Academic literature on the topic 'Solvent chloroform'

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Journal articles on the topic "Solvent chloroform"

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Saraswati, Sagung Ayu Bulan Julia, Luh Putu Wrasiati, and Ni Made Wartini. "KARAKTERISTIK PEWARNA ALAMI DARI EKSTRAK KULIT BUAH JERUK MANDARIN (Citrus reticulata) PADA PERBANDINGAN PELARUT ETANOL DAN KLOROFORM." JURNAL REKAYASA DAN MANAJEMEN AGROINDUSTRI 6, no. 4 (2018): 278. http://dx.doi.org/10.24843/jrma.2018.v06.i04.p02.

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Orange fruit who be the superior commodity is known as a fruit who rich of its vitamin C. One kind of orange who really liked by the society is Mandarin Orange (Citrus reticulata) that comes from China. The aims of this research were to know the effect of ethanol and chloroform solvent ratio to the characteristic of the natural colorant from Mandarin orange peel extract and determine the best ethanol and chloroform solvent ratio which produced Mandarin orange peel extract as natural colorant. Experimental design in this research used Randomized Block Design by using the comparison of ethanol and chloroform solvents that consist of 6 levels, there are: ethanol : chloroform (0:10); ethanol : chloroform (2:8); ethanol : chloroform (4:6); ethanol : chloroform (6:4); ethanol : chloroform (8:2); ethanol : chloroform (10:0). The treatment was repeated as many as 3 repetitions then obtained 18 units of the experiment. The data were analyzed by variance and if the treatment had a effect on the variable then continued with Duncan test. The result showed that ethanol and chloroform solvent ratio had significant effect on the yield, the total carotenoids content, the level of brightness (L*), the level of redness (a*), the level of yellowness (b*) of Mandarin orange peel extract. Based on the results of index effectiveness test used five expert, the ethanol and chloroform solvent ratio of 0 :10 produced the best characteristic of Mandarin orange peel extract with the yield 4.83 ± 0.22f (%), the total carotenoids content 3.56 ± 0.20a (%), the level of brightness (L*) 31.34 ± 0.63d, the level of redness (a*) 28.39 ± 0.69a, and the level of yellowness (b*) 34.52 ± 0.18a.
 Keywords : Citrus reticulata, extraction, ethanol, chloroform, natural colorant
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Shephard, J. J., A. K. Soper, S. K. Callear, S. Imberti, J. S. O. Evans, and C. G. Salzmann. "Polar stacking of molecules in liquid chloroform." Chemical Communications 51, no. 23 (2015): 4770–73. http://dx.doi.org/10.1039/c4cc09235j.

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Smith, John F., and Loren G. Hepler. "Examination of the inert solvent assumption in the ideal associated solution model. Enthalpy of chloroform–triethylamine complex dissociation." Canadian Journal of Chemistry 67, no. 7 (1989): 1153–57. http://dx.doi.org/10.1139/v89-174.

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We have made new measurements of the enthalpies of adding cyclohexane to mixtures of chloroform + triethylamine + cyclohexane at 25 °C. The results of these measurements have been analysed in terms of the ideal associated solution model to obtain ΔHθ for the dissociation of the chloroform-triethylamine complex. Our value of ΔHθ is in excellent agreement with a published value that was obtained from results of measurements on binary mixtures of chloroform + triethylamine. This agreement indicates that it is usefully accurate to treat mixtures of chloroform + triethylamine + cyclohexane as ideal mixtures of chloroform, triethylamine, cyclohexane, and chloroform-triethylamine complex. This result has important implications for studies of associated systems dissolved in "inert" solvents and helps to provide a connection between complex formation in dilute solutions and in binary systems (A + B, no solvent). Keywords: ideal associated solution model, chloroform, triethylamine, inert solvent, hydrogen bonded complex.
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Bayram, Emre, Dilek Dalat, and Melike Bayram. "Solubility Evaluation of Different Root Canal Sealing Materials." Journal of Contemporary Dental Practice 16, no. 2 (2015): 96–100. http://dx.doi.org/10.5005/jp-journals-10024-1643.

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ABSTRACT Aim To evaluate the solubility of five different root canal sealers (AH Plus Jet, RealSeal SE, MTA Fillapex, Tubli-Seal, and Acroseal) in chloroform, eucalyptol and Endosolv-E solvents. Materials and methods Ninety root canal sealer samples were prepared and then divided into three groups for immersion in a solvent for 2, 5 or 10 minutes. The mean values of the root canal sealers’ dissolution in the solvents were obtained by the difference between the preimmersion original weight and the post-immersion weight on a digital analytical scale. Data were statistically analyzed by a Kruskal-Wallis test with a Bonferroni correction. Results Chloroform was a more effective solvent than eucalyptol or Endosolv E for all root canal sealers, except for RealSeal SE, at all time points (p < 0.003). RealSeal SE was the least soluble sealer in all solvents at all time points. Conclusion Chloroform demonstrated a superior ability over other solvents in dissolving canal sealing materials, and eucalyptol was found to be the least effective solvent in this study. Clinical significance This study can help to the clinicians about which solvent should be preferred for solving the filling materials in retreatment cases. How to cite this article Bayram E, Dalat D, Bayram M. Solubility Evaluation of Different Root Canal Sealing Materials. J Contemp Dent Pract 2015;16(2):96-100.
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Bosits, Miklós Hunor, Emese Pálovics, János Madarász, and Elemér Fogassy. "New Discoveries in Enantiomeric Separation of Racemic Tofisopam." Journal of Chemistry 2019 (April 7, 2019): 1–10. http://dx.doi.org/10.1155/2019/4980792.

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Resolution process of tofisopam has been re-evaluated now based on our new investigations. Originally, it was carried out in the water-chloroform system, where the intermediate salt of high diastereomeric excess was described as (R)-TOF·(R,R)-DBTA·(H2O)3. Opposed to previous assumptions, we have actually found that a different solvate composition, (R)-TOF‐(R,R)-DBTA-CHCl3, forms with chloroform, in which molecules of CHCl3 are captured and held with different strengths. Moreover, resolution of TOF with (R,R)-DBTA is possible (and favourable) in water-free solvent and solvent mixture. However, presence of chloroform is essential, and thus, chloroform is also a suitable solvent alone. Among the tested solvents, toluene-chloroform mixture results in the highest resolution efficiency, while the highest enantiomeric purity was achieved when acetonitrile was in the system too. Resolution efficiency can be also increased by using the quasi-racemic resolving agent and thermodynamic control. Purification of enantiomeric mixtures was examined, and recrystallization of the diastereomeric salt was found to be the most efficient solution. Instructive behaviour of the complex enantiomer-conformer system of tofisopam is emphasized.
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Jednačak, Tomislav, Maja Majerić Elenkov, Tomica Hrenar, Karlo Sović, Jelena Parlov Vuković, and Predrag Novak. "Solution and solid state studies of hydrogen bonding in substituted oxazolidinones by spectroscopic and quantum chemical methods." New Journal of Chemistry 44, no. 16 (2020): 6456–63. http://dx.doi.org/10.1039/c9nj06349h.

