Fischerella sp. biomass measurement by using graphite electrodes

2019 ◽  
Vol 28 (6) ◽  
pp. 33-38
Author(s):  
José Martín Márquez-Villa ◽  
Juan Carlos Martínez-Espinosa ◽  
Juan Carlos Rodríguez-Sierra
Keyword(s):  
High Reliability ◽  
Electric Circuit ◽  
Dry Weight ◽  
Electrical System ◽  
Graphite Electrodes ◽  
Living Biomass ◽  
Electrical Admittance ◽  
Physical Quantities

For several decades, the electrical admittance has been very useful for the determination of physical quantities, such as the characterization of some electrical properties of interest in organic samples. In this work, an electrical system based on graphite electrodes to determine the amount of living biomass of the cyanobacteria Fischerella sp. is proposed. Cyanobacteria are phototrophic microorganisms with applications on bioremediation, pharmaceutics, medicine, among others. The strain was characterized in BG-11 medium and cultured at different biomass concentrations. Samples were evaluated by electrical admittance and contrasted by the technique of dry weight in order to correlate the results registered by the/a proposal electric circuit. Scanning frequencies from admittance went in an order from 10 Hz to 1 000 000 Hz. Also, they showed a reproducibility, getting deviations of 6.45 × 10-5. This electrical system can be used to evaluate Fischerella sp. living biomass concentrations with high reliability.

scholarly journals THE FORMULATION OF DRY CURCUMA (CURCUMA XANTHORRHIZA ROXB.) EXTRACT MICROCAPSULES BY SPRAY WET MICROENCAPSULATION TECHNIQUES

2018 ◽  
Vol 11 (3) ◽  
pp. 226
Author(s):  
Samran Samran ◽  
Dalimunthe Dalimunthe ◽  
Dalimunthe Dalimunthe ◽  
Dalimunthe Dalimunthe
Keyword(s):  
Sodium Alginate ◽  
Brown Algae ◽  
Raw Materials ◽  
Light Exposure ◽  
Gastrointestinal Disease ◽  
Dry Weight ◽  
Compressibility Index ◽  
Curcuma Xanthorrhiza

 Objective: Curcuma xanthorrhiza Roxb. was used as hereditary medicinal plant for prevention of liver dysfunction, gastrointestinal disease, fever, and hemorrhoid. Curcuma extract was easy to damage because the light exposure, change of pH, weather and a long period of storage time. The problem can be solved by coating the extract with spray wet microencapsulation (SWM) technique. SWM technique is a method of preparing microcapsules in which a solution, suspension, or emulsion with a charged matrix is sprayed into opposing solution. The aim of this research was to formulate the dry Curcuma extract with SWM technique using sodium alginate as matrix.Methods: Brown algae (Sargassum ilicifolium) was a main resource of alginate acid. It was isolated using HCl 5% to make alginate acid and sodium alginate that was obtained by adding Na2CO3 5% to alginate acid solution. The microencapsulation process of Curcuma extract was done by SWM technique. The formula of Curcuma extract microencapsulation was design into three formulas: F1, F2, and F3. Microcapsules of Curcuma extract were being characterized for color intensity, analysis of scanning electron microscope (SEM), compressibility index, flowing time, and determination of angle repose.Results: The results showed that the higher concentration of sodium alginate used, the dry Curcuma extract microcapsules produced better. Particle size of extract microcapsules of Curcuma extract microcapsules SEM from F1, F2, F3 was 20 μm whereas dry weight of extracted microcapsule of Curcuma grows with increasing concentration of sodium alginate: F1 (0.2%) 19.86±0.11 g, F2 (0.4%) 20.66±0.73, F3 (0.6%) 21.29±0.64. The flowing time of F1, F2, and F3 was 6.92±0.56, 7.42±0.50, and 8.05±0.54 s consecutively.Conclusions: Based on the analysis of the study result, it can be concluded that the raw materials of Curcuma extract can be made by SWM technique using sodium alginate isolated from brown algae, and the characterization of dry Curcuma extract microcapsule of the three formulas met the requirements of the pre-formulation tests for capsule dosage form.

