Articles in this journal
Natural Resources, Volume 12, pp 59-71; doi:10.4236/nr.2021.123006
LDH-phases become increasingly interesting due to their broad ability to be able to incorporate many different cations and anions. The intercalation of methanesulfonate and ethanesulfonate into a Li-LDH as well as the behavior of the interlayer structure as a function of the temperature is presented. A hexagonal P63/m [LiAl2(OH)6][Cl∙1.5H2O] (Li-Al-Cl) precursor LDH was synthesized by hydrothermal treating of a LiCl solution with γ-Al(OH)3. This precursor was used to intercalate methanesulfonate (CH3O3S−) and ethanesulfonate (C2H5O3S−) through anion exchange by stirring Li-Al-Cl in a solution of the respective organic Li-salt (90˚C, 12 h). X-ray diffraction pattern showed an increase of the interlayer space c' (d001) of Li-Al-methanesulfonate (Li-Al-MS) with 1.2886 nm and Li-Al-ethanesulfonate (Li-Al-ES) with 1.3816 nm compared to the precursor with 0.7630 nm. Further investigations with Fourier-transform infrared spectroscopy and scanning electron microscopy confirmed a complete anion exchange of the organic molecules with the precursor Cl−. Both synthesized LDH compounds [LiAl2(OH)6]CH3SO3∙nH2O (n = 2.24-3.72 (Li-Al-MS) and [LiAl2(OH)6]C2H5SO3}∙nH2O (n = 1.5) (Li-Al-ES) showed a monomolecular interlayer structure with additional interlayer water at room temperature. By increasing the temperature, the interlayer water was removed and the interlayer space c' of Li-Al-MS decreased to 0.87735 nm (at 55˚C). Calculations showed that a slight displacement of the organic molecules is necessary to achieve this interlayer space. Different behavior of Li-Al-ES could be observed during thermal treatment. Two phases coexisted at 75˚C - 85˚C, one with a reduced c' (0.9015 nm, 75˚C) and one with increased c' (1.5643 nm, 85˚C) compared to the LDH compound at room temperature. The increase of c' is due to the formation of a bimolecular interlayer structure.
Natural Resources, Volume 12, pp 73-90; doi:10.4236/nr.2021.124007
In the below-given paper, a holistic, multidisciplinary approach of goods consumption, the economics of recycling and recovery is unfolding, concisely structured, until 2013. The analysis was focused, in brief, on some economic models addressed to environmental issues, tax policies, welfare, waste management, and specifically on recycling and reuse economic modelling. Recycle is an established practice in many countries, while reuse is still under development. Reuse in many aspects is a more desirable option, as far as waste management concerns, and EU legislation seems to encourage this practice. Many industries, especially in the technology section, have developed recycle and reuse programs in order to gain an advantage, while some of them have set a target of zero waste in their production process.
Natural Resources, Volume 12, pp 91-107; doi:10.4236/nr.2021.124008
The present work focuses on the proximate physical and chemical profile of Opuntia ficus-indica mucilage, mechanically extracted from cladodes, a waste of pruning in traditional organic cactus pear orchards in Italy (San Cono, Sicily). The mechanical extraction increased the mucilage yield to 30% dry weight. Physical characterization concerns pH, viscosity, free acidity and density, useful for emulsifying capacity. Spectrophotometric analysis was applied to assess total carbohydrates, proteins, uronic acids, total polyphenols content and antioxidant capacity. DART-MS and SEM-EDX were performed to evaluate functional mucilage components and relative amounts of minerals, respectively. From the main results Opuntia ficus-indica by-product, in addition to the preponderant total carbohydrates content, shows the high concentration in calcium and potassium and a fair amount of health-promoting phytochemicals, which make it a good candidate for the different type of industrial applications.
Natural Resources, Volume 12, pp 108-123; doi:10.4236/nr.2021.124009
From April 2013 to April 2014, the average pH and water temperature of the Taisi oyster cultivation area (TS, Yunlin County, Taiwan) were 8.05 (7.35 - 8.45) and 24.7˚C (13.7˚C - 32.8˚C) (N = 8226) The average organic matter (OM) concentration at sites TS-A and TS-B were 6.9% ± 1.3% and 6.9% ± 1.2%, and the weight of drift sand was 40.3 ± 19.1 g/d/m2 and 28.5 ± 34.3 g/d/m2 (N = 27). Considerable sand drifting typically occurs during the southwest monsoon season in summer. The average OM concentration at five dunes from Zhuoshui estuary to Zengwun estuary was 23.9 ± 4.5 g/kg. The percentage of sand grain weight of 0.15 - 0.25 mm and 0.25 - 0.60 mm was 82.5% ± 14.2% and 10.5% ± 12.0%. In the spring and autumn of 2015, the average OM concentration at the eight intertidal zones from Hanbao to Cigu was 49.8 ± 34.1 g/kg (N = 177), and the OM concentrations at Huwei estuary and Hanbao and Fangyuan intertidal zones were relatively high. The OM concentration (95.3 ± 75.7 g/kg) of the low tide zone of Huwei estuary was the highest among all tidal zones. The OM concentration during spring (59.4 ± 41.7 g/kg, N = 95) was higher than that in autumn (39.1 ± 17.8 g/kg, N = 84). For sand grain size ranges 0.15 - 0.25 and 0.063 - 0.15 mm, the weight ratio of intertidal sediment was 39.4% ± 26.9% and 27.6% ± 20.1%, respectively. The broad and flat intertidal zone was marked by fine sand and long intertidal zone; the weight ratio of SGSs
Natural Resources, Volume 09, pp 413-428; doi:10.4236/nr.2018.912026
Transnational benefit sharing from the exploitation of Marine Genetic Resources’ (MGR’s) in Areas Beyond National Jurisdiction (ABNJ) presents a unique problem in international law. Proposals to govern MGR’s in ABNJ include leaving them unregulated, governance under the International Seabed Authority (ISA) or the Convention on Biological Diversity (CBD) or implementing a new international regime. This paper demonstrates that a hybrid solution for MGR governance under the ISA which is modeled on the CBD and The Nagoya Protocol (Nagoya), provides the most adroit solution to the problem of equal benefit and access to MGR’s for all States. This solution ensures adequate conservation of MGR’s, meanwhile fostering sustainable exploitation and maintaining equality in access, biodiversity and the sharing of financial and technological benefits amongst the internationalcommunity. Further, examining benefit sharing from bioprospecting under the CBD and Nagoya provides a foundation for a benefit-sharing regime in ABNJ under The United Nations Convention on the Law of the Sea (UNCLOS). Examining the CBD, Nagoya and UNCLOS demonstrates how benefits arising from exploitation of MGR’s in the high seas and deep bed should be included as a mandate of the ISA. This methodology is accomplished by focusing on bioprospecting for MGR’s and how the CBD and Nagoya facilitate access to the resource while ensuring that the host State or community benefits from granting access. As the CBD and Nagoya focus on benefit sharing in light of national sovereignty, and UNCLOS regulates in areas beyond national jurisdiction, the ISA is perfectly placed to adopt the principles of the CBD and Nagoya and provide a mechanism to ensure that MGR’s in ABNJ are adequately conserved and the benefits arising from their exploitation equitably shared.