19 research outputs found

    Developmentof Hydrotalcite as an Adsorbent to Remove Heavy Metals in Lead and Chromium Solutions

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    This research work studies on the development of hydrotalcite mixed oxides as an adsorbent for the heavy metal removal application. The main objective of the study is to develop hydrotalcite mixed oxides which can adsorb optimum capacity of heavy metals ions. This is because of the increasing of heavy metals content in water, soil as well as food and also excess exposure to them can lead to damage in organism structure especially human beings and aquatic life. Based on previous researches, characteristics of hydrotalcite mixed oxides which are high surface area, porosity and basicity, are effectives for adsorption process. Hydrotalcite mixed oxides will be synthesized by using co-precipitation method and characterized to identify their composition, pore size, surface area and surface morphology using the equipment such as X-Ray Diffractometer (XRD), BET Surface Area Analyzer and Field Emission Scanning Electron Microscope (FESEM). After characterization, the hydrotalcites mixed oxides prepared will be tested for its efficiency in removing heavy metals suchas lead (Pb) and chromium (Cr) ions in aqueous solutions. The concentration of heavy metals left in the sample after adsorption process was measured by using Atomic Absorption Spectrometer (AAS) to identify the percentage of adsorption. Optimum adsorption capacity ofheavy metals is expected to be the result for this research

    Biology - Space Resources for Teachers

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    Aerospace biology curriculum for secondary schools including life support, physiological, and psychological aspects of manned space flight, and exobiolog

    Advanced physical characterisation of milled pharmaceutical solids

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    Milling has been the key unit operation in controlling particle size of pharmaceutical powders at scale. The work carried out in this thesis is a comprehensive study of the stability of pharmaceutical solids post-milling and upon storage, from molecular level up to bulk handling scale. It is an attempt to fill key gaps in knowledge with regard to the anomalous behaviour and physical instability of milled powder through the development of advanced novel techniques. The physical instability of milled or amorphous pharmaceutical powders often manifest in changes in derived powder properties. Moisture induced dimensional changes of amorphous lactose compacts were monitored by in-situ environmental controlled optical profilometry. The complex volumetric behaviour involves glassy-rubbery phase transition followed by amorphous-crystalline transformation under the influence of water. These associated changes were not observed in physical aging of amorphous lactose compacts by measuring specific surface area. At the molecular level these physical changes are governed by relaxation processes. By operating within the linear viscoelastic region, low strain uni-axial indentation of small molecule organic glasses at a range of temperature generated master curves using WLF analysis. Viscoelastic behaviour of these materials were determined to be controlled by local β-relaxation around the glass transition rather than globally for polymers. At the bulk level, due to the non-equilibrium nature of milled and amorphous powders, their surface energies tends to be significantly higher than the equivalent crystalline forms. This can be detrimental as highly cohesive and poor flowing powders are difficult to process. The unconfined compression test was adapted to measure cohesion of small weak pharmaceutical powder compacts. More significantly, a positive relationship was confirmed between surface energetics and cohesion of modified D-mannitol. At the particle level, the mechanism(s) by which milling or micronisation creates low levels of amorphicity remains unclear. MOUDI fractionation of bulk micronised α-lactose monohydrate and characterisation of fine fractions has clearly demonstrated that micronisation as well as mechanical particle size reduction also generates low levels of highly amorphous ultrafine particles within bulk crystalline powder which will have a significant effect on powder physical stability post-milling and upon storage. In conclusion, using the novel techniques developed here, significant progress has been towards understanding the physical behaviour of milled and amorphous pharmaceutical solids

    Scientific and Technical Publishing at Goddard Space Flight Center in Fiscal Year 1994

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    This publication is a compilation of scientific and technical material that was researched, written, prepared, and disseminated by the Center's scientists and engineers during FY94. It is presented in numerical order of the GSFC author's sponsoring technical directorate; i.e., Code 300 is the Office of Flight Assurance, Code 400 is the Flight Projects Directorate, Code 500 is the Mission Operations and Data Systems Directorate, Code 600 is the Space Sciences Directorate, Code 700 is the Engineering Directorate, Code 800 is the Suborbital Projects and Operations Directorate, and Code 900 is the Earth Sciences Directorate. The publication database contains publication or presentation title, author(s), document type, sponsor, and organizational code. This is the second annual compilation for the Center

    COBE's search for structure in the Big Bang

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    The launch of Cosmic Background Explorer (COBE) and the definition of Earth Observing System (EOS) are two of the major events at NASA-Goddard. The three experiments contained in COBE (Differential Microwave Radiometer (DMR), Far Infrared Absolute Spectrophotometer (FIRAS), and Diffuse Infrared Background Experiment (DIRBE)) are very important in measuring the big bang. DMR measures the isotropy of the cosmic background (direction of the radiation). FIRAS looks at the spectrum over the whole sky, searching for deviations, and DIRBE operates in the infrared part of the spectrum gathering evidence of the earliest galaxy formation. By special techniques, the radiation coming from the solar system will be distinguished from that of extragalactic origin. Unique graphics will be used to represent the temperature of the emitting material. A cosmic event will be modeled of such importance that it will affect cosmological theory for generations to come. EOS will monitor changes in the Earth's geophysics during a whole solar color cycle

    Study of the automated biological laboratory project definition. Volume VI - Technical appendices. Part 1 Final report, 10 Aug. 1964 - 10 Aug. 1965

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    Instrumental, chemical, and environmental techniques for detecting extraterrestrial life on Mars - automatic biological laboratory for Mars exploratio

    Development of a Micro-thermal Sensor Based on 3-omega Technique for Dynamic Freezing Applications

