentrations are lower and the presence of NAPL is not obvious. The assessment of the presence of NAPL in soil samples is possible using the results of chemical and physical analyses of the soil, and the fundamental principles of chemical partitioning in unsaturated or saturated soil. The method requires information on the soil of the type typically considered in ground water contamination studies and provides a simple tool for the investigators of chemical spill and waste disposal sites to assess whether soil chemical analyses indicate the presence of residual NAPL in the subsurface

Lowest-order constrained variational method for simple many-fermion systems

International Nuclear Information System (INIS)

Alexandrov, I.; Moszkowski, S.A.; Wong, C.W.

1975-01-01

The authors study the potential energy of many-fermion systems calculated by the lowest-order constrained variational (LOCV) method of Pandharipande. Two simple two-body interactions are used. For a simple hard-core potential in a dilute Fermi gas, they find that the Huang-Yang exclusion correction can be used to determine a healing distance. The result is close to the older Pandharipande prescription for the healing distance. For a hard core plus attractive exponential potential, the LOCV result agrees closely with the lowest-order separation method of Moszkowski and Scott. They find that the LOCV result has a shallow minimum as a function of the healing distance at the Moszkowski-Scott separation distance. The significance of the absence of a Brueckner dispersion correction in the LOCV result is discussed. (Auth.)

A simple method for validation and verification of pipettes mounted on automated liquid handlers

DEFF Research Database (Denmark)

Stangegaard, Michael; Hansen, Anders Johannes; Frøslev, Tobias Guldberg

 We have implemented a simple method for validation and verification of the performance of pipettes mounted on automated liquid handlers as necessary for laboratories accredited under ISO 17025. An 8-step serial dilution of Orange G was prepared in quadruplicates in a flat bottom 96-well microtit...... available. In conclusion, we have set up a simple solution for the continuous validation of automated liquid handlers used for accredited work. The method is cheap, simple and easy to use for aqueous solutions but requires a spectrophotometer that can read microtiter plates....... We have implemented a simple method for validation and verification of the performance of pipettes mounted on automated liquid handlers as necessary for laboratories accredited under ISO 17025. An 8-step serial dilution of Orange G was prepared in quadruplicates in a flat bottom 96-well microtiter...

Investigation of Evaluation method of chemical runaway reaction

International Nuclear Information System (INIS)

Sato, Yoshihiko; Sasaya, Shinji; Kurakata, Koichiro; Nojiri, Ichiro

2002-02-01

Safety study 'Study of evaluation of abnormal occurrence for chemical substances in the nuclear fuel facilities' will be carried out from 2001 to 2005. In this study, the prediction of thermal hazards of chemical substances will be investigated and prepared. The hazard prediction method of chemical substances will be constructed from these results. Therefore, the hazard prediction methods applied in the chemical engineering in which the chemical substances with the hazard of fire and explosion were often treated were investigated. CHETAH (The ASTM Computer Program for Chemical Thermodynamic and Energy Release Evaluation) developed by ASTM (American Society for Testing and Materials) and TSS (Thermal Safety Software) developed by CISP (ChemInform St. Petersburg) were introduced and the fire and explosion hazards of chemical substances and reactions in the reprocessing process were evaluated. From these evaluated results, CHETAH could almost estimate the heat of reaction at 10% accuracy. It was supposed that CHETAH was useful as a screening for the hazards of fire and explosion of the new chemical substances and so on. TSS could calculate the reaction rate and the reaction behavior from the data measured by the various calorimeters rapidly. It was supposed that TSS was useful as an evaluation method for the hazards of fire and explosion of the new chemical reactions and so on. (author)

A simple immunoblotting method after separation of proteins in agarose gel

DEFF Research Database (Denmark)

Koch, C; Skjødt, K; Laursen, I

1985-01-01

A simple and sensitive method for immunoblotting of proteins after separation in agarose gels is described. It involves transfer of proteins onto nitrocellulose paper simply by diffusion through pressure, a transfer which only takes about 10 min. By this method we have demonstrated the existence ...

A simple and rapid infrared-assisted self enzymolysis extraction method for total flavonoid aglycones extraction from Scutellariae Radix and mechanism exploration.

Science.gov (United States)

Wang, Liping; Duan, Haotian; Jiang, Jiebing; Long, Jiakun; Yu, Yingjia; Chen, Guiliang; Duan, Gengli

2017-09-01

A new, simple, and fast infrared-assisted self enzymolysis extraction (IRASEE) approach for the extraction of total flavonoid aglycones (TFA) mainly including baicalein, wogonin, and oroxylin A from Scutellariae Radix is presented to enhance extraction yield. Extraction enzymolysis temperature, enzymolysis liquid-to-solid ratio, enzymolysis pH, enzymolysis time and infrared power, the factors affecting IRASEE procedure, were investigated in a newly designed, temperature-controlled infrared-assisted extraction (TC-IRAE) system to acquire the optimum analysis conditions. The results illustrated that IRASEE possessed great advantages in terms of efficiency and time compared with other conventional extraction techniques. Furthermore, the mechanism of IRASEE was preliminarily explored by observing the microscopic change of the samples surface structures, studying the main chemical compositions change of the samples before and after extraction and investigating the kinetics and thermodynamics at three temperature levels during the IRASEE process. These findings revealed that IRASEE can destroy the surface microstructures to accelerate the mass transfer and reduce the activation energy to intensify the chemical process. This integrative study presents a simple, rapid, efficient, and environmental IRASEE method for TFA extraction which has promising prospects for other similar herbal medicines. Graphical Abstract ᅟ.

A simple method of fitting ill-conditioned polynomials to data

International Nuclear Information System (INIS)

Buckler, A.N.; Lawrence, J.

1979-04-01

A very simple transformation of the independent variable x is shown to cure the ill-conditioning when some polynomial series are fitted to given Y values. Numerical examples are given to illustrate the power of the method. (author)

SU-8 Cantilevers for Bio/chemical Sensing; Fabrication, Characterisation and Development of Novel Read-out Methods

OpenAIRE

Anja Boisen; Mogens Havsteen-Jakobsen; Gabriela Blagoi; Daniel Haefliger; Søren Dohn; Alicia Johansson; Michael Lillemose; Stephan Keller; Maria Nordström

2008-01-01

Here, we present the activities within our research group over the last five years with cantilevers fabricated in the polymer SU-8. We believe that SU-8 is an interesting polymer for fabrication of cantilevers for bio/chemical sensing due to its simple processing and low Young's modulus. We show examples of different integrated read-out methods and their characterisation. We also show that SU-8 cantilevers have a reduced sensitivity to changes in the environmental temperature and pH of the bu...

Chemical Methods to Knock Down the Amyloid Proteins

Directory of Open Access Journals (Sweden)

Na Gao

2017-06-01

Full Text Available Amyloid proteins are closely related with amyloid diseases and do tremendous harm to human health. However, there is still a lack of effective strategies to treat these amyloid diseases, so it is important to develop novel methods. Accelerating the clearance of amyloid proteins is a favorable method for amyloid disease treatment. Recently, chemical methods for protein reduction have been developed and have attracted much attention. In this review, we focus on the latest progress of chemical methods that knock down amyloid proteins, including the proteolysis-targeting chimera (PROTAC strategy, the “recognition-cleavage” strategy, the chaperone-mediated autophagy (CMA strategy, the selectively light-activatable organic and inorganic molecules strategy and other chemical strategies.

The simple modelling method for storm- and grey-water quality ...

African Journals Online (AJOL)

The simple modelling method for storm- and grey-water quality management applied to Alexandra settlement. ... objectives optimally consist of educational programmes, erosion and sediment control, street sweeping, removal of sanitation system overflows, impervious cover reduction, downspout disconnections, removal of ...

A Simple Method for Identifying the Acromioclavicular Joint During Arthroscopic Procedures

OpenAIRE

Javed, Saqib; Heasley, Richard; Ravenscroft, Matt

2013-01-01

Arthroscopic acromioclavicular joint excision is performed via an anterior portal and is technically demanding. We present a simple method for identifying the acromioclavicular joint during arthroscopic procedures.

A simple method for estimating thermal response of building ...

African Journals Online (AJOL)

This paper develops a simple method for estimating the thermal response of building materials in the tropical climatic zone using the basic heat equation. The efficacy of the developed model has been tested with data from three West African cities, namely Kano (lat. 12.1 ºN) Nigeria, Ibadan (lat. 7.4 ºN) Nigeria and Cotonou ...

Surface modification of porous poly(tetrafluoraethylene) film by a simple chemical oxidation treatment

International Nuclear Information System (INIS)

Wang Shifang; Li Juan; Suo Jinping; Luo Tianzhi

2010-01-01

A simple, inexpensive and environmental chemical treatment process, i.e., treating porous poly(tetrafluoroethylene) (PTFE) films by a mixture of potassium permanganate solution and nitric acid, was proposed to improve the hydrophilicity of PTFE. To evaluate the effectiveness of this strong oxidation treatment, contact angle measurement was performed. The effects of treatment time and temperature on the contact angle of PTFE were studied as well. The results showed that the chemical modification decreased contact angle of as-received PTFE film from 133 ± 3 deg. to 30 ± 4 deg. treated at 100 deg. C for 3 h, effectively converting the hydrophobic PTFE to a hydrophilic PTFE matrix. The changes in chemical structure, surface compositions and crystal structure of PTFE were examined by attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), environmental scanning electron microscopy (ESEM), X-ray diffraction (XRD), respectively. It was found that the F/C atomic ratio decreased from untreated 1.65-0.10 treated by the mixture at 100 deg. C for 3 h. Hydrophilic groups such as carbonyl (C=O) and hydroxyl (-OH) were introduced on the surface of PTFE after treatment. Furthermore, hydrophilic compounds K 0.27 MnO 2 .0.54H 2 O was absorbed on the surface of porous PTFE film. Both the introduction of hydrophilic groups and absorption of hydrophilic compounds contribute to the significantly decreased contact angle of PTFE.

Surface modification of porous poly(tetrafluoraethylene) film by a simple chemical oxidation treatment

Energy Technology Data Exchange (ETDEWEB)

Wang Shifang; Li Juan [State Key Laboratory of Mould Technology, Department of Materials Science and Engineering, Huazhong University of Science and Technology, Luo-Yu Road 1037, Wuhan, Hubei 430074 (China); Suo Jinping, E-mail: jpsuo@yahoo.com.cn [State Key Laboratory of Mould Technology, Department of Materials Science and Engineering, Huazhong University of Science and Technology, Luo-Yu Road 1037, Wuhan, Hubei 430074 (China); Luo Tianzhi [State Key Laboratory of Mould Technology, Department of Materials Science and Engineering, Huazhong University of Science and Technology, Luo-Yu Road 1037, Wuhan, Hubei 430074 (China)

2010-01-15

A simple, inexpensive and environmental chemical treatment process, i.e., treating porous poly(tetrafluoroethylene) (PTFE) films by a mixture of potassium permanganate solution and nitric acid, was proposed to improve the hydrophilicity of PTFE. To evaluate the effectiveness of this strong oxidation treatment, contact angle measurement was performed. The effects of treatment time and temperature on the contact angle of PTFE were studied as well. The results showed that the chemical modification decreased contact angle of as-received PTFE film from 133 {+-} 3 deg. to 30 {+-} 4 deg. treated at 100 deg. C for 3 h, effectively converting the hydrophobic PTFE to a hydrophilic PTFE matrix. The changes in chemical structure, surface compositions and crystal structure of PTFE were examined by attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), environmental scanning electron microscopy (ESEM), X-ray diffraction (XRD), respectively. It was found that the F/C atomic ratio decreased from untreated 1.65-0.10 treated by the mixture at 100 deg. C for 3 h. Hydrophilic groups such as carbonyl (C=O) and hydroxyl (-OH) were introduced on the surface of PTFE after treatment. Furthermore, hydrophilic compounds K{sub 0.27}MnO{sub 2}.0.54H{sub 2}O was absorbed on the surface of porous PTFE film. Both the introduction of hydrophilic groups and absorption of hydrophilic compounds contribute to the significantly decreased contact angle of PTFE.

Survey of Nuclear Methods in Chemical Technology

International Nuclear Information System (INIS)

Broda, E.

1966-01-01

An attempt is made to classify nuclear methods on a logical basis to facilitate assimilation by the technologist. The three main groups are: (I) Tracer methods, (II) Methods based on the influence of absorbers on radiations to be measured, and (III) Radiation chemical methods. The variants of the first two groups are discussed in some detail, and typical examples are given. Group I can be subdivided into (1) Indicator methods, (2) Emanation methods, (3) Radioreagent methods, and (4) Isotope dilution methods, Group II into (5) Activation methods, (6) Absorption methods, (7) Induced Nuclear Reaction methods, (8) Scattering methods, and (9) Fluorescence methods. While the economic benefits due to nuclear methods already run into hundreds of millions of dollars annually, owing to radiation protection problems radiochemical methods in the strict sense are not widely used in actual production. It is suggested that more use should be made of pilot plant tracer studies of chemical processes as used in industry. (author)

A simple and rapid method to graft hydroxyapatite on carbon nanotubes

International Nuclear Information System (INIS)

Neelgund, Gururaj M.; Olurode, Kehinde; Luo Zhiping; Oki, Aderemi

2011-01-01

Herein a simple and effective approach is introduced to functionalize single walled carbon nanotubes (SWCNTs) by in-situ grafting of hydroxyapatite (HA). The pristine SWCNTs were chemically activated through introduction of carboxylic groups on their surfaces by refluxing in the mixture of H 2 SO 4 and HNO 3 . The resulting carboxylated SWCNTs were further utilized for grafting of HA. The Fourier transform infrared and Raman spectroscopic studies demonstrated the formation of HA and its grafting over SWCNTs. The phase composition of HA and existence Ca 2+ and PO 4 3- ions were studied using X-ray diffraction and energy dispersive X-ray analyses, respectively. The surface morphology of functionalized SWCNTs was analyzed using scanning electron microscopy and transmission electron microscopy. Thermogravimetric analysis confirmed the existence of HA on SWCNTs by exhibiting different thermogram for pure HA and functionalized SWCNTs. Overall, this method produced uniform grafting of low crystalline HA on carboxylated SWCNTs with strong interfacial bonding. - Graphical abstract: A facile approach is demonstrated for effective functionalization of single walled carbon nanotubes (SWCNTs) by in-situ grafting of hydroxyapatite (HA) to improve hydrophilicity and biocompatibility of SWCNTs. This method produced uniform grafting of low crystalline HA on carboxylated SWCNTs with strong interfacial bonding. Research highlights: → This method is facile and effective to graft HA on SWCNTs. → As f-SWCNTs is a promising biomaterial to use without any further processing → This technique is economic, easy to repeat and can be optimized for mass production. → Ratio of Ca to P in f-SWCNTs was 1.65, which is near to ratio present in bone tissue.

A simple and rapid method to graft hydroxyapatite on carbon nanotubes

Energy Technology Data Exchange (ETDEWEB)

Neelgund, Gururaj M.; Olurode, Kehinde [Department of Chemistry, Prairie View A and M University, Prairie View, TX 77446 (United States); Luo Zhiping [Microscopy and Imaging Center, Materials Science and Engineering, Texas A and M University, College Station TX 77843 (United States); Oki, Aderemi, E-mail: aroki@pvamu.edu [Department of Chemistry, Prairie View A and M University, Prairie View, TX 77446 (United States)

2011-10-10

Herein a simple and effective approach is introduced to functionalize single walled carbon nanotubes (SWCNTs) by in-situ grafting of hydroxyapatite (HA). The pristine SWCNTs were chemically activated through introduction of carboxylic groups on their surfaces by refluxing in the mixture of H{sub 2}SO{sub 4} and HNO{sub 3}. The resulting carboxylated SWCNTs were further utilized for grafting of HA. The Fourier transform infrared and Raman spectroscopic studies demonstrated the formation of HA and its grafting over SWCNTs. The phase composition of HA and existence Ca{sup 2+} and PO{sub 4}{sup 3-} ions were studied using X-ray diffraction and energy dispersive X-ray analyses, respectively. The surface morphology of functionalized SWCNTs was analyzed using scanning electron microscopy and transmission electron microscopy. Thermogravimetric analysis confirmed the existence of HA on SWCNTs by exhibiting different thermogram for pure HA and functionalized SWCNTs. Overall, this method produced uniform grafting of low crystalline HA on carboxylated SWCNTs with strong interfacial bonding. - Graphical abstract: A facile approach is demonstrated for effective functionalization of single walled carbon nanotubes (SWCNTs) by in-situ grafting of hydroxyapatite (HA) to improve hydrophilicity and biocompatibility of SWCNTs. This method produced uniform grafting of low crystalline HA on carboxylated SWCNTs with strong interfacial bonding. Research highlights: {yields} This method is facile and effective to graft HA on SWCNTs. {yields} As f-SWCNTs is a promising biomaterial to use without any further processing {yields} This technique is economic, easy to repeat and can be optimized for mass production. {yields} Ratio of Ca to P in f-SWCNTs was 1.65, which is near to ratio present in bone tissue.

Fill rate estimation in periodic review policies with lost sales using simple methods

Energy Technology Data Exchange (ETDEWEB)

Cardós, M.; Guijarro Tarradellas, E.; Babiloni Griñón, E.

2016-07-01

Purpose: The exact estimation of the fill rate in the lost sales case is complex and time consuming. However, simple and suitable methods are needed for its estimation so that inventory managers could use them. Design/methodology/approach: Instead of trying to compute the fill rate in one step, this paper focuses first on estimating the probabilities of different on-hand stock levels so that the fill rate is computed later. Findings: As a result, the performance of a novel proposed method overcomes the other methods and is relatively simple to compute. Originality/value: Existing methods for estimating stock levels are examined, new procedures are proposed and their performance is assessed.

Computer simulation of chemical nucleation

International Nuclear Information System (INIS)

Turner, J.S.

1979-01-01

The problem of nucleation at chemical instabilities is investigated by means of microscopic computer simulation. The first-order transition of interest involves a new kind of nucleation arising from chemical transformations rather than physical forces. Here it is the chemical state of matter, and not matter itself, which is spatially localized to form the nucleus for transition between different chemical states. First, the concepts of chemical instability, nonequilibrium phase transition, and dissipative structure are reviewed briefly. Then recently developed methods of reactive molecular dynamics are used to study chemical nucleation in a simple model chemical reactions. Finally, the connection of these studies to nucleation and condensation processes involving physical and chemical interactions is explored. (orig.)

A Simple DTC-SVM method for Matrix Converter Drives Using a Deadbeat Scheme

DEFF Research Database (Denmark)

Lee, Kyo-Beum; Blaabjerg, Frede; Lee, Kwang-Won

2005-01-01

In this paper, a simple direct torque control (DTC) method for sensorless matrix converter drives is proposed, which is characterized by a simple structure, minimal torque ripple and unity input power factor. Also a good sensorless speed-control performance in the low speed operation is obtained,...

12 CFR 334.25 - Reasonable and simple methods of opting out.

Science.gov (United States)

2010-01-01

... STATEMENTS OF GENERAL POLICY FAIR CREDIT REPORTING Affiliate Marketing § 334.25 Reasonable and simple methods... or processed at an Internet Web site, if the consumer agrees to the electronic delivery of... opt-out under the Act, and the affiliate marketing opt-out under the Act, by a single method, such as...

Safety in the Chemical Laboratory: Tested Disposal Methods for Chemical Wastes from Academic Laboratories.

Science.gov (United States)

Armour, M. A.; And Others

1985-01-01

Describes procedures for disposing of dichromate cleaning solution, picric acid, organic azides, oxalic acid, chemical spills, and hydroperoxides in ethers and alkenes. These methods have been tested under laboratory conditions and are specific for individual chemicals rather than for groups of chemicals. (JN)

The Box-and-Dot Method: A Simple Strategy for Counting Significant Figures

Science.gov (United States)

Stephenson, W. Kirk

2009-01-01

A visual method for counting significant digits is presented. This easy-to-learn (and easy-to-teach) method, designated the box-and-dot method, uses the device of "boxing" significant figures based on two simple rules, then counting the number of digits in the boxes. (Contains 4 notes.)

Chemical decontaminating method for stainless steel

International Nuclear Information System (INIS)

Onuma, Tsutomu; Akimoto, Hidetoshi.

1990-01-01

Radioactive metal wastes comprising passivated stainless steels are chemically decontaminated to such a radioactivity level as that of usual wastes. The present invention for chemically decontaminating stainless steels comprises a first step of immersing decontaminates into a sulfuric acid solution and a second step of immersing them into an aqueous solution prepared by adding oxidative metal salts to sulfuric acid, in which a portion of the surface of stainless steels as decontaminates are chemically ground to partially expose substrate materials and then the above-mentioned decontamination steps are applied. More than 90% of radioactive materials are removed in this method by the dissolution of the exposed substrate materials and peeling of cruds secured to the surface of the materials upon dissolution. This method is applicable to decontamination of articles having complicate shapes, can reduce the amount of secondary wastes after decontamination and also remarkably shorten the time required for decontamination. (T.M.)

Approximate method of calculation of non-equilibrium flow parameters of chemically reacting nitrogen tetroxide in the variable cross-section channels with energy exchange

International Nuclear Information System (INIS)

Bazhin, M.A.; Fedosenko, G.Eh.; Shiryaeva, N.M.; Mal'ko, M.V.

1986-01-01

It is shown that adiabatic non-equilibrium chemically reacting gas flow with energy exchange in a variable cross-section channel may be subdivided into five possible types: 1) quasi-equilibrium flow; 2) flow in the linear region of deviation from equilibrium state; 3) quasi-frozen flow; 4) flow in the linear region of deviation from frozen state; 5) non-equilibrium flow. Criteria of quasi-equilibrium and quazi-frozen flows, including factors of external action of chemically reacting gas on flow, allow to obtain simple but sufficiently reliable approximate method of calculation of flow parameters. The considered method for solving the problem of chemically reacting nitrogen tetroxide in the variable cross-section channel with energy exchange can be used for evaluation of chemical reaction kinetics on the flow parameter in the stages of axial-flow and radial-flow turbines and in another practical problems

A Simple and Automatic Method for Locating Surgical Guide Hole

Science.gov (United States)

Li, Xun; Chen, Ming; Tang, Kai

2017-12-01

Restoration-driven surgical guides are widely used in implant surgery. This study aims to provide a simple and valid method of automatically locating surgical guide hole, which can reduce operator's experiences and improve the design efficiency and quality of surgical guide. Few literatures can be found on this topic and the paper proposed a novel and simple method to solve this problem. In this paper, a local coordinate system for each objective tooth is geometrically constructed in CAD system. This coordinate system well represents dental anatomical features and the center axis of the objective tooth (coincide with the corresponding guide hole axis) can be quickly evaluated in this coordinate system, finishing the location of the guide hole. The proposed method has been verified by comparing two types of benchmarks: manual operation by one skilled doctor with over 15-year experiences (used in most hospitals) and automatic way using one popular commercial package Simplant (used in few hospitals).Both the benchmarks and the proposed method are analyzed in their stress distribution when chewing and biting. The stress distribution is visually shown and plotted as a graph. The results show that the proposed method has much better stress distribution than the manual operation and slightly better than Simplant, which will significantly reduce the risk of cervical margin collapse and extend the wear life of the restoration.

Method of Factor Extraction and Simple Structure of Data from Diverse Scientific Areas.

Science.gov (United States)

Thorndike, Robert M.

To study the applicability of simple structure logic for factorial data from scientific disciplines outside psychology, four correlation matrices from each of six scientific areas were factor analyzed by five factoring methods. Resulting factor matrices were compared on two objective criteria of simple structure before and after rotation.…

Establishment of a Simple and Useful Way for Preimplantation Genetic Diagnosis of Chromosomal Diseases

Institute of Scientific and Technical Information of China (English)

LUO Haining; ZHU Guijin; LIU Qun; CHEN Wen; LI Zhou

2007-01-01

In order to establish a simple and useful way for preimplantation genetic diagnosis (PGD)of chromosomal diseases in general IVF laboratory, the methods that are most commonly used in the embryo biopsy, fixation of blastomere and fluorescence in situ hybridization were compared. The three aspects of PGD were analyzed respectively. There was no significant difference in further development capacity of embryos between mechanical (79.7%) and chemical biopsy group (78.6%)(P＞0.05). In this study, more cells were successfully fixed with the Tween/HCL method (93.8%) than with the methanol/acetic acid method (80.5%, P＜0.05). There was no significant difference in cytoplasm remains between methanol/acetic acid method and Tween/HCL method (P＞0.05). The hybridization efficiency of fluorescence in situ hybridization was 89.5% in successive denaturation method and 90.9% in codenaturation method with the difference being not significant (P＞0.05). In conclusion, the mechanical or chemical method, Tween/HCL fixation method and codenaturation fluorescence in situ hybridization method can constitute a simple and useful way for PGD of chromosomal diseases.

A simple method for tuning the glass transition process in inorganic phosphate glasses

Science.gov (United States)

Fulchiron, René; Belyamani, Imane; Otaigbe, Joshua U.; Bounor-Legaré, Véronique

2015-02-01

The physical modification of glass transition temperature (Tg) and properties of materials via blending is a common practice in industry and academia and has a large economic advantage. In this context, simple production of hitherto unattainable new inorganic glass blends from already existing glass compositions via blending raises much hope with the potential to provide new glasses with new and improved properties, that cannot be achieved with classical glass synthesis, for a plethora of applications such as computers screens, glass-to-metal seals, and storage materials for nuclear wastes. Here, we demonstrate that blends of the specific glass compositions studied are miscible in all proportions, an unreported phenomenon in hard condensed matter like glass. Interestingly, excellent agreement was found between the obtained data and calculated Tgs from theoretical equations (Supplementary information) for predicting the composition dependence of Tg for miscible blends with weak but significant specific interactions between the blend components. That this blending method is at present not applied to inorganic glasses reflects the fact that water and chemically resistant phosphate glasses with relatively low Tgs have become available only recently.

A Simple Microsoft Excel Method to Predict Antibiotic Outbreaks and Underutilization.

Science.gov (United States)

Miglis, Cristina; Rhodes, Nathaniel J; Avedissian, Sean N; Zembower, Teresa R; Postelnick, Michael; Wunderink, Richard G; Sutton, Sarah H; Scheetz, Marc H

2017-07-01

Benchmarking strategies are needed to promote the appropriate use of antibiotics. We have adapted a simple regressive method in Microsoft Excel that is easily implementable and creates predictive indices. This method trends consumption over time and can identify periods of over- and underuse at the hospital level. Infect Control Hosp Epidemiol 2017;38:860-862.

A Simple Refraction Experiment for Probing Diffusion in Ternary Mixtures

Science.gov (United States)

Coutinho, Cecil A.; Mankidy, Bijith D.; Gupta, Vinay K.

2010-01-01

Diffusion is a fundamental phenomenon that is vital in many chemical processes such as mass transport in living cells, corrosion, and separations. We describe a simple undergraduate-level experiment based on Weiner's Method to probe diffusion in a ternary aqueous mixture of small molecular-weight molecules. As an illustration, the experiment…

Soil chemical sensor and precision agricultural chemical delivery system and method

Science.gov (United States)

Colburn, Jr., John W.

1991-01-01

A real time soil chemical sensor and precision agricultural chemical delivery system includes a plurality of ground-engaging tools in association with individual soil sensors which measure soil chemical levels. The system includes the addition of a solvent which rapidly saturates the soil/tool interface to form a conductive solution of chemicals leached from the soil. A multivalent electrode, positioned within a multivalent frame of the ground-engaging tool, applies a voltage or impresses a current between the electrode and the tool frame. A real-time soil chemical sensor and controller senses the electrochemical reaction resulting from the application of the voltage or current to the leachate, measures it by resistivity methods, and compares it against pre-set resistivity levels for substances leached by the solvent. Still greater precision is obtained by calibrating for the secondary current impressed through solvent-less soil. The appropriate concentration is then found and the servo-controlled delivery system applies the appropriate amount of fertilizer or agricultural chemicals substantially in the location from which the soil measurement was taken.

A Simple Method for Dynamic Scheduling in a Heterogeneous Computing System

OpenAIRE

Žumer, Viljem; Brest, Janez

2002-01-01

A simple method for the dynamic scheduling on a heterogeneous computing system is proposed in this paper. It was implemented to minimize the parallel program execution time. The proposed method decomposes the program workload into computationally homogeneous subtasks, which may be of the different size, depending on the current load of each machine in a heterogeneous computing system.

Double-lock technique: a simple method to secure abdominal wall closure

International Nuclear Information System (INIS)

Jategaonkar, P.A.; Yadav, S.P.

2013-01-01

Secure closure of a laparotomy incision remains an important aspect of any abdominal operation with the aim to avoid the postoperative morbidity and hasten the patient's recovery. Depending on the operator's preference and experience, it may be done by the continuous or the interrupted methods either using a non-absorbable or delayed-absorbable suture. We describe a simple, secure and quick technique of abdominal wall closure which involves continuous suture inter-locked doubly after every third bite. This simple and easy to use mass closure technique can be easily mastered by any member of the surgical team and does not need any assistant. It amalgamates the advantages of both, the continuous and the interrupted methods of closures. To our knowledge, such a technique has not been reported in the literature. (author)

Some new, simple and efficient stereological methods and their use in pathological research and diagnosis

DEFF Research Database (Denmark)

Gundersen, H J; Bendtsen, T F; Korbo, L

1988-01-01

Stereology is a set of simple and efficient methods for quantitation of three-dimensional microscopic structures which is specifically tuned to provide reliable data from sections. Within the last few years, a number of new methods has been developed which are of special interest to pathologists...... are invariably simple and easy....

Process control and optimization with simple interval calculation method

DEFF Research Database (Denmark)

Pomerantsev, A.; Rodionova, O.; Høskuldsson, Agnar

2006-01-01

for the quality improvement in the course of production. The latter is an active quality optimization, which takes into account the actual history of the process. The advocate approach is allied to the conventional method of multivariate statistical process control (MSPC) as it also employs the historical process......Methods of process control and optimization are presented and illustrated with a real world example. The optimization methods are based on the PLS block modeling as well as on the simple interval calculation methods of interval prediction and object status classification. It is proposed to employ...... the series of expanding PLS/SIC models in order to support the on-line process improvements. This method helps to predict the effect of planned actions on the product quality and thus enables passive quality control. We have also considered an optimization approach that proposes the correcting actions...

Simple method for quick estimation of aquifer hydrogeological parameters

Science.gov (United States)

Ma, C.; Li, Y. Y.

2017-08-01

Development of simple and accurate methods to determine the aquifer hydrogeological parameters was of importance for groundwater resources assessment and management. Aiming at the present issue of estimating aquifer parameters based on some data of the unsteady pumping test, a fitting function of Theis well function was proposed using fitting optimization method and then a unitary linear regression equation was established. The aquifer parameters could be obtained by solving coefficients of the regression equation. The application of the proposed method was illustrated, using two published data sets. By the error statistics and analysis on the pumping drawdown, it showed that the method proposed in this paper yielded quick and accurate estimates of the aquifer parameters. The proposed method could reliably identify the aquifer parameters from long distance observed drawdowns and early drawdowns. It was hoped that the proposed method in this paper would be helpful for practicing hydrogeologists and hydrologists.

Peristalticity-driven banded chemical garden

Science.gov (United States)

Pópity-Tóth, É.; Schuszter, G.; Horváth, D.; Tóth, Á.

2018-05-01

Complex structures in nature are often formed by self-assembly. In order to mimic the formation, to enhance the production, or to modify the structures, easy-to-use methods are sought to couple engineering and self-assembly. Chemical-garden-like precipitation reactions are frequently used to study such couplings because of the intrinsic chemical and hydrodynamic interplays. In this work, we present a simple method of applying periodic pressure fluctuations given by a peristaltic pump which can be used to achieve regularly banded precipitate membranes in the copper-phosphate system.

A New and Simple Method for Crosstalk Estimation in Homogeneous Trench-Assisted Multi-Core Fibers

DEFF Research Database (Denmark)

Ye, Feihong; Tu, Jiajing; Saitoh, Kunimasa

2014-01-01

A new and simple method for inter-core crosstalk estimation in homogeneous trench-assisted multi-core fibers is presented. The crosstalk calculated by this method agrees well with experimental measurement data for two kinds of fabricated 12-core fibers.......A new and simple method for inter-core crosstalk estimation in homogeneous trench-assisted multi-core fibers is presented. The crosstalk calculated by this method agrees well with experimental measurement data for two kinds of fabricated 12-core fibers....

Simple method to generate and fabricate stochastic porous scaffolds

Energy Technology Data Exchange (ETDEWEB)

Yang, Nan, E-mail: y79nzw@163.com; Gao, Lilan; Zhou, Kuntao

2015-11-01

Considerable effort has been made to generate regular porous structures (RPSs) using function-based methods, although little effort has been made for constructing stochastic porous structures (SPSs) using the same methods. In this short communication, we propose a straightforward method for SPS construction that is simple in terms of methodology and the operations used. Using our method, we can obtain a SPS with functionally graded, heterogeneous and interconnected pores, target pore size and porosity distributions, which are useful for applications in tissue engineering. The resulting SPS models can be directly fabricated using additive manufacturing (AM) techniques. - Highlights: • Random porous structures are constructed based on their regular counterparts. • Functionally graded random pores can be constructed easily. • The scaffolds can be directly fabricated using additive manufacturing techniques.

A simple method to adapt time sampling of the analog signal

International Nuclear Information System (INIS)

Kalinin, Yu.G.; Martyanov, I.S.; Sadykov, Kh.; Zastrozhnova, N.N.

2004-01-01

In this paper we briefly describe the time sampling method, which is adapted to the speed of the signal change. Principally, this method is based on a simple idea--the combination of discrete integration with differentiation of the analog signal. This method can be used in nuclear electronics research into the characteristics of detectors and the shape of the pulse signal, pulse and transitive characteristics of inertial systems of processing of signals, etc

Physical-chemical property based sequence motifs and methods regarding same

Science.gov (United States)

Braun, Werner [Friendswood, TX; Mathura, Venkatarajan S [Sarasota, FL; Schein, Catherine H [Friendswood, TX

2008-09-09

A data analysis system, program, and/or method, e.g., a data mining/data exploration method, using physical-chemical property motifs. For example, a sequence database may be searched for identifying segments thereof having physical-chemical properties similar to the physical-chemical property motifs.

Simple method for correct enumeration of Staphylococcus aureus

DEFF Research Database (Denmark)

Haaber, J.; Cohn, M. T.; Petersen, A.

2016-01-01

culture. When grown in such liquid cultures, the human pathogen Staphylococcus aureus is characterized by its aggregation of single cells into clusters of variable size. Here, we show that aggregation during growth in the laboratory standard medium tryptic soy broth (TSB) is common among clinical...... and laboratory S. aureus isolates and that aggregation may introduce significant bias when applying standard enumeration methods on S. aureus growing in laboratory batch cultures. We provide a simple and efficient sonication procedure, which can be applied prior to optical density measurements to give...

A Rapid and Simple Bioassay Method for Herbicide Detection

Directory of Open Access Journals (Sweden)

Xiu-Qing Li

2008-01-01

Full Text Available Chlamydomonas reinhardtii, a unicellular green alga, has been used in bioassay detection of a variety of toxic compounds such as pesticides and toxic metals, but mainly using liquid culture systems. In this study, an algal lawn--agar system for semi-quantitative bioassay of herbicidal activities has been developed. Sixteen different herbicides belonging to 11 different categories were applied to paper disks and placed on green alga lawns in Petri dishes. Presence of herbicide activities was indicated by clearing zones around the paper disks on the lawn 2-3 days after application. The different groups of herbicides induced clearing zones of variable size that depended on the amount, mode of action, and chemical properties of the herbicides applied to the paper disks. This simple, paper-disk-algal system may be used to detect the presence of herbicides in water samples and act as a quick and inexpensive semi-quantitative screening for assessing herbicide contamination.

Simple Screening Methods for Drought and Heat Tolerance in Cowpea

International Nuclear Information System (INIS)

Singh, B. B.

2000-10-01

Success in breeding for drought tolerance has not been as pronounced as for other traits. This is partly due to lack of simple, cheap and reliable screening methods to select drought tolerant plants/progenies from the segregating populations and partly due to complexity of factors involved in drought tolerance. Measuring drought tolerance through physiological parameters is expensive, time consuming and difficult to use for screening large numbers of lines and segregating populations. Since several factors/mechanisms (in shoot and root) operate independently and/or jointly to enable plants to cope with drought stress, drought tolerance appears as a complex trait. However, if these factors/mechanisms can be separated and studied individually, the components leading to drought tolerance will appear less complex and may be easy to manipulate by breeders. We have developed a simple box screening method for shoot drought tolerance in cowpea, which eliminates the effects of roots and permits non-destructive visual identification of shoot dehydration tolerance. We have also developed a 'root-box pin-board' method to study two dimensional root architecture of individual plants. Using these methods, we have identified two mechanisms of shoot drought tolerance in cowpea which are controlled by single dominant genes and major difference for root architecture among cowpea varieties. Combining deep and dense root system with shoot dehydration tolerance results into highly drought tolerant plants

A simple and efficient method for isolating small RNAs from different plant species

Directory of Open Access Journals (Sweden)

de Folter Stefan

2011-02-01

Full Text Available Abstract Background Small RNAs emerged over the last decade as key regulators in diverse biological processes in eukaryotic organisms. To identify and study small RNAs, good and efficient protocols are necessary to isolate them, which sometimes may be challenging due to the composition of specific tissues of certain plant species. Here we describe a simple and efficient method to isolate small RNAs from different plant species. Results We developed a simple and efficient method to isolate small RNAs from different plant species by first comparing different total RNA extraction protocols, followed by streamlining the best one, finally resulting in a small RNA extraction method that has no need of first total RNA extraction and is not based on the commercially available TRIzol® Reagent or columns. This small RNA extraction method not only works well for plant tissues with high polysaccharide content, like cactus, agave, banana, and tomato, but also for plant species like Arabidopsis or tobacco. Furthermore, the obtained small RNA samples were successfully used in northern blot assays. Conclusion Here we provide a simple and efficient method to isolate small RNAs from different plant species, such as cactus, agave, banana, tomato, Arabidopsis, and tobacco, and the small RNAs from this simplified and low cost method is suitable for downstream handling like northern blot assays.

