23 research outputs found
Production of bacterial cellulose from alternative low-cost substrates
Cellulose is the most widely used biopolymer on Earth. Its large-scale production is mainly from lignocellulosic material (plant origin), however, this plant material is not the only source of this valuable polymer, since microorganisms, like bacteria, naturally produce cellulose, especially those of the genus Komagateibacter (formerly Gluconacetobacter). This type of cellulose is of great interest because of its unique properties such as high purity and resistance, nevertheless, it has not been produced in a large-scale industrial process to date using low-cost substrates, one of the key aspects that should be considered for the industrial obtaining of any biotechnological product. As a main finding we found that the majority of low-cost culture media discussed could have the potential to produce bacterial cellulose on an industrial scale, since in most cases they yield more cellulose (with similar physical chemical characteristics) to those obtained in standard media. However, for an appropriate large-scale production, a specific knowledge about these by-products (since their composition and characteristics, which have a direct impact on the productivity of this biopolymer, are quite heterogeneous) and a proper standardization of them would also be required. Research staff of many industries could use the information presented here to help design a process to use their respective byproducts as substrate to obtain a product with a high added value as bacterial cellulose
Study of the decay D0→K¯0π−e+νe
We report a study of the decay D0→K̄0π-e+νe based on a sample of 2.93 fb-1 e+e- annihilation data collected at the center-of-mass energy of 3.773 GeV with the BESIII detector at the BEPCII collider. The total branching fraction is determined to be B(D0→K̄0π-e+νe)=(1.434±0.029(stat.)±0.032(syst.))%, which is the most precise to date. According to a detailed analysis of the involved dynamics, we find this decay is dominated with the K∗(892)- contribution and present an improved measurement of its branching fraction to be B(D0→K∗(892)-e+νe)=(2.033±0.046(stat.)±0.047(syst.))%. We further access their hadronic form-factor ratios for the first time as rV=V(0)/A1(0)=1.46±0.07(stat.)±0.02(syst.) and r2=A2(0)/A1(0)=0.67±0.06(stat.)±0.01(syst.). In addition, we observe a significant K̄0π- S-wave component accounting for (5.51±0.97(stat.)±0.62(syst.))% of the total decay rate
Study of the decay D0→K¯0π−e+νe
We report a study of the decay D0→K̄0π-e+νe based on a sample of 2.93 fb-1 e+e- annihilation data collected at the center-of-mass energy of 3.773 GeV with the BESIII detector at the BEPCII collider. The total branching fraction is determined to be B(D0→K̄0π-e+νe)=(1.434±0.029(stat.)±0.032(syst.))%, which is the most precise to date. According to a detailed analysis of the involved dynamics, we find this decay is dominated with the K∗(892)- contribution and present an improved measurement of its branching fraction to be B(D0→K∗(892)-e+νe)=(2.033±0.046(stat.)±0.047(syst.))%. We further access their hadronic form-factor ratios for the first time as rV=V(0)/A1(0)=1.46±0.07(stat.)±0.02(syst.) and r2=A2(0)/A1(0)=0.67±0.06(stat.)±0.01(syst.). In addition, we observe a significant K̄0π- S-wave component accounting for (5.51±0.97(stat.)±0.62(syst.))% of the total decay rate
Study of the h(c)(1(1)P(1)) meson via psi(2S) -> pi(0)h(c) decays at BESIII
Using 448 million psi(2S) events, the spin-singlet P-wave charmonium state h(c)(1(1)P(1)) is studied via the psi(2S) -> pi(0)h(c) decay followed by the h(c) -> gamma eta(c) transition. The branching fractions are measured to be B-Inc(psi(2S) -> pi(0)h(c)) x B-Tag (h(c) -> gamma eta(c)) = (4.22(-0.26)(+0.27) +/- 0.19) x 10(-4), B-Inc (psi(2S) -> pi(0)h(c)) = (7.32 +/- 0.34 +/- 0.41) x 10(-4) , and B-Tag (h(c) -> gamma eta(c)) = (57.66(-3.50)(+3.62) +/- 0.58)%, where the uncertainties are statistical and systematic, respectively. The h(c)(1(1)P(1)) mass and width are determined to be M = (3525.32 +/- 0.06 +/- 0.15) MeV/c(2) and Gamma = (0.78(-0.24)(+0.27)+/- 0.12) MeV. Using the center of gravity mass of the three chi(cJ) (1(3)P(J)) mesons [M(c.o.g.)], the 1P hyperfine mass splitting is estimated to be Delta(hyp) = M(h(c)) - M(c.o.g.) = (0.03 +/- 0.06 +/- 0.15) MeV/c(2), which is consistent with the expectation that the 1P hyperfine splitting is zero at the lowest order