Pengaruh Feri Klorida terhadap Kedalaman Pengikisan dan Kekasaran Permukaan Aluminium Murni

Penelitian chemical machining mengenai pengaruh larutan feri klorida (FeCl3) terhadap kedalaman pengikisan dan kekasaran permukaan aluminium murni perdagangan telah dilakukan. Aluminium direndam dengan FeCl3 dengan variasi konsentrasi 5% (b/v), 8% (b/v) dan 11% (b/v). Masing-masing variasi konsentrasi FeCl3 dilakukan untuk variasi waktu perendaman 2 jam, 4 jam dan 6 jam. XRF menganalisis aluminium murni menunjukkan adanya unsur lain berupa Zn, Cr, Ti, V dan Cu. Fe3+ dalam FeCl3 mengoksidasi Al sebagai komponen utama material menyebabkan pengikisan. Perbedaan potensial reduksi standar unsur-unsur penyusun material aluminium menyebabkan kekasaran permukaan bila direndam dalam FeCl3. Pengikisan aluminium cenderung semakin dalam dengan bertambah besarnya konsentrasi FeCl3 dan bertambahnya waktu perendaman. Permukaan aluminium cenderung semakin kasar dengan bertambah besarnya konsentrasi FeCl3 dan bertambahnya waktu perendaman. Waktu perendaman 2 jam dalam konsentrasi FeCl3 5% (b/v) hingga 11% (b/v) menghasilkan kedalaman pengikisan antara 0,02 mm hingga 0,06 mm. Sedangkan waktu perendaman 6 jam dalam konsentrasi FeCl3 5% (b/v) hingga 11% (b/v) menghasilkan kedalaman pengikisan antara 0,09 mm hingga 0,19 mm. Waktu perendaman 2 jam dalam konsentrasi FeCl3 5% (b/v) hingga 11% (b/v) menghasilkan kekasaran permukaan antara 0,35 μm hingga 0,91 μm. Sedangkan waktu perendaman 6 jam dalam konsentrasi FeCl3 5% (b/v) hingga 11% (b/v) menghasilkan kekasaran permukaan antara 3,30 μm hingga 5,09 μm

Evaluasi Kesesuaian Lahan Kabupaten Dairi Untuk Tanaman Kopi Robusta (Coffea Robusta Lindl.)

This research purposed to evaluate the suitability of land for cultivation of robusta coffee in Dairiwith altitude at 400 - 1700 m above sea level . This research started from May 2013 to November2013. The research conducted by taking a sample soil based by method free survey grid with detailof survey level and then analyzed on the laboratory and land evaluation performed by the matchingmethod is based on plants needed with properties owned by land on any limiting factors. Theparameters observed in the field are soil depth, drainage, slope, the dangers of erosion, the dangersof flood, the rock surface and laboratory parameters analyzed include physical properties, textureand chemical properties of the soil pH, soil cation exchanges capacity, base saturation, C-organic,and soil salinity. The results showed that the actual land suitability classes for sample 1 is S2rc,nr,sample 2 is S3nr, sample 3 is S2oa,rc,nr,eh, sample 4 is S3nr,eh, sample 5 is S3nr, sample 6 is S3nr,sample 7 is Nrc, sample 8 is S3nr, sample 9 is S3tc,rc,nr, sample 10 is S3tc, sample 11 is S3nr,sample 12 is S3tc,oa,rc,nr, sample 13 is S3tc,nr, sample 14 is S3tc,rc, sample 15 is S3tc,nr,uh, andsample 16 is Nrc. Potential land suitability classes for sample 1 is S2rc, sample 2 is S2rc,nr, sample3 is S2rc, sample 4 is S2rc,nr,eh, sample 5 is S2rc,nr, sample 6 is S3rc,nr, sample 7 is Nrc, sample 8is S2rc,nr, sample 9 is S3tc,rc, sample 10 is S3tc, sample 11 is S2rc,nr, sample 12 is S3tc,rc, sample13 is S3tc, sample 14 is S3tc,rc, sample 15 is S3tc, and sample 16 is Nrc