A simple encapsulation method for organic optoelectronic devices

International Nuclear Information System (INIS)

Sun Qian-Qian; An Qiao-Shi; Zhang Fu-Jun

2014-01-01

The performances of organic optoelectronic devices, such as organic light emitting diodes and polymer solar cells, have rapidly improved in the past decade. The stability of an organic optoelectronic device has become a key problem for further development. In this paper, we report one simple encapsulation method for organic optoelectronic devices with a parafilm, based on ternary polymer solar cells (PSCs). The power conversion efficiencies (PCE) of PSCs with and without encapsulation decrease from 2.93% to 2.17% and from 2.87% to 1.16% after 168-hours of degradation under an ambient environment, respectively. The stability of PSCs could be enhanced by encapsulation with a parafilm. The encapsulation method is a competitive choice for organic optoelectronic devices, owing to its low cost and compatibility with flexible devices. (atomic and molecular physics)

Determination of Urine Albumin by New Simple High-Performance Liquid Chromatography Method.

Science.gov (United States)

Klapkova, Eva; Fortova, Magdalena; Prusa, Richard; Moravcova, Libuse; Kotaska, Karel

2016-11-01

A simple high-performance liquid chromatography (HPLC) method was developed for the determination of albumin in patients' urine samples without coeluting proteins and was compared with the immunoturbidimetric determination of albumin. Urine albumin is important biomarker in diabetic patients, but part of it is immuno-nonreactive. Albumin was determined by high-performance liquid chromatography (HPLC), UV detection at 280 nm, Zorbax 300SB-C3 column. Immunoturbidimetric analysis was performed using commercial kit on automatic biochemistry analyzer COBAS INTEGRA ® 400, Roche Diagnostics GmbH, Manheim, Germany. The HLPC method was fully validated. No significant interference with other proteins (transferrin, α-1-acid glycoprotein, α-1-antichymotrypsin, antitrypsin, hemopexin) was found. The results from 301 urine samples were compared with immunochemical determination. We found a statistically significant difference between these methods (P = 0.0001, Mann-Whitney test). New simple HPLC method was developed for the determination of urine albumin without coeluting proteins. Our data indicate that the HPLC method is highly specific and more sensitive than immunoturbidimetry. © 2016 Wiley Periodicals, Inc.

A simple method suitable to study de novo root organogenesis

Directory of Open Access Journals (Sweden)

Xiaodong eChen

2014-05-01

Full Text Available De novo root organogenesis is the process in which adventitious roots regenerate from detached or wounded plant tissues or organs. In tissue culture, appropriate types and concentrations of plant hormones in the medium are critical for inducing adventitious roots. However, in natural conditions, regeneration from detached organs is likely to rely on endogenous hormones. To investigate the actions of endogenous hormones and the molecular mechanisms guiding de novo root organogenesis, we developed a simple method to imitate natural conditions for adventitious root formation by culturing Arabidopsis thaliana leaf explants on B5 medium without additive hormones. Here we show that the ability of the leaf explants to regenerate roots depends on the age of the leaf and on certain nutrients in the medium. Based on these observations, we provide examples of how this method can be used in different situations, and how it can be optimized. This simple method could be used to investigate the effects of various physiological and molecular changes on the regeneration of adventitious roots. It is also useful for tracing cell lineage during the regeneration process by differential interference contrast observation of -glucuronidase staining, and by live imaging of proteins labeled with fluorescent tags.

High Operating Voltage Supercapacitor Using PPy/AC Composite Electrode Based on Simple Dipping Method

Directory of Open Access Journals (Sweden)

Kyoungho Kim

2015-01-01

Full Text Available As various wearable devices are emerging, self-generated power sources, such as piezoelectric generators, triboelectric generators, and thermoelectric generators, are of interest. To adapt self-generated power sources for application devices, a supercapacitor is necessary because of the short generation times (1–10 ms and low generated power (1–100 μW of self-generated power sources. However, to date, supercapacitors are too large to be adapted for wearable devices. There have been many efforts to reduce the size of supercapacitors by using polypyrrole (PPy for high energy supercapacitor electrodes. However, these supercapacitors have several disadvantages, such as a low operating voltage due to the use of an aqueous electrolyte, and complex manufacturing methods, such as the hydrogel and aerosol methods. In particular, the low operating voltage (~1.0 V is a significant issue because most electronic components operate above 3.0 V. In this study, we successfully demonstrated the high operating voltage (3.0 V of a supercapacitor using a PPy/activated carbon (AC composite electrode based on the chemical polymerization of the PPy by simple dipping. In addition, a twofold enhancement of its energy density was achieved compared with conventional supercapacitors using AC electrodes.

Chemical method of labelling proteins with the radionuclides of technetium at physiological condition

International Nuclear Information System (INIS)

Wong, D.W.

1983-01-01

A novel rapid chemical method of labeling plasma proteins, other compounds and/or substances containing protein with radionuclides of technetium such as sup(95m)Tc, sup(99m)Tc or sup(99)Tc at physiologic pH 7.4 condition, producing a sterile non-pyrogenic radioactive tracer material suitable for biological and medical uses. These radiolabeled protein substances are not denatured by the labeling process but retain their natural physiological and immunological properties. This novel labeling technique provides a simple and rapid means of labeling plasma proteins such as human serum albumin, fibrinogen, antibodies, hormones and enzymes with sup(95m)Tc or sup(99m)Tc for scintigraphic imaging which may allow visualization of thrombi, emboli, myocardial infarcts, infectious lesions or tumors

A simple transformation independent method for outlier definition.

Science.gov (United States)

Johansen, Martin Berg; Christensen, Peter Astrup

2018-04-10

Definition and elimination of outliers is a key element for medical laboratories establishing or verifying reference intervals (RIs). Especially as inclusion of just a few outlying observations may seriously affect the determination of the reference limits. Many methods have been developed for definition of outliers. Several of these methods are developed for the normal distribution and often data require transformation before outlier elimination. We have developed a non-parametric transformation independent outlier definition. The new method relies on drawing reproducible histograms. This is done by using defined bin sizes above and below the median. The method is compared to the method recommended by CLSI/IFCC, which uses Box-Cox transformation (BCT) and Tukey's fences for outlier definition. The comparison is done on eight simulated distributions and an indirect clinical datasets. The comparison on simulated distributions shows that without outliers added the recommended method in general defines fewer outliers. However, when outliers are added on one side the proposed method often produces better results. With outliers on both sides the methods are equally good. Furthermore, it is found that the presence of outliers affects the BCT, and subsequently affects the determined limits of current recommended methods. This is especially seen in skewed distributions. The proposed outlier definition reproduced current RI limits on clinical data containing outliers. We find our simple transformation independent outlier detection method as good as or better than the currently recommended methods.

Using container weights to determine irrigation needs: A simple method

Science.gov (United States)

R. Kasten Dumroese; Mark E. Montville; Jeremiah R. Pinto

2015-01-01

Proper irrigation can reduce water use, water waste, and incidence of disease. Knowing when to irrigate plants in container nurseries can be determined by weighing containers. This simple method is quantifiable, which is a benefit when more than one worker is responsible for irrigation. Irrigation is necessary when the container weighs some target as a proportion of...

Radiation transport benchmarks for simple geometries with void regions using the spherical harmonics method

International Nuclear Information System (INIS)

Kobayashi, K.

2009-01-01

In 2001, an international cooperation on the 3D radiation transport benchmarks for simple geometries with void region was performed under the leadership of E. Sartori of OECD/NEA. There were contributions from eight institutions, where 6 contributions were by the discrete ordinate method and only two were by the spherical harmonics method. The 3D spherical harmonics program FFT3 by the finite Fourier transformation method has been improved for this presentation, and benchmark solutions for the 2D and 3D simple geometries with void region by the FFT2 and FFT3 are given showing fairly good accuracy. (authors)

A Simple and Reliable Method of Design for Standalone Photovoltaic Systems

Science.gov (United States)

Srinivasarao, Mantri; Sudha, K. Rama; Bhanu, C. V. K.

2017-06-01

Standalone photovoltaic (SAPV) systems are seen as a promoting method of electrifying areas of developing world that lack power grid infrastructure. Proliferations of these systems require a design procedure that is simple, reliable and exhibit good performance over its life time. The proposed methodology uses simple empirical formulae and easily available parameters to design SAPV systems, that is, array size with energy storage. After arriving at the different array size (area), performance curves are obtained for optimal design of SAPV system with high amount of reliability in terms of autonomy at a specified value of loss of load probability (LOLP). Based on the array to load ratio (ALR) and levelized energy cost (LEC) through life cycle cost (LCC) analysis, it is shown that the proposed methodology gives better performance, requires simple data and is more reliable when compared with conventional design using monthly average daily load and insolation.

Simple measurement of 14C in the environment using gel suspension method

International Nuclear Information System (INIS)

Wakabayashi, Genichiro; Oura, Hirotaka; Nagao, Kenjiro; Okai, Tomio; Matoba, Masaru; Kakiuchi, Hideki; Momoshima, Noriyuki; Kawamura, Hidehisa

1999-01-01

A gel suspension method using N-lauroyl-L-glutamic-α, γ-dibutylamide as gelling agent and calcium carbonate as sample was studied and it was proved a more simple measurement method of 14 C in environment than the ordinary method. 100, 20 and 7 ml of sample could introduce 3.6, 0.72 and 0.252 g of carbon, respectively. When 100 ml and 20 ml of vial introduced the maximum carbon, the lower limit of detection was about 0.3 dpm/g-C and 0.5 dpm/g-C, respectively. These values showed that this method was able to determine 14 C in the environment. The value of sample has been constant for two years or more. This fact indicated the sample prepared by this method was good for repeat measurement and long-term storage. Many samples prepared by the same calcium carbonate showed almost same values. The concentrations of 14 C in the growth rings of a tree and in rice in the environment were determined and the results agreed with the values in the references. From these above results, this method is more simple measurement method of 14 C in the environment than the ordinary method and can apply to determine 14 C in and around the nuclear installation. (S.Y.)

A Simple and Effective Physical Characteristic Profiling Method for Methamphetamine Tablet Seized in China.

Science.gov (United States)

Li, Tao; Hua, Zhendong; Meng, Xin; Liu, Cuimei

2018-03-01

Methamphetamine (MA) tablet production confers chemical and physical properties. This study developed a simple and effective physical characteristic profiling method for MA tablets with capital letter "WY" logos, which realized the discrimination between linked and unlinked seizures. Seventeen signature distances extracted from the "WY" logo were explored as factors for multivariate analysis and demonstrated to be effective to represent the features of tablets in the drug intelligence perspective. Receiver operating characteristic (ROC) curve was used to evaluate efficiency of different pretreatments and distance/correlation metrics, while "Standardization + Euclidean" and "Logarithm + Euclidean" algorithms outperformed the rest. Finally, hierarchical cluster analysis (HCA) was applied to the data set of 200 MA tablet seizures randomly selected from cases all around China in 2015, and 76% of them were classified into a group named after "WY-001." Moreover, the "WY-001" tablets occupied 51-80% tablet seizures from 2011 to 2015 in China, indicating the existence of a huge clandestine factory incessantly manufacturing MA tablets. © 2017 American Academy of Forensic Sciences.

A simple enzymic method for the synthesis of [32P]phosphoenolpyruvate

International Nuclear Information System (INIS)

Parra, F.

1982-01-01

A rapid and simple enzymic method is described for the synthesis of [ 32 P]phosphoenolpyruvate from [ 32 P]Psub(i), with a reproducible yield of 74%. The final product was shown to be a good substrate for pyruvate kinase (EC 2.7.1.40). (author)

Simple method for the estimation of glomerular filtration rate

Energy Technology Data Exchange (ETDEWEB)

Groth, T [Group for Biomedical Informatics, Uppsala Univ. Data Center, Uppsala (Sweden); Tengstroem, B [District General Hospital, Skoevde (Sweden)

1977-02-01

A simple method is presented for indirect estimation of the glomerular filtration rate from two venous blood samples, drawn after a single injection of a small dose of (/sup 125/I)sodium iothalamate (10 ..mu..Ci). The method does not require exact dosage, as the first sample, taken after a few minutes (t=5 min) after injection, is used to normilize the value of the second sample, which should be taken in between 2 to 4 h after injection. The glomerular filtration rate, as measured by standard insulin clearance, may then be predicted from the logarithm of the normalized value and linear regression formulas with a standard error of estimate of the order of 1 to 2 ml/min/1.73 m/sup 2/. The slope-intercept method for direct estimation of glomerular filtration rate is also evaluated and found to significantly underestimate standard insulin clearance. The normalized 'single-point' method is concluded to be superior to the slope-intercept method and more sophisticated methods using curve fitting technique, with regard to predictive force and clinical applicability.

High-Performance Liquid Chromatography in the Undergraduate Chemical Engineering Laboratory

Science.gov (United States)

Frey, Douglas D.; Guo, Hui; Karnik, Nikhila

2013-01-01

This article describes the assembly of a simple, low-cost, high-performance liquid chromatography (HPLC) system and its use in the undergraduate chemical engineering laboratory course to perform simple experiments. By interpreting the results from these experiments students are able to gain significant experience in the general method of…

Chemical analysis and base-promoted hydrolysis of locally ...

African Journals Online (AJOL)

Abstract. The study was on the chemical analysis and base- promoted hydrolysis of extracted shea nut fat. The local method of extraction of the shea nut oil was employed in comparison with literature report. A simple cold-process alkali hydrolysis of the shea nut oil was used in producing the soap. The chemical analysis of ...

A simple method for purification of lipopolysaccharides from E. coli 55:B5 using size exclusion chromatography

International Nuclear Information System (INIS)

Perdomo, Rolando; Montero, Vivian

2006-01-01

Several methods for the extraction of endotoxin or lipopolysaccharide from Gram negative bacteria have been described. However, the product is often contaminated with nucleic acids or proteins in a proportion depending on the extraction method used. Molecular and immunological studies require further purification of the raw LPS. We present here, a simple method for the purification of raw LPS obtained by the standard hot phenol-water procedure using size exclusion chromatography in Sepharose CL-6B. We demonstrated that the using of DNAse and RNAse treatment of the sample before the chromatographic step is necessary to abrogate the nucleic acid contamination in the LPS fraction. The spectrophotometric properties of the pure LPS were verified, supporting the immediate online detection of the LPS and oligonucleotides fractions spectrophotometrically at 206 nm. The mobile phase used (NaCl 0.2 M) do not absorb at 206 nm while maintains the LPS aggregates and therefore, allows the separation of the LPS fraction from the oligoribonucleotide and desoxioligoribonucleotide fractions. The yield of pure LPS was around 98%. Chemical and biological characterizations were conducted in order to assess the feasibility of the procedure developed. (Author)

A simple method for generation of back-ground-free gamma-ray spectra

International Nuclear Information System (INIS)

Kawarasaki, Y.

1976-01-01

A simple and versatile method of generating background-free γ-ray spectra is presented. This method is equivalent to the generation of a continuous background baseline over the entire energy range of spectra corresponding to the original ones obtained with a Ge(Li) detector. These background curves can not be generally expressed in a single and simple analytic form nor in the form of a power series. These background-free spectra thus obtained make it feasible to assign many tiny peaks at the stage of visual inspection of the spectra, which is difficult to do with the original ones. The automatic peak-finding and peak area calculation procedures are both applicable to these background-free spectra. Examples of the application are illustrated. The effect of the peak-shape distortion is also discussed. (Auth.)

Recycling of poly(ethylene terephthalate – A review focusing on chemical methods

Directory of Open Access Journals (Sweden)

B. Geyer

2016-07-01

Full Text Available Recycling of poly(ethylene terephthalate (PET is of crucial importance, since worldwide amounts of PETwaste increase rapidly due to its widespread applications. Hence, several methods have been developed, like energetic, material, thermo-mechanical and chemical recycling of PET. Most frequently, PET-waste is incinerated for energy recovery, used as additive in concrete composites or glycolysed to yield mixtures of monomers and undefined oligomers. While energetic and thermo-mechanical recycling entail downcycling of the material, chemical recycling requires considerable amounts of chemicals and demanding processing steps entailing toxic and ecological issues. This review provides a thorough survey of PET-recycling including energetic, material, thermo-mechanical and chemical methods. It focuses on chemical methods describing important reaction parameters and yields of obtained reaction products. While most methods yield monomers, only a few yield undefined low molecular weight oligomers for impaired applications (dispersants or plasticizers. Further, the present work presents an alternative chemical recycling method of PET in comparison to existing chemical methods.

Simple Stacking Methods for Silicon Micro Fuel Cells

Directory of Open Access Journals (Sweden)

Gianmario Scotti

2014-08-01

Full Text Available We present two simple methods, with parallel and serial gas flows, for the stacking of microfabricated silicon fuel cells with integrated current collectors, flow fields and gas diffusion layers. The gas diffusion layer is implemented using black silicon. In the two stacking methods proposed in this work, the fluidic apertures and gas flow topology are rotationally symmetric and enable us to stack fuel cells without an increase in the number of electrical or fluidic ports or interconnects. Thanks to this simplicity and the structural compactness of each cell, the obtained stacks are very thin (~1.6 mm for a two-cell stack. We have fabricated two-cell stacks with two different gas flow topologies and obtained an open-circuit voltage (OCV of 1.6 V and a power density of 63 mW·cm−2, proving the viability of the design.

Simple method of obtaining the band strengths in the electronic spectra of diatomic molecules

International Nuclear Information System (INIS)

Gowda, L.S.; Balaji, V.N.

1977-01-01

It is shown that relative band strengths of diatomic molecules for which the product of Franck-Condon factor and r-centroid is approximately equal to 1 for (0,0) band can be determined by a simple method which is in good agreement with the smoothed array of experimental values. Such values for the Swan bands of the C 2 molecule are compared with the band strengths of the simple method. It is noted that the Swan bands are one of the outstanding features of R- and N-type stars and of the heads of comets

A Simple Combinatorial Codon Mutagenesis Method for Targeted Protein Engineering.

Science.gov (United States)

Belsare, Ketaki D; Andorfer, Mary C; Cardenas, Frida S; Chael, Julia R; Park, Hyun June; Lewis, Jared C

2017-03-17

Directed evolution is a powerful tool for optimizing enzymes, and mutagenesis methods that improve enzyme library quality can significantly expedite the evolution process. Here, we report a simple method for targeted combinatorial codon mutagenesis (CCM). To demonstrate the utility of this method for protein engineering, CCM libraries were constructed for cytochrome P450 BM3 , pfu prolyl oligopeptidase, and the flavin-dependent halogenase RebH; 10-26 sites were targeted for codon mutagenesis in each of these enzymes, and libraries with a tunable average of 1-7 codon mutations per gene were generated. Each of these libraries provided improved enzymes for their respective transformations, which highlights the generality, simplicity, and tunability of CCM for targeted protein engineering.

The simple method to co-register planar image with photograph

International Nuclear Information System (INIS)

Jang, Sung June; Kim, Seok Ki; Kang, Keon Wook

2005-01-01

Generally scintigraphic image presents the highly specific functional information. Sometimes, there can be limited information of patients anatomical landmark required to identify the lesion in planar nuclear medicine image. In this study, we applied the simple fusion method of planar scintigraphy and plain photography and validated the techniques with our own software. We used three fiducial marks which were comprised with Tc-99m. We obtained planar image with single head gamma camera (ARGUS ADAC laboratory, USA) and photograph using a general digital camera (CANON JAPAN). The coordinates of three marks were obtained in photograph and planar scintigraphy image. Based on these points, we took affine transformation and then fused these two images. To evaluate the precision, we compared with different depth. To find out the depth of lesion, the images were acquired in different angles and we compared the real depth and the geometrically calculated depth. At the same depth with mark, the each discordance was less than 1 mm. When the photograph were taken at the distance with 1 m and 2 m, the point 30 cm off the center were discordant in 5 mm and 2 mm each. We used this method in the localization of the remnant thyroid tissue on I-131 whole body scan with photo image. The simple method to co-register planar image with photography was reliable and easy to use. By this method, we could localize the lesion on the planar scintigraphy more accurately with other planar images (i.e. photograph) and predict the depth of the lesion without tomographic image

Multiscale methods coupling atomistic and continuum mechanics: analysis of a simple case

OpenAIRE

Blanc , Xavier; Le Bris , Claude; Legoll , Frédéric

2007-01-01

International audience; The description and computation of fine scale localized phenomena arising in a material (during nanoindentation, for instance) is a challenging problem that has given birth to many multiscale methods. In this work, we propose an analysis of a simple one-dimensional method that couples two scales, the atomistic one and the continuum mechanics one. The method includes an adaptive criterion in order to split the computational domain into two subdomains, that are described...

A Simple Method to Calculate the Temperature Dependence of the Gibbs Energy and Chemical Equilibrium Constants

Science.gov (United States)

Vargas, Francisco M.

2014-01-01

The temperature dependence of the Gibbs energy and important quantities such as Henry's law constants, activity coefficients, and chemical equilibrium constants is usually calculated by using the Gibbs-Helmholtz equation. Although, this is a well-known approach and traditionally covered as part of any physical chemistry course, the required…

A simple method for affinity purification of radiolabeled monoclonal antibodies

Energy Technology Data Exchange (ETDEWEB)

Juweid, M; Sato, J; Paik, C; Onay-Basaran, S; Weinstein, J N; Neumann, R D [National Cancer Inst., Bethesda, MD (United States)

1993-04-01

A simple method is described for affinity purification of radiolabeled antibodies using glutaraldehyde-fixed tumor target cells. The cell-bound antibody fraction is removed from the cells by an acid wash and then immediately subjected to buffer-exchange chromatography. The method was applied to the D3 murine monoclonal antibody which binds to a 290 kDa antigen on the surface of Line 10 guinea pig carcinoma cells. No alteration in the molecular size profile was detected after acid washing. Purification resulted in a significant increase in immunoreactivity by an average of 14 [+-] 47% (SD; range 4-30%). (author).

VBSCF Methods: Classical Chemical Concepts and Beyond

NARCIS (Netherlands)

Rashid, Z.

2013-01-01

The aim of this research has been to extend the ab initio Valence Bond Self-Consistent Field (VBSCF) methodology and to apply this method to the electronic structure of molecules. The valence bond method directly deals with the chemical structure of molecules in a pictorial language, which chemists

Nonlinear Hamiltonian mechanics applied to molecular dynamics theory and computational methods for understanding molecular spectroscopy and chemical reactions

CERN Document Server

Farantos, Stavros C

2014-01-01

This brief presents numerical methods for describing and calculating invariant phase space structures, as well as solving the classical and quantum equations of motion for polyatomic molecules. Examples covered include simple model systems to realistic cases of molecules spectroscopically studied. Vibrationally excited and reacting molecules are nonlinear dynamical systems, and thus, nonlinear mechanics is the proper theory to elucidate molecular dynamics by investigating invariant structures in phase space. Intramolecular energy transfer, and the breaking and forming of a chemical bond have now found a rigorous explanation by studying phase space structures.

A simple method of screening for metabolic bone disease

International Nuclear Information System (INIS)

Broughton, R.B.K.; Evans, W.D.

1982-01-01

The purpose of this investigation was to find a simple method -to be used as an adjunct to the conventional bone scintigram- that could differentiate between decreased bone metabolism or mass, i.e., osteoporosis -normal bone- and the group of conditions of increased bone metabolism or mass namely, osteomalacia, renal osteodystrophy, hyperparathyroidism and Paget's disease. The Fogelman's method using the bone to soft tissue ratios from region of interest analysis at 4 hours post injection, was adopted. An initial experience in measuring a value for the count rate density in lumbar vertebrae at 1 hr post injection during conventional bone scintigraphy appears to give a clear indication of the overall rate of bone metabolism. The advantage over whole body retention methods is that the scan performed at the end of the metabolic study will reveal localized bone disease that may otherwise not be anticipated

Exploring simple assessment methods for lighting quality with architecture and design students

DEFF Research Database (Denmark)

Madsen, Merete

2006-01-01

that cannot be assessed by simple equations or rules-of-thumb. Balancing the many an often contradictory aspects of energy efficiency and high quality lighting design is a complex undertaking not just for students. The work described in this paper is one result of an academic staff exchange between...... the Schools of Architecture in Copenhagen and Victoria University of Wellington (New Zealand). The authors explore two approaches to teaching students simple assessment methods that can contribute to making more informed decisions about the luminous environment and its quality. One approach deals...... with the assessment of luminance ratios in relation to computer work and presents in that context some results from an experiment undertaken to introduce the concept of luminance ratios and preferred luminance ranges to architeture students. In the other approach a Danish method for assissing the luminance...

New method for estimating clustering of DNA lesions induced by physical/chemical mutagens using fluorescence anisotropy.

Science.gov (United States)

Akamatsu, Ken; Shikazono, Naoya; Saito, Takeshi

2017-11-01

We have developed a new method for estimating the localization of DNA damage such as apurinic/apyrimidinic sites (APs) on DNA using fluorescence anisotropy. This method is aimed at characterizing clustered DNA damage produced by DNA-damaging agents such as ionizing radiation and genotoxic chemicals. A fluorescent probe with an aminooxy group (AlexaFluor488) was used to label APs. We prepared a pUC19 plasmid with APs by heating under acidic conditions as a model for damaged DNA, and subsequently labeled the APs. We found that the observed fluorescence anisotropy (r obs ) decreases as averaged AP density (λ AP : number of APs per base pair) increases due to homo-FRET, and that the APs were randomly distributed. We applied this method to three DNA-damaging agents, 60 Co γ-rays, methyl methanesulfonate (MMS), and neocarzinostatin (NCS). We found that r obs -λ AP relationships differed significantly between MMS and NCS. At low AP density (λ AP  < 0.001), the APs induced by MMS seemed to not be closely distributed, whereas those induced by NCS were remarkably clustered. In contrast, the AP clustering induced by 60 Co γ-rays was similar to, but potentially more likely to occur than, random distribution. This simple method can be used to estimate mutagenicity of ionizing radiation and genotoxic chemicals. Copyright © 2017 Elsevier Inc. All rights reserved.

12 CFR 717.25 - Reasonable and simple methods of opting out.

Science.gov (United States)

2010-01-01

... simple methods for exercising an opt-out right do not include— (i) Requiring the consumer to write his or... out. (a) In general. You must not use eligibility information about a consumer that you receive from an affiliate to make a solicitation to the consumer about your products or services, unless the...

A simple red-ox titrimetric method for the evaluation of photo ...

Indian Academy of Sciences (India)

Unknown

tal conditions in a relatively short duration in R&D labora- tories having basic analytical facilities. The method suggested here could also be adopted to study the photo- catalytic activity of other transition metal oxide based catalysts. For establishing this technique, we have moni- tored a simple one-electron transfer red-ox ...

A simple method for the prevention of endometrial autolysis in hysterectomy specimens

OpenAIRE

Houghton, J P; Roddy, S; Carroll, S; McCluggage, W G

2004-01-01

Aims: Uteri are among the most common surgical pathology specimens. Assessment of the endometrium is often difficult because of pronounced tissue autolysis. This study describes a simple method to prevent endometrial autolysis and aid in interpretation of the endometrium.

A simple method for estimating the entropy of neural activity

International Nuclear Information System (INIS)

Berry II, Michael J; Tkačik, Gašper; Dubuis, Julien; Marre, Olivier; Da Silveira, Rava Azeredo

2013-01-01

The number of possible activity patterns in a population of neurons grows exponentially with the size of the population. Typical experiments explore only a tiny fraction of the large space of possible activity patterns in the case of populations with more than 10 or 20 neurons. It is thus impossible, in this undersampled regime, to estimate the probabilities with which most of the activity patterns occur. As a result, the corresponding entropy—which is a measure of the computational power of the neural population—cannot be estimated directly. We propose a simple scheme for estimating the entropy in the undersampled regime, which bounds its value from both below and above. The lower bound is the usual ‘naive’ entropy of the experimental frequencies. The upper bound results from a hybrid approximation of the entropy which makes use of the naive estimate, a maximum entropy fit, and a coverage adjustment. We apply our simple scheme to artificial data, in order to check their accuracy; we also compare its performance to those of several previously defined entropy estimators. We then apply it to actual measurements of neural activity in populations with up to 100 cells. Finally, we discuss the similarities and differences between the proposed simple estimation scheme and various earlier methods. (paper)

[Bioinorganic chemical composition of the lens and methods of its investigation].

Science.gov (United States)

Avetisov, S E; Novikov, I A; Pakhomova, N A; Motalov, V G

2018-01-01

Bioinorganic chemical composition of the lens of human and experimental animals (cows, dogs, rats, rabbits) have been analyzed in various studies. In most cases, the studies employed different methods to determine the gross (total) composition of chemical elements and their concentrations in the examined samples. Less frequently, they included an assessment of the distribution of chemical elements in the lens and correlation of their concentration with its morphological changes. Chemical elements from all groups (series) of the periodic classification system were discovered in the lens substance. Despite similar investigation methods, different authors obtained contradicting results on the chemical composition of the lens. This article presents data suggesting possible correlation between inorganic chemical elements in the lens substance with the development and formation of lenticular opacities. All currently employed methods are known to only analyze limited number of select chemical elements in the tissues and do not consider the whole range of elements that can be analyzed with existing technology; furthermore, the majority of studies are conducted on the animal model lens. Therefore, it is feasible to continue the development of the chemical microanalysis method by increasing the sensitivity of Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM/EDS) with the purpose of assessing the gross chemical composition and distribution of the elements in the lens substance, as well as revealing possible correlation between element concentration and morphological changes in the lens.

A simple method of fabricating mask-free microfluidic devices for biological analysis.

KAUST Repository

Yi, Xin; Kodzius, Rimantas; Gong, Xiuqing; Xiao, Kang; Wen, Weijia

2010-01-01

We report a simple, low-cost, rapid, and mask-free method to fabricate two-dimensional (2D) and three-dimensional (3D) microfluidic chip for biological analysis researches. In this fabrication process, a laser system is used to cut through paper

Method of cleaning oil slicks and chemical spills

International Nuclear Information System (INIS)

Billings, L.

1992-01-01

This patent describes a method of cleaning a floating chemical spill on a body of water. It comprises: providing a quantity of popular bark-based pelleted or granular product, flotation means and a flexible net having openings generally smaller than the smallest whole pellet dimension of the pelleted product, spreading the net over a chemical spill on the body of water, connecting the floatation means to the net thereby supporting the net adjacent the surface of the body of water, placing the poplar bark-based product on the net, absorbing the floating chemical spill into the product, and removing the chemical soaked product from the body of water

Calculation of Multiphase Chemical Equilibrium by the Modified RAND Method

DEFF Research Database (Denmark)

Tsanas, Christos; Stenby, Erling Halfdan; Yan, Wei

2017-01-01

method. The modified RAND extends the classical RAND method from single-phase chemical reaction equilibrium of ideal systems to multiphase chemical equilibrium of nonideal systems. All components in all phases are treated in the same manner and the system Gibbs energy can be used to monitor convergence....... This is the first time that modified RAND was applied to multiphase chemical equilibrium systems. The combined algorithm was tested using nine examples covering vapor–liquid (VLE) and vapor–liquid–liquid equilibria (VLLE) of ideal and nonideal reaction systems. Successive substitution provided good initial......A robust and efficient algorithm for simultaneous chemical and phase equilibrium calculations is proposed. It combines two individual nonstoichiometric solving procedures: a nested-loop method with successive substitution for the first steps and final convergence with the second-order modified RAND...

Feasibility of testing DNA repair inhibitors for mutagenicity by a simple method

International Nuclear Information System (INIS)

Sideropoulos, A.S.; Specht, S.M.; Jones, M.T.

1980-01-01

A simple screening methodology for the determination of mutagenicity of DNA repair inhibitors has been tested in this laboratory. Radiation-resistant E. coli B/r and WP2 hcr + and hcr - are suitable strains for mutagenicity testing. In these strains irradiated with 40-60 ergs/mm 2 , chemicals which interfere with repair of ultraviolet-induced pre-mutational lesions can be shown to enhance significantly the frequency of mutations to streptomycin resistance. This phenomenon is termed 'mutational synergism' [18,20]. We have attempted to apply the procedure for securing data for 'mutational synergism' between ultraviolet (UV) radiation and a number of antimalarial drugs including quinine hydrochloride (50 μg/ml), quinine hydrobromide (50 μg/ml), primaquine diphosphate (50 μg/ml), chloroquine (50 μg/ml), quinine (50 μg/ml) and quinacrine dihydrochloride (25 μg/ml). All drugs tested give synergistic effects with UV light. The synergistic activity ranges from 3- to 35-fold. Quinine and quinacrine dihydrochloride have been found to be much more efficient enhancers of the mutagenic effect of UV than caffeine. In general, we have found that the expression of synergistic action occurs at a concentration well below the minimum inhibitory concentration (MIC) with the drugs tested. The implication of these observations in the establishment of a screening method for the evaluation of the mutagenicity of DNA repair inhibitors is discussed. (orig.)

Feasibility of testing DNA repair inhibitors for mutagenicity by a simple method

International Nuclear Information System (INIS)

Sideropoulos, A.S.; Specht, S.M.; Jones, M.T.

1980-01-01

A simple screening methodology for the determination of mutagenictity of DNA repair inhibitors has been tested in this laboratory. Radiation-resistant E. coli B/r and WP2 hcr + and hcr - are suitable strains for mutagenicity testing. In these strains irradiated with 40-60 ergs/mm 2 , chemicals which interfere with repair of ultraviolet-induced pre-mutational lesions can be shown to enhance significantly the frequency of mutations to streptomycin resistance. This phenomenon is termed mutational synergism. We have attempted to apply the procedure for securing data for mutational synergism between ultraviolet (UV) radiation and a number of antimalarial drugs including quinine hydrochloride (50 μg/ml), quinine hydrobromide (50 μg/ml), primaquine diphosphate (50 μg/ml), chloroquine (50μg/ml) and quinacrine dihydrochloride (25 μg/ml). All drugs tested give synergistic effets with UV light. The synergistic activity ranges from 3- to 35-fold. Quinine and quinacrine dihydrochloride have been found to be much more efficient enhancers of the mutagenic effect of UV than caffeine. In general, we have found that the expression of synergistic action occurs at a concentration well below the minimum inhibitory concentration (MIC) with the drugs tested. The implication of these observations in the establishment of a screening method for the evaluation of the mutagenicity of DNA repair inhibitors is discussed. (orig.)

Feasibility of testing DNA repair inhibitors for mutagenicity by a simple method

Energy Technology Data Exchange (ETDEWEB)

Sideropoulos, A S; Specht, S M; Jones, M T [Duquesne Univ., Pittsburgh, PA (USA). Dept. of Biological Sciences

1980-04-01

A simple screening methodology for the determination of mutagenictity of DNA repair inhibitors has been tested in this laboratory. Radiation-resistant E. coli B/r and WP2 hcr/sup +/ and hcr/sup -/ are suitable strains for mutagenicity testing. In these strains irradiated with 40-60 ergs/mm/sup 2/, chemicals which interfere with repair of ultraviolet-induced pre-mutational lesions can be shown to enhance significantly the frequency of mutations to streptomycin resistance. This phenomenon is termed mutational synergism. We have attempted to apply the procedure for securing data for mutational synergism between ultraviolet (uv) radiation and a number of antimalarial drugs including quinine hydrochloride (50 ..mu..g/ml), quinine hydrobromide (50 ..mu..g/ml), primaquine diphosphate (50 ..mu..g/ml), chloroquine (50..mu..g/ml) and quinacrine dihydrochloride (25 ..mu..g/ml). All drugs tested give synergistic effects with uv light. The synergistic activity ranges from 3- to 35-fold. Quinine and quinacrine dihydrochloride have been found to be much more efficient enhancers of the mutagenic effect of uv than caffeine. In general, we have found that the expression of synergistic action occurs at a concentration well below the minimum inhibitory concentration (MIC) with the drugs tested. The implication of these observations in the establishment of a screening method for the evaluation of the mutagenicity of DNA repair inhibitors is discussed.

Feasibility of testing DNA repair inhibitors for mutagenicity by a simple method

Energy Technology Data Exchange (ETDEWEB)

Sideropoulos, A S; Specht, S M; Jones, M T [Duquesne Univ., Pittsburgh, PA (USA). Dept. of Biological Sciences

1980-04-01

A simple screening methodology for the determination of mutagenicity of DNA repair inhibitors has been tested in this laboratory. Radiation-resistant E. coli B/r and WP2 hcr/sup +/ and hcr/sup -/ are suitable strains for mutagenicity testing. In these strains irradiated with 40-60 ergs/mm/sup 2/, chemicals which interfere with repair of ultraviolet-induced pre-mutational lesions can be shown to enhance significantly the frequency of mutations to streptomycin resistance. This phenomenon is termed 'mutational synergism' (18,20). We have attempted to apply the procedure for securing data for 'mutational synergism' between ultraviolet (UV) radiation and a number of antimalarial drugs including quinine hydrochloride (50 ..mu..g/ml), quinine hydrobromide (50 ..mu..g/ml), primaquine diphosphate (50 ..mu..g/ml), chloroquine (50 ..mu..g/ml), quinine (50 ..mu..g/ml) and quinacrine dihydrochloride (25 ..mu..g/ml). All drugs tested give synergistic effects with UV light. The synergistic activity ranges from 3- to 35-fold. Quinine and quinacrine dihydrochloride have been found to be much more efficient enhancers of the mutagenic effect of UV than caffeine. In general, we have found that the expression of synergistic action occurs at a concentration well below the minimum inhibitory concentration (MIC) with the drugs tested. The implication of these observations in the establishment of a screening method for the evaluation of the mutagenicity of DNA repair inhibitors is discussed.

