Myanmar has the second largest area of mangrove forests in South East Asia while suffering high deforestation rates and forest degradation. However, monitoring results from existing studies in mangrove forests vary widely while specific estimates on carbon density for this forest type are deficient. Also, data from mangrove inventory plots used for the 2018 Myanmar forest reference level refer only to commercial timber and do not include other carbon pools. The results in this study based on four carbon pools allow for updating the emission factors in mangrove forests expressed in CO 2 from 125.43 ± 15.06 Mg ha –1 to 1 377.07 ± 67.04 Mg ha –1 for Ayeyarwady region (Pyapon, Pathein, Latputta districts) and 1 583.27± 75.18 Mg ha –1 for Tanintharyi region (Kawthaung, Dawei districts) and can be used in (sub)national or jurisdictional forest reference level for REDD+. In addition, the georeferenced biomass estimates are useful for the calibration of space-based models of biomass estimation.

SUMMARY Political and socioeconomic settings for policy decision-making about forests are increasingly complex and characterised by growing user demands, the strong influence of non-state actors and an expanding internationalisation of forest policy issues. In this context, efforts in information provision must produce data that are not only technically reliable and cost-efficient but also relevant to and accessible by stakeholders. Based on the experiences gained in national forest inventory projects as well as national forest programmes and forest policy processes in several countries, this paper proposes a set of principles and their application in key action areas of planning to help guide the process of designing national forest monitoring and inventory projects or programmes from the perspective of users of information in forest-related policy processes.

(1980). SYNTHESIS OF PHENOXYPHENYLATED 4,4″-DICARBOXY-p-TERPHENYLS. Organic Preparations and Procedures International: Vol. 12, No. 6, pp. 327-336.

High-temperature composites were successfully prepared from aminated polysulfone, polyphenylsulfone, and a rod-like polymer polybenzimidazole (PBI). The single glass transition temperature Tg and the absence of evidence for phase separation in scanning electron microscopy suggested that these systems formed so-called ‘molecular composites’. The enhanced miscibility between the polymer pairs was probably due to hydrogen bonding interactions. Compared with the matrix polymers themselves, these composites have improved values of Tg and thermal stability due to a synergistic effect upon incorporation of polybenzimidazole into the polymer matrices. Microcellular foams were successfully prepared from these composites. The foaming behavior and morphologies of the resulting composite foams were much more complicated than those of the pure polymers. In particular, they had unusual bimodal cell size distributions, and some open or partially open-cell structures.

A carboxylated polysulfone (C-PSF) was reacted with 3-(glycidoxypropyl)trimethoxysilane (GPS) in a sot-gel reaction to form hybrid networks. Specifically, GPS was grafted to the C-PSF chains at their epoxy ends by ring-opening reactions and then the methoxy silane groups at their other ends were crosslinked through the usual hydrolysis and condensation reactions. These C-PSF/GPS cross-linked binary networks are of interest in their own right, but this type of network was also used in the incorporation of polybenzimidazole (PBI) rigid-rod polymer to form a C-PSF/PBI/ GPS ternary composite. In this case, the network structures obtained by carrying out the same reaction in the presence of PBI chains successfully suppressed their undesirable segregation within the composite. The transparencies of the preparative solutions and the dried films indicated that the dispersion of PBI was maintained in these environments, presumably at the nano- or molecular level. The ternary composites were characterized using Fourier-transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), thermal mechanical analysis (TMA), and thermogravimetric analysis (TGA). Some of these composites were converted to closed-cell microcellular foams, which were then characterized in a preliminary way with regard to their morphologies.

Coil-like graft copolymers of poly(Am-co-B(1−m)) containing identical heterocyclic aromatic benzoxazole with trifluoromethyl-ethyl as the backbone and pendants of monohydroxl (Am) and/or bidecyloxyl (B(1−m)) on their phenylene ring were studied for luminescence properties. The copolymers were synthesized with molar fraction m ranging from 0, 0.25, 0.5, 0.75, to 1, and then dissolved and spun onto a Spectrosil® quartz slide or an indium-tin-oxide (ITO) substrate. The fluorescence properties of copolymers were investigated by ultraviolet–visible absorption covering 185 nm to 800 nm and photoluminescence (PL) emission excited at 363 nm. The PL results exhibited an excellent chromatic tuning, ranging from green to white emission as m decreased. Aluminum electron injectors were evaporated onto the copolymer/ITO unit making it into monolayer light-emitting diodes for current–voltage and electroluminescence (EL) responses. An emission threshold voltage of 6 V was achieved for all the monolayer copolymer devices. The Commission Internationale de l’Eclairage coordinates of the EL emission were from (0.25, 0.53) to (0.24,0.31) covering a wide visible range including white light emission.

