Simultaneous detection of the nonlinear restoring and excitation of a forced nonlinear oscillation: an integral approach

We address in this article, how to calculate the restoring characteristic and the excitation of a nonlinear forced oscillating system. Under the assumption that the forced nonlinear oscillator has a periodic solution with period, we constructed a system of linear equations by introducing time-dependent multipliers. The periodicity assumption helps simplify the system of linear equations. The stability and uniqueness are also presented for the inverse problem. Numerical testing is conducted to show the effectiveness of our presented methodology.Peer ReviewedPostprint (author's final draft

Potential Use of Gelidium amansii Acid Hydrolysate for Lactic Acid Production by Lactobacillus rhamnosus

Galactose and glucose are the main monosaccharides produced from the saccharification of Gelidium amansii. They were hydrolysed with 3 % (by volume) H2SO4 at 140 °C for 5 min and obtained at concentrations of 19.60 and 10.21 g/L, respectively. G. amansii hydrolysate (5 %, by mass per volume) was used as a substrate for L(+)-lactic acid production by Lactobacillus rhamnosus. The maximum lactic acid yield (YP/S) was 42.03 % with optical purity of 84.54 %. Lactic acid produced from G. amansii hydrolysate can be applicable, among others, for the production of lactic acid esters, like ethyl or methyl lactate, and disinfectant in seaweed cultivation

Production of L(+)-Lactic Acid from Mixed Acid and Alkali Hydrolysate of Brown Seaweed

The species of brown seaweeds, Laminaria japonica is commercially cultivated in Japan. Mannitol and uronic acid were the main component of mono sugar produced from the saccharification of L. japonica which hydrolysed with H2SO4 or NH4OH. The mannitol concentration of L. japonica (5w/v%) hydrolysate using 0.5v/v% H2SO4 or 1v/v% NH4OH were 15.84g/L and 13.87g/L, respectively. Hydrolysates from both acid and alkali hydrolysis were mixed together for neutralization as well as to obtain higher mannitol concentration of 15.18g/L. Among the mono sugar in the hydrolysate, Mannitol was the main substrate for the lactic acid fermentation by Lactobacillus rhamnosus. L(+)-Lactic acid with 97.9% of optical purity was successfully produced at the yield of 14.42g/L (Yp/s = 94.99%)

Application of Virtual and Augmented Reality to the Field of Adult Education

This research reviews the extant literature and web resources on Virtual Reality (VR) and Augmented Reality (AR) to provide new insights and future direction of adult learning. Based on the review, we discuss implications for research and practice on the use of VR and AR in the field of Adult Education

Production of mono sugar from acid hydrolysis of seaweed

The purpose of this work was to optimize the process conditions for the saccharification of macroalgae (seaweed) into mono sugar using the following parameters such as: Amount of biomass, catalyst concentration, temperature and reaction time. The major component of Ulva pertusa (green seaweed), Laminaria japonica (brown seaweed) and Gelidium amansii (red seaweed) is carbohydrate which can be converted into variety of sugars using sulfuric acid with hot-compress treatment. Rhamnose (37.89 wt %) and glucose (16.14 wt %) were extracted from dried U. pertusa, while galactose (49.32 wt %) and glucose (12.62 wt %) were extracted from dried G. amansii. Mannitol (31.53 wt %) was produced from dried L. japonica

Primjena kiselinskog hidrolizata alge Gelidium amansii u proizvodnji mliječne kiseline s pomoću bakterije Lactobacillus rhamnosus

