252 research outputs found
Analysis of the light dependent resistor configuration for line tracking robot application
Modern days, a robot can be designed based on human needs. In particular, the line tracking robot is a classic introductory robot design and needs minimal amount of material and cost. The aim of this project is to construct a robot that has capability to follow the white line placed on a horizontal smooth surface lighted by LED and the low cost light dependant resistor as the sensor. Rigorous analysis has been applied to determine the optimal configuration for the sensor on the mobile robot. Our findings show that angle of LDR of 30°, the distance between LDR and LED of 2.5cm and height of 2cm is the best configuration. The line tracking robot will detect the light intensity that is rebounded from the white color path
Design and analysis of DLS steel/composite thick-adhernd adhesive joints
The paper describes experimental and numerical techniques to study the structural design and behaviourof thick-adherend DLS joints that are based on steel /steel and steel/composites and epoxy adhesives, withfocus on long overlap joints. A standard fabrication method was followed to produce 60 specimens of
various dimensions and materials
Non-linear microwave impedance of short and long Josephson Junctions
The non-linear dependence on applied field () or current () of the microwave (ac) impedance of both
short and long Josephson junctions is calculated under a variety of excitation
conditions. The dependence on the junction width is studied, for both field
symmetric (current anti-symmetric) and field anti-symmetric (current symmetric)
excitation configurations.The resistance shows step-like features every time a
fluxon (soliton) enters the junction, with a corresponding phase slip seen in
the reactance. For finite widths the interference of fluxons leads to some
interesting effects which are described. Many of these calculated results are
observed in microwave impedance measurements on intrinsic and fabricated
Josephson junctions in the high temperature superconductors, and new effects
are suggested. When a field () or current () is applied,
interesting phase locking effects are observed in the ac impedance
. In particular an almost periodic dependence on the dc bias is
seen similar to that observed in microwave experiments at very low dc field
bias. These results are generic to all systems with a potential
in the overdamped limit and subjected to an ac drive.Comment: 7 pages, 11 figure
Inter-laboratory assessment by trained panelists from France and the United Kingdom of beef cooked at two different end-point temperatures
Extracting cosmological signals from foregrounds in deep mm maps of the sky
The high Galactic latitude sky at millimeter and submm wavelengths contains
significant cosmological information about the early Universe (in terms of the
cosmic microwave background) but also the process of structure formation in the
Universe from the far infrared background produced by early galaxies and the
Sunyaev-Zeldovich effect in clusters of galaxies. As the Planck mission will
produce full sky maps in this frequency range, deeper maps of selected
low-foregrounds patches of the sky can produce complementary and important
information. Here we analyze the performance of a balloon-borne survey covering
a 10^\circ x 10^\circ patch of the sky with a few arcminute resolution and very
high pixel sensitivity. We simulate the different components of the mm/submm
sky (i.e., CMB anisotropies, SZ effect, radio and infrared sources, far
infrared background, and interstellar dust) using current knowledge about each
of them. We then combine them, adding detector noise, to produce detailed
simulated observations in four observational bands ranging from 130 to 500 GHz.
Finally, we analyze the simulated maps and estimate the performance of the
instrument in extracting the relevant information about each of the components.
We find that the CMB angular power spectrum is accurately recovered up to l ~
3000. Using the Sunyaev-Zel'dovich effect, most of the galaxy clusters present
in our input map are detected (60% efficiency overall). Our results also show
that much stronger constrains can be placed on far infrared background models.Comment: 10 pages, 8 figures, accepted for publication in A&
Using field-based entomological research to promote awareness about forest ecosystem conservation
Interactions between plants, insect herbivores and associated predators represent the majority of terrestrial biodiversity. Insects are vital food sources for many other organisms and provide important ecosystem functions and services including pollination, waste removal and biological control. We propose a complete and reproducible education programme to guide students to understand the importance of managing and conserving forest ecosystems in their region through the study of insect ecology and natural history. Our programme involved lectures, workshops and field surveys of insects with a group of 60 high school students in Eastern Africa (Ethiopia). It addresses the key stages of an entomological research project including: 1) general entomological knowledge and understanding the role of insects in terrestrial diversity and in ecosystem functioning and services; (2) the proposal of simple research questions including hypothesis development and evaluation using scientific literature, 3) fieldwork using different types of light traps; 4) sorting and identification of the insect orders using simple diagnostic keys and illustrated plates; 5) analysing and interpreting the results and 6) demonstrating findings to peers and a public audience. Identifying insects, exploring their natural history and understanding their functions in the field bring the students towards a better understanding and awareness of the importance of forest ecosystem conservation
On the ability of spectroscopic SZ effect measurements to determine the temperature structure of galaxy clusters
(abridged) We explore in this paper the ability of spatially resolved
spectroscopic measurements of the SZ effect (SZE) to determine the temperature
profile of galaxy clusters. We derive a general formalism for the thermal SZE
in galaxy clusters with a non-uniform temperature profile that can be applied
to both cool-core clusters and non-cool core cluster with an isothermal or
non-isothermal temperature structure. We derive an inversion technique through
which the electron distribution function can be extracted from spectroscopic
SZE observations over a wide frequency range. We study the fitting procedure to
extract the cluster temperature from a set of simulated spatially resolved
spectroscopic SZE observations in different bands of the spectrum, from 100 to
450 GHz. The results of our analysis for three different cluster prototypes
(A2199 with a low-temperature cool core, Perseus with a relatively
high-temperature cool core, Ophiuchus with an isothermal temperature
distribution) provide both the required precision of the SZE observations and
the optimal frequency bands for a determination of the cluster temperature
similar or better than that obtainable from X-ray observations. The precision
of SZE-derived temperature is also discussed for the outer regions of clusters.
We also study the possibility to extract, from our method, the parameters
characterizing the non-thermal SZE spectrum of the relativistic plasma
contained in the lobes of radio galaxies as well as the spectrum of
relativistic electrons co-spatially distributed with the thermal plasma in
clusters with non-thermal phenomena. We find that the next generation SZE
experiments with spectroscopic capabilities can provide precise temperature
distribution measurements (...)Comment: Submitted to Astronomy & Astrophysic
pRb/E2F-1-mediated caspase-dependent induction of Noxa amplifies the apoptotic effects of the Bcl-2/Bcl-xL inhibitor ABT-737
Although Bcl-2 family members control caspase activity by regulating mitochondrial permeability, caspases can, in turn, amplify the apoptotic process upstream of mitochondria by ill-characterized mechanisms. We herein show that treatment with a potent inhibitor of Bcl-2 and Bcl-xL, ABT-737, triggers caspase-dependent induction of the BH3-only protein, Mcl-1 inhibitor, Noxa. RNA interference experiments reveal that induction of Noxa, and subsequent cell death, rely not only on the transcription factor E2F-1 but also on its regulator pRb. In response to ABT-737, pRb is cleaved by caspases into a p68Rb form that still interacts with E2F-1. Moreover, pRb occupies the noxa promoter together with E2F-1, in a caspase-dependent manner upon ABT-737 treatment. Thus, caspases contribute to trigger the mitochondrial apoptotic pathway by coupling Bcl-2/Bcl-xL inhibition to that of Mcl-1, via the pRb/E2F-1-dependent induction of Noxa
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