2011-03-14

Meeting minutes _LWG_Geochemistry/Microbiology

Date: March 14, 2011 Time: 0930-1130

Attendee: Joerg Gelmacher, Chieh Peng, Carlos Alvares-Zarikian, David Fackler, Grant Banta, David Houpt, Lorri Peters, John Miller, and Bill Mills (layout presentation)

Agenda:

A. Chemistry lab re-modeling - counter space additions layout (Bill)

B. Summary of EXP330 cruise evaluation (Joerg)

C. Summary of EXP330 technical report (Chieh)

D. Summary of Technical Documentation status (Lorri)

E. Summary on Hand Held XRF report from EXP330 (Joerg)

Discussion:

A. Chem/MBIO lab remolding -Bill

1. It was identified that Chemlab needs more counter space. Bill M presented a solution by addingmini-extensions which are 90 degree from the current islands. These extensions will be placed where there are current small empty spaces under the counter. Current proposal is to add a 24”x30” countertop to a) SRA station, b)Dionex station, c)GC stations, and 12-18”x30-36” shelves to starboard side wall between each island, except the forward starboard side, where the oxygen bottles are located. It is agreed among the group the Maple wood will be used as countertop material, and T-slot extruded Al will be used as support.

2. All electrical lines and gas delivery system lines will be cleaned up during the tie-up period.

3. Chiller fan in the MBIO cold room is replaced with the new model. The report from ship is that it is still noisy, but the new unit is hanging off the ceiling, which free up the space in aft wall. The new unit is capable of reducing the room temperature without producing the ice storm like the old unit. It is an improvement overall. We should explore the usage of acoustic ceiling tiles to reduce the noise.

Action: The layout for additional extensions is agreed among the group, Bill will scope out material to be purchased. The project will be carried out during up-coming tie-up period.

B. Summary of EXP330 cruise evaluation - Joerg

1. Joerg went through the cruise evaluations from EXP330. The following issues were reported

a. ICP: Nb can not be measured, Ba and Y resulted in poor data

b. Ashing furnace was not able to reach desired temperature, which resulted in high error in LOI. This problem was not communicated among the technical staff and LO/ALO and staff scientist until toward the end of the cruise.

c. MBIO scientist was having problem doing cell counts due to small size of cells requires high power objective, which has always been a difficult task on a moving ship. In particular since the dye he used was also adsorbed by certain minerals. One suggestion is to use multi-dyeing method to better differentiate real cells from minerals. David H mentioned replacing Hg lamp with LED to assist in the multi-dye methods for the microscope, but it is in testing stage.

Action: See technical report summary

C. Summary of EXP330 Technical reports - Chieh

1. The group went through both Chemistry lab and Xray lab tech report from EXP330

a. New operating software was written and deployed for Coulometer during EXP330

b. Chris Bennight had gone through all instrumentation software in the chemistry lab to see if they are compatible with Window 7. Several vendors software are not. The operation system has reverted back to Window XP in those cases.

c. A batch of silver capsules were purchased for EXP320/321 for CHNS with the concept of analyzing TOC on CHNS. They were used during Exp. 323 and Exp. 327 with excellent results. Scientist enquired about this analysis during EXP330, however, we didn’t have any more silver capsules onboard. It has to be decided by the USIO Management if we want to carry the expensive silver capsule onboard as an inventory item, in case scientists want to measure TOC with the CHNS and especially request using these capsules.

d. GC-PFT was not working during most of EXP329. A method was developed by Mike B. toward the end of the expedition. A new column is sent to EXP334 and will be installed and tested during EXP334.

e. Chemistry lab inventory items were cleaned up and location codes were established and entered into AMS system.

f. Xray technician, during EXP330, found residue remained on the samples after using Delrin plug to crush samples. The vendor was contacted to find out if the Delrin material has been changed. We are waiting for the vendor to respond.

g. The ashing furnace for processing LOI was not reaching desired temperature of >1000C. This is a known problem, the ship power does not provide 240V which is needed for the furnace to reach maximum temp. A step transformer was used during previous expeditions to solve this problem, however, it was not used during EXP330. There was a communication breakdown between the technicians, LO/ALO, scientists, and staff scientist. The issue could have contributed to the observed high error in the LOI, and possibly poor data for some elements. A permanent transformer is ordered and will be sent to EXP335 to be installed with the furnace. However, careful tests carried out by Barnes during Exp. 330 revealed that the LOI error is caused by a weighing error (the small ratio of powder weight to crucible weight multiplying). This was fixed by increasing the amount of powder measured (from 1g to 5g), and increasing the amount of time the weighing was taking (the same setting was being used for the cahn and mettler - 200 counts, but the cahn samples ~20x faster, so the absolute length of measurement wasn't sufficient - counts have been increased to 1000 for the mettler). These two changes resulted in LOI RSD of ~ +-0.4% . The lab group therefore recommends that the revised method for LOI determination should be further tested during the next hard-rock Exp. 335 by igniting the powder to >1000C AND by using 5g powder (if enough material is available) and 1000 counts on the balance. The next lab group meeting after Exp. 335 will then review the results and decide if a recommendation shall be made to change our standard LOI methods accordingly.

D. Summary of Technical Documentation status - Lorri

1. Lorri gave an overview of the tech doc status.

2. Cumulus should host the most updated version of the tech doc.

3. Any editing and suggestion should send to Lorri. If a technician needs to obtain a word document, he/she should also contact Lorri.

4. Data uploader procedure should be included in the tech doc.

5. Instrument parameters should be included in the tech doc.

Action: New documents need to written and reviewed for instrument, please see attached tech doc status report.

E.Summary report of hand-held XRF unit form EXP330 scientists - Joerg

1. The results presented in this report indicate a much higher error when the measurement was done directly on the rock surface in comparison to powdered (more homogenized) press pellet .

2. However, the data presented in the report are confusing, especially due to 1) the lack of individual results , 2) the averaging of the measurements from multiple (different) samples, 3) the lack of raw data (or at least a direct reference how and where to find them.

3. The Group discussed the results of this report and decided that further studies (by scientists during upcoming expeditions and by research specialists on shore) are needed to access the proper application of the instrument.4. However, the instrument turned out to be very useful for qualitative analyses of sediments (particular carbonates)

Action:

a. We will ask scientists from EXP335 to conduct further testing with samples from Superfast.

b. We will send the unit back to IODP at the end of EXP335 for method development.