Granule Diameter Research Articles

Biodegradation of p-cresol by aerobic granules in sequencing batch reactor

The cultivation of aerobic granules in sequencing batch reactor for the biodegradation of p-cresol was studied. The reactor was started with 100 mg/L of p-cresol. Aerobic granules first appeared within one month of start up. The granules were large and strong and had a compact structure. The diameter of stable granules was in the range of 1–5 mm. The integrity coefficient and granules density was found to be 96% and 1046 kg/m3, respectively. The settling velocity of granules was found to be in the range of 2×10−2–6×10−2 m/sec. The aerobic granules were able to degrade p-cresol upto 800 mg/L at a removal efficiency of 88%. Specific p-cresol degradation rate in aerobic granules followed Haldane model for substrate inhibition. High specific p-cresol degradation rate up to 0.96 g p-cresol/(g VSS·day) were sustained upto p-cresol concentration of 400 mg/L. Higher removal efficiency, good settling characteristics of aerobic granules, makes sequencing batch reactor suitable for enhancing the microorganism potential for biodegradation of inhibitory compounds.

Rheological behaviour of heated potato starch dispersions

Abstract The study was designed to investigate the rheological properties of heated potato starch dispersions. Water suspensions of starch were heated at 65, 80 or 95°C for 5, 15, 30 or 60 min. The dispersions obtained were examined for granule size distribution and rheology. It was found that the starch dispersions significantly differed in both respects. The mean diameters of starch granules were largest for the dispersion heated at 65°C and smallest for that heated at 95°C. As the heating temperature was raised, the yield stresses and consistency coefficients decreased, while the flow behaviour indexes and Casson plastic viscosities increased. There were also differences in the viscoelastic properties of the dispersions: for those heated at 65°C the storage and loss moduli increased with heating time whereas for those heated at 80°C both moduli decreased.

DBA-Lectin Reactivity Defines Mouse Uterine Natural Killer Cell Subsets with Biased Gene Expression1

Endometrial decidualization, a process essential for blastocyst implantation in species with hemochorial placentation, is accompanied by an enormous but transient influx of natural killer (NK) cells. Mouse uterine NK (uNK) cell subsets have been defined by diameter and cytoplasmic granule number, reflecting stage of maturity, and by histochemical reactivity with Periodic Acid Schiff (PAS) reagent with or without co-reactivity with Dolichos biflorus agglutinin (DBA) lectin. We asked whether DBA- and DBA+ mouse uNK cells were equivalent using quantitative RT-PCR analyses of flow-separated, midpregnancy (Gestation Day [gd] 10) cells and immunohistochemistry. CD3E (CD3)-IL2RB (CD122)+DBA cells were identified as the dominant Ifng transcript source. Skewed IFNG production by uNK cell subsets was confirmed by analysis of uNK cells from eYFP-tagged IFNG-reporter mice. In contrast, CD3E-IL2RB+DBA+ uNK cells expressed genes compatible with significantly greater potential for IL22 synthesis, angiogenesis, and participation in regulation mediated by the renin-angiotensin system (RAS). CD3E-IL2RB+DBA+ cells were further divided into VEGFA+ and VEGFA- subsets. CD3E-IL2RB+DBA+ uNK cells but not CD3E-IL2RB+DBA- uNK cells arose from circulating, bone marrow-derived progenitor cells by gd6. These findings indicate the heterogeneous nature of mouse uNK cells and suggest that studies using only DBA+ uNK cells will give biased data that does not fully represent the uNK cell population.

Cardiac Natriuretic Peptides and Development of Hereditary Hypertension in Rats

Ultrastructure of the right atrial cardiomyocytes of suckling ISIAH rats was studied to clarify the role of cardiac natriuretic peptides in hypertension development during the period when blood pressure is not yet elevated. Cardiomyocytes diameter was significantly greater, Golgi complex was more developed, and granules in the sarcoplasm were more abundant in ISIAH rats as soon as on postnatal day 12 in comparison with age-matched normotensive animals. The smaller diameter of granules and their qualitative composition (ratio of forming, mature, and dissolving forms) attest to active synthesis and release of secretory product. In 21-day-old ISIAH rats, granule size and qualitative composition reflected increased accumulation of hormones in the cells. Thus, morphological features of increased production of natriuretic peptides in the right atrial myocytes were revealed in rats during the first postnatal month before manifestation of hereditary hypertension.