Use of eddy-covariance methods to "calibrate" simple estimators of evapotranspiration

Science.gov (United States)

Sumner, David M.; Geurink, Jeffrey S.; Swancar, Amy

2017-01-01

Direct measurement of actual evapotranspiration (ET) provides quantification of this large component of the hydrologic budget, but typically requires long periods of record and large instrumentation and labor costs. Simple surrogate methods of estimating ET, if “calibrated” to direct measurements of ET, provide a reliable means to quantify ET. Eddy-covariance measurements of ET were made for 12 years (2004-2015) at an unimproved bahiagrass (Paspalum notatum) pasture in Florida. These measurements were compared to annual rainfall derived from rain gage data and monthly potential ET (PET) obtained from a long-term (since 1995) U.S. Geological Survey (USGS) statewide, 2-kilometer, daily PET product. The annual proportion of ET to rainfall indicates a strong correlation (r2=0.86) to annual rainfall; the ratio increases linearly with decreasing rainfall. Monthly ET rates correlated closely (r2=0.84) to the USGS PET product. The results indicate that simple surrogate methods of estimating actual ET show positive potential in the humid Florida climate given the ready availability of historical rainfall and PET.

Validity of a Simple Method for Measuring Force-Velocity-Power Profile in Countermovement Jump.

Science.gov (United States)

Jiménez-Reyes, Pedro; Samozino, Pierre; Pareja-Blanco, Fernando; Conceição, Filipe; Cuadrado-Peñafiel, Víctor; González-Badillo, Juan José; Morin, Jean-Benoît

2017-01-01

To analyze the reliability and validity of a simple computation method to evaluate force (F), velocity (v), and power (P) output during a countermovement jump (CMJ) suitable for use in field conditions and to verify the validity of this computation method to compute the CMJ force-velocity (F-v) profile (including unloaded and loaded jumps) in trained athletes. Sixteen high-level male sprinters and jumpers performed maximal CMJs under 6 different load conditions (0-87 kg). A force plate sampling at 1000 Hz was used to record vertical ground-reaction force and derive vertical-displacement data during CMJ trials. For each condition, mean F, v, and P of the push-off phase were determined from both force-plate data (reference method) and simple computation measures based on body mass, jump height (from flight time), and push-off distance and used to establish the linear F-v relationship for each individual. Mean absolute bias values were 0.9% (± 1.6%), 4.7% (± 6.2%), 3.7% (± 4.8%), and 5% (± 6.8%) for F, v, P, and slope of the F-v relationship (S Fv ), respectively. Both methods showed high correlations for F-v-profile-related variables (r = .985-.991). Finally, all variables computed from the simple method showed high reliability, with ICC >.980 and CV push-off distance, and jump height are known.

A simple method of chaos control for a class of chaotic discrete-time systems

International Nuclear Information System (INIS)

Jiang Guoping; Zheng Weixing

2005-01-01

In this paper, a simple method is proposed for chaos control for a class of discrete-time chaotic systems. The proposed method is built upon the state feedback control and the characteristic of ergodicity of chaos. The feedback gain matrix of the controller is designed using a simple criterion, so that control parameters can be selected via the pole placement technique of linear control theory. The new controller has a feature that it only uses the state variable for control and does not require the target equilibrium point in the feedback path. Moreover, the proposed control method cannot only overcome the so-called 'odd eigenvalues number limitation' of delayed feedback control, but also control the chaotic systems to the specified equilibrium points. The effectiveness of the proposed method is demonstrated by a two-dimensional discrete-time chaotic system

12 CFR 571.25 - Reasonable and simple methods of opting out.

Science.gov (United States)

2010-01-01

... CREDIT REPORTING Affiliate Marketing § 571.25 Reasonable and simple methods of opting out. (a) In general... out, such as a form that can be electronically mailed or processed at an Internet Web site, if the... (15 U.S.C. 6801 et seq.), the affiliate sharing opt-out under the Act, and the affiliate marketing opt...

16 CFR 680.25 - Reasonable and simple methods of opting out.

Science.gov (United States)

2010-01-01

... AFFILIATE MARKETING § 680.25 Reasonable and simple methods of opting out. (a) In general. You must not use... a form that can be electronically mailed or processed at an Internet Web site, if the consumer..., 15 U.S.C. 6801 et seq., the affiliate sharing opt-out under the Act, and the affiliate marketing opt...

A Simple Method to Measure Nematodes' Propulsive Thrust and the Nematode Ratchet.

Science.gov (United States)

Bau, Haim; Yuan, Jinzhou; Raizen, David

2015-11-01

Since the propulsive thrust of micro organisms provides a more sensitive indicator of the animal's health and response to drugs than motility, a simple, high throughput, direct measurement of the thrust is desired. Taking advantage of the nematode C. elegans being heavier than water, we devised a simple method to determine the propulsive thrust of the animals by monitoring their velocity when swimming along an inclined plane. We find that the swimming velocity is a linear function of the sin of the inclination angle. This method allows us to determine, among other things, the animas' propulsive thrust as a function of genotype, drugs, and age. Furthermore, taking advantage of the animals' inability to swim over a stiff incline, we constructed a sawteeth ratchet-like track that restricts the animals to swim in a predetermined direction. This research was supported, in part, by NIH NIA Grant 5R03AG042690-02.

A simple method for determining the lattice parameter and chemical composition in ternary bcc-Fe rich nanocrystals

International Nuclear Information System (INIS)

Moya, Javier A.; Gamarra Caramella, Soledad; Marta, Leonardo J.; Berejnoi, Carlos

2015-01-01

Highlights: • A method for determining composition in ternary nanocrystals is presented. • X-ray diffraction and Mössbauer spectroscopy data were employed. • We perform theoretical charts for lattice parameter of Fe-rich ternary alloys. • A linear relationship in lattice parameter for binary alloys is evaluated. • A parabolic relationship is proposed for the Fe–Co–Si alloy. - Abstract: Charts containing lattice parameters of Fe 1−x (M,N) x ternary systems with M and N = Si, Al, Ge or Co, and 0 ⩽ x ⩽ ∼0.3, were developed by implementing a linear relationship between the respective binary alloys with the same solute content of the ternary one. Charts were validated with experimental data obtained from literature. For the Fe–Co–Si system, the linear relationship does not fit the experimental data. For the other systems (except the Fe–Co–Ge one where no experimental data was found), the lineal relationship constitute a very good approximation. Using these charts and the lattice parameter data obtained from X-ray diffraction technique combining with the solute content data obtained from Mössbauer spectroscopy technique it is possible to determine the chemical composition of nanograins in soft magnetic nanocomposite materials and some examples are provided

A simple method for determining the lattice parameter and chemical composition in ternary bcc-Fe rich nanocrystals

Energy Technology Data Exchange (ETDEWEB)

Moya, Javier A., E-mail: jmoya.fi.uba@gmail.com [Grupo Interdisciplinario en Materiales-IESIING, Universidad Católica de Salta, INTECIN UBA-CONICET, Salta (Argentina); Gamarra Caramella, Soledad; Marta, Leonardo J. [Grupo Interdisciplinario en Materiales-IESIING, Universidad Católica de Salta, INTECIN UBA-CONICET, Salta (Argentina); Berejnoi, Carlos [Universidad Nacional de Salta, Facultad de Ingeniería, Salta (Argentina)

2015-05-15

Highlights: • A method for determining composition in ternary nanocrystals is presented. • X-ray diffraction and Mössbauer spectroscopy data were employed. • We perform theoretical charts for lattice parameter of Fe-rich ternary alloys. • A linear relationship in lattice parameter for binary alloys is evaluated. • A parabolic relationship is proposed for the Fe–Co–Si alloy. - Abstract: Charts containing lattice parameters of Fe{sub 1−x}(M,N){sub x} ternary systems with M and N = Si, Al, Ge or Co, and 0 ⩽ x ⩽ ∼0.3, were developed by implementing a linear relationship between the respective binary alloys with the same solute content of the ternary one. Charts were validated with experimental data obtained from literature. For the Fe–Co–Si system, the linear relationship does not fit the experimental data. For the other systems (except the Fe–Co–Ge one where no experimental data was found), the lineal relationship constitute a very good approximation. Using these charts and the lattice parameter data obtained from X-ray diffraction technique combining with the solute content data obtained from Mössbauer spectroscopy technique it is possible to determine the chemical composition of nanograins in soft magnetic nanocomposite materials and some examples are provided.

Effect of Araxa rockphosphate and simple superphosphate on some physico-chemical properties and on the available residual P of an oxic Paleudalf

International Nuclear Information System (INIS)

Urquiaga C, S.; Reichardt, K.; Libardi, P.L.

The experiment was developed using soil samples (TRE, Oxic Paleudalfs) from the Experimental Field Station of ESALQ, located in Piracicaba, SP, Brazil. This soil had received during the period of three years 6 ton/ha of Araxa Rockphosphate (34.6% P 2 O 5 ) or 0.5 ton/ha of Simple Superphosphate (20% P 2 O 5 ) while three crops of beans (Phaseolus vulgaris, L.) were grown. This greenhouse experiment had the objective of evaluating the effect of these fertilizer applications on some physico-chemical properties of the soil, and also study the residual P effect through the Olsen and 'A value' methods. Results indicate that Araxa Rockphosphate (48.4% CaO), although applied at high rate, did not affect soil reaction. On the other hand, both fertilizers increased the exchangeable Ca 2+ level in approximately 0.5 me/100 g. In short therm (less than 3 years), the response of Araxa Rockphosphate corresponded to its 2% citric acid soluble P 2 O 5 content (4%) rather than to its total P 2 O 5 content. Through 'A values' (using KH 2 32 PO 4 ) it was shown that the residual effect of Simple Superphosphate (108.6 Kg P 2 O 5 /ha) was similar to the Araxa Rockphosphate (136.6 Kg P 2 O 5 /ha), but these were significantly greater than the natural P content of the soil (54.0 Kg P 2 O 5 /ha). The evaluation of available P in the soil (with and without fertilizer) by Olsen's method, had and efficiency of 64 and 94% (respectively) as compared to the 'A value' method. (Author) [pt

A simple and fast method for extraction and quantification of cryptophyte phycoerythrin

OpenAIRE

Thoisen, Christina; Hansen, Benni Winding; Nielsen, S?ren Laurentius

2017-01-01

The microalgal pigment phycoerythrin (PE) is of commercial interest as natural colorant in food and cosmetics, as well as fluoroprobes for laboratory analysis. Several methods for extraction and quantification of PE are available but they comprise typically various extraction buffers, repetitive freeze-thaw cycles and liquid nitrogen, making extraction procedures more complicated. A simple method for extraction of PE from cryptophytes is described using standard laboratory materials and equip...

Present status and future of simple measuring methods; Suishitsu kan`i sokutei gijutsu no genjo to hatten no hoko

Energy Technology Data Exchange (ETDEWEB)

Urano, K.; Ishii, S. [Yokohama National University, Yokohama (Japan)

1998-05-10

This paper discusses simple measuring methods for water quality. There are various purposes for measuring water quality. It is not necessary to measure the water quality in an official way by taking a lot of labor and cost. Simple measuring methods are often adopted. By applying simple methods, measuring points and frequency of main discharge processes can be increased, resulting in the detailed evaluation and monitoring. Easy safety check for earth filling waste and soil pollutants is realized. Daily inspection and atmospheric measurements at accidents and disasters are easily promoted. The simple methods require easy and rapid operation, sensibility, accuracy and reproducibility suitable for the purpose, small size apparatus, low cost for measurements, and safety against used harmful matters. Coloring reaction is utilized for most of the measuring principles of simple methods, which include tests using test papers, pack tests, colorimetric tests, and tests using photoelectric colorimeter. The bacteria detection includes titration methods using dropping bottles, tablets and syringes, and tests using test papers. A measuring kit for the enzyme immunity method is commercialized. Cooperation of experts, measuring operators at the site and citizens is also indispensable. 7 refs., 3 figs., 2 tabs.

Chemical decontamination method

International Nuclear Information System (INIS)

Nishiwaki, Hitoshi.

1996-01-01

Metal wastes contaminated by radioactive materials are contained in a rotational decontamination vessel, and the metal wastes are rotated therein while being in contact with a slight amount of a decontamination liquid comprising a mineral acid. As the mineral acid, a mixed acid of nitric acid, hydrochloric acid and fluoric acid is preferably used. Alternatively, chemical decontamination can also be conducted by charging an acid resistant stirring medium in the rotational decontamination vessel. The surface of the metal wastes is uniformly covered by the slight amount of decontamination liquid to dissolve the surface layer. In addition, heat of dissolution generated in this case is accumulated in the inside of the rotational decontamination vessel, the temperature is elevated with no particular heating, thereby enabling to obtain an excellent decontamination effect substantially at the same level as in the case of heating the liquid to 70degC in a conventional immersion decontamination method. Further, although contact areas between the metal wastes and the immersion vessel are difficult to be decontaminated in the immersion decontamination method, all of areas can be dissolved uniformly in the present invention. (T.M.)

Simple method for absolute calibration of geophones, seismometers, and other inertial vibration sensors

International Nuclear Information System (INIS)

Kann, Frank van; Winterflood, John

2005-01-01

A simple but powerful method is presented for calibrating geophones, seismometers, and other inertial vibration sensors, including passive accelerometers. The method requires no cumbersome or expensive fixtures such as shaker platforms and can be performed using a standard instrument commonly available in the field. An absolute calibration is obtained using the reciprocity property of the device, based on the standard mathematical model for such inertial sensors. It requires only simple electrical measurement of the impedance of the sensor as a function of frequency to determine the parameters of the model and hence the sensitivity function. The method is particularly convenient if one of these parameters, namely the suspended mass is known. In this case, no additional mechanical apparatus is required and only a single set of impedance measurements yields the desired calibration function. Moreover, this measurement can be made with the device in situ. However, the novel and most powerful aspect of the method is its ability to accurately determine the effective suspended mass. For this, the impedance measurement is made with the device hanging from a simple spring or flexible cord (depending on the orientation of its sensitive axis). To complete the calibration, the device is weighed to determine its total mass. All the required calibration parameters, including the suspended mass, are then determined from a least-squares fit to the impedance as a function of frequency. A demonstration using both a 4.5 Hz geophone and a 1 Hz seismometer shows that the method can yield accurate absolute calibrations with an error of 0.1% or better, assuming no a priori knowledge of any parameters

Simple spectrophotometry method for the determination of sulfur dioxide in an alcohol-thionyl chloride reaction

Energy Technology Data Exchange (ETDEWEB)

Zheng, Jinjian, E-mail: jinjian.zheng@merck.com; Tan, Feng; Hartman, Robert

2015-09-03

negligible UV absorbance at 276 nm, and the UV absorbance is attributed only to sample matrix. Quantitation of sulfur dioxide is achieved by subtracting the UV absorbance of sample solution at pH 4.0 from that at pH 1.3. The method is simple but sensitive, with a limit of quantitation of 80 μg L{sup −1}. The method linearity was demonstrated from 2 mg L{sup −1} to 40 mg L{sup −1} with an R{sup 2} of 0.998, and the spiked recovery ranges from 94% to 105% within the same range. The results are comparable with those obtained using inductively coupled plasma–atomic emission spectrometry (ICP–AES) and gas chromatography–mass spectrometry (GC–MS), suggesting that this method is accurate. - Highlights: • Simple UV spectrometry method to quantitate sulfur dioxide in complex matrix. • Excellent sensitivity, linearity and accuracy. • Potential for real time monitoring using process analytical technology. • Possible applications in chemical, pharmaceutical, beverage and wine industries.

A Comparison of Multidimensional Item Selection Methods in Simple and Complex Test Designs

Directory of Open Access Journals (Sweden)

Eren Halil ÖZBERK

2017-03-01

Full Text Available In contrast with the previous studies, this study employed various test designs (simple and complex which allow the evaluation of the overall ability score estimations across multiple real test conditions. In this study, four factors were manipulated, namely the test design, number of items per dimension, correlation between dimensions and item selection methods. Using the generated item and ability parameters, dichotomous item responses were generated in by using M3PL compensatory multidimensional IRT model with specified correlations. MCAT composite ability score accuracy was evaluated using absolute bias (ABSBIAS, correlation and the root mean square error (RMSE between true and estimated ability scores. The results suggest that the multidimensional test structure, number of item per dimension and correlation between dimensions had significant effect on item selection methods for the overall score estimations. For simple structure test design it was found that V1 item selection has the lowest absolute bias estimations for both long and short tests while estimating overall scores. As the model gets complex KL item selection method performed better than other two item selection method.

Simple, reliable, and nondestructive method for the measurement of vacuum pressure without specialized equipment.

Science.gov (United States)

Yuan, Jin-Peng; Ji, Zhong-Hua; Zhao, Yan-Ting; Chang, Xue-Fang; Xiao, Lian-Tuan; Jia, Suo-Tang

2013-09-01

We present a simple, reliable, and nondestructive method for the measurement of vacuum pressure in a magneto-optical trap. The vacuum pressure is verified to be proportional to the collision rate constant between cold atoms and the background gas with a coefficient k, which can be calculated by means of the simple ideal gas law. The rate constant for loss due to collisions with all background gases can be derived from the total collision loss rate by a series of loading curves of cold atoms under different trapping laser intensities. The presented method is also applicable for other cold atomic systems and meets the miniaturization requirement of commercial applications.

A New Pseudoinverse Matrix Method For Balancing Chemical Equations And Their Stability

International Nuclear Information System (INIS)

Risteski, Ice B.

2008-01-01

In this work is given a new pseudoniverse matrix method for balancing chemical equations. Here offered method is founded on virtue of the solution of a Diophantine matrix equation by using of a Moore-Penrose pseudoinverse matrix. The method has been tested on several typical chemical equations and found to be very successful for the all equations in our extensive balancing research. This method, which works successfully without any limitations, also has the capability to determine the feasibility of a new chemical reaction, and if it is feasible, then it will balance the equation. Chemical equations treated here possess atoms with fractional oxidation numbers. Also, in the present work are introduced necessary and sufficient criteria for stability of chemical equations over stability of their extended matrices

A simple bacterial turbidimetric method for detection of some radurized foods

International Nuclear Information System (INIS)

Gautam, S.; Sharma, Arun; Thomas, Paul

1998-01-01

A simple and quick method for detection of irradiated food is proposed. The method is based on the principle of microbial contribution to the development of turbidity in a clear medium. It employs measurement of absorbance at 600 nm of the medium after the test commodity has been suspended and shaken in it for a fixed interval. The differences in the bacterial turbidity from irradiated and nonirradiated samples are quite marked so as to allow identification of the irradiated foods like fish, lamb meat, chicken and mushroom. (author)

Accurate and simple measurement method of complex decay schemes radionuclide activity

International Nuclear Information System (INIS)

Legrand, J.; Clement, C.; Bac, C.

1975-01-01

A simple method for the measurement of the activity is described. It consists of using a well-type sodium iodide crystal whose efficiency mith monoenergetic photon rays has been computed or measured. For each radionuclide with a complex decay scheme a total efficiency is computed; it is shown that the efficiency is very high, near 100%. The associated incertainty is low, in spite of the important uncertainties on the different parameters used in the computation. The method has been applied to the measurement of the 152 Eu primary reference [fr

A SIMPLE AND EFFECTIVE CURSIVE WORD SEGMENTATION METHOD

NARCIS (Netherlands)

nicchiotti, G.; Rimassa, S.; Scagliola, C.

2004-01-01

A simple procedure for cursive word oversegmentation is presented, which is based on the analysis of the handwritten profiles and on the extraction of ``white holes\\'\\'. It follows the policy of using simple rules on complex data and sophisticated rules on simpler data. Experimental results show

Safety in the Chemical Laboratory--Chemical Management: A Method for Waste Reduction.

Science.gov (United States)

Pine, Stanley H.

1984-01-01

Discusses methods for reducing or eliminating waste disposal problems in the chemistry laboratory, considering both economic and environmental aspects of the problems. Proposes inventory control, shared use, solvent recycling, zero effluent, and various means of disposing of chemicals. (JM)

Chemically reducing decontamination method for radioactive metal

International Nuclear Information System (INIS)

Tanaka, Akio; Onuma, Tsutomu; Sato, Hitoshi.

1994-01-01

The present invention concerns a decontamination method of electrolytically reducing radioactive metal wastes, then chemically dissolving the surface thereof with a strong acid decontaminating solution. This method utilizes dissolving characteristics of stainless steels in the strong acid solution. That is, in the electrolytic reduction operation, a portion of the metal wastes is brought into contact with a strong acid decontaminating solution, and voltage and current are applied to the portion and keep it for a long period of time so as to make the potential of the immersed portion of the metal wastes to an active soluble region. Then, the electrolytic reduction operation is stopped, and the metal wastes are entirely immersed in the decontaminating solution to decontaminate by chemical dissolution. As the decontaminating solution, strong acid such as sulfuric acid, nitric acid is used. Since DC current power source capacity required for causing reaction in the active soluble region can be decreased, the decontamination facility can be minimized and simplified, and necessary electric power can be saved even upon decontamination of radioactive metal wastes made of stainless steels and having a great area. Further, chemical dissolution can be conducted without adding an expensive oxidizing agent. (N.H.)

A Study of Simple α Source Preparation Using a Micro-coprecipitation Method

International Nuclear Information System (INIS)

Lee, Myung Ho; Park, Taehong; Song, Byung Chul; Park, Jong Ho; Song, Kyuseok

2012-01-01

This study presents a rapid and simple α source preparation method for a radioactive waste sample. The recovery of 239 Pu, 232 U and 243 Am using a micro-coprecipitation method was over 95%. The α-peak resolution of Pu and Am isotopes through the micro-coprecipitation method is enough to discriminate the Pu and Am isotopes from other Pu and Am isotopes. The determination of the Pu and Am isotopes using the micro-coprecipitation method was applied to the radioactive waste sample, so that the activity concentrations of the Pu and Am isotopes using the micro-coprecipitation method in the radioactive waste sample were similar to those using the electrodeposition method

Optimization of drilling mud conditioning for chemically enhanced centrifuging

Energy Technology Data Exchange (ETDEWEB)

Wojtanowicz, A. K. [Louisiana State Univ., Baton Rouge, LA (United States); Ye, Y. [Jianghan Petroleum Institute, Beijing, (China)

1998-05-01

A simple method (the nine point (9-P) experiment) for finding optimum chemical conditioning that would maximize mud volume reduction, (i.e. enhance water removal or dewatering) and minimize the cost of the chemicals required, was described. The 9-P experiment is based on the statistical theory of factorial analysis and derives its name from the fact that it requires only nine tests to find the optimum treatment. The experimental design and the method of analysis are described. When compared to conventional trial-and-error approaches, the 9-P method showed a 1.78 to 2.35-fold increase in volume reduction efficiency, and up to 3.7-fold reduction in chemical usage.

Chemical Mixtures Health Risk Assessment of Environmental Contaminants: Concepts, Methods, Applications

Science.gov (United States)

This problems-based, introductory workshop focuses on methods to assess health risks posed by exposures to chemical mixtures in the environment. Chemical mixtures health risk assessment methods continue to be developed and evolve to address concerns over health risks from multic...

New simple method for fast and accurate measurement of volumes

International Nuclear Information System (INIS)

Frattolillo, Antonio

2006-01-01

A new simple method is presented, which allows us to measure in just a few minutes but with reasonable accuracy (less than 1%) the volume confined inside a generic enclosure, regardless of the complexity of its shape. The technique proposed also allows us to measure the volume of any portion of a complex manifold, including, for instance, pipes and pipe fittings, valves, gauge heads, and so on, without disassembling the manifold at all. To this purpose an airtight variable volume is used, whose volume adjustment can be precisely measured; it has an overall capacity larger than that of the unknown volume. Such a variable volume is initially filled with a suitable test gas (for instance, air) at a known pressure, as carefully measured by means of a high precision capacitive gauge. By opening a valve, the test gas is allowed to expand into the previously evacuated unknown volume. A feedback control loop reacts to the resulting finite pressure drop, thus contracting the variable volume until the pressure exactly retrieves its initial value. The overall reduction of the variable volume achieved at the end of this process gives a direct measurement of the unknown volume, and definitively gets rid of the problem of dead spaces. The method proposed actually does not require the test gas to be rigorously held at a constant temperature, thus resulting in a huge simplification as compared to complex arrangements commonly used in metrology (gas expansion method), which can grant extremely accurate measurement but requires rather expensive equipments and results in time consuming methods, being therefore impractical in most applications. A simple theoretical analysis of the thermodynamic cycle and the results of experimental tests are described, which demonstrate that, in spite of its simplicity, the method provides a measurement accuracy within 0.5%. The system requires just a few minutes to complete a single measurement, and is ready immediately at the end of the process. The

A simple micro-photometric method for urinary iodine determination.

Science.gov (United States)

Grimm, Gabriele; Lindorfer, Heidelinde; Kieweg, Heidi; Marculescu, Rodrig; Hoffmann, Martha; Gessl, Alois; Sager, Manfred; Bieglmayer, Christian

2011-10-01

Urinary iodide concentration (UIC) is useful to evaluate nutritional iodine status. In clinical settings UIC helps to exclude blocking of the thyroid gland by excessive endogenous iodine, if diagnostic or therapeutic administration of radio-iodine is indicated. Therefore, this study established a simple test for the measurement of UIC. UIC was analyzed in urine samples of 200 patients. Samples were pre-treated at 95°C for 45 min with ammonium persulfate in a thermal cycler, followed by a photometric Sandell-Kolthoff reaction (SK) carried out in microtiter plates. For method comparison, UIC was analyzed in 30 samples by inductivity coupled plasma mass spectro-metry (ICP-MS) as a reference method. Incubation conditions were optimized concerning recovery. The photometric test correlated well to the reference method (SK=0.91*ICP-MS+1, r=0.962) and presented with a functional sensitivity of 20 μg/L. UIC of patient samples ranged from photometric test provides satisfactory results and can be performed with the basic equipment of a clinical laboratory.

QSAR modelling using combined simple competitive learning networks and RBF neural networks.

Science.gov (United States)

Sheikhpour, R; Sarram, M A; Rezaeian, M; Sheikhpour, E

2018-04-01

The aim of this study was to propose a QSAR modelling approach based on the combination of simple competitive learning (SCL) networks with radial basis function (RBF) neural networks for predicting the biological activity of chemical compounds. The proposed QSAR method consisted of two phases. In the first phase, an SCL network was applied to determine the centres of an RBF neural network. In the second phase, the RBF neural network was used to predict the biological activity of various phenols and Rho kinase (ROCK) inhibitors. The predictive ability of the proposed QSAR models was evaluated and compared with other QSAR models using external validation. The results of this study showed that the proposed QSAR modelling approach leads to better performances than other models in predicting the biological activity of chemical compounds. This indicated the efficiency of simple competitive learning networks in determining the centres of RBF neural networks.

Determination of chemical oxygen demand (COD) using an alternative wet chemical method free of mercury and dichromate.

Science.gov (United States)

Kolb, Marit; Bahadir, Müfit; Teichgräber, Burkhard

2017-10-01

Worldwide, the standard methods for the determination of the important wastewater parameter chemical oxygen demand (COD) are still based on the use of the hazardous chemicals, mercury sulfate and chromium(VI). However, due to their properties they are meanwhile classified as "priority pollutants" and shall be phased out or banned in the frame of REACH (current European Chemical Law: Registration, Evaluation, Authorization and restriction of Chemicals) by the European Union. Hence, a new wet-chemical method free of mercury and chromium(VI) was developed. Manganese(III) was used as oxidant and silver nitrate for the removal of chloride ions. The quantification was performed by back titration of manganese(III) with iron(II) as done in the standard method. In order to minimize losses of organic substances during the precipitation of silver chloride, suspended and colloid organic matter had to be separated by precipitation of aluminum hydroxide in a first step. In these cases, two fractions, one of the suspended and colloid matters and a second of the dissolved organic substances, are prepared and oxidized separately. The method was tested with potassium hydrogen phthalate (KHP) as conventional COD reference substance and different types of wastewater samples. The oxidation of KHP was reproducible in a COD range of 20-500 mg/L with a mean recovery rate of 88.7% in comparison to the standard COD method (DIN 38409-41). Also in presence of 1000 mg/L chloride a recovery rate of 84.1% was reached. For a series of industrial and municipal wastewater samples a high correlation (R 2  = 0.9935) to the standard method with a mean recovery rate of 78.1% (±5.2%) was determined. Even though the results of the new method are not 100% of the standard method, its high correlation to the standard method and reproducibility offers an environmentally benign alternative method with no need to purchase new laboratory equipment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Accurate and simple method for quantification of hepatic fat content using magnetic resonance imaging: a prospective study in biopsy-proven nonalcoholic fatty liver disease.

Science.gov (United States)

Hatta, Tomoko; Fujinaga, Yasunari; Kadoya, Masumi; Ueda, Hitoshi; Murayama, Hiroaki; Kurozumi, Masahiro; Ueda, Kazuhiko; Komatsu, Michiharu; Nagaya, Tadanobu; Joshita, Satoru; Kodama, Ryo; Tanaka, Eiji; Uehara, Tsuyoshi; Sano, Kenji; Tanaka, Naoki

2010-12-01

To assess the degree of hepatic fat content, simple and noninvasive methods with high objectivity and reproducibility are required. Magnetic resonance imaging (MRI) is one such candidate, although its accuracy remains unclear. We aimed to validate an MRI method for quantifying hepatic fat content by calibrating MRI reading with a phantom and comparing MRI measurements in human subjects with estimates of liver fat content in liver biopsy specimens. The MRI method was performed by a combination of MRI calibration using a phantom and double-echo chemical shift gradient-echo sequence (double-echo fast low-angle shot sequence) that has been widely used on a 1.5-T scanner. Liver fat content in patients with nonalcoholic fatty liver disease (NAFLD, n = 26) was derived from a calibration curve generated by scanning the phantom. Liver fat was also estimated by optical image analysis. The correlation between the MRI measurements and liver histology findings was examined prospectively. Magnetic resonance imaging measurements showed a strong correlation with liver fat content estimated from the results of light microscopic examination (correlation coefficient 0.91, P hepatic steatosis. Moreover, the severity of lobular inflammation or fibrosis did not influence the MRI measurements. This MRI method is simple and noninvasive, has excellent ability to quantify hepatic fat content even in NAFLD patients with mild steatosis or advanced fibrosis, and can be performed easily without special devices.

A simple and rapid method of purification of impure plutonium oxide

International Nuclear Information System (INIS)

Michael, K.M.; Rakshe, P.R.; Dharmpurikar, G.R.; Thite, B.S.; Lokhande, Manisha; Sinalkar, Nitin; Dakshinamoorthy, A.; Munshi, S.K.; Dey, P.K.

2007-01-01

Impure plutonium oxides are conventionally purified by dissolution in HNO 3 in presence of HF followed by ion exchange separation and oxalate precipitation. The method is tedious and use of HF enhances corrosion of the plant equipment's. A simple and rapid method has been developed for the purification of the oxide by leaching with various reagents like DM water, NaOH and oxalic acid. A combination of DM water followed by hot leaching with 0.4 M oxalic acid could bring down the impurity levels in the oxide to the desired level required for fuel fabrication. (author)

A simple method for percutaneous resection of osteoid osteoma

International Nuclear Information System (INIS)

Kamrani, Reza S.; Kiani, K.; Mazlouman, Shahriar J.

2007-01-01

To introduce a method that can be performed with minimal equipments available to most orthopedic surgeons and precludes the extensive anesthetic and ablative requirements. A percutaneous lead tunnel was first established in the cortex next to the nidus under computerized tomography guidance with local anesthesia; then the nidus was curetted in the operating room through the lead tunnel. The study was performed in Shariati Hospital in Tehran, Iran, from September 2002 to December 2005. Nineteen patients were treated with this method with 94.7% cure rate. The diagnosis was histologically confirmed in 16 cases (84.2%). Failure occurred in one patient. The patients had a mean follow-up of 13.5 months with no recurrence of symptoms with mean hospitalization time of 1.6 days. This technique is simple, minimally invasive and effective. It needs no especial equipments and provides the material for tissue diagnosis. (author)

Optical properties of silver sulphide thin films formed on evaporated Ag by a simple sulphurization method

Energy Technology Data Exchange (ETDEWEB)

Barrera-Calva, E., E-mail: ebc@xanum.uam.m [Departamento de Ingenieria de Procesos e hidraulica, Universidad Autonoma Metropolitana - Iztapalapa, Av. Purisima Esq. Michoacan, Col. Vicentina, Mexico, D.F., 09340 (Mexico); Ortega-Lopez, M.; Avila-Garcia, A.; Matsumoto-Kwabara, Y. [Departamento de Ingenieria Electrica, Centro de Investigacion y de Estudios Avanzados del IPN, Mexico DF 07360 (Mexico)

2010-01-31

Silver sulphide (Ag{sub 2}S) thin films were grown on the surface of silver films (Ag) deposited on glass substrate by using a simple chemical sulphurization method. According to X-ray diffraction analysis, the Ag{sub 2}S thin films display low intensity peaks at 34.48{sup o}, 36.56{sup o}, and 44.28{sup o}, corresponding to diffraction from (100), (112) and (103) planes of the acanthite phase (monoclinic). A model of the type Ag{sub 2}S/Ag/glass was deduced from spectroscopic ellipsometric measurements. Also, the optical constants (n, k) of the system were determined. Furthermore, the optical properties as solar selective absorber for collector applications were assessed. The optical reflectance of the Ag{sub 2}S/Ag thin film systems exhibits the expected behavior for an ideal selective absorber, showing a low reflectance in the wavelength range below 2 {mu}m and a high reflectance for wavelengths higher than that value. An absorptance about 70% and an emittance about 3% or less were calculated for several samples.

Manual of selected physico-chemical analytical methods. IV

International Nuclear Information System (INIS)

Beran, M.; Klosova, E.; Krtil, J.; Sus, F.; Kuvik, V.; Vrbova, L.; Hamplova, M.; Lengyel, J.; Kelnar, L.; Zakouril, K.

1990-11-01

The Central Testing Laboratory of the Nuclear Research Institute at Rez has for a decade been participating in the development of analytical procedures and has been providing analyses of samples of different types and origin. The analytical procedures developed have been published in special journals and a number of them in the Manuals of analytical methods, in three parts. The 4th part of the Manual contains selected physico-chemical methods developed or modified by the Laboratory in the years 1986-1990 within the project ''Development of physico-chemical analytical methods''. In most cases, techniques are involved for non-nuclear applications. Some can find wider applications, especially in analyses of environmental samples. Others have been developed for specific cases of sample analyses or require special instrumentation (mass spectrometer), which partly restricts their applicability by other institutions. (author)

A simple scintigraphic method for continuous monitoring of gastric emptying

Energy Technology Data Exchange (ETDEWEB)

Lipp, R.W.; Hammer, H.F.; Schnedl, W.; Dobnig, H.; Passath, A.; Leb, G.; Krejs, G.J. (Graz Univ. (Austria). Div. of Nuclear Medicine and Endocrinology)

1993-03-01

A new and simple scintigraphic method for the measurement of gastric emptying was developed and validated. The test meal consists of 200 g potato mash mixed with 0.5 g Dowex 2X8 particles (mesh 20-50) labelled with 37 MBq (1 mCi) technetium-99m. After ingestion of the meal, sequential dynamic 15-s anteroposterior exposures in the supine position are obtained for 90 min. A second recording sequence of 20 min is added after a 30-min interval. The results can be displayed as immediate cine-replay, as time-activity diagrams and/or as acitivty retention values. Complicated mathematical fittings are not necessary. The method lends itself equally to the testing of in- and outpatients. (orig.).

Facile fabrication of CNT-based chemical sensor operating at room temperature

Science.gov (United States)

Sheng, Jiadong; Zeng, Xian; Zhu, Qi; Yang, Zhaohui; Zhang, Xiaohua

2017-12-01

This paper describes a simple, low cost and effective route to fabricate CNT-based chemical sensors, which operate at room temperature. Firstly, the incorporation of silk fibroin in vertically aligned CNT arrays (CNTA) obtained through a thermal chemical vapor deposition (CVD) method makes the direct removal of CNT arrays from substrates without any rigorous acid or sonication treatment feasible. Through a simple one-step in situ polymerization of anilines, the functionalization of CNT arrays with polyaniline (PANI) significantly improves the sensing performance of CNT-based chemical sensors in detecting ammonia (NH3) and hydrogen chloride (HCl) vapors. Chemically modified CNT arrays also show responses to organic vapors like menthol, ethyl acetate and acetone. Although the detection limits of chemically modified CNT-based chemical sensors are of the same orders of magnitudes reported in previous studies, these CNT-based chemical sensors show advantages of simplicity, low cost and energy efficiency in preparation and fabrication of devices. Additionally, a linear relationship between the relative sensitivity and concentration of analyte makes precise estimations on the concentrations of trace chemical vapors possible.

Insights: A New Method to Balance Chemical Equations.

Science.gov (United States)

Garcia, Arcesio

1987-01-01

Describes a method designed to balance oxidation-reduction chemical equations. Outlines a method which is based on changes in the oxidation number that can be applied to both molecular reactions and ionic reactions. Provides examples and delineates the steps to follow for each type of equation balancing. (TW)

A simple optical method for measuring the vibration amplitude of a speaker

OpenAIRE

UEDA, Masahiro; YAMAGUCHI, Toshihiko; KAKIUCHI, Hiroki; SUGA, Hiroshi

1999-01-01

A simple optical method has been proposed for measuring the vibration amplitude of a speaker vibrating with a frequency of approximately 10 kHz. The method is based on a multiple reflection between a vibrating speaker plane and a mirror parallel to that speaker plane. The multiple reflection can magnify a dispersion of the laser beam caused by the vibration, and easily make a measurement of the amplitude. The measuring sensitivity ranges between sub-microns and 1 mm. A preliminary experim...

A simple method to downscale daily wind statistics to hourly wind data

OpenAIRE

Guo, Zhongling

2013-01-01

Wind is the principal driver in the wind erosion models. The hourly wind speed data were generally required for precisely wind erosion modeling. In this study, a simple method to generate hourly wind speed data from daily wind statistics (daily average and maximum wind speeds together or daily average wind speed only) was established. A typical windy location with 3285 days (9 years) measured hourly wind speed data were used to validate the downscaling method. The results showed that the over...

Simulation Opportunity Index, A Simple and Effective Method to Boost the Hydrocarbon Recovery

KAUST Repository

Saputra, Wardana

2016-01-01

This paper describes how the SOI software helps as a simple, fast, and accurate way to obtain the higher hydrocarbon production than that of trial-error method and previous studies in two different fields located in offshore Indonesia. On one hand, the proposed method could save money by minimizing the required number of wells. On the other hand, it could maximize profit by maximizing recovery.

