Saturday, November 20, 2010

Groupon- a "no deal" deal

I hate Groupon! I was burned twice for the incompetent groupon so far. I purchased a $25 Gap coupon for $25 from Groupon so I can buy a gift for my dad. I got the gift and needed to exchange the sweater. Now Gap says we can not get the refund applied to a new sweater and that's how groupon works! So, no replacement/exchanage of your item if you use a groupon coupon.
Next time, I got a weekly cinema coupon- now weekly cinema went under. I lost my 4 tickets; only plus sign, Groupon did refunded the purchase price.

Wednesday, October 20, 2010

Low transfer speeds on Dockstar, but why?

Low transfer speeds on Dockstar, but why?
Format your Data Partition with XFS

mkfs.xfs /dev/sdX
Add it to /etc/fstab

/dev/sdX /mnt xfs noatime,logbufs=8,allocsize=128m 0 2
Create file /etc/rc.local.durchsatz with this content

blockdev --setra 16384 /dev/sdX
ifconfig eth0 txqueuelen 5000
echo deadline > /sys/block/sdX/queue/scheduler
then do

chmod 700 /etc/rc.local.durchsatz
Edit /etc/sysctl.conf and add the following line to the end of the file

vm.dirty_ratio=8
vm.dirty_background_ratio=5
vm.vfs_cache_pressure=50
vm.swappiness=100
net.core.netdev_max_backlog=5000
net.ipv4.tcp_sack=0
net.ipv4.tcp_timestamps=0
net.ipv4.tcp_fin_timeout=10
net.ipv4.tcp_tw_recycle=1
Reboot your device

Monday, August 09, 2010

Py-N-Oxide

1. Procedure

In a 1-l. three-necked flask equipped with a stirrer (Note 1), a thermometer, and a dropping funnel is placed 110 g. (1.39 moles) of pyridine. The pyridine is stirred, and 250 ml. (285 g., 1.50 moles) of 40% peracetic acid (Note 2) is added at such a rate that the temperature reaches 85° and is maintained there. After the addition, which requires 50–60 minutes, the mixture is stirred until the temperature drops to 40°.

A. Pyridine-N-oxide hydrochloride. The acetate is converted to the hydrochloride by bubbling a slight excess over the theoretical amount (51 g.) of gaseous hydrogen chloride into the reaction mixture by way of a 7-mm. gas inlet tube which replaces the dropping funnel in the reaction flask. The acetic acid and excess peracetic acid are removed by warming on the steam bath under vacuum (Note 3). The residual pyridine-N-oxide hydrochloride is purified by heating under reflux for 30 minutes with 300 ml. of isopropyl alcohol, cooling to room temperature, and filtering. The colorless crystals are washed with 50 ml. of isopropyl alcohol followed by 50 ml. of ether. The yield is 139–152 g. (76–83%) (Note 4), m.p. 179.5–181°.

B. Pyridine-N-oxide. The acetic acid solution is evaporated on the steam bath under the pressure of a water aspirator, and the residue (180–190 g.) is distilled at a pressure of 1 mm. or less in an apparatus suitable for collecting a solid distillate (Note 5). The vacuum pump must be protected with a Dry Ice trap capable of holding about 60 ml. of acetic acid, which distils as the pyridine-N-oxide acetate dissociates at low pressure. Heat is provided by an oil bath, the temperature of which is not allowed to rise above 130° (Note 6). The product is collected at 100–105°/1mm. (95–98°/0.5 mm.). The yield is 103–110 g. (78–83%) of colorless solid, m.p. 65–66° (sealed capillary). The base is deliquescent and must be stoppered immediately.

2. Notes
1. A convenient seal for stirring under vacuum (see (Note 3)) is made by running an 8-mm. glass rod, with propeller or paddle stirrer at the end, through the outside member of an 18/9 spherical joint which is inserted into a suitable rubber stopper. The inner member of the 18/9 spherical joint is then slipped over the stirrer and held in place with a piece of rubber tubing. This rotating seal may then be lubricated with a drop of oil. Alternatively, one may use a Trubore stirring system.

2. Becco peracetic acid (40%) was used. The composition and properties of this commercial preparation are described fully in Bulletin 4 of the Buffalo Electro-Chemical Company, Buffalo, New York. The manufacturer's recommendations for storing and handling should be followed. Experiments using proportionate amounts of 10% or 20% peracetic acid in acetic acid were equally successful. The strength of the peracetic acid, as well as the progress of the reaction, can be determined iodimetrically.