The Different Magnetic Results of Anemi and PPM Measurements on the Buried Remains of a 13th Century Fortress

This study aimed to evaluate the different magnetic results of an electromagnetic induction with proton magnetometer measurements on an archaeological site. The electromagnetic induction allows measuring both the apparent magnetic susceptibility in part per thousand (ppt) and the apparent electrical conductivity in millisiemens (mS/m). A proton magnetometer measures the total magnetic intensity in nanotesla (nT), caused by the induced and remanent magnetisations. An archaeological site where historical documents indicated the presence of a 13th century fortress that built by Lamuri Sultanate was selected as a test area. The measurement were conducted by divided the study area into 10 profiles.Some standard data processing have been applied to the measured data. The result of the first survey with electromagnetic induction showed low magnetic anomalies in the buried remains of Lamuri fortress. The similar value are shown as well by low magnetic field intensity in magnetometer measurement

Investigation of Shallow Paleochannel in Banda Aceh Based on Electrical Resistivity Tomography

Pembentukan daratan pesisir sangat dipengaruhi oleh proses sedimentasi dari material hasil rombakan. Proses sedimentasi pada masa lampau dapat dikaji dengan mempelajari sungai purba sebagai media transportasi material. Survey geofisika metode electrical resistivty tomography dilakukan untuk investigasi sungai purba di Ulee Kareng Banda Aceh. Untuk memetakan sedimen dan geometri sungai purba, pengukuran electrical resistivity dilakukan di sepanjang dua lintasan dengan panjang 240 meter dan spasi elektroda 2 meter. Proses inversi model resistivitas 2D telah dilakukan pada masing – masing lintasan data yang terukur. Hasil electrical resistivity tomography mampu membedakan batas – batas antara setiap lapisan sedimen yang terendapkan di lokasi paleochannel. Sedimen paleochannel secara jelas diidentifikasi dari distribusi nilai resistivitas yang lebih tinggi (15.2–31.6 Ω.m). Berdasarkan interpretasi dari metode electrical resistivity tomography area persawahan merupakan lokasi sungai purba pada masa lampau. The formation of coastal area is influenced by sedimentation process. The sedimentation process along the coastal line in the past one can be explained by studying existence of paleochannels located around the area. Deposition of the sediment along the coast is carried by river activities in the past. We have investigated paleochannel structure in Ulee Kareng, Banda Aceh using electrical resistivity tomography survey. The measurements were performed along two profiles with 240 meters and 2 meters spacing between electrodes crossing the paddy. The method measured apparent resistivity data along the profiles. The 2D resistivity models were inverted from the apparent resistivity data using Res2Div program. The inverted models clearly show indication of paleochannel structure based on distribution of resistivity values within the subsurface. The paleochannel area was characterize by high resistivity i.e. 15.2–31.6 Ω.m

Geografi budaya dalam wilayah pembangunan daerah Sumatera Barat

Sebagaimana diketahui, lingkungan alami mencakup tanah, iklim, sungai, dataran, pegunungan, flora, fauna, geologi, dan hidrologi dengan seluk beluknya. Selanjutnya, aspek sosial budaya antara lain mencakup agama/kepercayaan, teknologi, material, ekonomi, organisasi sosial, dan bahasa. lnformasi tentang unsur-unsur tersebut tidak dihimpun seluruhnya, tetapi terbatas pada unsur-unsur agama/kepercayaan, teknologi, ekonomi, peternakan, perikanan, pertam bangan, perindustrian, dan perdagangan. Daerah penelitian untuk menghimpun informasi tersebut di atas adalah setiap wilayah pembangunan yang ada di Propinsi Sumatera Barat, melalui wilayah sampelnya masing-masing

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030