Novel and simple route to fabricate fully biocompatible plasmonic mushroom arrays adhered on silk biopolymer

Science.gov (United States)

Park, Joonhan; Choi, Yunkyoung; Lee, Myungjae; Jeon, Heonsu; Kim, Sunghwan

2014-12-01

A fully biocompatible plasmonic quasi-3D nanostructure is demonstrated by a simple and reliable fabrication method using strong adhesion between gold and silk fibroin. The quasi-3D nature gives rise to complex photonic responses in reflectance that are prospectively useful in bio/chemical sensing applications. Laser interference lithography is utilized to fabricate large-area plasmonic nanostructures.A fully biocompatible plasmonic quasi-3D nanostructure is demonstrated by a simple and reliable fabrication method using strong adhesion between gold and silk fibroin. The quasi-3D nature gives rise to complex photonic responses in reflectance that are prospectively useful in bio/chemical sensing applications. Laser interference lithography is utilized to fabricate large-area plasmonic nanostructures. Electronic supplementary information (ESI) available: The incident angle dependence of reflectance spectra and the atomic force microscopy image of the Au nanoparticle array on a silk film after 1 hour of ultrasonication. See DOI: 10.1039/c4nr05172f

Simple growth patterns can create complex trajectories for the ontogeny of constitutive chemical defences in seaweeds.

Directory of Open Access Journals (Sweden)

Nicholas A Paul

Full Text Available All of the theory and most of the data on the ecology and evolution of chemical defences derive from terrestrial plants, which have considerable capacity for internal movement of resources. In contrast, most macroalgae--seaweeds--have no or very limited capacity for resource translocation, meaning that trade-offs between growth and defence, for example, should be localised rather than systemic. This may change the predictions of chemical defence theories for seaweeds. We developed a model that mimicked the simple growth pattern of the red seaweed Asparagopsis armata which is composed of repeating clusters of somatic cells and cells which contain deterrent secondary chemicals (gland cells. To do this we created a distinct growth curve for the somatic cells and another for the gland cells using empirical data. The somatic growth function was linked to the growth function for defence via differential equations modelling, which effectively generated a trade-off between growth and defence as these neighbouring cells develop. By treating growth and defence as separate functions we were also able to model a trade-off in growth of 2-3% under most circumstances. However, we found contrasting evidence for this trade-off in the empirical relationships between growth and defence, depending on the light level under which the alga was cultured. After developing a model that incorporated both branching and cell division rates, we formally demonstrated that positive correlations between growth and defence are predicted in many circumstances and also that allocation costs, if they exist, will be constrained by the intrinsic growth patterns of the seaweed. Growth patterns could therefore explain contrasting evidence for cost of constitutive chemical defence in many studies, highlighting the need to consider the fundamental biology and ontogeny of organisms when assessing the allocation theories for defence.

Chemical analysis of cyanide in cyanidation process: review of methods

International Nuclear Information System (INIS)

Nova-Alonso, F.; Elorza-Rodriguez, E.; Uribe-Salas, A.; Perez-Garibay, R.

2007-01-01

Cyanidation, the world wide method for precious metals recovery, the chemical analysis of cyanide, is a very important, but complex operation. Cyanide can be present forming different species, each of them with different stability, toxicity, analysis method and elimination technique. For cyanide analysis, there exists a wide selection of analytical methods but most of them present difficulties because of the interference of species present in the solution. This paper presents the different available methods for chemical analysis of cyanide: titration, specific electrode and distillation, giving special emphasis on the interferences problem, with the aim of helping in the interpretation of the results. (Author)

Wrist arthrography: a simple method

Energy Technology Data Exchange (ETDEWEB)

Berna-Serna, Juan D.; Reus, Manuel; Alonso, Jose [Virgen de la Arrixaca University Hospital, Department of Radiology, El Palmar (Murcia) (Spain); Martinez, Francisco; Domenech-Ratto, Gines [University of Murcia, Department of Human Anatomy, Faculty of Medicine, Murcia (Spain)

2006-02-01

A technique of wrist arthrography is presented using an adhesive marker-plate with radiopaque coordinates to identify precisely sites for puncture arthrography of the wrist and to obviate the need for fluoroscopic guidance. Radiocarpal joint arthrography was performed successfully in all 24 cases, 14 in the cadaveric wrists and 10 in the live patients. The arthrographic procedure described in this study is simple, safe, and rapid, and has the advantage of precise localisation of the site for puncture without need for fluoroscopic guidance. (orig.)

Filtration Isolation of Nucleic Acids: A Simple and Rapid DNA Extraction Method.

Science.gov (United States)

McFall, Sally M; Neto, Mário F; Reed, Jennifer L; Wagner, Robin L

2016-08-06

FINA, filtration isolation of nucleic acids, is a novel extraction method which utilizes vertical filtration via a separation membrane and absorbent pad to extract cellular DNA from whole blood in less than 2 min. The blood specimen is treated with detergent, mixed briefly and applied by pipet to the separation membrane. The lysate wicks into the blotting pad due to capillary action, capturing the genomic DNA on the surface of the separation membrane. The extracted DNA is retained on the membrane during a simple wash step wherein PCR inhibitors are wicked into the absorbent blotting pad. The membrane containing the entrapped DNA is then added to the PCR reaction without further purification. This simple method does not require laboratory equipment and can be easily implemented with inexpensive laboratory supplies. Here we describe a protocol for highly sensitive detection and quantitation of HIV-1 proviral DNA from 100 µl whole blood as a model for early infant diagnosis of HIV that could readily be adapted to other genetic targets.

Minimizing the Free Energy: A Computer Method for Teaching Chemical Equilibrium Concepts.

Science.gov (United States)

Heald, Emerson F.

1978-01-01

Presents a computer method for teaching chemical equilibrium concepts using material balance conditions and the minimization of the free energy. Method for the calculation of chemical equilibrium, the computer program used to solve equilibrium problems and applications of the method are also included. (HM)

Sensitive and simple method for measuring wire tensions

International Nuclear Information System (INIS)

Atac, M.; Mishina, M.

1982-08-01

Measuring tension of wires in drift chambers and multiwire proportional chambers after construction is an important process because sometimes wires get loose after soldering, crimping or glueing. One needs to sort out wires which have tensions below a required minimum value to prevent electrostatic instabilities. There have been several methods reported on this subject in which the wires were excited either with sinusoidal current under magnetic field or with sinusoidal voltage electrostatically coupled to the wire, searching for a resonating frequency with which the wires vibrate mechanically. Then the vibration is detected either visually, optically or with magnetic pick-up directly touching the wires. Any of these is only applicable to the usual multiwire chamber which has open access to the wire plane. They also need fairly large excitation currents to induce a detectable vibration to the wires. Here we report a very simple method that can be used for any type of wire chamber or proportional tube system for measuring wire tension. Only a very small current is required for the wire excitation to obtain a large enough signal because it detects the induced emf voltage across a wire. A sine-wave oscillator and a digital voltmeter are sufficient devices aside from a permanent magnet to provide the magnetic field around the wire. A useful application of this method to a large system is suggested

Water-assisted growth of graphene on carbon nanotubes by the chemical vapor deposition method.

Science.gov (United States)

Feng, Jian-Min; Dai, Ye-Jing

2013-05-21

Combining carbon nanotubes (CNTs) with graphene has been proved to be a feasible method for improving the performance of graphene for some practical applications. This paper reports a water-assisted route to grow graphene on CNTs from ferrocene and thiophene dissolved in ethanol by the chemical vapor deposition method in an argon flow. A double injection technique was used to separately inject ethanol solution and water for the preparation of graphene/CNTs. First, CNTs were prepared from ethanol solution and water. The injection of ethanol solution was suspended and water alone was injected into the reactor to etch the CNTs. Thereafter, ethanol solution was injected along with water, which is the key factor in obtaining graphene/CNTs. Transmission electron microscopy, scanning electron microscopy, X-ray diffraction, and Raman scattering analyses confirmed that the products were the hybrid materials of graphene/CNTs. X-ray photo-electron spectroscopy analysis showed the presence of oxygen rich functional groups on the surface of the graphene/CNTs. Given the activity of the graphene/CNT surface, CdS quantum dots adhered onto it uniformly through simple mechanical mixing.

A simple method to approximate liver size on cross-sectional images using living liver models

International Nuclear Information System (INIS)

Muggli, D.; Mueller, M.A.; Karlo, C.; Fornaro, J.; Marincek, B.; Frauenfelder, T.

2009-01-01

Aim: To assess whether a simple. diameter-based formula applicable to cross-sectional images can be used to calculate the total liver volume. Materials and methods: On 119 cross-sectional examinations (62 computed tomography and 57 magnetic resonance imaging) a simple, formula-based method to approximate the liver volume was evaluated. The total liver volume was approximated measuring the largest craniocaudal (cc), ventrodorsal (vd), and coronal (cor) diameters by two readers and implementing the equation: Vol estimated =ccxvdxcorx0.31. Inter-rater reliability, agreement, and correlation between liver volume calculation and virtual liver volumetry were analysed. Results: No significant disagreement between the two readers was found. The formula correlated significantly with the volumetric data (r > 0.85, p < 0.0001). In 81% of cases the error of the approximated volume was <10% and in 92% of cases <15% compared to the volumetric data. Conclusion: Total liver volume can be accurately estimated on cross-sectional images using a simple, diameter-based equation.

Simple and efficient methods for the accurate evaluation of patterning effects in ultrafast photonic switches

DEFF Research Database (Denmark)

Xu, Jing; Ding, Yunhong; Peucheret, Christophe

2011-01-01

Although patterning effects (PEs) are known to be a limiting factor of ultrafast photonic switches based on semiconductor optical amplifiers (SOAs), a simple approach for their evaluation in numerical simulations and experiments is missing. In this work, we experimentally investigate and verify...... as well as the operation bit rate. Furthermore, a simple and effective method for probing the maximum PEs is demonstrated, which may relieve the computational effort or the experimental difficulties associated with the use of long PRBSs for the simulation or characterization of SOA-based switches. Good...... agrement with conventional PRBS characterization is obtained. The method is suitable for quick and systematic estimation and optimization of the switching performance....

Note on a simple test method for estimaing J/sub Ic/

International Nuclear Information System (INIS)

Whipple, T.A.; McHenry, H.I.

1980-01-01

Fracture toughness testing is generally a time-consuming and expensive procedure; therefore, there has been a significant amount of effort directed toward developing an inexpensive and rapid method of estimating the fracture toughness of materials. In this paper, a simple method for estimating J/sub Ic/ through the use of small, notched, bend bars is evaluated. The test only involves the measurement of the energy necessary to fracture the sample. Initial tests on Fe-18Cr-3Ni-13Mn and 304L stainless steel at 76 and 4 0 K have yielded results consistent with other fracture toughness tests, for materials in the low- to medium-toughness range

Complexity is simple!

Science.gov (United States)

Cottrell, William; Montero, Miguel

2018-02-01

In this note we investigate the role of Lloyd's computational bound in holographic complexity. Our goal is to translate the assumptions behind Lloyd's proof into the bulk language. In particular, we discuss the distinction between orthogonalizing and `simple' gates and argue that these notions are useful for diagnosing holographic complexity. We show that large black holes constructed from series circuits necessarily employ simple gates, and thus do not satisfy Lloyd's assumptions. We also estimate the degree of parallel processing required in this case for elementary gates to orthogonalize. Finally, we show that for small black holes at fixed chemical potential, the orthogonalization condition is satisfied near the phase transition, supporting a possible argument for the Weak Gravity Conjecture first advocated in [1].

The calculation of proton chemical shifts in hydrocarbons

Energy Technology Data Exchange (ETDEWEB)

Abraham, Raymond J [Liverpool Univ. (United Kingdom). Dept. of Chemistry

1994-12-31

Novel extension of the CHARGE3 semi-empirical calculation of the partial atomic charges in molecules are described which allow the accurate calculation of the proton chemical shifts of a variety of acyclic alkanes. This simple scheme predicts the proton chemical shifts of all the simple alkanes, cyclohexane and methyl cyclohexanes, norbornane, trans-decalin and trans perhydrophenanthrene, comprising a range of chemical shifts from 0.3 to 2.2 {delta} with the known substituent chemical shifts of other functional groups this could allow the general prediction of proton chemical shifts in a simple and useful format. (author) 13 refs., 2 figs.

Machine learning plus optical flow: a simple and sensitive method to detect cardioactive drugs

Science.gov (United States)

Lee, Eugene K.; Kurokawa, Yosuke K.; Tu, Robin; George, Steven C.; Khine, Michelle

2015-07-01

Current preclinical screening methods do not adequately detect cardiotoxicity. Using human induced pluripotent stem cell-derived cardiomyocytes (iPS-CMs), more physiologically relevant preclinical or patient-specific screening to detect potential cardiotoxic effects of drug candidates may be possible. However, one of the persistent challenges for developing a high-throughput drug screening platform using iPS-CMs is the need to develop a simple and reliable method to measure key electrophysiological and contractile parameters. To address this need, we have developed a platform that combines machine learning paired with brightfield optical flow as a simple and robust tool that can automate the detection of cardiomyocyte drug effects. Using three cardioactive drugs of different mechanisms, including those with primarily electrophysiological effects, we demonstrate the general applicability of this screening method to detect subtle changes in cardiomyocyte contraction. Requiring only brightfield images of cardiomyocyte contractions, we detect changes in cardiomyocyte contraction comparable to - and even superior to - fluorescence readouts. This automated method serves as a widely applicable screening tool to characterize the effects of drugs on cardiomyocyte function.

Development of the simple evaluation method of the soil biomass by the ATP measurement

Czech Academy of Sciences Publication Activity Database

Urashima, Y.; Nakajima, M.; Kaneda, Satoshi; Murakami, T.

2007-01-01

Roč. 78, č. 2 (2007), s. 187-190 ISSN 0029-0610 Institutional research plan: CEZ:AV0Z60660521 Keywords : simple evaluation method * soil biomass * ATP measurement Subject RIV: EH - Ecology, Behaviour

ZnS nanoflakes deposition by modified chemical method

International Nuclear Information System (INIS)

Desai, Mangesh A.; Sartale, S. D.

2014-01-01

We report deposition of zinc sulfide nanoflakes on glass substrates by modified chemical method. The modified chemical method involves adsorption of zinc–thiourea complex on the substrate and its dissociation in presence of hydroxide ions to release sulfur ions from thiourea which react with zinc ions present in the complex to form zinc sulfide nanoflakes at room temperature. Influence of zinc salt and thiourea concentrations ratios on the morphology of the films was investigated by scanning electron microscope (SEM). The ratio of zinc and thiourea in the zinc–thiourea complex significantly affect the size of the zinc sulfide nanoflakes, especially width and density of the nanoflakes. The X-ray diffraction analysis exhibits polycrystalline nature of the zinc sulfide nanoflakes with hexagonal phase

Approximate method for stochastic chemical kinetics with two-time scales by chemical Langevin equations

International Nuclear Information System (INIS)

Wu, Fuke; Tian, Tianhai; Rawlings, James B.; Yin, George

2016-01-01

The frequently used reduction technique is based on the chemical master equation for stochastic chemical kinetics with two-time scales, which yields the modified stochastic simulation algorithm (SSA). For the chemical reaction processes involving a large number of molecular species and reactions, the collection of slow reactions may still include a large number of molecular species and reactions. Consequently, the SSA is still computationally expensive. Because the chemical Langevin equations (CLEs) can effectively work for a large number of molecular species and reactions, this paper develops a reduction method based on the CLE by the stochastic averaging principle developed in the work of Khasminskii and Yin [SIAM J. Appl. Math. 56, 1766–1793 (1996); ibid. 56, 1794–1819 (1996)] to average out the fast-reacting variables. This reduction method leads to a limit averaging system, which is an approximation of the slow reactions. Because in the stochastic chemical kinetics, the CLE is seen as the approximation of the SSA, the limit averaging system can be treated as the approximation of the slow reactions. As an application, we examine the reduction of computation complexity for the gene regulatory networks with two-time scales driven by intrinsic noise. For linear and nonlinear protein production functions, the simulations show that the sample average (expectation) of the limit averaging system is close to that of the slow-reaction process based on the SSA. It demonstrates that the limit averaging system is an efficient approximation of the slow-reaction process in the sense of the weak convergence.

Chemical decontamination method for radioactive metal waste

International Nuclear Information System (INIS)

Tanaka, Akio; Onuma, Tsutomu; Yamazaki, Sei; Miura, Haruki.

1993-01-01

The present invention provides a chemical decontamination method for radioactive metal wastes, which are generated from radioactive material handling facilities and the surfaces of which are contaminated by radioactive materials. That is, it has a feature of applying acid dissolution simultaneously with mechanical grinding. The radioactive metal wastes are contained in a vessel such as a barrel together with abrasives in a sulfuric acid solution and rotated at several tens rotation per minute. By such procedures for the radioactive metal wastes, (1) cruds and passive membranes are mechanically removed, (2) exposed mother metal materials are uniformly brought into contact with sulfuric acid and further (3) the mother metal materials dissolve the cruds and the passive membranes also chemically by a reducing dissolution (so-called local cell effect). According to the method of the present invention, stainless steel metal wastes having cruds and passive membranes can rapidly and efficiently be decontaminated to a radiation level equal with that of ordinary wastes. (I.S.)

In silico toxicology: computational methods for the prediction of chemical toxicity

KAUST Repository

Raies, Arwa B.; Bajic, Vladimir B.

2016-01-01

Determining the toxicity of chemicals is necessary to identify their harmful effects on humans, animals, plants, or the environment. It is also one of the main steps in drug design. Animal models have been used for a long time for toxicity testing. However, in vivo animal tests are constrained by time, ethical considerations, and financial burden. Therefore, computational methods for estimating the toxicity of chemicals are considered useful. In silico toxicology is one type of toxicity assessment that uses computational methods to analyze, simulate, visualize, or predict the toxicity of chemicals. In silico toxicology aims to complement existing toxicity tests to predict toxicity, prioritize chemicals, guide toxicity tests, and minimize late-stage failures in drugs design. There are various methods for generating models to predict toxicity endpoints. We provide a comprehensive overview, explain, and compare the strengths and weaknesses of the existing modeling methods and algorithms for toxicity prediction with a particular (but not exclusive) emphasis on computational tools that can implement these methods and refer to expert systems that deploy the prediction models. Finally, we briefly review a number of new research directions in in silico toxicology and provide recommendations for designing in silico models.

In silico toxicology: computational methods for the prediction of chemical toxicity

KAUST Repository

Raies, Arwa B.

2016-01-06

Determining the toxicity of chemicals is necessary to identify their harmful effects on humans, animals, plants, or the environment. It is also one of the main steps in drug design. Animal models have been used for a long time for toxicity testing. However, in vivo animal tests are constrained by time, ethical considerations, and financial burden. Therefore, computational methods for estimating the toxicity of chemicals are considered useful. In silico toxicology is one type of toxicity assessment that uses computational methods to analyze, simulate, visualize, or predict the toxicity of chemicals. In silico toxicology aims to complement existing toxicity tests to predict toxicity, prioritize chemicals, guide toxicity tests, and minimize late-stage failures in drugs design. There are various methods for generating models to predict toxicity endpoints. We provide a comprehensive overview, explain, and compare the strengths and weaknesses of the existing modeling methods and algorithms for toxicity prediction with a particular (but not exclusive) emphasis on computational tools that can implement these methods and refer to expert systems that deploy the prediction models. Finally, we briefly review a number of new research directions in in silico toxicology and provide recommendations for designing in silico models.

A simple and inexpensive method for genomic restriction mapping analysis

International Nuclear Information System (INIS)

Huang, C.H.; Lam, V.M.S.; Tam, J.W.O.

1988-01-01

The Southern blotting procedure for the transfer of DNA fragments from agarose gels to nitrocellulose membranes has revolutionized nucleic acid detection methods, and it forms the cornerstone of research in molecular biology. Basically, the method involves the denaturation of DNA fragments that have been separated on an agarose gel, the immobilization of the fragments by transfer to a nitrocellulose membrane, and the identification of the fragments of interest through hybridization to /sup 32/P-labeled probes and autoradiography. While the method is sensitive and applicable to both genomic and cloned DNA, it suffers from the disadvantages of being time consuming and expensive, and fragments of greater than 15 kb are difficult to transfer. Moreover, although theoretically the nitrocellulose membrane can be washed and hybridized repeatedly using different probes, in practice, the membrane becomes brittle and difficult to handle after a few cycles. A direct hybridization method for pure DNA clones was developed in 1975 but has not been widely exploited. The authors report here a modification of their procedure as applied to genomic DNA. The method is simple, rapid, and inexpensive, and it does not involve transfer to nitrocellulose membranes

A Simple Method for Measuring the Verticality of Small-Diameter Driven Wells

DEFF Research Database (Denmark)

Kjeldsen, Peter; Skov, Bent

1994-01-01

The presence of stones, solid waste, and other obstructions can deflect small-diameter driven wells during installation, leading to deviations of the well from its intended position. This could lead to erroneous results, especially for measurements of ground water levels by water level meters....... A simple method was developed to measure deviations from the intended positions of well screens and determine correction factors required for proper measurement of ground water levels in nonvertical wells. The method is based upon measurement of the hydrostatic pressure in the bottom of a water column...... ground water flow directions....

A Nonmonotone Trust Region Method for Nonlinear Programming with Simple Bound Constraints

International Nuclear Information System (INIS)

Chen, Z.-W.; Han, J.-Y.; Xu, D.-C.

2001-01-01

In this paper we propose a nonmonotone trust region algorithm for optimization with simple bound constraints. Under mild conditions, we prove the global convergence of the algorithm. For the monotone case it is also proved that the correct active set can be identified in a finite number of iterations if the strict complementarity slackness condition holds, and so the proposed algorithm reduces finally to an unconstrained minimization method in a finite number of iterations, allowing a fast asymptotic rate of convergence. Numerical experiments show that the method is efficient

Toxicity assessment of chemical contaminants;transition from in vitromethods to novel in vitro methods

Directory of Open Access Journals (Sweden)

A.A. Farshad

2007-04-01

Full Text Available Exposure to occupational and environmental contaminants is a major contributor to human health problems. Despite significant achievements in the risk assessment of chemicals, the toxicological database, particularly for industrial chemicals, remains limited. Considering there areapproximately 80, 000 chemicals in commerce, and an extremely large number of chemical mixtures, in vivo testing of this large number is unachievable from ethical, economical and scientific perspectives. Therefore, increasing the number of available industrial chemicals andnew products has created a demand for alternatives to animal methods for better safety evaluation. Recent toxicity studies have demonstrated that in vitro methods are capable of rapidly providing toxicity information. In this review, current toxicity test methods for risk evaluation of industrial chemical contaminants are presented. To evaluate the potential applications of  more recent test methods developed for toxicity testing of chemical contaminants are discussed. Although  to be considered more broadly for risk assessment of human chemical exposures. In vitro methods,in vitro toxicology methods cannot exactly mimic the biodynamics of the whole body, in vitro  relationships (QSARs and physiologically based toxicokinetic (PBTK models have a potentialtest systems in combination with the knowledge of quantitative structure activity.

Method for fractional solid-waste sampling and chemical analysis

DEFF Research Database (Denmark)

Riber, Christian; Rodushkin, I.; Spliid, Henrik

2007-01-01

four subsampling methods and five digestion methods, paying attention to the heterogeneity and the material characteristics of the waste fractions, it was possible to determine 61 substances with low detection limits, reasonable variance, and high accuracy. For most of the substances of environmental...... of variance (20-85% of the overall variation). Only by increasing the sample size significantly can this variance be reduced. The accuracy and short-term reproducibility of the chemical characterization were good, as determined by the analysis of several relevant certified reference materials. Typically, six...... to eight different certified reference materials representing a range of concentrations levels and matrix characteristics were included. Based on the documentation provided, the methods introduced were considered satisfactory for characterization of the chemical composition of waste-material fractions...

New methods of sup(111)In chemical separation

International Nuclear Information System (INIS)

Santos, D.F.; Osso Junior, J.A.; Bastos, M.A.V.; Britto, J.L.Q.; Silva, R.F.

1986-01-01

The cation exchange and thermochromatography methods for chemical separation of sup(111) In from silver targets are described. The cation exchange method is based on the difference between In and Ag distribution coefficients on cation exchange resin treated with HNO sub(3). The thermochromatography consists of indium diffusion on silver melted after sublimation and posterior condensation. (M.C.K.)

Investigation of Chemical Equilibrium Kinetics by the Electromigration Method

CERN Document Server

Bozhikov, G A; Bontchev, G D; Maslov, O D; Milanov, M V; Dmitriev, S N

2002-01-01

Measurement of the chemical reaction rates for complex formation as well as hydrolysis type reactions by the method of horizontal zone electrophoresis is outlined. The correlation between chemical equilibrium kinetics and electrodiffusion processes in a constant d.c. electric field is described. In model electromigration experiments the reaction rate constant of the complex formation of Hf(IV) and DTPA is determined.

Chemical Mixtures Health Risk Assessment of Environmental Contaminants: Concepts, Methods, And Applications

Science.gov (United States)

This problems-based, introductory workshop focuses on methods to assess health risks posed by exposures to chemical mixtures in the environment. Chemical mixtures health risk assessment methods continue to be developed and evolve to address concerns over health risks from multic...

A new and simple gravimetric method for determination of uranium

International Nuclear Information System (INIS)

Saxena, A.K.

1994-01-01

A new and simple gravimetric method for determining uranium has been described. Using a known quantity of uranyl nitrate as the test solution, an alcoholic solution of 2-amino-2-methyl 1:3 propanediol (AMP) was added slowly. A yellow precipitate was obtained which was filtered through ashless filter paper, washed with alcohol, dried and ignited at 800 degC for 4h. It gave a black powder as a product which was shown by X-ray diffraction to be U 3 O 8 . The percentage error was found in the range -0.09 to +0.89. (author). 8 refs., 1 tab

A simple and rapid method for the determination of iodine in rice samples by radiochemical neutron activation analysis

International Nuclear Information System (INIS)

Takagi, Hiroyuki; Kimura, Toshimasa; Iwashima, Kiyoshi; Yamagata, Noboru.

1983-01-01

A simple and rapid method has been developed for the determination of iodine in rice samples by radiochemical neutron activation analysis. Irradiated rice powder was decomposed together with an iodide carrier solution containing I-131 on heating in a sodium hypochlorite solution. After decomposition, the solution was acidified with hydrochloric acid, and the insoluble residue was filtered off. To the filtrate sodium sulfite solution and palladium chloride solution were added, and the precipitate of palladium iodide was separated with a glass fiber filter paper. Iodine contents of rice were calculated from the peak areas under the 443 keV γ-ray of I-128 in the precipitate and comparative stand ard. Corrections for the chemical recovery were applied to them by means of the areas under the 365 keV γ-ray of I-131. This method was applied to the certified refe rece materials, IAEA wheat flour RM-V-5 and NBS orchard leaves SRM 1571. The results were in good agreement with the recommended values. Iodine contents of rice samples of two different origins in Japan were found to be of the order of 10 0 ng g -1 (dry weight base). The recovery of iodine in this procedure was about 80%. Decontamination factors for Mn, Cl, Na, and Br in the final fraction were 7 x 10 3 , 2 x 10 4 , 3 x 10 4 , and 2 x 10 2 , respectively. The time required for the chemical procedure was about 15 min, and the limit of determination was 0.7 ng of iodine in a sample of 1 g. (author)

Simple analytical methods for computing the gravity-wave contribution to the cosmic background radiation anisotropy

International Nuclear Information System (INIS)

Wang, Y.

1996-01-01

We present two simple analytical methods for computing the gravity-wave contribution to the cosmic background radiation (CBR) anisotropy in inflationary models; one method uses a time-dependent transfer function, the other methods uses an approximate gravity-mode function which is a simple combination of the lowest order spherical Bessel functions. We compare the CBR anisotropy tensor multipole spectrum computed using our methods with the previous result of the highly accurate numerical method, the open-quote open-quote Boltzmann close-quote close-quote method. Our time-dependent transfer function is more accurate than the time-independent transfer function found by Turner, White, and Lindsey; however, we find that the transfer function method is only good for l approx-lt 120. Using our approximate gravity-wave mode function, we obtain much better accuracy; the tensor multipole spectrum we find differs by less than 2% for l approx-lt 50, less than 10% for l approx-lt 120, and less than 20% for l≤300 from the open-quote open-quote Boltzmann close-quote close-quote result. Our approximate graviton mode function should be quite useful in studying tensor perturbations from inflationary models. copyright 1996 The American Physical Society

Deposition of GdVO4:Eu3+ nanoparticles on silica nanospheres by a simple sol gel method

Science.gov (United States)

Liu, Guixia; Hong, Guangyan; Wang, Jinxian; Dong, Xiangting

2006-07-01

The deposition and coating of GdVO4:Eu3+ nanoparticles on spherical silica was carried out using a simple sol-gel method at low temperature. The GdVO4:Eu3+-coated silica composites obtained were characterized by differential thermal analysis (DTA), thermogravimetric (TG) analysis, x-ray diffraction (XRD), Fourier-transform IR spectroscopy (FT-IR), transmission electron microscopy (TEM), x-ray photoelectron spectroscopy (XPS), photoluminescence spectra, and kinetic decay. It is found that the ~5 nm GdVO4:Eu3+ nanoparticles coating the silica spheres are crystal in the as-prepared samples and the crystallinity increases with increasing annealing temperature. The composites obtained are spherical in shape with an average size of 100 nm. The GdVO4:Eu3+ nanoparticles are linked with silica cores by a chemical bond. The photoluminescence spectra of the obtained GdVO4:Eu3+-coated silica composites are similar to those of the bulk GdVO4:Eu3+ phosphors. The strongest peak is near 617 nm, which indicates that Eu3+ is located in the low symmetry site with non-inversion centre.

Versatile Dual Photoresponsive System for Precise Control of Chemical Reactions.

Science.gov (United States)

Xu, Can; Bing, Wei; Wang, Faming; Ren, Jinsong; Qu, Xiaogang

2017-08-22

A versatile method for photoregulation of chemical reactions was developed through a combination of near-infrared (NIR) and ultraviolet (UV) light sensitive materials. This regulatory effect was achieved through photoresponsive modulation of reaction temperature and pH values, two prominent factors influencing reaction kinetics. Photothermal nanomaterial graphene oxide (GO) and photobase reagent malachite green carbinol base (MGCB) were selected for temperature and pH regulation, respectively. Using nanocatalyst- and enzyme-mediated chemical reactions as model systems, we demonstrated the feasibility and high efficiency of this method. In addition, a photoresponsive, multifunctional "Band-aid"-like hydrogel platform was presented for programmable wound healing. Overall, this simple, efficient, and reversible system was found to be effective for controlling a wide variety of chemical reactions. Our work may provide a method for remote and sustainable control over chemical reactions for industrial and biomedical applications.

Evaluation of a chemical risk assessment method of South Korea for chemicals classified as carcinogenic, mutagenic or reprotoxic (CMR).

Science.gov (United States)

Kim, Min-Uk; Byeon, Sang-Hoon

2017-12-12

Chemicals were used in various fields by the development of industry and science and technology. The Chemical Hazard Risk Management (CHARM) was developed to assess the risk of chemicals in South Korea. In this study, we were to evaluate the CHARM model developed for the effective management of workplace chemicals. We used 59 carcinogenic, mutagenic or reprotoxic (CMR) materials, which are both the work environment measurement result and the usage information among the manufacturer data. The CHARM model determines the risk to human health using the exposure level (based on working environment measurements or a combination of the quantity used and chemical physical properties (e.g., fugacity and volatility)), hazard (using occupational exposure limit (OEL) or Risk phrases (R-phrases)/Hazard statements (H-statements) from the Material Safety Data Sheet (MSDS)). The risk level was lower when using the results of the work environment measurement than when applying the chemical quantity and physical properties in the exposure level evaluation method. It was evaluated as grade 4 for the CMR material in the hazard class determination. The risk assessment method by R-phrases was evaluated more conservatively than the risk assessment method by OEL. And the risk assessment method by H-statements was evaluated more conservatively than the risk assessment method by R-phrases. The CHARM model was gradually conservatively assessed as it proceeded in the next step without quantitative information for individual workplaces. The CHARM is expected to help identify the risk if the hazards and exposure levels of chemicals were identified in individual workplaces. For CMR substances, although CHARM is highly evaluated for hazards, the risk is assessed to be low if exposure levels are assessed low. When evaluating the risk of highly hazardous chemicals such as CMR substances, we believe the model should be adapted to be more conservative and classify these as higher risk. This work is

A simple method to design non-collision relative orbits for close spacecraft formation flying

Science.gov (United States)

Jiang, Wei; Li, JunFeng; Jiang, FangHua; Bernelli-Zazzera, Franco

2018-05-01

A set of linearized relative motion equations of spacecraft flying on unperturbed elliptical orbits are specialized for particular cases, where the leader orbit is circular or equatorial. Based on these extended equations, we are able to analyze the relative motion regulation between a pair of spacecraft flying on arbitrary unperturbed orbits with the same semi-major axis in close formation. Given the initial orbital elements of the leader, this paper presents a simple way to design initial relative orbital elements of close spacecraft with the same semi-major axis, thus preventing collision under non-perturbed conditions. Considering the mean influence of J 2 perturbation, namely secular J 2 perturbation, we derive the mean derivatives of orbital element differences, and then expand them to first order. Thus the first order expansion of orbital element differences can be added to the relative motion equations for further analysis. For a pair of spacecraft that will never collide under non-perturbed situations, we present a simple method to determine whether a collision will occur when J 2 perturbation is considered. Examples are given to prove the validity of the extended relative motion equations and to illustrate how the methods presented can be used. The simple method for designing initial relative orbital elements proposed here could be helpful to the preliminary design of the relative orbital elements between spacecraft in a close formation, when collision avoidance is necessary.

Chemical kinetics and reaction mechanism

International Nuclear Information System (INIS)

Jung, Ou Sik; Park, Youn Yeol

1996-12-01

This book is about chemical kinetics and reaction mechanism. It consists of eleven chapters, which deal with reaction and reaction speed on reaction mechanism, simple reaction by rate expression, reversible reaction and simultaneous reaction, successive reaction, complicated reaction mechanism, assumption for reaction mechanism, transition state theory, successive reaction and oscillating reaction, reaction by solution, research method high except kinetics on reaction mechanism, high reaction of kinetics like pulsed radiolysis.

Using deuterated PAH amendments to validate chemical extraction methods to predict PAH bioavailability in soils

International Nuclear Information System (INIS)

Gomez-Eyles, Jose L.; Collins, Chris D.; Hodson, Mark E.

2011-01-01

Validating chemical methods to predict bioavailable fractions of polycyclic aromatic hydrocarbons (PAHs) by comparison with accumulation bioassays is problematic. Concentrations accumulated in soil organisms not only depend on the bioavailable fraction but also on contaminant properties. A historically contaminated soil was freshly spiked with deuterated PAHs (dPAHs). dPAHs have a similar fate to their respective undeuterated analogues, so chemical methods that give good indications of bioavailability should extract the fresh more readily available dPAHs and historic more recalcitrant PAHs in similar proportions to those in which they are accumulated in the tissues of test organisms. Cyclodextrin and butanol extractions predicted the bioavailable fraction for earthworms (Eisenia fetida) and plants (Lolium multiflorum) better than the exhaustive extraction. The PAHs accumulated by earthworms had a larger dPAH:PAH ratio than that predicted by chemical methods. The isotope ratio method described here provides an effective way of evaluating other chemical methods to predict bioavailability. - Research highlights: → Isotope ratios can be used to evaluate chemical methods to predict bioavailability. → Chemical methods predicted bioavailability better than exhaustive extractions. → Bioavailability to earthworms was still far from that predicted by chemical methods. - A novel method using isotope ratios to assess the ability of chemical methods to predict PAH bioavailability to soil biota.

Using deuterated PAH amendments to validate chemical extraction methods to predict PAH bioavailability in soils

Energy Technology Data Exchange (ETDEWEB)

Gomez-Eyles, Jose L., E-mail: j.l.gomezeyles@reading.ac.uk [University of Reading, School of Human and Environmental Sciences, Soil Research Centre, Reading, RG6 6DW Berkshire (United Kingdom); Collins, Chris D.; Hodson, Mark E. [University of Reading, School of Human and Environmental Sciences, Soil Research Centre, Reading, RG6 6DW Berkshire (United Kingdom)

2011-04-15

Validating chemical methods to predict bioavailable fractions of polycyclic aromatic hydrocarbons (PAHs) by comparison with accumulation bioassays is problematic. Concentrations accumulated in soil organisms not only depend on the bioavailable fraction but also on contaminant properties. A historically contaminated soil was freshly spiked with deuterated PAHs (dPAHs). dPAHs have a similar fate to their respective undeuterated analogues, so chemical methods that give good indications of bioavailability should extract the fresh more readily available dPAHs and historic more recalcitrant PAHs in similar proportions to those in which they are accumulated in the tissues of test organisms. Cyclodextrin and butanol extractions predicted the bioavailable fraction for earthworms (Eisenia fetida) and plants (Lolium multiflorum) better than the exhaustive extraction. The PAHs accumulated by earthworms had a larger dPAH:PAH ratio than that predicted by chemical methods. The isotope ratio method described here provides an effective way of evaluating other chemical methods to predict bioavailability. - Research highlights: > Isotope ratios can be used to evaluate chemical methods to predict bioavailability. > Chemical methods predicted bioavailability better than exhaustive extractions. > Bioavailability to earthworms was still far from that predicted by chemical methods. - A novel method using isotope ratios to assess the ability of chemical methods to predict PAH bioavailability to soil biota.

Customizable Generation of Synthetically Accessible, Local Chemical Subspaces.

