Posts by jeff

    I think Dr. Mizuno is dealing with a high standard metalworks shop so they have high rates. Perhaps is not easy for him to find a more economic shop to get the nuts drilled, if that is the problem really. Is hard to imagine what else could be the problem to open it.

    As people have stated previously, stainless steel galls easily; it also has a tendency to work harden, making drilling difficult. Some vacuum hardware utilizes silver coated threads to avoid this problem. For example, the threads on VCR fittings are typically plated with silver. I don't know what machining facilities Mizuno has, but if he can get hold of a vertical mill and carbide tooling it should be possible to either drill or mill off the damaged hardware (assuming it is nuts/bolts). I have some experience machining stainless, and the combination of rigid a setup, carbide tooling, and appropriate coolant works well.


    Jeff

    Well, having changed the filaments, rebaked the QMS and pumped it down for a couple of days we are now at 3.4x10-8mB - and the foreline trap only arrived today and isn't fitted.


    So maybe- depending on your roughing pump you don't have to worry. They are mostly to trap water vapour anyway.


    Rather than worry about oil contamination, I purchased a Pfeiffer MVP-202-3DC dry diaphragm pump. Pfeiffer Vacuum recommends this type of fore pump for their TMU-262 T/M pump. Based on Pfeiffer's data, it should be possible to attain 1e-8 mbar with this combination of pumps.

    Prototype half-scale cell 40 x 300 mm. The heater is a 150 watt cartridge inserted in the thermowell. I'll initially assemble it without Ni mesh, for vacuum testing and bake out. The ports are both 3/8" Swagelok, welded to the end caps.



    From where did you order the thermowell? Most of the ones I saw are designed for high pressure usage, entailing a wall thickness much greater than is necessary for our use.

    I understand that. There has to be some sort of transition.


    Most paper is flimsy, and sealing/smoothing the inside seems awkward, so wondering how it was done. I mean, I am actually trying to replicate as best as possible.

    When building a flow calorimeter I machined 1/2" plexiglass to accept the square hole pattern of the fan on one side and a 2" PVC pipe on the other side. Plexiglass can be bonded to PVC with the plumber's cement sold at hardware stores.


    Jeff

    You need to be lucky if spending anything under $5k IMO. The spec I have (and was seen working before collection) is elderly, and getting it back into top-line condition will take a little time. Fortunately we have a software wizard who is working on updates for the system, After some initial concerns at least it has responded to a bake out and some tender loving care. If you buy an old one, seeing it working is vital, because the filaments etc may be burnt out. I replaced the vacuum gauge with an ebay find, as it was flakey, but they can also be stripped and serviced, which I will do with the old one, as you need two- one for the mass spec and one for the reactor. A little practical engineering knowledge is vital I think. You also need to be sure you get one configured for low-mass, preferably a machine that has been used for helium leak detection or similar. All QMS systems are not identical.

    There is a local company: SRS that advertises a line of RGA QMAs starting at $3700 for a new unit.


    https://www.thinksrs.com/products/rga.html.


    I have not looked into all the details, but they may work for LENR needs. Pfeiffer Vacuum also makes what appears to be a nice unit, although it's approximately 2x as expensive.


    Jeff

    This is what I had thought as no mention of bake out gases was done in either video, and I hoped that was only an omission. For me it was clear that without the capacity of doing gas analysis, as Jed has insisted since the paper was published, there was no much hope of quick success.eff

    I do not think you can do this experiment without a mass spectrometer. You have no way of knowing whether you have cleaned the material and removed all water, nitrides and carbon dioxide. You are working blind.

    If one were to build a "reasonably priced" system that included <1e-7 mb vacuum system, a mass spectrometer, and a flow calorimeter, would it look like what is shown in the attachment? I am in the process of determining what such a system would cost, but before proceeding further I would like some consensus that the proposed system meets the requirements for a MIzuno replication.

    Hi Jeff.


    I'm afraid it's al gone now. As I have to buy 20 pieces a time right now I can't help you unless a few other people step up. Sorry -I would love to help.

