PRETREATMENT EFFECTS ON THE SURFACE CHEMISTRY AND MORPHOLOGY OF ALUMINIUM

2006 ◽  
Vol 20 (25n27) ◽  
pp. 3611-3616 ◽  
Author(s):  
B. WITHY ◽  
M. HYLAND ◽  
B. JAMES
Keyword(s):  
Surface Morphology ◽  
Surface Chemistry ◽  
Sulphuric Acid ◽  
Water Immersion ◽  
Active Surface ◽  
The Other ◽  
Boiling Water ◽  
Atmospheric Conditions ◽  
Pretreatment Effects ◽  
Chemical Pretreatments

Chemical pretreatments are often used to improve the adhesion of coatings to aluminium. XPS and AFM were used to study the effect of these pretreatments on the surface chemistry and morphology of Al 5005. Four pretreatments were investigated, an acetone degrease, boiling water immersion, and two sulphuric acid etches, FPL and P2. Degreasing had no affect on surface morphology and simply added to the adventitious carbon on the surface. Boiling water immersion produced a chemically stable pseudo-boehmitic surface that was quite porous. The acid etches produced porous pitted surfaces similar to each other but significantly different to the other surfaces. The surface chemistry of the acid etched surfaces was variable and dependant on atmospheric conditions on removal from etch due to the very active surface that the etch produced.

scholarly journals Dormancy Breaking inOrmosia arboreaSeeds

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Edilma Pereira Gonçalves ◽  
Franklim Sales de Jesus Soares ◽  
Sérgio dos Santos Silva ◽  
Débora de Souza Tavares ◽  
Jeandson Silva Viana ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Urban Areas ◽  
Seed Quality ◽  
Water Immersion ◽  
The Other ◽  
Boiling Water ◽  
Seedling Production ◽  
Dormancy Breaking ◽  
Santa Cruz ◽  
Study Species

Ormosia arboreais a tree species planted in urban areas and used to restore degraded areas. Its seeds are dormant and propagation is difficult. This study compares different dormancy breaking methods and physiological seed quality and seedling production. The seeds were germinated in sand in the laboratory of the Universidade Estadual de Santa Cruz, Ilhéus, Bahia, Brazil. The following dormancy breaking treatments were applied: control (intact seeds), 100°C water immersion; boiling water immersion followed by 24 hours of soaking; scarification with number 100 and number 50 sandpaper opposite from root emergence; sulfuric acid immersion for 1 hour, 50, 45, and 30 minutes. Seed immersion in 100°C and boiling water did not break the dormancy. The study species showed a greater vigor of seedling when its seeds were submitted to treatments associated with tegument rupturing by sandpaper or sulfuric acid. On the other hand, seed scarification with sulfuric acid for 1 hour, 50, 45, and 30 minutes or sandpaper favored seed germination and vigor.

Choose you own scientific experiment: Triggering debris flows and flash floods

2016 ◽  
Author(s):  
Thea Turkington
Keyword(s):  
Debris Flows ◽  
Flash Floods ◽  
The Other ◽  
Background Information ◽  
Atmospheric Conditions ◽  
Scientific Experiment

Landslides and flash floods result in many fatalities around the globe. Understanding what triggers these events is therefore vital, although how to approach this problem is not straight forward. After background information for the experiment and some guidelines, two options are presented to learn more about the triggers of debris flows: (A) using rainfall or (B) the atmospheric conditions. You can then choose the option that appears more useful and interesting to you (you can always go back and read the other experiment afterwards). The article then ends with a reflection on the results.

Annual Variability in Summer Evapotranspiration and Water Balance at a Subarctic Forest Site

1994 ◽  
Vol 25 (5) ◽  
pp. 331-344 ◽  
Author(s):  
Peter M. Lafleur
Keyword(s):  
Water Balance ◽  
Daily Precipitation ◽  
The Other ◽  
Forest Site ◽  
Net Radiation ◽  
Atmospheric Conditions ◽  
Surface Moisture ◽  
Equilibrium Evaporation ◽  
Subarctic Forest ◽  
Single Regression

Evapotranspiration (ET) and precipitation were measured during five summers (1989-1993 inclusive) at a subarctic forest site near Churchill, Manitoba, Canada. Mean daily ET varied from 2.14-3.18 mm d−1 during the five summers, while mean daily precipitation (P) ranged from 1.46-3.15 mm d−1. Yearly variability in summer ET was most influenced by availability of surface moisture, then by atmospheric conditions (i.e. temperature), and least of all by net radiation. In four of the five years total summer ET exceeded P resulting in significant soil water deficits and in the other year summer ET and P were similar in magnitude. The use of equilibrium evaporation (EE) as a predictor of ET was explored. Separate relationships between ET and EE were computed for all five years. Three statistically dissimilar groups of equations were found: 1989/1990, 1991/ 1992, and 1993. A single regression equation describing all years is presented.

