Influence of Doubled CO2 on Ozone via Changes in the Brewer–Dobson Circulation

In this short note, the effect of enhanced circulation due to doubling CO2 on ozone is investigated. The difference of Brewer–Dobson circulation (BDC) between the doubled CO2 and control run from an idealized atmospheric general circulation model is added to the BDC climatology derived from National Centers for Environmental Prediction—Department of Energy Reanalysis 2 (NCEP2) from 1979 to 2002. Then it is used to drive the California Institute of Technology/Jet Propulsion Laboratory (Caltech/JPL) two-dimensional chemistry and transport model. The results reveal that the total ozone increases by 7 and 3.5 Dobson units (DU) in the high latitudes of the Northern and Southern Hemispheres, respectively, and decreases by 4 DU in the Tropics as a result of the increase in BDC associated with doubled CO2. If the change of eddy mixing coefficients after doubling CO2 is also considered, the total ozone will increase by 6.5 and 3 DU in the high latitudes of the Northern and Southern Hemispheres after combining both effects from the change in BDC and eddy mixing coefficients

Thermolabile protecting groups in metal-organic frameworks : a thesis presented in partial fulfilment of the requirements of the degree of Doctor of Philosophy in Chemistry at Massey University, Manawatu, New Zealand

Prior to the work carried out for this thesis, there were no publications in which bpy was used as a ligand backbone, or in which a carboxylate was incorporated into a MOF using a TPG. Also, to the best of our knowledge there are no examples in the literature of an ethyl carbamate TPG in MOFs. In this thesis the range of TPG protected ligands has been expanded to include 1,4-bdc (Chapter 2) and bpy (Chapters 4 and 5). The bpy-NHBoc and bpy-TBE materials are the first examples of N-donor type ligands protected by TPGs. Furthermore, the bpy-TBE ligand is the first example of a TPG protected carboxylate in a MOF. In Chapter 2, 1,4-bdc-NH2 was protected as both the ethyl carbamate and the tert-butylcarbamate, giving 1,4-bdc-NHCOOEt and 1,4-bdc-NHBoc, which there then incorporated into a MOF-5-type framework. It was envisaged that thermolysis of the carbamate esters could generate an isocyanate group, though this was not expected for 1,4-bdc-NHBoc due to the tendency of tert-butylcarbamates to decompose to the amine. Despite thermolysis on the TGA apparatus only generating the amine, it was found that thermolysis under vacuum enabled not only enabled ~ 60 % conversion of the ethylcarbamate to 1,4-bdc-NCO, but also a ~20 % conversion of the tert-butylcarbamate to 1,4-bdc-NCO. The MOF-5 analogues in this work also proved sufficiently stable to survive the thermolysis conditions with little discernible effect on the porosity of the material. In Chapter 3, 1,3-bdc-NH2 was protected as both the ethyl carbamate and the tert-butylcarbamate, giving 1,3-bdc-NHCOOEt and 1,3-bdc-NHBoc, which there then incorporated into a lon-e-type framework. It became apparent the lon-e was a poor choice in MOF for use with TPGs as the framework was prone to collapse from desolvation, and it was not possible to thermolyse the materials without complete collapse of the MOFs. In Chapter 4, bpy-NH2 and bpy-CO2H were protected with TPGs to give bpy-NHBoc and bpy-TBE respectively. The ligands were combined with bpdc and zinc to obtain the BMOF-1-bpdc analogues MUF20-Aβ and MUF20-Aγ. Whilst the thermolysed materials MUF20-Aβt and MUF20-Aγt demonstrated significant gas uptakes compared to their protected counterparts, comparison of MUF20-Aβt with the directly synthesised material MUF20-Aβ’ revealed significantly higher uptakes than the thermolysed materials. This discrepancy indicates that the BMOF-1-bpdc/MUF20 framework is partially degraded under thermolysis conditions. These results strongly imply that this framework is not compatible with TPGs. However, TPGs did allow for the installation of a carboxylate group into the BMOF-1-bpdc/MUF20 framework which was not obtainable through direct synthesis methods. In Chapter 5, bpy-TBE was combined with btb and Zn/Cu to obtain Zn-DUT-23-TBE and Cu-DUT-23-TBE. These materials were then thermolysed to produce Zn/Cu-DUT-23-CO2H, materials that were not able to be directly synthesised using bpy-CO2H. Unfortunately, the thermolysed materials demonstrated significant decreases in uptakes compared to their protected counterparts. However, the TPG containing materials also had markedly lower uptakes than the parent Zn-DUT-23 and Cu-DUT-23 materials, which has been attributed to pore collapse. This partial pore collapse may have sufficiently weakened the MOF framework to increase its sensitivity to the thermolysis conditions, resulting in a much larger decrease in uptake than would have been the case with a defect free material. The results of this thesis revealed that MOF stability is a key factor in the compatibility of a material. Specifically, the MOF must be resistant to solvent removal and subsequent heating at elevated temperatures for extended periods. This is most clearly observed in Chapter 3, where the lon-e materials were very susceptible to solvent removal, and later were completely collapsed by thermolysis. These findings have led to the recommendations outlined in section 6.2 for the screening of MOFs for their compatibility with TPGs

Cobalt and copper-based metal-organic frameworks synthesis and their supercapacitor application