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Udaya Prakash N K, Sriraman V, Devika V, et al. "Comparative studies on phytochemistry, antioxidant and antibacterial activity of direct and sequential extracts of chromolaena odorata leaves." International Journal of Research in Pharmaceutical Sciences 10, no. 2 (2019): 914–21. http://dx.doi.org/10.26452/ijrps.v10i2.275.

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Phytochemistry, antioxidant and antibacterial activities of different solvent extracts of Chromolaena odorata leaves obtained by direct and sequential extraction were compared in this study. Antibacterial evaluation of the extracts was performed through a disc diffusion method. The results revealed that the solvents, Petroleum ether and Ethyl acetate showed the presence of a majority of the phytochemicals, Chloroform extract yielded maximum TPC and TAA and ethyl acetate yielded higher TFC when compared to other solvents. Ethanol and chloroform extracts showed lower concentrations of IC50 against DPPH and NO radicals respectively. Acetone recorded the maximum zone of inhibition against Staphylococcus aureus and Pseudomonas aeruginosa; ethyl acetate against Bacillus subtilis and Chloroform against Streptococcus mutans. Among the solvents studied for phytochemical content and bioactivities, ethanol showed a higher level of phytochemical extraction and better bioactivities. As a direct solvent extraction of C. odorata showed better efficiency when compared with sequential extraction, the study strongly recommends the use of a direct extraction method.
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Dewi, Kurnia Harlina, Markom Masturah, and Wan Ramli Wan Daud. "Parameter Optimization in the Extraction of Sea Cucumber (Holothuria scabra j) as a Source of Testosterone." Advanced Materials Research 233-235 (May 2011): 1358–65. http://dx.doi.org/10.4028/www.scientific.net/amr.233-235.1358.

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Testosterone, the steroid hormone used in sex reversal and as an aphrodisiac, is produced not only by sea cucumber, but many other organisms too. This research was aimed at optimizing conventional extraction of testosterone from sea cucumber, looking at method, type of solvent, solvent ratio, and temperature for isolation. The results showed that extraction by reflux produced the highest testosterone content, followed by soxhlet extraction. The lowest yield was produced by maceration extraction. The solvents selected were acetone, methanol, methanol/chloroform mixture (1:2) and chloroform. The highest result was obtained by methanol/chloroform (0.2728 mg /100g dry weight (dw)), followed by acetone (0.2623 mg), chloroform (0.1606 mg) and methanol (0.0920 mg). Ratios of material:solvent used were 1:1, 1:2 and 1:3 respectively. Results improved as the amount of solvent was increased, so a ratio of 1:3 was most successful and 1:1 least successful. The effects of temperature and time on scale-up reflux extraction were also studied. Scale-up reflux extraction of 3000 ml showed that raising the temperature increases the percentage of sea cucumber extract.
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Satheesh, Arjun, A. A. Alagiriswamy, S. Devanand, and S. Nithiyanantham. "Solvent Assisted Coaxial-Electrospun Poly Methyl Methacrylate Polymer and Study of Resultant Fibers." Sensor Letters 18, no. 12 (2020): 905–9. http://dx.doi.org/10.1166/sl.2020.4296.

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Electrospinning of dispersions with higher viscosity and limited flow may be carried out, based on the solvent assisted coaxial technique, where the flow of the core dispersion is supported by a free flowing sheath solvent. In the present work, the sheath solvents used are chloroform, toluene and dimethyl formamide and we discuss the fiber formation of Poly Methyl Methacrylate (PMMA) (dispersion-25 wt%). PMMA dispersed in chloroform is taken as the core solution and the sheath is pure solvent. The In-Situ effect of different sheath solvents in fiber formation at two different tip to collector distances are studied. The fibers formed are subjected to SEM analysis and the characteristics are analysed. The fiber formation of high viscos polymer dispersions makes the same materials subjectable to electrospinning and further applications.
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Lee, Chong M., Belzahet Trevino, and Mayuree Chaiyawat. "A Simple and Rapid Solvent ExtractionMethod for Determining Total Lipids in Fish Tissue." Journal of AOAC INTERNATIONAL 79, no. 2 (1996): 487–92. http://dx.doi.org/10.1093/jaoac/79.2.487.

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Abstract Solvent systems that have been developed for lipid extraction include chloroform–methanol, n-hexane– isopropyl alcohol, and methylene chloride–metha nol. The extraction methods are labor intensive, lack precision, or require a large volume of solvent. Correct computation of lipid content calls for full recovery of solvent after extraction, but recovery always is incomplete because of unaccounted solvent residue that remains in jar, filter paper, and homogenized tissue. A rapid and simple extraction method coupled with correct computation was developed for determining total lipids in fish tissue. The method uses chloroform–methanol and an Eberbach blending jar. Variables examined were chloroform–methanol ratio, solvent-to-sample ratio, and phase separation time. Precision was within 0.5%. Conventional computation of lipid content depends on the volume of chloroform measured after filtration. This volume does not include unaccounted solvent residue. Thus, a time-consuming second extraction is required for complete recovery. The mass balance of each extraction and filtration step confirmed that the correct volume of chloroform (measured plus unaccounted) was close to the theoretical volume. The procedure eliminates problems associated with laborious filtration and variation in chloroform volume readings and does not require an exact reading of chloroform volume. Instead it allows use of a theoretical volume, which depends on solvent volume and ratio used.
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Dissertations / Theses on the topic "Solvent chloroform"

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Boman, Andreas, and Jakob Selvin. "Softening Efficacy of Various Solvents on Gutta-percha and Root Canal Sealer." Thesis, Umeå universitet, Institutionen för odontologi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-129389.

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Solvents have been used in endodontic retreatment for a long time and the dissolving effect is well proven. Latterly chloroform has come in a bad light due to its possible carcinogenicity. Despite the negative health effect it is still used in dental environment. Other more biocompatible solvents have now reached the market and tests should be performed to evaluate the softening efficacy. The purpose of this in-vitro study was to evaluate the softening efficacy of four different solvents used in endodontics; chloroform, eucalyptol, tetrachloroethylene, orange-oil and a control group. 100 simulated canals filled with gutta-percha, epoxy amine resin based sealer, zinc oxide eugenol based sealer and non eugenolcalcium hydroxide based sealer were tested with hardness measurement before and after two minutes exposure time of medicament. Non-eugenol calcium hydroxide failed to set and was excluded from the test. A Shore A durometer was used to evaluate the hardness of the materials and all data was first analyzed with Kruskal-Wallis test and then Mann-Whitney test to compare with control group. With a digital camera connected to a microscope we also took pictures to compare the impressions with the different medicaments. The result showed that chloroform and tetrachloroethylene is significant better to soften gutta-percha than control group (p < 0.05) but only chloroform significant better than control group to soften epoxy amine resin based sealer and zinc oxide eugenol based sealer (p < 0.05). Even if the result was significant, we cannot draw any conclusions due to small sample size.
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Liu, Feng, Lei Zhang, Yue Zhang, Stefan C. B. Mannsfeld, Thomas P. Russell, and Alejandro L. Briseno. "Interpenetrating morphology based on highly crystalline small molecule and PCBM blends." Royal Society of Chemistry, 2014. https://tud.qucosa.de/id/qucosa%3A36260.

