Peningkatan Mutu Arang Aktif Kulit Kayu Mangium

Penelitian ini bertujuan untuk mengetahui pengaruh suhu aktivasi, waktu aktivasi dan konsentrasi asam fosfat (H,PO,) terhadap hasil dan mutu arang aktif yang dihasilkan. Proses pembuatan arang aktif dilakukan dengan menggunakan retor yang terbuat dari baja tahan karat yang dilengkapi dengan elemen listrik pada suhu 750 dan 850°(dengan lama waktu aktivasi 90, 120 dan 150 menit Bahan pengaktif yang digunakan adalah larutan asam fosfat (H,PO,) dengan konsentrasi 0,0 dan 5,0%). Hasil penelitian menunjukkan bahwa kondisi optimum untuk membuat arang aktif dengan kualitas terbaik dihasilkan dari arang yang diaktivasi pada suhu 750°C selama 90 menit dengan konsentrasi H,PO, sebesar 5 %. Pada perlakuan ini rendemen yang dihasilkan sebesar 43,56%, kadar air 5,44%, kadar abu 8,01 %, kadar zat terbang 11,40%, kadar karbon terikat 80,60%, daya serap terhadap benzena 18,60% dan dengan daya serap terhadap yoclium sebesar 912,6 mg/g. Nilai daya serap yang diperoleh ini memenuhi syarat Standar asional Indonesia dan dapat digunakan untuk menjernihkan ai

Mechanized recovery of olive pruning residues: ash contamination and harvesting losses

Agricultural residues represent an important source of biomass for energy. Among the available biomass suitable for energy and available in Italy, pruning represents about the 20% of the total. About 1.184 million of hectares are planted with olive trees; the pruning residues coming from these plantations represent a wide source of biomass at National level. The authors tested six commercial pruning harvesters to determine harvesting losses and product contamination when recovering pruning residues. All harvesters used a mechanical pick-up to collect the residues and a shredder to reduce them into chips. Three different pick-up settings were tested and namely: 1 cm above ground level, manufacturer’s specification and 3 cm above ground level. Ash content in the shredded material was taken as a measure of contamination: the uncontaminated branch material collected directly from the trees had a value of 3.5%, whereas in shredded residues varied between 4.5% and over 5.5%, for the shortest and the longest distance between the pick-up and the soil surface, respectively. Harvesting losses were slightly, but significantly, related to pick-up setting, and mainly depended on machine type. Both machines have shown a good quality of the work performed and the results obtained indicates that the work phases could be simplified in order to reduce both the time of use and the harvesting costs

Penyempurnaan Sifat Papan Serat Kerapatan Sedang Dari Pelepah Nipah Dan Campurannya Dengan Sabut Kelapa

Dewasa ini, potensi bahan serat konvensional (khususnya kayu) untuk pembuatan papan serat berkerapatan sedang (MDF) semakin terbatas dan langka. Penggunaan bahan serat alternatif yang tersedia berlimpah dan belum banyak dimanfaatkan, yaitu pelepah nipah dan sabut kelapa, telah dicoba untuk MDF, menggunakan perekat urea formaldehida (UF). Akan tetapi, sifat produk MDF sebagian besar tidak memenuhi persyaratan JIS dan ISO. Sebagai kaitannya, percobaan perbaikan sifat MDF dilakukan dengan tetap menggunakan ke dua macam bahan serat tersebut. Mula-mula masing-masing bahan serat diperiksa sifat dasarnya yaitu berat jenis, komposisi kimia, dan dimensi serat dan nilai turunannya. Pengolahan pulp untuk MDF menerapkan proses semi-kimia soda panas terbuka (bertekanan atmosfir) pada 2 taraf konsentrasi alkali (8% dan 12%). Pulp yang dihasilkan kemudian ditambahkan bahan aditif berupa alum 5%, bahan perekat tanin formaldehida (TF) baik dikombinasikan dengan arang aktif 5% atau tidak; dan selanjutnya dibentuk menjadi lembaran MDF dengan cara basah. MDF tersebut lalu diperiksa sifat fisis-mekanis dan emisi formaldehida. Hasil pencermatan sifat fisis-mekanis mengindikasikan bahwa serat pelepah nipah lebih prospektif untuk MDF dibandingkan sabut kelapa. Arang aktif berakibat penurunan sifat kekuatan/mekanis MDF dan emisi formaldehida, tetapi memperbaiki kestabilan dimensinya. Sifat MDF dari pelepah nipah 100% paling banyak mendekati persyaratan (JIS dan ISO). Meskipun demikian, sabut kelapa diharapkan bisa prospektif untuk MDF dengan mencampurnya bentuk pulp) dengan pulp pelepah nipah pada proporsi (b/b) 25%+75% dan 50%+50%. MDF yang menggunakan perekat TF memiliki sifat lebih baik dibandingkan MDF percobaan sebelumnya (menggunakan perekat UF), antara lain kekuatan lebih tinggi, emisi formaldehida lebih rendah, dan lebih banyak memenuhi persyaratan JIS dan ISO

