scholarly journals Thermal Fringe Formation During a Hologram Recording Using a Dry Photopolymer

Photonics ◽  
2021 ◽  
Vol 8 (12) ◽  
pp. 589
Author(s):  
Friedrich-Karl Bruder ◽  
Thomas Fäcke ◽  
Thomas Rölle
Keyword(s):  
Coefficient Of Thermal Expansion ◽  
Hologram Recording ◽  
Optical Elements ◽  
Linear Coefficient ◽  
Large Size ◽  
Exposure Interval ◽  
Different Types ◽  
Recording Conditions ◽  
The One ◽  
Size Display

In this study we investigated the undesired but possible fringe formation during the recording of large size holographic optical elements (HOE) using a dry photopolymer. We identified the deformation of the recording element during hologram exposure as the main source for this fringe formation. This deformation is caused mainly by the one-sided heating of the recording element, namely, the dry photopolymer–recording plate stack. It turned out that the main source for this heating was the heat of polymerization in the dry photopolymer released during the exposure interval. These insights were translated into a physical model with which quantitative predictions about thermal fringe formation can be made depending on the actual HOE recording geometry, recording conditions and characteristics of the dry photopolymer. Using this model, different types of large size HOEs, used as components to generate a steerable confined view box for a 23” diagonal size display demonstrator, could be recorded successfully without thermal fringe formation. Key strategies to avoid thermal fringe formation deduced from this model include balancing the ratio of lateral recording plate dimension R to its thickness h, recording the power density P or equivalently the exposure time texp at a fixed recording dosage E, and most importantly recording the the linear coefficient of thermal expansion (CTE) of the recording plate material. Suitable glass plates with extremely low CTE were identified and used for recording of the above-mentioned HOEs.

scholarly journals A Bird’s-Eye View of Cell Sources for Cell-Based Therapies in Blood Cancers

Cancers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1333
Author(s):  
Benjamin Motais ◽  
Sandra Charvátová ◽  
Matouš Hrdinka ◽  
Michal Šimíček ◽  
Tomáš Jelínek ◽  
...  
Keyword(s):  
Hematological Malignancies ◽  
Antigen Receptors ◽  
Chimeric Antigen Receptors ◽  
Blood Cancer ◽  
Cell Based Therapy ◽  
Cell Source ◽  
Different Types ◽  
Cell Sources ◽  
The One ◽  
Initial Results

Hematological malignancies comprise over a hundred different types of cancers and account for around 6.5% of all cancers. Despite the significant improvements in diagnosis and treatment, many of those cancers remain incurable. In recent years, cancer cell-based therapy has become a promising approach to treat those incurable hematological malignancies with striking results in different clinical trials. The most investigated, and the one that has advanced the most, is the cell-based therapy with T lymphocytes modified with chimeric antigen receptors. Those promising initial results prepared the ground to explore other cell-based therapies to treat patients with blood cancer. In this review, we want to provide an overview of the different types of cell-based therapies in blood cancer, describing them according to the cell source.

scholarly journals Generation of Multiple Vector Optical Bottle Beams

Photonics ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 218
Author(s):  
Svetlana N. Khonina ◽  
Alexey P. Porfirev ◽  
Sergey G. Volotovskiy ◽  
Andrey V. Ustinov ◽  
Sergey A. Fomchenkov ◽  
...  
Keyword(s):  
Intensity Distribution ◽  
Polarization State ◽  
Spatial Dynamics ◽  
Surface Structures ◽  
Optical Traps ◽  
Spatial Transformation ◽  
Optical Elements ◽  
Periodic Surface ◽  
Matter Interaction ◽  
Different Types

We propose binary diffractive optical elements, combining several axicons of different types (axis-symmetrical and spiral), for the generation of a 3D intensity distribution in the form of multiple vector optical ‘bottle’ beams, which can be tailored by a change in the polarization state of the illumination radiation. The spatial dynamics of the obtained intensity distribution with different polarization states (circular and cylindrical of various orders) were investigated in paraxial mode numerically and experimentally. The designed binary axicons were manufactured using the e-beam lithography technique. The proposed combinations of optical elements can be used for the generation of vector optical traps in the field of laser trapping and manipulation, as well as for performing the spatial transformation of the polarization state of laser radiation, which is crucial in the field of laser-matter interaction for the generation of special morphologies of laser-induced periodic surface structures.

