Growing American Rubberexplores America's quest during tense decades of the twentieth century to identify a viable source of domestic rubber. Straddling international revolutions and world wars, this ...unique and well-researched history chronicles efforts of leaders in business, science, and government to sever American dependence on foreign suppliers. Mark Finlay plots out intersecting networks of actors including Thomas Edison, Henry Ford, prominent botanists, interned Japanese Americans, Haitian peasants, and ordinary citizensùall of whom contributed to this search for economic self-sufficiency. Challenging once-familiar boundaries between agriculture and industry and field and laboratory, Finlay also identifies an era in which perceived boundaries between natural and synthetic came under review.
Although synthetic rubber emerged from World War II as one solution, the issue of ever-diminishing natural resources and the question of how to meet twenty-first-century consumer, military, and business demands lingers today.
Green synthesis and nanomaterials have been the current trends in biomedical materials. In this study, Piper chaudocanum L. leaf extract-doped ZnO nanoparticles (PLE-doped ZnO NPs), a novel ...nanomaterial, were studied including the synthesis process, and the biomedical activity was evaluated. PLE-doped ZnO NPs were synthesized by the co-precipitation method, with differences in the synthesis procedures and dosages of the extract. The X-ray diffraction, Fourier transform infrared, scanning electron microscopy, energy dispersive X-ray spectroscopy, Brunauer–Emmett–Teller, ultraviolet-visible diffuse reflectance spectroscopy, and photoluminescence spectrum analysis results showed that the biosynthesized PLE-doped ZnO NPs were pure and in a hexagonal wurtzite phase. The PLE-doped NPs were synthesized by adding the extract to the zinc acetate solution before adjusting the pH and exhibited the smallest size (ZPS50 was 22 nm), the richest in the surface organic functional groups and the best optical activity. The highest antibacterial activity against P. aeruginosa and S. aureus was observed at 100 µg/mL of ZPS50 NPs, and the inhibition zone reached 42 and 39 nm, respectively. Moreover, ZPS50 NPs showed a moderate effectiveness against KB cancer cells with an ICsub.50 value of 43.53 ± 2.98 µg/mL. This present study’s results suggested that ZPS50 NPs could be a promising nanomaterial in developing drugs for treating human epithelial carcinoma cells and infectious illnesses.
The environment has been significantly impacted by the rubber industry through the release of large quantities of wastewater during various industrial processes. Therefore, it is crucial to treat the ...wastewater from the rubber industry before discharging it into natural water bodies. With the understanding that alarmingly depleting freshwater sources need to be preserved for future generations, this paper reviews the status of the rubber industry and the pollution caused by them, focusing mainly on water pollution. The review pays special attention to the recent advancements in wastewater treatment techniques for rubber industry wastewater categorizing them into pre-treatment, secondary, and tertiary treatment processes while discussing the advantages and disadvantages. Through a comprehensive analysis of existing literature, it was determined that organic content and NH4+ are the most frequently focused water quality parameters, and despite some treatment methods demonstrating superior performance, many of the methods still face limitations and require further research to improve systems to handle high organic loading on the treatment systems and to implement them in industrial scale. The paper also explores the potential of utilizing untreated or treated wastewater and byproducts of wastewater treatment in contributing towards achieving several United Nations sustainable development goals (UN-SDGs); SDG 6, SDG 7, SDG 9, and SDG 12.
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•Forecasted global industrial rubber market expansion is at CAGR of 5.2% by 2026.•Rubber industry uses high volumes of water in production (e.g. 20–50 L/1 kg of Crepe rubber, 50–60 L/1 kg of block rubber).•On average 20 tonnage manufacturing process generates 410 m3 of toxic effluent per day in a rubber factory.•Conventional techniques are inadequate to treat wastewater up to discharge standards.•Conventional to advanced treatment techniques used are reviewed in this paper.
In the twenty-first century, land deals in the Global South have become increasingly prevalent and controversial. Transnational access to arable land in impoverished "land-rich" countries in Latin ...America, Sub-Saharan Africa, and Southeast Asia highlights the link between the shifting geopolitics of economic development and problems of food security, climate change, and regional and international trade. Drawing on ethnographic and archival research, Upland Geopolitics uses the case of Chinese agribusiness investment in northern Laos to study the unbalanced geography of the new global land rush. Connecting the current rubber plantation boom to a longer trajectory of foreign intervention in the region, Upland Geopolitics reveals how legacies of Cold War conflict continue to pave the way for transnational enclosure in a socially uneven landscape. Upland Geopolitics is freely available in an open access edition thanks to TOME (Toward an Open Monograph Ecosystem) and the generous support of Indiana University. DOI: 10.6069/9780295750507
Zinc oxide (ZnO) is a fascinating wide band gap semiconductor material with many properties that make it widely studied in the material science, physics, chemistry, biochemistry, and solid-state ...electronics communities. Its transparency, possibility of bandgap engineering, the possibility to dope it into high electron concentrations, or with many transition or rare earth metals, as well as the many structures it can form, all explain the intensive interest and broad applications. This review aims to showcase ZnO as a very versatile material lending itself both to bottom-up and top-down fabrication, with a focus on the many devices it enables, based on epitaxial structures, thin films, thick films, and nanostructures, but also with a significant number of unresolved issues, such as the challenge of efficient p-type doping. The aim of this article is to provide a wide-ranging cross-section of the current state of ZnO structures and technologies, with the main development directions underlined, serving as an introduction, a reference, and an inspiration for future research.
