Effect of the Surface Characteristics of Seed on Copper Precipitation

1992 ◽  
Vol 26 (9-11) ◽  
pp. 2141-2143 ◽  
Author(s):  
Y. Wang ◽  
P. R. Anderson

Two types of seed with different surface area are used in a precipitation system to evaluate the effectiveness of seed surface characteristics on sludge dewatering properties. We expect that the surface area of the seed will stongly affect the sludge properties. The preliminary study shows that the seeded system has a lower precipitation pH and lower supersaturation level.

2013 ◽  
Vol 785-786 ◽  
pp. 749-752
Author(s):  
Ya Jun Luo ◽  
Qian Yan ◽  
Yong Chao Zhou ◽  
Deng Liang He ◽  
Xiao Li Hu

Activated carbon was modified with silica aerogel by the Sol-Gel. The surface characteristics and structure of activated carbon modified by the silica aerogel were characterized with N2 adsorption method, Scanning Electron Microscope and Thermal Analysis. The experiment results show that the silica aerogel can be used to modify activated carbon for the preparation of composite. SiO2 aerogel can effectively cover holes in the activated carbon, specific surface area of activated carbon composite modified by SiO2 aerogel was between activated carbon and silica aerogel. When MSiO2: MC is 1:3, specific surface area of the composite was 758.638 m2/g; When MSiO2:MC is 1:2, specific surface area of the composite was 760.38 m2/g; When MSiO2:MC is 1:1, specific surface area of the composite was 862.755 m2/g.


1994 ◽  
Vol 72 (3) ◽  
pp. 402-406 ◽  
Author(s):  
Jianhua Zhang

Cakile edentula produces dimorphic seeds from the upper and lower fruit segments. The upper seeds are well adapted to long-distance dispersal and have greater mean seed mass and surface area than those from the lower seeds. Great mean mass of the upper seeds is probably adaptive because it ensured early independent growth of seedlings and thus enhanced their chances of surviving environmental stresses. Large seed reserves also resulted in high chlorophyll content of the cotyledons. Large seed surface area resulted in large cotyledon area and cotyledon area to biomass ratio of the subsequent seedlings, but the adaptive advantage is not clear. Since increased seed surface area necessitates great protective tissues (fruit coat) that may improve the buoyant ability of seeds, large seed surface area of the upper seeds may be a result of selection for dispersal. Key words: seed mass, seed dimorphism, establishment, sand dune, selection, Cakile edentula.


2007 ◽  
Vol 544-545 ◽  
pp. 131-134
Author(s):  
Sardor Abdukakharovich Mavlyankariev ◽  
Dong Seok Rhee

Modified polypropylene granules (MDPG) were coated by manganese dioxide and their surface and adsorptive characteristics were studied. Surface characteristics of the adsorbent were investigated by B.E.T. surface area and mercury porosimetry. Coating has significantly increased the surface area of granules from 0.12 m 2 /g B.E.T. N 2 to 15.42 m 2 /g. Gas pycnometry measurements resulted in low density of 0.13 g/cm 3 for uncoated granules, the fact ascribed to 0.65 porosity measured. Coating increased micro pore volume of raw granules by a factor of 58. Adsorption experiments were conducted in column flow-through reactors at pH 6.0 and 10 g/L sorbent dosage for mixture of four metal species, each having 5 mg/L initial concentration. More than 60 % of Pb and Cu was removed within first 20 min, whereas just over 29 and 13 % for Cd and Zn respectively. Furthermore, more than 99, 84, 40, 16 % of Pb, Cu, Cd, and Zn was removed within 1 h. Adsorption efficiencies for 5 ppm of initial metal concentration at pH 5.0 and 10 g/L sorbent/solute ratio resulted in 4.9, 3.9 mg of Pb and Cu sorbed per gram of sorbent. And these ratios for separate metal ions were substantially higher than those for the mixture of the four metal ions. For 5 g/L of sorbent under the same parameters, removal efficiencies of Cd and Zn were respectively 0.98, 0.75 mg/g, correlating well with Freundlich adsorption model. Adsorption kinetics showed relatively fast removal rates within first 5 h of sorption. Desorption resulted in eluting 57, 70, 76, 78 % of the initial feeding concentrations for Pb, Cu, Cd, Zn, respectively.


2013 ◽  
Author(s):  
George J. Nelson

Analytical models developed to investigate charge transfer in Li-ion battery cathodes reveal distinct transport regimes where performance may be limited by either microstructural surface characteristics or solid phase geometry. For several cathode materials, particularly those employing conductive additives, surface characteristics are expected to drive these performance limitations. For such electrodes gains in performance may be achieved by modifying surface geometry to increase surface area. However, added surface area may present a diminishing return if complex structures restrict access to electrochemically active interfaces. A series of parametric studies has been performed to better ascertain the merits of complex, tailored surfaces in Li-ion battery cathodes. The interaction between lithium transport and surface geometry is explored using a finite element model in which complex surfaces are simulated with fractal structures. Analysis of transport in these controlled structures permits assessment of scaling behavior related to surface complexity and provides insight into trade-offs in tailoring particle surface geometry.


