Trumpet Number one

Appendix one 

Page published 24th October 2024

Updated 3rd February 2025

ENZYMATIC CONVERSION OF CARBON DIOXIDE TO METHANOL BY DEHYDROGENASES ENCAPSULATED IN SOL-GEL MATRIX

 

WEATHER AS A FORCE MULTIPLIER

ENZYMATIC CONVERSION OF CARBON DIOXIDE TO METHANOL BY DEHYDROGENASES ENCAPSULATED IN SOL-GEL MATRIX Zhongyi JIANG , Hong WU , Songwei XU , Shufang HUANG State Key Lab. of C1 Chemistry and Chemical Technolgy, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China Introduction Due to the abundance of CO2 as the major greenhouse and the most oxidized form of carbon, the efficient utilization of CO2 has aroused much interest from fundamental research to application application. Herein, we report a novel and promising approach to convert carbon dioxide into methanol through consecutive reduction catalyzed by three different dehydrogenases. The whole process consists of three steps: reduction of CO2 to formate catalyzed by formate dehydrogenase (FateDH), reduction of formate to formaldehyde by formaldehyde dehydrogenase ( FaldDH), and reduction of formaldehyde to methanol by alcohol dehydrogenase (ADH). Reduced nicotinamide adenine dinucleotide (NADH) acts as a terminal electron donor for each dehydrogenase-catalyzed reduction. It is now well established that a wide variety of enzymes retain their characteristic reactivities and chemical functions when they are confined within the pores of the silica sol-gel derived matrix. The porosity of sol-gel glasses allows small molecules and ions to diffuse into the matrix while the enzymes remain physically trapped in the pores, and thus resulting in an enhanced probability of reaction due to an increase in local concentration of substrates within the nanopores. Our experiments demonstrated that when the above-mentioned three enzymes are encapsulated in the silica sol-gel matrix, the yield of methanol is considerably increased as compared to that in solution phase. Experimental The reaction was studied in the solution phase by using an enzyme stock solution that was comprised of 7mg/mL of FateDH, 2mg/mL of FaldDH, 2mg/mL of ADH dissolved in 0.1M phosphate buffer at pH7. Add 1.0 mL of the enzyme stock solution to 1.0 mL of NADH solution in a polystyrene cuvette such that the final concentration of NADH varied from 0.025 to 0.1M . The cuvette was covered with Parafilm to prevent the evaporation loss of methanol produced, and CO2 was then bubbled through the solution for 8 h to ensure that the reaction equilibrium was established. The concentration of methanol was determined by gas chromatography. A calibration curve was established for methanol aqueous solutions with known concentration of methanol ranging from 0.001 to 0.005M . To evaluate the concentration of methanol produced as a result of the enzyme-catalyzed reaction. 1.0μL of the final reaction solution was used for GC measurements. The concentration of methanol was calculated by using peak areas for the characteristic methanol band in the chromatogram. The sol-gel encapsulated samples were prepared as follows: Tetraethoxysilane (TEOS) was used as precursor for making the silica sol-gel. The initial sol was prepared by mixing 2.60g of TEOS , 1.10g of 3%(v/v) of HCl solution . The mixture was then vigorously mixed for 10 min to form sol. The gel were prepared by adding 1.0 mL of the stock enzyme solution to 1.0mL of the sol in a polystyrene cuvette. Typical gelation times are on the order of 10-30s. The cuvette was then covered with Parafilm and gel was allowed to age at 4℃ for 24 h. The aged gel was then put into a dialysis membrane using 250 mL of 0.1M phosphate buffer at pH7 as dialysis solution , and placed in refrigerator at 4℃ with frequent change of 0.1M phosphate buffer at pH7 The dialysis lasted 24-48 h to completely remove ethanol generated in the sol-gel process. 0.1 mL of NADH solution diffused into the gel by dialysis in the similar manner ( the final concentration of NADH varied from 0.025 to 0.1M ), the sample containing the gel and the NADH solution was left undisturbed for 48h. To this mixture , CO2 was then bubbled for 8h for production of methanol. The concentration of methanol produced was determined using GC by taking a 1.0μ L aliquot of the solution. Results and Discussion Table 1 shows the preliminary methanol yields in solution and sol-gel matrix. The overall yield of the reaction in solution is near to 100%. In sol-gels, the production yield of methanol is substantially decreased due to the distribution effect, stereo hindrance, diffusion resistance. Table1 Representative methanol yields in solution and sol-gel matrix Reaction Temperature ℃ NADH（μmol） Methanol yield（%） 25 100 98.0 37 100 100 Solution 37 150 94.8 25 100 30.0 37 100 91.9 Solution 37 150 42.2 It is also found that all four species ( i.e. FateDH, Fald DH, ADH,NADH) must be present to generate methanol. The introduction of chemical modification to the enzymes and the creation of mesoporous structure of gel by biomimetic synsthesis is under investigation. To sum up, the feasibility of enzymatic conversion of carbon dioxide to methanol is tentatively explored. The consecutive reduction of carbon dioxide by three different dehydrogenases encapsulated in sol-gel matrix results in enhanced yields for generation of methanol. This will open up a new avenue not only for on-site production of methanol from cheap raw material but also for efficient fixation of the greenhouse carbon dioxide. Acknowledgment This work was supported by the National Natural Science Foundation of China, under the contract 20176039 References (1). Obert R., Dave B.C.. J.Am.Chem.Soc.,1999,121,12192-12193. (2). Gill I., Ballesteros A..

