STUDI EKSPERIMENTAL PERBANDINGAN PENGARUH POSISI PEMBEBANAN MONOTONIK PADA PELAT STRIP KOMPOSIT BETON-BAJA RINGAN DENGAN PENGHUBUNG GESER BAUT

ABSTRAK Perkembangan ilmu pengetahuan dan teknologi semakin pesat dalam pembangunan infrastruktur. Dalam pembangunan itu tidak terlepas dari material pembentuknya. Salah satu material yang paling banyak dikenal yaitu material komposit. Saat ini material struktur komposit yang sedang banyak diteliti adalah komposit beton-baja ringan. Dalam penelitian ini membahas tentang hasil studi eksperimental respon penggunaan baut sebagai penghubung geser (shear connector) pada komponen struktur pelat strip komposit beton-baja ringan terhadap kapasitas lentur ketika diberikan beban serta mengamati pengaruh penghubung geser terhadap slip yang terjadi. Model benda uji didisain menggunakan material baja ringan profil kanal C.75.75 merk TASO sebagai tulangan tarik dan material beton ready mix dengan mutu 25,1 MPa. Benda uji dibuat sebanyak tiga buah spesimen berupa pelat strip dengan variasi ketebalan yang berbeda-beda yakni 80 mm, 100 mm, 120 dengan menggunakan penghubung geser (shear connector) baut berdiameter 5,5 mm dengan bentang geser 0,65 m dan tiga buah spesimen lainnya dengan ketebalan sama dengan bentang geser 0,80 m yang telah diuji oleh penguji sebelumnya sebagai pembanding. Hasil uji didapatkan bahwa semakin dekat beban dengan tumpuan dan semakin tebal spesimen strip maka semakin besar pula beban yang dipikul oleh spesimen. Kemudian selama pengujian tidak ditemukan adanya slip pada semua spesimen. Kata Kunci: Komposit, Pelat strip komposit beton-baja ringan, Penghubung geser, baut

Progress on agriculture in the UN climate talks: How COP21 can ensure a food-secure future

Agriculture, and consequently food security and livelihoods, is already being affected by climate change, according to latest science from the IPCC (Porter et al. 2014). The IPCC agrees that the world needs to produce at least 50% more food than we do today in order to meet the goal of feeding a projected 9 billion people by 2050. This must be achieved in the face of climatic variability and change, growing constraints on water and land for crops and livestock, and declining wild capture fishery stocks. Although the protection of food security lies within the core objective of the United Nations Framework Convention on Climate Change (UNFCCC) (Article 2), formal arrangements for addressing agriculture within COP21 are unlikely. CGIAR would welcome the strengthening of aspirations for food security through action on mitigation and adaptation within a new agreement. We recognise that the new climate agreement is unlikely to be prescriptive about how adaptation in agriculture is supported and how agriculture might contribute to emission cuts. These issues are addressed within countries’ INDCs and determined at national level

Predicting aboveground forest biomass with topographic variables in human-impacted tropical dry forest landscapes

Topographic variables such as slope and elevation partially explain spatial variations in aboveground biomass (AGB) within landscapes. Human activities that impact vegetation, such as cattle grazing and shifting cultivation, often follow topographic features and also play a key role in determining AGB patterns, although these effects may be moderated by accessibility. In this study, we evaluated the potential to predict AGB in a rural landscape, using a set of topographical variables in combination with indicators of accessibility. We modeled linear and non-linear relationships between AGB, topographic variables within the territorial boundaries of six rural communities, and distance to roads. Linear models showed that elevation, slope, topographic wetness index, and tangential curvature could explain up to 21% of AGB. Non-linear models found threshold values for the relationship between AGB and diffuse insolation, topographic position index at 19 × 19 pixels scale and differentiated between groups of communities, improving AGB predictions to 33%. We also found a continuous and positive effect on AGB with increased distance from roads, but also a piecewise relationship that improves the understanding of intensity of human activities. These findings could enable AGB baselines to be constructed at landscape level using freely available data from topographic maps. Such baselines may be of use in national programs under the international policy Reducing Emissions from Deforestation and Forest Degradation

In vitro effects of zinc on the cytokine production from peripheral blood mononuclear cells in patients with zinc allergy.

