This animal is the main source of naphtochinone-based substances. These compounds have recently drawn medical attention for their use as cardiological and ophthalmological drugs. Unfortunately, after extraction of the naphtochinones, the residual skeletons and spines of the sand dollars were usually discarded.
Here, we report the first method for the preparation of nanostructurally organized spines of S. Application of this method opens the way for development of non-wasteful environmentally clean technology of sand dollars as well-known industrial marine invertebrates. Understanding forgetting from working memory, the memory used in ongoing cognitive processing, is critical to understanding human cognition.
In the last decade a number of conflicting findings have been reported regarding the role of time in forgetting from working memory. This has led to a debate concerning whether longer retention intervals necessarily result in more forgetting. An obstacle to directly comparing conflicting reports is a divergence in methodology across studies. Studies which find no forgetting as a function of retention-interval duration tend to use sequential presentation of memory items, while studies which find forgetting as a function of retention-interval duration tend to use simultaneous presentation of memory items.
Here, we manipulate the duration of retention and the presentation method of memory items, presenting items either sequentially or simultaneously. We find that these differing presentation methods can lead to different rates of forgetting because they tend to differ in the time available for consolidation into working memory.
The experiments detailed here show that equating the time available for working memory consolidation equates the rates of forgetting across presentation methods.
Consolidation of DOC and DPF Functions into a Single Component
We discuss the meaning of this finding in the interpretation of previous forgetting studies and in the construction of working memory models. Evaluation of methods to sample fecal indicator bacteria in foreshore sand and pore water at freshwater beaches. Fecal indicator bacteria FIB are known to accumulate in foreshore beach sand and pore water referred to as foreshore reservoir where they act as a non-point source for contaminating adjacent surface waters.
The effect of different sampling strategies in quantifying the abundance of FIB in the foreshore reservoir is unclear. Sampling was conducted at six freshwater beaches with different sand types to evaluate sampling methods for characterizing the abundance of E. Ankle-depth surface water samples were also collected for comparison. Pore water sampled with a shovel resulted in the highest observed E. There were no statistical differences in E.
Overall, the unsaturated sand had the highest amount of E. The findings presented will help determine the appropriate sampling strategy for characterizing FIB abundance in the foreshore reservoir as a means of predicting its potential impact on nearshore surface water quality and public health risk. All rights.
Parts & Components
To explore the germination conditions of Lonicera hypoglauca sand culture seeds and the effects of sand culture seedlings sterilization. Different sterilization treatments and different hardening-seedling days were used to test the sterilization effect of sand culture seedlings. The treatment of detergent liquor scrub-tap water wash on the part above the hypocotyl, which was sand cultured under the opening condition and had no root, showed the best sterilization effect, with the average pollution rate was zero, and the average survival rate peaked at The sterilization effect of sand culture seedlings, which was disinfected after cleaning by detergent liquor scrub-tap water wash after hardening-seeding for 30 days, was the best, with the average pollution rate of The treatment of detergent liquor scrub-tap water wash treatment on the part above the hypocotyl,which is sand cultured under the opening condition and had no root, shows the best sterilization effect.
For the sand culture seedlings, before inoculated in subculture medium, should be hardening-seedling for some days and sterilized after detergent liquor scrub-tap water wash. In situ consolidation of offshore petroleum well structural casings by electrokinetic methods.
Offshore drilling operations encounter cement wash-out problems while setting the initial structural casing ft depth due to the soft, unconsolidated nature of the sea-bed. This dissertation presents a method of increasing the bearing capacity of a jet-drilled or slick-drilled casing in-situ by applying a potential difference such that the casing is anodic compared to a remote cathode. It has been shown experimentally that clayey formations will swell and stick to a simulated anodic casing by the combined electrokinetic processes of electroosmosis and electrophoresis.
