Real Work

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Writing Sample

When Hearts Grapple, excerpt

Hybrid Rice: Economic Assessment of a Promising Technology for Sustainable Food Grain Production in Bangladesh

Hybrid rice, one of the viable and proven technologies has been considered as a new frontier to increase rice production for meeting growing demand for staple food in Bangladesh. Using farm survey data this paper examines comparative profitability of hybrid and inbred rice cultivation and estimates a Stochastic Frontier Function to determine the effect of key variables on farm efficiency. Results show that hybrid rice gives substantially higher yield as well as net return compared to inbred rice which leads to increase and sustainable growth of food grain production. Analysis of Stochastic Frontier model shows hybrid rice farms are technically more efficient than inbred.Hybrid Rice, Technology, Economics, Food Self-sufficiency, Crop Production/Industries, International Development, Research and Development/Tech Change/Emerging Technologies,

“An Analysis of the Use of Past Simple and Present Perfect in the English Translation of ‘Broken April’”

Translation is a kind of activity which inevitably involves at least two languages and two cultural traditions. Languages contain dialects with various cultural expressions. Ismail Kadare has created a great treasure of dialects from various parts of Albania. Dialects are important sources of words and their vocabulary is important for the understanding of the origin of certain words. The Albanian version of Broken April is a perfect reflection of the Gheg dialect spoken in the Northern part of Albania. According to Guynes (2012), ‘Kadare contradictorily provides readers with an image of the Kanun as both an outdated set of laws averse to modernism and a tradition as vital to the Albanians as the lifestyle of the highlanders and the national myth of the urbanites (p.7) The aim of this research is to clarify the uncertainty of the use of the past simple and present perfect tense in the Albanian English translation. The aim of this research is to find out if the dominance of Geg dialect in the dialogues of ‘Prilli i thyer’ has any impact on the use of present perfect or past simple in the English translation. It also aims to observe if the change of present perfect from ‘Prilli i thyer’ into past tense or vice versa in the English translation ‘Broken April’, carry the same meaning from the source text to the target text

Technique for Configuring an Actively Cooled Thermal Shield in a Flight System

Broad area cooling shields are a mass-efficient alternative to conductively cooled thermal radiation shielding. The shield would actively intercept a large portion of incident thermal radiation and transport the heat away using cryogenic helium gas. The design concept consists of a conductive and conformable surface that maximizes heat transfer and formability. Broad Area Cooled (BAC) shields could potentially provide considerable mass savings for spaceflight applications by eliminating the need for a rigid thermal radiation shield for cryogen tanks. The BAC consists of a network of capillary tubes that are thermally connected to a conductive shield material. Chilled helium gas is circulated through the network and transports unwanted heat away from the cryogen tanks. The cryogenic helium gas is pumped and chilled simultaneously using a specialized pulse-tube cryocooler, which further improves the mass efficiency of the system. By reducing the thermal environment temperature from 300 to 100 K, the radiative heat load on a cryogen tank could be reduced by an order of magnitude. For a cryogenic liquid propellant scenario of oxygen and hydrogen, the boiloff of hydrogen would be significantly reduced and completely eliminated for oxygen. A major challenge in implementing this technology on large tanks is that the BAC system must be easily scalable from lab demonstrations to full-scale missions. Also, the BAC shield must be conformable to complex shapes like spheres without losing the ability to maintain constant temperature throughout. The initial design maximizes thermal conductivity between the capillary tube and the conductive radiation shielding by using thin, corrugated aluminum foil with the tube running transverse to the folds. This configuration has the added benefit of enabling the foil to stretch and contract longitudinally. This allows the BAC to conform to the complex curvature of a cryogen tank, which is key to its success. To demonstrate a BAC shield system with minimal impact to current cryogen tank designs, the shielding must be applied after the final assembly of the tank and supporting structure. One method is to pre-fabricate the shield in long strips. A spool of corrugated aluminum foil with a thermally sunk aluminum capillary running through the center could then be simply wound around the cryogen tanks and encapsulated within the multi-layer insulation (MLI) blanket. Then, on orbit, the BAC would intercept thermal radiation coming in through the MLI and transport it away from the cryogen tanks. An optimization of the design could be done to take into account mass savings from thinner MLI blankets, eliminating solid thermal shields, and ultimately, a reduction in the required cryogen tank size

Cryogenic Hydrogen Oxygen Propulsion System for Planetary Science Missions

A Cryogenic Hydrogen Oxygen Propulsion System (CHOPS) that uses liquid hydrogen (LH2) and liquid oxygen (LO2) propellants can dramatically enhance NASA's ability to explore the solar system due to their superior specific impulse (Isp) capability. Although these cryogenic propellants can be challenging to manage and store, they allow significant mass advantages over traditional hypergolic propulsion systems and are therefore enabling for many planetary science missions. New cryogenic storage techniques such as subcooling, advanced insulation, low thermal conductivity structures allow for the long term storage and use of cryogenic propellants for solar system exploration and hence allow NASA to deliver more payloads to targets of interest, launch on smaller and less expensive launch vehicles, or both

Active Costorage of Cryogenic Propellants for Exploration

Long-term storage of cryogenic propellants is a critical requirement for NASA's effort to return to the moon. Liquid hydrogen and liquid oxygen provide the highest specific impulse of any practical chemical propulsion system, and thus provides the greatest payload mass per unit of launch mass. Future manned missions will require vehicles with the flexibility to remain in orbit for months, necessitating long-term storage of these cryogenic liquids. For decades cryogenic scientific satellites have used cryogens to cool instruments. In many cases, the lifetime of the primary cryogen tank has been extended by intercepting much of the heat incident on the tank at an intermediate-temperature shield cooled either by a second cryogen tank or a mechanical cryocooler. For an LH2/LO2 propellant system, a combination of these ideas can be used, in which the shield around the LO2 tank is attached to, and at the same temperature as, the LO2 tank, but is actively cooled so as to remove all heat impinging on the tank and shield. This configuration eliminates liquid oxygen boil-off and cuts the liquid hydrogen boil-off to a small fraction of the unshielded rate. This paper studies the concept of active costorage as a means of long-term cryogenic propellant storage. The paper describes the design impact of an active costorage system for the Crew Exploration Vehicle (CEV). This paper also compares the spacecraft level impact of the active costorage concept with a passive storage option in relation to two different scales of spacecraft that will be used for the lunar exploration effort, the CEV and the Earth Departure Stage (EDS). Spacecraft level studies are performed to investigate the impact of scaling of the costorage technologies for the different components of the Lunar Architecture and for different mission durations