3. The vacuum evaporation proceeds much more smoothly and rapidly if the mixture is stirred mechanically during the process.

4. The submitters report that the same procedure is successful with four times the amounts given here. With the increased amounts, a water bath is used for cooling during the initial addition, which then requires about 45 minutes.

5. Caution! Before distillation, absence of peroxide should be established by test with potassium iodide.
The apparatus for distillation of solids in vacuum described in Organic Syntheses3 is satisfactory, as is a combination of standard taper flasks, short column, and adaptors.

6. It is imperative that the pressure be maintained at 1 mm. or lower. Decomposition is usually extensive at higher pressures; however, the removal of the acetic acid may be initiated at 5–10 mm. pressure. The oil-bath temperature must not exceed 130° if decomposition is to be avoided. A fore-run of 15–20 g., b.p. 90–98°/0.5 mm., can be saved and redistilled in combination with similar cuts from successive runs. About 9–10 g. (7%) of additional crystalline pyridine-N-oxide is obtained per run in this manner.

Trisyl azide; why this stuff is so expensive?

From US2006/0069286Al, 2,4,6-Triisoprorylbenzenesulfonyl azide synthesis:-

To a solution of triisopropylbenzenesulfonyl chloride (6.94 g, 22.9 mmol) in acetone (115 mL) at 0° C. was added a solution of NaN3 (1.64 g, 25.2 nnnol) in water (10 mL). The mixture was stirred for 30 min at 0° C. and then was warmed to rt and stirred for 1 h. The mixture was concentrated, diluted with water, and extracted with DCM(3x). The combined organic extracts were dried (Na2S04) and concentrated. The residue was purified by flash chromatography (EtOAclhexanes) to provide 6.71 g (95%) of the desired sulfonyl azide as a white solid. 1 H NMR (400 MHz, CDCI3): 7.22 (s, 2H), 4.05 (sept, 1=6.7, 2H), 2.93 (sept, 1=6.9, lH), 1.29 (d, 1=6.8, 12H), 1.27 (d, 1=6.9, 6H).

As you see, synmthesis is dead easy and starting materials are pretty cheap. So why the final product is commerically so expensive? Is it because of the patent or is it because safty hazard of the azide?

Monday, August 02, 2010

JP 32009872

2,6-Dimethyl-4-pyridone (2.1 g.) in 15 ml. HCl, 6.5 g. ICl in 5 mi., and 100 ml. H2O heated 3 hrs. at 90° and the product dild. with 300 ml. H2O and cooled gave 6.4 g. 2,6-dimethyl-3,5-diiodo-4-pyridone (I), m. 259-61°.  Similarly, 1 g. 2,6,4-Me2(H2N)C5H2N yielded 79% 4-NH2 analog of I,m. 155°; HCl salt, m. 258° (decompn.); 0.2 g. 4,2,6-Me2(HS)C5H2N yielded 0.55 g. 4-SH analog of I, m. 247° (decompn.).

Thursday, April 22, 2010

Sane way of setting up SBG901 with your own router










Recently I faced a complicated issue of interfacing Motorola SBG901 wireless cable modem which comes with all sort of bells and whistles but with the limitation of a single ethernet port. Having VOIP and linux server makes it imperative for me to connect the cable modem to a router (DIR-655 in this case).

SBG901 has an inbuilt DHCP server that needs to be disabled to have all my port forwardings to work properly from the router, however the modem manual does not indicate what to do to disable the inbuilt DHCP server.

After spending hours, I find out that you have to disable NATP mode. See the screenshots.





Tuesday, April 06, 2010

uscis contact mail ids

1. USCIS Service Center Inquiry Instructions - Aug 2009

The USCIS issued instructions (PDF 32.7KB) August 6, 2009 on how to follow up on cases pending at the USCIS service centers. These instructions should be followed by individuals and organizations inquiring about timelines and generic information. One should NOT rely on general information from the government for legal options, analysis of a particular situation, or advice on how to proceed in a particular immigration case.
First Step : Call NCSC's Toll-Free Number
The first step in the instructions is to call the National Customer Service Center (NCSC) at their phone number (1.800.375.5283). It is necessary to have the USCIS receipt number and other case-related, identifying information in order to make such inquiries.

It is suggested that one keep the name and/or ID number of the person with whom s/he speaks, as well as the date and time of the call. One should also keep any service request referral number, if there is action taken on the case.

