Split Column Research Articles

Lutein Production by Halophilic Microalgae Using Anaerobic Digestate as the Substrate and Its Potential Application as a Biopesticide.

Production of value-added products from waste anaerobic digestate is economically and environmentally important for sustainable development of industrial process and products. In this study halophilic microalgae, Chlorella vulgaris 92001, Chlorella vulgaris 50291, Chlorella vulgaris 10241 and Tetraselmis indica, were initially screened for lutein production using synthetic dairy digestate (DD), municipal digestate (MD) and poultry digestate (PD) as no-cost substrates. Screening and optimization of parameters, such as dilution, pH, MgCl2, NaCl, NaHCO3 and inoculum concentration for maximum lutein production were further performed employing statistically designed Plackett-Burman and response surface methodology. Cultivation of C. vulgaris 92001 in a split column photobioreactor under optimum culture condition showed increase in lutein production by 2.36-fold in batch mode. The influence of different hydraulic retention time (HRT) values of 150, 130, 100 and 90h on lutein production was evaluated in continuous mode with the split column photobioreactor. Lutein produced using the synthetic poultry digestate showed good potential biopesticide activity against Spodoptera litura (fall armyworm). Overall, this study demonstrated bioprocess development to produce lutein using synthetic anaerobic digestate from marine algae and its potential application as a biopesticide.

A Detailed Hydrodynamic Study of the Split-Plate Airlift Reactor by Using Non-Invasive Gamma-Ray Techniques

This study focused on detailed investigations of selected local hydrodynamics in split airlift reactor by using an unconventional measurements facility: computed tomography (CT) and radioactive particle tracking (RPT). The local distribution in a cross-sectional manner with its radial’s profiles for gas holdup, liquid velocity flow field, shear stresses, and turbulent kinetic energy were studied under various gas velocity 1, 2 and 3 cm/s with various six axial level z = 12, 20, 40, 60, 90 and 112 cm. The distribution in gas–liquid phases in the whole split reactor column, the riser and downcomer sides, including their behavior at the top and bottom sections of the split plate was also described. The outcomes of this study displayed an exemplary gas–liquid phases dispersion approximately in all reactor’s zones and had large magnitude over the ring of the sparger as well as upper the split plate. Furthermore, the outcomes pointed out that the distribution of this flow may significantly impacts the performance of the split reactor, which may have essential influence on its performance particularly for microorganisms culturing applications. These outcomes are dependable as benchmark information to validate computational fluid dynamics (CFD) simulations and other models.

Seismic response analysis of subway underground stations using split columns

Taking the underground station research project of the first phase of Nanning Rail Transit Line 4 as the engineering background, based on the ABAQUS large-scale finite element software, the numerical integration method, the constitutive relationship of structural materials and the determination of boundary conditions appear in the model establishment. The key problems of seismic wave selection and input are analyzed. The appropriate 3D standard section metro station structure calculation model is established. The seismic wave baseline drift phenomenon occurs in the dynamic time history analysis of ABAQUS. The Seismic Signal software is used to correct the seismic wave baseline. On the basis of theoretical analysis, through the numerical simulation, the dynamic time-history analysis of the frame column and the split column in the metro station under the two-way coupled seismic action is carried out, and the elastoplasticity of the metro station adopting the frame column and the split column is carried out. Time-history analysis found that the bearing capacity of the split column under the large earthquake is about 16% lower than that of the frame column, but the ductility is increased by about 35%. In other words, the split column loses part of the bearing capacity and changes the force of the frame column. Features greatly improve the ductility of the column.

Cultivation of oleaginous yeast Rhodotorula mucilaginosa IIPL32 in split column airlift reactor and its influence on fuel properties

Lipid-derived from oleaginous yeast is now being considered as promising feedstock for production of biofuels and oleochemicals. One of the major advantages of such yeasts over plant or algae is high productivity and cultivation capability under controlled environment. Choice of suitable reactor system with minimum investment of energy and use of low cost renewable carbon source for lipid generation are keys to the commercial success of yeast lipid-based processes. A split column airlift reactor was characterized and used to study lipid production in oleaginous yeast Rhodotorula mucilaginosa IIPL32 (MTCC 25056). Lipid accumulation in the yeast was observed to be significantly influenced by physical variables namely aeration, sugar concentration and residence time. A non-polar lipid yield of 8.6% based on consumed sugar was achieved under the optimized condition of 1.5 vvm aeration, 20 g/L sugar concentration and 12 h of residence time. With sugarcane bagasse hydrolysate as the carbon source, under optimized condition palmitic (C16:0), palmitoleic (C16:1), oleic (C18:1) and linoleic acid (C18:2) were major fatty acid components. Predicted fuel properties of transesterified lipid satisfied all the criteria to be an excellent biodiesel as per ASTM D6751 and EN 14214.

