The Acquisition of Knowledge (A discussion in dialogue form)

Setting for the dialogue: Mantu meets Nisha in the realms of eternity where in all knowledge and truth make themselves manifest and discuss the philosophical questions of truth and knowledge. Mantu starts the dialogue on the question of What is knowledge? and after some length of discussion they arrive at an understanding of its parts

Radiological assessment for Space Station Freedom

Circumstances have made it necessary to reassess the risks to Space Station Freedom crewmembers that arise from exposure to the space radiation environment. An option is being considered to place it in an orbit similar to that of the Russian Mir space station. This means it would be in a 51.6 deg inclination orbit instead of the previously planned 28.5 deg inclination orbit. A broad range of altitudes is still being considered, although the baseline is a 407 km orbit. In addition, recent data from the Japanese A-bomb survivors has made it necessary for NASA to have the exposure limits reviewed. Preliminary findings of the National Council on Radiation Protection and Measurements indicate that the limits must be significantly reduced. Finally, the Space Station will be a laboratory where effects of long-term zero gravity on human physiology will be studied in detail. It is possible that a few crewmembers will be assigned to as many as three 1-year missions. Thus, their accumulated exposure will exceed 1,000 days. Results of this radiation risk assessment for Space Station Freedom crewmembers finds that females less than 35 years old will be confined to mission assignments where the altitude is less than about 400 km. Slight restrictions may also need to be made for male crewmembers less than 35 years old

The effects of female labor force participation on obesity

This paper assesses whether a causal relationship exists between recent increases in female labor force participation and the increased prevalence of obesity amongst women. The expansions of the Earned Income Tax Credit (EITC) in the 1980s and 1990s have been established by prior literature as having generated variation in female labor supply, particularly amongst single mothers. Here, we use this plausibly exogenous variation in female labor supply to identify the effect of labor force participation on obesity status. We use data from the National Health Interview Survey (NHIS) and replicate labor supply effects of the EITC expansions found in previous literature. This validates employing a difference-in-differences estimation strategy in the NHIS data, as has been done in several other data sets. Depending on the specification, we find that increased labor force participation can account for at most 19% of the observed change in obesity prevalence over our sample period. Our preferred specification, however, suggests that there is no causal link between increased female labor force participation and increased obesity.Women - Employment ; Obesity ; Tax credits

The Effects of Female Labor Force Participation on Obesity

This paper assesses whether a causal relationship exists between recent increases in female labor force participation and the increased prevalence of obesity amongst women. The expansions of the Earned Income Tax Credit (EITC) in the 1980s and 1990s have been established by prior literature as having generated variation in female labor supply, particularly amongst single mothers. Here, we use this plausibly exogenous variation in female labor supply to identify the effect of labor force participation on obesity status. We use data from the National Health Interview Survey (NHIS) and replicate labor supply effects of the EITC expansions found in previous literature. This validates employing a difference-in-differences estimation strategy in the NHIS data, as has been done in several other data sets. Depending on the specification, we find that increased labor force participation can account for at most 19% of the observed change in obesity prevalence over our sample period. Our preferred specification, however, suggests that there is no causal link between increased female labor force participation and increased obesity.female labor force participation, obesity, earned income tax credit

Analyses of risks associated with radiation exposure from past major solar particle events

Radiation exposures and cancer induction/mortality risks were investigated for several major solar particle events (SPE's). The SPE's included are: February 1956, November 1960, August 1972, October 1989, and the September, August, and October 1989 events combined. The three 1989 events were treated as one since all three could affect a single lunar or Mars mission. A baryon transport code was used to propagate particles through aluminum and tissue shield materials. A free space environment was utilized for all calculations. Results show the 30-day blood forming organs (BFO) limit of 25 rem was surpassed by all five events using 10 g/sq cm of shielding. The BFO limit is based on a depth dose of 5 cm of tissue, while a more detailed shield distribution of the BFO's was utilized. A comparison between the 5 cm depth dose and the dose found using the BFO shield distribution shows that the 5 cm depth value slightly higher than the BFO dose. The annual limit of 50 rem was exceeded by the August 1972, October 1989, and the three combined 1989 events with 5 g/sq cm of shielding. Cancer mortality risks ranged from 1.5 to 17 percent at 1 g/sq cm and 0.5 to 1.1 percent behind 10 g/sq cm of shielding for five events. These ranges correspond to those for a 45 year old male. It is shown that secondary particles comprise about 1/3 of the total risk at 10 g/sq cm of shielding. Utilizing a computerized Space Shuttle shielding model to represent a typical spacecraft configuration in free space at the August 1972 SPE, average crew doses exceeded the BFO dose limit

The Effect Of 3d Printing Machine Parameters In Extrusion Process Of Biocomposite Materials (Pmma And Ha) On Dimensional Accuracy

Bone implants are medical procedures involving replacement or reconstruction of missing or damaged bones with the patient's ones, natural substitutes or artificial substitutes. The widely used bone cement is a polymethylmethacrylate (PMMA) based composite material. To improve bioactivity, PMMA is combined with hydroxyapatite (HA). The manual formation can make bone implants during surgery. However, the method requires a longer operation time and raises the possibility of a higher error. Therefore, 3D printing technology is used to improve the quality of bone implants. One of the machines that can be used is the 3D printing machine, the property of the Product Design and Development Laboratory of Universitas Gadjah Mada. This machine needs to be tested to determine the accuracy of the prints, which is one indicator of product quality. Several machine parameters can be set in this machine setting. This study aims to determine the effect of three parameters, those are perimeter speed or edge print speed (20-40 mm / s), infill speed or inner print speed (50 - 70 mm / s), and fill angle or inner slope of inner printing (45 - 90 ° C). Before printing complex shapes, the machine was tested in advance with a more straightforward specimen design, which is a specimen design of flexural strength test. Response surface experiment design is used to determine the effect of three parameters on the dimensional accuracy which is measured through dimensional error. The results show that these three factors have no significant impact on the dimensional error, but the resulting error is still high. Therefore, it is necessary to adjust the design size before printing

An SEM study of the nuchal organ in Daphnia himalaya (nov. sp.) embryos and neonates collected from the Khumbu region (Nepalese Himalayas)

Zooplankton from the Khumbu region in Nepal are rarely studied, and little is known regarding their morphology and physiology. During the EV-K2-CNR Project, a collaboration between the Government of the Republic of Italy and the Nepal Academy of Science and Technology (NAST) as part of "The long distance transport of micro-pollutants", zooplankton samples revealed the presence of small head shields\u27 remains in the sediment possessing a hole in the dorsal margin. This observation led to the hypothesis that Daphnia himalaya neonates must possess a nuchal organ for osmoregulation in these alpine lakes. Here we report the presence of a nuchal organ in embryos and neonates, and explore its development, noting that the nuchal organ is retained up until the first post-embryonic moult. We also examine the chemistry of the lakes and in particular their conductivity, which is lower in lakes having D. himalaya than in lakes that do not (16 ?S and 32 ?S cm-1 respectively)

Applying Lean Maintenance to Optimize Manufacturing Processes in the Supply Chain: A Peruvian Print Company Case

High competitiveness forces companies to reduce their costs and optimize their processes throughout their supply chain. One of these supply chain processes is manufacturing, where the objective may be that the machines work at their maximum efficiency and capacity. This research proposes to increase the effectiveness of the printing process by improving the maintenance applying the Lean concepts. The research will serve as a guide for other companies in the printing industry that seek to increase their production based on the effectiveness of their equipment focused on maintenance processes, which is an important component in their supply chain manufacturing