    Alan,


    Sigh...


    If there is sufficient interest in ordering another set of 20 let me know. I'll buy a set then.


    Jeff

    So I have heard, from other people.

    I found an interesting paper that details the reduction of NiO in H2 at different temperatures. The paper reports that both the percentage of NiO reduced, as well as the resulting surface morphology are strongly dependent on the reduction temperature. Low temperatures result in incomplete reduction with induction times of many minutes, while high temperatures yield nearly 100% reduction occurring in seconds. So the NiO reduction process may do more than simply remove oxide. It may also produce a NAE supportive surface.


    https://pubs.acs.org/doi/abs/10.1021/acs.jpcc.5b04313.


    Jeff

    A few comments regarding a fan-based flow calorimeter. The temperature delta between input and output will not be linear with respect to the power dissipated internally. As the air inside the calorimeter is heated it expands and produces a back pressure against the fan. So there are two factors affecting back pressure: a static back pressure and one that is temperature rise dependent. Typical fan performance curves show a decrease in airflow as back pressure increases. It's possible, of course, to work with a non-linear power vs. temperature rise curve by first running a calibration over the desired range of power levels. However, changes in the ambient temperature or variations in fan performance will introduce errors.


    The other approach is to construct a fan controller that guarantees a constant thermal mass flow. This can be done by placing a pair of diodes, one resistively heated and one not heated, in the inlet airstream. The forward voltage drop across each diode is then sent to an amplifier circuit that generates a variable DC voltage to power the fan. The temperature delta between the two diode junctions is proportional to the thermal mass of air moved by the fan, since the heated diode is cooled somewhat by the passing airflow. A plot of power vs. temperature rise then yields a nearly linear relationship. Note that DC power is supplied to the heater, so precise V and I measurements are possible. If anyone is interested I can provide circuit details and possibly PC boards.

    Regarding welding of SS: TIG welding is the preferred method. I had an exhaust system for a homebuilt aircraft fabricated of .040" wall thickness SS tube, and the results were really good. One word of caution: the welder stated that back purging is necessary to prevent oxidation on the reverse side.


    Depending on how the cell is constructed, it may be possible to purchase all the needed components pre-welded. For example, LDS Vacuum will fabricate custom length Conflat nipples. End flanges with the appropriate connections are available off the shelf. These include either VCR or Swagelok fittings. Take a look at their website for more details.

    Prototype half-scale cell 40 x 300 mm. The heater is a 150 watt cartridge inserted in the thermowell. I'll initially assemble it without Ni mesh, for vacuum testing and bake out. The ports are both 3/8" Swagelok, welded to the end caps.



    Looks good and very well made. Several questions: What size Conflat flanges are those? Also, the Conflat nipple looks longer than the standard size. Did you have one custom fabricated? Is the sheath heater secured via a Swagelok ferrule or is the long interior tube a closed end affair into which the sheath heater is inserted?

    To all,


    Thanks for your inputs and suggestions.


    I found a vendor, Isowater, that sells D2O for $779 per kg. They state that the D2O is refined, so hopefully that means it is also de-ionized. Most hydrogen generators require DI water to work properly. I once contacted United Nuclear to ask whether their D2O is de-ionised but never got a reply.100 gms of D2O may not be enough to sufficiently fill the reservoir in the hydrogen generator. However if 500g is sufficient I would be willing to sell the unused D2O to help defray costs.


    If there is one set of three Ni mesh I would be interested in purchasing a set for $400.00, I believe. If none are available, please put me down on a to-buy list. BTW, the volume of my replication setup is much smaller than that used by Mizuno, so excess power (if any) will be commensurately less.


    Several people have stated concerns about placing a thermocouple inside the chamber. I plan on avoiding this problem by using a fused quartz outer tube and an IR thermometer to monitor directly the temperature of the Ni mesh. An inconel sheathed cartridge heater (available from Omega ) will be placed inside the rolled mesh and will be separated from the mesh inside an alumina tube. In previous experiments I did use an internal and exposed heater element (Kanthal) and encountered no outgassing problems. Those experiments were run at 800-1200C, so at the much lower temperatures used in Mizuno replications, an exposed heater element may not cause problems with outgassing or metal vapor pressure.


