| Author |
Message |
    
Dr. Joseph Arditti
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 25, 2003 - 11:37 am: | 
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Steve,
Thank you. |
Stephen Kemp
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 25, 2003 - 10:04 am: |
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Actually, I found the compiled version online anyway:
http://members.nuvox.net/~on.jwclymer/rh.html |
Stephen Kemp
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 25, 2003 - 10:01 am: |
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I don't have a compiler available to me now but there are calculators available at http://fridgetech.com/calculators/
Scroll down to Psychrometrics section (about halfway down the page) and there are calculators for RH & DP. For example, the first one will calculate both RH and DP given altitude plus both dry and wet bulb temps. |
Dr. Joseph Arditti
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 25, 2003 - 09:32 am: |
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I do not know how to do that. What does the program do? If it calculates RH, dew points etc. I would appreciate a working copy. |
Stephen Kemp
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 25, 2003 - 08:20 am: |
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> How do we use the source code?
It has to be compiled using a Java compiler to produce an executable file
Cheers...Steve |
Peter Fowler
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 25, 2003 - 04:28 am: |
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Java Source code on Relative Humidity
I personally have trouble with BASIC language.
Found this on one of my searches.
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Dr. Joseph Arditti
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 25, 2003 - 04:15 am: |
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How do we use the source code? |
Peter Fowler
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, September 24, 2003 - 09:42 pm: |
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Java Source code for measuring Relative Humidity
About 30 years since I heard of Clausius-Clapapeyron equation.
Peter
/* Clausius-Clapeyron Calculation */
import java.awt.*;
import java.applet.*;
import java.util.*;
public class rh extends Applet {
double t1, t2, rh1, rh2, dew, vapor;
TextField t1_text, t2_text, rh1_text, rh2_text, dew_text, vapor_text;
Button calc_button;
Label label;
public void init() {
setLayout(new GridLayout(9,2)); // 9 rows, 2 columns
add(new Label("Temperature 1 (C)"));
t1_text=new TextField("25",10);
add(t1_text);
add(new Label("%RH (at T1)"));
rh1_text=new TextField("50",10);
add(rh1_text);
add(new Label("Temperature 2 (C)"));
t2_text=new TextField("40",10);
add(t2_text);
add(new Label()); add(new Label());
add(new Label());
calc_button = new Button("Calculate");
add(calc_button);
calc_button.setBackground(Color.yellow);
add(new Label()); add(new Label());
add(new Label("%RH (at T2)"));
rh2_text=new TextField(10);
add(rh2_text);
add(new Label("Dew Point (C)"));
dew_text=new TextField(10);
add(dew_text);
add(new Label("Vapor Pressure (mm Hg)"));
vapor_text=new TextField(10);
add(vapor_text);
}
public boolean action(Event event, Object arg) {
t1 = new Double(t1_text.getText()).doubleValue();
rh1 = new Double(rh1_text.getText()).doubleValue();
t2 = new Double(t2_text.getText()).doubleValue();
t1 = t1 + 273;
t2 = t2 + 273;
double p0, deltaH, R;
p0 = 7.5152E8;
deltaH = 42809;
R = 8.314;
double sat_p1, sat_p2;
sat_p1 = p0 * Math.exp(-deltaH/(R*t1));
sat_p2 = p0 * Math.exp(-deltaH/(R*t2));
vapor = sat_p1 * rh1/100;
rh2 = (vapor/sat_p2)*100;
dew = -deltaH/(R*Math.log(vapor/p0)) - 273;
System.out.println("sat_p1 = " + sat_p1);
System.out.println("sat_p2 = " + sat_p2);
System.out.println();
rh2_text.setText(Double.toString(rh2));
dew_text.setText(Double.toString(dew));
vapor_text.setText(Double.toString(vapor));
return super.action(event, arg);
}
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Dr. Joseph Arditti
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, September 24, 2003 - 04:42 pm: |
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anthropomorphic - so, if plants never 'want' what makes some orchid species and hybrids then produce offshoots or flowers when devoid of roots & leaves and left somewhere high and dry. Often apparently 'dead' pseudobulbs seem to have enough vigour left to develop their growing points despite lack of water, roots and leaves.
The stress or condtions you descibe cause physiological changes which lead to what you describe.
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Wolfgang H. Bandisch
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, September 24, 2003 - 04:26 pm: |
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Joe,
anthropomorphic - so, if plants never 'want' what makes some orchid species and hybrids then produce offshoots or flowers when devoid of roots & leaves and left somewhere high and dry. Often apparently 'dead' pseudobulbs seem to have enough vigour left to develop their growing points despite lack of water, roots and leaves.
Most other plants, I think, will just depart to their heaven and not replicate themselves before finally shrivelling away. |
Dr. Joseph Arditti
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, September 24, 2003 - 02:15 pm: |
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wanted to add that if the plant produces offshoots (keikis) that this could be some kind of sign of stress.
