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"Telah dilakukan suatu modifikasi pada sistem laser nitrogen untuk meningkatkan efisiensi pemakaian gas nitrogen dan daya keluaran laser. Modifikasi dilakukan pada bentuk elektrode dan konstruksi celah laser, sedemikian sehingga gas nitrogen yang dipakai sedikit (efisien) tapi daya keluaran tinggi. Sebagai pembanding digunakan konstruksi sistem laser nitrogen (sistem lama). Laser nitrogen yang dibuat (sistem baru) dapat dioperasikan pada daerah tegangan 7,48 kV sampai 10,30 kV. Sedangkan laser nitrogen (sistem lama) dapat dioperasikan pada daerah tegangan 6,96 kV sampai 11 kV. Optimalisasi dilakukan pada jarak antar elektroda celah laser 1,98 mm, tegangan keluaran penyedia daya 9,17 kV, debit aliran gas 7,3 liter/jam dan menggunakan cermin datar pada salah satu ujung keluaran laser. Diperoleh bahwa sistem laser (sistem baru) menghasilkan daya keluaran laser maksimal 3,3 mW. Sedangkan sistem laser (sistem lama) menghasilkan daya keluaran laser maksimal 0,6 mW. Kondisi optimum tegangan keluaran peyedia daya diperoleh pada tegangan 8,64 kV (sistem baru) dan pada tegangan 9,54 kV (sistem lama)."

"ABSTRACT

Probing of the atmospheric parameters have been done by many scientists since a century ago up to present with various techniques. A simple system of laser radar without using any collimated beam but a reflected mirror as transmitter and a small cassegranian type (10.5 an in diameter) telescope as receiving was constructed to investigate the relative Mie backscattering coefficient by utilizing a nitrogen laser as a light source in the range of measurement bellow 1 Km. The backscattered light received by the receiving telescope is converted into electric current by photomultiplier and is shown and known as "A scope" display on an oscilloscope. SNR of the signal from photomultiplier was increased by using a boxcar integrator and its output could be recorded with XY recorder."

"Characterizations have been performed on single stage Transversely Excited Nitrogen Laser of Blumlein type. Optical cavity arrangement is varied prior to measurement which shows no significant increase in energy on both configurations of inserting a mirror only and a pair of mirror and a quartz parallel plate. Frequency repetitions respond reveals a small drop in energy at higher frequency i.e. 10 Hz by a factor of 20%. N2 flow rate consideration behaves on the similar way like pressure profile. At higher supply voltage maximum energy is shifted to higher N2 flow rate. A similar tendency occurs on pressure curve but with more pronounced maximum energy. Higher supply voltage would shift maximum energy to higher N2 pressure. Other operating conditions have been kept constant. Beam divergence measurement has given 1,87 mrad on vertical direction and 9,32 mrad on horizontal axis. However, beam cross section experiences a -10° tilt against horizontal reference. This may happen due to a slight twist on main electrodes. Measurements on different date have showed inconsistent results. Major cause is suspected on using different N2 cylinder, replacement on the gauge pressure, and crater creation on HV side spark gap electrode."

"ABSTRACTThe autofluorescence spectra of human tissues excited with 33'7,1-nm line of pulse nitrogen laser have been measured. The autofluorescence spectra of cancerous tissues consistently exhibit characteristic peaks near E530-nm and 690-nm. which do not appear in the spectra of the corresponding normal tissues. Spectroscopic investigation indicates that the porphyrin compounds localized and retained in cancerous tissues might be responsible for this characteristic autofluorescence. This preliminary result suggests the possibility of employing spectroscopy tool for complementary diagnosis of cancer along with the traditional methods of pathological analysis."

"ABSTRACTLaser induced thin film production (LITFP) technique was employed for making plumbum (Pb) thin film by nitrogen laser deposition in miniature scale. The energy of nitrogen laser operated at 12.5 kv, 90 torr was 3.5 mj with 5 ns pulse duration, thus producing peak power at around 0.7 MW. Pb plasma of 1 cm diameter was generated in each laser bombardment, producing thin film above the glass substrate. The thin film characteristics were measured by means of their thickness and surface morphology using scanning electron microscope (SEM). It was proved that there was a linear relationship between the number of laser shots and film thickness."

"Nitrogen Expander merupakan jenis pencairan gas bumi yang sering diaplikasikan dalam kilang produksi LNG karena beberapa karakteristiknya. Namun, masalah utama dalam pengaplikasian teknologi ini adalah efisiensi energi yang relatif rendah. Dalam penelitian ini, kegiatan optimisasi pencairan gas bumi skala kecil berjenis expander telah dilakukan dengan cara menambahkan sistem precooling