The Influences of Emotion on Learning and Memory
Any cavities around the "casing" are eliminated and the formation is flush against the metal surface, increasing bearing capacity. The formation around the "casing" dries out due to electroosmotic migration of water away from the anode, increasing the shear strength of the surrounding soil. Corrosion products at the anode can further increase the soil shear strength by a process known as electrochemical hardening.
The existence of an optimal level of electrokinetic consolidation , beyond which the soil shear strength begins to degrade, has been demonstrated. The difficulties of applying electrokinetic methods to saline soil environments have been addressed and the process has been shown to be successful, as long as the requisite electric field strength is maintained.
The efficiency of the electrokinetic consolidation technique has been shown to be affected by the soil water content, soil mineralogy, power supplied, time of treatment and the choice of anode material. Comparison of methods for determination of total oil sands -derived naphthenic acids in water samples. There are several established methods for the determination of naphthenic acids NAs in waters associated with oil sands mining operations.
Due to their highly complex nature, measured concentration and composition of NAs vary depending on the method used. This study compared different common sample preparation techniques, analytical instrument methods , and analytical standards to measure NAs in groundwater and process water samples collected from an active oil sands operation. The gas chromatography mass spectrometry GC-MS methods consistently had the highest NA concentrations and greatest standard error. Total NAs concentration was not statistically different between sample preparation of solid phase extraction and liquid-liquid extraction.
Calibration standards influenced quantitation results. This work provided a comprehensive understanding of the inherent differences in the various techniques available to measure NAs and hence the potential differences in measured amounts of NAs in samples.
Results from this study will contribute to the analytical method standardization for NA analysis in oil sands related water samples. All rights reserved. Solution of the one-dimensional consolidation theory equation with a pseudospectral method. The one-dimensional consolidation theory equation is solved for an aquifer system using a pseudospectral method.
The spatial derivatives are computed using Fast Fourier Transforms and the time derivative is solved using a fourth-order Runge-Kutta scheme. The computer model calculates compaction based on the void ratio changes accumulated during the simulated periods of time. Compactions and expansions resulting from groundwater withdrawals and recharges are simulated for two observation wells in Santa Clara Valley and two in San Joaquin Valley, California.
Field data previously published are used to obtain mean values for the soil grain density and the compression index and to generate depth-dependent profiles for hydraulic conductivity and initial void ratio. The water-level plots for the wells studied were digitized and used to obtain the time dependent profiles of effective stress. Pressurized Anneal of Consolidated Powders. Systems and methods for producing a dense, well bonded solid material from a powder may include consolidating the powder utilizing any suitable consolidation method , such as explosive shockwave consolidation.
The systems and methods may also include a post-processing thermal treatment that exploits a mismatch between the coefficients of thermal expansion between the consolidated material and the container. Due to the mismatch in the coefficients, internal pressure on the consolidated material during the heat treatment may be increased.
Method of producing drive fluid in situ in tar sands formations. Methods of treating a tar sands formation are described herein. Methods for treating a tar sands may include providing heat to at least part of a hydrocarbon layer in the formation from one or more heaters located in the formation. The heat may be allowed to transfer from the heaters to at least a portion of the formation such that a drive fluid is produced in situ in the formation.
Alternative theoretical method for motion of a sand -filled funnel experiment. They wrote for noncalculus-based physics classes, but we solve the same problem using the methods of calculus. This can help introductory physics students understand a broader definition of Newton's second law and enhance their calculus skills. It also teaches students how to solve a variable-mass problem.
There were two purposes for this mixed methods study: to investigate a the realistic meaning of awareness and understanding as the underlying constructs of general knowledge of the learning process and b a procedure for data consolidation. The participants were 11th-grade high school and first-year university students. Integrated data…. Method of tagging sand with ruthenium and the resultant product.
A procedure for tagging sand with a radioisotope for use in the study of sediment transport involves the precipitation of a metal radioisotope in the form of an iodide directly on the sand , followed by heating the sand to a temperature sufficient to effect a phase transformation of the sand and a decomposition of the metal iodide, leaving the metal firmly attached to the sand.