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We report the morphological characterization of triisopropylsilylethynyl-dibenzochrysene (TIPS-DBC:PCBM) blends, a bulk heterojunction (BHJ) solar cell system based on a highly crystalline small molecule donor. We found that processing the blends from a volatile solvent such as chloroform is beneficial in controlling the crystal size and phase separation of the donor–acceptor phases. When a less-volatile solvent such as chlorobenzene is used, large crystalline domains formed, exceeding the length scale suitable for BHJ solar cells. When the BHJ films are thermally annealed, enhanced domain purity is observed for the chloroform processed thin films, which led to an increased short circuit current in the devices.
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Tse, Mara. "Biocatalysis of tyrosinase in chloroform medium using selected phenolic substrates." Thesis, McGill University, 1996. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=27427.

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The biocatalytic activity of mushroom tyrosinase was optimized in chloroform medium, using five selected phenolic substrates, including catechin (CT), vanillin (VA), chlorogenic acid (CA), p-aminophenol (pAP) and hydroquinone (HQ). The specific activity (SA) of tyrosinase determined as the change in absorbance at the selected wavelength per $ mu$g protein per sec ($ delta$A/$ mu$g protein/sec) in chloroform was much higher than that obtained in aqueous media. The optimal amount of enzymatic protein for tyrosinase biocatalysis in chloroform was found to be 44.0 mg protein/L for CT and VA, 31.6, 180.5 and 90.3 mg protein/L, respectively, for CA, pAP and HQ. The optimal pH for the oxidative activity of tyrosinase in chloroform was 6.0 for all the substrates; however, the optimal temperature for enzymatic activity was 30$ sp circ$C for CT and 25$ sp circ$C for the other four substrates. The use of 1.25 and 6.65 mM catechol in chloroform medium activated the tyrosinase activity maximally by 56.2% and 267.2%, respectively for CT and CA as substrates; however, no effect from catechol (0 to 7 mM) was found with VA, pAP or HQ. In addition, the use of 4.25, 2.25 and 5.39 mM ethylenediamine tetraacetic acid (EDTA) in chloroform, with CT, VA and pAP as substrates, inhibited the tyrosinase activity maximally by 44.3, 84.7 and 67.0%, respectively; however, the use of 4.75 and 1.60 mM EDTA activated the enzyme by 101.9% and 115.9%, respectively, for CA and HQ. The use of high-performance liquid chromatography (HPLC) and capillary electrophoresis (CE) demonstrated the phenolic substrate bioconversion, whereas the spectrophotometric scanning showed the product formation during the enzymatic reaction. (Abstract shortened by UMI.)
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Nordborg, Daniel. "Provtagning av trädkärnor för att bedöma föroreningsgraden av klorerade lösningsmedel i grundvatten." Thesis, Uppsala University, Department of Earth Sciences, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-88820.

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<p>Chlorinated aliphatic hydrocarbons (CAH´s) were used widely within dry cleaning facilities and for metal degreasing until their toxicity was discovered. PCE is still used as dry cleaning liquid. Today CAH´s are found in soil environment at places where they have been used in the past. The CAH-concentration in trees growing on contaminated land has quite recently received attention as a cheap and effective way of assessing the extent of a CAH-contamination. The method has however, not been put into use in Sweden.</p><p>The aim of the study has been to investigate whether the CAH-concentration in tree cores could be used to delineate the spread of CAH in a soil environment under Swedish conditions in different seasons. The aim has also been to gain an understanding of the uptake process, as well as to identify the limitations of the method and important issues to consider when sampling.</p><p>Trees were sampled in March and June on Helgö 1:25, 1:26 in Växjö, Småland. Metal degreasing earlier conducted at this site has lead to the CAH contamination of soil and groundwater (PCE, TEC c-DACE). Mostly PCE, TCE, and chloroform were detected in tree cores. The CAH concentration was higher in June. Using the sum of PCE+TCE+c-DCE in trees to delineate the spread gave a result that was quite consistent with a delination done based on groundwater sampling.</p><p>The uptake of CAH by trees is governed by the uptake of water at the root. The water usage, together with the origin of the water used is important for the ability of the tree to take up CAH. The CAH concentration within trees is also dependent on the chemical properties of the compound (Log kow, solubility etc), the concentration of the compound in the soil as well as degradation processeses. The position and height of sampling in the trees, tree species as well as tree size are important factors to consider when sampling. Sampling during summer is preferred when the concentration of CAH in trees is likely to be higher.</p><p>The analysis of CAH in tree cores has potential to be used as a screening tool in soil investigations under Swedish conditions. It is a cheap and easy to use method, which would be a good complement to other investigative measures. However, an increased understanding of the processes involved, together with more analysis are needed., as this is a new method.</p><br><p>Klorerade lösningsmedel (CAH) användes i stor omfattning som bl a kemtvättmedel och avfettningsmedel tills dess att deras toxiska egenskaper blev kända. Perkloretylen (PCE) används än idag som kemtvättmedel. CAH återfinns ofta i markmiljö på de platser där de tidigare använts. Analys av CAH-koncentration i trädkärnor har uppmärksammats som en billig och effektiv metod för att översiktligt bedöma utbredningen av dessa föroreningar. Metoden har inte tidigare använts i Sverige.</p><p>Syftet med detta examensarbete är att undersöka om trädprovtagning kan användas för att bedöma utbredningen av föroreningar i markmiljö under svenska förhållanden vid olika årstider.</p><p>Analyserade CAH-halter i träd har jämförts med tidigare registrerade halter av CAH i grundvatten. Syftet har också varit att beskriva CAH-upptaget i träd, undersöka metodens begränsningar samt att sammanfatta viktiga aspekter vid provtagning.</p><p>Provtagningar av träd har genomförts under mars och juni på fastigheterna Helgö 1:25 och 1:26 i Växjö, där tidigare metallavfettning har medfört att mark och grundvattnet förorenats av CAH; perkloretylen (PCE), trikloretylen (TCE) och nedbrytningsprodukten dikloretylen (c1,2-DCE). Vid analys av trädkärnor detekterades främst PCE, TCE samt TCM (kloroform). Koncentrationen av CAH var högre i juni. Halten PCE+TCE+c-DCE i trädproverna gav en översiktlig bild av föroreningssituationen som överensstämde väl med de grundvattenprover som tidigare tagits på fastigheten.</p><p>CAH tas upp i vattenlöst fas vid trädens rötter. Trädets vattenbehov och vilket vatten det utnyttjar är därför viktigt för dess möjlighet att ta upp CAH. Ämnets kemiska egenskaper (log kow, flyktighet, mm.), samt förekomst och nedbrytning påverkar den halt som registreras i trädet. Vid provtagning bör provtagningspunkternas höjd över marken och position, trädart samt trädstorlek beaktas. Provtagning under sommaren är att föredra eftersom halterna då är högre.</p><p>Jämförelsen med grundvattenprovtagning visar att metoden har potential att användas i Sverige för att bedöma utbredningen av en CAH-förorening i markmiljö. Den är enkel att använda och kan vara ett alternativ på platser där konventionella metoder är svåra att genomföra. En ökad förståelse för involverade processer, samt utökade undersökningar av metoden är nödvändiga då metoden är ny.</p>
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Ganne, Nadine. "Contribution à l'étude de l'élimination par stripping à l'air de solvants chlores contenus dans l'eau." Toulouse, INSA, 1988. http://www.theses.fr/1988ISAT0002.

