The Toxicity of Acetaminophen, Caffeine and Carbendazim in Earthworms (Eisenia fetida)

There has been a need for the assessment of ground water contamination risk on terrestrial organisms. One terrestrial organism, Eisenia fetida, was chosen as a test species and exposed to three common pharmaceutical and/or pesticide related contaminants: acetaminophen (CAS#103-90-2), caffeine (CAS#58-08-2) and carbendazim (CAS#10605-21-7), respectively. Levels of contamination varied from grams per liter to micrograms per liter (ppb) using distilled water as the solvent. Eisenia fetida was examined through a 28 day range/index toxicity test. A Benchmark Dose (BMD) dichotomous probit analysis, using a 95% confidence interval, was calculated for all three contaminants. All three contaminants were found to have Benchmark Dose Lower 95 % Confidence Intervals (BMDL\u27s) well below levels of full saturation (BMD/BMDL of Acetaminophen: 160ppm/100pm; Caffeine: 120ppm/50ppm; Carbendazim: 71ppb/41ppb), with hazard quotients of 3.8 x 10-e, 2.6 x 10-5 and 2.9 x 10-3, respectively. These three contaminants showed that despite low levels of ground water contamination found currently in the United States several terrestrial organisms and ecosystems could be severely impacted

The Toxicity of Acetaminophen, Caffeine and Carbendazim in Earthworms (Eisenia fetida)

There has been a need for the assessment of ground water contamination risk on terrestrial organisms. One terrestrial organism, Eisenia fetida, was chosen as a test species and exposed to three common pharmaceutical and/or pesticide related contaminants: acetaminophen (CAS#103-90-2), caffeine (CAS#58-08-2) and carbendazim (CAS#10605-21-7), respectively. Levels of contamination varied from grams per liter to micrograms per liter (ppb) using distilled water as the solvent. Eisenia fetida was examined through a 28 day range/index toxicity test. A Benchmark Dose (BMD) dichotomous probit analysis, using a 95% confidence interval, was calculated for all three contaminants. All three contaminants were found to have Benchmark Dose Lower 95 % Confidence Intervals (BMDL\u27s) well below levels of full saturation (BMD/BMDL of Acetaminophen: 160ppm/100pm; Caffeine: 120ppm/50ppm; Carbendazim: 71ppb/41ppb), with hazard quotients of 3.8 x 10-e, 2.6 x 10-5 and 2.9 x 10-3, respectively. These three contaminants showed that despite low levels of ground water contamination found currently in the United States several terrestrial organisms and ecosystems could be severely impacted

Strutjet Matures to Support Propulsion Needs in the 2000+ World

The Strutjet, Aerojet's Rocket Based Combined Cycle (RBCC) concept, was discussed in a previous ISABE paper as an enabling propulsion concept for single stage to orbit applications. This paper describes the technical progress of the Strutjet since 1996 together with a rationale why RBCC engines in general and the Strutjet in particular, lend themselves uniquely to systems having the ability to expand current space and also open new global "rapid delivery" markets. In particular, the paper substantiates the claims why for certain missions RBCC powered vehicles can be operated at higher margins than all rocket systems, and why within the family of conceivable RBCC systems the Strutjet excels due to its unique architecture and design features. A special emphasis is given to the selection of the engine's ram/scram mode design point because only that mode can add significantly to the mission effective Isp. The thrust produced by an airbreathing engine is directly related to the mass of air processed. This air is captured by the inlet and compressed to raise the pressure for combustion and subsequent expansion. The net accelerating force is the difference between the gross thrust and total vehicle drag (including the spill drag). This total drag is highest at low speeds when the gross thrust is lowest. When the net accelerating force is low, most of the fuel burned is wasted overcoming the vehicle drag. Higher thrust is necessary to perform the mission. One method is to leave the rockets on longer but this results in much higher propellant consumption

How to achieve resilience as an older widower: turning points or gradual change?

