3,075 research outputs found
Soil mechanics on the Moon, Mars, and Mulberry
From a soil mechanics point of view, the Moon is a relatively simple place. Without any water, organics, or clay minerals, the geotechnical properties of the lunar soil are confined to a fairly limited range. Furthermore, the major soil-forming agent is meteorite impact, which breaks the big particles into little particles; and simultaneously, cements the little particles back together again with molten glass. After about a hundred million years of exposure to meteorite impact, the distribution of particle sizes in the soil achieves a sort of steady state. The majority of the returned lunar soil samples have been found to be well-graded silty-sand to sandy-silt (SM in the Unified Soil Classification System). Each of the particle size distributions plots within a relatively narrow band, which appears to be uniform over the entire lunar surface. This further restricts the range of physical properties of the lunar surface. In contrast, Martian soils should exhibit an extremely wide range of properties. We already know that there is a small amount of water in the soil, greater than in the Martian atmosphere. Furthermore, the soil is suspected to be smectitic clay. That makes two out of the three factors that greatly affect the properties of terrestrial soils
Extraction of silymarin compounds from milk thistle (Silybum marianum) seed using hot, liquid water as the solvent
High-value specialty chemicals are usually obtained from natural products by extracting with generally regarded as safe (GRAS) solvents. Because organic solvents are quite often used, high operating and disposal costs occur. When compared to traditional solvents, water is an interesting alternative because of its low operating and disposal costs. Milk thistle contains compounds (taxifolin, silychristin, silydianin, silybinin A, and silybinin B) that display hepatoxic protection properties. This paper examines the batch extraction of silymarin compounds from milk thistle seed meal in 50°C, 70°C, 85°C and 100°C water as a function of time. For taxifolin, silychristin, silybinin A, and silybinin B, extraction with 100°C water resulted in the highest yields. After 210 min of extraction at 100°C, the yield of taxifolin was 1.2 mg/g of seed while the yields of silychristin, silybinin A, and silybinin B were 5.0, 1.8 and 3.3 mg/g of seed, respectively. The ratios of the extracted compounds, and particularly the ratios at long extraction times, showed that the more polar compounds (taxifolin and silychristin) were preferentially extracted at 85°C, while the less polar silybinin was preferentially extracted at 100°C
Alien Registration- Carrier, Arthur D. (Auburn, Androscoggin County)
https://digitalmaine.com/alien_docs/30921/thumbnail.jp
Switchgrass storage effects on the recovery of carbohydrates after liquid hot water pretreatment and enzymatic hydrolysis
Perennial grasses that would be used for bioenergy and bioproducts production will need to be stored for various periods of time to ensure a continual feedstock supply to a bioprocessing facility. The effects of storage practices on grass composition and the response of grasses to subsequent bioprocesses such as pretreatment and enzymatic hydrolysis needs to be understood to develop the most efficient storage protocols. This study examined the effect of outdoor storage of round switchgrass bales on composition before and after liquid hot water pretreatment (LHW) and enzymatic hydrolysis. This study also examined the effect of washing LHW pretreated biomass prior to enzymatic hydrolysis. It was determined that switchgrass composition after baling was stable. As expected, glucan and lignin contents increased after LHW due to decreases in xylan and galactan. Washing biomass prior to enzymatic hydrolysis reduced saccharification, especially in samples from the interior of the bale, by at least 5%
Reformulation of the Stochastic Potential Switching Algorithm and a Generalized Fourtuin-Kasteleyn Representation
A new formulation of the stochastic potential switching algorithm is
presented. This reformulation naturally leads us to a generalized
Fourtuin-Kasteleyn representation of the partition function Z. A formula for
internal energy E and that of heat capacity C are derived from derivatives of
the partition function. We also derive a formula for the exchange probability
in the replica exchange Monte Carlo method. By combining the formulae with the
Stochastic Cutoff method, we can greatly reduce the computational time to
perform internal energy and heat capacity measurements and the replica exchange
Monte Carlo method in long-range interacting systems. Numerical simulations in
three dimensional magnetic dipolar systems show the validity and efficiency of
the method.Comment: 11 pages, 6 figures, to appear in PR
Product Hopping: A New Framework
One of the most misunderstood and anticompetitive business behaviors in today’s economy is “product hopping,” which occurs when a brand-name pharmaceutical company switches from one version of a drug to another. These switches, benign in appearance but not necessarily in effect, can significantly decrease consumer welfare, impairing competition from generic drugs to an extent that greatly exceeds any gains from the “improved” branded product.
The antitrust analysis of product hopping is nuanced. It implicates the intersection of antitrust law, patent law, the Hatch-Waxman Act, and state drug product selection laws. In fact, the behavior is even more complex because it occurs in uniquely complicated markets characterized by doctors who choose the product but don’t pay for it, and consumers who buy the product but don’t choose it. It is thus unsurprising that courts have offered inconsistent approaches to product hopping.
They have paid varying levels of attention to the regulatory structure, offered a simplistic analysis of consumer choice, adopted an underinclusive antitrust standard based on coercion, and focused on whether the brand firm removed the original drug from the market.
Entering this morass, we offer a new framework that courts, government enforcers, plaintiffs, and manufacturers can employ to analyze product hopping. This rigorous and balanced framework is the first to incorporate the economic characteristics of the pharmaceutical industry.
For starters, it defines a “product hop” to include only those instances in which the brand manufacturer (1) reformulates the product in a way that makes the generic non-substitutable and (2) encourages doctors to write prescriptions for the reformulated product rather than the original.
The test also offers two safe harbors, which are more deferential than current caselaw, to ensure that the vast majority of reformulations will not be subject to antitrust scrutiny.
The analysis then examines whether a brand’s product hop passes the “no-economic-sense” test. In other words, would the reformulation make economic sense for the brand if it did not have the effect of impairing generic competition? Merely introducing new products would pass the test. Encouraging doctors to write prescriptions for the reformulated rather than the original product—“cannibalizing” the brand’s own sales—might not. Imposing antitrust liability on behavior that does not make business sense other than through its impairment of generic competition offers a conservative approach and minimizes “false positives” in which courts erroneously find liability. Showing just how far the courts have veered from justified economic analysis, the test would recommend a different analysis than that used in each of the five product-hopping cases that have been litigated to date, and a different outcome in two of them.
By carefully considering the regulatory environment, practicalities of prescription drug markets, manufacturers’ desire for clear-cut rules, and consumers’ needs for a rule that promotes price competition without deterring valued innovations, the framework promises to improve and standardize the antitrust analysis of product hopping
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