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    University of Minnesota Ph.D. dissertation. March 2019. Major: Mechanical Engineering. Advisor: John Bischof. 1 computer file (PDF); xvi, 153 pages.Atrial Fibrillation (AF) is a major heart disease affecting millions of people every year. If left untreated, AF can cause cardiovascular disease, stroke and even death. Cryoablation for PV (Pulmonary Vein) isolation has been used for more than 10 years in AF treatment, which involves freezing (< -60 0C) and subsequent scarring of PV using a cold balloon/ catheter surface. Despite widespread and growing clinical use, the precise dosing and treatment times for cryoablation can vary depending on cooling surface contact, tissue thickness, and freeze completion through the wall. Without this knowledge, the treatment can be expected to have diminishing efficacy and may contribute to collateral injury. For instance, under-freezing may lead to inadequate treatment, while over-freezing can damage adjacent tissues (esophagus, lung and nerves), thereby creating complications. Clearly, there is a need to monitor this process to ensure complete treatment while avoiding complications. Unfortunately, the approaches for monitoring cryotherapy in the treatment of other diseases using clinical imaging cannot work for PV due to poor spatial resolution (mm). Thus, there is a pressing need to improve monitoring of cryoablation of the PV to reproducibly supply information on freezing within tissues at the millimeter to sub-millimeter level. Here then we present a response to this need through development of a micro- thermal sensor based on the “3ω” technique. We propose that a disposable thermal sensor based on 3ω technology can be deployed on a balloon to measure tissue contact, thickness and the initiation and completion of freezing in the PV all with an accuracy better than 1 mm. The 3ω technique, on which the sensor is based, was originally developed for thin inorganic materials. The technique was first modified for measurement of thermal conductivity of soft, hydrated biological tissues. Using the new sensor, for the first time, we have measured the thermal conductivity of thin porcine cardiac tissues in vitro addressing a major knowledge gap to inform focal therapy modeling for atrial fibrillation. This information is critical for successful treatment planning/prediction of therapy impact in the PV and surrounding tissues. Next, we show a dynamic use of the sensor for monitoring an idealized therapy in in vitro thin tissues (≤ 2 mm). For this, we demonstrated the ability of the sensor (on a flat substrate) to sense contact, flow, tissue thickness and freeze front in idealized systems. Specifically, the sensor was used to sense contact with tissue vs. water, ice (frozen agargel) thickness, and freeze initiation and completion. The success of this study suggests that integration of “3ω” sensors onto cardiology probe surfaces (i.e. balloons or catheters) can monitor cryoablation and by extension other PV focal therapies. As a next step, we integrated these sensors onto cryoballoons using transfer printing techniques. The 3ω sensor technology has traditionally been used for flat and rigid substrates. Therefore, we modified the shape of the sensor from a linear to a serpentine shape for integration onto balloon substrates. Next, using numerical analyses, we investigated the ability of the modified sensor on a flat substrate to differentiate measurements in limiting cases of ice, water and fat. These numerical results were then complemented by experimentation by micro-patterning the serpentine sensor onto a flat substrate and onto a flexible balloon. In both formats (flat and balloon) the serpentine sensor was experimentally shown to: (1) identify tissue contact vs. fluid, (2) distinguish tissue thickness in the 0.5 to 2 mm range, and (3) measure the initiation and completion of freezing as previously reported for a linear sensor. This study demonstrates proof of principle that a serpentine 3ω sensor on a balloon can monitor tissue contact, thickness and phase change which is relevant for cryo and other focal thermal treatments of PV to treat atrial fibrillation

    Microgravity Science and Applications: Program Tasks and Bibliography for Fiscal Year 1996

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    NASA's Microgravity Science and Applications Division (MSAD) sponsors a program that expands the use of space as a laboratory for the study of important physical, chemical, and biochemical processes. The primary objective of the program is to broaden the value and capabilities of human presence in space by exploiting the unique characteristics of the space environment for research. However, since flight opportunities are rare and flight research development is expensive, a vigorous ground-based research program, from which only the best experiments evolve, is critical to the continuing strength of the program. The microgravity environment affords unique characteristics that allow the investigation of phenomena and processes that are difficult or impossible to study an Earth. The ability to control gravitational effects such as buoyancy driven convection, sedimentation, and hydrostatic pressures make it possible to isolate phenomena and make measurements that have significantly greater accuracy than can be achieved in normal gravity. Space flight gives scientists the opportunity to study the fundamental states of physical matter-solids, liquids and gasses-and the forces that affect those states. Because the orbital environment allows the treatment of gravity as a variable, research in microgravity leads to a greater fundamental understanding of the influence of gravity on the world around us. With appropriate emphasis, the results of space experiments lead to both knowledge and technological advances that have direct applications on Earth. Microgravity research also provides the practical knowledge essential to the development of future space systems. The Office of Life and Microgravity Sciences and Applications (OLMSA) is responsible for planning and executing research stimulated by the Agency's broad scientific goals. OLMSA's Microgravity Science and Applications Division (MSAD) is responsible for guiding and focusing a comprehensive program, and currently manages its research and development tasks through five major scientific areas: biotechnology, combustion science, fluid physics, fundamental physics, and materials science. FY 1996 was an important year for MSAD. NASA continued to build a solid research community for the coming space station era. During FY 1996, the NASA Microgravity Research Program continued investigations selected from the 1994 combustion science, fluid physics, and materials science NRAS. MSAD also released a NASA Research Announcement in microgravity biotechnology, with more than 130 proposals received in response. Selection of research for funding is expected in early 1997. The principal investigators chosen from these NRAs will form the core of the MSAD research program at the beginning of the space station era. The third United States Microgravity Payload (USMP-3) and the Life and Microgravity Spacelab (LMS) missions yielded a wealth of microgravity data in FY 1996. The USMP-3 mission included a fluids facility and three solidification furnaces, each designed to examine a different type of crystal growth
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