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Les 3 solvants consideres sont: le chloroforme et tri- et tetrachloroethylene. Deux types d'installations sont utilises: un reacteur triphasique a lit fixe, rempli de pouzzolane ou les phases circules a co-courant vers le haut et une colonne a garnissage a contre courant. Determination des parametres hydrodynamiques (retention, perte de charge, modele d'ecoulement et aire interfaciale) et de transfert de matiere. On etudie aussi l'influence du debit d'eau et d'air, de la temperature et de la nature du solvant. Une derniere partie est consacree au dimensionnement optimal des colonnes a garnissage a contre-courant
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Karolina, Vukoje. "Endodontski retretman-analiza skening elektronskom mikroskopijom." Phd thesis, Univerzitet u Novom Sadu, Medicinski fakultet u Novom Sadu, 2015. http://www.cris.uns.ac.rs/record.jsf?recordId=95491&source=NDLTD&language=en.

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U slučajevima neuspe&scaron;ne endodontske terapije, neophodno je ponovno lečenje kanala korena. Ortogradni endodontski retretman podrazumeva uklanjanje postojećeg materijala za punjenje iz kanala uz dodatno či&scaron;ćenje, dezinfekciju i ponovnu finalnu opturaciju kanala. Važan korak u toku retretmana je &scaron;to potpunije uklanjanje postojećeg kanalnog punjenja kako bi se pristupilo svim delovima kanalnog sistema. Cilj doktorske teze bio je da se ispita kvalitet čis&scaron;ćenja zidova kanala korena nakon endodontskog retretmana pomoću skening elektronske mikroskopije (SEM). Posmatran je uticaj vrste materijala za opturaciju, uticaj upotrebe rastvarača i uticaj ručnih i ma&scaron;inskih instrumenata na količinu zaostalog materijala na zidovima kanala. Takođe, ispitan je uticaj ovih faktora na apikalnu transportaciju materijala i na vreme potrebno za retretman, a utvrđena je i učestalost o&scaron;tećenja kori&scaron;ćenih instrumenata. Materijal i metode: Ukupan uzorak činilo je 125 ekstrahovanih, humanih jednokorenih zuba. Nakon preparacije kanala korena, 120 zuba je podeljeno u dve grupe i napunjeno pomoću dva različita materijala za opturaciju (gutaperkom i resilonom). U zavisnosti od tehnike uklanjanja ovih materijala, grupe su dalje podeljene u odnosu na kori&scaron;ćene instrumente (Hedstrom, ProTaper i Twisted File) i u odnosu na upotrebu rastvarača (sa i bez hloroforma). Preostalih 5 zuba, bez kanalnog punjenja, kori&scaron;ćeni su kao kontrolna grupa. Nakon zavr&scaron;enog retretmana, korenovi su uzdužnim cepanjem razdvojeni, a odabrane polovine posmatrane na SEM-u. Mikrofotografije svake trećine kanala načinjene su pri uveličanju od 500x. Količina preostalog materijala za punjenje ocenjivana je pomoću skale. Otvoreni dentinski kanalići prebrojavani su na mikrofotografijama načinjenim pri uveličanju od 1000x, u odnosu na uvek konstantnu povr&scaron;inu. Rezultati: Analiza rezultata ukazala je na postojanje statistički značajne razlike u kvalitetu či&scaron;ćenja zidova kanala u zavisnosti od uklanjanog materijala za opturaciju. Kvalitet či&scaron;ćenja zidova kanala bio je veći nakon uklanjanja gutaperke nego nakon uklanjanja resilona. Rotirajućim, ma&scaron;inskim instrumentima je efikasnije uklanjana gutaperka, a ručnim Hedstrom turpijama je bolje uklanjan resilon. Posmatrajući ceo uzorak, ProTaper instrumenti ostavljali su velike količine materijala na zidovima kanala nakon endodontskog retretmana. Međutim, uklanjanje materijala pomoću ovih instrumenata bilo je najbrže. Primena rastvarača značajno je doprinela bržem uklanjanju materijala, dok uticaj na kvalitet či&scaron;ćenja zidova kanala nije bio značajan. Posmatrajući kanal korena po trećinama, najveća količina materijala nalazila se u apikalnoj trećini, bez obzira na vrstu uklanjanog materijala i kori&scaron;ćenih instrumenata, i bez obzira na upotrebu rastvarača tokom retretmana. Učestalost o&scaron;tećenja instrumenata bila je značajno veća prilikom upotrebe Twisted File instrumenata. Apikalna transportacija materijala je bila veća tokom uklanjanja resilon materijala i kada su kori&scaron;ćene ručne Hedstrom turpije. Zaključak: Kvalitet či&scaron;ćenja zidova kanala nakon uklanjanja gutaperke je veći nego nakon uklanjanja resilona. Dizajn i vrsta instrumenata utiče na kvalitet či&scaron;ćenja zidova kanala korena. Upotreba rastvarača tokom retretmana ne utiče značajno na smanjenje količine materijala zaostalog na zidovima kanala. Ma&scaron;inski pokretani instrumenti i upotreba rastvarača značajno skraćuju vreme potrebno za endodontski retretman.<br>In cases when endodontic treatment fails, it is necessary to retreat the root canal. Orthograde endodontic retreatment requires the removal of the existing root filling material with additional cleaning, disinfection and refilling of the canal. An important step during retreatment is complete removal of existing filling materials, to regain access to all parts of the canal system. The aim of the doctoral thesis was to investigate the cleanliness of root canal walls after removal of two different obturation material. The retreatment efficacy was observed depending on the usage of solvent and different hand or rotary instruments. The amount of residual material on the canal walls was assessed using scanning electron microscopy (SEM). Also, apical transportation of the obturation material, working time and frequency of instrument damage during retreatment was recorded. Materials and Methods: The total sample consisted of 125 extracted, single-rooted human teeth. After root canal preparation, 120 teeth were divided in two groups and filled using two different obturation materials (gutta-percha and resilon). Depending on the technique of removing these materials, the groups were further divided, in relation to the used instruments (Hedstrom, ProTaper and Twisted File), as well as in relation to the use of solvent (with or without chloroform). The remaining 5 tooth without canal filling were used as a control group. After root canal desopturation, the longitudinaly splitted root halves were observed on SEM. Microphotography of each third were made at magnification of 500x. The amount of remaining filling material was evaluated by using a scale. Open dentinal tubules were counted on microphotographies made at a magnificiation of 1000x, on a surface that was always constant. Results: Analysis of the results indicated a significant difference in the cleanliness of the canal walls depending on the used obturation material. Cleanliness of the canal walls was higher after gutta-percha removal than after the removal of resilon.&nbsp; Rotary instruments were more effective in removing gutta-percha and Hedstrom hand files better removed resilon. ProTaper instruments left more residual material on canal walls, however endodontic retreatment with these instruments was the fastest. The application of solvent significantly contributed to faster material removal, while the impact on the increase of canal cleanliness was not significant. The largest amount of material remained in the apical third, regardless of the type of material removed and instruments used, and also regardless whether solvent was used for retreatment. The frequency of instrument deformation and fracture was significantly higher when Twisted File instruments were used. Apical transportation of material had a significantly higher occurrence during resilon removal and when manual Hedstrom files were used. Conclusion: Cleanliness of the canal walls was higher after the removal of gutta-percha than after the removal of resilon. The use of solvent is not significant on the increase of canal wall cleanliness, but significantly shortens the time needed for retreatment. There is a difference in the cleanliness of root canal walls depending on the used instruments. Engine-driven rotary instruments and the use of a solvent significantly shortens the time needed for endodontic retreatment.
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Books on the topic "Solvent chloroform"

