Amount Of Barium Research Articles

Hydrothermal synthesis of multiferroics ferrite bismuth nanoparticles with lanthanum and barium: Structural and magnetic properties investigation

In this work, Bi1-xLaxFeO3 (BLFO) and Bi0.9-YLa0.1BaYFeO3 (BLBaFO) nanoparticles were synthesized by different amounts of barium and lanthanum in ferrite bismuth (x = 0, 0.05, 0.1, 0.15, Y = 0.05, 0.1) using the hydrothermal method in the presence of crosin as a natural surface activator based on sugar. Then, structural, magnetic, size and morphological properties of synthetic nanoparticles were investigated using Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), Transmission Electron Microscope (TEM), Scanning Electron Microscope (FE-SEM), Dynamic Light Scattering (DLS) and Vibrating Sample Magnetometer (VSM). XRD showed that by increasing the concentration of lanthanum and barium perforated in ferrite bismuth, a phase change occurred from rhombohedral structure to tetragonal. The presence of tensile vibrations in the zone of 400–600 cm−1 associated with Fe-O, Bi-O, and Ba-O bonds in the FT-IR confirmed the production of these nanoparticles. TEM images for Bi0.9La0.1FeO3 nanoparticles showed the particle size of about 25 nm and uniformity in morphology, and the existence of approximately spherical structures. The optimum magnetic performance was observed when the amount of lanthanum inserted in bismuth ferrite in the presence of surface activator crocin was x = 0.1 in stoichiometry. Also, the effect of various natural surface activators based on sugar such as saponin, Triton CG-100, crocin and N-acetyl-beta-d-glucoside were investigated by DLS.

Synthesis of metastable Ruddlesden–Popper titanates, (ATiO3)n AO, with n ≥ 20 by molecular-beam epitaxy

We outline a method to synthesize (ATiO3)nAO Ruddlesden–Popper phases with high-n, where the A-site is a mixture of barium and strontium, by molecular-beam epitaxy. The precision and consistency of the method described is demonstrated by the growth of an unprecedented (SrTiO3)50SrO epitaxial film. We proceed to investigate barium incorporation into the Ruddlesden–Popper structure, which is limited to a few percent in bulk, and we find that the amount of barium that can be incorporated depends on both the substrate temperature and the strain state of the film. At the optimal growth temperature, we demonstrate that as much as 33% barium can homogeneously populate the A-site when films are grown on SrTiO3 (001) substrates, whereas up to 60% barium can be accommodated in films grown on TbScO3 (110) substrates, which we attribute to the difference in strain. This detailed synthetic study of high n, metastable Ruddlesden–Popper phases is pertinent to a variety of fields from quantum materials to tunable dielectrics.

Waste paper ash as a hydraulic road binder: Hydration, mechanical and leaching considerations

Waste paper fly ash (WPFA) and bottom ash (WPBA), derived from fluidised bed combustion of a paper recycling plant, exhibit cementitious properties owing to its mineralogical composition, and hence, could be proposed as a hydraulic binder. However, it may also contain some traces of heavy metals. Considering it is necessary to understand the effect of reusing any kind of waste on the environment, this study proposes of reusing WPFA/WPBA as a hydraulic road binder by evaluating its mineralogical composition and leaching activity. Chemical, physical, and mineralogical properties of raw WPFA/WPBA and the microstructural evolution of binders were carried out. Results showed that both ashes undergo hydration reactions while showing some cementitious properties by forming C–S–H gel, Friedel's salt, and calcite. According to the European standard EN 13282–1, both WPFA and WPBA can be categorised as N1 considering they reach 5.3 and 3.6 MPa, respectively, at 56 days. Furthermore, the mechanical performance of various soils was improved by using WPFA and WPBA as a binder. From the environmental point of view, the amount of barium in WPFA and WPBA, which is the main problem, was significantly decreased by using these ashes as a binder.

