Dielectric constant of glasses: first observation of a two-dimensional behavior

The 1kHz real part $\chi'$ of the dielectric constant of a structural glass was measured at low temperature $T$ down to 14 mK. Reducing the sample thickness $h$ to 10 nm suppresses the usual minimum of $\chi'$ for measuring fields $E<.5$ MV/m. This contradicts the Two Level System (TLS) model but is well accounted for by including TLS-TLS interactions where excitations delocalize between TLS's through a $E$-induced mechanism recently designed: for small $h$'s this interaction is reduced, which explains the two-dimensional behavior of $\chi'(T)$. Hence, interactions play a key role in standard thick samples.Comment: latex finesse3.tex, 5 files, 4 figures, 4 pages [SPEC-S02/050], submitted to Phys. Rev. Let

Struktur Dan Komponen Arang Serta Arang Aktif Tempurung Kemiri

Cara aktivasi arang menentukan kekhususan penggunaan arang aktif yang dihasilkan. Secara umum dikenal dua cara aktivasi arang untuk menghasilkan arang aktif yaitu cara fisika dan kimia. Penelitian ini bertujuan untuk mengetahui struktur dan komponen penyusun arang dan arang aktif tempurung kemiri. Tempurung kemiri dikarbonisasi menggunakan tungku drum untuk menghasilkan arang, selanjutnya arang diaktivasi di dalam retort listrik menggunakan aktivator panas selama 120 menit pada suhu 550C, 650C, dan 750C dan aktivator uap air selama 90 dan 120 menit pada suhu 750C. Sampel uji tempurung kemiri, arang dan arang aktif dikarakterisasi strukturnya yang meliputi gugus fungsi, kristalinitas dan porositas dengan menggunakan Fourier Transform Infra Red (FTIR), X-Ray Difractometer (XRD) dan Scanning Electron Microscope (SEM). Selain itu, senyawa kimia masing-masing sampel uji diidentifikasi menggunakan Pyrolisis Gas Chromatograph Mass Spectrometer (Py-GCMS) Hasil mengindikasikan bahwa proses aktivasi menyebabkan terjadinya Perubahan pola gugus fungsi, peningkatan kristalinitas, pembukaan pori dan reduksi senyawa kimia. Semakin tinggi suhu aktivasi diikuti oleh peningkatan kristalinitas, diameter pori dan reduksi senyawa kimia arang aktif. Aktivasi menggunakan uap air menghasilkan arang aktif dengan pori yang relatif lebih bersih

Karakterisasi Permukaan Arang Aktif Tempurung Biji Nyamplung

Characterization&nbsp; of&nbsp; Surface&nbsp; Active&nbsp; Shell&nbsp; Charcoal&nbsp; Nyamplung&nbsp; Seeds (Calophyllum&nbsp; inophyllum&nbsp; Linn). Chemical and physical activation of nyamplung shell with 0%, 5%, and 10% H3PO4 for 60 and 120 minutes has been carried out to&nbsp; prepare&nbsp; activated&nbsp; charcoal.&nbsp; The&nbsp; purpose&nbsp; of this&nbsp; experiment&nbsp; was&nbsp; to&nbsp; look&nbsp; into&nbsp; the&nbsp; characteristic&nbsp; of&nbsp; nyamplung shell activated&nbsp; charcoal&nbsp; surface.&nbsp; Nyamplung&nbsp; shell&nbsp; was&nbsp; carbonized&nbsp; into charcoal,&nbsp; then&nbsp; activated&nbsp; by&nbsp; immersion&nbsp; in&nbsp; H3PO4 solution&nbsp; using&nbsp; 0%, 5%&nbsp; and&nbsp; 10%,&nbsp; for&nbsp; 24&nbsp; hours,&nbsp; and&nbsp; heated&nbsp; in&nbsp; retort at&nbsp; two temperatures&nbsp; (700 and 800 oC) and two duration (60 and 120 minutes). The material were characterized by&nbsp; fourier transform infra red (FTIR), scaning electron microscope (SEM) and X-ray diffraction (XRD). The FTIR spectrum show that&nbsp; activated charcoal has OH, C-H, C-O and&nbsp; C=C bonds. The&nbsp; bonds&nbsp; of&nbsp; OH&nbsp; and&nbsp; C-O&nbsp; indicated&nbsp; that&nbsp; the&nbsp; treatment&nbsp; was produced&nbsp; polar&nbsp; activated&nbsp; charcoal. The porous&nbsp; texture&nbsp; was&nbsp; influenced by&nbsp; H3PO4&nbsp; concentration.&nbsp; The&nbsp; porous&nbsp; with&nbsp; dimension&nbsp; &lt;5 &mu; being predominant at low concentration of H3PO4 (0% and 5%) but larger amount of H3PO4 (10%) produced wide pore with dimension &gt;5 &mu;. &nbsp

