Unraveling the Rheology of Nanocellulose Aqueous Suspensions:A Comprehensive Study on Biomass-Derived Nanofibrillated Cellulose

The rheological properties of nanocellulose aqueous suspensions play a critical role in the development of nanocellulose-based bulk materials.High-crystalline,high-aspect ratio,and slender nanofibrillated cellulose(NFC)were extracted from four biomass resources.The cellulose nanofibrils and nanofibril bundles formed inter-connected networks in the NFC aqueous suspensions.The storage moduli of the suspensions with different concentrations were higher than their corresponding loss moduli.As the concentration increased,the storage and loss modulus of NFC dispersion increased.When the shear rate increased to a certain value,there were differences in the changing trend of the rheological behavior of NFC aqueous suspensions derived from different biomass resources and the suspensions with different solid concentrations.NFC dispersion’s storage and loss modulus increased when the temperature rose to nearly 80℃.We hope this study can deepen the understanding of the rheological properties of NFC colloids derived from different biomass resources.

Overwhelming electrochemical oxygen reduction reaction of zinc-nitrogen-carbon from biomass resource chitosan via a facile carbon bath method

Developing high efficiency and low cost electrocatalysts is critical for the enhancement of oxygen reduction reaction(ORR),which is the fundamental for the development and commercialization of renewable energy conversion technology.Herein,zinc-nitrogen-carbon(Zn-N-C)was prepared by using biomass resource chitosan via a facile carbon bath method.The obtained Zn-N-C delivered a high specific surface area(794.7 cm^2/g)together with pore volume(0.49 cm^3/g).During the electrochemical evaluation of oxygen reduction reaction(ORR),Zn-N-C displayed high activity for ORR with an onset pote ntial E0=0.96 VRHE and a half wave potential E1/2=0.86 VRHE,which were more positive than those of the comme rcial 20 wt%Pt/C benchmark catalyst(E0=0.96 VRHE and E1/2=0.81 VRHE).In addition,the ZnN-C catalyst also had a better stability and methanol tolerance than those of the Pt/C catalyst.

Biomass-Derived Porous Carbon-Based Nanostructures for Microwave Absorption

Currently,electromagnetic(EM) pollution poses severe complication toward the operation of electronic devices and biological systems.To this end,it is pertinent to develop novel microwave absorbers through compositional and structural design.Porous carbon(PC)materials demonstrate great potential in EM wave absorption due to their ultralow density,large surface area,and excellent dielectric loss ability.However,the large-scale production of PC materials through low-cost and simple synthetic route is a challenge.Deriving PC materials through biomass sources is a sustainable,ubiquitous,and low-cost method,which comes with many desired features,such as hierarchical texture,periodic pattern,and some unique nanoarchitecture.Using the bio-inspired microstructure to manufacture PC materials in mild condition is desirable.In this review,we summarize the EM wave absorption application of biomass-derived PC materials from optimizing structureand designing composition.The corresponding synthetic mechanisms and development prospects are discussed as well.The perspective in this field is given at the end of the article.

A model to estimate available timber and forest biomass and reforestation expenses in a mountainous region in Japan

We developed a model to estimate supply potentials and available amounts of timber and forest biomass resources from profitable sub-compartments of thinning and final felling operations. Economic balances were estimated while considering not only harvesting expenses but also reforestation expenses after final felling, which should be considered for sustainable forest management. Harvesting expenses were estimated based on two types of timber harvesting systems and three types of forest biomass harvesting systems in each sub-compartment. Then, the model was applied to Nasushiobara city of Tochigi prefecture, Japan. Reforestation expenses had large negative impacts on the financial balances of final felling operations. Few sub-compartments were profitable after considering reforestation expenses. Most profitable sub-compartments were those with mechanized operation systems and landing sales. These accounted for 17.19% of all sub-compartments, while only 5.75% of the sub-compartments were profitable based on their current operation systems and landing sales. Although the overall supply potentials of timber and forest biomass resources were 380,000 m3 and 210,000 Mg, respectively, and 15 times the planned harvest of coniferous tree volume of 25,000 m3year-1 and 50 times the annual demand for the woody gasification power generation of 4,000 Mg year-1 in Nasushiobara, available amounts of timber and forest biomass resources were only49,429 m3 and 33,333 Mg, which were 13.0% and 15.7% of supply potentials for landing sales with mechanized operation systems.

