Mechanical Properties of Sandstone using non-Destructive Method

The understanding of physical and mechanical properties of rock is considered as critical in drilling, geo-engineering, and construction applications. As an example, the awareness of these rock parameters contributes to avoid or minimizing instability around the wellbore while drilling. The laboratory experiment of understanding of these parameters can be done in two-different ways: static, where the sample subjects to destruction after the test and dynamic, known as non-destruction method. The non-destructive method using ultrasonic waves under a series of different stress conditions, starting from 7 to 56 MPa with incrementation of 7MPa, has been used in this paper in order to characterize the mechanical properties of dry Zbylutów sandstone at 20 and 80°C. The velocity of primary (P) and secondary (S) waves within these ranges has been recorded in order to understand the behavior of the mechanical properties. The results showed that the Young’s modulus, bulk modulus, shear modulus, and Lame’s constant of Zbylutów sandstone have a positive correlation with good coefficient correlation with the increased stress, while the Poisson’s ratio showed a negative correlation. Besides, the effect of temperature on the rock parameters is approved by the decrease of primary wave velocity in this two-different temperature range. Such results are necessary when preparing the appropriate mud weight for drilling process, which is related to wellbore instability

An analysis of a temperature change in a cross‑section of borehole heat exchanger

Underground heat exchangers (BHE) are used witch elements to transport energy between the ground and other objects on the surface of the land. For simplification described in mathematical apparatus, they works are explain how linear heat source. The temperature is the same in all bodies of this model. This reduction to let easy describe theoretical changes temperature in BHE through transporting energy to / from rock in analytic mathematic method. The bad effect of this method is present by the same value of temperature in horizontal cross‑section and along BHE. The analysis of change of temperature field in the sealing cement BHE is a possibility for numerical simulation or laboratory model. Computer simulation needed according energy transport law. It to say about quantity of energy conducting between horizontal cross‑section of BHE cells, on which is divided. The second method obtains value of temperature points of the sealing cement. This is to be realized by sensors set up in to the horizontal cross‑section of BHE of laboratory model. This is possible thanks constructed the model of cross‑section of BHE

Macrophilones from the Marine Hydroid <i>Macrorhynchia philippina</i> Can Inhibit ERK Cascade Signaling

Six new macrophilone-type pyrroloiminoquines were isolated and identified from an extract of the marine hydroid <i>Macrorhynchia philippina</i>. The proton-deficient and heteroatom-rich structures of macrophilones B–G (<b>2</b>–<b>7</b>) were elucidated by spectroscopic analysis and comparison of their data with those of the previously reported metabolite macrophilone A (<b>1</b>). Compounds <b>1</b>–<b>7</b> are the first pyrroloiminoquines to be reported from a hydroid. The macrophilones were shown to inhibit the enzymatic conjugation of SUMO to peptide substrates, and macrophilones A (<b>1</b>) and C (<b>3</b>) exhibit potent and selective cytotoxic properties in the NCI-60 anticancer screen. Bioinformatic analysis revealed a close association of the cytotoxicity profiles of <b>1</b> and <b>3</b> with two known B-Raf kinase inhibitory drugs. While compounds <b>1</b> and <b>3</b> showed no kinase inhibitory activity, they resulted in a dramatic decrease in cellular protein levels of selected components of the ERK signal cascade. As such, the chemical scaffold of the macrophilones could provide small-molecule therapeutic leads that target the ERK signal transduction pathway

Research-led placements in politics : a new approach?

The 'scholarship of engagement', derived from work undertaken by the Boyer Commission in the US, emphasises the possibilities of enhanced undergraduate learning through research, yet in the UK this idea is less developed. Moreover, although the study of politics and international relations lends itself well to the use of placements to develop this model of learning, there are few examples of this in the UK. This article presents findings from a major research project, the Scholarship of Engagement for Politics, examining the ways in which placement learning can affect the student experience