This is possible because stress mayu affect hormonal relations and production.
The plant wants to replicate itself.
This is anthropomorphic. Plant never "want." They have no senses like people or even animals.
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Wolfgang H. Bandisch
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, September 24, 2003 - 12:43 pm: |
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Peter,
I wanted to add that if the plant produces offshoots (keikis) that this could be some kind of sign of stress. The plant wants to replicate itself.
This ability is used successfully by commercial nurseries. The dry pseudobulbs (canes) of Dendrobium (with all roots cut off) are placed on a wire racks, not watered, and without fail most of them will produce at least one or two offshoots (keikis)from their growing points before the cane eventually dries up completely. |
Stephen Kemp
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, September 24, 2003 - 12:12 pm: |
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Another thing to keep in mind about humidity is that it is 'relative'. That is, the warmer the temperature, the more moisture can be suspended in the atmosphere. This means that 60% humidity in summer represents a higher level of moisture in the air than 60% in winter.
I guess this also means that as the air cools, humidity (as a percentage) will naturally rise but the amount of moisture in the atmosphere might not actually change.
Also, as the air cools in the higher regions of PNG , the cloud layer will fall and humidity will further increase in the cloud forest areas.
I hope I got this right.
Cheers...Steve |
Wolfgang H. Bandisch
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, September 24, 2003 - 08:52 am: |
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Peter,
the humidity 'thing' is, to my mind, often misunderstood. Here on the Papuan side we have a dry season and it hardly ever rains from April to December. So humidity is extremely low. Then from July to August we have the 'laurabada' winds (trade winds) that dry out the place even more.
Up on the mountains clouds will form every afternoon and these 'may' shed some rain, but not necessarily so. According to reports received it had not rained up on Mt. Albert Edward for the past 3 weeks. BUT the clouds carry enough moisture to feed the plants.
Even high altitude species can take a warm to very warm day but need rapid cooling off during the afternoon and an even sharper drop in temperature at night. This is achieved, in part, with the clouds settling in. On many days of the year it does rain without fail high up on the mountains, mostly a 'drizzly' kind of rain (like you have in GB!). The rains start in the early afternoon.
So the humidity can be anything during the day but should be high at night. |
Peter Fowler
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, September 24, 2003 - 08:16 am: |
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Wolfgang, Very interesting information and great photo. They sure are beautiful flowers.
We have had a very hot spell this year; hottest since records began. I kept the windows open all the time, and the door open some nights in the greenhouse, when it was really hot. Humidity would have been low, but I kept it high in the day's, as I dont work.
What would the humidity be like in the wild, where it grows and does it rain every day at a certain time?
I have reduced feeding it ,like you suggested in an earlier email. A lot of the large canes are producing off-shoots of smaller canes. I noticed this happens normally from the herbarium photos, from Leiden University.
Thanks again |
Wolfgang H. Bandisch
Rating: 
Votes: 1 (Vote!) | | Posted on Tuesday, September 23, 2003 - 09:30 pm: |
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Peter,
I have recently seen this species growing high up in the mountains at Dup Creek, about 2,300 m above sea level, in the Western Highlands. I post a picture of that plant herewith. You can see that it flowers on the leafless pseudobulbs. The plant can be pendant or erect. Up on the mountains it can get pretty cold at night but during the day temperatures can be a pleasant low twenties (Celsius, that is).
I have also found this species at the Tari Gap (similar elevation) growing terrestrial in the alpine grasslands.
So, what this means is that the species requires significant fluctuations between day and night time temperatures, and the light intensity at those elevations is rather high as well. Something that cannot be easily replicated in a greenhouse in Alton, I suppose.
 |
Wolfgang H. Bandisch (Wolfgang)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, July 22, 2003 - 11:50 pm: |
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That section of Dendrobium will ONLY flower on leafless pseudobulbs, same as D. smilliae, D. anosmum (the warm growing relatives). I found that PNG species are doing quite well with very little fertilizer.
where the species grows in PNG day time temperatures can reach the mid twenties (degrees Celsius), with a sharp drop in night temperature to nearer 10 degrees Celsius. |
Peter Fowler (Cuthbert)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, July 22, 2003 - 11:12 pm: |
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I have a very large plant of Dendrobium subclausum ssp. subclausum, which will not flower. It is mounted on a large tree-fern slab and comprises of 50+ thin canes. Some of the older canes are producing off-shoots, similar to kei-keis, but not quite the same. I have seen herbarium pictures (Netherlands) and the plant seems to flower on old leafless canes. The great majority of my plant is in leaf.
It is grown with maximum light (Cattleya levels) and fed 1 in 4 with balanced feed; not fed in Winter and watered less. Minimum temp. 12C.
Why won't it flower?
Peter Fowler
Alton, UK Birthplace of William Curtis.
It is great to be a member of such a professional looking group |
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