Implementasi Algoritma Advanced Encryption Standard (AES) 128 Untuk Enkripsi dan Dekripsi File Dokumen

Keamanan data atau informasi adalah hal yang sangat penting bagi pengguna jaringan internet saat ini. Kasus penyadapan akan pesan atau informasi merupakan salah satu hal yang sangat merugikan, dengan adanya kemungkinan terjadinya kejadian ini, maka perlunya peningkatan dalam hal keamanan pertukaran informasi menjadi penting. Pada saat ini, keamanan pertukaran informasi ini perlu mendapatkan perhatian khusus, maka penelitian ini akan membuat suatu implementasi kriptografi algoritma AES-128 untuk enkripsi dan dekripsi data yang berupa file dokumen (PDF, DOC, TXT). Algoritma Advanced Encryption Standard (AES) dipilih karena memiliki suatu tingkat keamanan pertukaran informasi yang cukup bagus, dan pada penelitian ini diuji coba file dokumen untuk melihat kecepatan waktu yang dibutuhkan selama proses enkripsi dan dekripsi

Development of an exhaust air turbine engine

The article discusses ways of utilizing exhaust gas heat to improve the power efficiency of heat engines. The concept of an air turbine engine is chosen to make a generator drive with the capacity of 150 kW intended to produce energy for a gas-pumping unit. In an air turbine engine atmospheric air heated by the exhaust gases of the gas turbine drive of a gas pumping unit serves as the working fluid. Three thermodynamic cycle schematics for an air turbine engine (ATE) are analyzed. The optimal design of an ATE comprising a two-stage axial compressor, a recuperative air heater (RAH), an ejector and a single-stage axial turbine is determined on the basis of thermodynamic calculations. Compressed air from the ATE compressor unit is used in the ejector as the active flow, while the combustion products of the NK-16ST engine are used as the passive flow. The recuperative air heater and ejector are located in the exhaust line of the gas pumping unit. The chosen design concept of the air turbine engine corresponds to the technical requirements of gas transmission enterprises

La Patrie : journal quotidien, politique, commercial et littéraire

18 octobre 18511851/10/18 (A11,N291)

RATIO OF SURGICAL CORRECTION SPINAL CANAL WITH INJURIES AND DEGENERATIVE SPINE DISEASES

Ratio of surgical correction spinal canal during injury and illness was suggested. At SCT and MRI in the sagittal projection of the measured diameter of the cross-section of the spinal canal at the site of maximum narrowing (d2), in the overlying (d1) and underlying (d3) levels, we calculated the coefficient of stenosis (Kst): Kst = 1 – 2d22: (d12 + d32). After surgery, surgical correction factor was determined (KK): KK = 1 – Kst2: Kst1, where Kst1 – coefficient of stenosis before surgery, Kst2 – after the operation. Surgical correction was considered unsatisfactory by KK < 0,4

New technologies implemented in the design of a low-emission combustion chamber of a gas-turbine unit

Metallist-Samara JSC has developed a fundamentally new design of a unified double-circuit burner of a low-emission combustion chamber (LECC) of a ground-based gas turbine unit (GTU), adapted for manufacturing with the help of an innovative technology by selective laser melting (SLM) of metal powders using CAD models. Several batches of burners were made and control studies were carried out characterizing the quality of manufacturing according to the established procedure. Deficiencies inherent in the SLM process were discovered, the main of which are: raised roughness, in particular, of the fuel channels of the main and duty zones; microporosity, microalloying; microcracks; instability of flow characteristics; local non-sintering zones of the layers grown on the burner body. As a result of the analysis of the state of the manufactured burners, research and refinements, it was found that most of the identified shortcomings can be eliminated during further development of the modes and parameters of the technological process. Currently, difficult engineering problems associated with the implementation of additive manufacturing technologies have been overcome

Genetic identification of bovine leukaemia virus

Molecular genetic research methods make it possible to evaluate the genetic diversity of bovine leukemia virus (BLV) and are the most informative approaches to its genetic identification. Molecular genetic research methods work well for the phylogenetic analysis of sequenced nucleotide DNA sequences of the provirus, as well as for the polymerase chain reaction-restriction fragment length polymorphism analysis (PCR-RFLP) according to the phylogenetic classification of the pathogen. The purpose of the research was to study the scientific and methodological approaches to the genetic identification of bovine leukemia virus, integrated into the molecular monitoring of infection of cattle with BLV genotypes. The authors used PCR-RFLP-genotyping and comparative phylogenetic analysis of aligned nucleotide sequences of the env gene fragment of the BLV provirus isolates to detect the genotypic affiliation of the cattle from twenty-one livestock farms of the Republic of Tatarstan. As a result, isolates of four out of ten BLV genotypes were found in the Tatarstani cattle, namely genotypes 1, 4, 7, and 8. The research involved a comparative analysis of 505 nucleotide sequences of a fragment of the BLV env gene, including those deposited in GenBank NCBI. The analysis confirms the inconsistency of several earlier PCR-RFLP typing strategies with the current approach in assessing the genotypic diversity by phylogenetic analysis. The improved strategy of PCR-RFLP genotyping of BLV corresponds with its modern phylogenetic classification. The strategy makes it possible to identify all the known genotypes of the viral pathogen. Its validity has been proved by in silico modelling of restrictogrammes and a phylogenetic analysis of the env gene fragment of 57 reference isolates of ten BLV genotypes that generate 57 genotype-associated combinations of diagnostically significant PCR-RFLP profiles