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O'Brien, James. The Scientific Sherlock Holmes. Oxford University Press, 2013. http://dx.doi.org/10.1093/oso/9780199794966.001.0001.

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One of the most popular and widely known characters in all of fiction, Sherlock Holmes has an enduring appeal based largely on his uncanny ability to make the most remarkable deductions from the most mundane facts. The very first words that Sherlock Holmes ever says to Dr. Watson are, "How are you? You have been in Afghanistan, I perceive." Watson responds, "How on earth did you know that?" And so a crime-solving legend is born. In The Scientific Sherlock Holmes, James O'Brien provides an in-depth look at Holmes's use of science in his investigations. Indeed, one reason for Holmes's appeal is his frequent use of the scientific method and the vast scientific knowledge which he drew upon to solve mysteries. For instance, in heart of the book, the author reveals that Holmes was a pioneer of forensic science, making use of fingerprinting well before Scotland Yard itself had adopted the method. One of the more appealing aspects of the book is how the author includes real-world background on topics such as handwriting analysis, describing how it was used to capture the New York Zodiac killer and to clinch the case against the Lindbergh baby kidnapper. Sherlock Holmes was knowledgeable about several sciences, most notably chemistry. Therefore the book takes a close look at Holmes the chemist and discusses, for example, chemical poisons such as carbon monoxide, chloroform, and Prussic acid (the historical name for hydrogen cyanide). The author also debunks Isaac Asimov's famous assertion that Holmes was a blundering chemist. In addition, the book discusses mathematics, physics, biology, astronomy, meteorology, and geology, always in the context of Holmes's exploits. Sherlock Holmes continues to fascinate millions of readers and movie goers alike. The Scientific Sherlock Holmes is a must-read for the legion of fans of this most beloved of all fictional detectives.
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Book chapters on the topic "Solvent chloroform"

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Lauterbach, M., and G. Wipff. "Liquid-Liquid Extraction of Alkali Cations by Calix[4]Crown Ionophores: Conformation and Solvent Dependent Na+/Cs+ Binding Selectivity. A MD FEP Study in Pure Chloroform and MD Simulations at the Water/Chloroform Interface." In Physical Supramolecular Chemistry. Springer Netherlands, 1996. http://dx.doi.org/10.1007/978-94-009-0317-3_6.

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Tlili, Anis, and Johannes Schranck. "The Application of Dichloromethane and Chloroform as Reagents in Organic Synthesis." In Solvents as Reagents in Organic Synthesis. Wiley-VCH Verlag GmbH & Co. KGaA, 2017. http://dx.doi.org/10.1002/9783527805624.ch4.

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Smallwood, Ian M. "Chloroform." In Handbook of Organic Solvent Properties. Elsevier, 1996. http://dx.doi.org/10.1016/b978-0-08-052378-1.50038-4.

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Seco, Josi M., Emilio Quiqoa, and Ricardo Riguera. "Practical Aspects of the Preparation of the Derivatives." In The Assignment of the Absolute Configuration by NMR using Chiral Derivatizing Agents. Oxford University Press, 2015. http://dx.doi.org/10.1093/oso/9780199996803.003.0005.

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Most of the NMR spectra shown in this book and in the literature have been recorded at 250 or 300 MHz, with a few being obtained at 500 MHz for 1H NMR (the equivalent for 13C NMR). No special pulse sequences are necessary, just standard one-dimensional (1D) spectra although two-dimensional (2D) experiments (e.g., correlation spectroscopy; COSY) may be necessary in some cases in order to get an unambiguous identification of the signals relevant for the assignment. In general, 5–10 mg or less of CDA derivative dissolved in 0.5 mL of deuterated solvent are sufficient to obtain a good NMR spectrum. Temperature, solvent, and concentration used in the NMR experiments should be adequate for each CDA-substrate pair and methodology, because the method is based on the conformational composition of the AMAA derivatives in precise conditions. With the exception of the low-temperature procedure (single derivatization), a NMR probe temperature around 300 K has always been used. In general, the spectra for double-derivatization assignments should be taken in deuterated chloroform. Different NMR solvents are required only in two of the single-derivatization methods. In the assignment by low-temperature NMR, the most convenient solvent is a CS2/CD2Cl2 (4:1) mixture, which allows the use of temperatures low enough (i.e., 213 K) to obtain relevant shifts. In the procedure based on the complexation with Ba2+, the NMR solvent should be deuterated acetonitrile. The barium salt is anhydrous Ba(ClO4)2, which can be added directly to the tube by using a spatula. No weighing is necessary after shaking, as the excess salt will remain at the bottom of the NMR tube and will not disturb the experiment. (R)- and (S)-MPA, MTPA, and Boc-phenylglycine (BPG) are commercially available and can be used without further purification. The first two (MPA and MTPA) can also be purchased as acid chlorides. When using MTPA or the corresponding acid chloride [85] for the derivatization of an alcohol or amine, it should be noted that the Cahn-Ingold-Prelog priority rules assign different R/S descriptors to the acid and to the corresponding chloride; this is due to the different priority order generated by the substituents [i.e., (R)-MTPA generates the (S)-acid chloride and vice versa].
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Domingo, M. Aviado, Samir Zakhari, and Tetsuya Watanabe. "Methyl Chloroform." In Non-fluorinated Propellants and Solvents for Aerosols, edited by Leon Golberg. CRC Press, 2018. http://dx.doi.org/10.1201/9781351075015-1.