Science.gov (United States)

Pottel, Joshua; Moitessier, Nicolas

2017-03-27

Screening large libraries of chemicals has been an efficient strategy to discover bioactive compounds; however a portion of the potential for success is limited to the available libraries. Synergizing combinatorial and computational chemistries has emerged as a time-efficient strategy to explore the chemical space more widely. Ideally, streamlining the evaluation process for larger, feasible chemical libraries would become commonplace. Thus, combinatorial tools and, for example, docking methods would be integrated to identify novel bioactive entities. The idea is simple in nature, but much more complex in practice; combinatorial chemistry is more than the coupling of chemicals into products: synthetic feasibility includes chemoselectivity, stereoselectivity, protecting group chemistry, and chemical availability which must all be considered for combinatorial library design. In addition, intuitive interfaces and simple user manipulation is key for optimal use of such tools by organic chemists-crucial for the integration of such software in medicinal chemistry laboratories. We present herein Finders and React2D-integrated into the Virtual Chemist platform, a modular software suite. This approach enhances virtual combinatorial chemistry by identifying available chemicals compatible with a user-defined chemical transformation and by carrying out the reaction leading to libraries of realistic, synthetically accessible chemicals-all with a completely automated, black-box, and efficient design. We demonstrate its utility by generating ∼40 million synthetically accessible, stereochemically accurate compounds from a single library of 100 000 purchasable molecules and 56 well-characterized chemical reactions.

Method of operating a thermal engine powered by a chemical reaction

Science.gov (United States)

Ross, J.; Escher, C.

1988-06-07

The invention involves a novel method of increasing the efficiency of a thermal engine. Heat is generated by a non-linear chemical reaction of reactants, said heat being transferred to a thermal engine such as Rankine cycle power plant. The novel method includes externally perturbing one or more of the thermodynamic variables of said non-linear chemical reaction. 7 figs.

Simple and effective method for nuclear tellurium isomers separation from antimony cyclotron targets

International Nuclear Information System (INIS)

Bondarevskij, S.I.; Eremin, V.V.

1999-01-01

Simple and effective method of generation of tellurium nuclear isomers from irradiated on cyclotron metallic antimony is suggested. Basically this method consists in consideration of the big difference in volatilities of metallic forms of antimony, tin and tellurium. Heating of the tin-antimony alloy at 1200 K permits to separate about 90 % of produced quantity of 121m Te and 123m Te (in this case impurity of antimony radionuclides is not more than 1 % on activity) [ru

A new method to study simple shear processing of wheat gluten-starch mixtures

NARCIS (Netherlands)

Peighambardoust, S.H.; Goot, A.J. van der; Hamer, R.J.; Boom, R.M.

2004-01-01

This article introduces a new method that uses a shearing device to study the effect of simple shear on the overall properties of pasta-like products made from commercial wheat gluten-starch (GS) blends. The shear-processed GS samples had a lower cooking loss (CL) and a higher swelling index (SI)

A simple method for validation and verification of pipettes mounted on automated liquid handlers

DEFF Research Database (Denmark)

Stangegaard, Michael; Hansen, Anders Johannes; Frøslev, Tobias G

2011-01-01

We have implemented a simple, inexpensive, and fast procedure for validation and verification of the performance of pipettes mounted on automated liquid handlers (ALHs) as necessary for laboratories accredited under ISO 17025. A six- or seven-step serial dilution of OrangeG was prepared in quadru......We have implemented a simple, inexpensive, and fast procedure for validation and verification of the performance of pipettes mounted on automated liquid handlers (ALHs) as necessary for laboratories accredited under ISO 17025. A six- or seven-step serial dilution of OrangeG was prepared...... are freely available. In conclusion, we have set up a simple, inexpensive, and fast solution for the continuous validation of ALHs used for accredited work according to the ISO 17025 standard. The method is easy to use for aqueous solutions but requires a spectrophotometer that can read microtiter plates....

Determination of Some Cephalosporins in Pharmaceutical Formulations by a Simple and Sensitive Spectrofluorimetric Method

Directory of Open Access Journals (Sweden)

Ali Abdollahi, Ahad Bavili-Tabrizi

2016-03-01

Full Text Available Background: Cephalosporins are among the safest and the most effective broad-spectrum bactericidal antimicrobial agents which have been prescribed by the clinician as antibiotics. Thus, the developing of simple, sensitive and rapid analytical methods for their determination can be attractive and desirable. Methods: A simple, rapid and sensitive spectrofluorimetric method was developed for the determination of cefixime, cefalexin and ceftriaxone in pharmaceutical formulations. Proposed method is based on the oxidation of these cephalosporins with cerium (IV to produce cerium (III, and its fluorescence was monitored at 356 ± 3 nm after excitation at 254 ± 3 nm. Results: The variables effecting oxidation of each cephalosporin with cerum (IV were studied and optimized. Under the experimental conditions used, the calibration graphs were linear over the range 0.1-4 µg/mL. The limit of detection and limit of quantification were in the range 0.031-0.054 and 0.102-0.172 µg/mL, respectively. Intra- and inter-day assay precisions, expressed as the relative standard deviation (RSD, were lower than 5.6 and 6.8%, respectively. Conclusion: The proposed method was applied to the determination of studied cephalosporins in pharmaceutical formulations by good recoveries in the range 91-110%.

A simple method of shower localization and identification in laterally segmented calorimeters

International Nuclear Information System (INIS)

Awes, T.C.; Obenshain, F.E.; Plasil, F.; Saini, S.; Young, G.R.; Sorensen, S.P.

1992-01-01

A method is proposed to calculate the first and second moments of the spatial distribution of the energy of electromagnetic and hadronic showers measured in laterally segmented colorimeters. The technique uses a logarithmic weighting of energy fraction observed in the individual detector cells. It is fast and simple requiring no fitting or complicated corrections for the position or angle of incidence. The method is demonstrated with GEANT simulations of a BGO detector array. The position resolution results and the e/π separation results are found to be equal or superior to those obtained with more complicated techniques. (orig.)

A novel and simple method for analyzing elements using x-ray induced with femto-second laser

International Nuclear Information System (INIS)

Fukushima, M.; Yomogihata, K.; Ono, H.; Hatanaka, K.; Fukumura, H.

2005-01-01

It is well known that x-ray emission is induced when materials are irradiated by an intense femto-second laser. Since the x-ray properties of atoms are almost independent of chemical forms or physical states, the induced x-ray emission spectrum is useful for analytical purposes. A new and simple method for analyzing elements in solid and liquid samples has been developed using a femto-second laser with sufficient power to generate x-ray emission. Femto-second pulses from a Ti: sapphire laser system were focused with a microscopic objective lens on samples, and x-ray emission spectra were measured by solid state detector. Though the sensitivity for elements is not so high, this method has several advantages; (1) available to analyze under daylight, (2) available to analyze in the air, (3) no need for the license to radioactive source. Moreover, this laser system can be taken to outside. It means this method can be used for in site analysis. Various kinds of samples were tested; commercial crystal glass, NIST SRM-1633b Coal Fly Ash: GSJ Reference Sample JMn-1 Mn nodule sample, several kinds of geological rocks, law fish slice, and gelatin gel of salt solutions. As a-result, specific x-rays were observed from elements more than l wt% contents in the spectral range of 3-8 keV, For analyzing liquid samples, laser pulses were focused on the surface of water jet stream or filter paper in which solution has soaked. Details of the results will be presented.

Methods for the Determination of Chemical Contaminants in Drinking Water. Training Manual.

Science.gov (United States)

Office of Water Program Operations (EPA), Cincinnati, OH. National Training and Operational Technology Center.

This training manual, intended for chemists and technicians with little or no experience in chemical procedures required to monitor drinking water, covers analytical methods for inorganic and organic chemical contaminants listed in the interim primary drinking water regulations. Topics include methods for heavy metals, nitrate, and organic…

CuO nanostructures on copper foil by a simple wet chemical route at room temperature

International Nuclear Information System (INIS)

Jana, S.; Das, S.; Das, N.S.; Chattopadhyay, K.K.

2010-01-01

Uniform CuO nanostructures have been synthesized on copper foil substrates by oxidation of Cu in alkaline condition by a simple wet chemical route at room temperature. By controlling the alkaline condition (pH value) different CuO nanostructures like nanoneedles, self-assembled nanoflowers and staking of flake-like structures were achieved. The phase formation and the composition of the films were characterized by X-ray diffraction and energy dispersive analysis of X-ray studies. X-ray photoelectron spectroscopic studies indicated that the samples were composed of CuO. The morphologies of the films were investigated by scanning electron microscopy. A possible growth mechanism is also proposed here. Band gap energies of the nanostructures were determined from the optical reflectance spectra. The different CuO nanostructures showed good electron field emission properties with turn-on fields in the range 6-11.3 V μm -1 . The field emission current was significantly affected by the morphologies of the CuO films.

A simple method for deriving functional MSCs and applied for osteogenesis in 3D scaffolds

DEFF Research Database (Denmark)

Zou, Lijin; Luo, Yonglun; Chen, Muwan

2013-01-01

We describe a simple method for bone engineering using biodegradable scaffolds with mesenchymal stem cells derived from human induced-pluripotent stem cells (hiPS-MSCs). The hiPS-MSCs expressed mesenchymal markers (CD90, CD73, and CD105), possessed multipotency characterized by tri......-lineages differentiation: osteogenic, adipogenic, and chondrogenic, and lost pluripotency - as seen with the loss of markers OCT3/4 and TRA-1-81 - and tumorigenicity. However, these iPS-MSCs are still positive for marker NANOG. We further explored the osteogenic potential of the hiPS-MSCs in synthetic polymer......, our results suggest the iPS-MSCs derived by this simple method retain fully osteogenic function and provide a new solution towards personalized orthopedic therapy in the future....

Electrochemical and chemical methods of metallizing plastic films

OpenAIRE

Chapples, J.

1991-01-01

This thesis describes two novel techniques for the metallization of non-electroactive polymer films and thicker sectioned polyethylene and nylon substrates. In the first approach, non-electroactive polymer substrates were impregnated with surface layers of polypyrrole and polyaniline, using electrochemical and chemical methods of polymerization. The relative merits of both these approaches are discussed and compared with other methods in the literature. The resultant composi...

A simple method for identification of irradiated spices

International Nuclear Information System (INIS)

Behere, A.; Desai, S.R.P.; Nair, P.M.; Rao, S.M.D.

1992-01-01

Thermoluminescence (TL) properties of curry powder, a salt containing spice mixture, and three different ground spices, viz, chilli, turmeric and pepper, were compared with TL of table salt. The spices other than curry powder, did not exhibit characteristic TL in the absence of salt. Therefore studies were initiated to develop a simple and reliable method using common salt for distinguishing irradiated spices (10 kGy) from unirradiated ones under normal conditions of storage. Common salt exhibited a characteristic TL glow at 170 o C. However, when present in curry powder, the TL glow of salt showed a shift to 208 o C. It was further observed that upon storage up to 6 months, the TL of irradiated curry powder retained about 10% of the original intensity and still could be distinguished from the untreated samples. From our results it is evident that common salt could be used as an indicator either internally or externally in small sachets for incorporating into prepacked spices. (author)

A simple method for identification of irradiated spices

Energy Technology Data Exchange (ETDEWEB)

Behere, A; Desai, S R.P.; Nair, P M [Bhabha Atomic Research Centre, Bombay (India). Food Technology and Enzyme Engineering Div.; Rao, S M.D. [Bhabha Atomic Research Centre, Bombay (India). Technical Physics and Prototype Engineering Div.

1992-07-01

Thermoluminescence (TL) properties of curry powder, a salt containing spice mixture, and three different ground spices, viz, chilli, turmeric and pepper, were compared with TL of table salt. The spices other than curry powder, did not exhibit characteristic TL in the absence of salt. Therefore studies were initiated to develop a simple and reliable method using common salt for distinguishing irradiated spices (10 kGy) from unirradiated ones under normal conditions of storage. Common salt exhibited a characteristic TL glow at 170{sup o}C. However, when present in curry powder, the TL glow of salt showed a shift to 208{sup o}C. It was further observed that upon storage up to 6 months, the TL of irradiated curry powder retained about 10% of the original intensity and still could be distinguished from the untreated samples. From our results it is evident that common salt could be used as an indicator either internally or externally in small sachets for incorporating into prepacked spices. (author).

Simple method of measuring pulmonary extravascular water using heavy water

Energy Technology Data Exchange (ETDEWEB)

Basset, G; Moreau, F; Scaringella, M; Tistchenko, S; Botter, F; Marsac, J

1975-11-20

The field of application of the multiple indicators dilution method in human pathology, already used to study pulmonary edema, can be extended to cover the identification and testing of all conditions leading to increase lung water. To be really practical it must be simple, fast, sensitive, inexpensive and subject to repetition; the use of non-radioactive tracers is implied. Indocyanine Green and heavy water were chosen respectively as vascular and diffusible indicators. Original methods have been developed for the treatment and isotopic analysis of blood: mass spectrometric analysis of aqueous blood extracts after deproteinisation by zinc sulphate then rapid distillation of the supernatant under helium; infrared analysis either of acetone extracts from small blood samples (100..mu..litre) or of blood itself in a continuous measurement. The infrared technique adopted has been used on rats and on men in normal and pathological situations. The results show that the method proposed for the determination of pulmonary extravascular water meets the requirements of clinicians while respecting the patients' safety, and could be generalized to other organs.

Chemical removal of radionuclides in contaminated spinach derived from the Fukushima nuclear accident

International Nuclear Information System (INIS)

Shiba, Kazuhiro; Kitamura, Yoji; Kozaka, Takashi; Uno, Izumi; Miyoshi, Hirokazu; Yanaga, Makoto

2012-01-01

We examined a simple and effective removal method for contaminated farm products to ensure the relief of farmers and the security of consumers. Removal of radionuclides from spinach by chemical methods was investigated. The result of chemical removal showed that antioxidant agents removed radionuclides from spinach by 70–80% for 131 I and more than 80% for radiocesium. In particular, ascorbic acid is promising as a safe and versatile option. (author)

A simple source preparation method for alpha-ray spectrometry of volcanic rock sample

International Nuclear Information System (INIS)

Takahashi, Masaomi; Kurihara, Yuichi; Sato, Jun

2006-01-01

A simple source preparation method was developed for the alpha-ray spectrometry to determine U and Th in volcanic rockes. Isolation of U and Th from volcanic rocks was made by use of UTEVA-Spec. resin, extraction chromatograph material. U and Th were extracted by TTA-benzene solution and organic phase was evaporated drop by drop on a hot stainless steel planchet to dryness. This method was found to be effective for the preparation of sources for alpha-ray spectrometry. (author)

An improved probit method for assessment of domino effect to chemical process equipment caused by overpressure.

Science.gov (United States)

Mingguang, Zhang; Juncheng, Jiang

2008-10-30

Overpressure is one important cause of domino effect in accidents of chemical process equipments. Damage probability and relative threshold value are two necessary parameters in QRA of this phenomenon. Some simple models had been proposed based on scarce data or oversimplified assumption. Hence, more data about damage to chemical process equipments were gathered and analyzed, a quantitative relationship between damage probability and damage degrees of equipment was built, and reliable probit models were developed associated to specific category of chemical process equipments. Finally, the improvements of present models were evidenced through comparison with other models in literatures, taking into account such parameters: consistency between models and data, depth of quantitativeness in QRA.

Method for Non-Invasive Determination of Chemical Properties of Aqueous Solutions

Science.gov (United States)

Todd, Paul W. (Inventor); Jones, Alan (Inventor); Thomas, Nathan A. (Inventor)

2016-01-01

A method for non-invasively determining a chemical property of an aqueous solution is provided. The method provides the steps of providing a colored solute having a light absorbance spectrum and transmitting light through the colored solute at two different wavelengths. The method further provides the steps of measuring light absorbance of the colored solute at the two different transmitted light wavelengths, and comparing the light absorbance of the colored solute at the two different wavelengths to determine a chemical property of an aqueous solution.

Comparative physical, chemical and biological assessment of simple and titanium-doped ovine dentine-derived hydroxyapatite coatings fabricated by pulsed laser deposition

Science.gov (United States)

Duta, L.; Mihailescu, N.; Popescu, A. C.; Luculescu, C. R.; Mihailescu, I. N.; Çetin, G.; Gunduz, O.; Oktar, F. N.; Popa, A. C.; Kuncser, A.; Besleaga, C.; Stan, G. E.

2017-08-01

We report on the synthesis by Pulsed Laser Deposition of simple and Ti doped hydroxyapatite thin films of biological (ovine dentine) origin. Detailed physical, chemical, mechanical and biological investigations were performed. Morphological examination of films showed a surface composed of spheroidal particulates, of micronic size. Compositional analyses pointed to the presence of typical natural doping elements of bone, along with a slight non-stoichiometry of the deposited films. Structural investigations proved the monophasic hydroxyapatite nature of both simple and Ti doped films. Ti doping of biological hydroxyapatite induced an overall downgrade of the films crystallinity together with an increase of the films roughness. It is to be emphasized that bonding strength values measured at film/Ti substrate interface were superior to the minimum value imposed by International Standards regulating the load-bearing implant coatings. In vitro tests on Ti doped structures, compared to simple ones, revealed excellent biocompatibility in human mesenchymal stem cell cultures, a higher proliferation rate and a good cytocompatibility. The obtained results aim to elucidate the overall positive role of Ti doping on the hydroxyapatite films performance, and demonstrate the possibility to use this novel type of coatings as feasible materials for future implantology applications.

A Simple and Clean Method for O-Isopropylidenation of Carbohydrates

Energy Technology Data Exchange (ETDEWEB)

Rong, Yuan Wei; Zhang, Qi Hua; Wang, Wei; Li, Bao Lin [Shaanxi Normal Univ., Xi' an (China)

2014-07-15

An efficient catalysis system for the synthesis of O-isopropylidene derivatives of sugars and polyhydroxy alcohols has been developed with sulfonated polystyrene cation exchange resin CAT600 as a catalyst. The key advantages of this protocol are simple workup, good yields and the recoverability, the innocuity and low cost of the catalyst. As a green, general and efficient reaction system, this method is expected to attract much attention for the preparation of various O-isopropylidene sugar derivatives in a large scale. Protection of hydroxyl functions by O-isopropylidenation is an important method in the field of carbohydrate chemistry. Due to its convenient application in synthetic, configurational and conformational studies, the O-isopropylidene derivatives of sugars play an important role in the research of building blocks, such as glycosyl acceptors and glycosyl donors. Additionally, these derivatives of sugars are important in the synthesis of various natural products.

Simple method for the calculation and use of CVD phase diagrams with applications to the Ti-B-Cl-H system, 1200 to 8000K

International Nuclear Information System (INIS)

Randich, E.; Gerlach, T.M.

1980-03-01

A simple method for calculating multi-component gas-solid equilibrium phase diagrams for chemical vapor deposition (CVD) systems is presented. The method proceeds in three steps: dtermination of stable solid assemblages, evaluation of gas-solid stability relations, and calcuation of conventional phase diagrams using a new free energy minimization technique. The phase diagrams can be used to determine (1) bulk compositions and phase fields accessible by CVD techniques; (2) expected condensed phases for various starting gas mixtures; and (3) maximum equilibrium yields for specific CVD process variables. The three step thermodynamic method is used to calcuate phase diagrams for the example CVD system Ti-B-Cl-H at 1200 and 800 0 K. Examples of applications of the diagrams for yield optimization and experimental accessibility studies are presented and discussed. Experimental verification of the TiB 2 + Gas/Gas phase field boundary at 1200 0 K, H/Cl = 1 confirms the calculated boundary and indicates that equilibrium is nearly and rapidly approached under laboratory conditions

The Effect of Herrmann Whole Brain Teaching Method on Students' Understanding of Simple Electric Circuits

Science.gov (United States)

Bawaneh, Ali Khalid Ali; Nurulazam Md Zain, Ahmad; Salmiza, Saleh

2011-01-01

The purpose of this study was to investigate the effect of Herrmann Whole Brain Teaching Method over conventional teaching method on eight graders in their understanding of simple electric circuits in Jordan. Participants (N = 273 students; M = 139, F = 134) were randomly selected from Bani Kenanah region-North of Jordan and randomly assigned to…

A Simple Method for Assessing Severity of Common Root Rot on Barley

Directory of Open Access Journals (Sweden)

Mohammad Imad Eddin Arabi

2013-12-01

Full Text Available Common root rot caused by Cochliobolus sativus is a serious disease of barley. A simple and reliable method for assessing this disease would enhance our capacity in identifying resistance sources and developing resistant barley cultivars. In searching for such a method, a conidial suspension of C. sativus was dropped onto sterilized elongated subcrown internodes and incubated in sandwich filter paper using polyethylene transparent envelopes. Initial disease symptoms were easily detected after 48h of inoculation. Highly significant correlation coefficients were found in each experiment (A, B and C between sandwich filter paper and seedling assays, indicating that this testing procedure was reliable. The method presented facilitates a rapid pre-selection under uniform conditions which is of importance from a breeder’s point of view.

SU-8 cantilevers for bio/chemical sensing; Fabrication, characterisation and development of novel read-out methods

DEFF Research Database (Denmark)

Nordström, M.; Keller, Stephan Urs; Lillemose, Michael

2008-01-01

Here, we present the activities within our research group over the last five years with cantilevers fabricated in the polymer SU-8. We believe that SU-8 is an interesting polymer for fabrication of cantilevers for bio/chemical sensing due to its simple processing and low Young's modulus. We show...

Lipid Adjustment for Chemical Exposures: Accounting for Concomitant Variables

Science.gov (United States)

Li, Daniel; Longnecker, Matthew P.; Dunson, David B.

2013-01-01

Background Some environmental chemical exposures are lipophilic and need to be adjusted by serum lipid levels before data analyses. There are currently various strategies that attempt to account for this problem, but all have their drawbacks. To address such concerns, we propose a new method that uses Box-Cox transformations and a simple Bayesian hierarchical model to adjust for lipophilic chemical exposures. Methods We compared our Box-Cox method to existing methods. We ran simulation studies in which increasing levels of lipid-adjusted chemical exposure did and did not increase the odds of having a disease, and we looked at both single-exposure and multiple-exposures cases. We also analyzed an epidemiology dataset that examined the effects of various chemical exposures on the risk of birth defects. Results Compared with existing methods, our Box-Cox method produced unbiased estimates, good coverage, similar power, and lower type-I error rates. This was the case in both single- and multiple-exposure simulation studies. Results from analysis of the birth-defect data differed from results using existing methods. Conclusion Our Box-Cox method is a novel and intuitive way to account for the lipophilic nature of certain chemical exposures. It addresses some of the problems with existing methods, is easily extendable to multiple exposures, and can be used in any analyses that involve concomitant variables. PMID:24051893

Assessment of chemical exposures: calculation methods for environmental professionals

National Research Council Canada - National Science Library

Daugherty, Jack E

1997-01-01

... on by scientists, businessmen, and policymakers. Assessment of Chemical Exposures: Calculation Methods for Environmental Professionals addresses the expanding scope of exposure assessments in both the workplace and environment...

New chemical-DSMC method in numerical simulation of axisymmetric rarefied reactive flow

Science.gov (United States)

Zakeri, Ramin; Kamali Moghadam, Ramin; Mani, Mahmoud

2017-04-01

The modified quantum kinetic (MQK) chemical reaction model introduced by Zakeri et al. is developed for applicable cases in axisymmetric reactive rarefied gas flows using the direct simulation Monte Carlo (DSMC) method. Although, the MQK chemical model uses some modifications in the quantum kinetic (QK) method, it also employs the general soft sphere collision model and Stockmayer potential function to properly select the collision pairs in the DSMC algorithm and capture both the attraction and repulsion intermolecular forces in rarefied gas flows. For assessment of the presented model in the simulation of more complex and applicable reacting flows, first, the air dissociation is studied in a single cell for equilibrium and non-equilibrium conditions. The MQK results agree well with the analytical and experimental data and they accurately predict the characteristics of the rarefied flowfield with chemical reaction. To investigate accuracy of the MQK chemical model in the simulation of the axisymmetric flow, air dissociation is also assessed in an axial hypersonic flow around two geometries, the sphere as a benchmark case and the blunt body (STS-2) as an applicable test case. The computed results including the transient, rotational and vibrational temperatures, species concentration in the stagnation line, and also the heat flux and pressure coefficient on the surface are compared with those of the other chemical methods like the QK and total collision energy (TCE) models and available analytical and experimental data. Generally, the MQK chemical model properly simulates the chemical reactions and predicts flowfield characteristics more accurate rather than the typical QK model. Although in some cases, results of the MQK approaches match with those of the TCE method, the main point is that the MQK does not need any experimental data or unrealistic assumption of specular boundary condition as used in the TCE method. Another advantage of the MQK model is the

A simple and efficient total genomic DNA extraction method for individual zooplankton.

Science.gov (United States)

Fazhan, Hanafiah; Waiho, Khor; Shahreza, Md Sheriff

2016-01-01

Molecular approaches are widely applied in species identification and taxonomic studies of minute zooplankton. One of the most focused zooplankton nowadays is from Subclass Copepoda. Accurate species identification of all life stages of the generally small sized copepods through molecular analysis is important, especially in taxonomic and systematic assessment of harpacticoid copepod populations and to understand their dynamics within the marine community. However, total genomic DNA (TGDNA) extraction from individual harpacticoid copepods can be problematic due to their small size and epibenthic behavior. In this research, six TGDNA extraction methods done on individual harpacticoid copepods were compared. The first new simple, feasible, efficient and consistent TGDNA extraction method was designed and compared with the commercial kit and modified available TGDNA extraction methods. The newly described TGDNA extraction method, "Incubation in PCR buffer" method, yielded good and consistent results based on the high success rate of PCR amplification (82%) compared to other methods. Coupled with its relatively consistent and economical method the "Incubation in PCR buffer" method is highly recommended in the TGDNA extraction of other minute zooplankton species.

A statistical method for evaluation of the experimental phase equilibrium data of simple clathrate hydrates

DEFF Research Database (Denmark)

Eslamimanesh, Ali; Gharagheizi, Farhad; Mohammadi, Amir H.

2012-01-01

We, herein, present a statistical method for diagnostics of the outliers in phase equilibrium data (dissociation data) of simple clathrate hydrates. The applied algorithm is performed on the basis of the Leverage mathematical approach, in which the statistical Hat matrix, Williams Plot, and the r......We, herein, present a statistical method for diagnostics of the outliers in phase equilibrium data (dissociation data) of simple clathrate hydrates. The applied algorithm is performed on the basis of the Leverage mathematical approach, in which the statistical Hat matrix, Williams Plot...... in exponential form is used to represent/predict the hydrate dissociation pressures for three-phase equilibrium conditions (liquid water/ice–vapor-hydrate). The investigated hydrate formers are methane, ethane, propane, carbon dioxide, nitrogen, and hydrogen sulfide. It is interpreted from the obtained results...

Simple method for evaluating Goldstone diagrams in an angular momentum coupled representation

International Nuclear Information System (INIS)

Kuo, T.T.S.; Shurpin, J.; Tam, K.C.; Osnes, E.; Ellis, P.J.

1981-01-01

A simple and convenient method is derived for evaluating linked Goldstone diagrams in an angular momentum coupled representation. Our method is general, and can be used to evaluate any effective interaction and/or effective operator diagrams for both closed-shell nuclei (vacuum to vacuum linked diagrams) and open-shell nuclei (valence linked diagrams). The techniques of decomposing diagrams into ladder diagrams, cutting open internal lines and cutting off one-body insertions are introduced. These enable us to determine angular momentum factors associated with diagrams in the coupled representation directly, without the need for carrying out complicated angular momentum algebra. A summary of diagram rules is given

A simple method for the deconvolution of 134 Cs/137 Cs peaks in gamma-ray scintillation spectrometry

International Nuclear Information System (INIS)

Darko, E.O.; Osae, E.K.; Schandorf, C.

1998-01-01

A simple method for the deconvolution of 134 Cs / 137 Cs peaks in a given mixture of 134 Cs and 137 Cs using Nal(TI) gamma-ray scintillation spectrometry is described. In this method the 795 keV energy of 134 Cs is used as a reference peak to calculate the activity of the 137 Cs directly from the measured peaks. Certified reference materials were measured using the method and compared with a high resolution gamma-ray spectrometry measurements. The results showed good agreement with the certified values. The method is very simple and does not need any complicated mathematics and computer programme to de- convolute the overlapping 604.7 keV and 661.6 keV peaks of 134 Cs and 137 Cs respectively. (author). 14 refs.; 1 tab., 2 figs

Ruminal Methane Production on Simple Phenolic Acids Addition in in Vitro Gas Production Method

Directory of Open Access Journals (Sweden)

A. Jayanegara

2009-04-01

Full Text Available Methane production from ruminants contributes to total global methane production, which is an important contributor to global warming. In this experiment, six sources of simple phenolic acids (benzoic, cinnamic, phenylacetic, caffeic, p-coumaric and ferulic acids at two different levels (2 and 5 mM added to hay diet were evaluated for their potential to reduce enteric methane production using in vitro Hohenheim gas production method. The measured variables were gas production, methane, organic matter digestibility (OMD, and short chain fatty acids (SCFA. The results showed that addition of cinnamic, caffeic, p-coumaric and ferulic acids at 5 mM significantly (P p-coumaric > ferulic > cinnamic. The addition of simple phenols did not significantly decrease OMD. Addition of simple phenols tends to decrease total SCFA production. It was concluded that methane decrease by addition of phenolic acids was relatively small, and the effect of phenolic acids on methane decrease depended on the source and concentration applied.

Simple method for generating adjustable trains of picosecond electron bunches

Directory of Open Access Journals (Sweden)

P. Muggli

2010-05-01

Full Text Available A simple, passive method for producing an adjustable train of picosecond electron bunches is demonstrated. The key component of this method is an electron beam mask consisting of an array of parallel wires that selectively spoils the beam emittance. This mask is positioned in a high magnetic dispersion, low beta-function region of the beam line. The incoming electron beam striking the mask has a time/energy correlation that corresponds to a time/position correlation at the mask location. The mask pattern is transformed into a time pattern or train of bunches when the dispersion is brought back to zero downstream of the mask. Results are presented of a proof-of-principle experiment demonstrating this novel technique that was performed at the Brookhaven National Laboratory Accelerator Test Facility. This technique allows for easy tailoring of the bunch train for a particular application, including varying the bunch width and spacing, and enabling the generation of a trailing witness bunch.

A simple and accurate onset detection method for a measured bell-shaped speed profile

Directory of Open Access Journals (Sweden)

Lior Botzer

2009-06-01

Full Text Available Motor control neuroscientists measure limb trajectories and extract the onset of the movement for a variety of purposes. Such trajectories are often aligned relative to the onset of individual movement before the features of that movement are extracted and their properties are inspected. Onset detection is performed either manually or automatically, typically by selecting a velocity threshold. Here, we present a simple onset detection algorithm that is more accurate than the conventional velocity threshold technique. The proposed method is based on a simple regression and follows the minimum acceleration with constraints model, in which the initial phase of the bell-shaped movement is modeled by a cubic power of the time. We demonstrate the performance of the suggested method and compare it to the velocity threshold technique and to manual onset detection by a group of motor control experts. The database for this comparison consists of simulated minimum jerk trajectories and recorded reaching movements.

An Energy Efficiency Evaluation Method Based on Energy Baseline for Chemical Industry

OpenAIRE

Yao, Dong-mei; Zhang, Xin; Wang, Ke-feng; Zou, Tao; Wang, Dong; Qian, Xin-hua

2016-01-01

According to the requirements and structure of ISO 50001 energy management system, this study proposes an energy efficiency evaluation method based on energy baseline for chemical industry. Using this method, the energy plan implementation effect in the processes of chemical production can be evaluated quantitatively, and evidences for system fault diagnosis can be provided. This method establishes the energy baseline models which can meet the demand of the different kinds of production proce...

A Simple Method for High-Lift Propeller Conceptual Design

Science.gov (United States)

Patterson, Michael; Borer, Nick; German, Brian

2016-01-01

In this paper, we present a simple method for designing propellers that are placed upstream of the leading edge of a wing in order to augment lift. Because the primary purpose of these "high-lift propellers" is to increase lift rather than produce thrust, these props are best viewed as a form of high-lift device; consequently, they should be designed differently than traditional propellers. We present a theory that describes how these props can be designed to provide a relatively uniform axial velocity increase, which is hypothesized to be advantageous for lift augmentation based on a literature survey. Computational modeling indicates that such propellers can generate the same average induced axial velocity while consuming less power and producing less thrust than conventional propeller designs. For an example problem based on specifications for NASA's Scalable Convergent Electric Propulsion Technology and Operations Research (SCEPTOR) flight demonstrator, a propeller designed with the new method requires approximately 15% less power and produces approximately 11% less thrust than one designed for minimum induced loss. Higher-order modeling and/or wind tunnel testing are needed to verify the predicted performance.

Chemical analysis by nuclear methods. v. 2

International Nuclear Information System (INIS)

Alfassi, Z.B.

1998-01-01

'Chemical analysis by Nuclear Methods' is an effort of some renowned authors in field of nuclear chemistry and radiochemistry which is compiled by Alfassi, Z.B. and translated into Farsi version collected in two volumes. The second volume consists of the following chapters: Detecting ion recoil scattering and elastic scattering are dealt in the eleventh chapter, the twelfth chapter is devoted to nuclear reaction analysis using charged particles, X-ray emission is discussed at thirteenth chapter, the fourteenth chapter is about using ion microprobes, X-ray fluorescence analysis is discussed in the fifteenth chapter, alpha, beta and gamma ray scattering in chemical analysis are dealt in chapter sixteen, Moessbauer spectroscopy and positron annihilation are discussed in chapter seventeen and eighteen; The last two chapters are about isotope dilution analysis and radioimmunoassay

Structure of simple liquids; Structure des liquides simples

Energy Technology Data Exchange (ETDEWEB)

Blain, J F [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1969-07-01

The results obtained by application to argon and sodium of the two important methods of studying the structure of liquids: scattering of X-rays and neutrons, are presented on one hand. On the other hand the principal models employed for reconstituting the structure of simple liquids are exposed: mathematical models, lattice models and their derived models, experimental models. (author) [French] On presente d'une part les resultats obtenus par application a l'argon et au sodium des deux principales methodes d'etude de la structure des liquides: la diffusion des rayons X et la diffusion des neutrons; d'autre part, les principaux modeles employes pour reconstituer la structure des liquides simples sont exposes: modeles mathematiques, modeles des reseaux et modeles derives, modeles experimentaux. (auteur)

Simultaneous determination of some ultraviolet-absorbing chemicals in sunscreen cosmetics using a high-performance liquid chromatography method.

Science.gov (United States)

Liu, T; Wu, D

2011-10-01

A method of gradient elution high-performance liquid chromatography (HPLC) for simultaneous determination of 11 different ultraviolet-absorbing chemicals of phenylbenzlmldazole sulphonic acid, 4-aminobenzoic acid, benzophenone-4, benzophenone-3, isoamyl p-methoxycinnamate, 4-methylbenzylidene camphor, octocrylene, ethylhexyl methoxycinnamate, homosalate, ethylhexyl salicylate, methylene bis-benzotriazolyl tetramethylbutyl phenol was developed for the application to sunscreen cosmetic products. In this study, an Agilent SB-C18 analytical column (250 × 4.6 mm, 5 μm) was utilized and methanol, tetrahydrofuran and perchloric acid aqueous solution (0.2 mL HClO(4) + 300 mL H(2)O) were used for gradient elution at a total flow rate of 1.0 mL min(-1). The optimum conditions for 11 different ultraviolet-absorbing chemicals analyses were investigated. All calibration curves showed good linear regression with UV detection (311 nm) within test ranges. The correlation coefficients were better than 0.999 in all cases. The assay was simple, selective, convenient and reproducible and is suitable for the determination of ultraviolet-absorbing chemicals in commercial sunscreen cosmetic products. The use frequency of 11 different ultraviolet absorbents in 100 sunscreen cosmetics was investigated and statistically analysed. The ultraviolet absorbent of maximum use frequency was ethylhexyl methoxycinnamate. © 2011 The Authors. ICS © 2011 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Identification system for chemical warfare agents with PGNAA method

International Nuclear Information System (INIS)

Wang Bairong; Yin Guanghua; Yang Zhongpin

2007-01-01

The principle and the experimental commanding of Chemical warfare Agents Identification with PGNAA method are discussed in this paper. The choosing of detector, neutron source and the data processing method are detailed. Finally, a set of experimental instruments composed of Cf-232 and BGO detector is developed based on this theory discussed above. (authors)

Occurrence and simulation of trihalomethanes in swimming pool water: A simple prediction method based on DOC and mass balance.

Science.gov (United States)

Peng, Di; Saravia, Florencia; Abbt-Braun, Gudrun; Horn, Harald

2016-01-01

Trihalomethanes (THM) are the most typical disinfection by-products (DBPs) found in public swimming pool water. DBPs are produced when organic and inorganic matter in water reacts with chemical disinfectants. The irregular contribution of substances from pool visitors and long contact time with disinfectant make the forecast of THM in pool water a challenge. In this work occurrence of THM in a public indoor swimming pool was investigated and correlated with the dissolved organic carbon (DOC). Daily sampling of pool water for 26 days showed a positive correlation between DOC and THM with a time delay of about two days, while THM and DOC didn't directly correlate with the number of visitors. Based on the results and mass-balance in the pool water, a simple simulation model for estimating THM concentration in indoor swimming pool water was proposed. Formation of THM from DOC, volatilization into air and elimination by pool water treatment were included in the simulation. Formation ratio of THM gained from laboratory analysis using native pool water and information from field study in an indoor swimming pool reduced the uncertainty of the simulation. The simulation was validated by measurements in the swimming pool for 50 days. The simulated results were in good compliance with measured results. This work provides a useful and simple method for predicting THM concentration and its accumulation trend for long term in indoor swimming pool water. Copyright © 2015 Elsevier Ltd. All rights reserved.

Vortex breakdown in simple pipe bends

Science.gov (United States)

Ault, Jesse; Shin, Sangwoo; Stone, Howard

2016-11-01

Pipe bends and elbows are one of the most common fluid mechanics elements that exists. However, despite their ubiquity and the extensive amount of research related to these common, simple geometries, unexpected complexities still remain. We show that for a range of geometries and flow conditions, these simple flows experience unexpected fluid dynamical bifurcations resembling the bubble-type vortex breakdown phenomenon. Specifically, we show with simulations and experiments that recirculation zones develop within the bends under certain conditions. As a consequence, fluid and particles can remain trapped within these structures for unexpectedly-long time scales. We also present simple techniques to mitigate this recirculation effect which can potentially have impact across industries ranging from biomedical and chemical processing to food and health sciences.

A Simple Method to Determine if a Music Information Retrieval System is a "Horse"

DEFF Research Database (Denmark)

Sturm, Bob L.

