Corrected Statistical Energy Analysis Model in a Non-Reverberant Acoustic Space

Statistical Energy Analysis (SEA) is a well-known method to analyze the flow of acoustic and vibration energy in a complex structure. This study investigates the application of the corrected SEA model in a non-reverberant acoustic space where the direct field component from the sound source dominates the total sound field rather than a diffuse field in a reverberant space which the classical SEA model assumption is based on. A corrected SEA model is proposed where the direct field component in the energy is removed and the power injected in the subsystem considers only the remaining power after the loss at first reflection. Measurement was conducted in a box divided into two rooms separated by a partition with an opening where the condition of reverberant and non-reverberant can conveniently be controlled. In the case of a non-reverberant space where acoustic material was installed inside the wall of the experimental box, the signals are corrected by eliminating the direct field component in the measured impulse response. Using the corrected SEA model, comparison of the coupling loss factor (CLF) and damping loss factor (DLF) with the theory shows good agreement.     

The coloring constituents of Scleroderma sinnamariense (Sclerodermaceae)

Two known coloring constituents, methyl 4,4'-dimethoxyvulpinate (1) and 4,4'-dimethoxyvulpinic acid (2) have been isolated from the fruit body of fungus Scleroderma sinnamariense Mont. The methanolic extract, its fractions and compound (2) showed moderate activity to inhibit the growth of some pathogenic testing microbes used.     

Sinulasulfoxide and sinulasulfone, sulfur-containing alkaloids from the Indonesian soft coral Sinularia sp.

Chemical analysis of the Indonesian soft coral Sinularia sp. (order Alcyonacea, family Alcyoniidae) afforded two new alkaloids, named sinulasulfoxide (1) and sinulasulfone (2), characterized by an amide linkage between a phytanic acid moiety and an uncommon sulfur-containing unit. Their complete stereostructures were elucidated by interpretation of MS and NMR data along with CD analysis and chemical modifications. Sinulasulfoxide (1) proved to moderately inhibit LPS-induced NO release.     

SMARTer for magnetic structure studies

SMARTer, a 36-meter small angle neutron scattering (SANS) spectrometer was installed at the Neutron Scattering Laboratory (NSL), National Nuclear Energy Agency of Indonesia — BATAN in Serpong, Indonesia and has performed the experiment for studying the magnetic structures of Cu(NiFe), CuCo and FeSiBNbCu metal alloys. The experiments were conducted at room temperature and up to 1 T (10 kOe) of external magnetic field. At zero fields, isotropic scattering identified as nuclear scattering is dominant. When a magnetic field is applied in a horizontal direction perpendicular to the neutron beam, the response of the magnetic scattering permits extraction of the field-induced re-arrangement of the magnetic moment. With increasing field the distortion is more pronounced and the magnetic scattering dominates the intensity and affects the peak position. Radial and angular averaging from experimental data are given to show the details of magnetic structures.      

<em>Cassia spectabilis </em>(DC) Irwin et Barn: A Promising Traditional Herb in Health Improvement

The genus Cassia, comprising about 600 species widely distributed worldwide is well known for its diverse biological and pharmacological properties. Cassia spectabilis (sin Senna spectabilis) (DC) Irwin et Barn (Fabaceae) is widely grown as an ornamental plant in tropical and subtropical areas. C. spectabilis has been commonly used in traditional medicine for many years. Information in the biomedical literature has indicated the presence of a variety of medicinally-important chemical constituents in C. spectabilis. Pharmacological studies by various groups of investigators have shown that C. spectabilis possesses significant biological activity, such as antibacterial, antibiofilm, antifungal and antioxidant properties. Beside this, toxicity studies of this plant have revealed no toxic effect on mice. In view of the immense medicinal importance of C. spectabilis, this review aimed at compiling all currently available information on C. spectabilis's botany, phytochemistry, pharmacology, and mechanism of actions, toxicology and its ethnomedicinal uses.     

The quaternary indole alkaloids from two Sumatran Lerchea species

The Sumatran forest plants Lerchea cf. bracteata and L. parviflora were found to contain alkaloids and their extract showed siginificant activity toward some testing pathogenic microbes. Isolation work on L.cf bracteata yielded known quaternary alkaloid N(b)-methylantirhine (2) while L. parviflora gave 5,6-dihydroflavopereirine (3).     

Copper‐Catalyzed Asymmetric Arylation of N‐Heteroaryl Aldimines: Elementary Step of a 1,4‐Insertion

Copper complexes of monodentate phosphoramidites efficiently promote asymmetric arylation of N‐azaaryl aldimines with arylboroxines. DFT calculations and experiments support an elementary step of 1,4‐insertion in the reaction pathway, a step in which an aryl‐copper species adds directly across four atoms of C=N?C=N in the N‐azaaryl aldimines.     

Realization of a low threshold multiwavelength brillouin/erbium fiber laser by optimizing the reflected power

A multiwavelength Brillouin/erbium fiber laser (BEFL) with low threshold power is realized. A low threshold power of 3 mW and a wide tuning range of 18 nm can be achieved by controlling the reflected power in the nonlinear optical loop mirror (NOLM). Up to 24 lines with a wavelength spacing of 0.086 nm are generated at the Brillouin pump and at the 1 480-nm pump with 0.5 dBm (0.9 mW) and 25 mW of power, respectively.