Desired Intensity Research Articles

Shot peening optimization with complex decision-making tool: Multi criteria decision-making

Controlled shot peening process is performed on two independent ways: (1) Pre-shot peening of Almen strips to determine the desired intensity (2) Shot peening of the real sample with the Almen intensity obtained. Shot peening of Almen strips in the first step takes more time. This is because, the application of input parameters, also measuring arc height and controlling the Almen intensity stages have to be completed consecutively. The results influence the real sample characteristics directly. Still, the arc height measurements and the input parameters adjustment depend on technicians’ expertness. So, numerical approaches by conducting finite element modelling (FEM), ANN (artificial neural network) and RSM (response surface methodology) takes more attention growingly. For this purpose, another numerical approach, multi-criteria decision making (MCDM) methods have been developed and verified among their counterparts and also by comparing the experimental results, surface roughness and surface hardness in this study. The results show that the MCDM methods are consistent within themselves and in the context of input parameters (air pressure, shot size, peening duration) and output parameters (surface hardness, surface roughness). The Topsis approach presents consistent results with compared to both the other approaches and the experimental conditions.

3-D segmentation of lung nodules using hybrid level sets

Lung nodule segmentation in CT images and its subsequent volume analysis can help determine the malignancy status of a lung nodule. While several efficient segmentation schemes have been proposed, only a few studies evaluated the segmentation's performance for large nodules. In this research, we contribute a semi-automatic system which is capable of performing robust 3-D segmentations on both small and large nodules with good accuracy. The target CT volume is de-noised with an anisotropic diffusion filter and a region of interest is selected around the target nodule on a reference slice. The proposed model performs nodule segmentation by incorporating a mean intensity based threshold in Geodesic Active Contour model in level sets. We also devise an adaptive technique using image intensity histogram to estimate the desired mean intensity of the nodule. The proposed system is validated on both lung nodules and phantoms collected from publicly available diverse databases. Quantitative and visual comparative analysis of the proposed work with the Chan-Vese algorithm and statistic active contour model of 3D Slicer platform is also presented. The resulting mean spatial overlap between segmented nodules and reference nodules is 0.855, the mean volume bias is 0.10±0.2 ml and the algorithm repeatability is 0.060 ml. The achieved results suggest that the proposed method can be used for volume estimations of small as well as large-sized nodules.

Intensity output and effectiveness of light curing units in dental offices.

BackgroundThe aims of the study were measuring the light intensity of light curing units used in Qazvin’s dental offices, determining the relationship between the clinical age of these units and their light intensity, and identifying the reasons for repairing them.Material and MethodsIn this cross-sectional study, the output intensity of 95 light curing devices was evaluated using a radiometer. The average output intensity was divided up into four categories (less than 200, 200-299, 300-500, and more than 500 mW/cm2). In addition, a questionnaire was designed to obtain information mainly about the type, clinical age, and frequency of maintenance of the units and the reasons for fixing them. Data were analyzed using Kolmogorov-Smirnov, chi-squared, and t-tests (p< 0.05) on SPSS 24.ResultsA total of 95 light curing units were examined, with 61 (64.2%) of them being of the LED type and 34 (35.8%) of the QTH type. While average light intensity in LED units was significantly higher than in QTH devices, the two device types were not significantly different regarding desirable light intensity (i.e., ≥ 300 mw/cm2). A negative correlation was observed between clinical age and light intensity. In addition, bulb replacement in QTH devices was over three times as much as in LED units. Also, repairing QTHs was more than twice as much frequent as fixing LEDs. The most common reason for repair was the breakage of the tip of the device.ConclusionsThe light intensity of LED units is significantly higher than that of QTH devices, and the frequency of repairing in QTHs was significantly more than in LEDs. Furthermore, light intensity decreases with aging, and dentists should regularly monitor the conditions of light units. Key words:Light curing unit, radiometer, light intensity, dental equipment, dental offices.

Novel Stimulation Paradigms with Temporally-Varying Parameters to Reduce Synchronous Activity at the Onset of High Frequency Stimulation in Rat Hippocampus.

