White Precipitate Research Articles

Solubility of Trehalose in Water + Ethanol Solvent System from (288.15 to 318.15) K

The solubility of trehalose in a water + ethanol solvent system was measured with the mole fraction of water ranging from 0.000 to 1.000 at temperatures from (288.15 to 318.15) K using the gravimetric method. There was a minimum point on each solubility curve at the mole fraction of water ranging from 0.040 to 0.050. The differential scanning calorimetry measurement results show that anhydrous trehalose (a white flocculent precipitate) appeared in the suspension at water content lower than the critical point. While higher than that point, the crystals in the slurry were still hydrous polymorph which is apparently different from the anhydrous one. The solubility data at water content lower and higher than the critical points were nonlinear surface fitted separately using the combination version of the Jouyban-Acree and van’t Hoff models which is a three-dimensional (3D) model. The average relative deviation (ARD) values for trehalose solubility at water content lower and higher than the critical point were...

Development of biomimetic gelatin–chitosan/hydroxyapatite nanocomposite via double diffusion method for biomedical applications

Abstract In this research, nanocomposite scaffolds were prepared from gelatin/chitosan and hydroxyapatite via a biomimetic method. The prepared scaffolds were then evaluated by means of commonly used bulk techniques: X-ray diffraction, scanning electron microscopy and Fourier transform infra-red spectroscopy. In this study, the gelatin–chitosan/apatite nanocomposite scaffolds were fabricated using the applied biomimetic method accompanied by freeze drying. The apatite was formed using double diffusion within the gelatin/chitosan hydrogel at similar pH and temperature to the human body. The obtained nanocomposites were soaked in glutaraldehyde solution in order to enhance their mechanical properties and also make them insoluble in water. Diffusion of calcium and phosphate ions from lateral sides into the hydrogel middle caused formation of a white layered precipitate. Analysis of precipitates formed within the hydrogel middle for the samples showed that detected materials are composed of carbonated hydroxyapatite and amorphous dicalcium phosphate dihydrate. After incubation in simulated body fluid, the amorphous phase converted to crystalline hydroxyapatite, which process is similar to bone formation in the human body. Mechanical properties obtained for the scaffolds were comparable to spongy bone. Also in this work, MTT assay and alkaline phosphatase activity on the prepared scaffolds were evaluated and discussed. Finally, the obtained experimental results ascertained that the nanocomposite prepared with chitosan/gelatin (20/80) had appropriate properties for bone tissue engineering scaffold.

Chemical Constituents with Immunological Activities from the Barks of Platanus acerifolia

Platanus acerifolia (Aiton) Willd. (Platanaceae) is a hybrid of P. orientalis and P. occidentalis. P. acerifolia is highly resistant to powdery mildew and atmospheric contamination, so it is often used for landscaping and street planting. P. acerifolia was also used to treat toothache, dysentery and diarrhea in folk medicine and has rich resources. Studies have indicated that P. acerifolia consists mainly of the chemical constituents of flavonoids, triterpenes, tannins, and long-chain fatty compounds and possesses antibacterial, anti-HIV, antitumor, and uncoupling activity [1–4]. The 95% alcohol extract of the deciduous barks of P. acerifolia was separated by column chromatography on silica gel to yield compounds 1–6, which were individually identified as 3-acetylbetulinic aldehyde (1), betulonic acid (2), betulinic acid (3), daucosterol (4), 3,4,5-trimethoxyphenyl-O-D-glucopyranoside (5), and 3,4,5-trimethoxyphenyl-O-Dglucopyranoside-6 -sulfate sodium (6) by comparison of their spectral data to those reported in the literature [5, 6]. Compound 6 was obtained as a colorless granular crystalline powder. Its molecular formula was established as C15H21O12SNa by HR-ESI-MS at m/z 425.0759 [M – Na]– and 471.0543 [M + Na]+. Its 1H and 13C NMR spectra were typical of a glycoside of 3,4,5-trimethoxyphenol. The 13C NMR spectral data of the sugar moiety of 6 were consistent with those of glucose, except that the chemical shift of C-6 of 6 was shifted downfield by 5.0 ppm, which suggested compound 6 was the 6 -O-substituted glucopyranoside. The IR spectrum of 6 showed intense absorption at 1259 cm–1 and 814 cm–1, attributed to the stretching of the S=O bond and C–O–S bonds on the sulfate ester, and acid hydrolytic reaction gave sulfates (white precipitate with BaCl2), which indicated 6 is a glucosidal sulfate ester. 2D NMR including HMQC and HMBC experiments allowed us to assign all the proton and carbon signals of 6. 1H NMR (500 MHz, DMSO-d6, , ppm, J/Hz): 6.38 (s, H-2, 6), 3.75 (6H, s, CH3O-3, 5), 3.59 (3H, s, CH3O-4), 4.72 (d, J = 7.5, H-1 ), 3.21 (m, H-2 ), 3.23 (m, H-3 ), 3.06 (m, H-4 ), 3.53 (m, H-5 ), 4.15 (m, H-6 a), 3.68 (m, H-6 b), 5.23 (d, J = 5.0, 2 -OH), 5.07 (d, J = 4.5, 3 -OH), 5.10 (d, J = 5.5, 4 -OH). 13C NMR (125 MHz, DMSO-d6, , ppm): 154.2 (C-1), 94.5 (C-2, 6), 153.3 (C-3, 5), 132.6 (C-4), 101.3 (C-1 ), 73.4 (C-2 ), 76.7 (C-3 ), 70.5 (C-4 ), 75.1 (C-5 ), 66.1 (C-6 ). Thus, the structure of compound 6 was determined as 3,4,5-methoxyphenol-1-O-Dglucopyranoside-6 -sulfate sodium. Phenol glycoside and sulfate occur freely in Adiantum species of the family Adiantaceae [7], but this is the first report of their occurrence in the family Platanaceae.