ABSTRACT The paper draws together two conceptualisations of resilience in bereavement and widowhood that were developed b

Kinetic Resolution in Asymmetric Epoxidation using Iminium Salt Catalysis

The first reported examples of kinetic resolution in epoxidation reactions using iminium salt catalysis are described, providing up to 99% ee in the epoxidation of racemic cis-chromenes

New biphenyl iminium salt catalysts for highly enantioselective asymmetric epoxidation: role of additional substitution and dihedral angle

New biaryl iminium salt catalysts for enantioselective alkene epoxidation containing additional substitution in the heterocyclic ring are reported. The effects upon conformation and enantioselectivity of this additional substitution, and the influence of dihedral angle in these systems, has been investigated using a synthetic approach supported by density functional theory. Enantioselectivities of up to 97% ee were observed

On covers of cyclic acts over monoids

In (Bull. Lond. Math. Soc. 33:385–390, 2001) Bican, Bashir and Enochs finally solved a long standing conjecture in module theory that all modules over a unitary ring have a flat cover. The only substantial work on covers of acts over monoids seems to be that of Isbell (Semigroup Forum 2:95–118, 1971), Fountain (Proc. Edinb. Math. Soc. (2) 20:87–93, 1976) and Kilp (Semigroup Forum 53:225–229, 1996) who only consider projective covers. To our knowledge the situation for flat covers of acts has not been addressed and this paper is an attempt to initiate such a study. We consider almost exclusively covers of cyclic acts and restrict our attention to strongly flat and condition (P) covers. We give a necessary and sufficient condition for the existence of such covers and for a monoid to have the property that all its cyclic right acts have a strongly flat cover (resp. (P)-cover). We give numerous classes of monoids that satisfy these conditions and we also show that there are monoids that do not satisfy this condition in the strongly flat case. We give a new necessary and sufficient condition for a cyclic act to have a projective cover and provide a new proof of one of Isbell’s classic results concerning projective covers. We show also that condition (P) covers are not unique, unlike the situation for projective covers

The Strutjet Rocket Based Combined Cycle Engine

The multi stage chemical rocket has been established over many years as the propulsion System for space transportation vehicles, while, at the same time, there is increasing concern about its continued affordability and rather involved reusability. Two broad approaches to addressing this overall launch cost problem consist in one, the further development of the rocket motor, and two, the use of airbreathing propulsion to the maximum extent possible as a complement to the limited use of a conventional rocket. In both cases, a single-stage-to-orbit (SSTO) vehicle is considered a desirable goal. However, neither the "all-rocket" nor the "all-airbreathing" approach seems realizable and workable in practice without appreciable advances in materials and manufacturing. An affordable system must be reusable with minimal refurbishing on-ground, and large mean time between overhauls, and thus with high margins in design. It has been suggested that one may use different engine cycles, some rocket and others airbreathing, in a combination over a flight trajectory, but this approach does not lead to a converged solution with thrust-to-mass, specific impulse, and other performance and operational characteristics that can be obtained in the different engines. The reason is this type of engine is simply a combination of different engines with no commonality of gas flowpath or components, and therefore tends to have the deficiencies of each of the combined engines. A further development in this approach is a truly combined cycle that incorporates a series of cycles for different modes of propulsion along a flight path with multiple use of a set of components and an essentially single gas flowpath through the engine. This integrated approach is based on realizing the benefits of both a rocket engine and airbreathing engine in various combinations by a systematic functional integration of components in an engine class usually referred to as a rocket-based combined cycle (RBCC) engine. RBCC engines exhibit a high potential for lowering the operating cost of launching payloads into orbit. Two sources of cost reductions can be identified. First, RBCC powered vehicles require only 20% takeoff thrust compared to conventional rockets, thereby lowering the thrust requirements and the replacement cost of the engines. Second, due to the higher structural and thermal margins achievable with RBCC engines coupled with a higher degree of subsystem redundance lower maintenance and operating cost are obtainable