Kajian Struktur Arang dari Lignin

Tulisan ini membahas struktur arang dari lignin pada suhu karbonisasi yang berbeda. Proses pembuatan arang lignin dilakukan pada suhu 200, 300, 400, 500, 650, 750 dan 850°C dalam suatu retort yang terbuat dari baja tahan karat yang dilengkapi dengan pemanas listrik Untuk mengetahui Perubahan struktur arang yang terjadi dilakukan analisis dengan menggunakan FTIR, XRD dan SEM. Hasil analisis XRD menunjukkan bahwa jarak antar ruang lapisan aromatik (d) dan lebar lapisan aromatik (La) menurun dengan makin meningkatnya suhu karbonisasi, sedangkan untuk tinggi lapisan aromatik (Lc), derajat kristalinitas (X) dan jumlah lapisan aromatik (N) meningkat dengan makin naiknya suhu karbonisasi. Spektrum FTIR dari arang lignin menunjukkan bahwa antara suhu 300-500°C terjadi Perubahan struktur kimia dari bahan baku secara nyata. Ikatan OH, dan C=C alifatik menurun dengan naiknya suhu, sedangkan struktur eter dan aromatik makin berkembang. Pada suhu 850°C arang yang dihasilkan mempunyai struktur aromatik yang permukaannya mempunyai gugus C-O-C, C=O dan C- H. Analisis SEM menunjukkan bahwa jumlah dan diameter pori arang meningkat dengan makin naiknya suhu karbonisasi. Kualitas arang yang baik diperoleh pada suhu karbonisasi 500°C yang menghasilkan derajat kristalinitas sebesar 33,90 %, tinggi lapisan aromatik 3.21 nm, lebar lapisan aromatik 10,96 nm, jumlah lapisan aromatik 8,67, jarak antar lapisan aromatik d(002) = 0,35 nm dan d(100) = 0,21 nm dengan diameter pori arang antara 12,6 mm. Arang ini mempunyai sifat keteraturan yang tertinggi, permukaannya bersifat polar, kaku, keras dan struktur porinya makropor

Positive allosteric modulation of GABAB receptors ameliorates sensorimotor gating in rodent models

This is the peer reviewed version of the following article: Frau, R., Bini, V., Pillolla, G., Malherbe, P., Pardu, A., Thomas, A. W., Devoto, P. and Bortolato, M. (2014), Positive Allosteric Modulation of GABAB Receptors Ameliorates Sensorimotor Gating in Rodent Models. CNS Neurosci Ther, 20: 679–684. doi:10.1111/cns.12261, which has been published in final form at http://doi.org/10.1111/cns.12261. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.BACKGROUND: Converging evidence points to the involvement of γ-amino-butyric acid B receptors (GABABRs) in the regulation of information processing. We previously showed that GABABR agonists exhibit antipsychotic-like properties in rodent models of sensorimotor gating deficits, as measured by the prepulse inhibition (PPI) of the acoustic startle reflex. The therapeutic potential of these agents, however, is limited by their neuromuscular side effects; thus, in the present study we analyzed whether rac-BHFF, a potent GABABR positive allosteric modulator (PAM), could counter spontaneous and pharmacologically induced PPI deficits across various rodent models. METHODS: We tested the antipsychotic effects of rac-BHFF on the PPI deficits caused by the N-methyl-D-aspartate glutamate receptor antagonist dizocilpine, in Sprague-Dawley rats and C57BL/6 mice. Furthermore, we verified whether rac-BHFF ameliorated the spontaneous PPI impairments in DBA/2J mice. RESULTS: rac-BHFF dose-dependently countered the PPI deficits across all three models, in a fashion akin to the GABABR agonist baclofen and the atypical antipsychotic clozapine; in contrast with these compounds, however, rac-BHFF did not affect startle magnitude. CONCLUSIONS: The present data further support the implication of GABABRs in the modulation of sensorimotor gating, and point to their PAMs as a novel promising tool for antipsychotic treatment, with fewer side effects than GABABR agonists