Synthesis of barium-doped PVC/Bi2WO6 composites for X-ray radiation shielding

In this study, composites containing undoped and barium-doped Bi2WO6:Ba2+were investigated for their shielding against diagnostic X-ray. At first, Bi2WO6 and barium-doped Bi2WO6 were synthesized with different weight percentages of barium oxide through a hydrothermal process. The as-synthesized nanostructures were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and Raman spectroscopy (RS). After that, some shields were generated with undoped and barium-doped Bi2WO6:Ba2+ nanostructure particles incorporated into polyvinyl chloride (PVC) polymer with different thicknesses and 15% weight of the nanostructure. Finally, the prepared samples were exposed to an X-ray tube at 40, 80, and 120 kV voltages, 10 mAs and, 44.5 cm SID (i.e. the distance from the X-ray beam source to the specimen). Linear and mass attenuation coefficients were also calculated for different samples. The results indicated that, among the samples, the one with 7.5 mmol barium-doped Bi2WO6 had the most attenuation at the voltage of 40kV, and the attenuation coefficients would increase with an increase in the amount of barium. The samples with 15 and 17.5 mmol barium-doped Bi2WO6 had higher attenuation than the others at 80 and 120 kV. Moreover, the half-value layer (HVL), tenth-value layer (TVL) and 0.25 mm lead equivalent thickness were calculated for all the samples. The lowest HVL value was for the sample with 7.5 mmol barium-doped Bi2WO6. As the result clearly show, an increment in the barium-doping content leads to a decrease in both HVL and TVL.In every three voltages, 0.25 mm lead equivalent thickness of the barium-doped composites (7.5 mmol and 15 mmol) had less than the other composites. The lowest value of 0.25 mm lead equivalent thickness was 7.5 barium-doped in 40 kV voltage and 15 mmol barium-doped in 80 kV and 120 kV voltages. These results were obtained only for 15% weight of the nanostructure.

The neutron cross section of barite-enriched concrete for radioprotection shielding in the range 1 meV–1 keV

We present a characterization of a series of barite-enriched concrete samples at the atomic scale using neutron-based techniques. In particular, neutron transmission measurements provide the macroscopic cross section (also known as neutron removal cross section) as a function of the incident neutron energy in the range 1 meV–1 keV. In this range, where fewer experimental investigations are available in the literature, the cross section is dominated by the scattering events from hydrogen, as opposed to the fast-neutron region (MeV-energy neutrons) where capture events by Ba are more important. Moreover, below 1 eV, the cross section depends on the molecular or crystal structure of the components. For each sample, the amounts of barium and hydrogen are provided by neutron resonance capture analysis and deep inelastic neutron scattering, respectively. We find that the amounts of barium and hydrogen are correlated, with a lower amount of hydrogen in the samples with more barium, likely because of the absence of some calcium-silicon-hydrate structures, whose formation is inhibited by the presence of barite. Moreover, we quantify the non-negligible contribution to the neutron macroscopic cross section arising from water molecules loosely bound in concrete. This contribution makes the shielding performance of concrete dependent upon the humidity and temperature conditions affecting the installation. Our results provide additional guidelines for radioprotection workers to determine the optimal concentration of barite in mixed gamma/neutron radiation environments.

Characterization of feed coals and coal combustion byproducts from the Wyodak-Anderson coal zone, Powder River Basin, Wyoming