Plausibility and Aesthetic Interpretation

1977 ◽  
Vol 7 (2) ◽  
pp. 327-340 ◽  
Author(s):  
Denis Dutton
Keyword(s):  
Scientific Inquiry ◽  
The Other ◽  
Inquiry Science ◽  
Works Of Art ◽  
Different Types ◽  
Logical Structures ◽  
The One

If a catalogue were made of terms commonly used to affirm the adequacy of critical interpretations of works of art, one word certain to be included would be “plausible.” Yet this term is one which has received precious little attention in the literature of aesthetics. This is odd, inasmuch as I find the notion of plausibility central to an understanding of the nature of criticism. “Plausible” is a perplexing term because it can have radically different meanings depending on the circumstances of its employment. ln the following discussion, I will make some observations about the logic of this concept in connection with its uses in two rather different contexts: the context of scientific inquiry on the one hand, and that of aesthetic interpretation on the other. In distinguishing separate senses of “plausible,” I shall provide reason to resist the temptation to imagine that because logical aspects of two different types of inquiry—science and criticism—happen to be designated by the same term, they may to that extent be considered to have similar logical structures.

Fluid turbulence simulations of divertor heat load for ITER hybrid scenario using BOUT++

2021 ◽  
Author(s):  
Xueyun Wang ◽  
Xueqiao Xu ◽  
Philip B Snyder ◽  
Zeyu Li
Keyword(s):  
Heat Flux ◽  
Steady State ◽  
Energy Loss ◽  
Heat Load ◽  
Type I ◽  
Fluid Turbulence ◽  
Drift Model ◽  
Steady State Operation ◽  
Different Types ◽  
The One

Abstract The BOUT++ six-field turbulence code is used to simulate the ITER 11.5MA hybrid scenario and a brief comparison is made among ITER baseline, hybrid and steady-state operation (SSO) scenarios. Peeling-ballooning instabilities with different toroidal mode numbers dominate in different scenarios and consequently yield different types of ELMs. The energy loss fractions (ΔWped/Wped) caused by unmitigated ELMs in the baseline and hybrid scenarios are large (~2%) while the one in the SSO scenario is dramatically smaller (~1%), which are consistent with the features of type-I ELMs and grassy ELMs respectively. The intra ELM divertor heat flux width in the three scenarios given by the simulations is larger than the estimations for inter ELM phase based on Goldston’s heuristic drift model. The toroidal gap edge melting limit of tungsten monoblocks of divertor targets imposes constraints on ELM energy loss, giving that the ELM energy loss fraction should be smaller than 0.4%, 1.0%, and 1.2% for ITER baseline, hybrid and SSO scenarios, correspondingly. The simulation shows that only the SSO scenario with grassy ELMs may satisfy the constraint.

scholarly journals Evaluation of a Handheld Gluten Detection Device

2018 ◽  
Vol 81 (10) ◽  
pp. 1723-1728 ◽  
Author(s):  
STEVE L. TAYLOR ◽  
JULIE A. NORDLEE ◽  
SHYAMALI JAYASENA ◽  
JOSEPH L. BAUMERT
Keyword(s):  
Ice Cream ◽  
Weight Basis ◽  
Processed Foods ◽  
Gluten Free ◽  
Specific Enzyme ◽  
Different Types ◽  
Food Matrices ◽  
The One ◽  
Addition Level ◽  
Positive Results