Biodegradation of m-cresol by aerobic granules in a sequencing batch reactor

The present study was aimed at the development of aerobic granules in a sequencing batch reactor for the biodegradation of m-cresol. The reactor was started with 100 mg L−1 of m-cresol. Aerobic granules first appeared within 1 month of the start-up of the reactor. The granules were large and strong and had a compact structure. The diameter of stable granules on day 200 was in the range of 1.5–5 mm. The integrity coefficient and density of the granules was found to be 98% and 1046 kg m−3, respectively. The settling velocity of the granules was found to be in the range of 2–6×10−2 m s−1. The aerobic granules were able to degrade m-cresol up to 800 mg L−1 at a removal efficiency of 87%. UV and GC/MS studies confirmed that the biodegradation of m-cresol occurred via catechol via the ortho-cleavage pathway. The specific m-cresol degradation rate in aerobic granules followed the Haldane model for substrate inhibition. A high specific m-cresol degradation rate of up to 0.718 g m-cresol g−1VSS−1d−1 was sustained up to an m-cresol concentration of 400 mg L−1. The higher removal efficiency and good settling characteristics of aerobic granules make the sequencing batch reactor method suitable for enhancing the microorganism potential for biodegradation of inhibitory compounds.

The structure, density and settlability of anammox granular sludge in high-rate reactors

Microscopic observation and settling test were carried out to investigate the structure, density and settlability of anammox granules taken from a high-rate upflow anaerobic sludge blanket (UASB) reactor. The results showed that the anammox granules were irregular in shape and uneven on surface, and their structure included granule, subunit, microbial cell cluster and single cell. The gas pockets were often observed in the anammox granules, and they originated from the obstruction of gas tunnel by extracellular polymer substances (EPSs) and the inflation of produced dinitrogen gas. The volume of gas pockets became larger with the increasing diameter of anammox granules, which led to the decreasing density and the floatation of anammox granules. The diameter of anammox granules should be controlled at less than 2.20mm to avoid the granule floatation. A hypothesized mechanism for the granulation and floatation of anammox biomass was proposed.

Function suggests nano-structure: electrophysiology supports that granule membranes play dice

Cellular communication depends on membrane fusion mechanisms. SNARE proteins play a fundamental role in all intracellular fusion reactions associated with the life cycle of secretory vesicles, such as vesicle-vesicle and vesicle plasma membrane fusion at the porosome base in the cell plasma membrane. We present growth and elimination (G&E), a birth and death model for the investigation of granule growth, its evoked and spontaneous secretion and their information content. Using a statistical mechanics approach in which SNARE components are viewed as interacting particles, the G&E model provides a simple 'nano-machine' of SNARE self-aggregation behind granule growth and secretion. Results from experimental work, mathematical calculations and statistical modelling suggest that for vesicle growth a minimal aggregation of three SNAREs is required, while for the evoked secretion one SNARE is enough. Furthermore, the required number of SNARE aggregates (which varies between cell types and is nearly proportional to the square root of the mean granule diameter) affects and is statistically identifiable from the size distributions of spontaneous and evoked secreted granules. The new statistical mechanics approach to granule fusion is bound to have a significant changing effect on the investigation of the pathophysiology of secretory mechanisms and methodologies for the investigation of secretion.

Green banana (Musa cavendishii) flour obtained in spouted bed – Effect of drying on physico-chemical, functional and morphological characteristics of the starch

This study aimed to characterize green banana flour obtained by drying in a spouted bed, and to evaluate the functional properties (viscosity, swelling power and solubility), as well as the physical, morphological and hygroscopic behaviour (sorption isotherm). The results show that the rheological behaviour of flour with peel showed the highest values of viscosities but both flour showed high tendency to retrogradation. The swelling power and solubility were also similar for all flour samples, with low solubility under cold and high solubility under hot conditions. The starch granules diameter ranged from 70 to 110μm, with flattened and elongated morphology. The sorption isotherms were of type II (unpeeled banana flour) and III (peeled banana flour), and the BET model provided the best fit to the data, obtaining values for the monolayer adsorption of 5.78 and 4.34, respectively, and desorption of 4.85 and 4.14, respectively.