The case for reprecipitation of human bone as an event in a Bronze Age cist burial, Scotland

A hard whitish precipitate was observed on the lower part of the sandstone sidewalls and as pebble coatings in a Bronze Age cist burial near Forteviot, Strathearn, Scotland. The cist was discovered on excavation of a Neolithic henge in August 2009 during the joint Glasgow and Aberdeen Universities [Strathearn and Environs Royal Forteviot (SERF)] archaeological landscape research project and summer field school. Similar cists have not been found in this area. Scrapings of the precipitate proved on examination by powder X-ray diffraction to be hydroxyapatite. The mamillary material proved on examination by scanning electron microscopy to be calcium carbonate, calcite which had grown as groups of mm-size spheroids consisting of bundles of acicular crystals. Both components of the precipitate were also identified using oil immersion microscopy. Much organic material was preserved in the cist but neither (inorganic) bone nor teeth has been located to date (November 2010). The phosphatic mineral-precipitates provided the first confirmation that there had been bone and therefore an inhumation. Computational aqueous geochemistry using Geochemist’s Workbench confirms that the inorganic calcium phosphate component of human bone is soluble in acidic fluid and demonstrates how it can reprecipitate with change in fluid chemistry. Bone dissolution should be anticipated as being an expected early process when a human body produces an acidic fluid rich in organic molecules as it decays in an essentially closed, but wet, anoxic environment. Any precipitates on grave stonework should be identified as such material could represent human remains and could also provide evidence of environmental processes in the archaeological setting of a burial.

Loop-Mediated Isothermal Amplification Assays for DetectingYersinia pseudotuberculosisin Milk Powders

Yersinia pseudotuberculosis is a Gram-negative foodborne pathogen that causes several diseases, such as enteritis, septicemia, and reactive arthritis. Loop-mediated isothermal amplification (LAMP) assay targeting the 16S-23S rDNA internal transcribed spacer (ITS) region was developed to detect Y. pseudotuberculosis in milk powder. The DNA amplification could be completed in 1 h, and detected by produced white precipitate visible to naked eyes. The detection limit of LAMP assay was 10(0) fg/reaction for genomic DNA, and 10(0) CFU/100 g milk powder coupled with 12 h enrichment. LAMP assay is 100 times more sensitive than conventional polymerase chain reaction method for detecting Y. pseudotuberculosis, and correctly identified 18 cases of Y. pseudotuberculosis contaminations from 236 commercial milk powder products. In conclusion, the developed LAMP assay may facilitate rapid detection of Y. pseudotuberculosis contaminations in agricultural and food products. Rapid and accurate detection of Yersinia pseudotuberculosis in milk products.