The U.S. Geological Survey (USGS) determined the physical and chemical properties of more than 260 feed coal and coal combustion byproducts from two coal-fired power plants. These plants utilized a low-sulfur (0.23-0.47 wt. % S) and low ash (4.9-6.3 wt. % ash) subbituminous coal from the Wyodak-Anderson coal zone in the Tongue River Member of the Paleocene Fort Union Formation, Powder River Basin, Wyoming. Fifty-three samples of bituminous coal were collected and analyzed from a Kentucky power plant, which used several sources of bituminous coals from the Appalachian and Illinois Basins. Based on scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses of feed coal samples collected and analyzed from 1996 through the late 2000s, two mineral suites were identified: (1) a primary or detrital suite consisting of quartz (including beta-form grains), biotite, feldspar, and minor zircon; and (2) a secondary authigenic mineral suite containing alumino-phosphates (crandallite and gorceixite), kaolinite, carbonates (calcite and dolomite), quartz, anatase, barite, and pyrite. The detrital mineral suite is interpreted, in part, to be of volcanic origin, whereas the authigenic mineral suite is interpreted, in part, to be the result of the alteration of the volcanic minerals. The mineral suites have contributed to the higher amounts of barium, calcium, magnesium, phosphorus, sodium, strontium, and titanium in the Powder River Basin feed coals in comparison to eastern US coals. XRD analysis indicates that (1) fly ash is mostly aluminate glass, perovskite, lime, gehlenite, quartz, and phosphates with minor amounts of periclase, anhydrite, hematite, and spinel group minerals; and (2) bottom ash is predominantly quartz, plagioclase (albite and anorthite), pyroxene (augite and fassaite), rhodonite, and akermanite, and spinel group minerals. Microprobe and SEM analyses of fly ash samples revealed quartz, zircon, and monazite, euhedral laths of corundum with merrillite, hematite, dendritic spinels/ferrites, wollastonite, and periclase. The abundant calcium and magnesium mineral phases in the fly ash are attributed to the alteration of carbonate, clay, and phosphate minerals in the feed coal during combustion. The calcium- and magnesium-rich and alumino-phosphate mineral phases in the coal combustion byproducts can be attributed to volcanic minerals deposited in peat-forming mires. Dissolution and alteration of these detrital volcanic minerals occurred either in the peat-forming stage or during coalification and diagenesis, resulting in the authigenic mineral suite. The presence of free lime (CaO) in fly ash produced from Wyodak-Anderson coal acts as a self-contained “scrubber” for SO3, where CaO + SO3 form anhydrite either during combustion or in the upper parts of the boiler. Considering the high lime content in the fly ash and the resulting hydration reactions after its contact with water, there is little evidence that major amounts of leachable metals are mobilized in the disposal or utilization of this fly ash.

Hydration of clinkers doped with baryte with and without addition of gypsum

The use of alternative fuels and raw materials in cement industry leads to the incorporation of some undesirable compounds into the clinker phases. One of them is barium oxide which influences the formation of clinker phases and related properties of the produced cement. Barium in clinker was already studied; the phase composition is changed depending on the amount of barium. However, detailed research focused on hydration properties of these clinkers and cements has not been carried out, yet. A clinker with barium oxide addition to raw meal was prepared. As a source of barium oxide, barium sulphate (baryte) was used in amount of 4% calculated to BaO in the clinker. Barium incorporated in clinker inhibits formation of alite; therefore, lime saturation factor was slightly reduced. Compared to barium carbonate—another source of barium oxide—barium sulphate influences the ratio of clinker phases less significantly. This clinker and a reference sample without barium were milled with and without addition of gypsum. Hydration of barium clinker and cement was examined by XRD in situ hydration and isothermal calorimetry. Hydration products were evaluated by means of thermogravimetric and differential thermal analysis. An increase in total heat of hydration can be seen in samples with barium. The heat is influenced by different hydration of clinker phases with incorporated barium, sulphates and by higher content of free CaO and C3A. According to XRD in situ hydration, hydration of samples with barium is suppressed, the amount of portlandite during the whole measurement is much higher in samples without barium.

Processing and Electrical Characteristics of Barium Doped CaCu3Ti4O12

In this communication, the effect of a small amount of barium (15%) substitution on structural micro-structural, electrical (dielectric, impedance and conductivity) properties of CaCu3Ti4O12 (i.e., Ca0.85Ba0.15Cu3Ti4O12 = CBCTO15) in different experimental conditions is presented. The polycrystalline sample of the material has been prepared by a cost-effective solid-state reaction technique. Rietveld refinement of XRD data has confirmed that the CBCTO15 sample crystallizes in cubic system bearing space group Im3. The surface micrograph depicts the dense packing of grains. The comprehensive studies of dielectric parameters [relative dielectric constant (er), and loss tangent (tanδ)] are characterized over a wide range of temperature and frequency. The complex impedance and electrical modulus spectroscopy techniques have been employed which postulates the association of various effects (grain, grain boundary, electrode) and shed light on the conduction as well as the relaxation mechanism in the material.