1998 ◽  
Vol 37 (4-5) ◽  
pp. 317-324 ◽  
Author(s):  
Sudhir N. Murthy ◽  
John T. Novak

Potassium ions appear to play an important role in determining the nature of activated sludge flocs. Relative to sodium, the concentration of potassium ions in most industrial activated sludge is typically low. Laboratory and field studies were conducted to examine the influence of potassium on activated sludge properties. The concentration of potassium affected the concentration of readily extractable (slime) proteins in the floc and the proteins in the surrounding solution. In laboratory tests, an increase in this cation's concentration beyond nutrient requirements impeded sludge dewatering properties as measured by capillary suction time (CST) and specific resistance to filtration (SRF) and associated with an increase in soluble protein. An increase in effluent total organic carbon and effluent turbidity was observed at higher concentrations of this ion. Conversely, an increase in concentration of potassium ion improved the settling properties of sludge with low equivalent monovalent to divalent cation ratio.


1968 ◽  
Vol 11 (4) ◽  
pp. 805-810 ◽  
Author(s):  
E. R. Nilo

Twelve young adult men with normal hearing and no history of ear disease took part in our study of the relation of vibrator surface area and static application force to the vibrator-to-head coupling. For vibrator surface areas of 1.125, 2.25, and 4.5 cm 2 coupled to the forehead under static forces of 150, 300, and 600 gm, monaural thresholds of bone-conduction hearing were determined at frequencies 250, 500, 1000, and 2000 Hz. With surface area constant, threshold improvement was frequency dependent. It decreased with increasing frequency until at 2000 Hz it was minimal. In contrast to this, with force constant, the influence of surface area was observed to begin at 2000 Hz. Preliminary study suggests this influence would extend to 4000 Hz. In view of the respective influence of application force and surface area to bone-conduction hearing, equating vibrator-to-head coupling on the basis of pressure (force per unit area), when there are two or more vibrators, may not represent an adequate control.


Author(s):  
S. Manocha ◽  
Parth Joshi ◽  
Amit Brahmbhatt ◽  
Amiya Banerjee ◽  
Snehasis Sahoo ◽  
...  

In the present work, a one step carbon activation process was developed by stabilized poly-blend. It is carbonized in nitrogen atmosphere and activated in steam in one step for known interval of times to enhance the surface area and develop interconnected porosity. The weight-loss behavior during steam activation of stabilized poly-blend at different temperatures, surface area and pore size distribution were studied to identify the optimum synthesis parameters. The results of surface characteristics were compared with those of activated carbon prepared by carbonization and activation in two steps. It was found that activation temperature has profound effect on surface characteristics. As activation temperature was raised from 800 °C to 1150 °C, surface area of activated carbon increased about three times. In addition to surface area, average pore diameter also increases with increasing activation temperature. Thus, activated carbon with high percentage of porosity and surface area can be developed by controlling the activation temperature during activation process.


1961 ◽  
Vol 16 (6) ◽  
pp. 1075-1077 ◽  
Author(s):  
Dean A. Miller ◽  
Stuart Bondurant

It has been suggested that alveolar stability is due, in part, to the presence of a noncellular alveolar lining which changes surface tension with changing surface area. Extracts of mammalian lungs manifest a decrease in surface tension with decrease in surface area. To compare surface characteristics with respiratory mechanics and anatomy, lung extracts were prepared from amphibians, reptiles, birds, and mammals. Lung extracts from mammalian lungs with true alveolar structure show typical surface tension-surface area characteristics, whereas other vertebrate lung extracts behave similarly to most other biological fluids. An alveolar lining layer with surface behavior similar to mammalian lung extracts would be expected to contribute to alveolar stability. Submitted on June 28, 1961


2014 ◽  
Vol 625 ◽  
pp. 98-101 ◽  
Author(s):  
Ali E.I. Elkhalifah ◽  
Mohammad Azmi Bustam ◽  
Azmi Mohd Shariff ◽  
Sami Ullah ◽  
Biruh Shimekit ◽  
...  

The present study investigates the effects of intercalation process of protonated primary, secondary and tertiary amines on structural and surface characteristics of sodium form of bentonite clay. For this purpose, sodium form of bentonite clay was prepared and then exchanged with mono-, di-and triethanolammonium cations via intercalation mechanism into the interlayer space of the clay. The prepared samples were characterized by XRD and BET techniques. An increase in the d-spacing of bentonite clay with the molar mass of amines was observed in their x-ray diffractograms, following the order of: triethanolamine > diethanolamine > monoethanolamine. The BET results showed a gradual decrease in the BET surface area with the increase in the molar mass of amines used. Based on the results obtained, it can be concluded that the molar mass of amines has significant effects on structural and surface properties of bentonite clay.


1972 ◽  
Vol 52 (4) ◽  
pp. 449-458
Author(s):  
J. T. MILLS

The maximum quantities of five seed treatment fungicides that adhered to seed of barley, buckwheat, crambe, flax, rape, sunflower, and wheat were determined and considered in relation to oil and moisture contents of seeds of the crops. Adhesion was related to the gross seed surface area per bushel, to fine surface features of the seed, and to the nature of the treatment material but not to number of seeds per bushel. Most adhesion was to rapeseed, which had a high gross surface area per bushel and a very rough surface. The fungicides, arranged in increasing order of adhesion to seeds, were Panogen Px, Vitaflo DB, Arasan 75, Manzate D, and Benlate T. Manzate D and Benlate T had much greater adhesion and smaller more friable particles than the other fungicides. Panogen Px depends for effectiveness on its volatility, thus less adhesion and larger aggregated particles are not factors limiting its use.


Sign in / Sign up

Export Citation Format

Share Document