Bio-Based Polyisoprene Can Mitigate Climate Change and Deforestation in Expanding Rubber Production

Biomass is a promising renewable feedstock to produce polyisoprene for the rubber industry. Through metabolic engineering, sugars derived from pretreated and hydrolyzed cellulose and hemicellulose can be directly fermented to isoprene to produce rubber. Here we investigate the life cycle environmental impact of isoprene fermentation to produce bio-polyisoprene from agricultural residues (of Zea mays L.). Results show that the greenhouse gas (GHG) intensity of bio-polyisoprene (−4.59 kg CO2e kg−1) is significantly lower than that of natural rubber (Hevea brasiliensis) and synthetic rubber (−0.79 and 2.41 kg CO2e kg−1, respectively), while supporting a circular biogenic carbon economy. We found the land use intensity of bio-polyisoprene to be 0.25 ha metric ton−1, which is 84% lower than that from rubber tree plantations. We compare the direct fermentation to isoprene results with indirect fermentation to isoprene through the intermediate, methyl butyl ether, where dehydration to isoprene is required. The direct fermentation of isoprene reduces reaction steps and unit operations, an expected outcome when employing process intensification, but our results show additional energy conservation and reduced contribution to climate change. Among the ReCiPe life cycle environmental impact metrics evaluated, air emission related impacts are high for bio-polyisoprene compared to those for natural and synthetic rubber. Those impacts can be reduced with air emission controls during production. All other metrics showed an improvement for bio-polyisoprene compared to natural and synthetic rubber

<span style="font-size: 22.0pt;mso-bidi-font-size:15.0pt;font-family:"Times New Roman","serif"; mso-bidi-font-weight:bold">Laser Raman spectroscopic studies of order-disorder phase transitions in Na_{<span style="font-size:17.0pt;mso-bidi-font-size: 10.0pt;font-family:"Times New Roman","serif";mso-bidi-font-weight:bold">3</span>}<span style="font-size:22.0pt;mso-bidi-font-size:15.0pt;font-family:"Times New Roman","serif"; mso-bidi-font-weight:bold">BaCl_{<span style="font-size:17.0pt; mso-bidi-font-size:10.0pt;font-family:"Times New Roman","serif";mso-bidi-font-weight: bold">5</span>}<span style="font-size:22.0pt;mso-bidi-font-size:15.0pt; font-family:"Times New Roman","serif";mso-bidi-font-weight:bold">.2H₂O crystals </span></span></span>

650-653<span style="font-size: 15.5pt;mso-bidi-font-size:8.5pt;font-family:" times="" new="" roman","serif""="">Laser Raman spectroscopic studies have been undenaken for Na<span style="font-size:17.0pt; mso-bidi-font-size:10.0pt;font-family:" times="" new="" roman","serif";mso-bidi-font-weight:="" bold"="">3<span style="font-size:22.0pt;mso-bidi-font-size:15.0pt; font-family:" times="" new="" roman","serif";mso-bidi-font-weight:bold"="">BaCl5<span style="font-size:22.0pt; mso-bidi-font-size:15.0pt;font-family:" times="" new="" roman","serif";mso-bidi-font-weight:="" bold"="">.2H2O<span style="font-size:15.5pt;mso-bidi-font-size: 8.5pt;font-family:" times="" new="" roman","serif""=""> single crystals to study the structural phase transitions taking place in them through spectra- structure correlation. The spectral changes that take place in the low temperature phase below 267 K in this crystal in terms of intensity and bandwidth or the streching and librational modes show that these are indications or diffuse phase transitions associated with an order-disorder mechanism which involves the rotation or water molecules, freezing  below 267 K. No evidence of soft modes has been found for the crystal in the temperature region of<span style="font-size:13.5pt;mso-bidi-font-size:6.5pt; font-family:" arial","sans-serif""=""> t<span style="font-size:15.5pt; mso-bidi-font-size:8.5pt;font-family:" times="" new="" roman","serif""="">he presence studies. </span

Effect of Ce3+ Ion on the X-Ray Induced Fluorescence Emission from CaS

The effect of Ce3+ on the fluorescence emission from CaS:Ce3+ phosphor is studied using X-ray excitation. Apart from the emission in the visible region, the phosphor also shows fluorescence emission in the ultraviolet region. Variation in wavelengths and intensities of these emissions due to change in dopant concentration is also analysed