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This work is focused on the recycling of natural rubber industry waste by means of thermo-mechanical devulcanization. With that aim, tests were carried out in an industrial twin-screw ...extruder, at different barrel temperatures, ranging from 80 to 220 °C. The extrusion was done with a screw profile specifically designed for the devulcanization process. The extent and quality of devulcanization were evaluated through the measurements of crosslink density, soluble fraction and Mooney viscosity, and by using the Horikx diagram. Results showed that a high degree of reclaiming (˜90%) was obtained, independently of the barrel temperature. The samples with the best devulcanization quality, i.e. the samples with a more selective sulfur bond scission, were found to be those treated at a lower input temperature. This was explained by the effect of the rubber homogenous self-heating which contributes to the local increase of the material temperature, during the devulcanization process. Moreover, it was found that the properties of the devulcanized rubber/virgin rubber blends were not significantly affected by the addition of the treated rubber. Results suggest that the entire natural rubber industry waste could be recycled into new competitive products, with low energy consumption. This would present a real contribution to the industrial recycling and thus a noticeable improvement of the environment.
Agroforestry is known to significantly improve long-term land productivity, potentially enhancing the ability to cope with climate stress. However, there is limited information regarding the accurate ...monitoring of greenhouse gases (GHGs) in rubber-based agroforestry systems. Before GHGs can be accurately estimated, the diurnal variations and suitable sampling times must be studied to reduce the uncertainty of the manual static chamber method. In this study, the soil GHGs emitted from conventional single-row (SR) and improved double-row (DR) rubber plantations were compared across the dry and wet seasons in Hainan, China. A total of 1728 GHG samples from a field trial were collected, analyzed, and related to environmental factors. The results demonstrated that the diurnal fluxes of COsub.2 in rubber plantations were likely to remain fluctuating, with the maximum typically occurring during the night-time and daytime hours of the dry and wet seasons, respectively. A clearer double-peak (around 2:00 and 14:00) during the dry season and a daytime peak (14:00) during the wet season of the Nsub.2O were recorded. In addition to the commonalities, different seasons and different types of GHGs and rubber plantations also differed in their detailed fluctuation times and ranges; therefore, the determination of suitable sampling times should not ignore these factors in certain cases. Based on this study, it was determined that the late afternoon (16:00–18:00) was the suitable sampling time of soil GHGs in rubber plantations, instead of the most common morning times (with an underestimation of 25% on average). In addition, the air humidity during the dry season and the soil temperature during the wet season were both positively correlated with GHGs (p < 0.05). This study highlights the significance of accurately monitoring soil GHGs in rubber-based agroforestry systems, providing a basic reference for the development and management of climate-smart land use practices in rubber plantations.
The rubber tree, Hevea brasiliensis, is a species native to the Brazilian Amazon region and it supplies almost all the world's natural rubber, a strategic raw material for a variety of products. One ...of the major challenges for developing rubber tree plantations is adapting the plant to biotic and abiotic stress. Transcriptome analysis is one of the main approaches for identifying the complete set of active genes in a cell or tissue for a specific developmental stage or physiological condition. Here, we report on the sequencing, assembling, annotation and screening for molecular markers from a pool of H. brasiliensis tissues. A total of 17,166 contigs were successfully annotated. Then, 2,191 Single Nucleotide Variation (SNV) and 1.397 Simple Sequence Repeat (SSR) loci were discriminated from the sequences. From 306 putative, mainly non-synonymous SNVs located in CDS sequences, 191 were checked for their ability to characterize 23 Hevea genotypes by an allele-specific amplification technology. For 172 (90%), the nucleotide variation at the predicted genomic location was confirmed, thus validating the different steps from sequencing to the in silico detection of the SNVs.
Effluent from the rubber industry contains 2-mercaptobenzothiazole (2-MBT) as the major persistent pollutant. To remove 2-MBT, this study investigated the bioaugmentation of activated sludge with a ...2-MBT-degrading bacterial consortium, which was previously enriched from rubber wastewater sludge. The consortium was immobilized in a commercial porous carrier to increase its efficiency and stability. The 16S rRNA gene analysis showed that the dominant Pseudomonas spp. and Stenotrophomonas spp. were maintained when it was repeatedly used for 4 cycles in a minimal medium containing 300 mg L−1 2-MBT. For bioaugmentation, a stirred tank reactor containing the immobilized consortium and activated sludge at a 1:2 mass ratio was constructed and found to remove 88.2 % of 100 mg L−1 2-MBT from synthetic wastewater. When the rubber industrial wastewater was applied at an organic loading rate (OLR) range of 1.0–3.0 kg COD m−3 d−1, the bioaugmentation reactor had 2-MBT and COD removal efficiencies of 70–79 % and 83–96 %, respectively. The reactors with either immobilized consortium or activated sludge alone had lower treatment efficiency. The bacterial community and its predicted functions corresponded to the activity of the added consortium and the operation of the reactor. Consequently, bioaugmentation should be applied to activated sludge for the treatment of rubber wastewater.
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•A bioaugmentation reactor contained bacterial consortium and activated sludge.•Bacterial immobilization in porous carriers allowed long-term reactor operation.•Immobilized bacteria and sludge removed around 80 % 2-MBT in rubber wastewater.•Major bacterial populations were identified along with their predicted functions.•Bacterial interactions and functions correlated with the efficiency of reactor.
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