Temperature and salt effects on settling velocity in granular sludge technology

Settling velocity is a crucial parameter in granular sludge technology. In this study the effects of temperature and salt concentrations on settling velocities of granular sludge particles were evaluated. A two-fold slower settling velocity for the same granules where observed when the temperature of water decreases from 40 °C to 5 °C. Settling velocities also decreased with increasing salt concentrations. Experiments showed that when granules were not pre-incubated in a solution with increased salt concentration, they initially floated. The time dependent increase in mass and hence in settling speed of a granule due to salt diffusion into the granule was dependent on the granule diameter. The time needed for full salt equilibrium with the bulk liquid took 1 min for small particles from the top of the sludge bed and up to 30 min for big granules from the bottom of the sludge bed. These results suggest that temperature and salt concentration are important parameters to consider in the design, start-up and operation of granular sludge reactors and monitoring of these parameters will aid in a better control of the sludge management in anaerobic and aerobic granular sludge technology. The observations also give an explanation for previous reports which were suggesting that a start-up of granular sludge reactors is more difficult at low temperatures.

Study on properties of Cyperus esculentus starch grown in Xinjiang, China

AbstractThe chemical composition, morphological characteristics, and pasting properties of Cyperus esculentus starch (CES) grown in Xinjiang, China, were investigated and compared with those of potato starch (PS). The amylopectin (AP) content in CES was measured as of 83.82%. Most of the starch granules of Cyperus esculentus (CE) were round or elliptical while the granule diameter ranged from 3.41 to 12.12 µm with an average value of 8.60 µm, and had a typical polarization cross. The X‐ray diffraction (XRD) data showed that CES was of A‐type crystals. The peak viscosity value of CES paste was much lower than that of PS, and the freeze–thaw stability of CES paste was slightly higher than that of PS, but its light transmittance was lower.

Effect of COD/N ratio on cultivation of aerobic granular sludge in a pilot-scale sequencing batch reactor

Aerobic granular sludge was successfully cultivated with the effluent of internal circulation reactor in a pilot-scale sequencing batch reactor (SBR). Soy protein wastewater was used as an external carbon source for altering the influent chemical oxygen demand/nitrogen (COD/N) ratios of SBR. Initially, the phenomenon of partial nitrification was observed and depressed by increasing the influent COD/N ratios from 3.32 to 7.24 mg/mg. After 90 days of aerobic granulation, the mixed liquor suspended solids concentration of the reactor increased from 2.80 to 7.02 g/L, while the sludge volumetric index decreased from 105.51 to 42.99 mL/g. The diameters of mature aerobic granules vary in the range of 1.2 to 2.0 mm. The reactor showed excellent removal performances for COD and N₄⁺--N after aerobic granulation, and average removal efficiencies were over 93% and 98%, respectively. The result of this study could provide further information on the development of aerobic granule-based system for full-scale applications.

Experimental investigation of microsuspension filtration in a highly-permeable porous medium

Filtration of a microsuspension of aluminosilicate particles in a highly-permeable porous medium formed by a glass-sphere filling is investigated. The particle-to-filling granule diameter ratio varied from 0.046 to 0.109 and the volumic particle concentration ratio from 0.001 to 0.02. The data on the specimen permeability dynamics and its dependence on the initial concentration of the suspension microparticles and the ratio of their diameter to that of the porous medium granules are obtained. The permeability is shown to considerably vary along the specimen. Two stages of the porous medium damage by the trapped microparticles are established. The critical parameter of the formation of an impermeable cake in the initial region of the specimen are determined.