Comparison of Crystal and Phonon Structures for Polycrystalline BaSi<sub>2</sub> Films Grown by SPE Method on Si(111) Substrate

The search for inexpensive and efficient methods of forming thin BaSi2 films as a promising material for photovoltaic is an actual task. The co-deposition of Ba and Si atoms with alloy thickness of 100-120 nm on the silicon substrate at room temperature with following annealing (SPE method) was proposed. Ba-Si alloy compounds then were thermally annealed at different temperatures and three samples were formed: #1 at T = 600 ° C, #2 at T = 700 ° C and #3 at T = 800 ° C. Polycrystalline films with an orthorhombic BaSi2 structure were formed by XRD, UV-VIS, FIR and Raman spectroscopies data. BaSi2 grains in samples #1 and #2 have sizes 62-64 nm and 86 nm in the sample #3 from XRD data calculations by Scherrer formula. Proposed growth method resulted to strong compression of the BaSi2 unit cell volume on 1.78 – 2.70%. The strongest compression was observed after annealing at 800 °C, which was accompanied by desorption of a noticeable amount of barium and a strong decrease in the film thickness in the sample #3. The formation of nanosize Si clusters was confirmed by Raman data for samples #2 and #3, but they did not observed in the sample #3. So, the film, formed at 800 °C, is the most qualitative in terms of structure and single-phase BaSi2, but with strong decrease of initial Ba-Si alloy thickness due to Ba desorption.

An ex vivo comparison of cuffed endotracheal tubes and self-sealing baffled endotracheal tubes

AIMSTo compare cuffed silicone endotracheal tubes with self-sealing baffled silicone endotracheal tubes in an ex vivo canine tracheal model, to determine whether the tubes differed in their maintenance of a seal and their effectiveness in removing fluid from the tracheal lumen, and whether the self-sealing endotracheal tubes would release pressure when a closed anaesthetic circuit reached ≥30 cm H2O.METHODSTwelve cadaver tracheae were randomly selected to be intubated with either cuffed or self-sealing baffled endotracheal tubes. To test tracheal seal efficacy, the tracheae were positioned vertically, 5 mL of water was instilled proximal to the tube cuff or baffles and they were monitored for leakage at 0, 15, 30, 45, and 60 minutes, recording the total volume leaked. To test fluid removal at extubation, the tracheae were intubated, then 5.6 g of 60% barium sulphate suspension was instilled proximal to the seal and left undisturbed for 5 minutes. The tubes were then extubated, with the cuffed endotracheal tubes being partially deflated before extubation, and the amount of barium recovered was weighed. These procedures were repeated on the same tracheae using the other endotracheal tubes. To test whether self-sealing baffled endotracheal tubes would release pressure at ≥30 cm H2O, the tracheae were intubated, connected to an anaesthetic machine and pressurised to 30 cm H2O for 5 minutes and then 50 cm H2O for 5 minutes. Release of pressure was defined as a decrease in pressure within the closed anaesthetic circuit.RESULTSMore cuffed (7/12) than baffled (0/12) endotracheal tubes leaked water after 60 minutes (p=0.016). The mean amount of barium removed by the self-sealing baffled endotracheal tubes (4.9 (95% CI=3.8–4.4) g) was greater than that removed by the partially deflated cuffed endotracheal tubes (0.4 (95% CI=0.14–0.66) g) (p<0.001). None of the self-sealing baffled endotracheal tubes released pressure at ≥30 cm H2O in a closed anaesthetic circuit.CONCLUSIONS AND CLINICAL RELEVANCESelf-sealing baffled endotracheal tubes were more effective than cuffed endotracheal tubes at both preventing fluid leakage at the tracheal seal and removing fluid from the lumen of the trachea in cadaver tracheae. However they did not release pressure when the closed-circuit system was at ≥30 cm H2O in a canine cadaver model. The self-sealing baffled endotracheal tubes may be a suitable substitute for cuffed endotracheal tubes.

