An experimental study of the dual-fuel performance of a small compression ignition diesel engine operating with three gaseous fuels

A dual-fuel engine is a compression ignition (CI) engine where the primary gaseous fuel source is premixed with air as it enters the combustion chamber. This homogenous mixture is ignited by a small quantity of diesel, the ‘pilot’, that is injected towards the end of the compression stroke. In the present study, a direct-injection CI engine, was fuelled with three different gaseous fuels: methane, propane, and butane. The engine performance at various gaseous concentrations was recorded at 1500 r/min and quarter, half, and three-quarters relative to full a load of 18.7 kW. In order to investigate the combustion performance, a novel three-zone heat release rate analysis was applied to the data. The resulting heat release rate data are used to aid understanding of the performance characteristics of the engine in dual-fuel mode. Data are presented for the heat release rates, effects of engine load and speed, brake specific energy consumption of the engine, and combustion phasing of the three different primary gaseous fuels. Methane permitted the maximum energy substitution, relative to diesel, and yielded the most significant reductions in CO2. However, propane also had significant reductions in CO2 but had an increased diffusional combustion stage which may lend itself to the modern high-speed direct-injection engine

Perancangan Prototype Pembangkit Listrik Tenaga Gelombang Laut Tipe Oscilating Water Column Di Pantai Bandealit Jember

Pemanfaatan gelombang laut sebagai pembangkit listrik merupakan langkah yang bagus untuk meminimalisir penggunaan bahan bakar fosil sebagai bahan bakar pembangkit listrik konvensional. Oscilating Water Column merupakan salah satu cara yang dapat digunakan sebagai media pembangkit listrik tenaga gelombang laut tersebut. Gerakan naik turun dari gelombang laut pada kolom udara yang akan menekan udara sehingga dapat menekan turbin untuk melakukan putaran , dengan poros turbin yang menjadi satu dengan turbin maka turbin akan ikut berputar sehingga menghasilkan daya listrik. Pembuatan prototype Oscilting Water Column dengan perbandingan skala 1: 4 dengan dimensi prototype panjang, lebar dan tinggi masing – masing 1 m.Ketinggian gelombang yang dibangkitkan di laboratorium dengan ketinggian 0,2 meter dan 0,23 meter memiliki daya keluaran rata – rata sebesar 4,8 dan 8,27 mWatt dengan perbandingan perhitungan matematis dengan tinggi gelombang yang sama mampu menghasilkan daya keluaran rata – rata sebesar 8,1 watt dan 13,2 watt

Review of aquaculture and fish consumption in Bangladesh

Fish play a crucial role in the Bangladeshi diet, providing more than 60% of animal source food, representing a crucial source of micro-nutrients, and possessing an extremely strong cultural attachment. Fish (including shrimp and prawn) is the second most valuable agricultural crop, and its production contributes to the livelihoods and employment of millions. The culture and consumption of fish therefore has important implications for national food and nutrition security, poverty and growth. This review examines the current state of knowledge on the aquaculture sector and fish consumption in Bangladesh, based on extensive analysis of secondary sources (including unpublished data unavailable elsewhere), consultation with various experts and specially conducted surveys. The review is comprised of three sections. Section 1 describes the main systems of aquaculture production in terms of their technical and social characteristics and outputs. Section 2 addresses issues relating to seed and feed. The final section analyses fish consumption patterns and demand, and attempts to estimate the volumes of fish produced from a range of sources.Food fish, Aquaculture, Food consumption, Fish consumption, Pond culture, Rice field aquaculture, Bangladesh,

Optical properties of diamond like carbon films prepared by DC-PECVD

Diamond-like carbon (DLC) thin films were deposited at different substrate temperatures using methane and hydrogen gas in DC-PECVD at 2x10-1Torr. From the light transmission using UV-VIS spectroscopy it was found that the optical transition had changed from allowed indirect transition to allowed direct transition as the substrate temperature increased. The Optical gap increased with temperature, highest of 3.034 eV was observed at 573 K, beyond which it dropped. Colour of the film changed from light brownish to a colourless transparent film in the higher temperature. The Urbach energy decreased from 1.25 eV to 0.75 eV with increasing substrate temperature till 573 K and a slight increase after it. This trend is attributed to change in sp3/sp2 ratio or change in structure. The cluster size decreases with temperature, resulting in larger band gap and the structure more ordered. Similar pattern is also witnessed in the emission spectrum of the photoluminescence