Desain Dan Pengujian Kinerja Kompor Gasifikasi-pirolisis

This paper deals with the design and performance test of pyrolysis burning stoves that produce energy for cooking and biochar. The stove consists of two section chambers, namelycombustion chamber that produces activation heat for pyrolysis process and energy for cooking, andpyrolysis chamber that produces biochar and volatile matter (syngas and tar in gas form). Volatile matter product was introduced to the combustion chamber in addition to the biomass there and replaces biomass fuel gradually to produce energy for cooking and keeping the continuous pyrolysis process (autothermal). Methode used for performance test: direct observations/measurements and Water Boilling Test (WBT). Result of performance test: the autothermal process was going well until resulting a 100% biochar for most of the biomass used. Thermal efficiency of the stove was 11.3% (before pyrolysis) and 14.72% (after pyrolysis), excluding heat to produce biochar. Time needed to boil a 5 L water was 12 minutes before pyrolysis and 6 minutes after pyrolysis. Output power ranges from 9.60 kW to 23.16 kW. The maximum temperature reached 868 °C at the pan and 860oC in combustion chamber.Input biomass capacity depending on the type of feedstock ranging from 1200 - 3000 g/process, resulting in 507-900 g biochar/process, to give biochar ratio to raw materials from 23.0% to 44.8%. All maximum conditions occurs when volatilematters produced from pyrolysis process were burned, which showed that burning volatile matters is better than burning solid biomass directly.The amount of biochar produced by this stove was three times higher compared to anila stove, with less of smoke during the biochar production

Struktur Populasi dan Performans Reproduski Ternak Babi di Kabupaten Sumba Timur

Penelitian ini bertujuan untuk mengetahui struktur populasi dan performans reproduksi ternak babi di Kabupaten Sumba Timur. Penelitian dilaksanakan dari bulan Februari sampai dengan Mei 2017 dengan metode penelitian yang digunakan adalah survei dengan wawancara langsung terhadap 200 responden. Data dianalisis dengan pendekatan statistik deskriptif yang digambarkan pada tabel frekuensi dari setiap indikator. Variabel yang diukur adalah struktur populasi jantan dan betina yang meliputi anak (0-3 bulan), muda (3-8 bulan), dewasa (>8 bulan). Sedangkan performans reproduksi meliputi lama estrus, siklus estrus, litter size, jumlah sapih, angka mortalitas. Hasil penelitian menunjukkan bahwa struktur populasi ternak babi di dominasi ternak betina: jantan secara berurutan meliputi anak 53.39:46.61%, muda 57.50:42,50%, dewasa 54.17: 45,83%. Sedangkan performans reproduksi ternak babi yakni lama estrus 3,25 hari, siklus estrus 20,45 hari, liter size 9,75 ekor serta mortalitas 17,03%. Dengan demikian dapat disimpulkan bahwa struktur populasi ternak babi didominasi ternak betina. Sedangkan performans reproduksi induk ternak babi tergolong dalam kategori baik

What Patients Want to Know about Imaging Examinations: A Multiinstitutional U.S. Survey in Adult and Pediatric Teaching Hospitals on Patient Preferences for Receiving Information before Radiologic Examinations

Purpose To identify what information patients and parents or caregivers found useful before an imaging examination, from whom they preferred to receive information, and how those preferences related to patient-specific variables including demographics and prior radiologic examinations. Materials and Methods A 24-item survey was distributed at three pediatric and three adult hospitals between January and May 2015. The χ2 or Fisher exact test (categorical variables) and one-way analysis of variance or two-sample t test (continuous variables) were used for comparisons. Multivariate logistic regression was used to determine associations between responses and demographics. Results Of 1742 surveys, 1542 (89%) were returned (381 partial, 1161 completed). Mean respondent age was 46.2 years ± 16.8 (standard deviation), with respondents more frequently female (1025 of 1506, 68%) and Caucasian (1132 of 1504, 75%). Overall, 78% (1117 of 1438) reported receiving information about their examination most commonly from the ordering provider (824 of 1292, 64%), who was also the most preferred source (1005 of 1388, 72%). Scheduled magnetic resonance (MR) imaging or nuclear medicine examinations (P < .001 vs other examination types) and increasing education (P = .008) were associated with higher rates of receiving information. Half of respondents (757 of 1452, 52%) sought information themselves. The highest importance scores for pre-examination information (Likert scale ≥4) was most frequently assigned to information on examination preparation and least frequently assigned to whether an alternative radiation-free examination could be used (74% vs 54%; P < .001). Conclusion Delivery of pre-examination information for radiologic examinations is suboptimal, with half of all patients and caregivers seeking information on their own. Ordering providers are the predominant and preferred source of examination-related information, with respondents placing highest importance on information related to examination preparation

