1,116 research outputs found
Data on artificial neural network and response surface methodology analysis of biodiesel production
The biodiesel production from waste soybean oil (using NaOH and KOH catalysts independently) was investigated in this study. The use of optimization tools (artificial neural network, ANN, and response surface methodology, RSM) for the modelling of the relationship between biodiesel yield and process parameters was carried out. The variables em- ployed in the experimental design of biodiesel yields were methanol-oil mole ratio (6 â12), catalyst concentration (0.7 â1.7 wt/wt%), reaction temperature (48 â62 °C) and reaction time (50 â90 min). Also, the usefulness of both the RSM and ANN tools in the accurate prediction of the regression mod- els were revealed, with values of R-sq being 0.93 and 0.98 for RSM and ANN respectively
Revisiting Tell Begum. A Prehistoric Site in the Shahizor Valley, Iraqi Kurdistan
Tell Begum was previously explored by Iraqi archaeologists in the 1960s when excavations revealed a multi-period site. Among the key finds were Halaf period remains that are relatively rare in the region of the Shahrizor plain and included polychrome ceramics suggesting a local variation of the Halaf culture. Recent investigations and excavations in 2011 and 2013 revealed a 5 hectare site inhabited during the Halaf, Ubaid, Late Chalcolithic, and medieval periods. The Halaf site may have had an area of about 3 hectares, making it a relatively large settlement for that period, although its full extent is unclear. Offsite work revealed the area to have been well watered in the past, with likely neighbouring regions of woodland and abundant shrubs. The heavy sedimentation in the region has partially obscured archaeological remains, including possibly Tell Begum's lower mound. The site, nevertheless, shows continuity of settlement, indicating relative stability in settlement over long timespans
Non-asymptotically flat, non-AdS dilaton black holes
We show that previously known non-asymptotically flat static black hole
solutions of Einstein-Maxwell-dilaton theory may be obtained as near-horizon
limits of asymptotically flat black holes. Specializing to the case of the
dilaton coupling constant , we generate from the
non-asymptotically flat magnetostatic or electrostatic black holes two classes
of rotating dyonic black hole solutions. The rotating dyonic black holes of the
``magnetic'' class are dimensional reductions of the five-dimensional
Myers-Perry black holes relative to one of the azimuthal angles, while those of
the ``electric'' class are twisted dimensional reductions of rotating dyonic
Rasheed black strings. We compute the quasi-local mass and angular momentum of
our rotating dyonic black holes, and show that they satisfy the first law of
black hole thermodynamics, as well as a generalized Smarr formula. We also
discuss the construction of non-asymptotically flat multi-extreme black hole
configurations.Comment: Minor corrections. 2 references added. To appear in Physical Review
Choroidal vascularity map in unilateral central serous chorioretinopathy: A comparison with fellow and healthy eyes
Background: To map the choroidal vascularity index and compare two eyes in patients with unilateral central serous chorioretinopathy (CSCR). Methods: This was a retrospective, observa-tional study performed in patients with unilateral CSCR. Choroidal thickness (CT) and Choroidal vascularity index (CVI) were measured and mapped in various zones according to the early treatment diabetic retinopathy (ETDRS) grid. Results: A total of 20 CSCR patients (20 study and 20 fellow eyes) were included in the study. Outer nasal region CT was seen to be significantly lower than central CT (p = 0.042) and inner nasal CT (p = 0.007); outer ring CT was significantly less than central (p = 0.04) and inner ring (p = 0.01) CT in CSCR eyes. On potting all the CVI values against the corresponding CT values, a positive correlation was seen in CSCR eyes (r = 0.54, p < 0.01), which was slightly weaker in fellow eyes (r = 0.3, p < 0.01) and a negative correlation was seen in healthy eyes (r = â0.262, p < 0.01). Conclusions: Correlation between CVI and CT was altered in CSCR eyes as compared to fellow and normal eyes with increasing CVI towards the center of the macula and superiorly in CSCR eyes
Modelling of content-aware indicators for effective determination of shot boundaries in compressed MPEG videos
In this paper, a content-aware approach is proposed to design multiple test conditions for shot cut detection, which are organized into a multiple phase decision tree for abrupt cut detection and a finite state machine for dissolve detection. In comparison with existing approaches, our algorithm is characterized with two categories of content difference indicators and testing. While the first category indicates the content changes that are directly used for shot cut detection, the second category indicates the contexts under which the content change occurs. As a result, indications of frame differences are tested with context awareness to make the detection of shot cuts adaptive to both content and context changes. Evaluations announced by TRECVID 2007 indicate that our proposed algorithm achieved comparable performance to those using machine learning approaches, yet using a simpler feature set and straightforward design strategies. This has validated the effectiveness of modelling of content-aware indicators for decision making, which also provides a good alternative to conventional approaches in this topic
Bertotti-Robinson type solutions to Dilaton-Axion Gravity
We present a new solution to dilaton-axion gravity which looks like a
rotating Bertotti-Robinson (BR) Universe. It is supported by an homogeneous
Maxwell field and a linear axion and can be obtained as a near-horizon limit of
extremal rotating dilaton-axion black holes. It has the isometry where U(1) is the remnant of the SO(3) symmetry of BR broken by rotation,
while corresponds to the sector which no longer factors out
of the full spacetime. Alternatively our solution can be obtained from the D=5
vacuum counterpart to the dyonic BR with equal electric and magnetic field
strengths. The derivation amounts to smearing it in D=6 and then reducing to
D=4 with dualization of one Kaluza-Klein two-form in D=5 to produce an axion.