scholarly journals Characterization of Phytoavailable Copper in Compost-Peat Substrates and Determination of a Toxicity Level

2000 ◽  
Vol 125 (6) ◽  
pp. 765-770 ◽  
Author(s):  
Annette S. Bucher ◽  
Manfred K. Schenk
Keyword(s):  
Dry Weight ◽  
Yield Reduction ◽  
Good Prediction ◽  
Yard Waste ◽  
Iron Supply ◽  
Toxicity Level ◽  
Decreasing Ph ◽  
Substrate Ph

Heavy metal-sensitive `Express Orchid' petunias (Petunia ×hybrida Hort Vilm.-Andr. `Express Orchid') were grown in substrates of 2 green yard waste compost: 3 peat (v/v) with target Cu contents of 100 and 200 mg·kg-1 at varying pH. Iron supply was also varied. Copper contents of the substrate were determined by H2O, NH4NO3, NH4OAc, CaCl2, CaCl2-DTPA, and aqua regia extraction. Plant Cu concentration increased with increasing Cu supply and decreasing pH, indicating that Cu phytoavailability depended on substrate pH. Extraction of fresh substrates with CaCl2-DTPA provided a good prediction of plant Cu concentration and reflected well the influence of pH on Cu phytoavailability. The percentage of CaCl2-DTPA extractable Cu increased with decreasing pH. Extractions of Cu with NH4NO3, H2O, NH4OAc, and CaCl2 resulted in very low extractable amounts and hence were not suitable. Plants showed Cu toxicity induced iron-like deficiency chlorosis, which was alleviated by additional Fe supply. This Fe supply did not seem to affect total Fe concentration of petunias, but reduced Cu concentration of the shoots. Since yield reduction was not observed, the occurrence of chlorosis during the culture period was chosen as the toxicity parameter, resulting in a Cu threshold toxicity level of 12.3 mg.kg-1 plant dry weight. From this, a threshold toxicity level for CaCl2-DTPA extractable Cu in compost-peat substrates of 3 mg.L-1 substrate was determined. Chemical name used: diethylenetriamine-pentaacetic acid (DTPA).

Characterization of frozen hydrated biological specimens by low-loss EELS

1992 ◽  
Vol 50 (2) ◽  
pp. 1572-1573
Author(s):  
Songquan Sun ◽  
Richard D. Leapman
Keyword(s):  
Water Content ◽  
Direct Method ◽  
Internal Standard ◽  
Dry Weight ◽  
Dark Field ◽  
Protein Solutions ◽  
Subcellular Compartment ◽  
Differential Shrinkage ◽  
Electron Energy Loss

Analyses of ultrathin cryosections are generally performed after freeze-drying because the presence of water renders the specimens highly susceptible to radiation damage. The water content of a subcellular compartment is an important quantity that must be known, for example, to convert the dry weight concentrations of ions to the physiologically more relevant molar concentrations. Water content can be determined indirectly from dark-field mass measurements provided that there is no differential shrinkage between compartments and that there exists a suitable internal standard. The potential advantage of a more direct method for measuring water has led us to explore the use of electron energy loss spectroscopy (EELS) for characterizing biological specimens in their frozen hydrated state.We have obtained preliminary EELS measurements from pure amorphous ice and from cryosectioned frozen protein solutions. The specimens were cryotransfered into a VG-HB501 field-emission STEM equipped with a 666 Gatan parallel-detection spectrometer and analyzed at approximately −160 C.

Characterization of Impressed Current Technique to Model Corrosion of Reinforcement in Concrete

2020 ◽  
Vol 11 (1) ◽  
pp. 93-99
Author(s):  
Abu Zakir Morshed ◽  
Sheikh Shakib ◽  
Tanzim Jahin
Keyword(s):  
Immersion Time ◽  
Chloride Content ◽  
Engineering Science ◽  
Coastal Regions ◽  
Faraday’S Law ◽  
Current Technique ◽  
Corrosion Cell ◽  
Impressed Current