Magnetic response of core-shell cobalt ferrite nanoparticles at low temperature

Cobaltferritenanoparticles (size: 26±4nm) have been synthesized by coprecipitation route. The coercivity of nanoparticles follows a simple model of thermal activation of particle moments over the anisotropy barrier in the temperature range of 30–300K in accordance with Kneller’s law; however, at low temperatures

The effect of queue size on the throughput, in group failure mode, for the loaded transport channel

The external data flow decreases the throughput of the transport connection. The indicator of this external load is the queue size in front of the protocol data. In this article, using a mathematical model in analytical and numerical forms, the relation between the throughput of the channel and the protocol parameters are presented including the queue size parameter. In this work the effect of the queue size on time-out duration has been shown, which is one of the important parameters and it's studied weakly in researches. Also, the relation between round-trip delay, the reliability of the transmission of the information segments with queue size are also shown

Sub-millimeter galaxies as progenitors of compact quiescent galaxies

Three billion years after the big bang (at redshift z=2), half of the most massive galaxies were already old, quiescent systems with little to no residual star formation and extremely compact with stellar mass densities at least an order of magnitude larger than in low redshift ellipticals, their descendants. Little is known about how they formed, but their evolved, dense stellar populations suggest formation within intense, compact starbursts 1-2 Gyr earlier (at 3<z<6). Simulations show that gas-rich major mergers can give rise to such starbursts which produce dense remnants. Sub-millimeter selected galaxies (SMGs) are prime examples of intense, gas-rich, starbursts. With a new, representative spectroscopic sample of compact quiescent galaxies at z=2 and a statistically well-understood sample of SMGs, we show that z=3-6 SMGs are consistent with being the progenitors of z=2 quiescent galaxies, matching their formation redshifts and their distributions of sizes, stellar masses and internal velocities. Assuming an evolutionary connection, their space densities also match if the mean duty cycle of SMG starbursts is 42 (+40/-29) Myr (consistent with independent estimates), which indicates that the bulk of stars in these massive galaxies were formed in a major, early surge of star-formation. These results suggests a coherent picture of the formation history of the most massive galaxies in the universe, from their initial burst of violent star-formation through their appearance as high stellar-density galaxy cores and to their ultimate fate as giant ellipticals.Comment: ApJ (in press

Pemanfaatan Keanekaragaman Genetik Tumbuhan Oleh Masyarakat Tugutil Di Sekitar Taman Nasional Aketajawe Lolobata (Utilization of Plant Genetic Biodiversity by Tugutil Tribe in Aketajawe Lolobata National Park)

Indonesia is one of the richnest country in biodiversity, including the higest of diversity of agriculture genetic resources. Tugutil society is one ethnic in halmahera which have well knowledges in used of genetic resouces. Indigenous knowledges on genetic resources of agriculture by tugutil in Wasile, Halmahera is presented. 149 sources of They have been used 149 agricultural and medicinal genetic resources. There are 100 genetic resources of agriculture crop (71 species) they used for sources of primary food, secondary food like fruit, vegetables, etc.) and 49 plant medicinal genetic resources (45 species). Tugutil society has knowledge about how they wise used the genetic resources like not over exploited, local wisdom to conservation their genetic resources from destruction

Pro-poor intervention strategies in irrigated agriculture in Asia: poverty in irrigated agriculture: issues and options: Bangladesh

Irrigated farming / Poverty / Irrigation management / Water resource management / Policy / Planning / Institutions / Organizations / Local government / Non-governmental organizations / Legislation / Water users / Participatory management / Public sector / Water allocation / Cost recovery / Households / Income / Expenditure / Irrigation canals / Bangladesh