Metals, such as nickel, cobalt, chromium and zinc, are ubiquitous in the environment. Systemic reactions, including hand dermatitis and generalized eczematous reactions, can be caused by the dietary ingestion of metals. In this study, we aimed to determine whether the cytokine production from peripheral blood mononuclear cells (PBMCs) obtained from zinc allergy patients can be used as a sensitive marker to investigate zinc-allergic contact dermatitis. The diagnosis of sensitivity to metal was made based on the results of a metal patch test. The PBMCs were stimulated with various concentrations (5-100 μM) of zinc sulfate (ZnSO4) for 24 h. The culture supernatants were collected and analyzed using ELISA for measurement of the cytokine production. The levels of IFN-γ, TNF-α, IL-1β, IL-5, IL-13 and MIF were significantly higher in the zinc-allergic patients (n = 5) than in the healthy controls (n = 5) at 100 μM of ZnSO4 stimulation. Although, patch testing is considered as standard test to diagnose metal allergy but false-positive and -negative reactions may limit its use in conditions of existing dermatitis. Therefore, this study suggest that in support of patch testing the determination of cytokine production using PBMCs cultures would be helpful for making an early diagnosis of such conditions

Simple incentives and group dependence for successful payments for ecosystem services programs: evidence from an experimental game in rural Lao PDR

In this paper, we use a new game-based tool to evaluate the immediate and longer-term behavioral change potential of three different payment for environmental services (PES) delivery mechanisms: direct payments for individual performance, direct payments for group performance and insurance. Results from four rural shifting-cultivation dependent communities in Lao PDR suggest that easily understood group-oriented incentives yield the greatest immediate resource-use reduction and experience less free-riding. Group-based incentives may succeed because they motivate participants to communicate about strategies and coordinate their actions and are perceived as fair. No incentive had a lasting effect after it ceased, but neither did any crowd out the participants’ baseline behavior. Temporary reductions in resource dependence may provide a buffer for development of new livelihoods and longer-term change. Games like the one developed here can help policymakers appropriately target environmental incentive programs to local contexts and teach program participants how incentive schemes work

The Role of Agriculture in the UN Climate Talks

Agriculture, and consequently food security and livelihoods, is already being affected by climate change, according to latest science from the IPCC. The various strands of work already underway on agriculture within the UNFCCC process can be strengthened and made more coherent. A 2015 climate agreement should reference food production and provide the financial, technical and capacity building support for countries to devise ambitious actions for the agricultural sector. A new climate agreement should be consistent with the Sustainable Development Goal (SDG) proces

A data support infrastructure for Clean Development Mechanism forestry implementation: an inventory perspective from Cameroon

Clean Development Mechanism (CDM) forestry project development requires highly multi-disciplinary and multiple-source information that can be complex, cumbersome and costly to acquire. Yet developing countries in which CDM projects are created and implemented are often data poor environments and unable to meet such complex information requirements. Using Cameroon as an example, the present paper explores the structure of an enabling host country data support infrastructure for CDM forestry implementation, and also assesses the supply potential of current forestry information. Results include a conceptual data model of CDM project data needs; the list of meso- and macro-level data and information requirements (Demand analysis); and an inventory of relevant data available in Cameroon (Supply analysis). From a comparison of demand and supply, we confirm that data availability and the relevant infrastructure for data or information generation is inadequate for supporting carbon forestry at the micro, meso and macro-levels in Cameroon. The results suggest that current CDM afforestation and reforestation information demands are almost impenetrable for local communities in host countries and pose a number of cross-scale barriers to project adoption. More importantly, we identify proactive regulatory, institutional and capacity building policy strategies for forest data management improvements that could enhance biosphere carbon management uptake in poor countries. CDM forestry information research needs are also highlighted