Corrosion of reinforcement is an important durability concern for the structures exposed to coastal regions. Since corrosion of reinforcement involves long periods of time, impressed current technique is usually used to accelerate the corrosion of reinforcement in laboratories. Characterization of impressed current technique was the main focus of this research,which involved determination of optimum chloride content and minimum immersion time of specimens for which the application of Faraday’s law could be efficient. To obtain optimum chloride content, the electrolytes in the corrosion cell were prepared similar to that of concrete pore solutions. Concrete prisms of 200 mm by 200 mm by 300 mm were used to determine the minimum immersion time for saturation. It was found that the optimum chloride content was 35 gm/L and the minimum immersion time for saturation was 140 hours. Accounting the results, a modified expression based on Faraday’s law was proposed to calculate weight loss due to corrosion. Journal of Engineering Science 11(1), 2020, 93-99

The Determination of Sense via Deleuze and Blanchot: Paradoxes of the Habitual, the Immemorial, and the Eternal Return

2008 ◽  
Vol 2 (2) ◽  
pp. 155-177 ◽  
Author(s):  
Eugene Brently Young
Keyword(s):  
Eternal Return

Eternal return is the paradox that accounts for the interplay between difference and repetition, a dynamic at the heart of Deleuze's philosophy, and Blanchot's approach to this paradox, even and especially through what it elides, further illuminates it. Deleuze draws on Blanchot's characterisations of difference, forgetting, and the unlivable to depict the ‘sense’ produced via eternal return, which, for Blanchot, is where repetition implicates or ‘carries’ pure difference. However, for Deleuze, difference and the unlivable are also developed by the living repetition or ‘contraction’ of habit, which results in his distinctive characterization of ‘force’, ‘levity’, and sense in eternal return.

BIOASSAY OF PROLACTIN

1969 ◽  
Vol 60 (1) ◽  
pp. 91-100 ◽  
Author(s):  
Charles S. Nicoll
Keyword(s):  
Epithelial Cells ◽  
Lipid Content ◽  
Dry Weight ◽  
Fat Content ◽  
Assay Sensitivity ◽  
Mucosal Epithelium ◽  
Wet Weight ◽  
Total Dry Weight

ABSTRACT The response of the pigeon crop-sac to systemically acting prolactin (injected subcutaneously) was evaluated by measuring the wet weight of the responsive lateral lobes of the organ and by determining the dry weight of a 4 cm diameter disc of mucosal epithelium taken from one hemicrop. Of several different injection schedules tested, administration of prolactin in four daily injections was found to yield optimal responses. When compared with a graded series of prolactin doses, measurement of the mucosal dry weight proved to be a better method of response quantification than determination of the crop-sac wet weight with respect to both assay sensitivity and precision. The submucosal tissue of the crop-sac was estimated to constitute about 64 % of the total dry weight of the unstimulated organ and it was found to be relatively unresponsive to prolactin stimulation in comparison with the mucosa. The lipid content of the mucosal epithelium was determined using unstimulated crop-sacs or tissues which showed varying degrees of prolactin-induced proliferation. The fat content of the mucosal epithelial cells increased only slightly more rapidly than the dry weight or the defatted dry weight of the mucosa. Suggestions are made for the further improvement of the systemic crop-sac assay for prolactin.

SEM/EDS Characterization of Uncommon Metal Whiskers and Determination of Underlying Growth Mechanisms

2018 ◽  
Author(s):  
D. Basak ◽  
L. H. Ponce
Keyword(s):  
Reliability Analysis ◽  
Case Studies ◽  
Whisker Growth ◽  
Innovation Systems ◽  
Growth Mechanisms ◽  
Crystal Oscillator ◽  
Analysis Laboratory ◽  
Investigative Techniques

Abstract Two case-studies on uncommon metals whiskers, performed at the Reliability Analysis Laboratory (RAL) of Northrop Grumman Innovation Systems, are presented. The components analyzed are an Oven Controlled Crystal Oscillator (OCXO) and an Electromechanical Relay. Investigative techniques were used to determine the chemical and physical makeup of the metal whiskers and develop an understanding of the underlying effects and mechanisms that caused the conditions conducive to whisker growth.

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