ABSTRACT A portable, handheld gluten detection device, the Nima sensor, is now available for consumers wishing to determine if gluten is present in food. By U.S. regulation, gluten-free foods should contain <20 ppm of gluten. Thirteen gluten-free foods (muffins, three different types of bread, three different types of pasta, puffed corn snack, ice cream, meatballs, vinegar and oil salad dressing, oatmeal, and dark chocolate) were prepared; each food was spiked on a weight to weight basis with gluten levels of 0, 5, 10, 20, 30, 40, and 100 ppm before processing or preparation. Unprocessed and processed foods were tested with the handheld gluten sensor and by two gluten-specific enzyme-linked immunosorbent assays (ELISAs) on the basis of the R5 and G12 monoclonal antibodies, respectively. The portable gluten detection device detected gluten in all food types at the 30-ppm addition level, failing to detect gluten in only 5 (6.4%) of 78 subsamples. At the 20-ppm addition level, the portable gluten detection device failed to detect gluten in one type of pasta but detected gluten residues in 63 (87.5%) of 72 other subsamples. The device was able to detect gluten at the 10-ppm addition level in 9 of the 13 food matrices (41 of 54 subsamples, 75.9%) but not in the three types of pasta and the puffed corn snack. The gluten-sensing device did not perform reliably at the 5-ppm addition level in 11 of 13 food matrices (exceptions: ice cream and muffins). In contrast, the ELISA methods were highly reliable at gluten addition levels of ≥10 ppm in all food matrices. The portable gluten detection device yielded a low percentage of false-positive results (4 of 111, 3.6%) in these food matrices. Thus, this handheld portable gluten sensor performed reliably in the detection of gluten in foods having ≥20 ppm of added gluten with only 18 (5.9%) of 306 failures, if results of the one type of pasta are excluded. The device worked with greater reliability as the gluten levels in the foods increased.

scholarly journals Influence of misalignments on the performance of externally occulted solar coronagraphs

2018 ◽  
Vol 612 ◽  
pp. A82 ◽  
Author(s):  
S. V. Shestov ◽  
A. N. Zhukov
Keyword(s):  
European Space Agency ◽  
Numerical Approach ◽  
Primary Objective ◽  
Optical Elements ◽  
Trade Off ◽  
Space Agency ◽  
Minimal Height ◽  
Different Types ◽  
Points Of View ◽  
Quantitative Influence

Context. The ASPIICS instrument is a novel externally occulted coronagraph that will be launched on board the PROBA-3 mission of the European Space Agency. The external occulter will be placed on one satellite ~150 m ahead of the second satellite that will carry an optical instrument. During 6 h out of 19.38 h of orbit, the satellites will fly in a precise (accuracy around a few millimeters) formation, constituting a giant externally occulted coronagraph. The large distance between the external occulter and the primary objective will allow observations of the white-light solar corona starting from extremely low heights ~ 1.1R⊙. Aims. We intend to analyze influence of shifts of the satellites and misalignments of optical elements on the ASPIICS performance in terms of diffracted light. Based on the quantitative influence of misalignments on diffracted light, we provide a recipe for choosing the size of the internal occulter (IO) to achieve a trade-off between the minimal height of observations and sustainability to possible misalignments. Methods. We considered different types of misalignments and analyzed their influence from optical and computational points of view. We implemented a numerical model of the diffracted light and its propagation through the optical system and computed intensities of diffracted light throughout the instrument. Our numerical approach is based on a model from the literature that considered the axisymmetrical case. Here we extend the model to include nonsymmetrical cases and possible misalignments. Results. The numerical computations fully confirm the main properties of the diffracted light that we obtained from semi-analytical consideration. We obtain that relative influences of various misalignments are significantly different. We show that the internal occulter with RIO = 1.694 mm = 1.1R⊙ is large enough to compensate possible misalignments expected to occur in PROBA-3/ASPIICS. Besides that we show that apodizing the edge of the internal occulter leads to additional suppression of the diffracted light. Conclusions. We conclude that the most important misalignment is the tilt of the telescope with respect to the line connecting the center of the external occulter and the entrance aperture. Special care should be taken to co-align the external occulter and the coronagraph, which means co-aligning the diffraction fringe from the external occulter and the internal occulter. We suggest that the best orientation strategy is to point the coronagraph to the center of the external occulter.

