Karakteristik Pembakaran Dan Sifat Fisik Briket Ampas Empulur Sagu Untuk Berbagai Bentuk Dan Prosentase Perekat

Fossil fuel reserves are depleting to be anticipated by looking for alternative energy sources. Alternative energy that many developed and researched today is agricultural waste biomass fuel is formed into briquettes. In this research, briquettes are made from dregs the pith of sago in the four of form, namely : cylinders, blocks, cubes and prisms, with and without adhesive sago starch with the presentation of 5% and 10%.This research aimed to determine the effect form briquettes on the combustion rate and determine the physical properties of briquettes without carbonization process, with or without the addition of sago starch as an adhesive which include moisture content, ash content, volatile matter, fixed carbon and heating value.The results research that the form of briquettes affects the combustion rate where the fastest combustion speed was on briquettes form beams, cube and Prism. Percentage adhesive of sago starch affects the early combustion time where time is needed to ignite the briquettes greatest for percentage 10% and the lowest adhesive for briquettes without adhesives. Adhesive sago starch is also very influential on the moisture content, ash content, volatile substances, fixed carbon and heating value. Adhesive sago starch is also very influential on the moisture content, ash content, volatile matter, fixed carbon and heating value. The addition of adhesive sago starch lower heating value

PERUBAHAN MAKNA RUANG BERDASARKAN BUDAYA CATUSPATHA DESA PAKRAMAN UBUD, KABUPATEN GIANYAR

Secara harfiah, catuspatha memiliki nilai ystem, fungsi dan makna tersendiri. Dalam konteks kebudayaan bali, catuspatha sebagai pusat kerajaan yang mengandung empat elemen pembentuk yang disesuaikan desa, kala, patra pada masing-masing wilayah. Sedangkan, dalam konteks agama hindu, catuspatha terbentuk berdasarkan ystem swastika yang diibaratkan dengan ystem kebahagiaan. Dengan adanya perubahan ystem, tidak menuntut kemungkinan bahwa pada era ini, catuspatha mengalami perubahan fungsi catuspatha. Selain kental akan nilai sejarahnya, ruang tengah pada catuspatha Desa Pakraman Ubud masih tampak kosong tanpa penambahan elemen estetika serta Puri Saren Ubud yang berada pada lokasi penelitian. Tujuan dari penelitian ini adalah untuk menjelaskan makna yang tertuang dalam catuspatha, dimana perubahan-perubahan yang terjadi terhadap elemen-elemen pembentuk catuspatha menjadi acuan dasar dalam menjelaskan makna yang tertuang dalam catuspatha. Untuk mencapai tujuan tersebut, dilakukan dengan melakukan observasi, wawancara analisis di lapangan, wawancara terkait catuspatha serta pembentuk elemen catuspatha serta narasumber yang berperan penting dalam mengetahui pembentukan catuspatha, serta dilakukan pula cross check berdasarkan literatur dan hasil penelitian. Hasil yang diperoleh dari penelitian ini adalah terjadinya perubahan ystem serta adanya perubahan berupa gagasan dan pandangan terkait catuspatha sebagai simpang empat yang mengandung makna simbolik adanya kegiatan adat, ekonomi dan ystem; makna filosofis, simpang empat menyiratkan palang atau suatu tapak dara; dan makna kesakralan, nilai ystem dalam catuspatha diambil melalui pembangunan catuspatha dengan proses pensakralan melalui ritual keagamaan dan pemasupatian

Relationship between birth weight and retinal microvasculature in newborn infants

Objective: The purposes of this study were to determine the normal retinal microvasculature measurements in human infants who are born at term and to determine whether birth weight influences measurements of retinal microvasculature. Study Design: Retinal arteriole and venule measurements were obtained in a cohort of 24 infants who were born at term. Digital images of both the retinas were obtained using a digital retinal camera after pupillary dilation. Result: In all, 24 newborn infants born at term (12 females and 12 males) were analyzed in this study. The measured retinal arteriole diameters were from 66.8 to 147.8 μm (mean, 94.2±19.6 μm), and the venule diameters were from 102.0 to 167.8 μm (mean, 135.2±19.1 μm). Seven babies in the sample had low birth weight (LBW), while 17 babies were born with normal weight. Babies with lower birth weights had larger arteriole (113.1±17.9 μm vs 86.4±14.4 μm; P=0.0009) and venule diameters (151.7±14.9 μm vs 128.4±16.9 μm; P=0.0040). Conclusion: Retinal venules and arterioles in LBW babies are larger compared with those of normal-birth-weight babies. We postulate that the difference observed in our study was due to in utero pathophysiological changes that occurred in the cerebral circulation of growth-restricted fetuses

On The Rate and Extent of Drug Delivery to the Brain

To define and differentiate relevant aspects of blood–brain barrier transport and distribution in order to aid research methodology in brain drug delivery. Pharmacokinetic parameters relative to the rate and extent of brain drug delivery are described and illustrated with relevant data, with special emphasis on the unbound, pharmacologically active drug molecule. Drug delivery to the brain can be comprehensively described using three parameters: Kp,uu (concentration ratio of unbound drug in brain to blood), CLin (permeability clearance into the brain), and Vu,brain (intra-brain distribution). The permeability of the blood–brain barrier is less relevant to drug action within the CNS than the extent of drug delivery, as most drugs are administered on a continuous (repeated) basis. Kp,uu can differ between CNS-active drugs by a factor of up to 150-fold. This range is much smaller than that for log BB ratios (Kp), which can differ by up to at least 2,000-fold, or for BBB permeabilities, which span an even larger range (up to at least 20,000-fold difference). Methods that measure the three parameters Kp,uu, CLin, and Vu,brain can give clinically valuable estimates of brain drug delivery in early drug discovery programmes