    Jeff

    Wow! I have been away for only a few months and I see all this new discussion. Where to begin...

    I definitely plan on attempting a Mizuno replication, and already have most of the equipment from previous experiments. Here is a brief overview.

    1. Deuterium source: Parker Balston H2PEM100 hydrogen generator. Need help finding a source for D2O.

    2 Vacuum pump: Welch model 1400, good for roughing but will not reach vacuum level given by Mizuno. There are commercially available getters that can reduce water vapor and other contaminants, and these may allow roughing pump vacuum levels to work. I'll investigate.

    3. Gas/vacuum manifold, reuse existing equipment but add a metering valve to permit setting the D2O pressure to within +/-0.1 Torr. The system is plumbed with a 0-10 Torr baratron.

    4. Flow calorimeter, Already have one that implements a closed-loop thermal mass flow feedback to give a linear power vs. temperature rise relation. Has demonstrated the ability to resolve <1watt.

    5: Reaction vessel: will use 2.75" conflat hardware with Cu gaskets. All connections will either be welded (preferable) or high temperature silver solder brazed (OK for temperatures below ~400C). The plan is to use a cartridge heater that operates at atmospheric pressure but is coaxially situated inside the reaction cell.

    6: Power source for heater. Lambda LLS9040, 0-80V, 20A. It should be possible to use a heater with a 120V power rating 2x what I need and then operate at 0-80V.

    7: Data logging: Keithley model KUSP3108 and OEM furnished acquisition software.

    8: Ni mesh: hopefully someone can point me in the right direction.

    9: Pd: The stuff is really expensive, and most vendors will not sell to individuals. One possibility is to buy Pd bullion which is available in sub ounce denominations. Any suggestions here?


    Well, that's a start.


    Jeff

    A team from Russia, Dubinko, et al, has successfully utilized MD methods to demonstrate the existence of discrete breathers in NiH systems. This is the next logical step in characterizing realistic 3-D NiH systems, and has the potential to identify atomic configurations that are candidates for an NAE environment.


    See the following thread: http://www.quantumgravityresea…allic-hydrides-1.7.19.pdf


    Now I can (perhaps) justify investing in a desktop supercomputer, downloading LAMMPS, and start experimenting.


    Jeff

    For simple differential thermometry, consider wiring two thermocouples in series, with the polarity reversed. The output of the series string will then be proportional to the temperature difference between the two junctions.

    A pair of thermocouples reverse connected will only be accurate if the temperature difference is zero. The reason for this is that the Seeback coefficient is not a linear function of temperature. So if TC #1 is at 300C and TC #2 at 301C the voltage difference will not be the same as of TC #1 is at 500C and TC#2 is at 501C. Consult the following URL to see how the Seeback coefficient varies with temperature. For a small differential temperature delta a linear assumption may be acceptable.


    https://www.google.com/search? q=J+thermocouple+graph&site=webhp&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwjS1b3jmKPTAhVO0GMKHa-UDFUQsAQILQ&biw=1338&bih=847#imgdii=GhM165JLsS8NnM:&imgrc=xhxM153nEHAGXM:

    Experiments and experimenters are very welcome here.


    A number of years ago I had the opportunity to build a 1000V, 50A pulse generator using IGBTs. Pulse width was fixed at ~ 5.7 us with a rep rate from zero to 5000 pps. Proper gate drive voltage and current are key to making IGBTs turn on and off properly. Gate driver ICs are available from several manufacturers, as are pulse isolation transformers that permit stacking or bridging of IGBTs to obtain voltages higher than can be sustained by a single device. As was previously mentioned, it is important to maintain isolation between the input and output in order to avoid unwanted Ldi/dt voltages from appearing in the low voltage circuits. Separate grounds are essential, and here the isolation transformers are a help. I have used this pulse generator to heat a Celani type setup, but did not observe any excess heat.