Antihyperlipidemic and antiperoxidative effect of Diasulin, a polyherbal formulation in alloxan induced hyperglycemic rats

BACKGROUND: This study was undertaken to investigation the effect of Diasulin, a poly herbal drug composed of ethanolic extract of ten medicinal plants on blood glucose, plasma insulin, tissue lipid profile, and lipidperoxidation in alloxan induced diabetes. METHODS: Ethanolic extract of Diasulin a, poly herbal drug was administered orally (200 mg/kg body weight) for 30 days. The different doses of Diasulin on blood glucose and plasma insulin in diabetic rats were studied and the levels of lipid peroxides [TBARS, and Hydroperoxide] and tissue lipids [cholesterol, triglyceride, phospholipides and free fatty acids] were also estimated in alloxan induced diabetic rats. The effects were compared with glibenclamide. RESULT: Treatment with Diasulin and glibenclamide resulted in a significant reduction of blood glucose and increase in plasma insulin. Diasulin also resulted in a significant decrease in tissue lipids and lipid peroxide formation. The effect produced by Diasulin was comparable with that of glibenclamide. CONCLUSION: The decreased lipid peroxides and tissue lipids clearly showed the antihyperlipidemic and antiperoxidative effect of Diasulin apart from its antidiabetic effect

Half-metallic antiferromagnets in double perovskites: LaAVRuO6_6 (A=Ca, Sr, and Ba)

Based on the theoretical exploration of electronic structures, we propose that the ordered double perovskites LaAVRuO$_6$ and LaVO$_3$/ARuO$_3$ (001) superlattice (A = Ca, Sr and Ba) are strong candidates for half-metallic (HM) antiferromagnets (AFMs). %LaAVRuO$_6$ and LaVO$_3$/ARuO$_3$ have the %100% spin polarizations at the Fermi level but with zero %total magnetic moments. We have shown that the HM-AFM nature in LaAVRuO$_6$ is very robust regardless of (i) divalent ion replacement at A-sites, (ii) oxygen site relaxation, (iii) the inclusion of the Coulomb correlation, and (iv) cation disorder. A type of the double exchange interaction is expected to be responsible for the half-metallicity and the antiferromagnetism in these systems.Comment: 4 pages, 4 figure

Flavor symmetry breaking effects on SU(3) Skyrmion

We study the massive SU(3) Skyrmion model to investigate the flavor symmetry breaking (FSB) effects on the static properties of the strange baryons in the framework of the rigid rotator quantization scheme combined with the improved Dirac quantization one. Both the chiral symmetry breaking pion mass and FSB kinetic terms are shown to improve $c$ the ratio of the strange-light to light-light interaction strengths and $\bar{c}$ that of the strange-strange to light-light.Comment: 12 pages, latex, no figure

The Meteorite Fall in Carancas, Lake Titicaca Region, Southern Peru: First Results

The meteorite fall that occurred on September 15, 2007, in the Carancas community is a rare case where it is possible to study both impact phenomenology and meteorite characteristics, including accurate time framework

KARAKTERISASI ASAP CAIR HASIL PIROLISIS SAMPAH ORGANIK PADAT (CHARACTERIZATION OF LIQUID SMOKE PYROLYZED FROM SOLID ORGANIC WASTE)

AbstractThe liquid smoke had been produced from raw material of solid organic waste using pyrolysis reactor. The composition of organic waste as 30% bamboo, 30% wood, 20% small branch and 20% fruit peel was separated and coped manually, and then put into pyrolysis reactor. Pyrolysing processing at 350-510 oC for 5 hours and liquid smoke produced was characterized by means of rendement, total phenol and pH parameter. Besides that, the liquid smoke component was identified by GCMS. The result of this research showed that the liquid smoke was generally brownish-red color, with rendement 22.87-34.67 %, pH 3.8-4.8, and total phenolic 6.15x10-3-2.24x10-2 %. Increasing pyrolysis temperature up to 505 oC tended to increase total phenolic compound. GCMS analysis on the liquid smoke identified 61 compound, i.e. ketone (17 compounds), phenolic (14 compounds), carboxylic acid (8 compounds), alcohols (7 compounds), ester (4 compounds), aldehyde (3 compounds), and other 1 compounds. Keywords: liquid smoke, solid organic waste, pyrolysis, qualit