Physical and radiological properties of radiochromic gel as of its composition

In the research, we evaluated the use of leuco crystal violet (LCV) gel as a dosimeter for therapeutic radiation by investigating its optical characteristics at various component concentrations. We also investigated the aging effect of the LCV gel at different beam energies, doserates, and dosing times to evaluate the LCV’s applicability to radiation therapy. We confirmed that the optimal optical wavelength of the LCV gel dosimeter was 600 nm. The dose sensitivity increased with increasing concentration of LCV; however, the optimal concentration was 1 mM LCV because the transparency of the gel dosimeter is important for use in optical CT scanners. However, the dose sensitivity decreased with increasing concentration of trichloroacetic acid (TAA). Moreover, the transparency of LCV rapidly decreased because of the generation of a white precipitate at TAA concentrations below 25 mM. Thus, an optimal TAA concentration of 30 mM was used in this study. Triton X-100 (8 mM) was identified as the optimal reagent for determining the optimum gel transparency and dose sensitivity. Thus, we present an LCV gel dosimeter composed of 4% gelatin by mass, 1 mM LCV, 30 mM TAA, and 8-mM Triton X-100 for use with an optical CT scanner. We showed good dose linearity up to 30 Gy. There was a little doserate dependency at a beam energy of 6 MV while the doserate dependence was more than 4.2% at a beam energy of 10 MV. To evaluate the energy dependence of the LCV gel dosimeter, we irradiated it at 20 Gy by using 6 MV and 10 MV beams. At the high doserate, the difference in the dose energy dependence was relatively small at approximately 1%, but the difference increased to 4.6% at the low doserate. With respect to the radiation absorbance at a photon energy of 6 MV, the absorbance at an electron energy of 6 MeV decreased by 5.4%, and the absorbances at 9, 12, and 15 MeV increased by 3, 18.7, and 12.2%, respectively. Furthermore, the aging effect was larger in the low-dose group then in the high-dose group. Moreover, we observed that the absorbance between 24 and 48 h after irradiation increased by approximately 5% at 5 Gy. For gel groups tested at high doses, the aging effect was reduced by approximately 1%.

Removal of hydrogen sulfide with steelmaking slag by concurrent reactions of sulfide mineralization and oxidation

This study experimentally revealed the entire mechanisms of mineralization and oxidation of H2S by steelmaking slag. After adding steelmaking slag to an artificially prepared H2S solution, white precipitates were generated, and were identified as elemental sulfur by X-ray absorption fine structure spectra. Sulfate ion was also detected in the solution, but in small amounts. In addition, FeS was identified on the surface of the steelmaking slag. An increase in the oxidation–reduction potential implies the oxidation of H2S by the steelmaking slag, resulting in the formation of oxidized sulfur compounds. We confirmed that steelmaking slag can effectively remove H2S through oxidation as well as through its mineralization to FeS and that these processes are promoted by both Fe and Mn originating from the slag.

Proposed Cross-Linking Model for Carboxymethyl Cellulose /Starch Superabsorbent Polymer Blend

Superabsorbent polymer (SAP) blend has been synthesized from Carboxymethyl Cellulose (CMC) , starch, and aluminum sulfate octadecahydrate cross-linker. Water Absorption Capacity (WAC), FTIR, SEM, DSC, CHO, Flame Photometer and ignition tests are carried out to determine the used CMC formula, investigate the cross-linking process, and suggest a cross-linking model. Flame Photometer results showed there are two sodium acetate groups in the CMC molecule. This result confirmed by theoretical calculations and CHO test . To investigate which of Al3+ and SO42- ions causes the cross-linking : the extraction of the cross-linked CMC/starch tested with BaCl2solution(showed dense white precipitate ; sulfate group not share for blend formation), NaOH solution( showed white precipitate of aluminum hydroxide; Al3+ ion present (i.e. Al3+ ion share in the blend structure). These results confirmed by flame test for sodium ion, which showed high Na emission energy (5.75); there is an exchange between Al and Na ions. To check that aluminum is a part of the structure, sample of the cross-linked CMC ignited. A white precipitate appear for aluminum oxide ,which confirms the presence of Al. Based on that there are three CMC molecules connected to each Al atom, theoretical calculations about the amount of Al in the cross-linked CMC molecule showed a good agreement with the CHO results (5.613% Vs. 5.739 % respectively). FTIR spectrum of the cross-linked CMC/starch blend showed that there is a reaction between CMC and starch molecules; i.e. the new repeating unit contains three starch molecules. This conclusion confirmed by theoretical calculations and results of EDX, CHO, and ignition tests. Al% in the new mer appeared a good agreement between theoretical calculations (4.32%) and CHO results (4.512%). Ignition test calculations confirmed that the new mer contains three Al atoms. Evidences of the occurrence of the cross-linking process were obtained from FTIR, morphology, DSC and absorbency results. Absence of the primary hydroxyl alcohol band in the CMC/starch blend spectrum, indicates that this site is active and the reaction between starch and CMC molecules occurs through it. Morphologies studies showed that the sample after crosslinking is more compact than before as well as show one piece for after cross-linking comparing with different pieces before cross-linking.Optimum cross-linking ratio appeared to be 2wt% corresponded to WAC equal to 58 g/g.in distilled water and DSC results indicates that CMC/starch is a miscible blend.