III.—On the Reduction of Ferric Iron (1) by Sulphurous Acid and (2) by Zinc Dust

1913 ◽  
Vol 32 ◽  
pp. 12-16
Author(s):  
Alexander Charles Cumming ◽  
E. W. Hamilton Smith
Keyword(s):  
Sulphuric Acid ◽  
Carbonate Rocks ◽  
Ferric Iron ◽  
Zinc Dust ◽  
The Other ◽  
Additional Contribution ◽  
Large Excess ◽  
Other Hand

So many papers have appeared on this subject that some apology seems desirable before making an additional contribution. The amount of published work on reduction with sulphurous acid is in itself an indication that many workers have found difficulties. It has been shown that the reduction does not take place in presence of large excess of hydrochloric or sulphuric acid, but the reduction will still occur while the reaction of the solution is strongly acid. On the other hand, Hillebrand (“Analysis of Silicate and Carbonate Rocks,” U.S. Bulletin, 442, p. 113) states if the solution after addition of sulphite is red in colour, it is too alkaline and acid must be added.

scholarly journals Integration of cooking and vacuum cooling of carrots in a same vessel

2012 ◽  
Vol 32 (1) ◽  
pp. 187-195 ◽  
Author(s):  
Luiz Gustavo Gonçalves Rodrigues ◽  
Darlene Cavalheiro ◽  
Franciny Campos Schmidt ◽  
João Borges Laurindo
Keyword(s):  
Cold Water ◽  
Textural Properties ◽  
Boiling Water ◽  
Integrated Process ◽  
Atmospheric Conditions ◽  
Final Temperature ◽  
Single Vessel ◽  
Vacuum Cooling ◽  
Feasible Alternative ◽  
Integrated Processes

Cooked vegetables are commonly used in the preparation of ready-to-eat foods. The integration of cooking and cooling of carrots and vacuum cooling in a single vessel is described in this paper. The combination of different methods of cooking and vacuum cooling was investigated. Integrated processes of cooking and vacuum cooling in a same vessel enabled obtaining cooked and cooled carrots at the final temperature of 10 ºC, which is adequate for preparing ready-to-eat foods safely. When cooking and cooling steps were performed with the samples immersed in boiling water, the effective weight loss was approximately 3.6%. When the cooking step was performed with the samples in boiling water or steamed, and the vacuum cooling was applied after draining the boiling water, water loss ranged between 15 and 20%, which caused changes in the product texture. This problem can be solved with rehydration using a small amount of sterile cold water. The instrumental textural properties of carrots samples rehydrated at both vacuum and atmospheric conditions were very similar. Therefore, the integrated process of cooking and vacuum cooling of carrots in a single vessel is a feasible alternative for processing such kind of foods.

An Easy Approach for Obtaining Superhydrophobic Surfaces and their Applications

2019 ◽  
Vol 813 ◽  
pp. 37-42
Author(s):  
Amani Khaskhoussi ◽  
Luigi Calabrese ◽  
Edoardo Proverbio
Keyword(s):  
Surface Morphology ◽  
Large Scale ◽  
Adhesion Force ◽  
Industrial Applications ◽  
Contact Angles ◽  
Boiling Water ◽  
Superhydrophobic Surfaces ◽  
Acid Mixture ◽  
Short Term Treatment ◽  
Water Contact

Three different methods were used to obtain nature-inspired superhydrophobic surfaces on aluminum alloys: short-term treatment with boiling water, HF/HCl and HNO3/HCl concentrated solution etching. Afterwards a thin octadecylsilane film was deposited on all pre-treated surfaces. The surface morphology analysis showed that each method allow to obtain a specific dual nano/micro-structure. The corresponding water contact angles ranged from 160° to nearly 180°. The adhesion force between the water droplets and superhydrophobic surfaces were evaluated. The specimen etched with HF/HCl acid mixture solution showed the lowest adhesion. However, the boiling water treatment sample was characterized by the highest adhesion. Furthermore, the relationship between hydrophobic behavior and surface morphology was discussed compressively. In addition, the electrochemical measurements show that the different superhydrophobic surfaces have an excellent anti-corrosion performance evidencing promising results suitable to obtain large-scale nature-inspired superhydrophobic surfaces for several industrial applications.

Effect of pressure on thermal insulation in humans wearing wet suits

1988 ◽  
Vol 64 (5) ◽  
pp. 1916-1922 ◽  
Author(s):  
Y. H. Park ◽  
J. Iwamoto ◽  
F. Tajima ◽  
K. Miki ◽  
Y. S. Park ◽  
...  
Keyword(s):  
Temperature Gradient ◽  
Water Temperature ◽  
Heat Loss ◽  
Thermal Insulation ◽  
Heat Production ◽  
Water Immersion ◽  
The Other ◽  
Body Parts ◽  
Metabolic Heat ◽  
Healthy Males