Modified split column technique for the experimental determination of thermal conductivity of polymers

The continuous increase in the utilization of polymeric materials in many specific applications has demanded detailed knowledge of their physical properties, both during their processing as raw material, as well as in the overall range of the working temperature of the final polymer product. Nowadays, mathematical modeling has become an established tool for improving process control and product quality in polymer processing. As models become more sophisticated, there is an increasing need for reliable thermo-physical properties data. In this work, a very simple and low cost arrangement, a variation of the well-known split column method, is employed in the experimental determination of the thermal conductivity of some selected polymers. Rectangular parallelepiped shaped samples, (200 × 100 × 20) mm were prepared by cutting such pieces from long commercial plates or through an extrusion process starting from the powder or pellets of the solid polymer. Experimental results show a solid consistence when they are checked against results obtained by other techniques.

Airlift column photobioreactors for Porphyridium sp. culturing: Part I. effects of hydrodynamics and reactor geometry

Photosynthetic microorganisms have been attracting world attention for their great potential as renewable energy sources in recent years. Cost effective production in large scale, however, remains a major challenge to overcome. It is known to the field that turbulence could help improving the performance of photobioreactors due to the so-called flashing light effects. Better understanding of the multiphase fluid dynamics and the irradiance distribution inside the reactor that cause the flashing light effects, as well as quantifying their impacts on the reactor performance, thus, are crucial for successful design and scale-up of photobioreactors. In this study, a species of red marine microalgae, Porphyridium sp., was grown in three airlift column photobioreactors (i.e., draft tube column, bubble column, and split column). The physical properties of the culture medium, the local fluid dynamics and the photobioreactor performances were investigated and are reported in this part of the manuscript. Results indicate that the presence of microalgae considerably affected the local multiphase flow dynamics in the studied draft tube column. Results also show that the split column reactor works slightly better than the draft tube and the bubble columns due to the spiral flow pattern inside the reactor.

Interpreting temperature–strain data from mesoscale clathrate experiments

Gas hydrates may play an important role in global climate change, carbon sequestration, energy production and seafloor stability. However, formation and dissociation pathways in geologically complex systems are poorly defined. We present a new approach to processing large amounts of data from a LUNA distributed sensing system (DSS) in the seafloor process simulator (SPS) at Oak Ridge National Laboratory to monitor and visualize gas hydrate formation and dissociation in heterogeneous sediments. The DSS measures relative temperature/strain change with a high spatial resolution allowing the heat of reaction during gas hydrate formation/dissociation to be used to locate clathrate processes in space and time within the vessel. Optical fibers are placed in the sediment following an Archimedean spiral design and the position of each sensor is determined iteratively over the arc length using Newton's method. The DSS data are then gridded with a natural neighbor interpolation algorithm to allow contouring. The locations of sensors on the fiber were verified with hot and cold stimuli in known locations. Software was developed to produce temperature/strain linear and polar plots, which aid in locating significant hydrate formation/dissociation events. Results from an experiment using a vertically split column of sand and silt clearly showed initial hydrate formation in the sand, followed by slow encroachment into the silt. Similar systems and data processing techniques could be used for monitoring of hydrates in natural environments or in any situation where a hybrid temperature/strain index is useful.

Gas chromatography/isotope-ratio mass spectrometry method for high-precision position-dependent 15N and 18O measurements of atmospheric nitrous oxide.

We describe an automated gas chromatography/isotope-ratio mass spectrometry (GC/IRMS) method for the determination of the (18)O and position-resolved (15)N content of nitrous oxide at natural isotope abundance. The position information is obtained from successive measurement of the isotopic composition of the N(2)O(+) ion at m/z 44, 45, 46 and the NO(+) fragment ion at m/z 30, 31. The fragment ion analysis is complicated by a non-linearity in the mass spectrometer that has to be taken into account. Evaluation of the absolute peak areas allows for a simultaneous determination of the N(2)O mixing ratio for atmospheric samples. Samples with mixing ratios ranging from a few nmol/mol up to the percent level can be analyzed using different sample inlet systems. The high concentration inlet system provides an easy and quick method to carry out various diagnostic tests, in particular to perform realistic linearity tests. A gas chromatographic set-up with a split column and a backflush possibility improves analytical precision and excludes interferences by substances with long retention times from preceding runs. We also describe a new open split interface that uses only a single transfer capillary to the mass spectrometer for sample and reference gas.