2014-01-01

We propose and demonstrate a simple method to determine if a music information retrieval (MIR) system is using factors irrelevant to the task for which it is designed. This is of critical importance to certain use cases, but cannot be accomplished using standard approaches to evaluation in MIR...

Systematic methods for synthesis and design of sustainable chemical and biochemical processes

DEFF Research Database (Denmark)

Gani, Rafiqul

Chemical and biochemical process design consists of designing the process that can sustainably manufacture an identified chemical product through a chemical or biochemical route. The chemical product tree is potentially very large; starting from a set of basic raw materials (such as petroleum...... for process intensification, sustainable process design, identification of optimal biorefinery models as well as integrated process-control design, and chemical product design. The lecture will present the main concepts, the decomposition based solution approach, the developed methods and tools together...

Chemical Waste Management and Disposal.

Science.gov (United States)

Armour, Margaret-Ann

1988-01-01

Describes simple, efficient techniques for treating hazardous chemicals so that nontoxic and nonhazardous residues are formed. Discusses general rules for management of waste chemicals from school laboratories and general techniques for the disposal of waste or surplus chemicals. Lists specific disposal reactions. (CW)

Highly sensitive methanol chemical sensor based on undoped silver oxide nanoparticles prepared by a solution method

International Nuclear Information System (INIS)

Rahman, M.M.; Khan, S.B.; Asiri, A.M.; Jamal, A.; Faisal, M.

2012-01-01

We have prepared silver oxide nanoparticles (NPs) by a simple solution method using reducing agents in alkaline medium. The resulting NPs were characterized by UV-vis and FT-IR spectroscopy, X-ray powder diffraction, and field-emission scanning electron microscopy. They were deposited on a glassy carbon electrode to give a sensor with a fast response towards methanol in liquid phase. The sensor also displays good sensitivity and long-term stability, and enhanced electrochemical response. The calibration plot is linear (r 2 = 0.8294) over the 0.12 mM to 0.12 M methanol concentration range. The sensitivity is ∼ 2.65 μAcm -2 mM -1 , and the detection limit is 36.0 μM (at a SNR of 3). We also discuss possible future prospective uses of this metal oxide semiconductor nanomaterial in terms of chemical sensing. (author)

Silicon nanowire arrays as learning chemical vapour classifiers

International Nuclear Information System (INIS)

Niskanen, A O; Colli, A; White, R; Li, H W; Spigone, E; Kivioja, J M

2011-01-01

Nanowire field-effect transistors are a promising class of devices for various sensing applications. Apart from detecting individual chemical or biological analytes, it is especially interesting to use multiple selective sensors to look at their collective response in order to perform classification into predetermined categories. We show that non-functionalised silicon nanowire arrays can be used to robustly classify different chemical vapours using simple statistical machine learning methods. We were able to distinguish between acetone, ethanol and water with 100% accuracy while methanol, ethanol and 2-propanol were classified with 96% accuracy in ambient conditions.

A simple approach for synthesis, characterization and bioactivity of bovine bones to fabricate the polyurethane nanofiber containing hydroxyapatite nanoparticles

DEFF Research Database (Denmark)

Sheikh, F. A.; Kanjwal, Muzafar Ahmed; Macossay, J.

2012-01-01

In the present study, we had introduced polyurethane (PU) nanofibers that contain hydroxyapatite (HAp) nanoparticles (NPs) as a result of an electrospinning process. A simple method that does not depend on additional foreign chemicals had been employed to synthesize HAp NPs through the calcination...

Chemical deposition methods using supercritical fluid solutions

Science.gov (United States)

Sievers, Robert E.; Hansen, Brian N.

1990-01-01

A method for depositing a film of a desired material on a substrate comprises dissolving at least one reagent in a supercritical fluid comprising at least one solvent. Either the reagent is capable of reacting with or is a precursor of a compound capable of reacting with the solvent to form the desired product, or at least one additional reagent is included in the supercritical solution and is capable of reacting with or is a precursor of a compound capable of reacting with the first reagent or with a compound derived from the first reagent to form the desired material. The supercritical solution is expanded to produce a vapor or aerosol and a chemical reaction is induced in the vapor or aerosol so that a film of the desired material resulting from the chemical reaction is deposited on the substrate surface. In an alternate embodiment, the supercritical solution containing at least one reagent is expanded to produce a vapor or aerosol which is then mixed with a gas containing at least one additional reagent. A chemical reaction is induced in the resulting mixture so that a film of the desired material is deposited.

Methods of uranium isotpic separation by chemical exchange chromatography

International Nuclear Information System (INIS)

Pena V, L.A.; Valle M, L.

1985-01-01

Chemical exchange chromatography as applied to isotope separation has undergone a constant development during the last few years. The results so far indicate that this method could eventually become commercially useful. This work presents a critical review of the experimental methods presently under study by principal research groups, and which have not get been compared. (Author)

Chemical characteristics of fine particles emitted from different gas cooking methods

Science.gov (United States)

See, Siao Wei; Balasubramanian, Rajasekhar

Gas cooking is an important indoor source of fine particles (PM 2.5). The chemical characteristics of PM 2.5 emitted from different cooking methods, namely, steaming, boiling, stir-frying, pan-frying and deep-frying were investigated in a domestic kitchen. Controlled experiments were conducted to measure the mass concentration of PM 2.5 and its chemical constituents (elemental carbon (EC), organic carbon (OC), polycyclic aromatic hydrocarbons (PAHs), metals and ions) arising from these five cooking methods. To investigate the difference in particle properties of different cooking emissions, the amount and type of food, and the heat setting on the gas stove were kept constant during the entire course of the experiments. Results showed that deep-frying gave rise to the largest amount of PM 2.5 and most chemical components, followed by pan-frying, stir-frying, boiling, and steaming. Oil-based cooking methods released more organic pollutants (OC, PAHs, and organic ions) and metals, while water-based cooking methods accounted for more water-soluble (WS) ions. Their source profiles are also presented and discussed.

Heat Recovery from High Temperature Slags: A Review of Chemical Methods

Directory of Open Access Journals (Sweden)

Yongqi Sun

2015-03-01

Full Text Available Waste heat recovery from high temperature slags represents the latest potential way to remarkably reduce the energy consumption and CO2 emissions of the steel industry. The molten slags, in the temperature range of 1723–1923 K, carry large amounts of high quality energy. However, the heat recovery from slags faces several fundamental challenges, including their low thermal conductivity, inside crystallization, and discontinuous availability. During past decades, various chemical methods have been exploited and performed including methane reforming, coal and biomass gasification, and direct compositional modification and utilization of slags. These methods effectively meet the challenges mentioned before and help integrate the steel industry with other industrial sectors. During the heat recovery using chemical methods, slags can act as not only heat carriers but also as catalysts and reactants, which expands the field of utilization of slags. Fuel gas production using the waste heat accounts for the main R&D trend, through which the thermal heat in the slag could be transformed into high quality chemical energy in the fuel gas. Moreover, these chemical methods should be extended to an industrial scale to realize their commercial application, which is the only way by which the substantial energy in the slags could be extracted, i.e., amounting to 16 million tons of standard coal in China.

A simple mass-conserved level set method for simulation of multiphase flows

Science.gov (United States)

Yuan, H.-Z.; Shu, C.; Wang, Y.; Shu, S.

2018-04-01

In this paper, a modified level set method is proposed for simulation of multiphase flows with large density ratio and high Reynolds number. The present method simply introduces a source or sink term into the level set equation to compensate the mass loss or offset the mass increase. The source or sink term is derived analytically by applying the mass conservation principle with the level set equation and the continuity equation of flow field. Since only a source term is introduced, the application of the present method is as simple as the original level set method, but it can guarantee the overall mass conservation. To validate the present method, the vortex flow problem is first considered. The simulation results are compared with those from the original level set method, which demonstrates that the modified level set method has the capability of accurately capturing the interface and keeping the mass conservation. Then, the proposed method is further validated by simulating the Laplace law, the merging of two bubbles, a bubble rising with high density ratio, and Rayleigh-Taylor instability with high Reynolds number. Numerical results show that the mass is a well-conserved by the present method.

A simple method to measure cell viability in proliferation and cytotoxicity assays

Directory of Open Access Journals (Sweden)

Ricardo Carneiro Borra

2009-09-01

Full Text Available Resazurin dye has been broadly used as indicator of cell viability in several types of assays for evaluation of the biocompatibility of medical and dental materials. Mitochondrial enzymes, as carriers of diaphorase activities, are probably responsible for the transference of electrons from NADPH + H+ to resazurin, which is reduced to resorufin. The level of reduction can be quantified by spectrophotometers since resazurin exhibits an absorption peak at 600 ηm and resorufin at 570 ηm wavelengths. However, the requirement of a spectrophotometer and specific filters for the quantification could be a barrier to many laboratories. Digital cameras containing red, green and blue filters, which allow the capture of red (600 to 700 ηm and green (500 to 600 ηm light wavelengths in ranges bordering on resazurin and resorufin absorption bands, could be used as an alternative method for the assessment of resazurin and resorufin concentrations. Thus, our aim was to develop a simple, cheap and precise method based on a digital CCD camera to measure the reduction of resazurin. We compared the capability of the CCD-based method to distinguish different concentrations of L929 and normal Human buccal fibroblast cell lines with that of a conventional microplate reader. The correlation was analyzed through the Pearson coefficient. The results showed a strong association between the measurements of the method developed here and those made with the microplate reader (r² = 0.996; p < 0.01 and with the cellular concentrations (r² = 0.965; p < 0.01. We concluded that the developed Colorimetric Quantification System based on CCD Images allowed rapid assessment of the cultured cell concentrations with simple equipment at a reduced cost.

Comparison of traditional physico-chemical methods and molecular ...

African Journals Online (AJOL)

This study was aim to review the efficiency of molecular markers and traditional physico-chemical methods for the identification of basmati rice. The study involved 44 promising varieties of Indica rices collected from geographically distant places and adapted to irrigated and aerobic agro-ecosystems. Quality data for ...

Bubble nucleation in simple and molecular liquids via the largest spherical cavity method

International Nuclear Information System (INIS)

Gonzalez, Miguel A.; Abascal, José L. F.; Valeriani, Chantal; Bresme, Fernando

2015-01-01

In this work, we propose a methodology to compute bubble nucleation free energy barriers using trajectories generated via molecular dynamics simulations. We follow the bubble nucleation process by means of a local order parameter, defined by the volume of the largest spherical cavity (LSC) formed in the nucleating trajectories. This order parameter simplifies considerably the monitoring of the nucleation events, as compared with the previous approaches which require ad hoc criteria to classify the atoms and molecules as liquid or vapor. The combination of the LSC and the mean first passage time technique can then be used to obtain the free energy curves. Upon computation of the cavity distribution function the nucleation rate and free-energy barrier can then be computed. We test our method against recent computations of bubble nucleation in simple liquids and water at negative pressures. We obtain free-energy barriers in good agreement with the previous works. The LSC method provides a versatile and computationally efficient route to estimate the volume of critical bubbles the nucleation rate and to compute bubble nucleation free-energies in both simple and molecular liquids

Rapid continuous chemical methods for studies of nuclei far from stability

CERN Document Server

Trautmann, N; Eriksen, D; Gaggeler, H; Greulich, N; Hickmann, U; Kaffrell, N; Skarnemark, G; Stender, E; Zendel, M

1981-01-01

Fast continuous separation methods accomplished by combining a gas-jet recoil-transport system with a variety of chemical systems are described. Procedures for the isolation of individual elements from fission product mixtures with the multistage solvent extraction facility SISAK are presented. Thermochromatography in connection with a gas-jet has been studied as a technique for on-line separation of volatile fission halides. Based on chemical reactions in a gas-jet system itself separation procedures for tellurium, selenium and germanium from fission products have been worked out. All the continuous chemical methods can be performed within a few seconds. The application of such procedures to the investigation of nuclides far from the line of beta -stability is illustrated by a few examples. (16 refs).

Molecule database framework: a framework for creating database applications with chemical structure search capability.

Science.gov (United States)

Kiener, Joos

2013-12-11

Research in organic chemistry generates samples of novel chemicals together with their properties and other related data. The involved scientists must be able to store this data and search it by chemical structure. There are commercial solutions for common needs like chemical registration systems or electronic lab notebooks. However for specific requirements of in-house databases and processes no such solutions exist. Another issue is that commercial solutions have the risk of vendor lock-in and may require an expensive license of a proprietary relational database management system. To speed up and simplify the development for applications that require chemical structure search capabilities, I have developed Molecule Database Framework. The framework abstracts the storing and searching of chemical structures into method calls. Therefore software developers do not require extensive knowledge about chemistry and the underlying database cartridge. This decreases application development time. Molecule Database Framework is written in Java and I created it by integrating existing free and open-source tools and frameworks. The core functionality includes:•Support for multi-component compounds (mixtures)•Import and export of SD-files•Optional security (authorization)For chemical structure searching Molecule Database Framework leverages the capabilities of the Bingo Cartridge for PostgreSQL and provides type-safe searching, caching, transactions and optional method level security. Molecule Database Framework supports multi-component chemical compounds (mixtures).Furthermore the design of entity classes and the reasoning behind it are explained. By means of a simple web application I describe how the framework could be used. I then benchmarked this example application to create some basic performance expectations for chemical structure searches and import and export of SD-files. By using a simple web application it was shown that Molecule Database Framework

Emergency material allocation with time-varying supply-demand based on dynamic optimization method for river chemical spills.

Science.gov (United States)

Liu, Jie; Guo, Liang; Jiang, Jiping; Jiang, Dexun; Wang, Peng

2018-04-13

Aiming to minimize the damage caused by river chemical spills, efficient emergency material allocation is critical for an actual emergency rescue decision-making in a quick response. In this study, an emergency material allocation framework based on time-varying supply-demand constraint is developed to allocate emergency material, minimize the emergency response time, and satisfy the dynamic emergency material requirements in post-accident phases dealing with river chemical spills. In this study, the theoretically critical emergency response time is firstly obtained for the emergency material allocation system to select a series of appropriate emergency material warehouses as potential supportive centers. Then, an enumeration method is applied to identify the practically critical emergency response time, the optimum emergency material allocation and replenishment scheme. Finally, the developed framework is applied to a computational experiment based on south-to-north water transfer project in China. The results illustrate that the proposed methodology is a simple and flexible tool for appropriately allocating emergency material to satisfy time-dynamic demands during emergency decision-making. Therefore, the decision-makers can identify an appropriate emergency material allocation scheme in a balance between time-effective and cost-effective objectives under the different emergency pollution conditions.

Simple measurement of 14C in the environment using a gel suspension method

International Nuclear Information System (INIS)

Wakabayashi, G.; Ohura, H.; Okai, T.; Matoba, M.

1999-01-01

A simple analytical method for environmental 14 C with a low background liquid scintillation counter was developed. A new gelling agent, N-lauroyl-L-glutamic-α,γ-dibutylamide was used, for the liquid scintillation counting of 14 C as CaCO 3 (gel suspension method). Our procedure for sample preparation was much simpler than that of conventional methods and required no special equipment. The samples prepared with the standard sample of CaCO 3 were measured to evaluate the self absorption of the sample, the optimum condition of counting and the detection limit. Our results indicated that the newly developed technique could be efficiently applied for the monitoring of environmental 14 C. (author)

A simple, rapid and inexpensive screening method for the identification of Pythium insidiosum.

Science.gov (United States)

Tondolo, Juliana Simoni Moraes; Loreto, Erico Silva; Denardi, Laura Bedin; Mario, Débora Alves Nunes; Alves, Sydney Hartz; Santurio, Janio Morais

2013-04-01

Growth of Pythium insidiosum mycelia around minocycline disks (30μg) did not occur within 7days of incubation at 35°C when the isolates were grown on Sabouraud, corn meal, Muller-Hinton or RPMI agar. This technique offers a simple and rapid method for the differentiation of P. insidiosum from true filamentous fungi. Copyright © 2013 Elsevier B.V. All rights reserved.

X-ray photon-in/photon-out methods for chemical imaging

Energy Technology Data Exchange (ETDEWEB)

Marcus, Matthew A.

2010-03-24

Most interesting materials in nature are heterogeneous, so it is useful to have analytical techniques with spatial resolution sufficient to resolve these heterogeneities.This article presents the basics of X-ray photon-in/photon-out chemical imaging. This family of methods allows one to derive images reflectingthe chemical state of a given element in a complex sample, at micron or deep sub-micron scale. X-ray chemical imaging is relatively non-destructiveand element-selective, and requires minimal sample preparation. The article presents the basic concepts and some considerations of data takingand data analysis, along with some examples.

Increased Surface Roughness in Polydimethylsiloxane Films by Physical and Chemical Methods

Directory of Open Access Journals (Sweden)

Jorge Nicolás Cabrera

2017-08-01

Full Text Available Two methods, the first physical and the other chemical, were investigated to modify the surface roughness of polydimethylsiloxane (PDMS films. The physical method consisted of dispersing multi-walled carbon nanotubes (MWCNTs and magnetic cobalt ferrites (CoFe2O4 prior to thermal cross-linking, and curing the composite system in the presence of a uniform magnetic field H. The chemical method was based on exposing the films to bromine vapours and then UV-irradiating. The characterizing techniques included scanning electron microscopy (SEM, energy-dispersive spectroscopy (EDS, Fourier transform infrared (FTIR spectroscopy, optical microscopy, atomic force microscopy (AFM and magnetic force microscopy (MFM. The surface roughness was quantitatively analyzed by AFM. In the physical method, the random dispersion of MWCNTs (1% w/w and magnetic nanoparticles (2% w/w generated a roughness increase of about 200% (with respect to PDMS films without any treatment, but that change was 400% for films cured in the presence of H perpendicular to the surface. SEM, AFM and MFM showed that the magnetic particles always remained attached to the carbon nanotubes, and the effect on the roughness was interpreted as being due to a rupture of dispersion randomness and a possible induction of structuring in the direction of H. In the chemical method, the increase in roughness was even greater (1000%. Wells were generated with surface areas that were close to 100 μm2 and depths of up to 500 nm. The observations of AFM images and FTIR spectra were in agreement with the hypothesis of etching by Br radicals generated by UV on the polymer chains. Both methods induced important changes in the surface roughness (the chemical method generated the greatest changes due to the formation of surface wells, which are of great importance in superficial technological processes.

Preliminary comparison of different reduction methods of graphene ...

Indian Academy of Sciences (India)

diverse applications and developing a simple, green, and efficient method for the mass production of ... properties of graphene have driven the search to find methods ... Chemical reduction of GO sheets has been performed with ... efficient method for the mass production of graphene. 2. ... temperature was raised to 35.

A Simple Method for Determination of Critical Swimming Velocity in Swimming Flume

OpenAIRE

高橋, 繁浩; 若吉, 浩二; Shigehiro, TAKAHASHI; Kohji, WAKAYOSHI; 中京大学; 奈良教育大学教育学部

2001-01-01

The purpose of this study was to investigate a simple method for determination of critical swimming velocity (Vcri). Vcri is defined by Wakayoshi et al. (1992) as the swimming speed which could theoretically be maintained forever without exhaustion, and is expressed as the slope of a regression line between swimming distance (D) and swimming time (T) obtained at various swimming speeds. To determine Vcri, 20 well-trained swimmers were measured at several swimming speeds ranging from 1.25 m/se...

Simple method for assembly of CRISPR synergistic activation mediator gRNA expression array.

Science.gov (United States)

Vad-Nielsen, Johan; Nielsen, Anders Lade; Luo, Yonglun

2018-05-20

When studying complex interconnected regulatory networks, effective methods for simultaneously manipulating multiple genes expression are paramount. Previously, we have developed a simple method for generation of an all-in-one CRISPR gRNA expression array. We here present a Golden Gate Assembly-based system of synergistic activation mediator (SAM) compatible CRISPR/dCas9 gRNA expression array for the simultaneous activation of multiple genes. Using this system, we demonstrated the simultaneous activation of the transcription factors, TWIST, SNAIL, SLUG, and ZEB1 a human breast cancer cell line. Copyright © 2018 Elsevier B.V. All rights reserved.

Detailed balance method for chemical potential determination in Monte Carlo and molecular dynamics simulations

International Nuclear Information System (INIS)

Fay, P.J.; Ray, J.R.; Wolf, R.J.

1994-01-01

We present a new, nondestructive, method for determining chemical potentials in Monte Carlo and molecular dynamics simulations. The method estimates a value for the chemical potential such that one has a balance between fictitious successful creation and destruction trials in which the Monte Carlo method is used to determine success or failure of the creation/destruction attempts; we thus call the method a detailed balance method. The method allows one to obtain estimates of the chemical potential for a given species in any closed ensemble simulation; the closed ensemble is paired with a ''natural'' open ensemble for the purpose of obtaining creation and destruction probabilities. We present results for the Lennard-Jones system and also for an embedded atom model of liquid palladium, and compare to previous results in the literature for these two systems. We are able to obtain an accurate estimate of the chemical potential for the Lennard-Jones system at higher densities than reported in the literature

A simple microplate-based method for the determination of α-amylase activity using the glucose assay kit (GOD method).

Science.gov (United States)

Visvanathan, Rizliya; Jayathilake, Chathuni; Liyanage, Ruvini

2016-11-15

For the first time, a reliable, simple, rapid and high-throughput analytical method for the detection and quantification of α-amylase inhibitory activity using the glucose assay kit was developed. The new method facilitates rapid screening of a large number of samples, reduces labor, time and reagents and is also suitable for kinetic studies. This method is based on the reaction of maltose with glucose oxidase (GOD) and the development of a red quinone. The test is done in microtitre plates with a total volume of 260μL and an assay time of 40min including the pre-incubation steps. The new method is tested for linearity, sensitivity, precision, reproducibility and applicability. The new method is also compared with the most commonly used 3,5-dinitrosalicylic acid (DNSA) method for determining α-amylase activity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Methadone radioimmunoassay: two simple methods

International Nuclear Information System (INIS)

Robinson, K.; Smith, R.N.

1983-01-01

Two simple and economical radioimmunoassays for methadone in blood or urine are described. Haemolysis, decomposition, common anticoagulants and sodium fluoride do not affect the results. One assay used commercially-available [1- 3 H](-)-methadone hydrobromide as the label, while the other uses a radioiodinated conjugate of 4-dimethylamino-2,2-diphenylpentanoic acid and L-tyrosine methyl ester. A commercially-available antiserum is used in both assays. Normethadone and α-methadol cross-react to a small extent with the antiserum while methadone metabolites, dextropropoxyphene, dipipanone and phenadoxone have negligible cross-reactivities. The 'cut-offs' of the two assays as described are 30 and 33 ng ml -1 for blood, and 24 and 21 ng ml -1 for urine. The assay using the radioiodinated conjugate can be made more sensitive if required by increasing the specific activity of the label. (author)

A simple method for fabricating multi-layer PDMS structures for 3D microfluidic chips

KAUST Repository

Zhang, Mengying

2010-01-01

We report a simple methodology to fabricate PDMS multi-layer microfluidic chips. A PDMS slab was surface-treated by trichloro (1H,1H,2H,2H-perfluorooctyl) silane, and acts as a reusable transferring layer. Uniformity of the thickness of the patterned PDMS layer and the well-alignment could be achieved due to the transparency and proper flexibility of this transferring layer. Surface treatment results are confirmed by XPS and contact angle testing, while bonding forces between different layers were measured for better understanding of the transferring process. We have also designed and fabricated a few simple types of 3D PDMS chip, especially one consisting of 6 thin layers (each with thickness of 50 μm), to demonstrate the potential utilization of this technique. 3D fluorescence images were taken by a confocal microscope to illustrate the spatial characters of essential parts. This fabrication method is confirmed to be fast, simple, repeatable, low cost and possible to be mechanized for mass production. © The Royal Society of Chemistry 2010.

A simple method for rapidly processing HEU from weapons returns

Energy Technology Data Exchange (ETDEWEB)

McLean, W. II; Miller, P.E.

1994-01-01

A method based on the use of a high temperature fluidized bed for rapidly oxidizing, homogenizing and down-blending Highly Enriched Uranium (HEU) from dismantled nuclear weapons is presented. This technology directly addresses many of the most important issues that inhibit progress in international commerce in HEU; viz., transaction verification, materials accountability, transportation and environmental safety. The equipment used to carry out the oxidation and blending is simple, inexpensive and highly portable. Mobile facilities to be used for point-of-sale blending and analysis of the product material are presented along with a phased implementation plan that addresses the conversion of HEU derived from domestic weapons and related waste streams as well as material from possible foreign sources such as South Africa or the former Soviet Union.

A simple method to estimate radiation interception by nursery stock conifers: a case study of eastern white cedar

NARCIS (Netherlands)

Pronk, A.A.; Goudriaan, J.; Stilma, E.S.C.; Challa, H.

2003-01-01

A simple method was developed to estimate the fraction radiation intercepted by small eastern white cedar plants (Thuja occidentalis 'Brabant'). The method, which describes the crop canopy as rows of cuboids, was compared with methods used for estimating radiation interception by crops with

Microstructures and photocatalytic properties of porous ZnO films synthesized by chemical bath deposition method

International Nuclear Information System (INIS)

Wang Huihu; Dong, Shijie; Chang Ying; Zhou Xiaoping; Hu Xinbin

2012-01-01

Different porous ZnO film structures on the surface of alumina substrates were prepared through a simple chemical bath deposition method in the methanolic zinc acetate solution. The surface morphology and phase structure of porous ZnO film were determined by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. Both initial zinc acetate concentration and sintering temperature have great impact on the final film structures. With the increase of initial zinc acetate concentration, the porous structures can be finely tuned from circular nest like assemblies composed film into successive nest like film, and finally to globular aggregates composed film. By increasing the sintering temperature, the porous structure of successive nest like film can be further controlled. Furthermore, the crystallinity of photocatalysts also can be greatly improved. The photodegradation results of Methyl Orange revealed that porous ZnO film with successive nest like structure sintered at 500 °C exhibited the highest photocatalytic activity under UV illumination.

A simple method for assigning genomic grade to individual breast tumours

International Nuclear Information System (INIS)

Wennmalm, Kristian; Bergh, Jonas

2011-01-01

The prognostic value of grading in breast cancer can be increased with microarray technology, but proposed strategies are disadvantaged by the use of specific training data or parallel microscopic grading. Here, we investigate the performance of a method that uses no information outside the breast profile of interest. In 251 profiled tumours we optimised a method that achieves grading by comparing rank means for genes predictive of high and low grade biology; a simpler method that allows for truly independent estimation of accuracy. Validation was carried out in 594 patients derived from several independent data sets. We found that accuracy was good: for low grade (G1) tumors 83- 94%, for high grade (G3) tumors 74- 100%. In keeping with aim of improved grading, two groups of intermediate grade (G2) cancers with significantly different outcome could be discriminated. This validates the concept of microarray-based grading in breast cancer, and provides a more practical method to achieve it. A simple R script for grading is available in an additional file. Clinical implementation could achieve better estimation of recurrence risk for 40 to 50% of breast cancer patients

A simple method for assigning genomic grade to individual breast tumours

Directory of Open Access Journals (Sweden)

Bergh Jonas

2011-07-01

Full Text Available Abstract Background The prognostic value of grading in breast cancer can be increased with microarray technology, but proposed strategies are disadvantaged by the use of specific training data or parallel microscopic grading. Here, we investigate the performance of a method that uses no information outside the breast profile of interest. Results In 251 profiled tumours we optimised a method that achieves grading by comparing rank means for genes predictive of high and low grade biology; a simpler method that allows for truly independent estimation of accuracy. Validation was carried out in 594 patients derived from several independent data sets. We found that accuracy was good: for low grade (G1 tumors 83- 94%, for high grade (G3 tumors 74- 100%. In keeping with aim of improved grading, two groups of intermediate grade (G2 cancers with significantly different outcome could be discriminated. Conclusion This validates the concept of microarray-based grading in breast cancer, and provides a more practical method to achieve it. A simple R script for grading is available in an additional file. Clinical implementation could achieve better estimation of recurrence risk for 40 to 50% of breast cancer patients.

A simple method for improving predictions of nuclear masses

International Nuclear Information System (INIS)

Yamada, Masami; Tsuchiya, Susumu; Tachibana, Takahiro

1991-01-01

The formula for atomic masses which exactly conforms to all nuclides does not exist in reality and cannot be anticipated for the time being hereafter. At present the masses of many nuclides are known experimentally with good accuracy, but the values of whichever mass formulas are more or less different from those experimental values except small number of accidental coincidence. Under such situation, for forecasting the mass of an unknown nuclide, how is it cleverly done ? Generally speaking, to take the value itself of a mass formula seems not the best means. It may be better to take the difference of the values of a mass formula and experiment for the nuclide close to that to be forecast in consideration and to correct the forecast value of the mass formula. In this report, the simple method for this correction is proposed. The formula which connects between two extreme cases, the difference between a true mass and the value of a mass formula is the sum of proton part and neutron part, and the difference distributes randomly around zero, was proposed. The procedure for its concrete application is explained. This method can be applied to other physical quantities than mass, for example the half life of beta decay. (K.I.)

A Convergence Result for the Euler-Maruyama Method for a Simple Stochastic Differential Equation with Discontinuous Drift

DEFF Research Database (Denmark)

Simonsen, Maria; Schiøler, Henrik; Leth, John-Josef

2014-01-01

The Euler-Maruyama method is applied to a simple stochastic differential equation (SDE) with discontinuous drift. Convergence aspects are investigated in the case, where the Euler-Maruyama method is simulated in dyadic points. A strong rate of convergence is presented for the numerical simulations...

A simple method for plasma total vitamin C analysis suitable for routine clinical laboratory use

OpenAIRE

Robitaille, Line; Hoffer, L. John

2016-01-01

Background In-hospital hypovitaminosis C is highly prevalent but almost completely unrecognized. Medical awareness of this potentially important disorder is hindered by the inability of most hospital laboratories to determine plasma vitamin C concentrations. The availability of a simple, reliable method for analyzing plasma vitamin C could increase opportunities for routine plasma vitamin C analysis in clinical medicine. Methods Plasma vitamin C can be analyzed by high performance liquid chro...

The phase-resolved photoacoustic method to indicate chemical assignments of paracetamol

Science.gov (United States)

Camilotti, J. G.; Somer, A.; Costa, G. F.; Ribeiro, M. A.; Bonardi, C.; Cruz, G. K.; Gómez, S. L.; Beltrame, F. L.; Medina, A. N.; Sato, F.; Astrath, N. G. C.; Novatski, A.

2014-03-01

In this work, the phase-resolved photoacoustic method was applied to provide specific information on the chemical assignments of paracetamol in the near-infrared region. Two broad bands, centered at 1370 and 1130 nm, were well-resolved using this method, making it possible to assign the peaks centered at 1398, 1355 and 1295 nm to a C-H combination from a CH3 structure and the peak at 1305 nm to a C-H combination from the aromatic ring. This information represents a new finding in chemical studies regarding this medicament.

A simple method for the measurement of reflective foil emissivity

International Nuclear Information System (INIS)

Ballico, M. J.; Ham, E. W. M. van der

2013-01-01

Reflective metal foil is widely used to reduce radiative heat transfer within the roof space of buildings. Such foils are typically mass-produced by vapor-deposition of a thin metallic coating onto a variety of substrates, ranging from plastic-coated reinforced paper to 'bubble-wrap'. Although the emissivity of such surfaces is almost negligible in the thermal infrared, typically less than 0.03, an insufficiently thick metal coating, or organic contamination of the surface, can significantly increase this value. To ensure that the quality of the installed insulation is satisfactory, Australian building code AS/NZS 4201.5:1994 requires a practical agreed method for measurement of the emissivity, and the standard ASTM-E408 is implied. Unfortunately this standard is not a 'primary method' and requires the use of specified expensive apparatus and calibrated reference materials. At NMIA we have developed a simple primary technique, based on an apparatus to thermally modulate the sample and record the apparent modulation in infra-red radiance with commercially available radiation thermometers. The method achieves an absolute accuracy in the emissivity of approximately 0.004 (k=2). This paper theoretically analyses the equivalence between the thermal emissivity measured in this manner, the effective thermal emissivity in application, and the apparent emissivity measured in accordance with ASTM-E408

A simple method for the measurement of reflective foil emissivity

Science.gov (United States)

Ballico, M. J.; van der Ham, E. W. M.

2013-09-01

Reflective metal foil is widely used to reduce radiative heat transfer within the roof space of buildings. Such foils are typically mass-produced by vapor-deposition of a thin metallic coating onto a variety of substrates, ranging from plastic-coated reinforced paper to "bubble-wrap". Although the emissivity of such surfaces is almost negligible in the thermal infrared, typically less than 0.03, an insufficiently thick metal coating, or organic contamination of the surface, can significantly increase this value. To ensure that the quality of the installed insulation is satisfactory, Australian building code AS/NZS 4201.5:1994 requires a practical agreed method for measurement of the emissivity, and the standard ASTM-E408 is implied. Unfortunately this standard is not a "primary method" and requires the use of specified expensive apparatus and calibrated reference materials. At NMIA we have developed a simple primary technique, based on an apparatus to thermally modulate the sample and record the apparent modulation in infra-red radiance with commercially available radiation thermometers. The method achieves an absolute accuracy in the emissivity of approximately 0.004 (k=2). This paper theoretically analyses the equivalence between the thermal emissivity measured in this manner, the effective thermal emissivity in application, and the apparent emissivity measured in accordance with ASTM-E408.

Note: A simple image processing based fiducial auto-alignment method for sample registration.

Science.gov (United States)

Robertson, Wesley D; Porto, Lucas R; Ip, Candice J X; Nantel, Megan K T; Tellkamp, Friedjof; Lu, Yinfei; Miller, R J Dwayne

2015-08-01

A simple method for the location and auto-alignment of sample fiducials for sample registration using widely available MATLAB/LabVIEW software is demonstrated. The method is robust, easily implemented, and applicable to a wide variety of experiment types for improved reproducibility and increased setup speed. The software uses image processing to locate and measure the diameter and center point of circular fiducials for distance self-calibration and iterative alignment and can be used with most imaging systems. The method is demonstrated to be fast and reliable in locating and aligning sample fiducials, provided here by a nanofabricated array, with accuracy within the optical resolution of the imaging system. The software was further demonstrated to register, load, and sample the dynamically wetted array.

Method of manipulating the chemical properties of water to improve the effectiveness of a desired chemical process

Science.gov (United States)

Hawthorne, Steven B.; Miller, David J.; Yang, Yu; Lagadec, Arnaud Jean-Marie

1999-01-01

The method of the present invention is adapted to manipulate the chemical properties of water in order to improve the effectiveness of a desired chemical process. The method involves heating the water in the vessel to subcritical temperatures between 100.degree. to 374.degree. C. while maintaining sufficient pressure to the water to maintain the water in the liquid state. Various physiochemical properties of the water can be manipulated including polarity, solute solubility, surface tension, viscosity, and the disassociation constant. The method of the present invention has various uses including extracting organics from solids and semisolids such as soil, selectively extracting desired organics from nonaqueous liquids, selectively separating organics using sorbent phases, enhancing reactions by controlling the disassociation constant of water, cleaning waste water, and removing organics from water using activated carbon or other suitable sorbents.

Plasmonic metamaterial-based chemical converted graphene/TiO2/Ag thin films by a simple spray pyrolysis technique

Science.gov (United States)

Kumar, Promod; Swart, H. C.

2018-04-01

Graphene based hybrid nanostructures have received special attention in both the scientific and technological development due to their unique physicochemical behavior, which make them attractive in various applications such as, batteries, supercapacitors, fuel cells, solar cells, photovoltaic devices and bio-sensors. In the present study, the role of plasmonic metamaterials in light trapping photovoltaics for inorganic semiconducting materials by a simple and low cost spray pyrolysis technique has been studied. The plasmonic metamaterials thin film has been fabricated by depositing chemically converted graphene (CCG) onto TiO2-Ag nanoparticles which has a low resistivity and a low electron-hole recombination probability. The localized surface plasmon resonance at the metal-dielectric interface for the Ag nanoparticles has been observed at 403 nm after depositing chemical converted graphene (CCG) on the TiO2-Ag thin film. The results suggest that the stacking order of the CCG/TiO2/Ag plasmonic metamaterials samples did not change the band gap of TiO2 while it changed the conductivity of the film. Thus the diffusion of the noble metals in the glass and TiO2 matrices based thin films can trap the light of a particular wavelength by mean of plasmonic resonance and may be useful for superior photovoltaic and optoelectronic applications.

An Operationally Simple Method for Separating the Rare-Earth Elements Neodymium and Dysprosium.

Science.gov (United States)

Bogart, Justin A; Lippincott, Connor A; Carroll, Patrick J; Schelter, Eric J

2015-07-06

Rare-earth metals are critical components of electronic materials and permanent magnets. Recycling of consumer materials is a promising new source of rare earths. To incentivize recycling there is a clear need for simple methods for targeted separations of mixtures of rare-earth metal salts. Metal complexes of a tripodal nitroxide ligand [{(2-(t) BuNO)C6 H4 CH2 }3 N](3-) (TriNOx(3-) ), feature a size-sensitive aperture formed of its three η(2) -(N,O) ligand arms. Exposure of metal cations in the aperture induces a self-associative equilibrium comprising [M(TriNOx)thf]/ [M(TriNOx)]2 (M=rare-earth metal). Differences in the equilibrium constants (Keq ) for early and late metals enables simple Nd/Dy separations through leaching with a separation ratio SNd/Dy =359. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Slope stability and bearing capacity of landfills and simple on-site test methods.

Science.gov (United States)

Yamawaki, Atsushi; Doi, Yoichi; Omine, Kiyoshi

2017-07-01

This study discusses strength characteristics (slope stability, bearing capacity, etc.) of waste landfills through on-site tests that were carried out at 29 locations in 19 sites in Japan and three other countries, and proposes simple methods to test and assess the mechanical strength of landfills on site. Also, the possibility of using a landfill site was investigated by a full-scale eccentric loading test. As a result of this, landfills containing more than about 10 cm long plastics or other fibrous materials were found to be resilient and hard to yield. An on-site full scale test proved that no differential settlement occurs. The repose angle test proposed as a simple on-site test method has been confirmed to be a good indicator for slope stability assessment. The repose angle test suggested that landfills which have high, near-saturation water content have considerably poorer slope stability. The results of our repose angle test and the impact acceleration test were related to the internal friction angle and the cohesion, respectively. In addition to this, it was found that the air pore volume ratio measured by an on-site air pore volume ratio test is likely to be related to various strength parameters.

