Pengaruh Metode Pengeringan Terhadap Kualitas Simplisia Lempuyang Wangi (Zingiber Aromaticum L.)

Pengeringan merupakan tahapan terpenting dalam menjaga kestabilan senyawa pada simplisia. Simplisia tanaman lempuyang wangi sejak lama dikenal sebagai bahan ramuan obat untuk diare, disentri penyakit kulit dan antimikroba. dikenal sebagai bahan ramuan obat untuk diare, disentri penyakit kulit dan antimikroba. Penelitian ini dilaksanakan di Balai Besar Penelitian dan Pengembangan Tanaman dan Obat (B2P2TO2T). Penelitian ini bertujuan untuk mengetahui pengaruh metode pengeringan terhadap biomasa, kadar air, rendemen minyak atsiri dan nilai kesukaan terhadap simplisia tanaman lempuyang wangi. Metode pengeringan yang digunakan adalah pengeringan dengan oven 50oC, pengeringan sinar matahari langsung dan kering angin. Parameter yang diamati yaitu biomasa, kadar air, rendemen minyak atsiri dan nilai kesukaan. Hasilnya menunjukkan pengeringan menggunakan oven suhu 50oC merupakan pengeringan yang paling baik dengan kadar air paling sedikit 8.4%, rendemen minyak atsiri paling banyak 0.87 % meskipun biomasa paling sedikit yakni 239,36 g

Cascade Boltzmann - Langevin approach to higher-order current correlations in diffusive metal contacts

The Boltzmann - Langevin approach is extended to calculations of third and fourth cumulants of current in diffusive-metal contacts. These cumulants result from indirect correlations between current fluctuations, which may be considered as "noise of noise". The calculated third cumulant coincides exactly with its quantum-mechanical value. The fourth cumulant tends to its quantum-mechanical value $-e^3I/105$ at high voltages and to a positive value $2e^2T/3R$ at V=0 changing its sign at $eV \sim 20T$.Comment: 6 pages, 2 eps figures, typo corrected, minor change

“What you don't know can't hurt you”: The right to know and the Shetland Island oil spill

This paper, an account of the Shetland Islands oil spill (1993), examines the public health controversies surrounding the spill and the clean- up response. It critically examines the risk management policies of both the United Kingdom and the Shetland Islands Public Health Office, and suggests that the withholding of critical information contributed to increased anxiety and suspicion among the disaster victims. In an attempt to reassure the victims, the policies contributed to an increased air of uncertainty. It is further argued that the withholding of information prevents those who are at greatest risk from participating in critical decisions that may affect their health and livelihoods and asserts that a right- to- know policy is a critical first step in risk management practices .Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44488/1/10745_2005_Article_BF01191651.pd

Exploring the Bimodal Solar System via Sample Return from the Main Asteroid Belt: The Case for Revisiting Ceres

Abstract: Sample return from a main-belt asteroid has not yet been attempted, but appears technologically feasible. While the cost implications are significant, the scientific case for such a mission appears overwhelming. As suggested by the “Grand Tack” model, the structure of the main belt was likely forged during the earliest stages of Solar System evolution in response to migration of the giant planets. Returning samples from the main belt has the potential to test such planet migration models and the related geochemical and isotopic concept of a bimodal Solar System. Isotopic studies demonstrate distinct compositional differences between samples believed to be derived from the outer Solar System (CC or carbonaceous chondrite group) and those that are thought to be derived from the inner Solar System (NC or non-carbonaceous group). These two groups are separated on relevant isotopic variation diagrams by a clear compositional gap. The interface between these two regions appears to be broadly coincident with the present location of the asteroid belt, which contains material derived from both groups. The Hayabusa mission to near-Earth asteroid (NEA) (25143) Itokawa has shown what can be learned from a sample-return mission to an asteroid, even with a very small amount of sample. One scenario for main-belt sample return involves a spacecraft launching a projectile that strikes an object and flying through the debris cloud, which would potentially allow multiple bodies to be sampled if a number of projectiles are used on different asteroids. Another scenario is the more traditional method of landing on an asteroid to obtain the sample. A significant range of main-belt asteroids are available as targets for a sample-return mission and such a mission would represent a first step in mineralogically and isotopically mapping the asteroid belt. We argue that a sample-return mission to the asteroid belt does not necessarily have to return material from both the NC and CC groups to viably test the bimodal Solar System paradigm, as material from the NC group is already abundantly available for study. Instead, there is overwhelming evidence that we have a very incomplete suite of CC-related samples. Based on our analysis, we advocate a dedicated sample-return mission to the dwarf planet (1) Ceres as the best means of further exploring inherent Solar System variation. Ceres is an ice-rich world that may be a displaced trans-Neptunian object. We almost certainly do not have any meteorites that closely resemble material that would be brought back from Ceres. The rich heritage of data acquired by the Dawn mission makes a sample-return mission from Ceres logistically feasible at a realistic cost. No other potential main-belt target is capable of providing as much insight into the early Solar System as Ceres. Such a mission should be given the highest priority by the international scientific community

Along-arc variations in the pre-eruptive H2O contents of mariana arc magmas inferred from fractionation paths

New experimental results are presented on the effects of dissolved H2O during low-pressure (\u3c 2 kbar) crystal fractionation in Mariana Arc magmas. The resulting fractionation paths are used to infer the pre-eruptive H2O concentrations of Mariana lavas from seamounts and islands. Estimated pre-eruptive H2O concentrations for Mariana seamounts (2-3 wt %) are relatively constant and similar to three out of eight of the subaerial volcanoes (Alamagan, Pagan and Asuncion). These H2O concentrations are also similar to measured H2O concentrations in Mariana back-arc lavas. Lavas from the remaining islands (Guguan, Agrigan, Uracas, Anatahan and possibly Sarigan) have significantly higher H2O (5-6%) than the other seamounts and islands. These high-H2O islands are distributed throughout the arc and do not show any relation to variations in subduction parameters such as subduction angle or obliquity. Analysis of the H2O concentrations of olivine-hosted melt inclusions from seven islands (Guguan, Pagan, Agrigan, Anatahan, Alamagan, Asuncion and Sarigan) and one seamount (Fukujin) match the estimates inferred from the liquid lines of descent. One interpretation of our results is that the flux of volatiles from the Mariana sub-arc mantle is fundamentally heterogeneous. Alternatively, the variations in pre-eruptive H2O concentrations could reflect variations in the depth and extent of fractionation of Mariana magmas. © The Author 2010. Published by Oxford University Press. All rights reserved