KINETIKA FERMENTASI PADA TEH KOMBUCHA DENGAN VARIASI JENIS TEH BERDASARKAN PENGOLAHANNYA

Teh (Camellia sinensis) merupakan hasil pertanian yang mengandung senyawa berkhasiat, terutama dalam bidang kesehatan. Beberapa jenis teh di Indonesia adalah teh hijau dan teh hitam. Teh kombucha merupakan air seduhan teh dan gula yang mengalami proses fermentasi selama 8-12 hari yang tersusun dari senyawa kompleks yang diubah oleh bakteri Acetobacter xylinum dan khamir Saccharomyces cereviseae. Tujuan penelitian ini adalah untuk mengetahui pengaruh jenis teh terhadap kinetika fermentasi teh kombucha dengan parameter kecepatan pertumbuhan spesifik (µ), hasil pertumbuhan sel (YX/S), pembentukan produk (YP/S), waktu generasi (Td), dan banyaknya penggandaan (N). Penelitian dilakukan di UPT Laboratorium Pusat MIPA Universitas Sebelas Maret Surakarta. Optimasi proses fermentasi dilakukan dengan jumlah inokulum 10 % (v/v), suhu 30ºC dan kadar gula awal 10 % (b/v). Analisis terhadap kadar gula reduksi, kadar asam asetat, pH, dan mikrobiologis teh kombucha dilakukan selama 8 hari fermentasi dengan interval 24 jam. Data yang diperoleh akan dilakukan analisis secara deskriptif dan uji t-test sehingga dapat diketahui perbedaan kinetika fermentasi teh kombucha hijau dan teh kombucha hitam. Hasil penelitian menunjukkan bahwa kinetika fermentasi kombucha teh hijau kecepatan partumbuhan spesifik aerob dan anaerob yaitu 0,055/jam dan 0,015/jam; hasil pertumbuhan sel 1,901 x 107 cfu/mg; pembentukan produk 0,064; effisiensi produksi asam asetat terhadap gula reduksi 11,814 %; waktu generasi dalam suasana aerob dan anaerob 12,6 jam dan 46,2 jam; dan banyaknya penggandaan 3,583 kali. Sedangkan kinetika fermentasi kombucha teh hitam menunjukkan kecepatan partumbuhan spesifik aerob dan anaerob yaitu 0,054/jam dan 0,018/jam; hasil pertumbuhan sel 2,425 x 107 cfu/mg ; pembentukan produk 0,081; effisiensi produksi asam asetat terhadap gula reduksi 11,510 %; waktu generasi dalam suasana aerob dan anaerob 12,8 jam dan 38,5 jam; dan banyaknya penggandaan 3,583 kali. Dengan uji t-test didapatkan hasil bahwa kecepatan pertumbuhan spesfik aerob, efisiensi produksi asam asetat terhadap gula reduksi, waktu generasi aerob, pertumbuhan sel dan pembentukan produk adalah tidak beda nyata. Sedangkan kecepatan pertumbuhan spesifik anaerob, waktu generasi anaerob, dan banyaknya penggandaan adalah beda nyata

Pengaruh Orientasi Kewirausahaan Terhadap Kinerja Usaha Pada Agroindustri Kopi Bubuk Di Nagari Koto Tuo Kecamatan Sungai Tarab Kabupaten Tanah Datar

PENGARUH ORIENTASI KEWIRAUSAHAAN TERHADAP KINERJA USAHA PADA AGROINDUSTRI KOPI BUBUK DI NAGARI KOTO TUO KECAMATAN SUNGAI TARAB KABUPATEN TANAH DATAR Abstrak Perkebunan merupakan sektor kunci dari industri pertanian dan memberikan kontribusi yang signifikan terhadap perekonomian nasional. Kopi merupakan salah satu tanaman yang dibudidayakan di Indonesia sebagai salah satu komoditi ekspor. Agroindustri kopi yang mengubah biji kopi menjadi barang olahan seperti kopi bubuk, dimana pelaku usaha yang terlibat harus sadar akan orientasi kewirausahaan perlu adanya agar kinerja usaha dari agroindustri kopi dapat berjalan dengan baik. Penelitian ini bertujuan untuk mendeskripsikan orientasi kewirausahaan dan kinerja usaha serta menganalisis pengaruh orientasi kewirausahaan terhadap kinerja usaha pada agroindustri kopi bubuk di Nagari Koto Tuo Kecamatan Sungai Tarab Kabupaten Tanah Datar. Penelitian ini menggunakan metode deskriptif dan kuantitatif, dengan bantuan SPSS, untuk menganalisis data yang dikumpulkan dari 40 pengusaha kopi bubuk. Studi menemukan bahwa pengusaha kopi bubuk di Nagari Koto Tuo memiliki orientasi kewirausahaan karena inovatif, proaktif, dan berani mengambil risiko. Pengusaha kopi bubuk juga berkinerja baik dalam bisnis. Analisis SPSS menunjukkan bahwa orientasi kewirausahaan berpengaruh positif terhadap kinerja usaha. Kata kunci : orientasi kewirausahaan, kinerja usaha, kopi bubuk, agroindustr