Why Is the Attic Ventilation Disappearing from the Current Urban Houses in the Humid Tropics?

The construction of a townhouse built today no longer has roof vents, compared to colonial buildings as well as traditional architecture scattered in humid tropics. In Indonesia, many buildings are made with a zinc roof, even in North Sulawesi province 92 percent of zinc roofed buildings or metal aluminum. This article has two purposes, the first is to assess the benefits of attic ventilation, especially for zinc roofed buildings and the second is to find out why the ventilation loft is no longer used to present buildings. Research by building two same test cells where one cell has roof vents, and the other cell does not. The test cell with ventilated roofs has the advantage that the interior temperatures are lower on average by 1.2 ∘C than those in a cell without ventilation. Almost all buildings today have a modern and minimalist style where the shape and pattern are delicate and do not allow for roof ventilation; such structures cannot form adequate attic spaces. Based on observation and evaluation, this is the leading cause of the disappearing of attic ventilation. Another thing was caused by efforts to reduce the selling price of a house with consideration of people’s purchasing power. Ignorance from building owners and developers on the benefits of attic ventilation to reduce room temperature and lighting is one of the factors found in this study; even this problem is made worse by architects who often ignore these benefits in their designs. Comprehensive knowledge is needed for the general public and also for architects for the use of roof ventilation which in turn is an effort to achieve thermal comfort and energy savings in the domestic sector     Keywords: attic ventilation, urban houses, modern and minimalist style, thermal comfort, energy savings, humid tropical region

Prarancangan Pabrik Etil Asetat Dari Asam Asetat Dan Etanol Dengan Katalis Asam Sulfat Kapasitas 45.000 Ton Per Tahun

Etil asetat merupakan cairan tidak berwarna yang mudah larut dalam air dan pelarut organik, yang mempunyai kegunaan sebagai bahan pelarut organik dalam industri pembuatan tinta, pembuatan resin serta dalam industri farmasi dan kosmetik. Untuk memenuhi kebutuhan etil asetat dalam negeri dirancang pabrik etil asetat dari etanol dan asam asetat dengan kapasitas 45.000 ton per tahun dan tidak menutup kemungkinan untuk diekspor. Proses pembuatan Etil asetat menggunakan reaksi esterifikasi etanol dan asam asetat dengan katalis asam sulfat, dilakukan di dalam Reaktor Alir Tangki Berpengaduk (RATB). Pembangunan pabrik berada di Gresik Jawa Timur. Pabrik ini membutuhkan bahan baku etanol sebanyak 53.505,16 ton per tahun yang diperoleh dari PT. Molindo Raya Industrial di Malang dan PT. Eterindo Wahantama di Gresik Jawa Timur, sedangkan asam asetat sebanyak 59.200,87 ton per tahun diperoleh dari PT. Indo Acidatama di Surakarta dan showa esterindo di Cilegon Banten. Reaksi berlangsung pada fase cair, suhu 70ºC dan tekanan 1 atm. Untuk memperoleh produk etil asetat dengan kemurnian 99%. dilakukan proses distilasi. Bentuk perusahaan adalah perseroan terbatas (PT). Dalam pelaksanaan proses, pabrik membutuhkan karyawan sebanyak 96 orang. Kebutuhan unit pendukung proses pabrik etil asetat meliputi 6.297.112.623,01 liter air per tahun, 1.700.609.196,92 kg steam per tahun, 25.414.939,60 liter bahan bakar per tahun, dan 2.225.359,69 kW listrik per tahun. Dari hasil analisis ekonomi diperoleh hasil yaitu Percent Return On Investment (ROI) sebelum pajak sebesar 59,63% dan setelah pajak sebesar 41,74%. Pay Out Time (POT) sebelum pajak sebesar 1,44 tahun sedangkan setelah pajak sebesar 1,93 tahun. Break Even Point (BEP) sebesar 37,76%, dan Shut Down Point (SDP) sebesar 23,21%. Discounted Cash Flow (DCF) sebesar 35 %. Berdasarkan data di atas maka pabrik etil asetat dari asam asetat dan etanol ini layak untuk didirikan

PENGEMBANGAN OBJEK WISATA BAHARI DI LIKUPANG TIMUR (STUDI KASUS : PANTAI PULISAN)

Desa Pulisan merupakan salah satu destinasi wisata yang sangat potensial di kembangkan yang terletak di Kecamatan Likupang Timur Kabupaten Minahasa Utara. Di desa ini terdapat beberapa objek wisata menarik seperti pantai, goa dan terumbu karang bawah laut. Sehingga menarik banyak wisatawan baik domestik maupun wisatawan asing datang berkunjung ke desa ini. Namun akses menuju ke desa ini masih belum memadai karena kondisi infrastruktur jalan yang masih belum diperbaiki. Di tambah pula sarana dan prasarana serta fasilitas penunjang pariwisata lainnya belum tersedia. Penelitian ini bertujuan untuk mengidentifikasi potensi–potensi wisata yang ada di desa Pulisan, kemudian membuat strategi pengembangannya. Metode yang digunakan dalam penelitian ini adalah Analisis SWOT dengan dengan menggunakan matriks IFAS dan EFAS dan matriks SWOT. Matriks SWOT menunjukkan arahan dan strategi pengembangan potensi objek wisata Pantai Pulisan.Hasil penelitian ini menunjukan bahwa objek wisata yang ada di Desa Pulisan sangat berpeluang untuk dikembangkan sebagai salah satu objek wisata yang ada di Kabupaten Minahasa Utara hal tersebut dilihat dari hasil analisis Strength (Kekuatan) yaitu Desa Pulisan memiliki pantai dengan daya tarik flora dan fauna yang indah, pemandangan laut yang masih alami dan pasir putih yang asri serta keindahan terumbu karang bawah laut yang tak kalah menariknya dengan Taman Laut Bunaken. Sedangkan Opportunities (peluang) dengan dikembangkannya objek wisata ini dapat membuka lapangan pekerjaan untuk masyakarat sekitar dan  menambah Pendapatan Asli Daerah (PAD) Kabupaten Minahasa Utara. Kata Kunci: Pengembangan, Wisata, Bahari, Desa Pulisa