Simple time-saving method for iron determination based on fluorescence quenching of an azaflavanon-3-ol compound.

Science.gov (United States)

Başoğlu, Aysel; Tosun, Gonca; Ocak, Miraç; Alp, Hakan; Yaylı, Nurettin; Ocak, Ümmühan

2015-03-18

A simple and time-saving spectrofluorometric method developed using an azaflavanon-3-ol compound was used for the determination of iron in various food samples. Nitric acid and hydrogen peroxide were used for digestion of samples in a closed microwave system. The method was validated by analyzing two certified reference materials (CRM-SA-C Sandy Soil C and Mixed Polish Herbs INCT-MPH-2). Measurements were carried out using a modified standard addition method. The standard addition graph was linear until 21.6 mg/L in the determination of iron(III). Detection and quantification limits were 0.81 and 2.4 mg/L, respectively. Satisfactory accuracy was obtained for spinach, dill, mint, purslane, rocket, red lentils, dry beans, and two iron medicinal tablets. High recoveries were found for streamwater samples fortified at three different concentrations. The method is simple, time-saving, cost-effective, and suitable for the determination of the iron content of foods.

Simple method of generating and distributing frequency-entangled qudits

Science.gov (United States)

Jin, Rui-Bo; Shimizu, Ryosuke; Fujiwara, Mikio; Takeoka, Masahiro; Wakabayashi, Ryota; Yamashita, Taro; Miki, Shigehito; Terai, Hirotaka; Gerrits, Thomas; Sasaki, Masahide

2016-11-01

High-dimensional, frequency-entangled photonic quantum bits (qudits for d-dimension) are promising resources for quantum information processing in an optical fiber network and can also be used to improve channel capacity and security for quantum communication. However, up to now, it is still challenging to prepare high-dimensional frequency-entangled qudits in experiments, due to technical limitations. Here we propose and experimentally implement a novel method for a simple generation of frequency-entangled qudts with d\\gt 10 without the use of any spectral filters or cavities. The generated state is distributed over 15 km in total length. This scheme combines the technique of spectral engineering of biphotons generated by spontaneous parametric down-conversion and the technique of spectrally resolved Hong-Ou-Mandel interference. Our frequency-entangled qudits will enable quantum cryptographic experiments with enhanced performances. This distribution of distinct entangled frequency modes may also be useful for improved metrology, quantum remote synchronization, as well as for fundamental test of stronger violation of local realism.

A simple method to estimate radiation interception by nursery stock conifers: a case study of eastern white cedar

International Nuclear Information System (INIS)

Pronk, A.A.; Goudriaan, J.; Stilma, E.; Challa, H.

2003-01-01

A simple method was developed to estimate the fraction radiation intercepted by small eastern white cedar plants (Thuja occidentalis ‘Brabant’). The method, which describes the crop canopy as rows of cuboids, was compared with methods used for estimating radiation interception by crops with homogeneous canopies and crops grown in rows. The extinction coefficient k was determined at different plant arrangements and an average k-value of 0.48 ± 0.03 (R 2 = 0.89) was used in the calculations. Effects of changing plant characteristics and inter- and intra-row plant distances were explored. The fraction radiation intercepted that was estimated with the method for rows of cuboids was up to 20% and for row crops up to 8% lower than estimated with the method for homogeneous canopies at low plant densities and a LAI of 1. The fraction radiation intercepted by small plants of Thuja occidentalis ‘Brabant’ was best estimated by the simple method described in this paper

Effect of drying methods on the chemical composition of three ...

African Journals Online (AJOL)

Three methods of drying (oven, sun and smoke) were used to dry Bonga spp., Sardinella spp. and Heterotis niloticus. The physico-chemical and minerals contents of the sample were determined using standard methods. Oven dried H. niloticus recorded the highest (16.42%) moisture content while the least moisture content ...

Characterizations on the microstructures of LiMn2O4 prepared by a simple soft-chemical technique

International Nuclear Information System (INIS)

Wei Yingjin; Kim, Kwang Bum; Chen Gang; Park, Chul W.

2008-01-01

LiMn 2 O 4 powders were prepared by a simple soft-chemical technique at different temperatures. X-ray diffraction and thermogravimetric analysis suggested that the material prepared at 800 deg. C was stoichiometric LiMn 2 O 4 , whereas those prepared at 600 and 700 deg. C were Li[Mn 0.77 3+ Mn 1.23 4+ ]O 4.115 and Li[Mn 0.85 3+ Mn 1.15 4+ ]O 4.075 . Several typical XRD peaks of the compounds were investigated with an aim to elucidate (i) the Li immigration to the 16d octahedral sites, (ii) the partial tetragonal phase transition of the material and (iii) the mean coherent domain size and microstrain. SEM study showed that the particle size of the materials increased with heating temperature. The activation energy for the material particle growth was determined as 30.4 kJ mol -1

Method for innovative synthesis-design of chemical process flowsheets

DEFF Research Database (Denmark)

Kumar Tula, Anjan; Gani, Rafiqul

Chemical process synthesis-design involve the identification of the processing route to reach a desired product from a specified set of raw materials, design of the operations involved in the processing route, the calculations of utility requirements, the calculations of waste and emission...... to the surrounding and many more. Different methods (knowledge-based [1], mathematical programming [2], hybrid, etc.) have been proposed and are also currently employed to solve these synthesis-design problems. D’ Anterroches [3] proposed a group contribution based approach to solve the synthesis-design problem...... of chemical processes, where, chemical process flowsheets could be synthesized in the same way as atoms or groups of atoms are synthesized to form molecules in computer aided molecular design (CAMD) techniques [4]. That, from a library of building blocks (functional process-groups) and a set of rules to join...

A simple method to take urethral sutures for neobladder reconstruction and radical prostatectomy

Directory of Open Access Journals (Sweden)

B Satheesan

2007-01-01

Full Text Available For the reconstruction of urethra-vesical anastamosis after radical prostatectomy and for neobladder reconstruction, taking adequate sutures to include the urethral mucosa is vital. Due to the retraction of the urethra and unfriendly pelvis, the process of taking satisfactory urethral sutures may be laborious. Here, we describe a simple method by which we could overcome similar technical problems during surgery using Foley catheter as the guide for the suture.

Emergency First Responders' Experience with Colorimetric Detection Methods

Energy Technology Data Exchange (ETDEWEB)

Sandra L. Fox; Keith A. Daum; Carla J. Miller; Marnie M. Cortez

2007-10-01

Nationwide, first responders from state and federal support teams respond to hazardous materials incidents, industrial chemical spills, and potential weapons of mass destruction (WMD) attacks. Although first responders have sophisticated chemical, biological, radiological, and explosive detectors available for assessment of the incident scene, simple colorimetric detectors have a role in response actions. The large number of colorimetric chemical detection methods available on the market can make the selection of the proper methods difficult. Although each detector has unique aspects to provide qualitative or quantitative data about the unknown chemicals present, not all detectors provide consistent, accurate, and reliable results. Included here, in a consumer-report-style format, we provide “boots on the ground” information directly from first responders about how well colorimetric chemical detection methods meet their needs in the field and how they procure these methods.

Simple emittance measurement of negative hydrogen ion beam using pepper-pot method

International Nuclear Information System (INIS)

Hamabe, M.; Tsumori, K.; Takeiri, Y.; Kaneko, O.; Asano, E.; Kawamoto, T.; Kuroda, T.; Guharay, S.K.

1997-01-01

A simple apparatus for emittance measurement using pepper-pot method is developed. The pepper-pot patterns are directly exposed and recorded on a Kapton foil. Using this apparatus, emittance was measured in the case of the negative hydrogen (H - ) beam from the large negative ion source, which is the 1/3 scaled test device for the negative-ion-based neutral beam injection (N-NBI) on the Large Helical Device (LHD). As the consequence of the first trial, the 95% normalized emittance value is measured as 0.59 mm mrad. (author)

Simple emittance measurement of negative hydrogen ion beam using pepper-pot method

Energy Technology Data Exchange (ETDEWEB)

Hamabe, M.; Tsumori, K.; Takeiri, Y.; Kaneko, O.; Asano, E.; Kawamoto, T.; Kuroda, T. [National Inst. for Fusion Science, Nagoya (Japan); Guharay, S.K.

1997-02-01

A simple apparatus for emittance measurement using pepper-pot method is developed. The pepper-pot patterns are directly exposed and recorded on a Kapton foil. Using this apparatus, emittance was measured in the case of the negative hydrogen (H{sup -}) beam from the large negative ion source, which is the 1/3 scaled test device for the negative-ion-based neutral beam injection (N-NBI) on the Large Helical Device (LHD). As the consequence of the first trial, the 95% normalized emittance value is measured as 0.59 mm mrad. (author)

Fabricating Super-hydrophobic Polydimethylsiloxane Surfaces by a Simple Filler-Dissolved Process

Science.gov (United States)

Lin, Yung-Tsan; Chou, Jung-Hua

2010-12-01

The self-cleaning effect of super-hydrophobic surfaces has attracted the attention of researchers. Typical ways of manufacturing super-hydrophobic surfaces include the use of either dedicated equipment or a complex chemical process. In this study, a simple innovative filler-dissolved method is developed using mainly powder salt and rinsing to form hydrophobic surfaces. This method can produce large super-hydrophobic surfaces with porous and micro rib surface structures. It can also be applied to curved surfaces, including flexible membranes. The contact angle of the manufactured artificial hydrophobic surface is about 160°. Furthermore, water droplets roll off the surface readily at a sliding angle of less than 5°, resembling the nonwetting lotus like effect.

A simple method for plasma total vitamin C analysis suitable for routine clinical laboratory use.

Science.gov (United States)

Robitaille, Line; Hoffer, L John

2016-04-21

In-hospital hypovitaminosis C is highly prevalent but almost completely unrecognized. Medical awareness of this potentially important disorder is hindered by the inability of most hospital laboratories to determine plasma vitamin C concentrations. The availability of a simple, reliable method for analyzing plasma vitamin C could increase opportunities for routine plasma vitamin C analysis in clinical medicine. Plasma vitamin C can be analyzed by high performance liquid chromatography (HPLC) with electrochemical (EC) or ultraviolet (UV) light detection. We modified existing UV-HPLC methods for plasma total vitamin C analysis (the sum of ascorbic and dehydroascorbic acid) to develop a simple, constant-low-pH sample reduction procedure followed by isocratic reverse-phase HPLC separation using a purely aqueous low-pH non-buffered mobile phase. Although EC-HPLC is widely recommended over UV-HPLC for plasma total vitamin C analysis, the two methods have never been directly compared. We formally compared the simplified UV-HPLC method with EC-HPLC in 80 consecutive clinical samples. The simplified UV-HPLC method was less expensive, easier to set up, required fewer reagents and no pH adjustments, and demonstrated greater sample stability than many existing methods for plasma vitamin C analysis. When compared with the gold-standard EC-HPLC method in 80 consecutive clinical samples exhibiting a wide range of plasma vitamin C concentrations, it performed equivalently. The easy set up, simplicity and sensitivity of the plasma vitamin C analysis method described here could make it practical in a normally equipped hospital laboratory. Unlike any prior UV-HPLC method for plasma total vitamin C analysis, it was rigorously compared with the gold-standard EC-HPLC method and performed equivalently. Adoption of this method could increase the availability of plasma vitamin C analysis in clinical medicine.

Virtual screening methods as tools for drug lead discovery from large chemical libraries.

Science.gov (United States)

Ma, X H; Zhu, F; Liu, X; Shi, Z; Zhang, J X; Yang, S Y; Wei, Y Q; Chen, Y Z

2012-01-01

Virtual screening methods have been developed and explored as useful tools for searching drug lead compounds from chemical libraries, including large libraries that have become publically available. In this review, we discussed the new developments in exploring virtual screening methods for enhanced performance in searching large chemical libraries, their applications in screening libraries of ~ 1 million or more compounds in the last five years, the difficulties in their applications, and the strategies for further improving these methods.

Development of Test Method for Simple Shear and Prediction of Hardening Behavior Considering the Branchings Effect

International Nuclear Information System (INIS)

Kim, Dongwook; Bang, Sungsik; Kim, Minsoo; Lee, Hyungyil; Kim, Naksoo

2013-01-01

In this study we establish a process to predict hardening behavior considering the Branchings effect for zircaloy-4 sheets. When a metal is compressed after tension in forming, the yield strength decreases. For this reason, the Branchings effect should be considered in FE simulations of spring-back. We suggested a suitable specimen size and a method for determining the optimum tightening torque for simple shear tests. Shear stress-strain curves are obtained for five materials. We developed a method to convert the shear load-displacement curve to the effective stress-strain curve with Fea. We simulated the simple shear forward/reverse test using the combined isotropic/kinematic hardening model. We also investigated the change of the load-displacement curve by varying the hardening coefficients. We determined the hardening coefficients so that they follow the hardening behavior of zircaloy-4 in experiments

Development of Test Method for Simple Shear and Prediction of Hardening Behavior Considering the Branchings Effect

Energy Technology Data Exchange (ETDEWEB)

Kim, Dongwook; Bang, Sungsik; Kim, Minsoo; Lee, Hyungyil; Kim, Naksoo [Sogang Univ., Seoul (Korea, Republic of)

2013-10-15

In this study we establish a process to predict hardening behavior considering the Branchings effect for zircaloy-4 sheets. When a metal is compressed after tension in forming, the yield strength decreases. For this reason, the Branchings effect should be considered in FE simulations of spring-back. We suggested a suitable specimen size and a method for determining the optimum tightening torque for simple shear tests. Shear stress-strain curves are obtained for five materials. We developed a method to convert the shear load-displacement curve to the effective stress-strain curve with Fea. We simulated the simple shear forward/reverse test using the combined isotropic/kinematic hardening model. We also investigated the change of the load-displacement curve by varying the hardening coefficients. We determined the hardening coefficients so that they follow the hardening behavior of zircaloy-4 in experiments.

Slow manifolds in chemical kinetics

International Nuclear Information System (INIS)

Shahzad, M.; Haq, I. U.; Sultan, F.; Wahab, A.; Faizullah, F.; Rahman, G. U.

2016-01-01

Modelling the chemical system, especially for complex and higher dimensional problems, gives an easy way to handle the ongoing reaction process with respect to time. Here, we will consider some of the newly developed computational methods commonly used for model reductions in a chemical reaction. An effective (simple) method is planned to measure the low dimensional manifold, which reduces the higher dimensional system in such a way that it may not affect the precision of the whole mechanism. The phase flow of the solution trajectories near the equilibrium point is observed while the initial approximation is measured with the spectral quasi equilibrium manifold, which starts from the equilibrium point. To make it an invariant curve, the approximated curve is first refined a certain number of times using the method of invariant grids. The other way of getting the reduced data in the low dimensional manifold is possible through the intrinsic low dimensional manifold. Then, we compare these two invariant curves given by both the methods. Finally, the idea is extended to the higher dimensional manifold, where more number of progress variables will be added. (author)

Comparison of electro and chemical cautery in the treatment of anterior epistaxis.

Science.gov (United States)

Toner, J G; Walby, A P

1990-08-01

In the ENT Department of the Royal Victoria Hospital, Belfast, the impression (supported only by anecdotes) was that electro-cautery was superior to chemical cautery in the treatment of simple anterior epistaxis. Since no evaluation of the relative merits of electro and chemical cautery has been reported, a prospective randomized study was conducted to assess the effectiveness of electro-cautery and cautery with silver nitrate. The results of the study showed that there was no statistically significant difference between the two methods in either controlling the epistaxis or in the incidence of complications. It is concluded that since cautery with a silver nitrate tipped applicator is simpler, and of equal effectiveness, it would appear to be the treatment of choice for simple anterior epistaxis.

Linearized self-consistent quasiparticle GW method: Application to semiconductors and simple metals

International Nuclear Information System (INIS)

Kutepov, A. L.

2017-01-01

We present a code implementing the linearized self-consistent quasiparticle GW method (QSGW) in the LAPW basis. Our approach is based on the linearization of the self-energy around zero frequency which differs it from the existing implementations of the QSGW method. The linearization allows us to use Matsubara frequencies instead of working on the real axis. This results in efficiency gains by switching to the imaginary time representation in the same way as in the space time method. The all electron LAPW basis set eliminates the need for pseudopotentials. We discuss the advantages of our approach, such as its N 3 scaling with the system size N, as well as its shortcomings. We apply our approach to study the electronic properties of selected semiconductors, insulators, and simple metals and show that our code produces the results very close to the previously published QSGW data. Our implementation is a good platform for further many body diagrammatic resummations such as the vertex-corrected GW approach and the GW+DMFT method.

A identification system for chemical warfare agents with PGNAA method

International Nuclear Information System (INIS)

Wang Bairong; Yin Guanghua; Yang Zhongping

2006-01-01

The principle and the experimental commanding of Chemical warfare Agents Identification with PGNAA method are discussed in this paper. The choosing of Detector, neutron source and the data processing method are detailed. Finally, a set of experimental instruments composed of Cf-232 and BGO detector is developed based on the theory discussed above. (authors)

An operationally simple method for separating the rare-earth elements neodymium and dysprosium

Energy Technology Data Exchange (ETDEWEB)

Bogart, Justin A.; Lippincott, Connor A.; Carroll, Patrick J.; Schelter, Eric J. [Department of Chemistry, University of Pennsylvania, Philadelphia, PA (United States)

2015-07-06

Rare-earth metals are critical components of electronic materials and permanent magnets. Recycling of consumer materials is a promising new source of rare earths. To incentivize recycling there is a clear need for simple methods for targeted separations of mixtures of rare-earth metal salts. Metal complexes of a tripodal nitroxide ligand [{(2-"tBuNO)C_6H_4CH_2}{sub 3}N]{sup 3-} (TriNOx{sup 3-}), feature a size-sensitive aperture formed of its three η{sup 2}-(N,O) ligand arms. Exposure of metal cations in the aperture induces a self-associative equilibrium comprising [M(TriNOx)thf]/[M(TriNOx)]{sub 2} (M=rare-earth metal). Differences in the equilibrium constants (K{sub eq}) for early and late metals enables simple Nd/Dy separations through leaching with a separation ratio S{sub Nd/Dy}=359. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Simple method for functionalization of silica with alkyl silane and organic ligands

Directory of Open Access Journals (Sweden)

Kasim Mohammed Hello

2018-06-01

Full Text Available 3–(chloropropyltriethoxysilane (CPTES with imidazole and sodium silicate from rice husk ash (RHA successfully reacted within a short time in one–pot synthesis in purely homogenous method. A similar procedure was used for the immobilization of melamine and saccharine to demonstrate a generally applicable method. No reflux was needed, and a green solvent was used as the reaction medium. The surface areas of the prepared materials were very high compared with the materials which have similar structure prepared by the traditional method. The TGA/DTA confirmed that all the materials were highly stable. The FT-IR shows that all expected the functional groups were present. The HRTEM showed that the materials had ordered mesoporous straight-channels which were like the MCM-41. The synthesis procedure is simple, repeatable with different organic ligands and does not require toxic solvents or multiple steps with high products yield. Keywords: Rice husk ash, MCM-41, Imidazole, Melamine, Saccharine

A simple orbit-attitude coupled modelling method for large solar power satellites

Science.gov (United States)

Li, Qingjun; Wang, Bo; Deng, Zichen; Ouyang, Huajiang; Wei, Yi

2018-04-01

A simple modelling method is proposed to study the orbit-attitude coupled dynamics of large solar power satellites based on natural coordinate formulation. The generalized coordinates are composed of Cartesian coordinates of two points and Cartesian components of two unitary vectors instead of Euler angles and angular velocities, which is the reason for its simplicity. Firstly, in order to develop natural coordinate formulation to take gravitational force and gravity gradient torque of a rigid body into account, Taylor series expansion is adopted to approximate the gravitational potential energy. The equations of motion are constructed through constrained Hamilton's equations. Then, an energy- and constraint-conserving algorithm is presented to solve the differential-algebraic equations. Finally, the proposed method is applied to simulate the orbit-attitude coupled dynamics and control of a large solar power satellite considering gravity gradient torque and solar radiation pressure. This method is also applicable to dynamic modelling of other rigid multibody aerospace systems.

Control of Solar Power Plants Connected Grid with Simple Calculation Method on Residential Homes

Science.gov (United States)

Kananda, Kiki; Nazir, Refdinal

2017-12-01

One of the most compatible renewable energy in all regions to apply is solar energy. Solar power plants can be built connected to existing or stand-alone power grids. In assisting the residential electricity in which there is a power grid, then a small scale solar energy power plants is very appropriate. However, the general constraint of solar energy power plants is still low in terms of efficiency. Therefore, this study will explain how to control the power of solar power plants more optimally, which is expected to reactive power to zero to raise efficiency. This is a continuation of previous research using Newton Rapshon control method. In this study we introduce a simple method by using ordinary mathematical calculations of solar-related equations. In this model, 10 PV modules type of ND T060M1 with a 60 Wp capacity are used. The calculations performed using MATLAB Simulink provide excellent value. For PCC voltage values obtained a stable quantity of approximately 220 V. At a maximum irradiation condition of 1000 W / m2, the reactive power value of Q solar generating system maximum 20.48 Var and maximum active power of 417.5 W. In the condition of lower irradiation, value of reactive power Q almost close to zero 0.77Var. This simple mathematical method can provide excellent quality control power values.

X-ray methods for the chemical characterization of atmospheric aerosols

International Nuclear Information System (INIS)

Jaklevic, J.M.; Thompson, A.C.

1981-05-01

The development and use of several x-ray methods for the chemical characterization of atmospherical aerosol particulate samples are described. These methods are based on the emission, absorption, and scattering of x-ray photons with emphasis on the optimization for the non-destructive analysis of dilute specimens. Techniques discussed include photon induced energy dispersive x-ray fluorescence, extended x-ray absorption fine structure spectroscopy using synchrotron radiation and high-rate x-ray powder diffractometry using a position-sensitive gas proportional counter. These x-ray analysis methods were applied to the measurement of the chemical compositions of size-segregated aerosol particulate samples obtained with dichotomous samplers. The advantages of the various methods for use in such measurements are described and results are presented. In many cases, the complementary nature of the analytical information obtained from the various measurements is an important factor in the characterization of the sample. For example, the multiple elemental analyses obtained from x-ray fluorescence can be used as a cross check on the major compounds observed by powder diffraction

A simple and efficient method for assembling TALE protein based on plasmid library.

Science.gov (United States)

Zhang, Zhiqiang; Li, Duo; Xu, Huarong; Xin, Ying; Zhang, Tingting; Ma, Lixia; Wang, Xin; Chen, Zhilong; Zhang, Zhiying

2013-01-01

DNA binding domain of the transcription activator-like effectors (TALEs) from Xanthomonas sp. consists of tandem repeats that can be rearranged according to a simple cipher to target new DNA sequences with high DNA-binding specificity. This technology has been successfully applied in varieties of species for genome engineering. However, assembling long TALE tandem repeats remains a big challenge precluding wide use of this technology. Although several new methodologies for efficiently assembling TALE repeats have been recently reported, all of them require either sophisticated facilities or skilled technicians to carry them out. Here, we described a simple and efficient method for generating customized TALE nucleases (TALENs) and TALE transcription factors (TALE-TFs) based on TALE repeat tetramer library. A tetramer library consisting of 256 tetramers covers all possible combinations of 4 base pairs. A set of unique primers was designed for amplification of these tetramers. PCR products were assembled by one step of digestion/ligation reaction. 12 TALE constructs including 4 TALEN pairs targeted to mouse Gt(ROSA)26Sor gene and mouse Mstn gene sequences as well as 4 TALE-TF constructs targeted to mouse Oct4, c-Myc, Klf4 and Sox2 gene promoter sequences were generated by using our method. The construction routines took 3 days and parallel constructions were available. The rate of positive clones during colony PCR verification was 64% on average. Sequencing results suggested that all TALE constructs were performed with high successful rate. This is a rapid and cost-efficient method using the most common enzymes and facilities with a high success rate.

A simple and accurate method for bidimensional position read-out of parallel plate avalanche counters

International Nuclear Information System (INIS)

Breskin, A.; Zwang, N.

1977-01-01

A simple method for bidimensional position read-out of Parallel Plate Avalanche counters (PPAC) has been developed, using the induced charge technique. An accuracy better than 0.5 mm (FWHM) has been achieved for both coordinates with 5.5. MeV α-particles at gas pressures of 10-40 torr. (author)

A simple method for labelling proteins with 211At via diazotized aromatic diamine

International Nuclear Information System (INIS)

Wunderlich, G.; Franke, W.-G.; Fischer, S.; Dreyer, R.

1987-01-01

A simple and rapid method for labelling proteins with 211 At by means of a 1,4-diaminobenzene link is described. This link is transformed into the diazonium salt and subsequently reactions of both 211 At and proteins with the diazonium salt take place simultaneously. For possibly high yields of astatized protein an appropriate temperature of 273 K was found. The results demonstrate the difference between the reaction mechanisms of iodine and astatine with proteins. (author)

Use of simple finite elements for mechanical systems impact analysis based on stereomechanics, stress wave propagation, and energy method approaches

International Nuclear Information System (INIS)

McCoy, Michael L.; Moradi, Rasoul; Lankarani, Hamid M.

2011-01-01

This paper examines the effectiveness of analyzing impact events in mechanical systems for design purposes using simple or low ordered finite elements. Traditional impact dynamics analyses of mechanical systems namely stereomechanics, energy method, stress-wave propagation and contact mechanics approaches are limited to very simplified geometries and provide basic analyses in making predictions and understanding the dominant features of the impact in a mechanical system. In engineering practice, impacted systems present a complexity of geometry, stiffness, mass distributions, contact areas and impact angles that are impossible to analyze and design with the traditional impact dynamics methods. In real cases, the effective tool is the finite element (FE) method. The high-end FEA codes though may be not available for typical engineer/designer. This paper provides information on whether impact events of mechanical systems can be successfully modeled using simple or low-order finite elements. FEA models using simple elements are benchmarked against theoretical impact problems and published experimental impact results. As a case study, an FE model using simple plastic beam elements is further tested to predict stresses and deflections in an experimental structural impact

Chemical synthesis of Cd-free wide band gap materials for solar cells

Energy Technology Data Exchange (ETDEWEB)

Sankapal, B.R.; Sartale, S.D.; Ennaoui, A. [Hahn-Meitner-Institut, Berlin (Germany). Department of Solar Energy Research; Lokhande, C.D. [Shivaji University, Kolhapur (India). Department of Physics

2004-07-01

Chemical methods are nowadays very attractive, since they are relatively simple, low cost and convenient for larger area deposition of thin films. In this paper, we outline our work related to the synthesis and characterization of some wide band gap semiconducting material thin films prepared by using solution methods, namely, chemical bath deposition and successive ionic layer adsorption and reaction (SILAR). The optimum preparative parameters are given and respective structural, surface morphological, compositional, optical, and electrical properties are described. Some materials we used in solar cells as buffer layers and achieved remarkable results, which are summarized. (author)

SIMPLE METHOD FOR THE EXTRACTION OF PHOTOPIGMENTS AND MYCOSPORINE-LIKE AMINO ACIDS (MAAS) FROM SYMBIODINIUM SPP.

Science.gov (United States)

Numerous extraction methods have been developed and used in the quantitation of both photopigments and mycosporine amino acids (MAAs) found in Symbiodinium sp. and zooanthellate metazoans. We have development of a simple, mild extraction procedure using methanol, which when coupl...

A Simple Method to Determine the "R" or "S" Configuration of Molecules with an Axis of Chirality

Science.gov (United States)

Wang, Cunde; Wu, Weiming

2011-01-01

A simple method for the "R" or "S" designation of molecules with an axis of chirality is described. The method involves projection of the substituents along the chiral axis, utilizes the Cahn-Ingold-Prelog sequence rules in assigning priority to the substituents, is easy to use, and has broad applicability. (Contains 5 figures.)

Method of chemical decontamination of stainless steel

International Nuclear Information System (INIS)

Onuma, Tsutomu; Akimoto, Hidetoshi.

1989-01-01

The present invention concerns a decontamination method of chemically decontaminating radioactive metal wastes of passivated stainless steels to a radioactivity level identical with usual wastes, in which the amount of oxidizable metal salts used is decreased. Metal wastes of stainless steels contaminated at their surface with radioactive materials are immersed in a sulfuric acid solution. In this case, a voltage is applied for a certain period of time so that the potential of the stainless steels comes to an active region. Then, oxidizable metal salt (tetravalent cerium) is added into the sulfuric acid solution. According to this method, since most of radioactive materials are removed in the immersing step to the sulfuric acid solution, the amount of the tetravalent cerium used is as less as 1/700 and the decontamination time is as short as 1/4 as compared with those in the conventional method. (K.M.)

Characterization of Olive Oil by Ultrasonic and Physico-chemical Methods

Science.gov (United States)

Alouache, B.; Khechena, F. K.; Lecheb, F.; Boutkedjirt, T.

Olive oil excels by its nutritional and medicinal benefits. It can be consumed without any treatment. However, its quality can be altered by inadequate storage conditions or if it is mixed with other kinds of oils. The objective of this work is to demonstrate the ability of ultrasonic methods to characterize and control olive oil quality. By using of a transducer of 2.25 MHz nominal frequency, in pulse echo mode, ultrasonic parameters, such as propagation velocity and attenuation,have been measured for pure olive oil and for its mixtures with sunflower oil at different proportions. Mechanical properties, such as density and viscosity, have also been determined. The results of ultrasonic measurements are consistent with those obtained by physico-chemical methods, such as rancidity degree, acid index, UV specific extinction coefficient and viscosity. They show that the ultrasonic method allows to distinguish between mixtures at different proportions. The study allows concluding that ultrasound techniques can be considered as a useful complement to existing physico-chemical analysis techniques.

Methods of chemical and phase composition analysis of gallstones

Science.gov (United States)

Suvorova, E. I.; Pantushev, V. V.; Voloshin, A. E.

2017-11-01

This review presents the instrumental methods used for chemical and phase composition investigation of gallstones. A great body of data has been collected in the literature on the presence of elements and their concentrations, obtained by fluorescence microscopy, X-ray fluorescence spectroscopy, neutron activation analysis, proton (particle) induced X-ray emission, atomic absorption spectroscopy, high-resolution gamma-ray spectrometry, electron paramagnetic resonance. Structural methods—powder X-ray diffraction, infrared spectroscopy, Raman spectroscopy—provide information about organic and inorganic phases in gallstones. Stone morphology was studied at the macrolevel with optical microscopy. Results obtained by analytical scanning and transmission electron microscopy with X-ray energy dispersive spectrometry are discussed. The chemical composition and structure of gallstones determine the strategy of removing stone from the body and treatment of patients: surgery or dissolution in the body. Therefore one chapter of the review describes the potential of dissolution methods. Early diagnosis and appropriate treatment of the disease depend on the development of clinical methods for in vivo investigation, which gave grounds to present the main characteristics and potential of ultrasonography (ultrasound scanning), magnetic resonance imaging, and X-ray computed tomography.

Machine learning predictions of molecular properties: Accurate many-body potentials and nonlocality in chemical space

International Nuclear Information System (INIS)

Hansen, Katja; Biegler, Franziska; Ramakrishnan, Raghunathan; Pronobis, Wiktor; Lilienfeld, O. Anatole von; Müller, Klaus-Robert; Tkatchenko, Alexandre

2015-01-01

Simultaneously accurate and efficient prediction of molecular properties throughout chemical compound space is a critical ingredient toward rational compound design in chemical and pharmaceutical industries. Aiming toward this goal, we develop and apply a systematic hierarchy of efficient empirical methods to estimate atomization and total energies of molecules. These methods range from a simple sum over atoms, to addition of bond energies, to pairwise interatomic force fields, reaching to the more sophisticated machine learning approaches that are capable of describing collective interactions between many atoms or bonds. In the case of equilibrium molecular geometries, even simple pairwise force fields demonstrate prediction accuracy comparable to benchmark energies calculated using density functional theory with hybrid exchange-correlation functionals; however, accounting for the collective many-body interactions proves to be essential for approaching the 'holy grail' of chemical accuracy of 1 kcal/mol for both equilibrium and out-of-equilibrium geometries. This remarkable accuracy is achieved by a vectorized representation of molecules (so-called Bag of Bonds model) that exhibits strong nonlocality in chemical space. The same representation allows us to predict accurate electronic properties of molecules, such as their polarizability and molecular frontier orbital energies

A simple gel electrophoresis method for separating polyhedral gold nanoparticles

Science.gov (United States)

Kim, Suhee; Lee, Hye Jin

2015-07-01

In this paper, a simple approach to separate differently shaped and sized polyhedral gold nanoparticles (NPs) within colloidal solutions via gel electrophoresis is described. Gel running parameters for separating efficiently gold NPs including gel composition, added surfactant types and applied voltage were investigated. The plasmonic properties and physical structure of the separated NPs extracted from the gel matrix were then investigated using transmission electron microscopy (TEM) and UV-vis spectrophotometry respectively. Data analysis revealed that gel electrophoresis conditions of a 1.5 % agarose gel with 0.1 % sodium dodecyl sulfate (SDS) surfactant under an applied voltage of 100 V resulted in the selective isolation of ~ 50 nm polyhedral shaped gold nanoparticles. Further efforts are underway to apply the method to purify biomolecule-conjugated polyhedral Au NPs that can be readily used for NP-enhanced biosensing platforms.

A simple method for the prevention of endometrial autolysis in hysterectomy specimens.

Science.gov (United States)

Houghton, J P; Roddy, S; Carroll, S; McCluggage, W G

2004-03-01

Uteri are among the most common surgical pathology specimens. Assessment of the endometrium is often difficult because of pronounced tissue autolysis. This study describes a simple method to prevent endometrial autolysis and aid in interpretation of the endometrium. Sixty uteri were injected with formalin using a needle and syringe directed alongside a probe, which was inserted through the external cervical os into the endometrial cavity. Injection was performed on the same day as removal of the uterus. As controls, 60 uteri that were not injected with formalin were examined. The degree of endometrial autolysis was assessed on a four point scale (0-3), with a score of 0 representing no or minimal autolysis and a score of 3 representing extensive autolysis, such that histological interpretation of the endometrium was impossible. In the injected group, the number of cases with scores of 0, 1, 2, and 3 was 42, 13, four, and one, respectively. The corresponding values for the control group were 17, 23, eight, and 12, respectively. This was highly significant (p autolysis in uteri injected with formalin. The use of this simple procedure should be encouraged in hysterectomy specimens.

A comparison of partial order technique with three methods of multi-criteria analysis for ranking of chemical substances.

Science.gov (United States)

Lerche, Dorte; Brüggemann, Rainer; Sørensen, Peter; Carlsen, Lars; Nielsen, Ole John

2002-01-01

An alternative to the often cumbersome and time-consuming risk assessments of chemical substances could be more reliable and advanced priority setting methods. An elaboration of the simple scoring methods is provided by Hasse Diagram Technique (HDT) and/or Multi-Criteria Analysis (MCA). The present study provides an in depth evaluation of HDT relative to three MCA techniques. The new and main methodological step in the comparison is the use of probability concepts based on mathematical tools such as linear extensions of partially ordered sets and Monte Carlo simulations. A data set consisting of 12 High Production Volume Chemicals (HPVCs) is used for illustration. It is a paradigm in this investigation to claim that the need of external input (often subjective weightings of criteria) should be minimized and that the transparency should be maximized in any multicriteria prioritisation. The study illustrates that the Hasse diagram technique (HDT) needs least external input, is most transparent and is least subjective. However, HDT has some weaknesses if there are criteria which exclude each other. Then weighting is needed. Multi-Criteria Analysis (i.e. Utility Function approach, PROMETHEE and concordance analysis) can deal with such mutual exclusions because their formalisms to quantify preferences allow participation e.g. weighting of criteria. Consequently MCA include more subjectivity and loose transparency. The recommendation which arises from this study is that the first step in decision making is to run HDT and as the second step possibly is to run one of the MCA algorithms.

Ga N nano wires and nano tubes growth by chemical vapor deposition method at different NH{sub 3} flow rate

Energy Technology Data Exchange (ETDEWEB)

Li, P.; Liu, Y.; Meng, X. [Wuhan University, School of Physics and Technology, Key Laboratory of Artificial Micro and Nanostructures of Ministry of Education, Wuhan 430072 (China)

2016-11-01

Ga N nano wires and nano tubes have been successfully synthesized via the simple chemical vapor deposition method. NH{sub 3} flow rate was found to be a crucial factor in the synthesis of different type of Ga N which affects the shape and the diameter of generated Ga N nano structures. X-ray diffraction confirms that Ga N nano wires grown on Si(111) substrate under 900 degrees Celsius and with NH{sub 3} flow rate of 50 sc cm presents the preferred orientation growth in the (002) direction. It is beneficial to the growth of nano structure through catalyst annealing. Transmission electron microscopy and scanning electron microscopy were used to measure the size and structures of the samples. (Author)

In Silico Prediction of Chemicals Binding to Aromatase with Machine Learning Methods.

Science.gov (United States)

Du, Hanwen; Cai, Yingchun; Yang, Hongbin; Zhang, Hongxiao; Xue, Yuhan; Liu, Guixia; Tang, Yun; Li, Weihua

2017-05-15

Environmental chemicals may affect endocrine systems through multiple mechanisms, one of which is via effects on aromatase (also known as CYP19A1), an enzyme critical for maintaining the normal balance of estrogens and androgens in the body. Therefore, rapid and efficient identification of aromatase-related endocrine disrupting chemicals (EDCs) is important for toxicology and environment risk assessment. In this study, on the basis of the Tox21 10K compound library, in silico classification models for predicting aromatase binders/nonbinders were constructed by machine learning methods. To improve the prediction ability of the models, a combined classifier (CC) strategy that combines different independent machine learning methods was adopted. Performances of the models were measured by test and external validation sets containing 1336 and 216 chemicals, respectively. The best model was obtained with the MACCS (Molecular Access System) fingerprint and CC method, which exhibited an accuracy of 0.84 for the test set and 0.91 for the external validation set. Additionally, several representative substructures for characterizing aromatase binders, such as ketone, lactone, and nitrogen-containing derivatives, were identified using information gain and substructure frequency analysis. Our study provided a systematic assessment of chemicals binding to aromatase. The built models can be helpful to rapidly identify potential EDCs targeting aromatase.