Exemption of unnecessary ions from mineral waters, using them to be used for standards and use for medicinal purposes

An important amount of the world’s underground mineral and sheer drinking waters contain excess amounts of various harmful minerals, such as of Barium and Fluorine, the concentrations of which reach - of Barium 5-10 mg/l and Fluorine 5- 15 mg/l, which is why the World Health Organization and sanitary organizations of states and correspondingly the country standards sharply limit the existence of these elements in sheer and mineral waters. The same problems persist in the mineral and sheer drinking waters existing in Georgia. According to standards, the Maximum Acceptable Concentrations (MACs) are overlooked in drinking waters, both sheer and mineral; Ba (barium) - 0,7 mg/l, F (fluorine) - 2 mg/l, in healing drinking mineral waters Fluorine is allowed 3 mg/l. Since the excess of amounts of Barium and Fluorine in sheer and mineral drinking waters does not allow their use and capitalization, the existing multiple drinking and mineral waters in Georgia arc either not used completely or if they are used, that is only with greater restrictions, or more importantly, with special, long-term conditions that not at all satisfy the requirements of domestic and foreign markets. The example of this is provided by the shutting down of the factory of mineral water “Zanavi” because of excess amounts of Fluorine; the inability to master the mineral waters “Gvara” and “Qobuleti” because of the containment of harmful ions in excess amount; the containment of excess amounts of Barium and Fluorine ions in the mineral water “Borjomi” and “Likani” questions the future perspective of the use of this unique drinking mineral waters. The purpose of the project is: through the modification of naturally formed sorbents, the creation and /research of selective sorbents which will have high selectiveness towards the ions of Barium and Fluorine. The treatment of sportive technological process of extraction of Barium and Fluorine ions from sheer and mineral drinking waters until the Maximum Acceptable Concentration. To derive an experimental amount of selective sorbents and to create the appropriate device. To develop technological regulations of the regeneration of sorbents.

The synthesis of Ba2+ doped multiferroic BiFeO3 nanoparticles by using a hydrothermal approach in the presence of different surface activators and the investigation of structural and magnetic features

In this work, Bi1−xBaxFeO3 nanoparticles were synthesized by a hydrothermal method in the presence of various surface activators, and different amounts of barium were inserted in a bismuth ferrite (x = 0.1, 0.15, 0.2) structure instead of bismuth. The structural and magnetic properties, morphology, and size of the synthesized nanoparticles were investigated by XRD, FT-IR, FE-SEM, TEM, DLS and VSM. The XRD analysis results reveal that the synthetic nanoparticles have a single phase. A phase shift from a rhombohedral structure to a tetragonal structure occurs due to the enhanced barium amount in the bismuth ferrite structure. The SEM analysis exhibits a uniform shape of the Bi0.85Ba0.15FeO3 particles and the image observed by TEM clarifies the size of the particles as 11 nm. Furthermore, the effect of the diverse surfaces of activators in the synthesis of Bi0.85Ba0.15FeO3 nanoparticles was studied, revealing that when sugar was used as a surfactant, the particle size reduced and the magnetic properties increased notably.