Role of Small Addition of Liquefied Petroleum Gas (LPG) on Laminar Burning Velocity of Hydrous Ethanol

Ethanol is an appropriate substitution for gasoline fuel in spark ignition engines. Ethanol has a high-octane number allowing to use it in the higher compression ratio of the engine. A better understanding of combustion characteristics of ethanol is needed before it is used widely in the spark ignition engine. One of the most important parameters of the replacement fuel is the burning velocity. Therefore, the purpose of the research is to investigate experimentally the effect of the small addition of liquefied petroleum gas (LPG) on the laminar burning velocity of hydrous ethanol. The combustion characteristic of the ethanol and LPG mixture was examined in a cylindrical combustion chamber with a diameter of 10.8 cm and a length of 17 cm. The flame had a spherically expanding shape. Fuel mixture was ignited by sparks inside the cylinder and the flame diameter was measured from the flame image captured by the high-speed camera. The research used two types of ethanol fuel such as anhydrous ethanol and hydrous ethanol containing 0.3 % of water. The percentage of LPG in the fuel mixture was varied from 0 % to 20 %. The results showed that the addition of 10 % LPG in ethanol increases laminar burning velocity. For anhydrous fuels, ethanol burning velocity is higher than for LPG and the highest burning velocity is in ethanol, to which 10 % LPG is added while the lowest is in LPG. Besides, the effect of water content in ethanol fuel causes a decrease in combustion speed significantly. But the addition of LPG up to 10 % makes hydrous ethanol relatively more robust to rising water content due to the combustion reaction is helped by a higher radical concentration in LPG. This is caused by two factors: the partial preheating zone resulted by the hydroxyl group (OH) of ethanol that supplied more heat energy and the high concentration of radicals in LPG that assists the combustion reaction

Development of Planar Meso­scale Combustor with Double Narrow Slit Flame Holder and Various Aspect Ratios for Micropower Generator

We have investigated the effects of the aspect ratio of the rectangular mesoscale combustor with a narrow slit flame holder on the flame stability limit, flame behavior and uniformity of combustor wall temperature. The combustor was made of copper with a cross-section area of 6 mm2. The combustor aspect ratio (AR) was varied as 1, 1.5, 2.67, and 6. LPG and pure oxygen were premixed and the experiment was conducted at a limited flow rate. Pure oxygen is selected as an oxidizing agent with the intention of revealing in detail the range of flame stability within a very narrow quenching distance. All observed flames were inside the combustion chamber, not outside the channel. This research used a new type of flame holder namely double narrow slit flame holder as a flame stabilizer. The flame holder with double slit and a kind of bluff body in the center helps recirculate the flow and prolong the residence time to make the flame more stable. The use of double narrow slit flame holder successfully extended the stability map to a very lean equivalence ratio (f). However, there was a dead zone near stoichiometry condition due to very high flame propagation speed. Aspect ratio had an important role for the non-circular combustor. The aspect ratio gave a great effect to determine the limit of the stability map that can be achieved at the rich mixture. The combustor with AR=1.5 had the widest range of flammability limit, while AR=6 hadthe narrowestflame stability limits. However, the latter reached the most uniform wall temperature, which is important to obtain high efficiency thermal to electric energy conversion. The results of this study can be used to determine the right fuel mixture on the mesoscale combustor as a heat source on the micro power generator/thermal electric syste

Effect of Backward Facing Step on Combustion Stability in a Constant Contact Area Cylindrical Meso­scale Combustor

This experiment investigates the effect of backward facing step size variation on combustion stability in the cylindrical meso-scale combustor with the constant contact area. The backward facing step was varied by changing the combustor inlet diameter while the combustor diameter at the combustion zone was kept constant, i.e. has a constant contact area. Butane gas (C4H10) was used as fuel with air as an oxidizing agent. The result shows that the backward facing step has an important role in the combustion stabilization mechanism. Stable flame could be stabilized inside the meso-scale combustor with the backward facing step. Without the backward facing step, the flame blows out, then stable at the combustor rim. Recirculation flow occurs in the area behind the backward facing step. The increasing backward facing step size leads to an increase in reactant inlet velocity, recirculation flow size and shear stress in the area near the backward facing step. At large backward facing step size, the high reactant inlet velocity together with the large shear stress quenches the flame while the heat recovered by recirculation flow is less sufficient to stabilize flame so that the flame drifts to the downstream position. Hence bigger backward facing step size causes narrower flame stability limit area. The smaller the backward facing step size the wider the flame stability limit which shifts more toward lower equivalence ratio and high reactant velocity regions. Decreasing the backward facing step size decreases the reactant velocity into the combustion reaction zone as well as decreases the recirculation flow and the shear stress, so that the quenching effect decreases. The smaller recirculation flow has a better function for the flame holder to increase flame stability inside the meso-scale combustor. Therefore, small backward facing step size has a very important role in recovering heat energy stabilizing the flame in the meso-scale combusto