Micro-Sigmoids as Progenitors of Coronal Jets - Is Eruptive Activity Self-Similarly Multi-Scaled?

Observations from the X-ray telescope (XRT) on Hinode are used to study the nature of X-ray bright points, sources of coronal jets. Several jet events in the coronal holes are found to erupt from small-scale, S-shaped bright regions. This finding suggests that coronal micro-sigmoids may well be progenitors of coronal jets. Moreover, the presence of these structures may explain numerous observed characteristics of jets such as helical structures, apparent transverse motions, and shapes. In analogy to large-scale sigmoids giving rise to coronal mass ejections (CMEs), a promising future task would perhaps be to investigate whether solar eruptive activity, from coronal jets to CMEs, is self-similar in terms of properties and instability mechanisms.Comment: 8 pages, 5 figures, 1 tabl

What Is a Modern Meat-Type Hog?

The concept of a meat-type hog today is different than it was 10 years ago. Carcass qualities are improving right along. But there\u27s still room for improving both the hogs and the methods for paying for them

What Is a Meat-Type Steer?

The ideal meat-type beef animal is between (1) our current standards that result in some carcasses with excess fat and (2) an animal that produces a carcass of only lean meat - with no fat and no marbling

A Look at Dual Beef Grading

Dual grading of beef carcasses concerns both quality and amount fo edible meat. The system is aimed to result in slaughter cattle prices that encourage the production of meat-type carcasses. Here\u27s what it\u27s all about

BENEFICIAL REUSE OF LOCALLY-AVAILABLE WASTE MATERIALS AS LIGHTWEIGHT AGGREGATE IN LIGHTWEIGHT CONCRETE

This study investigated the physical characteristics of lightweight concrete produced using waste materials as coarse aggregate. The study was inspired by the author’s Peace Corps service in Kilwa, Tanzania. Coconut shell, sisal fiber, and PET plastic were chosen as the test waste products due to their abundance in the area. Two mixes were produced for each waste product and the mix proportions designed for resulting compressive strengths of 3000 and 5000 psi. The proportions were selected based on guidelines for lightweight concrete from the American Concrete Institute. In preparation for mixing, coconut shells were crushed into aggregate no larger than 3/4 inch, sisal fiber was cut into pieces no longer than 3/8 inch, and PET plastic was shredded into 1/4 inch-wide strips no longer than 6 inches. Replicate samples were mixed and then cured for 28 days before they were tested for compressive strength, unit weight, and absorption. The resulting data were compared to ASTM Standards for lightweight concrete masonry units to determine their adequacy. Based on these results, there is potential for coconut shell to be used as coarse aggregate in lightweight concrete. Sisal fiber was unsuccessful in producing the appropriate compressive strength. However, the reduction in spalling of the hardened concrete and the induction of air in the mixes incorporating sisal fiber suggests that it has the potential to improve other characteristics of lightweight concrete. Concrete mixes using PET plastic as aggregate resulted in adequate compressive strengths, but were too dense to be considered ‘lightweight’ concrete. With some adjustments to slightly decrease absorption and unit weight, the PET plastic concrete mixes could be classified as medium weight concrete and, therefore, achieve many of the same benefits as would be seen with lightweight concrete

PRODUCTION OF LOW-ENERGY, 100% BY-PRODUCT CEMENT UTILIZING COAL COMBUSTION PRODUCTS

The ever-increasing quantity of by-products generated from burning coal in the production of electricity has brought about the need for new areas of utilization. This study examined the use of FGD gypsum and fluidized bed combustion ash along with Class F fly ash in the production of low-energy, 100% by-product cement blends. The cement blends used the advantageous properties of the by-product materials to create cementing properties rather than energy intensive clinker used in ordinary portland cement. The FGD gypsum was converted to hemihydrate which rapidly hydrated to provide the cement with early strength gains, whilst the fluidized bed combustion ash reacted with the Class F fly ash to form pozzolanic cementitious phases which provided the longer-term compressive strength and possibly resistance to weathering. The rate of compressive strength gains and minimizing detrimental expansion were two properties of particular interest in the study. Chemical admixtures were used to improve the compressive strengths of the cement mortars and decrease their solubility

Nitrite

What is Nitrate? Sodium nitrate is a naturally-occurring substance in vegetables, water, soil, and even the air. Originally discovered as an impurity in salt, small amounts have been used for thousands of years to cure meats

Do Ethicists and Political Philosophers Vote More Often Than Other Professors?

If philosophical moral reflection improves moral behavior, one might expect ethics professors to behave morally better than socially similar non-ethicists. Under the assumption that forms of political engagement such as voting have moral worth, we looked at the rate at which a sample of professional ethicists—and political philosophers as a subgroup of ethicists—voted in eight years’ worth of elections. We compared ethicists’ and political philosophers’ voting rates with the voting rates of three other groups: philosophers not specializing in ethics, political scientists, and a comparison group of professors specializing in neither philosophy nor political science. All groups voted at about the same rate, except for the political scientists, who voted about 10–15% more often. On the face of it, this finding conflicts with the expectation that ethicists will behave more responsibly than non-ethicists