Hydrothermal Synthesis of LaCO3OH and Ln3+-doped LaCO3OH Powders under Ambient Pressure and Their Transformation to La2O2CO3and La2O3

mol) of urea were dissolved in 50 mL of a mixedsolvent of ethylene glycol (EG) and water. EG to watervolume ratios were 9:1, 8:2, 7:3, 6:4, 5:5, 2:8, and 0:10. Thesolution was boiled for 24 h under ambient pressure andcooled to room temperature. Sequentially, the white pre-cipitate was separated by centrifugation, washed severaltimes with water and ethyl alcohol, and dried in an oven at70

Low Temperature Synthesis of α-Alumina with a Seeding Technique

This paper reports a method for producing α-Al2O3 at low temperature, which uses a seeding technique. White precipitate of aluminum hydroxide, which was prepared with a homogeneous precipitation method using aluminum nitrate and urea in aqueous solution, was peptized by using acetic acid at room temperature and then transformed to a transparent alumina sol. To the alumina sol α-Al2O3 particles were added as a seed, and then the sol containing α-Al2O3 particles was transformed to an α-Al2O3-seeded alumina gel by drying the sol at room temperature. The nonseeded alumina gel was amorphous or fine crystallites even after being annealed at 600°C and was crystallized to γ-Al2O3 at 700°C. The α-Al2O3 seeding promoted crystallization of alumina gel to α-Al2O3. The promotion of crystallization was made remarkable with a decrease in α-Al2O3 particle size and an increase in α-Al2O3 particle content in weight for the final seeded alumina gel. With an α-Al2O3 particle size of 150 nm and an α-Al2O3 particle content of 5%, the seeded alumina gel was partially crystallized to α-Al2O3 by annealing at a temperature as low as 700°C and mostly at 900°C.

Synthesis of Nano Calcium Phosphate via Biomimetic Method for Bone Tissue Engineering Scaffolds and Investigation of its Phase Transformation in Simulated Body Fluid

In this study the formation of calcium phosphate phase via double diffusion method into a hydrogel matrix was investigated and its phase transformation in simulated body fluid was studied. White precipitate was formed within the hydrogel, due to the diffusion of calcium and phosphate ions through the hydrogel matrix in similar pH to human body. Phase composition, microstructure and structural groups in the composite samples were also characterized by X-Ray Diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infra-red (FTIR) analyses. Microstructure of precipitates formed within middle hydrogel, showed that detected materials are composed of carbonated hydroxyapatite and dicalcium phosphate dihydrate (DCPD, brushite). The particle size was about 10 nm .Analysis results showed that after incubation in simulated body fluid, dicalcium phosphate dehydrate phase transformed into crystalline hydroxy apatite.