Pooling of barium at mucosotomy site after peroral endoscopic myotomy on Barium Swallow Study

Peroral endoscopic myotomy (POEM) is a minimally invasive, incisionless alternative to Heller myotomy for treatment of Achalasia. It is still an evolving procedure done only at expert centers. We report an interesting post-procedure radiological finding that might be helpful in managing patients undergoing this procedure. A 24-year-old woman with advanced Achalasia underwent POEM performed in the standard method after which she was kept nil per oral on intravenous antibiotics. Barium swallow study done on the next day showed free passage of barium into stomach with no leak but there was pooling of a small amount of barium in the submucosal space at the upper end of the mucosotomy site without passage down the tunnel into the mediastinum. X-ray showed intact endoscopic clips at the mucosotomy site. Patient was afebrile and only had the expected post-procedure mild chest discomfort. She was continued nil per oral for an additional day and Barium swallow study was repeated which did not show any further pooling of barium at the mucosotomy site and the barium had passed freely into the stomach without a leak. Pooling of a small amount of barium at the mucosotomy site was likely due to the passage of barium into the submucosal space between the clips as they might not have created watertight closure of mucosotomy. This finding is usually of no clinical consequence if barium does not leak out through the tunnel into the mediastinum. Starting myotomy at least 2–3 cm distal to mucosotomy site such that the submucosal space closes off by mucosal flap above the myotomy site and meticulous, watertight closure of mucosotomy site may prevent such occurrence.

Migration of dissolved matter at Serebryanka R. Mouth, the basin of the Sea of Japan (Sikhote Alin Reserve)

Ions of major salt composition and dissolved forms of some microelements (F, B, Sr, Rb, Cs, V, As, Mo, U) at the mouth of the Serebryanka R. (Sikhote Alin Reserve) are shown to feature conservative behavior in July 2009. The distribution of dissolved mineral phosphorus is shown to be controlled mostly by chemical processes (desorption from river suspension), even during vegetation period, while the role of biological consumption is secondary. The behavior of dissolved organic phosphorus and silicon is nearly conservative. A considerable amount of barium (up to 46% of its concentration in river water) is shown to be removed from solution, maybe because of its sorption on particulate matter of continental runoff. Ittrium and rare-earth elements (La, Ce, Pr, Nd, Dy, Ho) show an abrupt decrease in the concentrations of their dissolved forms at the initial stages of river water penetration into the sea. This decrease is supposedly due to coagulation and flocculation of organic and organic-mineral colloids.

Barium Peritonitis in Small Animals

ABSTRACTBarium peritonitis is extremely rare, but is difficult to treat and may be life-threatening. Barium suspension leakage from the gastrointestinal tract into the abdominal cavity has a time-dependent and synergistically deleterious effect in patients who have generalized bacterial peritonitis. The severity of barium peritonitis is dependent on the quantity of barium in the abdominal cavity. Barium sulfate leakage results in hypovolemia and hypoproteinemia by worsening the exudation of extracellular fluid and albumin. Abdominal fluid analysis is a useful and efficient method to diagnose barium peritonitis. Serial radiographs may not be a reliable or timely diagnostic technique. Initial aggressive fluid resuscitation and empirical broad-spectrum antibiotic treatment should be instituted promptly, followed quickly by celiotomy. During exploratory surgical intervention, copious irrigation and direct wiping with gauze are employed to remove as much barium as possible. Omentectomy should be considered when needed to expedite barium removal. Despite aggressive medical and surgical treatments, postoperative prognosis is guarded to poor due to complications, such as acute vascular shock, sepsis, diffuse peritonitis, hypoproteninemia, electrolyte imbalance, cardiac arrest, small bowel obstruction related to progression of granulomas and adhesions in the abdominal cavity. Therefore, intensive postoperative monitoring and prompt intervention are necessary to maximize chances for a positive outcome. For those that do survive, small bowel obstruction is a potential consequence due to progression of abdominal adhesions.

