Judul: Tingkat emisi CH4 dan N2O serta produktivitas tanaman jarak pagar (Jatropha curcas L.) pada tiga sumber pupuk nitrogen.
Abstrak: Metana (CH4) dan dinitro oksida (N2O) adalah adalah gas penting di atmosfer yang mempengaruhi kekuatan radiasi dan sifat kimia atmosfer. Pertanian adalah salah satu kegiatan manusia yang menjadi sumber emisi CH4 dan N2O. Tanaman jarak pagar (Jatropha curcas L.) adalah salah satu jenis tanaman yang dapat digunakan sebagai sumber minyak nabati. Peenggunaan pupuk nitrogen telah diketahui mampu meningkatkan pertumbuhan tanaman termasuk diantaranya tanaman jarak pagar. Acuan rekomendasi pemupukan telah diketahui. Namun, bagaimana perannya dalam menghasilkan emisi gas rumah kaca belum diketahui. Pengaturan pemupukan yang baik diharapkan dapat mereduksi emisi gas rumah kaca dan meningkatkan serapan karbon tanaman. Bertolak dari hal tersebut, penelitian ini bertujuan untuk mengetahui pengaruh pemberian pupuk nitrogen terhadap emisi CH4 dan N2O dan pertumbuhan tanaman jarak pagar.
Keyword: 

Judul: Emisi gas CH4 dan serapan karbon dari aplikasi pupuk anorganik, organik dan tanaman sela pada budidaya jarak pagar
Abstrak: Production of Jatropha as a biofuel can be increased by fertilization. Subtitution chemical fertilizer into organic fertilizer have to consider the methane (CH4) emissions from soil that fertilizer applied. In this study the rate of methane (CH4) emission from jatropha cake compost (-0.99 CH4/m2/hour) and peanuts intercrops (- 0.62 CH4/m2/hour) is lower than urea fertilizer (- 0.04 CH4/m2/hour). Carbon sequestration is a reference to see the potential of the plant to reduce the CO2 in the atmosphere. Application of urea fertlizer showed carbon uptake (13.62 tonnes C/ha/year) higher than between fertilizer application (12.83 ton C/ha/year) and jatropha cake compost (11.09 tonnes C/ha/year). The productivity of jatropha from the jatropha cake compost (152 kg/ha/year) and intercrops (147.1 kg/ha/year) application was higher than urea fertilizer (147 kg/ha /year).
Keyword: 

Judul: Algorithm construction of HLI hash function
Abstrak: Cryptography is a study of mathematical techniques related to aspects of information security regarding on confidentiality, data integrity, entity authentication, and data origin authentication. Data integrity is a service, which is associated with the conversion of data carried out by unauthorized parties. To maintain data integrity, one can use hash functions. An hash function is a computationally efficient function to map an arbitrary length bitstring to a fixed length bitstring called as hash value. The use of hash function in maintaining the information integrity and authentication is in digital signatures, virus protection, and software distribution. Illustration of the hash function in the integrity and authentication of information that is emailed as follow. The sender sends the information and hash value to the recipient. If the hash value of the information is equal to the hash value that is sent by the sender, then information has not been changed. Otherwise the information has been changed. An hash function has two properties, one way and collision resistance. An hash function is called one way if it is computationally infeasible to find any input such that when given any hash value . Meanwhile an hash function is called collision resistant if it is computationally infeasible to find any two inputs where such that . The purpose of this study is to construct a HLI hash function algorithm, to analyze the speed and security of the hash functions as a results of construction. Furthermore, it is to compare it with SWIFFT. Hash function is constructed based on the result of algebraic operations on modular polynomial ringwith . Modular polynomial ring noted as is a set of all polynomials of degree at most with coefficients in . can be represented as a set of integer vector of modulo in dimension . So, it is simple to implement in a computer. In vector operations, is lattice . Furthermore, alattice that is defined from certain polynomial ring is called ideal lattice. HLI hash function is consists of addition and multiplication algorithm in the ring. Addition algorithm consists of sumation operations of modulo and multiplication consists of multiplication operations of modulo . Generally, algorithm of HLI hash function consists of multiplication operations of modulo and addition operations of modulo . However, if the input is binary number then multiplication algorithm only consists of multiplication operation of modulo , so algorithm of HLI hash function consists of multiplication operations of modulo and addtion operations of modulo . An hash function is secured if it has two properties, i.e., one way and collision resistance. HLI hash function hash is one way, it is following the proof of Micciancio. It is has collision resistant because of polynomial is irreducible over and monic. Moreover, it is proved that for every unit vector , the vector is small vector. If the input of hash function is a binary number then HLI hash function only involves addition operations of modulo . So the time that used almost same with SWIFFT. The excellence of HLI hash function is the key size smaller than SWIFFT. This effect on
Keyword: hash function, modular polynomial ring, lattice