Reinvestigation of the Synthesis of Ketanserin (5) and its Hydrochloride Salt (5.HCl) via 3‐(2‐Chloroethyl)‐2,4‐(1H,3H)‐quinazolinedione (2) or Dihydro‐5H‐oxazole(2,3‐b)quinazolin‐5‐one (1)

The synthesis of ketanserin (5) and its hydrochloride salt (5.HCl) using respectively equimolar amounts of 3‐(2‐chloroethyl)‐2,4‐(1H,3H)‐quinazolinedione (2) with 4‐(parafluorobenzoyl)piperidine (3) and dihydro‐5H‐oxazole(2,3‐b)quinazolin‐5‐one (1) with hydrochloride salt of 4‐(parafluorobenzoyl)piperidine (3.HCl) is reinvestigated. The one‐pot reaction of ethyl‐2‐aminobenzoate with ethyl chloroformate and ethanol amine has afforded 3‐(2‐chloroethyl)‐2,4‐(1H,3H)‐quinazolinedione (2) (86%) that was then refluxed with 4‐(parafluorobenzoyl)piperidine (3) in ethyl methyl ketone in the presence of sodium carbonate to obtain free base of ketanserin (87%). In another attempt, a very pure hydrochloride salt of ketanserin (5.HCl) was synthesized using equimolar amounts of dihydro‐5H‐oxazole(2,3‐b)quinazolin‐5‐one (1) and hydrochloride salt of 4‐(parafluorobenzoyl)piperidine (3.HCl) by a solvent‐less fusion method. Thus, under optimized conditions, 180°C and a reaction time of 30 min, the powder mixture was transformed into glassy crystals that were initially readily soluble in chloroform but were transformed afterwards over time (2 h) to white precipitates (5.HCl) suspended in chloroform with a yield of 72%.

Novel Spot Tests for Detecting the Presence of Zinc Sulfate in Urine, a Newly Introduced Urinary Adulterant to Invalidate Drugs of Abuse Testing

To find a suitable method for detecting zinc sulfate in adulterated urine. Two rapid spot tests to detect the presence of zinc sulfate in urine were developed. Addition of 3 to 4 drops of 1N sodium hydroxide solution to approximately 1 mL of urine containing zinc sulfate led to the formation of a white precipitate, which was soluble in excess sodium hydroxide. In the second spot test, addition of 3 to 4 drops of 1% sodium chromate solution to 1 mL of urine containing zinc sulfate followed by the addition of 4 to 5 drops of 1N sodium hydroxide led to formation of a yellow precipitate (zinc chromate). Detection limit of these visual spot tests was 10 mg/mL of zinc sulfate in urine. Twenty drug-free urine specimens and urine containing high amounts of sugar or reducing substances were tested with no false-positive spot test results observed. However, if lead is present in high amounts in urine, it may cause false-positive spot test results. When aliquots of urine controls for drugs of abuse testing were supplemented with different amounts of zinc sulfate, false-negative drug test results were observed except for amphetamine. Zinc sulfate also falsely reduced measured urine alcohol level in urine. Zinc sulfate can invalidate urine drug and alcohol testing but can be detected using the novel spot tests developed.

Preparation of Protein-like Silver–Cysteine Hybrid Nanowires and Application in Ultrasensitive Immunoassay of Cancer Biomarker

Novel protein-like silver-cysteine hybrid nanowires (p-SCNWs) have been synthesized by a green, simple, nontemplate, seedless, and one-step aqueous-phase approach. AgNO3 and l-cysteine were dissolved in distilled water, forming Ag-cysteine precipitates and HNO3. Under vigorous stirring, the pH of the solution was rapidly adjusted to 9.0 by addition of concentrated sodium hydroxide solution, leading to quick dissolution of the Ag-cysteine precipitates and sudden appearance of white precipitates of p-SCNWs. The p-SCNWs are monodispersed nanowires with diameter of 100 nm and length of tens of micrometers, and have abundant carboxyl (-COOH) and amine (-NH2) groups at their surfaces, large amounts of peptide-linkages and S-bonding silver ions (Ag(+)) inside, making them look and act like Ag-hybrid protein nanostructures. The abundant -COOH and -NH2 groups at the surfaces of p-SCNWs have been found to facilitate the reactions between the p-SCNWs and proteins including antibodies. Furthermore, the fact that the p-SCNWs contain large amounts of silver ions enables biofunctionalized p-SCNWs to be excellent signal amplifying chemiluminescence labels for ultrasensitive and highly selective detection of important antigens, such as cancer biomarkers. In this work, the immunoassay of carcinoembryonic antigen (CEA) in human serum was taken as an example to demonstrate the immunoassay applications of antibody-functionalized p-SCNWs. By the novel p-SCNW labels, CEA can be detected in the linear range from 5 to 400 fg/mL with a limit of detection (LOD) of 2.2 fg/mL (at signal-to-noise ratio of 3), which is much lower than that obtained by commercially available enzyme-linked immunosorbent assay (ELISA). Therefore, the synthesized p-SCNWs are envisioned to be an excellent carrier for proteins and related immunoassay strategy would have promising applications in ultrasensitive clinical screening of cancer biomarkers for early diagnostics of cancers.