PP23 ARGON PLASMA COAGULATOR IN A 2-MONTH-OLD CHILD WITH TRACHEO-OESOPHAGEAL FISTULA

A 2 month-old boy was admitted to the authors’ hospital because of regurgitation and persistent cough during breastfeeding. A chest X-ray examination and a barium esophagogram disclosed small amounts of barium passing in the trachea, suggesting a tracheoesophageal fistula (TEF). Bronchoscopy combined with upper gastrointestinal (GI) endoscopy performed with the patient under general anesthesia confirmed the fistula. The TEF was treated by injection of 1 ml Glubran 2 from the esophageal side. A nasogastric tube was placed for feedings, and 7 days later, a barium esophagogram showed a reduction of caliber but not complete closure of the TEF. Unsuccessful fistula obliteration with Glubran was attributed to technical difficulties in catheterization of the fistula orifice, mainly resulting from its close proximity to the upper esophageal sphincter and to its small caliber. Therefore, an argon plasma coagulator (APC) probe with a circumferentially oriented nozzle was used from the esophageal side as an alternative technique to fulgurate the residual fistula orifice (see video). A nasogastric tube was placed for feedings. Oral feeding was started 7 days later when a barium esophagogram confirmed complete fistula closure. At the 2-year follow-up visit, the boy was asymptomatic, and the barium esophagogram was negative. This report describes a case in which esophagoscopy gave a clear view of the fistula due to its direction from esophagus to trachea. Complete fistula obliteration was not obtained with Glubran. However, APC was successfully used to close the residual fistula orifice. The authors suggest that APC can be used as an alternative endoscopic technique to repair TEF when other techniques fail.

Removal of Sludge Heels in Savannah River Site Waste Tanks with Oxalic Acid

The Savannah River Site (SRS) is preparing two tanks for closure. The first step in preparing the tank for closure is mechanical sludge removal. In mechanical sludge removal, a liquid such as inhibited water or salt solution is added to the tank, the liquid is mixed with the sludge to form a slurry, and the slurry is transported from the tank. Mechanical cleaning removes a large fraction of the sludge in the tank, but it leaves a sludge heel of several thousand gallons. SRS employs chemical cleaning to remove this sludge heel. In chemical cleaning, oxalic acid is added to the tank to dissolve the sludge, and the liquid, containing the dissolved sludge, is transported from the tank. The authors conducted demonstrations of the chemical cleaning process with simulated SRS waste and actual SRS waste to assess the effectiveness of oxalic acid in dissolving SRS sludge. Following these demonstrations, SRS conducted chemical cleaning in two waste tanks (referred to as Tank A and Tank B). During chemical cleaning, the authors analyzed samples to assess the effectiveness of the chemical cleaning in removing the sludge heel. The conclusions from this work follow. With the exception of iron, the dissolution of sludge components from Tank A agreed with results from the actual waste demonstration performed in 2007. The fraction of iron removed from Tank A by chemical cleaning was significantly less than the fraction removed in the SRNL demonstrations. The likely cause of this difference is the high pH following the first oxalic acid strike. The dissolution of sludge components from Tank B agreed with results from the actual waste demonstration performed in 2007. The fraction of plutonium removed from Tank B by chemical cleaning was slightly higher than the fraction removed in the SRNL demonstrations. Most of the sludge mass remaining in the tank is iron and nickel. The remaining sludge contains significant amounts of barium, chromium, and mercury. Most of the radioactivity remaining in the residual material is beta emitters and 90Sr. The chemical cleaning removed a large fraction of the uranium, aluminum, calcium, sodium, strontium, and cesium. The chemical cleaning was not effective at removing nickel, mercury, plutonium, americium, and curium.

Remnant stomach-jejunal dual pathways reconstruction after laparoscope-assisted radical proximal gastrectomy

