Hygroscopic substances include cellulose fibers such as cotton and paper , sugar, c a r a m e l , honey, g l y c e r o l , e t h a n o l , methanol,Activated alumina, sulfuric acid, many fertilizer chemicals,Silica gel, many salts including table salt , and a wide variety of other substances[7]. Zinc chloride and calcium chloride, as well as potassium hydroxide and sodium hydroxide and many different salts , are so hygroscopic that they readily dissolve in the water they absorb: this property is called deliquescence.
Table 1. Advantages of activated alumina source:wikipedia Fig A : images are of NaCl, calcium chloride, Activated alumina balls The Material used: On studying various Hygroscopic materials like calcium chloride, silica gel, common salt,etc. The next section Discusses the use of activated alumina for extraction of water. This surface area significantly high compared to various other hygroscopic materials like silica gel,etc.
The compound is used as a desiccant to keep things dry by absorbing water from the air and as a filter of fluoride, arsenic and selenium in drinking water. It is made of aluminium oxide alumina , the same chemical substance as sapphire and ruby but without the impurities that give those gems their colour.
It has a very high surface-area-to-weight ratio, due to the many "tunnel like" pores that it has. The Alumina balls where kept exposed to atmosphere for hours. The size of the balls was measured before exposing them and also after the completion of hours. It was observed that the size of the activated alumina balls increased from 3mm to 5mm. This rise in size is due to adsorption of moisture in the pores of the alumina balls.
The water in the air actually sticks to the alumina itself in between the tiny passages as the air passes through them. Then the Alumina Balls where kept in the Vacuum Oven for few hours. It was observed that the Alumina balls had returned back to their normal size. This process is called regenerating the desiccant.
Since they are regenerated they can be used for the same process again without requiring any further treatment. The water vapour released was condensed with the help of the condenser and was collected in vessel with a help of vacuum pump.
The experiment was performed in the college using instruments which consisted of a vacuum oven , condenser and a collecting vessel. The image of apparatus is seen in the figure 2. Fig 1: Laboratory set up The project was conducted on a daily basis for two to three weeks. Each day same procedure was followed and the collected water was tested to understand the water quality.
Hence, it is necessary to conduct drinking water quality analysis on the sample obtained by this method. Below are the comparisons are listed. The proposed method is qualitatively 90 80 70 60 50 40 30 20 10 0 Table 3 : comparison of desalination to the proposed process. Fig 2: Adsorption of moisture by Activated alumina. Time min 4 5. Many aquifers have been over- pumped and are not recharging quickly.
Although the total fresh water supply is not used up, much has become polluted, salted, unsuitable or otherwise unavailable for drinking, industry and agriculture. And the way you find that Is the degrees of freedom for the numerator is the number of categories And then for the denominators, the total number of data values minus the number of categories. So there were 36 data values minus the six metropolitan areas. So 30 is your degrees of freedom for the denominator.
So that should be enough to use a table. But I use a calculator and I wrote a program in here called inverse. I'm not going to show you how to how to write the program. You can youtube it if you wish. Um But this is what I do. So um I put in my area which is my alpha value, my degrees of freedom is five and then my degrees of freedom for the denominator is 30 and That gives me my critical value.
About 2. I call f. Okay so anything greater than 2. We reject the annual hypothesis that all the means are the same And anything less than 2. We failed to reject meaning the h not is true. Okay so the second step is to find the F statistic and there's a formula but it's a bit of a mess.
I always use software you know technology is a great thing. So if you go to stat and you can type in your data values. So there are six categories. And if you go to stat tests and then we're gonna go to the Unova test and then you just type in your columns separated by commas remember there were six columns, six data columns that we used and we need to make sure that all of them are in there and last one and then also you know make sure you separate those by commons, otherwise it's going to read it wrong.
So then um that gives us everything we need. The trial will follow two groups of patients through treatment lasting 8 weeks and 26 weeks, respectively, as it is too late to include a control arm.
Alexion improvised its response to the E. The company holds an month supply on hand from two production facilities and should be able to keep up with demand related to this E. Adler adds that it is too early for Alexion to comment on the commercial implications of the E. This story was the lead news story in the August Nature Biotechnology : [ html ] [ pdf ].
In our latest video for The Tyee , we look at a WHO program trying to address these issues by linking trials in over 90 countries together into one big global study. The idea is to provide a clear answer to which drugs are effective against COVID, as quickly as possible. A lot has happened since the National Institutes of Health announced preliminary results of their Remdesivir results last Wednesday. Most notably the FDA approved it for emergency use , meaning American patients can now be treated outside clinical trials.
The results announced were:. Those who received a placebo recovered in a median time of 15 days, The study included patients but the initial results are apparently based on the first of these. The Washington Post reports that two weeks ago the primary metric of the study was changed from the number of patients who died to the time it took them to recover. Another randomized control trial with patients published on the same day, did not find benefits.
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