Effect of some Key Factors on the Strength of Recycled Concrete

Because there exists a used cement mortar layer outside the recycled aggregate, there are more interfaces inside recycled concrete, which would result in recycled concrete has different properties from ordinary concrete. In this paper, the effect of such key factors for recycled concrete mix ratio as water-cement ratio, cement strength, sand rate, maximum granule diameter and gradation on the properties of concrete with recycled coarse aggregate was studied by experiment, and the some useful suggestion for mix ratio of recycled concrete was provided.

Increase of susceptibility to the initiation of ammonium nitrate TNT containing mixtures

Obtained by coarsely dispersed granulites with a diameter of granules of 0.5-1.0, with percentages of ammonium nitrate, 80%, TNT 20%. 79 % 21%. Reliably detonate of detonator capsule CD-8A.

Second-law analysis of molten-salt thermal energy storage in thermoclines

The cyclic operation of a molten-salt thermocline tank is simulated to investigate the influence of internal granule diameter and external convection losses on tank performance. Practical constraints limiting thermocline tank height are taken into account. The authors two-temperature model, developed in earlier work (Solar Energy, 84, 974–985, 2010) for the analysis of heat transfer and fluid flow in the thermocline tank, is extended to monitor entropy generation and exergy transport. Storage performance is measured in terms of first- and second-law efficiency definitions, as well as a first-law efficiency used in conjunction with an outflow temperature criterion. Reducing the diameter of the fillerbed granules improves the thermocline tank performance by sustaining higher molten-salt outflow temperatures throughout the discharge phase of the cycle, which results in greater operational efficiency. External convection losses strongly influence entropy generation inside the tank fillerbed due to the development of radial temperature gradients and increased irreversible thermal diffusion. Convection losses also result in lower tank efficiencies due to the reduction of hot molten salt available inside the tank. A comparison of the different efficiency definitions employed in this work reveal that the ad hoc outflow temperature criterion used in past studies provides an overly conservative assessment of thermocline performance.

Development of aerobic granules in sequencing batch reactor with p-nitrophenol as sole carbon source

The present study was aimed at the development of aerobic granules in sequencing batch reactor (SBR) for the biodegradation of p-nitrophenol (PNP). The reactor was started with 50 mg L−1 of PNP. Aerobic granules first appeared within 1 month of the start up of the reactor. The granules were large and strong and had a compact structure. The diameter of stable granules on day 200 was in the range of 2–3 mm. The integrity coefficient and granule density was found to be 98% and 1,031 kg m−3 respectively. The settling velocity of granules was found to be in the range of 3 × 10−2 to 4 × 10−2m s−1. The aerobic granules were able to degrade PNP up to 700 mg L−1 at a removal efficiency of 87%. Gas chromatography–mass spectrometry studies confirmed that the biodegradation of PNP occurred by an initial oxygenase attack that resulted in the release of nitrite and the accumulation of hydroquinone. The specific PNP degradation rate in aerobic granules followed the Haldane model for substrate inhibition. A high specific PNP degradation rate up to 0.872 g PNP g−1 VSS−1 d−1 was sustained up to PNP concentration of 200 mg L−1. Higher removal efficiency, good settling characteristics of aerobic granules, makes a SBR suitable for enhancing the microorganism potential for biodegradation of inhibitory compounds.

Granulation of Fe–Al–Ce trimetal hydroxide as a fluoride adsorbent using the extrusion method

Iron–aluminum–cerium hydroxide (Fe–Al–Ce), which has high fluoride (F) adsorption capacity, was granulated via extrusion with cross-linked poly (vinyl alcohol) (PVA) as the binder. The optimum granulation conditions for acquiring an adsorbent with a high F adsorption capacity and compression strength were: binder/Fe–Al–Ce powder ratio, 1.4; average cylinder diameter of granules, 1.6mm; and drying temperature, 65°C. The granulated Fe–Al–Ce (GFAC) exhibited a Langmuir maximum adsorption capacity of 51.3mgg−1 at pH 7.0±0.2. The GFAC in columns exhibited an accumulated F adsorption capacity of 5.7mgg−1 and 3.2mgg−1 at the breakthrough point (1.0mgFl−1) for treatment of F-spiked tap water (pH 7.8±0.2) and F-bearing groundwater (pH 8.2±0.2), respectively, which is several times higher than most reported F adsorbents under the same conditions. Energy dispersive X-ray micro analysis (EDX) showed that F was distributed evenly in the cross-section of the used GAFC, suggesting that most active sites inside the GFAC were available for F removal. A regeneration method using NaAlO2 solution to desorb F from the used GFAC was developed, permitting the GFAC to keep over 60% of its F adsorption capacity even after four adsorption–regeneration cycles. The results demonstrated that GFAC was superior in F adsorption performance to conventional adsorbents such as activated alumina.