5346622 Hydrocarbon class separation and quantitation by split column effluent analysis

Methods of separating and classifying the relative amounts of two or more classes of hydrocarbon molecules in a sample are disclosed wherein an input stream comprising a mobile phase and the sample is injected into a chromatographic column, and an effluent stream exiting a chromatographic column is split into a first effluent stream and a second effluent stream. The mass of carbon in each of the classes of hydrocarbons in the first effluent stream is determined, preferably using a flame ionization detector, and the second effluent stream is directed through a variable restrictor, allowing the pressure and mass flow rate of the input stream to be independently controlled and improved results obtained. In a preferred embodiment the present invention also includes identifying the hydrocarbon molecules in the second effluent stream in order to verify the analysis or provide additional data, preferably by using an ultraviolet detector. The present invention is most preferably used to analyze the aromatic hydrocarbons in a sample of diesel fuel.

Determination of hippuric acid and o-, m- and p-methylhippuric acids in urine by capillary gas chromatography

A capillary gas chromatographic (GC) method for the simultaneous determination of urinary hippuric acid (HA) and o-, m- and p-methylhippuric acids (MHAs), metabolites of toluene and o-, m- and p-xylenes, respectively, is described. These metabolites are converted into their isopropyl derivatives by extractive alkylation with tetrahexylammonium ion as extracting agent and isopropyl bromide as alkylating reagent in benzene. The derivatives are analysed using a chromatograph equipped with hydrogen flame ionization detector, split injection system and DB-17 capillary column. Benzoylleucine is used as an internal standard. The derivatives are well separated within 5 min and no interfering peaks are observed. The calibration curves of HA and MHAs in the range 1-50 micrograms are linear and sufficiently reproducible for quantitative analysis. Urine can be analysed accurately and precisely by this method without prior clean-up of the sample.

Tunnel ulcer with double pyloric canal.

Double pyloric canal produces a recognizable roentgen pattern. A split barium column at the pyloric canal results in an interposed pseudo-defect which must not be confused with tumor mass. The condition is usually caused by a tunnel ulcer extending from the distal stomach to the duodenal bulb and is probably more common than the small number of reported cases would suggest.

A New List of Victors in the Caesarea at Isthmia

E XCAVATIONS in a Roman bath of Ancient Corinth have produced still another stele listing the victors in the games at Isthmia.' It was found on May 29, 1968, re-uesd in a sixth century latrine built above the rutined western colonnade of the brick courtyard of the bath (P1. 18, a). A water channel cut into its face A apparently joined a similar one cut into the flat surface of a split column drutm found near by. Other sections of similar water channel were found built into later Byzantine walls. The stele of small grained white marble originally had three faces, each one inscribed. Slender fillets ran along the angles between the faces. One dowel hole, centered on the bottom surface of the stele, held it to its base. Another dowel hole, centered on the top surface, held in place the capping ornament. Each face tapered slightly bottom to top. When the stele was re-used a trough 0.095 m. wide was cut the length of face A to serve as the water channel (P1. 17). The angle formed where face B met face C was cut away to permit face A to lie horizontally. Presently of face B only the left half is preserved and of face C the right half (Pl. 17). Height, 1.90 m.; width (face A) 0.43-0.44 m., (face B) 0.20 m., (face C) 0.19 m.; thickness (measured perpendicular to face A) 0.17 m. Height of letters, (face A) line 1, 0.03 m., lines 2-5, 0.023-0.027 m., lines 6-13, 0.02-0.025 m., lines 14-45, 0.017-0.02 m., (faces B and C) 0.018-0.02 m.

Rapid analysis of chlorinated hydantoin by gas chromatography

Gas chromatographic seperation of a number of chlorinated hydantoins has been carried out using a split column. A quantitative method for the determination of 3-trichloromethylthio-5-(1-ethylamyl)hydantoin (chlordantoin) in suppositories has been developed. The accuracy of the method and results of the assay are reported. Gas chromatographic seperation of a number of chlorinated hydantoins has been carried out using a split column. A quantitative method for the determination of 3-trichloromethylthio-5-(1-ethylamyl)hydantoin (chlordantoin) in suppositories has been developed. The accuracy of the method and results of the assay are reported.