Synthesis of Biokerosene Through Electrochemical Hydrogenation of Terpene Hydrocarbons From Turpentine Oil

Indonesia possesses great potential for developing renewable resources as alternative fuels. For example, turpentine oil obtained from Pinus merkusii, which contains mostly monoterpene hydrocarbons (C10H16). The oil is highly suitable to be processed for biokerosene or even jet biofuel. It consists of hydrocarbons within the range of C10 to C15. However, it contains insufficient H and thus needs to be upgraded. In the present work, electrochemical hydrogenation was used for upgrading. In the electrochemical cell, stainless steel, silver, and carbon were used alternately for the anode, while copper and silver Raschig rings were used for the cathode. An electrolyte solution of cuprous ammonium formate was utilized not only as a source of H but also to draw the unsaturated hydrocarbons into the aqueous phase. The electrolyte : oil ratio (up to 2:1), electrolyte concentration (between 0.4 and 2 M) and reaction time were varied throughout the experiments. The bromine number (unsaturation level) of the turpentine oil, which was initially 1,86 (mole Br2/mole), was lowered significantly to 0.69-0.90. Promising increase of smoke point values were observed from 11 mm to 16-24 mm, indicating a higher H content of the processed oil, thus making it suitable as a substitute for petroleum kerosene

Manajemen Laba dan Konsekuensi Ekonomis (suatu Pendekatan Eksperimen)

Earnings management can be seen as a discretion allowed by generally accepted Standards, but it also has a less positive impact if earnings that contain certain objectives of the manager (management) become the basis in economic decision making. However, earnings management does not have to be associated with efforts to manipulate accounting data or information, but tends to be associated with choosing accounting methods to manage earnings that can be done because it is permitted by accounting standards. This study is focused on looking at the two sides of earnings management by using an experimental approach and the economic consequences caused by the chosen perspective. The results of data processing indicate that participants' perceptions of ethical and unethical behavior towards earnings management practices are the same as the economic consequences for the organization

DINAMIKA ORBIT ASTEROID YANG ANALOG DENGAN ORBIT BUMI

A set of asteroids that belong to Atens and Apollos groups which orbits are crossing the Earth at 1 AU is known as Earth-like-Orbit Asteroids. As of 1 July 2009, there were 19 Earth-like-Orbit Asteroids listed at the JPL (Jet Propulsion Laboratory – NASA) Small-Body Database. Orbital dynamics of five new asteroids among them (2008 EV5, 2008 JE, 2008 KT, 2008 UA202, and 2008 UC202) have not been studied yet. This study is important because they are asteroids belonging to potentially hazardous objects. High accuracy orbital integrations for a time-span of –1000 to +1000 yr have been conducted to figure out their evolutionary tracks. Our results show that high inclination Earth-like-Orbit Asteroids of more than ~5 degrees tend to be more dynamically stable than those of lower orbital inclination which often switch over from Atens to Apollos and vice versa. Four new Earth-like-Orbit Asteroids are found to have potential collisions with Earth because they will encounter the Earth at minimum distances of less than 0.01 AU. Keywords: Asteroids, Orbit dynamics, Hazardous object

EVOLUSI ORBIT CENTAURS DAN TRANS-NEPTUNUS KE BAGIAN DALAM TATA SURYA

Dynamical study of Trans-Neptunian Objects (TNOs) showed that the orbital evolution of TNOs, especially for Scattered-Disk class, is closely related to Centaurs. As of 1 June 2009, there were 673 known Centaurs and TNOs whose orbits are well-determined within an uncertainty of 6.4 /decade. It is interesting to investigate a fraction of evolving Centaurs and TNOs to inner solar system regions along 1 Myr evolution under perturbations of all planets. In order to have a better knowledge about spatial distributions of Centaurs and TNOs, we generated additional four sets artificial data based on the known distribution. We find that most Centaurs show chaotic orbital evolutions and many of them are ejected out to the outer solar system. The ejected Centaurs in the first-half evolution are more numerous than that of the second-half one. This study also indicates that number of Centaurs originated from 3:2 Neptune resonance objects is more abundant at about 5 105 yr, and only ~1% Centaurs and TNOs evolve to be Mars-crossers. Keywords: Asteroids, Orbit dynamic, Centaurs, Trans-Neptunu

EVOLUSI ORBIT CENTAURS DAN TRANS-NEPTUNUS KE BAGIAN DALAM TATA SURYA

Dynamical study of Trans-Neptunian Objects (TNOs) showed that the orbital evolution of TNOs, especially for Scattered-Disk class, is closely related to Centaurs. As of 1 June 2009, there were 673 known Centaurs and TNOs whose orbits are well-determined within an uncertainty of ? 6.4 ?/decade. It is interesting to investigate a fraction of evolving Centaurs and TNOs to inner solar system regions along 1 Myr evolution under perturbations of all planets. In order to have a better knowledge about spatial distributions of Centaurs and TNOs, we generated additional four sets artificial data based on the known distribution. We find that most Centaurs show chaotic orbital evolutions and many of them are ejected out to the outer solar system. The ejected Centaurs in the first-half evolution are more numerous than that of the second-half one. This study also indicates that number of Centaurs originated from 3:2 Neptune resonance objects is more abundant at about 5 ? 105 yr, and only ~1% Centaurs and TNOs evolve to be Mars-crossersTelaah dinamika objek Trans-Neptunus menunjukkan bahwa evolusi orbitnya, khususnya kelas Scatter-Disk, berkaitan erat dengan Centaurs. Sampai 1 Juni 2009 terdapat 673 objek Centaurs dan Trans-Neptunus yang orbitnya diketahui dengan sangat baik dengan ketidakpastian 6.4'/dekade. Adalah menarik untuk mencari tahu fraksi jumlah objek Centaurs dan Trans-Neptunus yang berevolusi ke bagian dalam tata surya sepanjang 1 juta tahun, dengan melibatkan gangguan seluruh planet. Agar sebaran lokasi objek Centaurs dan Trans-Neptunus dapat dipahami dengan baik, kami membangun empat set data artifisial berdasarkan sebaran orbital yang telah diketahui. Pekerjaan ini menunjukkan bahwa banyak Centaurs memperlihatkan evolusi orbit yang chaotic dan banyak di antaranya terlempar ke tepian tata surya. Objek Centaurs yang terlempar pada paruh pertama evolusi jauh lebih banyak daripada paruh keduanya. Studi ini juga mengindikasikan bahwa Centaurs yang berasal dari objek resonansi 3:2 Neptunus mencapai jumlah yang banyak pada sekitar 5 x 105 tahun, dan hanya -1% Centaurs dan Trans-Neptunus berevolusi menjadi Mars-Grassers.hal.102-11