Galactose and glucose are the main monosaccharides produced from the saccharification of Gelidium amansii. They were hydrolysed with 3 % (by volume) H2SO4 at 140 °C for 5 min and obtained at concentrations of 19.60 and 10.21 g/L, respectively. G. amansii hydrolysate (5 %, by mass per volume) was used as a substrate for L(+)-lactic acid production by Lactobacillus rhamnosus. The maximum lactic acid yield (YP/S) was 42.03 % with optical purity of 84.54 %. Lactic acid produced from G. amansii hydrolysate can be applicable, among others, for the production of lactic acid esters, like ethyl or methyl lactate, and disinfectant in seaweed cultivation.Galaktoza i glukoza su glavni monosaharidi koji nastaju saharifikacijom alge Gelidium amansii. Kiselinskom hidrolizom algi pomoću 3 %-tne otopine H2SO4 pri 140 °C tijekom 5 min dobiveno je 19,60 g/L galaktoze i 10,21 g/L glukoze. Hidrolizat alge Gelidium amansii (5 % m/V) upotrijebljen je kao podloga za proizvodnju L(+)-mliječne kiseline s pomoću bakterije Lactobacillus rhamnosus. Najveći prinos (YP/S) mliječne kiseline, optičke čistoće od 84,54 %, bio je 42,03 %. Mliječna kiselina dobivena iz hidrolizata alge Gelidium amansii može se primijeniti za proizvodnju estera mliječne kiseline, kao što su etilni ili metilni laktat, ili kao dezinficijens pri uzgoju morskih trava

To the Edge of M87 and Beyond: Spectroscopy of Intracluster Globular Clusters and Ultra Compact Dwarfs in the Virgo Cluster

We present the results from a wide-field spectroscopic survey of globular clusters (GCs) in the Virgo Cluster. We obtain spectra for 201 GCs and 55 ultracompact dwarfs (UCDs) using the Hectospec on the Multiple Mirror Telescope, and derive their radial velocities. We identify 46 genuine intracluster GCs (IGCs), not associated with any Virgo galaxies, using the 3D GMM test on the spatial and radial velocity distribution.They are located at the projected distance 200 kpc $\lesssim$ R $\lesssim$ 500 kpc from the center of M87. The radial velocity distribution of these IGCs shows two peaks, one at $v_{\rm r}$ = 1023 km s$^{-1}$ associated with the Virgo main body, and another at $v_{\rm r}$ = 36 km s$^{-1}$ associated with the infalling structure. The velocity dispersion of the IGCs in the Virgo main body is $\sigma_{\rm{GC}} \sim$ 314 km s$^{-1}$, which is smoothly connected to the velocity dispersion profile of M87 GCs, but much lower than that of dwarf galaxies in the same survey field, $\sigma_{\rm{dwarf}} \sim$ 608 km s$^{-1}$. The UCDs are more centrally concentrated on massive galaxies, M87, M86, and M84. The radial velocity dispersion of the UCD system is much smaller than that of dwarf galaxies. Our results confirm the large-scale distribution of Virgo IGCs indicated by previous photometric surveys. The color distribution of the confirmed IGCs shows a bimodality similar to that of M87 GCs. This indicates that most IGCs are stripped off from dwarf galaxies and some from massive galaxies in the Virgo.Comment: 19 pages, 20 figures, 8 tables, accepted for publication in Ap

Insulin Secretion and Incretin Hormone Concentration in Women with Previous Gestational Diabetes Mellitus

BackgroundWe examined the change in the levels of incretin hormone and effects of glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide 1 (GLP-1) on insulin secretion in women with previous gestational diabetes (pGDM).MethodsA 75-g oral glucose tolerance test (OGTT) was conducted on 34 women with pGDM. In addition, 11 women with normal glucose tolerance, matched for age, height and weight, were also tested. The insulin, GIP, GLP-1, and glucagon concentrations were measured, and their anthropometric and biochemical markers were also measured.ResultsAmong 34 women with pGDM, 18 had normal glucose tolerance, 13 had impaired glucose tolerance (IGT) and 1 had diabetes. No significant differences were found in GLP-1 concentration between the pGDM and control group. However, a significantly high level of glucagon was present in the pGDM group at 30 minutes into the OGTT. The GIP concentration was elevated at 30 minutes and 60 minutes in the pGDM group. With the exception of the 30-minute timepoint, women with IGT had significantly high blood glucose from 0 to 120 minutes. However, there was no significant difference in insulin or GLP-1 concentration. The GIP level was significantly high from 0 to 90 minutes in patients diagnosed with IGT.ConclusionGLP-1 secretion does not differ between pGDM patients and normal women. GIP was elevated, but that does not seem to induce in increase in insulin secretion. Therefore, we conclude that other factors such as heredity and environment play important roles in the development of type 2 diabetes