Strain control of band topology and surface states in antiferromagnetic EuCd2_2As2_2

Topological semimetal antiferromagnets provide a rich source of exotic topological states which can be controlled by manipulating the orientation of the N\'eel vector, or by modulating the lattice parameters through strain. We investigate via ${ab\ initio}$ density functional theory calculations, the effects of shear strain on the bulk and surface states n two antiferromagnetic EuCd$_2$As$_2$ phases with out-of-plane and in-plane spin configurations. When magnetic moments are along the $\textit{c}$-axis, a $3\%$ longitudinal or diagonal shear strain can tune the Dirac semimetal phase to an axion insulator phase, characterized by the parity-based invariant $\eta_{4I} = 2$. For an in-plane magnetic order, the axion insulator phase remains robust under all shear strains. We further find that for both magnetic orders, the bulk gap increases and a surface gap opens on the (001) surface up to 16 meV. Because of a nonzero $\eta_{4I}$ index and gapped states on the (001) surface, hinge modes are expected to happen on the side surface states between those gapped surface states. This result can provide a valuable insight in the realization of the long-sought axion states.Comment: 5 pages, 4 figure

Penyempurnaan Sifat Papan Serat Berkerapatan Tinggi Dari Campuran Rumput Gelagah, Tandan Kosong Kelapa Sawit, Dan Bambu

Papan serat hardboard (HB) dari campuran Rumput Gelagah (RG), Tandan Kosong Kelapa Sawit (TKKS) dan bambu andong berpotensi untuk dikembangkan. Namun, percobaan pendahuluan menunjukkan HB tersebut tidak memenuhi persyaratan produk HB dari Japanese Industrial Standard (JIS) dan International Standard Organization (ISO). Tulisan ini mempelajari modifikasi pembuatan HB agar memenuhi standar produk tersebut. Modifikasi yang dilakukan meliputi penambahan konsentrasi alkali dalam pemasakan pulp dan merubah komposisi perekat. Hasil penelitian menunjukkan kualitas HB modifikasi meningkat dan mampu memenuhi persyaratan standar JIS dan ISO. Campuran serat pulp RG dan bambu andong/betung dimasak dengan konsentrasi alkali 10,5% dan 12% untuk serat dari TKKS. Campuran perekat yang digunakan adalah tannin-resorsinol-formaldehida (TRF), alum (tawas) dan emulsi lilin. Campuran serat yang paling banyak memenuhi standar adalah RG pulp (50%) + TKKS pulp (50%), diikuti RG pulp (100%), TKKS pulp (50%) + pulp bambu andong (50%), RG pulp (50%) + pulp bambu betung (50%). Serat yang masih kurang prospektif (bambu betung) diharapkan dapat diperbaiki melalui penggunaan perekat TRF dalam jumlah lebih banyak, arang aktif berukuran nano dan cross-linking agent

Antihyperlipidemic and antiperoxidative effect of Diasulin, a polyherbal formulation in alloxan induced hyperglycemic rats

BACKGROUND: This study was undertaken to investigation the effect of Diasulin, a poly herbal drug composed of ethanolic extract of ten medicinal plants on blood glucose, plasma insulin, tissue lipid profile, and lipidperoxidation in alloxan induced diabetes. METHODS: Ethanolic extract of Diasulin a, poly herbal drug was administered orally (200 mg/kg body weight) for 30 days. The different doses of Diasulin on blood glucose and plasma insulin in diabetic rats were studied and the levels of lipid peroxides [TBARS, and Hydroperoxide] and tissue lipids [cholesterol, triglyceride, phospholipides and free fatty acids] were also estimated in alloxan induced diabetic rats. The effects were compared with glibenclamide. RESULT: Treatment with Diasulin and glibenclamide resulted in a significant reduction of blood glucose and increase in plasma insulin. Diasulin also resulted in a significant decrease in tissue lipids and lipid peroxide formation. The effect produced by Diasulin was comparable with that of glibenclamide. CONCLUSION: The decreased lipid peroxides and tissue lipids clearly showed the antihyperlipidemic and antiperoxidative effect of Diasulin apart from its antidiabetic effect