Hydrothermal Carbonization of Deciduous Biomass(Alnus incana)and Pelletization Prospects

Thermal treatment of biomass has been attracting attention for a decade or so, especially torrefaction. However, for the past few years, wet pyrolysis, also known as hydrothermal carbonization (HTC), has been getting some attention. Hydrothermal carbonization is a thermal treatment of biomass in the presence of water in a temperature range of 180°C - 260°C. This method of treating biomass has some benefits which others do not, such as it can handle extremely wet biomass. However, treating biomass may not be enough for practical use. It may need to be transported and stored. Thus, this study explored the idea of pelletizing the HTC biomass. The mechanical strength of the HTC pellets was found to be 93%, whereas, higher heating value (HHV) (dry basis) was found to be 4% higher than the corresponding white pellets. The initial results with some limited parameters indicated that it would be possible to pelletize without binder. However, extensive research on energy balance and economic assessment would be necessary to achieve economic feasibility.

Mid-infrared dual-comb spectroscopy with electro-optic modulators

Absorption spectroscopy of fundamental ro-vibrational transitions in the mid-infrared region provides a powerful tool for studying the structure and dynamics of molecules in the gas phase and for sensitive and quantitative gas sensing.Laser frequency combs permit novel approaches to perform broadband molecular spectroscopy.Multiplex dual-comb spectroscopy without moving parts can achieve particularly high speed,sensitivity and resolution.However,achieving Doppler-limited resolution in the mid-infrared still requires overcoming instrumental challenges.Here we demonstrate a new approach based on difference-frequency generation of frequency-agile near-infrared frequency combs that are produced using electro-optic modulators.The combs have a remarkably flat intensity distribution,and their positions and line spacings can be freely selected by simply dialing a knob.Using the proposed technique,we record,in the 3-μm region,Doppler-limited absorption spectra with resolved comb lines within milliseconds,and precise molecular line parameters are retrieved.Our technique holds promise for fast and sensitive time-resolved studies of,for example,trace gases.

Parity violation in chiral structure creation under femtosecond laser irradiation in silica glass?

The paper addresses the creation of circular optical properties from a femtosecond laser light beam with a linear polarization in an achiral material(glass)under an orthogonal incidence.In this situation,all aspects of the experiment are achiral and therefore should not give rise to chiral property creation.From that observation,we propose an interpretation that involves the action of a light-induced torque on the matter carrying a light-induced dielectric moment.We found that a direct current(DC)electric field could be produced in the lattice by the femtosecond laser in our conditions and that a non-collinear dielectric moment is created by a nonlinear effect between the DC electric field and the stress field due to the transformation of the material.We reveal that it is possible to break the chiral symmetry of glass using an intense,ultrashort laser light pulse.

Nanoparticles with high payloads of pipemidic acid, a poorly soluble crystalline drug: drug-initiated polymerization and self-assembly approach

Nowadays, biodegradable polymers such as poly(lactic acid)(PLA), poly(D,L-lactic-coglycolic acid)(PLGA) and poly(ε-caprolactone)(PCL) remain the most common biomaterials to produce drug-loaded nanoparticles(NPs). Pipemidic acid(PIP) is a poorly soluble antibiotic with a strong tendency to crystallize. PIP incorporation in PLA/PLGA NPs was challenging because of PIP crystals formation and burst release. As PIP had a poor affinity for the NPs, an alternative approach to encapsulation was used, consisting in coupling PIP to PCL. Thus, a PCL–PIP conjugate was successfully synthesized by an original drug-initiated polymerization in a single step without the need of catalyst.PCL–PIP was characterized by NMR, IR, SEC and mass spectrometry. PCL–PIP was used to prepare selfassembled NPs with PIP contents as high as 27%(w/w). The NPs were characterized by microscopy,DLS, NTA and TRPS. This study paves the way towards the production of NPs with high antibiotic payloads by drug-initiated polymerization. Further studies will deal with the synthesis of novel polymer–PIP conjugates with ester bonds between the drug and PCL. PIP can be considered as a model drug and the strategy developed here could be extended to other challenging antibiotics or anticancer drugs and employed to efficiently incorporate them in NPs.