scholarly journals Fracture of Be and Its Alloys - Webb Space Telescope Revisited

2021 ◽  
Author(s):  
Muhammad Musaddique Ali Rafique
Keyword(s):  
Near Infrared ◽  
Joint Venture ◽  
Coefficient Of Thermal Expansion ◽  
Infrared Range ◽  
Linear Coefficient ◽  
Space Telescope ◽  
Hexagonal Close Packed ◽  
James Webb Space Telescope ◽  
Layer Deposition ◽  
Slip Planes

NASA/ESA/CSA joint venture James Webb Space Telescope is about to be launched. It is hypothesized to operate in near-infrared range. It is also hypothesized to unveil early star formation, galaxies, and universe due to its orbit, point in orbit and orbital motion. It has been under manufacturing for over 20 years at a staggering cost of 10 billion US dollars (most expensive scientific experiment in history). Beryllium (Be) is chosen to be element for construction of its main mirrors due to its high stiffness, low density, low linear coefficient of thermal expansion (α) in cryogenics and high thermal conductivity. It is followed by gold (Au) layer deposition on its (Be) surface to enhance its sensitivity towards infrared radiation as later is hypothesized to bear superior properties. However, serious mistakes have been made in selecting this material for this application. Owing to its crystal structure (hexagonal close packed (hcp)), slip planes (basal, prismatic and pyramidal) and mechanisms of their activation, Be necessitates easy fracture at cryogenic temperature. It has anisotropic properties and prone to transverse fracture under tensile loading. Furthermore, its ductile to brittle transition temperature is very low making it entirely unsuitable for such an application. It is one of most expensive metals on planet. This study constitutes revisiting these fundamental properties and mechanisms which were entirely ignored during materials selection thus rendering whole project useless.

scholarly journals MESOCYCLONE OBSERVATION BY MULTI-PARAMETER METEOROLOGICAL RADAR

2020 ◽  
pp. 9-19
Author(s):  
D.A. Denisenkov ◽  
V.Y. Zhukov ◽  
G.G. Shchukin
Keyword(s):  
Radial Velocity ◽  
Sequential Analysis ◽  
Echo Signal ◽  
Large Size ◽  
Weather Phenomenon ◽  
Meteorological Radar ◽  
The One ◽  
Differential Reflectivity ◽  
Upper Boundary ◽  
Local Speed

The article deals in detail with the case of observation of a cloud array characterized by a large (15 km) height of the upper boundary of cloud cover and the presence of areas with radar reflectivity of more than 60 dBZ by the DMRL-S meteorological radar installed in Valday (Novgorod region). Integrated application of the estimates of all measured parameters makes it possible to identify in this array the area where a rare weather phenomenon - a supercell - develops. The fact of formation of the hail area of large size is ascertained. It leads to the effect of depolarization attenuation - negative values of differential reflectivity of the echo signal of the meteorological targets. The coordinates of vertical flows are determined by analyzing data on the cross-correlation coefficient of polarization constituents of received signal. Then the obtained result is compared with the one obtained by means of estimations of the average radial velocity of particles, their much coincidence being shown. At an altitude of 5 km, areas with sharp local speed changes are observed, indicating the existence of strong vortices. Sequential analysis of the data obtained during the whole time of existence of the supercell leads to identification of a zone 5 km in diameter with a “jump” of magnitude radial velocity of particles in a layer 1 km high at a distance of 100 km. The scale of this zone, its location and the magnitudes of the parameters of the signal received from it indicate the formation of another rare weather phenomenon in it – the mesocyclone

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