A Simple Method for Assessing Upper-Limb Force-Velocity Profile in Bench Press.

Science.gov (United States)

Rahmani, Abderrahmane; Samozino, Pierre; Morin, Jean-Benoit; Morel, Baptiste

2018-02-01

To analyze the reliability and validity of a field computation method based on easy-to-measure data to assess the mean force ([Formula: see text]) and velocity ([Formula: see text]) produced during a ballistic bench-press movement and to verify that the force-velocity profile (F-v) obtained with multiple loaded trials is accurately described. Twelve participants performed ballistic bench presses against various lifted mass from 30% to 70% of their body mass. For each trial, [Formula: see text] and [Formula: see text] were determined from an accelerometer (sampling rate 500 Hz; reference method) and a simple computation method based on upper-limb mass, barbell flight height, and push-off distance. These [Formula: see text] and [Formula: see text] data were used to establish the F-v relationship for each individual and method. A strong to almost perfect reliability was observed between the 2 trials (ICC > .90 for [Formula: see text] and .80 for [Formula: see text], CV%  .80, P push-off distance).

Radiation-chemical concepts applied to the wholesomeness evaluation of irradiated foods

International Nuclear Information System (INIS)

Basson, R.A.

1977-06-01

Food irradiation has anomalously been classified as a food additive rather than as a processing method. The justification for this is that chemical changes take place during the process. However, most foodstuffs consist of a large number of constituents, most of which are present in small concentrations. As a result, the amounts of radiolysis products which may be formed are far too low for identification and measurement, even by conventional analytical methods. Radiation-chemical knowledge is applied to determine the probable nature and concentration of reaction products produced in fruits. Fruits consist mainly of water and carbohydrates, with small amounts of protein, fat, inorganic material and vitamins as 'contaminants'. The real situation is exceedingly complex, but, using this simple model as a first approximation, predictions which may be verified in a relatively simple experimental scheme are made on the radiation stability of a typical fruit. Calculations using known radiation-chemical data show that, in the case of the mango, only carbohydrates are present in sufficient concentration and of sufficient sensitivity to merit attention from a toxicological viewpoint. Experimentally, the radiation sensitivity of numerous constituents of the fruit has been compared with that of glucose and, apart from a few exceptions whose concentrations are minimal, results obtained agree well with predicted values [af

Generating Lie Point Symmetry Groups of (2+1)-Dimensional Broer-Kaup Equation via a Simple Direct Method

International Nuclear Information System (INIS)

Ma Hongcai

2005-01-01

Using the (2+1)-dimensional Broer-Kaup equation as an simple example, a new direct method is developed to find symmetry groups and symmetry algebras and then exact solutions of nonlinear mathematical physical equations.

Short Communication: A Simple Method for Performing Worm-Egg Counts on Sodium Acetate Formaldehyde-Preserved Samples

Directory of Open Access Journals (Sweden)

Wayne Melrose

2012-01-01

Full Text Available The Kato Katz method is the most common way of performing worm-egg counts on human faecal samples, but it must be done in the field using freshly collected samples. This makes it difficult to use in remote, poorly accessible situations. This paper describes a simple method for egg counts on preserved samples collected in the field and sent to a central location for further processing.

Field emission properties of nano-structured cobalt ferrite (CoFe2O4) synthesized by low-temperature chemical method

Science.gov (United States)

Ansari, S. M.; Suryawanshi, S. R.; More, M. A.; Sen, Debasis; Kolekar, Y. D.; Ramana, C. V.

2018-06-01

We report on the field-emission properties of structure-morphology controlled nano-CoFe2O4 (CFO) synthesized via a simple and low-temperature chemical method. Structural analyses indicate that the spongy-CFO (approximately, 2.96 nm) is nano-structured, spherical, uniformly-distributed, cubic-structured and porous. Field emission studies reveal that CFO exhibit low turn-on field (4.27 V/μm) and high emission current-density (775 μA/cm2) at a lower applied electric field of 6.80 V/μm. In addition, extremely good emission current stability is obtained at a pre-set value of 1 μA and high emission spot-density over large area (2 × 2 cm2) suggesting the applicability of these materials for practical applications in vacuum micro-/nano-electronics.

Morphological and chemical changes of dentin after applying different sterilization methods

Directory of Open Access Journals (Sweden)

Cláudio Antonio Talge Carvalho

Full Text Available Aim The present study evaluated the morphological and chemical changes of dentin produced by different sterilization methods, using scanning electron microscopy (SEM and energy-dispersive X-ray spectrometry (EDS analysis. Material and method Five human teeth were sectioned into 4 samples, each divided into 3 specimens. The specimens were separated into sterilization groups, as follows: wet heat under pressure; cobalt 60 gamma radiation; and control (without sterilization. After sterilization, the 60 specimens were analyzed by SEM under 3 magnifications: 1500X, 5000X, and 10000X. The images were analyzed by 3 calibrated examiners, who assigned scores according to the changes observed in the dentinal tubules: 0 = no morphological change; 1, 2 and 3 = slight, medium and complete obliteration of the dentinal tubules. The chemical composition of dentin was assessed by EDS, with 15 kV incidence and 1 μm penetration. Result The data obtained were submitted to the statistical tests of Kruskall-Wallis and ANOVA. It was observed that both sterilization methods – with autoclave and with cobalt 60 gamma radiation – produced no significant changes to the morphology of the dentinal tubules or to the chemical composition of dentin. Conclusion Both methods may thus be used to sterilize teeth for research conducted in vitro.

The concept and method of closed reduction and internal fixation: a new approach for the treatment of simple zygoma fractures.

Science.gov (United States)

Uda, Hirokazu; Kamochi, Hideaki; Sugawara, Yasushi; Sarukawa, Syunji; Sunaga, Ataru

2013-11-01

The authors have developed a new minimally invasive surgical procedure for simple zygoma fractures, a closed reduction and internal fixation method, that uses a cannulated cortical screw system. From 2007 to 2012, 42 selected patients with simple zygoma fractures without ocular problems or shear at the zygomatic frontal portion were treated with this method. The mean age of the patients was 33 years (range, 13 to 77 years). The authors achieved good repositioning, equivalent to results achieved with conventional procedures in all cases. No notable complication occurred except for minor infection in two cases. Mean operative time was 32 minutes (range, 19 to 58 minutes). Postoperative relapse was found only in the posterior direction (poperative time, less effect on soft tissue, maintenance of bone healing potential, and decreased postoperative pain and swelling. The authors concluded that this method has the potential to become a future surgical procedure for simple zygoma fractures. Therapeutic, IV.

APPLICATION OF CHEMICAL METHODS TO THE SOLID WASTE MANAGEMENT

Directory of Open Access Journals (Sweden)

C. P. Bulimaga

2008-12-01

Full Text Available The present article is a synthesis analysis of application of chemical methods for the development of technologies of hazardous waste management. Here are offered some technologies of neutralization of the waste containing hexacyanofferates, galvanic wastes and those with contain of vanadium, which are collected at Power Thermoelectric Plants.

An Energy Efficiency Evaluation Method Based on Energy Baseline for Chemical Industry

Directory of Open Access Journals (Sweden)

Dong-mei Yao

2016-01-01

Full Text Available According to the requirements and structure of ISO 50001 energy management system, this study proposes an energy efficiency evaluation method based on energy baseline for chemical industry. Using this method, the energy plan implementation effect in the processes of chemical production can be evaluated quantitatively, and evidences for system fault diagnosis can be provided. This method establishes the energy baseline models which can meet the demand of the different kinds of production processes and gives the general solving method of each kind of model according to the production data. Then the energy plan implementation effect can be evaluated and also whether the system is running normally can be determined through the baseline model. Finally, this method is used on cracked gas compressor unit of ethylene plant in some petrochemical enterprise; it can be proven that this method is correct and practical.

A simple and robust method for connecting small-molecule drugs using gene-expression signatures

Directory of Open Access Journals (Sweden)

Gant Timothy W

2008-06-01

Full Text Available Abstract Background Interaction of a drug or chemical with a biological system can result in a gene-expression profile or signature characteristic of the event. Using a suitably robust algorithm these signatures can potentially be used to connect molecules with similar pharmacological or toxicological properties by gene expression profile. Lamb et al first proposed the Connectivity Map [Lamb et al (2006, Science 313, 1929–1935] to make successful connections among small molecules, genes, and diseases using genomic signatures. Results Here we have built on the principles of the Connectivity Map to present a simpler and more robust method for the construction of reference gene-expression profiles and for the connection scoring scheme, which importantly allows the valuation of statistical significance of all the connections observed. We tested the new method with two randomly generated gene signatures and three experimentally derived gene signatures (for HDAC inhibitors, estrogens, and immunosuppressive drugs, respectively. Our testing with this method indicates that it achieves a higher level of specificity and sensitivity and so advances the original method. Conclusion The method presented here not only offers more principled statistical procedures for testing connections, but more importantly it provides effective safeguard against false connections at the same time achieving increased sensitivity. With its robust performance, the method has potential use in the drug development pipeline for the early recognition of pharmacological and toxicological properties in chemicals and new drug candidates, and also more broadly in other 'omics sciences.

A simple nodal force distribution method in refined finite element meshes

Energy Technology Data Exchange (ETDEWEB)

Park, Jai Hak [Chungbuk National University, Chungju (Korea, Republic of); Shin, Kyu In [Gentec Co., Daejeon (Korea, Republic of); Lee, Dong Won [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Cho, Seungyon [National Fusion Research Institute, Daejeon (Korea, Republic of)

2017-05-15

In finite element analyses, mesh refinement is frequently performed to obtain accurate stress or strain values or to accurately define the geometry. After mesh refinement, equivalent nodal forces should be calculated at the nodes in the refined mesh. If field variables and material properties are available at the integration points in each element, then the accurate equivalent nodal forces can be calculated using an adequate numerical integration. However, in certain circumstances, equivalent nodal forces cannot be calculated because field variable data are not available. In this study, a very simple nodal force distribution method was proposed. Nodal forces of the original finite element mesh are distributed to the nodes of refined meshes to satisfy the equilibrium conditions. The effect of element size should also be considered in determining the magnitude of the distributing nodal forces. A program was developed based on the proposed method, and several example problems were solved to verify the accuracy and effectiveness of the proposed method. From the results, accurate stress field can be recognized to be obtained from refined meshes using the proposed nodal force distribution method. In example problems, the difference between the obtained maximum stress and target stress value was less than 6 % in models with 8-node hexahedral elements and less than 1 % in models with 20-node hexahedral elements or 10-node tetrahedral elements.

Fast and simple method for semiquantitative determination of calcium propionate in bread samples.

Science.gov (United States)

Phechkrajang, Chutima Matayatsuk; Yooyong, Surin

2017-04-01

Calcium propionate has been widely used as a preservative in bakery and in bread. It is sometimes not carefully used, or a high concentration is added to preserve products. High consumption of calcium propionate can lead to several health problems. This study aims to develop a fast and simple semiquantitative method based on color complex formation for the determination of calcium propionate in a bread sample. A red-brown complex was obtained from the reaction of ferric ammonium sulfate and propionate anion. The product was rapidly formed and easily observed with the concentration of propionate anion >0.4 mg/mL. A high-performance liquid chromatography (HPLC) method was also developed and validated for comparison. Twenty-two bread samples from three markets near Bangkok were randomly selected and assayed for calcium propionate using the above two developed methods. The results showed that 19/22 samples contained calcium propionate >2000 mg/kg. The results of the complex formation method agreed with the HPLC method. Copyright © 2016. Published by Elsevier B.V.

Fast and simple method for semiquantitative determination of calcium propionate in bread samples

Directory of Open Access Journals (Sweden)

Chutima Matayatsuk Phechkrajang

2017-04-01

Full Text Available Calcium propionate has been widely used as a preservative in bakery and in bread. It is sometimes not carefully used, or a high concentration is added to preserve products. High consumption of calcium propionate can lead to several health problems. This study aims to develop a fast and simple semiquantitative method based on color complex formation for the determination of calcium propionate in a bread sample. A red–brown complex was obtained from the reaction of ferric ammonium sulfate and propionate anion. The product was rapidly formed and easily observed with the concentration of propionate anion >0.4 mg/mL. A high-performance liquid chromatography (HPLC method was also developed and validated for comparison. Twenty-two bread samples from three markets near Bangkok were randomly selected and assayed for calcium propionate using the above two developed methods. The results showed that 19/22 samples contained calcium propionate >2000 mg/kg. The results of the complex formation method agreed with the HPLC method.

A Rapid, Simple, and Validated RP-HPLC Method for Quantitative Analysis of Levofloxacin in Human Plasma

Directory of Open Access Journals (Sweden)

Dion Notario

2017-04-01

Full Text Available To conduct a bioequivalence study for a copy product of levofloxacin (LEV, a simple and validated analytical method was needed, but the previous developed methods were still too complicated. For this reason, a simple and rapid high performance liquid chromatography method was developed and validated for LEV quantification in human plasma. Chromatographic separation was performed under isocratic elution on a Luna Phenomenex® C18 (150 × 4.6 mm, 5 µm column. The mobile phase was comprised of acetonitrile, methanol, and phosphate buffer 25 mM that adjusted at pH 3.0 (13:7:80 v/v/v and pumped at a flow rate of 1.5 mL/min. Detection was performed under UV detector at wavelength of 280 nm. Samples were prepared by adding acetonitrile and followed by centrifugation to precipitate plasma protein. Then followed successively by evaporation and reconstitution step. The optimized method meets the requirements of validation parameters which included linearity (r = 0.995, sensitivity (LLOQ and LOD was 1.77 and 0.57 µg/mL respectively, accuracy (%error above LLOQ ≤ 12% and LLOQ ≤ 20%, precision (RSD ≤ 9%, and robustness in the ranges of 1.77-28.83 µg/mL. Therefore, the method can be used as a routine analysis of LEV in human plasma as well as in bioequivalence study of LEV.

A simple route to scalable fabrication of perfectly ordered ZnO nanorod arrays

International Nuclear Information System (INIS)

Liu, D F; Xiang, Y J; Liao, Q; Zhang, J P; Wu, X C; Zhang, Z X; Liu, L F; Ma, W J; Shen, J; Zhou, W Y; Xie, S S

2007-01-01

ZnO nanorod arrays with perfect order and uniformity were prepared using a simple, low-cost, commonly available and scalable nanosphere lithography for patterning gold catalyst particles and a successive bottom-up growth technique in a tube furnace chemical vapor deposition system. Each rod in the arrays had perfect surface facets, sharp edges and uniform size. For all of the rods, their sides were oriented the same. This bottom-up assembly method may accelerate the use of ZnO nanorods in real device applications

Investigation of chemical equilibrium kinetics by the electromigration method

International Nuclear Information System (INIS)

Bozhikov, G.A.; Ivanov, P.I.; Maslov, O.D.; Dmitriev, S.N.; Bontchev, G.D.; Milanov, M.V.

2003-01-01

The measurement of the chemical reaction rates for complex formation as well as hydrolysis type reactions by the method of horizontal zone electrophoresis is outlined. The correlation between chemical equilibrium kinetics and electrodiffusion processes in a constant d.c. electric field is described. In model electromigration experiments the reaction rate constant of the formation a complex by Hf(IV) and diethylenetriaminepentaacetic acid (DTPA) is determined. The electrophoretic mobility, diffusion coefficient and stability constant of the [HfDTPA] - complex are calculated, taking into account experimental electrophoretic data obtained at 298.15±0.05 K and constant ionic strength. No-carrier-added 175 Hf radionuclide was used in electromigration experiments at concentrations of 10 -10 -10 -11 M. (orig.)

A simple gamma spectrometry method for evaluating the burnup of MTR-type HEU fuel elements

Energy Technology Data Exchange (ETDEWEB)

Makmal, T. [The Unit of Nuclear Engineering, Ben-Gurion University of The Negev, Beer-Sheva 84105 (Israel); Nuclear Physics and Engineering Division, Soreq Nuclear Research Center, Yavne 81800 (Israel); Aviv, O. [Radiation Safety Division, Soreq Nuclear Research Center, Yavne 81800 (Israel); Gilad, E., E-mail: gilade@bgu.ac.il [The Unit of Nuclear Engineering, Ben-Gurion University of The Negev, Beer-Sheva 84105 (Israel)

2016-10-21

A simple method for the evaluation of the burnup of a materials testing reactor (MTR) fuel element by gamma spectrometry is presented. The method was applied to a highly enriched uranium MTR nuclear fuel element that was irradiated in a 5 MW pool-type research reactor for a total period of 34 years. The experimental approach is based on in-situ measurements of the MTR fuel element in the reactor pool by a portable high-purity germanium detector located in a gamma cell. To corroborate the method, analytical calculations (based on the irradiation history of the fuel element) and computer simulations using a dedicated fuel cycle burnup code ORIGEN2 were performed. The burnup of the MTR fuel element was found to be 52.4±8.8%, which is in good agreement with the analytical calculations and the computer simulations. The method presented here is suitable for research reactors with either a regular or an irregular irradiation regime and for reactors with limited infrastructure and/or resources. In addition, its simplicity and the enhanced safety it confers may render this method suitable for IAEA inspectors in fuel element burnup assessments during on-site inspections. - Highlights: • Simple, inexpensive, safe and flexible experimental setup that can be quickly deployed. • Experimental results are thoroughly corroborated against ORIGEN2 burnup code. • Experimental uncertainty of 9% and 5% deviation between measurements and simulations. • Very high burnup MTR fuel element is examined, with 60% depletion of {sup 235}U. • Impact of highly irregular irradiation regime on burnup evaluation is studied.

Study on magnetite nanoparticles synthesized by chemical method

International Nuclear Information System (INIS)

Pei Wenli; Kumada, H.; Natusme, T.; Saito, H.; Ishio, S.

2007-01-01

Magnetite nanoparticles with controlled size were synthesized by chemical method. Higher deposition temperature and a rapid-raising temperature procedure are favorable to particle size distribution and fabrication of monodisperse nanoparticles. The larger nanoparticles can be synthesized by the two-step method. The large nanoparticle (up to 25 nm) without agglomeration was successfully produced. The saturation magnetization of 11 nm magnetite particles was 45 emu/g at room temperature, which is smaller than that of bulk magnetite due to surface effect. Hysteresis of the magnetite nanoparticle was very small, indicating superparamagnetic behavior. The magnetic domains of the 11 nm magnetite nanoparticles were successfully observed by MFM

A simple method to fabricate an NIR detector by PbTe nanowires in a large scale

International Nuclear Information System (INIS)

Baghchesara, Mohammad Amin; Yousefi, Ramin; Cheraghizade, Mohsen; Jamali-Sheini, Farid; Saáedi, Abdolhossein; Mahmmoudian, M.R.

2016-01-01

Highlights: • PbTe nanowires were grown by tellurization of the Pb sheets for the first time. • It was observed a band gap value for the PbTe nanostructures in the NIR region. • NIR detector was fabricated in a large scale using a simple method. • Effect of Te concentration on morphology of PbTe nanostructures was investigated. - Abstract: A simple method was used to fabricate a near-infrared (NIR) detector using PbTe nanostructures. Samples were synthesized by tellurization of lead sheets in a tube furnace. PbTe nanostructures with wires and flakes shapes were grown on the lead sheets that were placed at 300 and 330 °C, respectively, while, PbTe nanoporous were grown at 360 and 390 °C. X-ray diffraction patterns and X-ray photoelectron spectra results indicated that, the PbTe phase was formed in all samples. UV–vis diffuse reflectance spectra measurements showed a band gap for the PbTe nanostructures in the near-infrared region of the electromagnetic spectrum. Actually, the results indicated that, the band gap values of the PbTe nanowires and nanoporous were 1.54 eV and 1.61 eV, respectively. Finally, the PbTe nanostructures were used as a simple photoresponse device under a red light source. The photoresponse results revealed, PbTe nanowires are promising for photoelectrical applications in the NIR region.

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-10-15

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

A simple method of digitizing analog scintigrams for quantification and digital archiving

International Nuclear Information System (INIS)

Schramm, M.; Kaempfer, B.; Wolf, H.; Clausen, M.; Wendhausen, H.; Henze, E.

1993-01-01

This study was undertaken to evaluate a quick, reliable and cheap method of digitizing analog scintigrams. 40 whole-body bone scintigrams were obtained simultaneously in analog and genuine digital format. The analog scans on X-ray film were then digitized seecondarily by three different methods: 300 dpi flatbed scanning, high-resolution camera scanning and camcorder recording. A simple exposure approach using a light box, a cheap camcorder, a PC and image grabber hard- and software proved to be optimal. Visual interpretation showed no differences in clinical findings when comparing the analog images with their secondarily digitized counterparts. To test the possibility of quantification, 126 equivalent ROIs were drawn both in the genuine digital and the secondarily digitized images. Comparing the ROI count to whole-body count percentage of the corresponding ROIs showed the correlation to be linear. The evaluation of phantom studies showed the linear correlation to be true within a wide activity range. Thus, secondary digitalization of analog scintigrams is an easy, cheap and reliable method of archiving images and allows secondary digital quantification. (orig.) [de

[A simple method of digitizing analog scintigrams for quantification and digital archiving].

Science.gov (United States)

Schramm, M; Kämpfer, B; Wolf, H; Clausen, M; Wendhausen, H; Henze, E

1993-02-01

This study was undertaken to evaluate a quick, reliable and cheap method of digitizing analog scintigrams. 40 whole-body bone scintigrams were obtained simultaneously in analog and genuine digital format. The analog scans on x-ray film were then digitized secondarily by three different methods: 300 dpi flat-bed scanning, high-resolution camera scanning and camcorder recording. A simple exposure approach using a light box, a cheap camcorder, a PC and image grabber hard- and software proved to be optimal. Visual interpretation showed no differences in clinical findings when comparing the analog images with their secondarily digitized counterparts. To test the possibility of quantification, 126 equivalent ROIs were drawn both in the genuine digital and the secondarily digitized images. Comparing the ROI count to whole-body count percentage of the corresponding ROIs showed the correlation to be linear. The evaluation of phantom studies showed the linear correlation to be true within a wide activity range. Thus, secondary digitalization of analog scintigrams is an easy, cheap and reliable method of archiving images and allows secondary digital quantification.

Development of a benchtop baking method for chemically leavened crackers. II. Validation of the method

Science.gov (United States)

A benchtop baking method has been developed to predict the contribution of gluten functionality to overall flour performance for chemically leavened crackers. Using a diagnostic formula and procedure, dough rheology was analyzed to evaluate the extent of gluten development during mixing and machinin...

Evaluation of the effect of salts on chemical, structural, textural, sensory and heating properties of cheese: Contribution of conventional methods and spectral ones.

Science.gov (United States)

Loudiyi, M; Aït-Kaddour, A

2018-03-21

Chemical composition, sensory characteristics, textural and functional properties are among the most important characteristics, which directly relates to the global quality of cheese and to consumer acceptability. A number of factors including milk composition, processing conditions and salt content, influences these properties. The past decades many investigations were performed on the possibilities to reduce salt content of cheese due to its adverse health effects, the current lifestyle and the awareness of the consumers for nutrition quality products. Due to the multiple potential effects of reducing NaCl (simple reduction or substitution) on cheese attributes, it is of utmost importance to identify and understand those effects in order to control the global quality and safety of the final product. In the present review a collection of the different results and conclusions drawn after studying the effect of salts by conventional (e.g. wet chemistry) and instrumental (e.g. spectral) methods on chemical, structural, textural, sensory and heating properties of cheese are presented.

Ammonia-free chemical bath method for deposition of microcrystalline cadmium selenide films

International Nuclear Information System (INIS)

Lokhande, C.D.; Lee, Eun-Ho; Jung, Kwang-Deog; Joo, Oh-Shim

2005-01-01

Chemical deposition of cadmium selenide (CdSe) films has been carried out from alkaline aqueous solution containing Cd 2+ and Se 2- ions. In general, the alkaline pH of the CdSe deposition bath has been adjusted by addition of liquid ammonia. However, the use of ammonia in large-scale chemical deposition method represents an environmental problem due to its volatility and toxicity. The volatility of ammonia changes the pH of deposition bath and results into irreproducible film properties. In the present paper, ammonia-free and weak alkaline (pH < 9.0) chemical method for cadmium selenide film has been developed. The cadmium selenide films are microcrystalline (grain size 0.5-0.7 μm) with hexagonal crystal structure. These films are photoactive and therefore, useful in photo conversion of light into electrical power

Deployment Analysis of a Simple Tape-Spring Hinge Using Probabilistic Methods

Science.gov (United States)

Lyle, Karen H.; Horta, Lucas G.

2012-01-01

Acceptance of new deployable structures architectures and concepts requires validated design methods to minimize the expense involved with technology validation flight testing. Deployable concepts for large lightweight spacecraft include booms, antennae, and masts. This paper explores the implementation of probabilistic methods in the design process for the deployment of a strain-energy mechanism, specifically a simple tape-spring hinge. Strain-energy mechanisms are attractive for deployment in very lightweight systems because they do not require the added mass and complexity associated with motors and controllers. However, designers are hesitant to include free deployment, strain-energy mechanisms because of the potential for uncontrolled behavior. In the example presented here, the tapespring cross-sectional dimensions have been varied and a target displacement during deployment has been selected as the design metric. Specifically, the tape-spring should reach the final position in the shortest time with the minimal amount of overshoot and oscillations. Surrogate models have been used to reduce computational expense. Parameter values to achieve the target response have been computed and used to demonstrate the approach. Based on these results, the application of probabilistic methods for design of a tape-spring hinge has shown promise as a means of designing strain-energy components for more complex space concepts.

A Simple PCR Method for Rapid Genotype Analysis of Mycobacterium ulcerans

Science.gov (United States)

Stinear, Timothy; Davies, John K.; Jenkin, Grant A.; Portaels, Françoise; Ross, Bruce C.; OppEdIsano, Frances; Purcell, Maria; Hayman, John A.; Johnson, Paul D. R.

2000-01-01

Two high-copy-number insertion sequences, IS2404 and IS2606, were recently identified in Mycobacterium ulcerans and were shown by Southern hybridization to possess restriction fragment length polymorphism between strains from different geographic origins. We have designed a simple genotyping method that captures these differences by PCR amplification of the region between adjacent copies of IS2404 and IS2606. We have called this system 2426 PCR. The method is rapid, reproducible, sensitive, and specific for M. ulcerans, and it has confirmed previous studies suggesting a clonal population structure of M. ulcerans within a geographic region. M. ulcerans isolates from Australia, Papua New Guinea, Malaysia, Surinam, Mexico, Japan, China, and several countries in Africa were easily differentiated based on an array of 4 to 14 PCR products ranging in size from 200 to 900 bp. Numerical analysis of the banding patterns suggested a close evolutionary link between M. ulcerans isolates from Africa and southeast Asia. The application of 2426 PCR to total DNA, extracted directly from M. ulcerans-infected tissue specimens without culture, demonstrated the sensitivity and specificity of this method and confirmed for the first time that both animal and human isolates from areas of endemicity in southeast Australia have the same genotype. PMID:10747130

A simple linear regression method for quantitative trait loci linkage analysis with censored observations.

Science.gov (United States)

Anderson, Carl A; McRae, Allan F; Visscher, Peter M

2006-07-01

Standard quantitative trait loci (QTL) mapping techniques commonly assume that the trait is both fully observed and normally distributed. When considering survival or age-at-onset traits these assumptions are often incorrect. Methods have been developed to map QTL for survival traits; however, they are both computationally intensive and not available in standard genome analysis software packages. We propose a grouped linear regression method for the analysis of continuous survival data. Using simulation we compare this method to both the Cox and Weibull proportional hazards models and a standard linear regression method that ignores censoring. The grouped linear regression method is of equivalent power to both the Cox and Weibull proportional hazards methods and is significantly better than the standard linear regression method when censored observations are present. The method is also robust to the proportion of censored individuals and the underlying distribution of the trait. On the basis of linear regression methodology, the grouped linear regression model is computationally simple and fast and can be implemented readily in freely available statistical software.

A fast and simple GC MS method for lignan profiling in Anthriscus sylvestris and biosynthetically related plant species

NARCIS (Netherlands)

Koulman, A; Bos, R; Medarde, M; Pras, N; Quax, WJ

2001-01-01

A new GC-MS method for monitoring lignans was developed to study the variation in plants and elucidate the biosynthetic steps. A simple and fast extraction procedure for lyophilised plant material was developed, giving a lignan-rich extract. A GC-MS method was set up using an apolar WCOT fused

Alternative Chemical Amplification Methods for Peroxy Radical Detection

Science.gov (United States)

Wood, E. C. D.

2014-12-01

Peroxy radicals (HO2, CH3O2, etc.) are commonly detected by the chemical amplification technique, in which ambient air is mixed with high concentrations of CO and NO, initiating a chain reaction that produces 30 - 200 NO2 molecules per sampled peroxy radical. The NO2 is then measured by one of several techniques. With the exception of CIMS-based techniques, the chemical amplification method has undergone only incremental improvements since it was first introduced in 1982. The disadvantages of the technique include the need to use high concentrations of CO and the greatly reduced sensitivity of the amplification chain length in the presence of water vapor. We present a new chemical amplification scheme in which either ethane or acetaldehyde is used in place of CO, with the NO2 product detected using Cavity Attenuated Phase Shift spectroscopy (CAPS). Under dry conditions, the amplification factor of the alternative amplifiers are approximately six times lower than the CO-based amplifier. The relative humidity "penalty" is not as severe, however, such that at typical ambient relative humidity (RH) values the amplification factor is within a factor of three of the CO-based amplifier. Combined with the NO2 sensitivity of CAPS and a dual-channel design, the detection limit of the ethane amplifier is less than 2 ppt (1 minute average, signal-to-noise ratio 2). The advantages of these alternative chemical amplification schemes are improved safety, a reduced RH correction, and increased sensitivity to organic peroxy radicals relative to HO2.

Simple method based on intensity measurements for characterization of aberrations from micro-optical components.

Science.gov (United States)

Perrin, Stephane; Baranski, Maciej; Froehly, Luc; Albero, Jorge; Passilly, Nicolas; Gorecki, Christophe

2015-11-01

We report a simple method, based on intensity measurements, for the characterization of the wavefront and aberrations produced by micro-optical focusing elements. This method employs the setup presented earlier in [Opt. Express 22, 13202 (2014)] for measurements of the 3D point spread function, on which a basic phase-retrieval algorithm is applied. This combination allows for retrieval of the wavefront generated by the micro-optical element and, in addition, quantification of the optical aberrations through the wavefront decomposition with Zernike polynomials. The optical setup requires only an in-motion imaging system. The technique, adapted for the optimization of micro-optical component fabrication, is demonstrated by characterizing a planoconvex microlens.

A vector/parallel method for a three-dimensional transport model coupled with bio-chemical terms

NARCIS (Netherlands)

B.P. Sommeijer (Ben); J. Kok (Jan)

1995-01-01

textabstractA so-called fractional step method is considered for the time integration of a three-dimensional transport-chemical model in shallow seas. In this method, the transport part and the chemical part are treated separately by appropriate integration techniques. This separation is motivated

Stochastic Order Redshift Technique (SORT): a simple, efficient and robust method to improve cosmological redshift measurements

Science.gov (United States)

Tejos, Nicolas; Rodríguez-Puebla, Aldo; Primack, Joel R.

2018-01-01

We present a simple, efficient and robust approach to improve cosmological redshift measurements. The method is based on the presence of a reference sample for which a precise redshift number distribution (dN/dz) can be obtained for different pencil-beam-like sub-volumes within the original survey. For each sub-volume we then impose that: (i) the redshift number distribution of the uncertain redshift measurements matches the reference dN/dz corrected by their selection functions and (ii) the rank order in redshift of the original ensemble of uncertain measurements is preserved. The latter step is motivated by the fact that random variables drawn from Gaussian probability density functions (PDFs) of different means and arbitrarily large standard deviations satisfy stochastic ordering. We then repeat this simple algorithm for multiple arbitrary pencil-beam-like overlapping sub-volumes; in this manner, each uncertain measurement has multiple (non-independent) 'recovered' redshifts which can be used to estimate a new redshift PDF. We refer to this method as the Stochastic Order Redshift Technique (SORT). We have used a state-of-the-art N-body simulation to test the performance of SORT under simple assumptions and found that it can improve the quality of cosmological redshifts in a robust and efficient manner. Particularly, SORT redshifts (zsort) are able to recover the distinctive features of the so-called 'cosmic web' and can provide unbiased measurement of the two-point correlation function on scales ≳4 h-1Mpc. Given its simplicity, we envision that a method like SORT can be incorporated into more sophisticated algorithms aimed to exploit the full potential of large extragalactic photometric surveys.

A comparison of the microstructures and electrochemical capacitive properties of 2 graphenes prepared by arc discharge method and chemical method

Energy Technology Data Exchange (ETDEWEB)

Zhang, H.; Yang, Y. [Research Inst. of Chemical Defense, Beijing (China); Univ. of Science and Technology, Beijing (China); Cao, G.; Xu, B. [Research Inst. of Chemical Defense, Beijing (China)

2010-07-01

In this study, 2 kinds of graphene materials were prepared using both arc discharge and chemical methods. The pore structures and electrochemical capacitive properties of the materials were investigated. A mesopore structure was obtained for the graphene prepared using the arc discharge method, with a capacitance of 12.9 F/g and a high rate capability when used in electrochemical applications. The graphene prepared with the chemical method demonstrated a more highly developed micropore structure and capacitances greater than 70 F/g. However, rate performance for the graphene was normal. 2 figs.

CADDIS Volume 2. Sources, Stressors and Responses: Unspecified Toxic Chemicals

Science.gov (United States)

Intro to the unspecified toxic chemicals module, when to list toxic chemicals as a candidate cause, ways to measure toxic chemicals, simple and detailed conceptual diagrams for toxic chemicals, toxic chemicals module references and literature reviews.

A simple and sensitive method for the determination of fibric acids in the liver by liquid chromatography.

Science.gov (United States)

Karahashi, Minako; Fukuhara, Hiroto; Hoshina, Miki; Sakamoto, Takeshi; Yamazaki, Tohru; Mitsumoto, Atsushi; Kawashima, Yoichi; Kudo, Naomi

2014-01-01

Fibrates are used in biochemical and pharmacological studies as bioactive tools. Nevertheless, most studies have lacked information concerning the concentrations of fibric acids working inside tissues because a simple and sensitive method is not available for their quantitation. This study aimed to develop a simple and sensitive bioanalytical method for the quantitation of clofibric, bezafibric and fenofibric acids in samples of very small portions of tissues. Fibric acids were extracted into n-hexane-ethyl acetate from tissue homogenates (10 mg of liver, kidney or muscle) or serum (100 µL) and were derivatized with 4-bromomethyl-6,7-dimethoxycoumarin, followed by HPLC with fluorescence detection. These compounds were separated isocratically on a reversed phase with acetonitrile-water. Standard analytical curves were linear over the concentration range of 0.2-20 nmol/10 mg of liver. Precision and accuracy were within acceptable limits. Recovery from liver homogenates ranged from 93.03 to 112.29%. This method enabled the quantitation of fibric acids in 10 mg of liver from rats treated with clofibric acid, bezafibric acid or fenofibrate. From these analytical data, it became clear that there was no large difference in ratio of acyl-CoA oxidase 1 (Acox1) mRNA level to fibric acid content in the liver among the three fibric acids, suggesting that these three fibric acids have similar potency to increase expression of the Acox1 gene, which is a target of peroxisome proliferator-activated receptor α. Thus, the proposed method is a simple, sensitive and reliable tool for the quantitation of fibric acids working in vivo inside livers.

General survey of detection methods for irradiation foods

International Nuclear Information System (INIS)

Yang, J. S.

1997-01-01

The development of detection techniques is needed, in order for regulating authorities to determine whether or not a particular food sample has been irradiated, and label it accordingly so that a consumer's free choice can be exercised. The chemical and physical changes brought about in foods by practical doses of irradiation are very small, and therefore very sensitive methods are required. A number of promising approaches have been developed and evaluated. These include chemical, physical and biological methods ranging from the very simple to highly sophisticated techniques. (author)

Simple and efficient method for isolation and cultivation of endoscopically obtained human colonocytes

DEFF Research Database (Denmark)

Seidelin, Jakob B; Horn, Thomas; Nielsen, Ole H

2003-01-01

and where the diagnosis of irritable bowel syndrome was later reached, were included. Seven colon biopsies were taken and incubated at varying time periods of 10-120 min and temperatures of 4-37 degrees C in a chelating buffer. The epithelium was then harvested and cultivated under three different......Few comparative and validated reports exist on the isolation and growth of colonoscopically obtained colonic epithelium. The aim of this study was to develop and validate a simple method for the cultivation of colonoscopically obtained colonocytes. Forty patients, who underwent routine colonoscopy...

A Simple and Effective Isocratic HPLC Method for Fast Identification and Quantification of Surfactin

International Nuclear Information System (INIS)

Muhammad Qadri Effendy Mubarak; Abdul Rahman Hassan; Aidil Abdul Hamid; Sahaid Khalil; Mohd Hafez Mohd Isa

2015-01-01

The aim of this study was to establish a simple, accurate and reproducible method for the identification and quantification of surfactin using high-performance liquid chromatography (HPLC). Previously reported method of identification and quantification of surfactin were time consuming and requires a large quantity of mobile phase. The new method was achieved by application of Chromolith® high performance RP-18 (100 x 4.6 mm, 5 μm) as the stationary phase and optimization of mobile phase ratio and flow rate. Mobile phase consisted of acetonitrile (ACN) and 3.8 mM trifluroacetic acid (TFA) solution of 80:20 ratio at flow rate of 2.2 mL/ min was obtained as the optimal conditions. Total elution time of the obtained surfactin peaks was four times quicker than various methods previously reported in the literature. The method described here allowed for fine separation of surfactin in standard sample (98 % purity) and surfactin in fermentation broth. (author)