Judul: Pengaruh pengukusan terhadap retensi dan penetrasi diffusol cb pada kayu durian (Durio zibethinus Murr.)
Abstrak: Salah satu jenis kayu yang penggunaannya akhir-akhir ini tergolong meningkat khususnya di Kabupaten Bogor adalah kayu durian (Durio zibethinus Murr.). Namun demikian kayu ini memiliki keawetan alami yang rendah dan keterawetan yang sukar sehingga perlu dilakukan perlakuan pendahuluan sebelum diawetkan. Pada penelitian ini dilakukan perlakuan pengukusan sebagai perlakuan awal dengan tujuan untuk meningkatkan permeabilitas sehingga penetrasi dan retensi bahan pengawet menjadi lebih baik. Bahan-bahan yang digunakan terdiri dari kayu durian (Durio zibethinus Murr.), Diffusol CB, ammonia pekat, air suling, asam rubianat, alkohol, aseton, serbuk kunyit, asam klorida pekat, dan asam salisilat. Faktor perlakuan yakni bagian batang (ujung, tengah, pangkal) sebagai blok, waktu pengukusan (0- 30-, 60-, 90 menit), dan konsentrasi bahan pengawet (3-, 4- dan 5%). Pengujian meliputi penghitungan retensi dan penetrasi bahan pengawet. Hasil penelitian menunjukkan bahwa retensi dipengaruhi secara nyata oleh bagian batang, waktu pengukusan dan konsentrasi bahan pengawet yang diterapkan. Interaksi antara waktu pengukusan dan konsentrasi bahan pengawet tidak mempengaruhi nilai retensi secara nyata. Rata-rata nilai retensi berkisar antara 1,17 hingga 5,21 kg/m3. Penetrasi senyawa boron dipengaruhi oleh bagian batang dan konsentrasi bahan pengawet. Waktu pengukusan serta interaksi antara waktu pengukusan dan konsentrasi bahan pengawet tidak mempengaruhinya secara nyata. Rata-rata nilai penetrasi berkisar antara 3,61 hingga 12,58 mm. Penetrasi senyawa tembaga sangat dangkal sehingga dapat diabaikan. Retensi optimum terdapat pada bagian tengah batang yang dikukus selama 30 menit dan diawetkan dengan bahan pengawet berkonsentrasi 3%, sedangkan penetrasi optimum terdapat pada bagian pangkal dengan konsentrasi bahan pengawet dan waktu pengukusan yang sama.
Keyword: Kayu durian (Durio zibethinus Murr.), Pengukusan, Retensi, Penetrasi, Bogor Agricultural University

Judul: Pengaruh Konsentrasi Bahan Pengawet Boron terhadap Retensi dan Penetrasi pada Kayu Rakyat
Abstrak: INTRODUCTION. Nowadays, wood supply from natural forest continues to decrease. It resulted in the development of community forest in many areas in Indonesia. In general, community forest has been developing using fast-growing species. The wood obtained is generally inferior compared to that from the natural forest, particularly in term of natural durability and strength. Therefore, it is necessary to improve the quality of such kind of woods. The aims of the research were to determine the natural durability of wood species from community forest and to evaluate effect of boron concentration onto retention and penetration of these species. Wood natural durability was evaluated after exposing the samples in the field for 3 months following the procedure of American Standard for Testing and Material (ASTM) D 1756 2008. MATERIALS AND METHOD. The main materials used were the wood of durian (Durio zibethinus), karet (Hevea brasiliensis), manii (Maesopsis eminii) and petai (Parkia speciosa) from small business unit of sawmill in Cinangneng, Bogor. The others are boron with three concentrations (5%, 10% and 15%) as the preservative, and curcuma extract, alcohol, chloric acid (HCl), aquades and salicylic acid as dying solution. Preservation process applied was cold bath method for 2 hours. Retention and penetration were used as the indicator. Data was then analyzed using experimental design factorial randomly by two factors (wood species and boron concentration) with three replications. RESULT AND DISCUSSIONS. The result showed that natural durability of all wood species studied was low. It belongs to Durability Class of IV and V. This indicates that all wood species need to be enhanced through the preservation. Based on this study it showed that petai wood has the highest value of the retention (4.31 kg/m3), while durian wood was the lowest (2.37 kg/m3). Retention value of karet wood, known is rubberwood, was almost similar to that of manii wood. Result also showed that penetration value of all wood species studied were almost similar namely 50.13% (durian), 51.55% (karet), 51.57% (petai) and 52.78% (manii). The results indicate that retention value was influenced by wood species, boron concentration and the interaction of these two factors, while penetration value was only affected by the concentration. Factors of wood species which affect the retention are related to the anatomical structure, as well as the existence and the amount of free hydroxyl group (-OH-) that are present in the cell wall components. In general, retention and penetration values tend to increase with the increasing of boron concentration. In all wood species studied, the concentration of 15% resulted in the highest of retention and the deepest of penetration.
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Judul: Pengembangan Sistem Rotasi Peta pada Perangkat Mobile tanpa Sensor Magnetometer
Abstrak: Due to the improvement of technology, the function of mobile phone has changed a lot. Nowadays, mobile phone is used not only for communication, but also to support the user’s activity. Many mobile phones now have Operating System (OS) and sensors like GPS and magnetometer. GPS is a sensor that can be used to identify any location, including the location of the user, while magnetometer can be used to identify direction. With data that come from GPS and magnetometer, we can build a navigation application that can rotate its map according to the rotation of the user. Meanwhile, in the Android Compability Definition Document point 1.6 until 2.2, Google have requirements for mobile phones to have GPS and magnetometer sensors if they want to use Android OS. But, since the release of 2.3.3 OS, Google has changed its requirements, allowing any mobile phones to have Android OS without having the magnetometer sensor. The objective of this research is to build an navigation application that can rotate without using magnetometer sensor. The value of the rotation degree is taken from last two position. To stabilize the value, Exponential Smoothing is used in filtering process. This system also use Haversine method to recognize whether the user is walking or driving/riding.
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