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"are purified lipid contents and others are not, and the puri-(Paspalum scrobiculatum), and barnyard (Echinocloa fied lipid content depends on the purification method. colona). Sridhar and Lakshminarayana [32] also reported Starch lipids (SL) are those bound to starch, and they FL contents of 5.0, 5.6, and 2.2% for Proso, Foxtail, and are the most difficult to extract. Since true SL are present Finger millet, respectively. Taira [45] found slightly high-inside the starch granules, even a very polar solvent such er average FL (ether extraction) contents for glutinous as WSB cannot extract them at ambient temperature. Effi-foxtail millet (4.2-5.1%, average 4.7% of 21 samples) cient extraction of SL requires mixtures of hot aqueous al-than for nonglutinous foxtail millet (4.0-4.7%, average cohol in proportions optimized for controlled swelling of 4.4% of 31 samples). Among millet, pearl millet contains the starch granules and solubilization of the lipids [25]. the most FL. The best solvents are n-propanol or isopropanol with water Lipid contents of rice in Table 2 were cited by Morrison (3:1, by volume) used under nitrogen at 100°C. However, [3] using the data of Nechaev and Sandler [2]. Taira and some n-butanol—water and methanol-water mixtures also Chang [46] reported that the average nonglutinous brown are reasonably efficient extraction solvents at 100°C [25]. rice FL (ether extraction) contents of 20 varieties each of Recently, a third lipid category was introduced. Starch sur-Indica and Japonica types were 2.7% (2.38-2.91%) and face lipids (SSL) are portions of the nonstarch lipids 2.9% (2.54-3.58%), respectively. More recently, Taira et (NSL), which become firmly absorbed onto or into starch al. [47] reported the average FL contents of 15 nongluti-granules during the separation of pure starch [24]. nous varieties as 2.5% (2.24-2.97%) for Indica, 2.5% Lipids are minor components of the cereal grains shown (2.12-2.94%) for Japonica, 2.7% (2.35-3.03%) for Sinica, in Table 2. Data in this table, expressed on a dry basis, and 2.6% (2.11-2.99%) for Japonica types. were calculated from reported values [3,16,26-41]. Also, some BL or TL contents were calculated by subtracting FL from TL or by adding FL to BL, depending on the avail-B. Nonstarch Lipid Classes of Grains ability of data. The FL contents range from 1.5 to 2% of Lipids can be separated into three broad classes by open-the kernel weights of barley, rice, rye, triticale, and wheat column silicic acid chromatography. Nonpolar lipids (NL) grains. They range from 3 to 7% of the kernel weights of are first eluted by chloroform, glycolipids (GL) are eluted oats, millet, corn, and sorghum. However, BL contents in next by acetone, and phospholipids (PL) are eluted last grains are more uniform than FL contents. Therefore, the with methanol. Mixtures of GL and PL are polar lipids FL:BL ratio is substantially higher for corn, millet, oats, (PoL). After NL elution from a silicic acid column, PoL and sorghum than for rye, triticale, and wheat grains. The can be eluted with methanol without the GL elution step. FL:BL ratios for barley and rice are intermediate. Lipids can also be separated into various classes by thin-High oil-containing grains such as corn are continuous-layer chromatography (TLC) using different development ly bred for higher oil content with improved production solvent systems. Each individual lipid class migrates dif-yield. Application of wide-line NMR spectroscopy for ferently on the thin-layer plate, and the difference in mi-nondestructive analysis of the oil content in single corn gration rates makes it possible to separate complex lipids kernels made selection for higher oil content more efficient into classes. The NL consists of SE, TG, DG, MG, and [42]. Corn hybrids with 6-8.5% oil content and grain FFA (see Table 1). The total NL content is obtained by yields equal to those of good commercial hybrids were adding these NL class contents as measured by densitome-produced [43]. try. Thus, the NL content of samples may differ, to some Several kinds of millet exist, and the lipid data in the extent, depending on methodology used (column separa-literature are confusing. Rooney compared the FL (ether tion or TLC separation). extraction) contents of several types of millet in a review The data [1,13,27,29,32,36-38,40,48-58] shown in paper [16]. The average FL contents of pearl millet (Pen-Table 3 may be used for only approximate comparison of nisetum typhoids) were 5.1% (4.1-5.6%, 14 samples), the NL content from different grains because some were 5.4% (2.8-8.0%, 167 samples, [44]), 5.6% (4.3-7.1%, 40 obtained by column chromatography and some by TLC. samples), and 6.2% (4.2-7.4%, 35 samples) [16]. Other All cereal grain lipids are richer in NL than in other class-reported average FL contents were 4.8% (4.6-5.0%, 6 es: 60-70% of the TL are NL in wheat (hexaploid), triti-samples) for foxtail millet (Setaria Italica), 5.8% cale, and rye; 65-80% for barley and oat groats; 77-87% (5.5-6.3%, 6 samples) for Japanese millet (Echinochloa for sorghum and rice; and 75-96% for corn and millet crusgalli), and 4.2% (3.8-4.9%, 20 samples) for proso (Pennisetum americanum). Sridhar and Lakshminarayana millet (Panicum miliaceum) [16]. Sridhar and Lakshmi-[32] reported 82, 80, and 79% of NL for Foxtail, Proso, narayana [30] reported a FL content range of 3.4-5.7% for and Finger millet, respectively. There are significant vari-small millet, including little (Panicum sumatrense), kodo etal effects on the NL/PoL ratio for corn and millet (P." In Handbook of Cereal Science and Technology, Revised and Expanded. CRC Press, 2000. http://dx.doi.org/10.1201/9781420027228-43.

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Conference papers on the topic "Solvent chloroform"

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Rizvi, Reza R., Jae K. Kim, and Hani E. Naguib. "Processing and MWNT Composition Effects on the Thermal, Electrical and Mechanical Properties of PLA-MWNT Composites." In ASME 2009 International Mechanical Engineering Congress and Exposition. ASMEDC, 2009. http://dx.doi.org/10.1115/imece2009-11314.

