Neraca Karbon, Emisi dan Serapan Historis Co2 Karena Perubahan Penggunaan Lahan di Kabupaten Banyuasin, Sumatera Selatan

Land use change is the cause of carbon loss from land. The loss of this carbon becomes a source of carbon dioxide (CO2) in the atmosphere that can cause global warming. Intensive land use and land cover occurred in Kabupaten Banyuasin from 2004-2014. The purpose of this study. to create carbon balance, emissions and sequestration of CO2 during the period of 2004 - 2014 in Banyuasin Regency caused by land use change and land cover change. The method used to create carbon balance using land use change matrix, carbon calculation of each carbon pool by allometric method, destructive sample and organic C by Walkley and Black method. Stock diference method for analysis of changes in carbon storage, CO2 emissions and CO2 sequestration. The results of this study indicate that the 2004-2014 carbon balance in Banyuasin Regency is negative, with a carbon loss of 22,033,277 tons with an average annual carbon loss of 2,203,327 tons. CO2 sequestration of 29,298,966 tons and CO2 emissions 118,044,141 tons, while net emissions 88,745,175 tons. Average net CO2 emissions from above ground carbon pools, carbon necromassa pools, litter carbon pools and underground carbon pools are 7 tonnes ha-1 year-1, whereas CO2 emissions from organic soil C 0.61 tonnes ha- 1 year-1. The largest contributor of CO2 emissions in Banyuasin Regency are sequentially caused by changes in peat swamp forests, secondary mangrove forests, primary mangrove forests and secondary swamp forests. While the source of sequestration is the change of monoculture rubber peat, oil palm, rubber monoculture and shrubs

Analisis Surface Roughness dan Material Removal Rate pada Proses Sinker-edm Menggunakan Elektroda Graphite

Electrical discharge machining (EDM) is a non-conventional machining process by feeding the workpiece material by means of an electric spark (spark) through the gap between the electrode and the workpiece containing a dielectric fluid. The EDM process is influenced by the material being processed, electrode material, discharge current, spark on time, spark gap, dielectric fluid and so on. The combination of these parameters will produce different machining characteristics. The purpose of this study was to determine the value of the material removal rate and surface roughness of the workpiece (Surface Roughnes), using graphite electrodes and using the Taguchi method to determine the optimal parameters by varying the current parameters 10A, 13A. , 16A, spark on time 210µ, 340µ, 400µ and gap 40, 45, 50

Transcatheter Closure of Perimembranous Ventricular Septal Defect Using the Lifetech Konar-Multi Functional Occluder: Early to Midterm Results of the Indonesian Multicenter Study

Background: The alternative device to close perimembranous ventricular septal defect (pmVSD) has been searched for better result, less complications and applicable for infants. However, the ideal device is still unavailable. We aimed to evaluate the effectiveness and outcome of transcatheter pmVSD closure using the KONAR-multi functional occluder (MFO). Methods: Clinical, procedural, follow-up data of pmVSD patients with symptom of heart failure or evidence of significant left to right shunt, growth failure, recurrent respiratory tract infection, and history of endocarditis who underwent transcatheter closure using the MFO were prospectively evaluated. Results: Between January 2016 and December 2017, there were complete records of 132 pmVSD children closed using MFO from eleven centers in Indonesia. The median of age was 4.5 (0.3-17.4) years; weight 14.8 (3.5-57) kg, defect size at the smallest part 3.4 (1.0-8.1) mm, flow ratio 1.6 (1.3-4.9), mean pulmonary artery pressure 18 (7-79) mmHg, fluoroscopy time 18 (3.8-91) and procedural time 75 (26-290) minutes. A retrograde approach was done in 41 (31%) patients. Procedures succeeded in first attempt in 126 (95.4%), failed in three and migration in three patients. Six of eight infants with congestive heart failure were closed successfully. Of 126 patients with successful VSD closure, 12 months follow-up were completed in all patients. The rate of complete occlusion at 1 month, 3 months, 6 months and 12 months after intervention were 95.2%, 97.6%, 99.2%, and 99.2%, respectively. New-onset aortic regurgitation and moderate tricuspid regurgitation developed only in five and three patients. Neither complete atrioventricular block, nor other complications occurred. Conclusion: Transcatheter closure of pmVSD using the MFO is safe, effective, and feasible in infants and children