Synthesis of Silver-Doped Zinc Oxide Nanocomposite by Pulse Mode Ultrasonication and Its Characterization Studies

The synthesis of silver-doped zinc oxide (Ag:ZnO) nanocomposite material was achieved using a simple chemical coprecipitation method, in which 0.2 M zinc chloride and 0.001 M silver nitrate coprecipitated with 25% ammonia solution by pulse mode dispersion using ultrasonicator. The obtained silvery white precipitate was dried overnight at 110°C in hot air oven, and the powder was collected. The resulted Ag:ZnO nanocomposite was structurally and optically characterized using various techniques. The X-ray diffraction (XRD) pattern clearly showed the presence of crystalline Ag:ZnO particles. Further, UV-Vis spectrophotometer and fourier transform infrared spectroscopy (FT-IR) results showed the presence of Ag:ZnO nanocomposite at specific wavelengths. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis confirm that the synthesized Ag:ZnO nanocomposite material was truncated nanorod in shape and has 48 to 226 nm size in diameter.

A rapid and sensitive method for field detection of Prorocentrum donghaiense using reverse transcription-coupled loop-mediated isothermal amplification

Prorocentrum donghaiense is the most common bloom-forming species in the East China Sea, causing serious damage to regional marine ecosystems, marine fisheries, public health, and aquatic environment. To minimize fisheries losses caused by this harmful alga, a simple and accurate detection method need to be developed to provide adequate early warning for P. donghaiense blooms. In this study, we report the development and application of reverse transcription-coupled loop-mediated isothermal amplification (RT-LAMP) in the field detection of P. donghaiense. The partial large subunit rDNA (LSU D1–D2), small subunit rDNA, and internal transcribed spacers of P. donghaiense were first sequenced to design species-specific amplification primers. Primer set screen showed that the LSU D1–D2 was the best target for LAMP in terms of sensitivity and stability. The amplification conditions including the dNTP and betaine concentrations, the inner primer to outer primer concentration ratio, reaction time, and temperature, were optimized. The specificity of RT-LAMP for P. donghaiense was also confirmed through tests using a few common harmful algae. RT-LAMP targeting RNA exhibited a detection limit of 0.6 cells, which is more sensitive than LAMP and PCR targeting DNA and reverse transcription-polymerase chain reaction (RT-PCR) targeting RNA. Finally, an improved protocol for natural samples was applied to the field material. The optimized detection protocol could be completed within 1h. In addition, positive RT-LAMP results could be confirmed through the production of white magnesium pyrophosphate precipitate or through mixing the fluorescent dye GeneFinder™ with the amplification products. In summary, the established RT-LAMP is specific, sensitive, and rapid method that is promising for the field detection of P. donghaiense.

Synthesis and Characterization of TiO<sub>2</sub> Nanoparticle Using Starch as a Template by Sol-Gel Method for the Application of UV Protection