Mg^(2+) improves biomass production from soybean wastewater using purple non-sulfur bacteria

Soybean wastewater was used to generate biomass resource by use of purple non-sulfur bacteria（PNSB）. This study investigated the enhancement of PNSB cell accumulation in wastewater by Mg2＋under the light-anaerobic condition. Results showed that with the optimal Mg2＋dosage of 10 mg/L, biomass production was improved by 70% to 3630 mg/L,and biomass yield also was improved by 60%. Chemical Oxygen Demand（COD） removal reached above 86% and hydraulic retention time was shortened from 96 to 72 hr. The mechanism analysis indicated that Mg2＋could promote the content of bacteriochlorophyll in photosynthesis because Mg2＋is the bacteriochlorophyll active center, and thus improved adenosine triphosphate（ATP） production. An increase of ATP production enhanced the conversion of organic matter in wastewater into PNSB cell materials（biomass yield） and COD removal, leading to more biomass production. With 10 mg/L Mg2＋, bacteriochlorophyll content and ATP production were improved by 60% and 33% respectively.

Integrated benefits of power generation by straw biomass--A case study on the Sheyang Straw Power Plants in Jiangsu Province,China

Power generation using straw biomass has quantifiable benefits from an economic,ecological,and sociological perspective in China.The methods used to construct the assessment models of these integrated benefits were the revenue capitalization approach and the discounted-cash-flow approach.The results indicated that a straw power plant with the capacity of 2.50×10^(7)W and burning 1.23×10^(5)tons of cotton straw could annually supply 1.40
×10^(8)kWh of power.However,it would not be until six years later that these results could be measured.Over the long term,the gross benefits could reach up to 4.63×10^(8)Yuan.Therefore,the total benefits are expected to be 1.18×10^(12)Yuan if all available straw resources are used to generate power.The policy implication showed that the long-term integrated benefits of power generation by straw biomass outweighed the short-term benefits.This is the main incentive to use straw biomass for power generation in the future.

A RESOURCE-DEPENDENT COMPETITION MODEL:EFFECTS OF POPULATION PRESSURE AUGMENTED INDUSTRIALIZATION

In this paper,a nonlinear mathematical model is proposed and analyzed to study the effects of population pressure augmented industrialization on the survival of competing species dependent on resource.It is assumed that the growths of competing species are logistic and carrying capacities increase with increase in the density of resource biomass.Further,it is assumed that the resource biomass too is growing logistically in the envi-ronment and its carrying capacity decreases with the increase in densities of competing species and industrialization.The growth rate of population pressure is assumed to be proportional to the densities of competing species.Stabilities of all equilibria and con-ditions which influence the permanence of the system are carried out using theory of differential equations.Numerical simulations are performed to accomplish our analytical findings.It is shown that the equilibrium density of resource biomass decreases as(i)the growth rate coefficient of population pressure increases(ii)the growth rate coeffi-cient of industrialization due to population pressure increases and(iii)the growth rate coefficient of industrialization due to resource biomass increases.It is found that the competitive outcome alters with increase in the growth rate coefficient of population pressure.Decrease in the equilibrium densities of competing species is also noted with increase in the growth rate coefficient of industrialization due to resource biomass.

Efficient oxygen reduction reaction by a highly porous,nitrogen-doped carbon sphere electrocatalyst through space confinement effect in nanopores

A highly porous nitrogen-doped carbon sphere(NPC)electrocatalyst was prepared through the carbonization of biomass carbon spheres mixed with urea and zinc chloride in N_(2) atmosphere.The sample carbonized at.1000℃ demonstrates a superior oxygen reduction reaction(ORR)performance over the Pt/C electrocatalyst,while its contents of pyridinic nitrogen and graphitic nitrogen are the lowest among samples synthesized at the same or lower carbonization temperatures.This unusual result is explained by a space confinement effect from the microporous and mesoporous structures in the microflakes,which induces the further reduction of peroxide ions or other oxygen species produced in the first step reduction to water to have the preferred overall four electron reduction ORR process.This work demonstrates that in addition to the amount or species of its aptive sites,the space confinement can be a new approach to enhance the ORR performance of precious-metal-free,nitrogen-doped carbon electrocatalysts.