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This paper investigates the processing and its effects and the effect of multiwall carbon nanotube (MWNT) composition on the thermal, electrical and mechanical properties of polylactide (PLA)-MWNT composites. The composite films were prepared by a solvent casting process using two solvents, chloroform and 1,4-dioxane. The dispersion of the MWNTs in PLA was examined using a scanning electron microscope and was found to be more improved when 1,4-dioxane was used as the solvent as compared to chloroform. The thermal characteristics of the composites were examined on Differential Scanning Calorimetry and Thermo-gravimetric Analysis. Composites prepared using 1,4-dioxane had greater improvements in composite decomposition temperature, glass transition temperature and displayed faster crystallization kinetics. The mechanical properties of the composites were tested in uniaxial tension. Composites prepared using chloroform had a lower modulus than composites prepared using 1,4-dioxane. The electrical AC conductivity of the composites was measured over a broad frequency spectrum. Composites prepared using 1,4-dioxane displayed electrical percolation at 0.5 wt.% MWNT in PLA while percolation was absent in 0.5 wt.% MWNT composites prepared using chloroform.
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Barbosa, Ana Carolina Moralles, and Nelson H. Morgon. "Effect of solvent molecules on the UV-Vis electronic spectra." In VIII Simpósio de Estrutura Eletrônica e Dinâmica Molecular. Universidade de Brasília, 2020. http://dx.doi.org/10.21826/viiiseedmol202082.

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The effect of explicit molecules of solvent in the electronic spectrum of anhydride maleic groups was studied by quantum-chemical methods in ethanol and chloroform. An implicit method of solvation was also applied and showed no distinction between the two solvents. The addition of eight explicit molecules of the solvent resulted in an improvement of the calculated UV-Vis spectra. It was also possible to analyze the influence of different solvents in the molecular orbital associated with electronic transitions.
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Rizvi, Reza R., Jae K. Kim, and Hani E. Naguib. "Thermal, Electrical and Mechanical Properties of Blended and Solvent Cast PLA-MWNT Composites." In ASME 2009 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. ASMEDC, 2009. http://dx.doi.org/10.1115/smasis2009-1314.

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This paper compares melt blending and solvent casting as processing routes for fabricating Polylactide (PLA)-Multiwall carbon nanotube (MWNT) composites. Composites with an MWNT content of 0, 0.5, 2 and 5 wt.% MWNT were fabricated using both processing techniques and their thermal, electrical and mechanical properties were evaluated. Two types of solvents, chloroform and 1,4-dioxane, were used to disperse MWNTs in PLA when preparing the solvent cast composites. Melt blended PLA-MWNT composites were prepared in a mini twin-screw compounder at a temperature of 165 °C. Samples from both processing techniques were characterized for thermal, electrical and mechanical attributes. Scanning electron microscope (SEM) results indicated that composites prepared using solvent casting had a better MWNT dispersion in PLA. In particular, 1,4-dioxane was considerably more effective in dispersing MWNT than chloroform. Composites prepared using melt blending contained large sized MWNT aggregates suggesting that greater shear mixing or more suitable MWNT surface functionalization is required.
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Liu, Chun-Yuan, Wei-Ren Chang, Wei-Bor Tsai, and Pen-Hsiu Grace Chao. "Effect of Solvent on Electrospun PLLA Fiber Mechanical Characteristics and Ligament Fibroblast Responses." In ASME 2010 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2010. http://dx.doi.org/10.1115/sbc2010-19339.

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Due to the poor healing ability of anterior cruciate ligaments (ACL), surgical interventions with graft materials are often needed to reconstruct the knee joint. Electrospinning is widely utilized to manufacture highly aligned fibrous materials. When cultured on such substrates, ligament fibroblasts are known to exhibit elongation and enhanced collagen production [1, 2]. Poly-L-lactic-acid (PLLA) is a popular biocompatible material with high mechanical strength, and is most often used in electrospinning with chloroform as solvent. Hexafluoropropanol (HFP), another solvent, generates more uniform and consistent electrospun PLLA fibers. In this study, we investigated the effects of electrospun PLLA fiber scaffolds using different solvent on ligament tissue engineering. PLLA fibers electrospun with chloroform or HFP were compared for their structure and mechanical characteristics. We also investigated their effects on ligament cell morphology and proliferation. Further analysis of composite fiber bilayers were also performed [3].
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Burge, Scott R. "Automated Analysis of Trichloroethene and Chloroform." In ASME 2003 9th International Conference on Radioactive Waste Management and Environmental Remediation. ASMEDC, 2003. http://dx.doi.org/10.1115/icem2003-4648.

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Chloroform and trichloroethene (TCE) are two organic contaminants commonly encountered in ground water. TCE, formerly a common cleaning solvent, is usually associated with contaminated aquifers. Chloroform is usually associated with the chlorination of municipal water. The remediation level for TCE in aquifers is typically 5 ppb, therefore, the analytical method employed for monitoring these analytes must be capable of detecting and quantifying the analytes in the low ppb concentration range. The most common analytical methodology for the determination of TCE or chloroform in water is a purge and trap technique for sample introduction into a gas chromatographic system equipped with electroconductivity or mass spectroscopy detector. The instrumentation has a method limit of detection (LOD) of less than 0.5 ppb for TCE and chloroform, however, the expense, size and complexity of the gas chromatographic techniques limit its use outside the laboratory environment. An alternative to the gas chromatographic method for the analysis of select volatile chlorinated compounds in the low concentration range is an analytical instrument based on a halocarbon-specific optrode. The principle of detection is a quantitative, irreversible chemical reaction (modified Fujiwara reaction) that forms visible light-absorbing products. The operational basis of the optrode is the measure of the time history of the development of the colored (red) product formed by the reaction of the target analytes. The optrode has the selectivity and sensitivity for monitoring TCE and chloroform at the low ppb concentration range in the presence of other volatile chlorinated contaminants. The low-power requirements and simplicity of design make it a good choice for remote operations. This paper presents the analytical results (January 2002, to December 2002) of a panel-mounted instrument used to monitor the influent and effluent water of a TCE treatment facility located in Scottsdale, Arizona, and the analytical results of a well-mounted instrument used to monitor ground water (May 2002, to August 2002) at Edwards Air Force Base, California.
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Deneanu, Nicoleta, Magdalena Dianu, and Ion Teoreanu. "Packaging and Conditioning of Solvent Wastes From Decontamination Operation Cernavoda NPP." In ASME 2003 9th International Conference on Radioactive Waste Management and Environmental Remediation. ASMEDC, 2003. http://dx.doi.org/10.1115/icem2003-4759.