Nanotechnology is one of the key technology had been developed since in all fields including textile industries for medical, hygienic, and technical textiles. Particle size with nanohad been indicated in particular for the application of controlled release material for functional textiles. TiO2 nanopowder has remarkable photo-catalytic and semiconductor as material for various advanced technology fields of application such as UV Protection. In this research the synthesis of TiO2 nanoparticle and characterization had been conducted successfully by sol-gel method. The starch was used as a template to get nanoparticles structure. TiO2 sol with narrow particle size distribution using TiCl4 as the starting material. The sol was prepared by a process where HCl was added to a gel of hydrated titanium oxide to dissolve it. The effect of preparation parameters were investigated, by deionized water : HCl 1 M was slowly added to TiCl4 at 5 °C. In this study the production of anatase or rutile TiO2 nanostructured powder by forced hydrolysis of aqueous Ti (IV) chloride solution and concentration from 0,3, 0,5 then 1 M. TiO2 sphere were fabricated by a facile and low cost stable starch assisted by sol-gel method. Aqueous solution of starch was added and then heated in temperature 80°C and aqueous solution of ammonium hydroxide was added to adjust pH to 8. After aging period of time, the white precipitate was filtered and then calcined in temperature 5000 C. The as-obtained samples were characterize,kjnhjd by SEM (Scanning Electron Microscope), UV-vis diffuse reflectance spectroscopy, X-Ray Diffraction (XRD) and Brunauer Emmett Teller (BET) analysis. The particle size is less than 100 nm and if it uses template particle TiO2 more uniform distribution and spherical shape with particle size 170 200 nm. Crystalinity particle is 4 19 nm and the phase structure of anatase and rutile. The energy band gap semiconductor TiO2 synthesis is 3.1 to 3.7 eV. Surface area without template starch 40.655 m2/g, with total for volume 0.278 cm3/g and pore size of 27 nm, and used template starch surface area 35.488m2/g with total for volume 0.196 cm3/g and pore size of 22 nm. Based on this research, the best a crystal phase for UV protection application is rutile phase.

Synthesis and Characterization of TiO<sub>2</sub> Nanoparticle Using Starch as a Template by Sol-Gel Method for the Application of UV Protection

Nanotechnology is one of the key technology had been developed since in all fields including textile industries for medical, hygienic, and technical textiles. Particle size with nanohad been indicated in particular for the application of controlled release material for functional textiles. TiO2 nanopowder has remarkable photo-catalytic and semiconductor as material for various advanced technology fields of application such as UV Protection. In this research the synthesis of TiO2 nanoparticle and characterization had been conducted successfully by sol-gel method. The starch was used as a template to get nanoparticles structure. TiO2 sol with narrow particle size distribution using TiCl4 as the starting material. The sol was prepared by a process where HCl was added to a gel of hydrated titanium oxide to dissolve it. The effect of preparation parameters were investigated, by deionized water : HCl 1 M was slowly added to TiCl4 at 5 °C. In this study the production of anatase or rutile TiO2 nanostructured powder by forced hydrolysis of aqueous Ti (IV) chloride solution and concentration from 0,3, 0,5 then 1 M. TiO2 sphere were fabricated by a facile and low cost stable starch assisted by sol-gel method. Aqueous solution of starch was added and then heated in temperature 80°C and aqueous solution of ammonium hydroxide was added to adjust pH to 8. After aging period of time, the white precipitate was filtered and then calcined in temperature 5000 C. The as-obtained samples were characterize,kjnhjd by SEM (Scanning Electron Microscope), UV-vis diffuse reflectance spectroscopy, X-Ray Diffraction (XRD) and Brunauer Emmett Teller (BET) analysis. The particle size is less than 100 nm and if it uses template particle TiO2 more uniform distribution and spherical shape with particle size 170 200 nm. Crystalinity particle is 4 19 nm and the phase structure of anatase and rutile. The energy band gap semiconductor TiO2 synthesis is 3.1 to 3.7 eV. Surface area without template starch 40.655 m2/g, with total for volume 0.278 cm3/g and pore size of 27 nm, and used template starch surface area 35.488m2/g with total for volume 0.196 cm3/g and pore size of 22 nm. Based on this research, the best a crystal phase for UV protection application is rutile phase.