Second Step : eMail Service Center after 30 days
If the NCSC has not been able to resolve the particular matter within 30 days, then it is possible to send an eMail to the service center that has the case. In order to use the eMail service, it is necessary to have the information regarding the initial call to the NCSC; that is, the name and/or ID number of the representative, date and time of the call, and the service request referral number. If no service referral was made, it is necessary to indicate why the NCSC did not take this action.
The eMail addresses for this purpose are as follows:

California Service Center : csc-ncsc-followup@dhs.gov
Vermont Service Center : vsc.ncscfollowup@dhs.gov
Nebraska Service Center : ncscfollowup.nsc@dhs.gov
Texas Service Center : tsc.ncscfollowup@dhs.gov

Third Step : eMail to USCIS Headquarters
If there is still no resolution in the case after 21 days of sending the eMail described in step two, it is possible to eMail the USCIS Headquarters Office of Service Center Operations. This eMail address is SCOPSSCATA@dhs.gov. The USCIS promises a response to these inquiries within ten days.

Conclusion : General Information No Substitute for Legal Advice

Potentially, the case follow-up procedures can be helpful for many situations. Each step requires a waiting time, however. In some situations, such as case denials with time-sensitive deadlines, it is not advisable to wait for NCSC action. There are deadlines (often only 30 days and sometimes 15 days) for challenging certain USCIS decisions. If a case is denied, or if one encounters serious problems otherwise, it is necessary to obtain proper legal advice and not assume that a call to the NCSC is all that is needed.
It should be noted that calls to the NCSC are answered by individuals who provide general immigration information based on scripts. Responses to one's inquiry should be considered only as a general guideline, and not as a substitute for proper legal advice. We at the Murthy Law Firm sometimes speak with individuals who wish to make an immigration filing, because they think that the NCSC told them they could do so. They may have been told that, in order to do what they wish to do, it is necessary to file a certain form. However, NCSC does not evaluate whether one is legally eligible to file, whether it is the correct procedure for that individual or family, or if other considerations exist that may completely change the equation. Speaking with a knowledgeable lawyer for case-specific, individualized advice as to one's immigration options is a safer and, actually, much less expensive option in the long run. The NCSC should be used for case follow up and general immigration information only.

Sunday, February 07, 2010

Blackberry with cheap data plan on T-mobile- possible.

Blackberry is one of the phones which consistently delivers very good voice quality and I was hooked onto this particular aspect of RIM devices when I first got my perl flip for Tmobile last year. Things went to downhill on that silly Perl Flip device fairly soon. Automatic reboots, occasional lock-ups become daily routine. Long painful story was shortened by 3 replacements and eventually a new Blackberry 8520 came as final replacement from Tmobile- class act!
Now, I jumped into googling about running my phone off the $10 web2go plan instead of $30 BIS data plan. The morale of the story I found over my hours of search is- anything with RIM involved (such as, BB messenger/BB maps/BB weather/BB App world) will refuse to work without a blackberry data plan. However, most of the other functionalities can work just fine with a regular data plan; with some tweak.
When my 8520 was shipped to me, it was not showing up as a RIM device at T-mobile.com account. So, I had no problem to choose a Samsung model with internet capabilities at T-mobile.com as my phone and successfully add $10 web2go plan to my account. In my blackberry, under settings, I went to advanced settings and under TCP/IP set my APN as internet2.voicestream.com. Now everything works fine- I used Opera mini 5 beta 2 and web browsing is smooth.
However, I really needed couple of apps from BB appworld. One is Ka-glom and another is Callblocker pro. So I had to chat with TMO rep to get BIS instead of web2go plan. I installed BB app world, installed the necessary apps and cancell my BIS plan and select a Samsung phone to add web2go plan into my account. Surprise! surprise- in a wrong sense. Nothing is working anymore. The phone can not access anything that requires data plan. So I went back to the settings and under advanced options I looked at host routing table aka HRT. All HRT entries has one thing in common, under APN it is using blackberry.net. I believe, once you have your blackberry provisioned with BIS, it won't work with a regular data plan just because of the altered HRT. In a non-provisioned BB, HRT stays blank. So I picked up a blank SIM card for TMo and rebooted my 8520 with it. Voila- HRT table is now blank. Removed the SIM card, rebooted my 8520 with original SIM card and HRT stays unaffected. So now, I have a data enabled blackberry and I do not have to pay 30 dollars per month for accessing my gmail app, google maps and unlimited browsing.