Objective To investigate the value of remnant stomach-jejunal dual pathways reconstruction after laparoscope-assisted radical proximal gastrectomy in the treatment of upper gastric cancer. Methods Twenty-five patients with upper gastric cancer underwent laparoscope-assisted radical proximal gastrectomy and the remnant distal stomach was preserved for side-to-side remnant stomach-jejunal anastomosis and end-to-side jejuno-jejunal anastomosis to reconstruct dual pathways. Results The mean operation time was (240±35) minutes, the mean number of lymph nodes dissected were 22±5, and all the incised margins were negative. No anastomotic leakage, obstruction or stenosis occurred. All patients received postoperative barium meal examination. A large amount of barium directly entered the jejunum, leaving a small amount of barium entered the jejunnum via the route of remnant stomach-duodenum, and was detained in the remnant stomach for 30-60 minutes. No esophageal reflux of barium was observed. All the patients were followed up for 4-18 months, no reflux esophagitis was detected and the short-term life quality was satisfactory. Conclusions Remnant stomach-jejunal dual pathways reconstruction prevents the reflux esophagitis and dumping syndrome, preserves the pathway of duodenum and promotes the life quality of patients. Key words: Gastric cancer; Laparoscope; Reconstruction of digestive tract

A Young Man With a New Diagnosis of Achalasia

d Clinical Scenario A 32-year-old man began to experience food sticking ntermittently in the midchest about 2 years ago. By the time he resents to the gastroenterology clinic, he is complaining of ysphagia at every meal for most hard, solid foods (ie, bread, eats, uncooked vegetables), and for the past 4 months he has oted dysphagia for liquids, especially cold beverages. Once or wice a week, after his large evening meal, he experiences reguritation of recently eaten food with a nonacidic taste. His wife omplains he “gurgles” at night and sometimes awakes her with oughing. He denies chest pain, but does complain of “hearturn,” improving with over-the-counter Prilosec (Proctor & amble, Cincinnati, OH). His weight is down 10 lb. The complaints of dysphagia for both solids and liquids aise the suspicion of achalasia. A barium esophagram shows a ildly dilated esophagus with a column of barium maintained ust below the clavicles with no emptying in the upright posiion over a 5-minute period. The distal esophagus has narowed, with a small amount of barium intermittently streaming nto the stomach. No orderly peristalsis is seen on fluoroscopy. sophageal manometry confirms the diagnosis, finding a high ower esophageal sphincter (LES) pressure (56 mm Hg) with ncomplete relaxation and low-amplitude, simultaneous mirror mage waves after all swallows of water. The patient and his wife return to your office after completng his tests. They have read extensively about achalasia on the nternet. They have many questions: Will I ever be able to eat ormally? Can you cure this disease? What is the best treatent—pneumatic dilation, surgical myotomy, or botulinum oxin injections? What are the side effects and which one will ive me the most relief for a long time?

EFFECT OF ZEOLITE CRYSTALLITE SIZE ON Pt/KL CATALYSTS USED FOR THE AROMATIZATION OF n-OCTANE

The effects of varying zeolite crystallite size in n-octane aromatization over Pt/KL have been studied on a series of catalysts. Various KL zeolites were synthesized via microwave-hydrothermal treatment, which allows for good control of crystallite morphology. Zeolites with different crystallite sizes were prepared by varying aging time (17–24 h), amount of barium (0–445 ppm), and seeding (0–8 wt%). The results showed that higher aging time resulted in smaller zeolite crystallite size, whereas the addition of barium resulted in larger crystallite size. Moreover, the addition of seeding reduced the crystallite size from 1.47 to 0.94 μm. Pt supported on different zeolite catalysts (Pt/KL) was prepared by vapor phase impregnation (VPI). The fresh catalysts were characterized by DRIFTS of adsorbed CO and volumetric hydrogen chemisorption. The results indicated that Pt clusters are well dispersed inside the zeolite channel in all the catalysts prepared. The aromatization of n-octane was tested on the different catalysts at 500°C and atmospheric pressure. It was found that the catalytic activity of all catalysts dropped rapidly after about 200 min on stream due to coke plugging inside the pore of the KL zeolite. It was also observed that less ethylbenzene (EB) and o-xylene (OX) were obtained as the conversion increased because both EB and OX are converted to smaller molecules such as benzene, toluene, etc., by secondary hydrogenolysis. Furthermore, the EB/OX ratio increases with zeolite crystallite size due to an enhanced preferential conversion of the larger OX molecules compared to the narrower EB as their path through the pores is restricted.