Novel standards in the measurement of rat insulin granules combining electron microscopy, high-content image analysis and in silico modelling.

Aims/hypothesisKnowledge of number, size and content of insulin secretory granules is pivotal for understanding the physiology of pancreatic beta cells. Here we re-evaluated key structural features of rat beta cells, including insulin granule size, number and distribution as well as cell size.MethodsElectron micrographs of rat beta cells fixed either chemically or by high-pressure freezing were compared using a high-content analysis approach. These data were used to develop three-dimensional in silico beta cell models, the slicing of which would reproduce the experimental datasets.ResultsAs previously reported, chemically fixed insulin secretory granules appeared as hollow spheres with a mean diameter of ∼350 nm. Remarkably, most granules fixed by high-pressure freezing lacked the characteristic halo between the dense core and the limiting membrane and were smaller than their chemically fixed counterparts. Based on our analyses, we conclude that the mean diameter of rat insulin secretory granules is 243 nm, corresponding to a surface area of 0.19 μm2. Rat beta cells have a mean volume of 763 μm3 and contain 5,000–6,000 granules.Conclusions/interpretationA major reason for the lower mean granule number/rat beta cell relative to previous accounts is a reduced estimation of the mean beta cell volume. These findings imply that each granule contains about twofold more insulin, while its exocytosis increases membrane capacitance about twofold less than assumed previously. Our integrated approach defines new standards for quantitative image analysis of beta cells and could be applied to other cellular systems.Electronic supplementary materialThe online version of this article (doi:10.1007/s00125-011-2438-4) contains peer-reviewed but unedited supplementary material, which is available to authorised users.

Application of Anion Multifunctional Additive in Polymer

The title introduced Anion anionic additive, character and application. Anionic additive can apply in paint, textile, coating, foam, plastic, etc. The structure of opal shale and the mechanism of release anion were discussed. The opal shale was comminuted by the airflow method. The average diameter of the opal shale granule was observed by granularity instrument. The result indicated that size is about 0.40-5.0μm. The printing poplin with high performance was achieved by intermingle technology and the generally printing means. The anion number (4000 ions /cm3) in printing poplin was measured.

Physicochemical properties of new starches isolated from Dioscorea opposita Thunb. bulbils

AbstractMorphological, crystal, and physicochemical properties, such as AM content, swelling power, solubility, and pasting properties of starches isolated from three different Shanyaodou (the bulbils of Dioscorea opposita Thunb., named Huaishanyao, Xichangmaoshanyao, and Maoshanyao, respectively) were investigated. The yield of starches was in the range 12.5–20.8% (dry starch/fresh whole bulbils). The AM content of Shanyaodou starches ranged from 33.3 to 36.7%. The shape of the three bulbils starch granules varied from round to oval or elliptic. The mean particle diameter of starch granules varied from 20.17 to 26.34 µm. Shanyaodou starches exhibited a C‐type XRD pattern and the degree of crystallinity was in the range 31.0–34.9%. The pasting peak viscosity, trough viscosity, and final viscosity of Shanyaodou starches ranged from 291.1 to 414.7, 210.8 to 227.0, and 350.0 to 359.2 rapid visco units (RVU), respectively, and the pasting temperature was in the range 83.6–87.3°C. The results showed that some of the Shanyaodou starches could be used in foods production as a thickening agent. The simple method of extraction and the high yield of starch from Shanyaodou might be attractive for production of Shanyaodou starch.