Deep brain stimulation (DBS) has shown wide applications for treating various disorders in the central nervous system by using high frequency stimulation (HFS) sequences of electrical pulses. However, upon the onset of HFS sequences, the narrow pulses could induce synchronous firing of action potentials among large populations of neurons and cause a transient phase of “onset response” that is different from the subsequent steady state. To investigate the transient onset phase, the antidromically-evoked population spikes (APS) were used as an electrophysiological marker to evaluate the synchronous neuronal reactions to axonal HFS in the hippocampal CA1 region of anesthetized rats. New stimulation paradigms with time-varying intensity and frequency were developed to suppress the “onset responses”. Results show that HFS paradigms with ramp-up intensity at the onset phase could suppress large APS potentials. In addition, an intensity ramp with a slower ramp-up rate or with a higher pulse frequency had greater suppression on APS amplitudes. Therefore, to reach a desired pulse intensity rapidly, a stimulation paradigm combining elevated frequency and ramp-up intensity was used to shorten the transition phase of initial HFS without evoking large APS potentials. The results of the study provide important clues for certain transient side effects of DBS and for development of new adaptive stimulation paradigms.

Intensity of Crossings of a Given Level by a Homogeneous Random Field

The author defines the concept of the intensity of crossings of a given level by a homogeneous field as average number of points of level surface that hit the expanding space. It is shown that irrespective of the position of the center of expanding space, the problem of finding the intensity reduces to counting the level surfaces per unit volume. The author formulates the possibility of finding the number of level surfaces as a characteristic that depends on surface generating points. A differential equation is found that relates the intensities of points of local maxima and local minima with the desired intensity of level surfaces. The accuracy of the results is verified for the stationary Gaussian process. The results completely coincide with the expression first found by Rice.

Shaping the longitudinal intensity pattern of Cartesian beams in lossless and lossy media

Several applications, such as optical tweezers and atom guiding, benefit from techniques that allow the engineering of spatial field profiles, in particular their longitudinal intensity patterns. In cylindrical coordinates, methods such as frozen waves allow an advanced control of beam characteristics, but in Cartesian coordinates there is no analogous technique. Since Cartesian beams may also be useful in applications, we develop here a method to modulate on demand the longitudinal intensity pattern of any (initially) unidimensional Cartesian beam with concentrated angular spectrum (thus encompassing all unidimensional paraxial beams) in lossless and lossy media. To this end, we write the total beam as a product of two unidimensional beams and explore the degree of freedom provided by the additional Cartesian coordinate. While in the plane where this coordinate is zero the chosen unidimensional beam keeps its structure with the additional desired intensity modulation, a sinusoidal-like oscillation appears in the direction of this variable and creates a spot whose size is tunable. Examples with Gaussian and Airy beams are presented and their corresponding experimental demonstrations in free-space are performed to show the validity of the method.

Using numerical plant models and phenotypic correlation space to design achievable ideotypes.

Numerical plant models can predict the outcome of plant traits modifications resulting from genetic variations, on plant performance, by simulating physiological processes and their interaction with the environment. Optimization methods complement those models to design ideotypes, that is, ideal values of a set of plant traits, resulting in optimal adaptation for given combinations of environment and management, mainly through the maximization of performance criteria (e.g. yield and light interception). As use of simulation models gains momentum in plant breeding, numerical experiments must be carefully engineered to provide accurate and attainable results, rooting them in biological reality. Here, we propose a multi-objective optimization formulation that includes a metric of performance, returned by the numerical model, and a metric of feasibility, accounting for correlations between traits based on field observations. We applied this approach to two contrasting models: a process-based crop model of sunflower and a functional-structural plant model of apple trees. In both cases, the method successfully characterized key plant traits and identified a continuum of optimal solutions, ranging from the most feasible to the most efficient. The present study thus provides successful proof of concept for this enhanced modelling approach, which identified paths for desirable trait modification, including direction and intensity.