Molecular composites were prepared from sulfonated modifications of polysulfone and polyphenylsulfone by incorporating relatively stiff polybenzimidazole (PBI) chains into them. The composites were characterized by Fourier-transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC), thermal mechanical analysis (TMA), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The FT-IR results demonstrated strong specific interactions between the sulfonated polymers and the PBI, which was presumed to be the reason for the enhanced miscibility observed. Miscibility was also indicated in the DSC and TMA results, by the presence of a single glass transition temperature (which was composition dependent), although there did appear to be a small degree of phase separation. TGA results showed improvements in the thermal stability of the polymer matrix because of the incorporation of PBI. Results from SEM were also consistent with considerable miscibility. Microcellular foams processed from these molecular composites had partial open-cell cell structures, with average cell sizes ranging from 0.2 to 5 μm, in unusual bimodal cell-size distributions.

This manuscript presents the results of a research project dealing with the processing of microcellular foams from molecular composites. The main goal of this work is the preparation, characterization, and evaluation of polymer-based foams. A variety of thermoplastic polymers have been evaluated with regard to the extent to which they can be formed into monolithic foams, and methods have been developed for toughening these foams. The primary mechanism for improving toughness and other mechanical properties is inclusion of rigid-rod polymers as dispersed phases. Both the thermoplastic host material and the molecular composites have been processed into the desired foams through extensions of the proprietary methods developed by Wright Materials Research Company. Part I of this series of papers presents the results of polybenzobisthiazole(PBZT)/polyetherketoneketone(PEKK) microcellular foams. The results show that the incorporation of the oriented rigid-rod polymers into a host thermoplastic matrix has given large improvements in mechanical and thermal properties of the foam. The properties of primary interest for optimization are of a mechanical nature, and for the anticipated structural applications include modulus, ultimate strength, maximum compressibility, impact resistance, and toughness. The microstructural details of the foams, which were monitored via standard microscopic techniques, were correlated with some of their properties.

Next generation microelectronic packaging requirements are driving the need to produce increasingly lower dielectric constant materials while maintaining high thermal stability and ease of processing. Important material requirements for these applications include low dielectric constant, high thermal, thermooxidative and dimensional stabilities, T-g above 350degreesC, low thermal expansion coefficient and low moisture uptake. Required dielectric constants will be between 2.0-2.4, with a progressive need for a figure of merit below 2.0. Our research efforts have focused on the synthesis and characterization of new polymer compositions with a view to meeting the objectives of imparting high thermal stability (degradation temperatures substantially higher than 350degreesC), low moisture uptake (less than 1%), solubility for processing in common organic solvents, as well as obtaining dielectric constants less than 2.5 and low thermal expansion coefficients. The logical extension of such an approach has recently resulted in some unique post-polymerization chemistry involving intramolecular rearrangement and crosslinking of the candidate polymeric materials to provide resistance to chemicals encountered during microelectronic packaging.

Native forests in Chile are subject to an ongoing process of degradation and destruction. In 1992, the Chilean government proposed a new law aimed at the recovery and sustainable management of native forests. However, the proposal, although amended several times has not yet been transformed into law. Powerful private interest groups such as the forest industry and environmental organisations have successfully advocated against one or more of the different proposals. Notwithstanding, recent developments suggest that the worst of the process might be over and a new law may be passed in the near future. Drawing on concepts from policy sciences (advocacy coalition framework, critical sub-sector model), the present work attempts to explain the dynamics in the policy formation process as a result of the clash of fundamentally opposing policy beliefs evident in a critical issue niche or critical sub-sector that blocked changes in the overall policy sub-system for years. However, the increasing availability of private policy instruments (e.g. forest certification) allowed for the removal of this issue from the discussion about statutory policy options and thus relieved the process from a long-standing deadlock.

Poly(p-phenylene benzobisoxazole) (PBO) has been synthesized in the presence of single-wall carbon nanotubes (SWNTs) in poly(phosphoric acid) (PPA) using typical PBO polymerization conditions. PBO and PBO/SWNT lyotropic liquid crystalline solutions in PPA have been spun into fibers using dry-jet wet spinning. The tensile strength of the PBO/SWNT fiber containing 10 wt % SWNTs is about 50% higher than that of the control PBO fibers containing no SWNTs. The structure and morphology of these fibers have been studied.