The present work was undertaken to determine the critical water temperature (Tcw), defined as the lowest water temperature a subject can tolerate at rest for 3 h without shivering, of wet-suited subjects during water immersion at different ambient pressures. Nine healthy males wearing neoprene wet suits (5 mm thick) were subjected to immersion to the neck in water at 1, 2, and 2.5 ATA while resting for 3 h. Continuous measurements of esophageal (T(es)) and skin (Tsk) temperatures and heat loss from the skin (Htissue) and wet suits (Hsuit) were recorded. Insulation of the tissue (Itissue), wet suits (Isuit), and overall total (Itotal) were calculated from the temperature gradient and the heat loss. The Tcw increased curvilinearly as the pressure increased, whereas the metabolic heat production during rest and immersion was identical over the range of pressure tested. During the 3rd h of immersion, Tes was identical under all atmospheric pressures; however, Tsk was significantly higher (P less than 0.05) at 2 and 2.5 ATA compared with 1 ATA. A 42 (P less than 0.001) and 50% (P less than 0.001), reduction in Isuit from the 1 ATA value was detected at 2 and 2.5 ATA, respectively. However, overall mean Itissue was maximal and independent of the pressure during immersion at Tcw. The Itotal was also significantly smaller in 2 and 2.5 ATA compared with 1 ATA. The Itissue provided most insulation in the extremities, such as the hand and foot, and the contribution of Isuit in these body parts was relatively small. On the other hand, Itissue of the trunk areas, such as the chest, back, and thigh, was not high compared with the extremities, and Isuit played a major role in the protection of heat drain from these body parts.

Preparation of Chitosan-Alginate/PES Pervaporation Membranes for Bioethanol Dehydration

2015 ◽  
Vol 1123 ◽  
pp. 182-186 ◽  
Author(s):  
Mumpuni Asih Pratiwi ◽  
Ronny Windu Sudrajat ◽  
Sri Sutanti ◽  
Heru Susanto
Keyword(s):  
Surface Morphology ◽  
Surface Chemistry ◽  
Composite Membrane ◽  
Membrane Surface ◽  
Composite Membranes ◽  
Solution Concentration ◽  
Wave Number ◽  
Water Mixture ◽  
Coating Solution ◽  
Degree Of Swelling

In the last decade pervaporation membrane has become an antractive dehydration processs for azeotropic ethanol-water mixture. In this paper, chitosan-alginate/polyethersulfone (PES) composite membranes were prepared (by coating method) characterized as pervaporation membranes. The composite membranes were then examined to purify ethanol-water mixture. The characterization included degree of swelling both in water and ethanol, permeability measurement, surface morphology (by SEM) and surface chemistry (by FTIR). The results show that the increase in concentration of coating solution increases the degree of swelling in the water on the one hand, whereas the permeability and the degree of swelling in the ethanol decreases on the other hand. The highest permeability was obtained for the composite membrane prepared from a coating solution concentration of 1% with the ratio of chitosan to alginate was 0,33. The surface chemistry shows that the increase in concentration of chitosan - alginate solution increases the intensity of a specific wave number of C-O and C-N groups. Surface morphology indicates that the PES membrane surface is clearly covered by chitosan - alginate mixture. Performance examination demonstrates that the composite membrane prepared by 3% a coating solution (with the ratio of chitosan to alginate 3) can increase the bioethanol concentration from 95.5% to 99.6%.

scholarly journals II. On the solvent power of liquid cyanogen

1872 ◽  
Vol 20 (130-138) ◽  
pp. 67-70 ◽  
Keyword(s):  
Copper Wire ◽  
The Other ◽  
Boiling Water ◽  
Small Fragment ◽  
Gutta Percha ◽  
Solvent Power

In the following experiments a number of stout tubes of refractory glass of the annexed shape were employed. Each tube was closed at one end, and had a flanged mouth at the other. The limb A was 11/2 inch long, the limb B 2 inches, and C 7 inches. In making the experiments, each tube was first filled, to an extent of 51/2 inches of its length, with highly dried crystals of mercuric cyanide; a small fragment of asbestus* was then pushed tightly against the end of the cyanide by means of a thin rod of gutta percha, and the bend of the tube cleaned by means of a slender brush. A number of taper plugs of gutta percha were previously made by softening, the end of a rod of that substance in boiling water and then chilling it ; and loops of thin copper wire were also prepared for the purpose of securing the plugs.

Unexpected Pyramid Texturization of n-Type Ge (100) via Electrochemical Etching: Bridging Surface Chemistry and Morphology

2018 ◽  
Vol 282 ◽  
pp. 94-98
Author(s):  
Graniel Harne A. Abrenica ◽  
Mikhail V. Lebedev ◽  
Hy Le ◽  
Andreas Hajduk ◽  
Mathias Fingerle ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Surface Chemistry ◽  
Photoelectron Spectroscopy ◽  
Chemical Etching ◽  
Electrochemical Etching ◽  
Spectroscopic Techniques ◽  
X Ray ◽  
Etching Behavior ◽  
Effect Of Oxygen

We report on the (electro) chemical etching behavior, surface morphology and composition of n-type Ge (100) in acidic halide solutions using various analytical and spectroscopic techniques. The use of an integrated (electro) chemical etching chamber connected to X-ray photoelectron spectroscopy instrument to exclude the effect of oxygen from atmosphere is highlighted.

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