Pengaruh Variasi Garam Ammonium Terhadap Keasaman Zeolit Alam Pada Reaksi Perengkahan Minyak Jelantah

Natural zeolite modification with the addition of ammonium salt variations was conducted. The modification was conducted by demineralization method, dealumination and followed by activation of ammonium salt. The types of activators were ammonium chloride, ammonium nitrate and ammonium fluoride. The effect of ammonium salt was assessed through acidity parameter with Si/Al ratio variable and applied catalyst for catalytic cracking of waste cooking oil. The results showed that the activation of natural zeolite by using ammonium chloride salt could increase the acidity of natural zeolite with the highest Si/Al ratio about 15.56. Based on the XRF analysis showed that the reduced amount of Na metal in zeolite about 92.8%. The effect of ammonium salt variation on the acidity of natural zeolites was observed by applying a catalyst in the catalytic cracking of waste cooking oil. Physical characteristic of catalytic cracking products from waste cooking oil indicated all products fulfill the solar standards requirement. The results concluded that ammonium chloride salt was the best activator in natural zeolite modification and generally all ammonium salts gave high acidity effect to natural zeolite in catalytic cracking of waste cooking oil

Widening the Adaptation of White Clover by Incorporation of Valuable New Traits from Wild Clover Species

Although white clover (Trifolium repens) is the most widely used legume in grazed pastures of temperate and sub-tropical regions, it is severely restricted in genetic diversity for adaptive traits to low soil fertility and other stress environments, including drought. The objective of this research was to transfer traits for wider adaptation from other clover species by hybridisation. Eight Trifolium species with contrasting adaptations were shown by DNA sequence phylogenetics to be closely related to white clover. Interspecific hybridisation was undertaken among these species using embryo rescue, and an array of partially fertile F1 hybrids was obtained. Population development from these F1 hybrids showed that hybrids involving six taxa could be selected for high sexual fertility. Most showed strong inter-species chromosome pairing and the potential for introgression of exotic genomes into white clover. Several of the new genomic combinations, which do not occur in nature, will improve prospects for extending the adaptive range of white clover

Climatic controls on peatland black spruce growth in relation to water table variation and precipitation

Prior research has demonstrated the importance of water limitations and increasing temperatures on upland black spruce (Picea mariana [Mill.] B.S.P.) tree growth, which is a dominant component of the North American boreal forest. However, little work has been done to investigate the connectivity between growth and hydro‐climate in peatland black spruce systems. The boreal forest is the largest global terrestrial biome and is highly threatened due to current and projected increases in temperatures for the northern latitudes. Here we explore the dynamics among annual black spruce growth, climate, and water table elevations using 45 years of in situ precipitation, temperature, and water table elevation coupled with dendrochronological analysis from six research peatlands at the Marcell Experimental Forest, MN, USA. From 1963 to 2010, we found weak relationships between water table elevation and black spruce growth at the six study sites. Instead, annual black spruce growth was most favourable during three climatic periods: (a) cool, moist conditions in mid‐summer; (b) warm mid‐spring temperatures; and (c) cool temperatures in the fall prior to the current growing season. The disconnect between black spruce growth and water table dynamics was surprising and suggests that either annual black spruce growth is minimally responsive to hydrological fluctuations at the timescale we analysed or there is great elasticity of black spruce growth to peatland water table and evapotranspiration dynamics under the range of hydrological fluctuations contained in our record

Effectiveness and cost-effectiveness of sentinel lymph node biopsy compared with axillary node dissection in patients with early-stage breast cancer: a decision model analysis

BACKGROUND: Sentinel lymph node biopsy (SLNB) is less invasive than axillary lymph node dissection (ALND) for staging early breast cancer, and has a lower risk of arm lymphoedema and similar rates of locoregional recurrence up to 8 years. This study estimates the longer-term effectiveness and cost-effectiveness of SLNB. METHODS: A Markov decision model was developed to estimate the incremental quality-adjusted life years (QALYs) and costs of an SLNB-based staging and management strategy compared with ALND over 20 years’ follow-up. The probability and quality-of-life weighting (utility) of outcomes were estimated from published data and population statistics. Costs were estimated from the perspective of the Australian health care system. The model was used to identify key factors affecting treatment decisions. RESULTS: The SLNB was more effective and less costly than the ALND over 20 years, with 8 QALYs gained and $883 000 saved per 1000 patients. The SLNB was less effective when: SLNB false negative (FN) rate >13%; 5-year incidence of axillary recurrence after an SLNB FN>19%; risk of an SLNB-positive result >48%; lymphoedema prevalence after ALND <14%; or lymphoedema utility decrement <0.012. CONCLUSION: The long-term advantage of SLNB over ALND was modest and sensitive to variations in key assumptions, indicating a need for reliable information on lymphoedema incidence and disutility following SLNB. In addition to awaiting longer-term trial data, risk models to better identify patients at high risk of axillary metastasis will be valuable to inform decision-making.H. Verry, S.J. Lord, A. Martin, G. Gill, C.K. Lee, K. Howard, N. Wetzig and J. Sime