In this study, two different metal-organic frameworks (MOFs) were synthesized using copper and cobalt metal ions with benzenedicarboxylic acid (bdc) as a common ligand. The prepared MOFs were characterized using X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy-energy dispersive spectroscopy. Also, the electrochemical characteristics were analyzed using cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy methods. Structural characterizations indicate that Co-bdc MOF is composed of three-dimensional non-uniform colloids and Cu-bdc MOF has a regular three-dimensional cuboidal structure, possessing good crystalline structure. The Cu-bdc MOF exhibited a maximum specific capacitance of 171 F/g, while Co-bdc MOF showed 368 F/g at the current density of 1 A/g. The solution resistance for the Co-bdc MOF was 0.09 Ω in comparison to 1.25 Ω for the Cu-bdc MOF. Also, the Co-bdc MOF demonstrated better cycling performance by retaining 85 % of its capacity after 2000 charge-discharge cycles. In contrast, the stability of the Cu-bdc MOF was lower, with only 78 % retention in capacity. Conclusively, the Co-bdc MOF demonstrated superior specific capacitance, lower resistance, and enhanced cyclic stability in 3 M KOH electrolyte system

The Backgrounds Data Center

The Strategic Defense Initiative Organization has created data centers for midcourse, plumes, and backgrounds phenomenologies. The Backgrounds Data Center (BDC) has been designated as the prime archive for data collected by SDIO programs. The BDC maintains a Summary Catalog that contains 'metadata,' that is, information about data, such as when the data were obtained, what the spectral range of the data is, and what region of the Earth or sky was observed. Queries to this catalog result in a listing of all data sets (from all experiments in the Summary Catalog) that satisfy the specified criteria. Thus, the user can identify different experiments that made similar observations and order them from the BDC for analysis. On-site users can use the Science Analysis Facility (SAFE for this purpose. For some programs, the BDC maintains a Program Catalog, which can classify data in as many ways as desired (rather than just by position, time, and spectral range as in the Summary Catalog). For example, data sets could be tagged with such diverse parameters as solar illumination angle, signal level, or the value of a particular spectral ratio, as long as these quantities can be read from the digital record or calculated from it by the ingest program. All unclassified catalogs and unclassified data will be remotely accessible

Basin Development Challenges - Stakeholder Consultation Workshop Report - Volta River Basin

Report from consultation workshop conducted on November 25-26, i.e. before the beginning of CPWF phase 2.The overall objective of this workshop was to consult key stakeholders knowledgeable about the proposed Volta BDC on how research can best contribute to tackling the BDC. In the Volta, the proposed BDC was “Rainwater management and small reservoirs in Northern Ghana and Burkina Faso”. A brief description of the proposed BDC, taken from the CPWF’s 2010 – 2013 Medium Term Plan, was sent to orientate the participants before the workshop (see Annex 1). Participants were invited to the workshop to provide advice on how research can best contribute to the BDC, thus helping the CPWF Management Team design the BDC research program (Step 3 in Table 1). The specific objectives are shown in Figure 1 together with the process that was followed to achieve them. The process used elements of Participatory Impact Pathway Analysis (PIPA)1 and incorporated lessons learned in conducting similar consultations in other basins

Peroxymonosulfate activation by different synthesized CuFe-MOFs: application for dye, drugs, and pathogen removal

In this study, three CuFe-MOFs were successfully synthesized by a solvothermal process by changing the ratio of solvents, salts, or temperature. These MOFs named CuFe(BDC-NH2)R, CuFe(BDC-NH2)S, and CuFe(BDC-NH2)D showed rod-shaped, spindle-like, and diamond-like structures, respectively. The CuFe(BDC-NH2)D and CuFe(BDC-NH2)S were found to exhibit an improved PMS activation for Rhodamine B removal attaining levels around 92%. Their effective removal capability was investigated as a function of the pH, catalyst dosage, and the effect of the application of UV radiation. The best degradation system was photo-assisted activation of PMS when CuFe(BDC-NH2)D and CuFe(BDC-NH2)S were used. Under these conditions, the degradation of a mixture of antibiotic and anti-inflammatory drugs (sulfamethoxazole and antipyrine) was evaluated with the results revealing the total degradation of both drugs after 1 h. A higher antibacterial activity was attained with the system CuFe(BDC-NH2)R/PMS due to the high copper content with respect to the others.Ministerio de Ciencia e Innovación | Ref. PCI2022-132941Ministerio de Ciencia e Innovación | Ref. PID2020-113667GBI00Xunta de Galicia | Ref. ED431C 2021-4

Poly[[aqua­tris­(μ-benzene-1,4-dicarboxyl­ato)tricobalt(II)] methanol monosolvate monohydrate]

The asymmetric unit of the title compound, {[Co3(C8H4O4)3(H2O)]·CH3OH·H2O}n, consists of four crystallographically independent Co cations, four benzene-1,4-dicarboxyl­ate (bdc) anions, two water and one methanol solvent mol­ecule. Two of the Co cations and two of the bdc anions are located on centres of inversion, whereas all other atoms are located in general positions. In the crystal, two Co atoms are only fourfold coordinated by three O atoms from three bdc ligands and by one O atom from one coordinated water mol­ecule, while a third Co atom is coordinated by four O atoms from four bdc ligands within a strongly distorted tetra­hedral geometry. The other two Co cations are octa­hedrally coordinated by six O atoms from six bdc anions. The Co cations are linked by the bdc anions into a three-dimensional framework. From this arrangement, cavities are formed in which additional methanol and water mol­ecules are embedded