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Solvent wastes produced at Cernavoda NPP consist of miscellaneous acetone, toluene, methanol, chloroform, triclorethan, white spirit and ethylene glycol. These are normally LLW containing only relatively small quantities of beta/gamma emitting radionuclides and varying amounts of tritium with activity below E08Bq/l. This paper is a review of some current innovative work of Waste Management Facility from Institute for Nuclear Research Pitesti in the development of a viable solidification technology to convert solvent wastes into a stable monolithic form, which minimises the probability to release tritium in the environment during interim storage, transportation and final disposal. The paper presents the author’s research on immobilisation of solvent wastes by cementation using aluminium stearate additive. A quality assurance program should accompany the production of waste forms. The goal of all tests should be to obtain a license for a certain process from a competent authority. The process will be clean, which means there will be no secondary waste and low doses to the personnel will be achieved; the product quality will meet any National requirement and the reproducibility of the process meets any QA requirement.
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Yin, Sudong, Ryan Dolan, and Zhongchao Tan. "Hydrothermal Conversion of Cattle Manure to Biooil: Biooil Definitions." In ASME 2009 International Mechanical Engineering Congress and Exposition. ASMEDC, 2009. http://dx.doi.org/10.1115/imece2009-10286.

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A number of researchers have reported that biooil was produced through hydrothermal conversion of different types of biomass. However, it is difficult to evaluate and compare these biooils in terms of yields and chemical properties. They applied different organic solvents to extract biooil from products after hydrothermal conversion of biomass. The purpose of this study is to assess the impact of extraction solvents on the quantity and chemical structure of biooil. Cattle manure was used as one type of biomass feedstock for biooil production. And dichloromethane (CH2Cl2), chloroform (CHCl3) and diethyl ether (C4H10O) were used for biooil extraction. Results showed that extraction solvents influenced biooil yields. The highest biooil yield of 48.78 wt% of volatile content of cattle manure was obtained when using CH2Cl2 solvent. The main components of biooil extracted by CH2Cl2 and CHCl3 were ketones and carboxylic acids, while those extracted by C4H10O were aromatic chemicals. In terms of elemental compositions and high heating values of biooil, no statistically apparent differences were caused by different solvents. The mean elemental compositions (by weight) of biooils were carbon of 73.79%, hydrogen of 8.18%, nitrogen of 4.38% and oxygen of 13.65%. And the mean high heating value of biooil was 36.74 MJ/kg.
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Altomare, L., S. Fare`, L. Draghi, and M. C. Tanzi. "Effect of Microgrooved Surfaces on Fibroblast Cells Orientation." In ASME 8th Biennial Conference on Engineering Systems Design and Analysis. ASMEDC, 2006. http://dx.doi.org/10.1115/esda2006-95487.

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It is well known that cells can interact with patterned surfaces; although the mechanisms are still not clear, substrata containing periodic patterns of parallel grooves can impose directional constraints on cells and affect the rate and direction of cell migration. The aim of our work is to evaluate the possibility of replicating microgrooved surfaces by soft lithography and to assess, in vitro, the influence of three different microgrooved surfaces on fibroblasts alignment. Microgrooved substrata were obtained by Replica Molding out of two different polymers: PLLATMC and ChronoFlex AL from three different masters. From each master, a silicon mold was prepared and the polymers were casted in the mold using chloroform as solvent. By SEM and laser profilometry analysis we observed a good reproducibility of the different surfaces. The obtained results indicate that Replica Molding technique is an accurate method to reproduce a wide number of micropatterned surfaces with different polymers. In vitro tests with L929 murine fibroblasts showed different degrees of cellular alignment and elongation depending on grooves width.
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Shim, Jin-Hyung, Jong Young Kim, Kyung Shin Kang, Jung Kyu Park, Sei Kwang Hahn, and Dong-Woo Cho. "Development of HA-PLGA Scaffold Encapsulating Intact BMP-2 Using Solid Freeform Fabrication Technology." In ASME 2011 International Manufacturing Science and Engineering Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/msec2011-50259.

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Tissue engineering is an interdisciplinary field that focuses on restoring and repairing tissues or organs. Cells, scaffolds, and biomolecules are recognized as three main components of tissue engineering. Solid freeform fabrication (SFF) technology is required to fabricate three-dimensional (3D) porous scaffolds to provide a 3D environment for cellular activity. SFF technology is especially advantageous for achieving a fully interconnected, porous scaffold. Bone morphogenic protein-2 (BMP-2), an important biomolecule, is widely used in bone tissue engineering to enhance bone regeneration activity. However, methods for the direct incorporation of intact BMP-2 within 3D scaffolds are rare. In this work, 3D porous scaffolds with poly(lactic-co-glycolic acid) chemically grafted hyaluronic acid (HA-PLGA), in which intact BMP-2 was directly encapsulated, were successfully fabricated using SFF technology. BMP-2 was previously protected by poly(ethylene glycol) (PEG), and the BMP-2/PEG complex was incorporated in HA-PLGA using an organic solvent. The HAPLGA/PEG/BMP-2 mixture was dissolved in chloroform and deposited via a multi-head deposition system (MHDS), one type of SFF technology, to fabricate a scaffold for tissue engineering. An additional air blower system and suction were installed in the MHDS for the solvent-based fabrication method. An in vitro evaluation of BMP-2 release was conducted, and prolonged release of intact BMP-2, for up to 28 days, was confirmed. After confirmation of advanced proliferation of pre osteoblasts, a superior differentiation effect of the HA-PLGA/PEG/BMP-2 scaffold was validated by measuring high expression levels of bone-specific markers, such as alkaline phosphatase (ALP) and osteocalcin (OC). We show that our solvent-based fabrication is a non-toxic method for restoring cellular activity. Moreover, the HAPLGA/PEG/BMP-2 scaffold was effective for bone regeneration.
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Jayasuriya, A. Champa, Chiragkumar Shah, Vijay Goel, and Nabil A. Ebraheim. "Characterization of Biomimetic Mineral Coated 3D PLGA Scaffolds." In ASME 2006 International Mechanical Engineering Congress and Exposition. ASMEDC, 2006. http://dx.doi.org/10.1115/imece2006-14877.

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Abstract:
The bone-like carbonate apatite (BLCA) coatings can be coated biomimetically in the polymer surfaces by soaking in the simulated body fluid (SBF). This SBF contains similar ionic constituents to human blood plasma. Micro-porous 3D poly(lactic-co-glycolic acid) PLGA scaffolds were fabricated by the solvent casting/salt leaching technique using chloroform to dissolve the polymer. We accelerated the deposition of mineral on scaffolds for 1-2 days, modifying the mineralization process using surface treatments and 5x SBF. These scaffolds were analyzed by Scanning Electron Microscopy (SEM), Fourier Transform Infra-Red (FTIR) and X-ray Diffraction (XRD). The scaffolds coated with BLCA layer were placed in the 24 well plates containing 2 ml of media, such as Tris Buffered Saline-pH 7.4, cell culture media containing αMEM supplemented with 10% FBS, and 1% penicillin-streptomycin and incubated at 37°C for 21 days. The BLCA layer on surfaces of scaffold was stable even after 21 days immersed in Tris Buffered Saline and cell culture media. This study suggests that BLCA were stable for at least 3 weeks in the both media, and therefore, mineral has a potential to use as a carrier for biological molecules for localized release applications as well as bone tissue engineering applications.
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