SULFONATED ORDERED NANOPOROUS CARBON AS AN EFICIENT SOLID CATALYST FOR THE SYNTHESIS OF PERIMIDINE DERIVATIVES

Sulfonated ordered nanoporous carbon (CMK-5-SO 3 H) efciently catalyzes the synthesis of perimidines using cyclocondensation of various aldehydes and ketones with 1,8-diaminonaphthalene in ethanol as a solvent at room temperature. This catalyst can be recovered and reused without significant loss of activity. This methodology provides a simple synthetic route to interesting classes of heterocycles in excellent yields at short time. Key word: sulfonated ordered nanoporous carbon, heterogeneous catalyst, perimidine, aldehyde, ketone, 1,8-diaminonaphthalene. 1 . Numbers of methods have been developed for the synthesis of perimidines involving the condensation of 1,8-diaminonaphthalene with various carbonyl compounds 2-10 . Despite efficiency of several published methods, some of these procedures suffer from disadvantages such as long reaction time, use of non reusable catalyst and limitation in the use of ketone as a substrate. Therefore, it seems that there is much room for the development of new protocols to overcome these problems. The use of heterogeneous solid catalysts in the organic synthesis and industrial reactions is interesting due to their suitable acidity, thermal stability, selectivity and reusability; they also provide a green alternative to homogeneous catalysts 11 . Among the diferent types of heterogeneous catalysts, recently, Wang and his co-workers prepared a novel sulfonic functionalized ordered mesoporous carbon (CMK-5-SO 3 H) that has high surface area, high loading and uniform nanostructure 12 . However, to the best of our knowledge, there is no report available on the synthesis of perimidine derivatives using CMK-5-SO 3 H catalysts in the open literature. Herein, we report a simple, convenient, and efficient method for the synthesis of perimidine derivatives by cyclocondensation of various aldehydes and ketones with 1, 8-diaminonaphthalene in the presence of CMK-5-SO 3 H as a reusable and eco-friendly catalyst (Scheme 1). composite was filtrated and washed with EtOH and acetone to remove excess and unpolymerized FA. The obtained composite was heated to 850 °C under vacuum at a ramp of 10 °C/min for 3 h to carbonization. Ordered mesoporous carbon (CMK-5) was obtained by removal of silica by HF (10 % in 1 : 1 EtOH - H 2 O), washed with copious water and EtOH, and dried at 100 °C. For the sulfonation of CMK-5, initially 4-benzenediazoniumsulfonate was synthesized by diazotization of p-sulfanilic acid. Solution of NaNO 2 (1 M) was slowly added to a mixture of 12.99 g of p- sulfanilic acid (0.075 mol) and 7.5 g HCl (1 M) at 3-5°C in order to option the clear solution and then the mixture was stirred for 45 min. The white precipitate formed was filtered off, washed by cold water, and dried under reduced pressure. In a typical modification, 1.2 g of CMK-5 was added in a mixture of 12.0 g of 4-benzenediazoniumsulfonate, 200 ml of distilled water and 200 ml of ethanol. Subsequently, the mixture was cooled down to 5 °C and 200 ml of 50 wt % H 3 PO 2 aqueous solution was added. After stirring for 30 min, another 200 ml of H 3 PO 2 aqueous solution was added and stirred at 5 °C for 30 min. Finally CMK-5-SO 3 H was filtered off, washed with distilled water and acetone, and dried in an oven at 80 °C. The amount of acid in CMK-5-SO 3 H was determined by thermogravimetric analysis (TGA) and ion-exchange pH analysis. Typically a loading of ca. 0.84 mmol/g was obtained. 1. 2 General procedure for the synthesis of perimidines A mixture containing 1,8-diaminonaphthalene (1.0 mmol), carbonyl compound (1.0 mmol) and CMK-5-SO 3 H (0.011 g: 1 mol%) in ethanol (3 mL) was stirred at room temperature for the appropriate time according to Table 2. (The progress of reaction was monitored by TLC). After completion of the reaction, catalyst was separated by filtration. Then water was added to the filtrate (3-5 mL) and the mixture was filtered and the precipitate washed with water and dried. The structure of products was characterized by spectral data (1H NMR and 13C NMR) and physical properties and comparison with

Segregation of Elements in Corrosion Resistant Castings of Diversified Wall Thickness

Abstract The segregation of elements in two corrosion resistant cast steel grades Cr18-Ni9-Mo, in castings of wall thickness: 7, 15 and 30 mm were performed. The results indicate the analogous path of curves of the content of Fe, Cr, Ni, Mo and C, in walls of various thickness. Decrease in the content observed in the delta ferrite Fe (2 to 3 wt. %), Ni (from 3.5 to 5 wt. %) and C (about 1 wt. %), where the Mo and Cr increased their content of 2% wt. %, and about 6% wt. respectively in the case of the two test cast. For the test steel Q2 with a carbon content 0.054 wt. % were found carbides in the form of white precipitates on the grain boundary of delta ferrite. This resulted in the occurrence of the peaks in the lines of the element distribution analysis especially for molybdenum, iron and carbon, as shown in the diagrams for various segregation of wall thickness.