143,434 research outputs found
Apparatus for changing the orientation and velocity of a spinning body traversing a path Patent
Development of method and apparatus for spinning satellite about selected axis after reaching predetermined orientatio
Electron temperature in electrically isolated Si double quantum dots
Charge-based quantum computation can be attained through reliable control of
single electrons in lead-less quantum systems. Single-charge transitions in
electrically-isolated double quantum dots (DQD) realised in phosphorus-doped
silicon can be detected via capacitively coupled single-electron tunnelling
devices. By means of time-resolved measurements of the detector's conductance,
we investigate the dots' occupancy statistics in temperature. We observe a
significant reduction of the effective electron temperature in the DQD as
compared to the temperature in the detector's leads. This sets promises to make
isolated DQDs suitable platforms for long-coherence quantum computation.Comment: 4 pages, 3 figure
Multiple structural alignment for distantly related all b structures using TOPS pattern discovery and simulated annealing
Topsalign is a method that will structurally align diverse protein structures, for example, structural alignment of protein superfolds. All proteins within a superfold share the same fold but often have very low sequence identity and different biological and biochemical functions. There is often signiĀ®cant structural diversity around the common scaffold of secondary structure elements of the fold. Topsalign uses topological descriptions of proteins. A pattern discovery algorithm identiĀ®es equivalent secondary structure elements between a set of proteins and these are used to produce an initial multiple structure alignment. Simulated annealing is used to optimize the alignment. The output of Topsalign is a multiple structure-based sequence alignment and a 3D superposition of the structures. This method has been tested on three superfolds: the b jelly roll, TIM (a/b) barrel and the OB fold. Topsalign outperforms established methods on very diverse structures. Despite the pattern discovery working only on b strand secondary structure elements, Topsalign is shown to align TIM (a/b) barrel superfamilies, which contain both a helices and b strands
Terlipressin or norepinephrine in septic shock: do we have the answer?
Comment on
Terlipressin versus norepinephrine as infusion in patients with septic shock: a multicentre, randomised, double-blinded trial. [Intensive Care Med. 2018
Evaluation of the usefulness of a computerābased learning program to support student learning in pharmacology
This study aims to evaluate the effectiveness of a computerābased teaching program in supporting and enhancing traditional teaching methods. The program covers the pharmacology of inflammation and has been evaluated with a group of secondāyear medical students at a UK university. The study assessed subjectāspecific knowledge using a preā and postātest and surveyed, by questionnaire, studentsā perceptions of the usefulness of the program to support learning before and after use. The use of computers for learning amongst this cohort of students was widespread. The results demonstrated an increase in students ā knowledge of the pharmacology of inflammation, coupled with a positive attitude towards the CBL program they had used and the advantages that this mode of study may provide in enabling students to manage their own learning. However, students did not feel that the program could substitute for traditional teaching (lectures)
Hardware configuration for a real-time multiprocessor simulator
The Real-Time Multiprocessor Simulator (RTMPS) is a multiple microcomputer system used to investigate the application of parallel-processing concepts to real-time simulation. This users manual describes the set-up and installation considerations for the RTMPS hardware. Any modifications or further improvements to the RTMPS hardware will be documented in an addendum to this manual
Z' mass limits and the naturalness of supersymmetry
The discovery of a 125 GeV Higgs boson and rising lower bounds on the masses
of superpartners have lead to concerns that supersymmetric models are now fine
tuned. Large stop masses, required for a 125 GeV Higgs, feed into the
electroweak symmetry breaking conditions through renormalisation group
equations forcing one to fine tune these parameters to obtain the correct
electroweak vacuum expectation value. Nonetheless this fine tuning depends
crucially on our assumptions about the supersymmetry breaking scale. At the
same time extensions provide the most compelling solution to the
-problem, which is also a naturalness issue, and allow the tree level
Higgs mass to be raised substantially above . These very well motivated
supersymmetric models predict a new boson which could be discovered at the
LHC and the naturalness of the model requires that the boson mass should
not be too far above the TeV scale. Moreover this fine tuning appears at the
tree level, making it less dependent on assumptions about the supersymmetry
breaking mechanism. Here we study this fine tuning for several
supersymmetric extensions of the Standard Model and compare it to the situation
in the MSSM where the most direct tree level fine tuning can be probed through
chargino mass limits. We show that future LHC searches are extremely
important for challenging the most natural scenarios in these models.Comment: 58 pages, 5 figures; typos corrected, references added; matches
version to be published in Phys. Rev.
Inconsistency in 9 mm bullets : correlation of jacket thickness to post-impact geometry measured with non-destructive X-ray computed tomography
Fundamental to any ballistic armour standard is the reference projectile to be defeated. Typically, for certification purposes, a consistent and symmetrical bullet geometry is assumed, however variations in bullet jacket dimensions can have far reaching consequences. Traditionally, characteristics and internal dimensions have been analysed by physically sectioning bullets ā an approach which is of restricted scope and which precludes subsequent ballistic assessment. The use of a non-destructive X-ray computed tomography (CT) method has been demonstrated and validated Kumar et al., 2011); the authors now apply this technique to correlate bullet impact response with jacket thickness variations. A set of 20 bullets (9 mm DM11) were selected for comparison and an image-based analysis method was employed to map jacket thickness and determine the centre of gravity of each specimen. Both intra- and inter-bullet variations were investigated, with thickness variations of the order of 200 um commonly found along the length of all bullets and angular variations of up to 50 um in some. The bullets were subsequently impacted against a rigid flat plate under controlled conditions (observed on a high-speed video camera) and the resulting deformed projectiles were re-analysed. The results of the experiments demonstrate a marked difference in ballistic performance between bullets from different manufacturers and an asymmetric thinning of the jacket is observed in regions of pre-impact weakness. The conclusions are relevant for future soft armour standards and provide important quantitative data for numerical model correlation and development. The implications of the findings of the work on the reliability and repeatability of the industry standard V50 ballistic test are also discussed
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