Using a similar dualization procedure, the rotating BR solution is uplifted to
D=11 supergravity. We show that it breaks all supersymmetries of N=4
supergravity in D=4, and that its higher dimensional embeddings are not
supersymmetric either. But, hopefully it may provide a new arena for corformal
mechanics and holography. Applying a complex coordinate transformation we also
derive a BR solution endowed with a NUT parameter.Comment: 21 page
Supergravity Solutions from Floating Branes
We solve the equations of motion of five-dimensional ungauged supergravity
coupled to three U(1) gauge fields using a floating-brane Ansatz in which the
electric potentials are directly related to the gravitational warp factors. We
find a new class of non-BPS solutions, that can be obtained linearly starting
from an Euclidean four-dimensional Einstein-Maxwell base. This class - the
largest known so far - reduces to the BPS and almost-BPS solutions in certain
limits. We solve the equations explicitly when the base space is given by the
Israel-Wilson metric, and obtain solutions describing non-BPS D6 and anti-D6
branes kept in equilibrium by flux. We also examine the action of spectral flow
on solutions with an Israel-Wilson base and show that it relates these
solutions to almost-BPS solutions with a Gibbons-Hawking base.Comment: 24 pages, 1 figur
Design of Lightweight Structural Components for Direct Digital Manufacturing
The rapid growth in direct digital manufacturing technologies has opened the challenge of designing optimal micro-structures for high-performance components. Current topology optimization techniques do not work well for this type of problems and hence in this paper we propose a technique based on an implicit representation of the structural topology. The detailed microstructure is defined by a continuous variable, the size distribution field, defined over the design domain by chosen shape functions. We can optimize the structural topology by optimizing only the weights of the size distribution field and, for any given size distribution, we use standard meshing software to determine the actual detailed micro-structure. We have implemented the optimization loop using commercial CAD and FEA software, running under a genetic algorithm in MATLAB. Application this novel technique to the design of a sandwich beam has produced designs that are superior to any standard solid beam or even optimized truss structure
Managing toxicities associated with immune checkpoint inhibitors: consensus recommendations from the Society for Immunotherapy of Cancer (SITC) Toxicity Management Working Group.
Cancer immunotherapy has transformed the treatment of cancer. However, increasing use of immune-based therapies, including the widely used class of agents known as immune checkpoint inhibitors, has exposed a discrete group of immune-related adverse events (irAEs). Many of these are driven by the same immunologic mechanisms responsible for the drugs\u27 therapeutic effects, namely blockade of inhibitory mechanisms that suppress the immune system and protect body tissues from an unconstrained acute or chronic immune response. Skin, gut, endocrine, lung and musculoskeletal irAEs are relatively common, whereas cardiovascular, hematologic, renal, neurologic and ophthalmologic irAEs occur much less frequently. The majority of irAEs are mild to moderate in severity; however, serious and occasionally life-threatening irAEs are reported in the literature, and treatment-related deaths occur in up to 2% of patients, varying by ICI. Immunotherapy-related irAEs typically have a delayed onset and prolonged duration compared to adverse events from chemotherapy, and effective management depends on early recognition and prompt intervention with immune suppression and/or immunomodulatory strategies. There is an urgent need for multidisciplinary guidance reflecting broad-based perspectives on how to recognize, report and manage organ-specific toxicities until evidence-based data are available to inform clinical decision-making. The Society for Immunotherapy of Cancer (SITC) established a multidisciplinary Toxicity Management Working Group, which met for a full-day workshop to develop recommendations to standardize management of irAEs. Here we present their consensus recommendations on managing toxicities associated with immune checkpoint inhibitor therapy
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