Trends in Biotechnology ,2000,18:282-296. (3). Ellerby L M, Nishida C R, Nishida F et al. Science, 1992,255:1113-1115 Fuel Chemistry Division Preprints 2002, 47(1), 306

Weather as a force multiplier Weather as a Force Multiplier: Owning the Weather in 2025

 Miscellaneous Citation | Accession Number: ADA333462 |  Open PDF

Abstract:

In 2025, US aerospace forces can own the weather by capitalizing on emerging technologies and focusing development of those technologies to war fighting applications. Such a capability offers the war fighter tools to shape the battlespace in ways never before possible. It provides opportunities to impact operations across the full spectrum of conflict and is pertinent to all possible futures. The purpose of this paper is to outline a strategy for the use of a future weather modification system to achieve military objectives rather than to provide a detailed technical road map. A high risk, high reward endeavor, weather modification offers a dilemma not unlike the splitting of the atom While some segments of society will always be reluctant to examine controversial issues such as weather modification, the tremendous military capabilities that could result from this field are ignored at our own peril. From enhancing friendly operations or disrupting those of the enemy via small scale tailoring of natural weather patterns to complete dominance of global communications and counterspace control, weather modification offers the war fighter a wide range of possible options to defeat or coerce an adversary. Some of the potential capabilities a weather modification system could provide to a war fighting commander in chief CINC are listed in table 1. Technology advancements in five major areas are necessary for an integrated weather modification capability 1 advanced nonlinear modeling techniques, 2 computational capability, 3 information gathering and transmission, 4 a global sensor array, and 5 weather intervention techniques. Some intervention tools exist today and others may be developed and refined in the future.

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Author(s):

House, Tamzy J.; Near, James B., Jr.; Shields, William B.; Celentano, Ronald J.; Husband, David M.

Author Organization(s):

AIR WAR COLL MAXWELL AFB AL

Descriptive Note:

Research rept

Pagination:

53

SECURITY MARKINGS

Distribution:

APPROVED FOR PUBLIC RELEASE

Subject TermsCollapse  

Descriptor(s):

*WEATHER MODIFICATION, MILITARY OPERATIONS, MILITARY STRATEGY, MILITARY CAPABILITIES, MILITARY APPLICATIONS

Field(s)/Group(s):

Meteorology, Military Operations, Strategy and Tactics

Report Date:

1996 Aug 01

Go to link below to download full pdf file

https://apps.dtic.mil/sti/citations/ADA333462