Integrated Strategy for High Luminescence Intensity of Upconversion Nanocrystals

The growing applications of upconversion nanocrystals in bioimaging, therapeutics, and photonics have given rise to a demand of high quality nanocrystals with desirable luminescence intensity. Although the design of optimal nanocrystals such as core–shell nanostructures has improved the intensity, the internal links between dopant concentration balance, epitaxial growth protection, and shell thickness effect encounter a compromised situation that lacks of integrated consideration and comprehensive assessment. Here we propose an integrated strategy based on a core–shell design for the enhancement of upconversion luminescence intensity. Epitaxial protection can enable higher activator accommodation capacity in limited spatial scale, which leads to an Er3+ concentration threshold improvement in β-NaYF4 core–shell nanocrystals from 2 to 6 mol %. We further perform a comprehensive assessment of the nanocrystals with convincing performance improvement in ensemble spectroscopic intensity, upconversion quantum yi...

What is stable pain control? A prospective longitudinal study to assess the clinical value of a personalized pain goal

Background: A universal consensus regarding standardized pain outcomes does not exist. The personalized pain goal has been suggested as a clinically relevant outcome measure. Aim: To assess the feasibility of obtaining a personalized pain goal and to compare a clinically based personalized pain goal definition versus a research-based study definition for stable pain. Design: Prospective longitudinal descriptive study. Measures: The attending physician completed routine assessments, including a personalized pain goal and the Edmonton Classification System for Cancer Pain, and followed patients daily until stable pain control, death, or discharge. Stable pain for cognitively intact patients was defined as pain intensity less than or equal to desired pain intensity goal (personalized pain goal definition) or pain intensity ⩽3 (Edmonton Classification System for Cancer Pain study definition) for three consecutive days with <3 breakthroughs per day. Setting/participants: A total of 300 consecutive advanced cancer patients were recruited from two acute care hospitals and a tertiary palliative care unit. Results: In all, 231/300 patients (77%) had a pain syndrome; 169/231 (73%) provided a personalized pain goal, with 113/169 (67%) reporting a personalized pain goal ⩽3 (median = 3, range = 0–10). Using the personalized pain goal definition as the gold standard, sensitivity and specificity of the Edmonton Classification System for Cancer Pain definition were 71.3% and 98.5%, respectively. For mild (0–3), moderate (4–6), and severe (7–10) pain, the highest sensitivity was for moderate pain (90.5%), with high specificity across all three categories (95%–100%). Conclusion: The personalized pain goal is a feasible outcome measure for cognitively intact patients. The Edmonton Classification System for Cancer Pain definition closely resembles patient-reported personalized pain goals for stable pain and would be appropriate for research purposes. For clinical pain management, it would be important to include the personalized pain goal as standard practice.

Spatial light structuring using a combination of multiple orthogonal orbital angular momentum beams with complex coefficients.

Analogous to time signals that can be composed of multiple frequency functions, we use uniquely structured orthogonal spatial modes to create different beam shapes. We tailor the spatial structure by judiciously choosing a weighted combination of multiple modal states within an orthogonal orbital angular momentum (OAM) basis set, creating desired beam intensity "shapes." The weights of the OAM beams to be combined forms a Fourier pair with the spatial intensity distribution in the azimuthal direction of the resultant beam. As an example, we simulate and experimentally create various beam shapes by designing the weights of the combined OAM beams. We also find that 6× higher localized power, as compared to traditional beam combining, could be achieved by coherently combining nine orthogonal OAM beams.

Permanent knee sensorimotor system changes following ACL injury and surgery.

The cruciate ligaments are components of the knee capsuloligamentous system providing vital neurosensory and biomechanical function. Since most historical primary ACL repair attempts were unsuccessful, reconstruction has become the preferred surgery. However, an increased understanding of the efficacy of lesion-site scaffolding, innovative suturing methods and materials, and evolving use of biological healing mediators such as platelet-rich plasma and stem cells has prompted reconsideration of what was once believed to be impossible. A growing number of in vivo animal studies and prospective clinical studies are providing increasing support for this intervention. The significance of ACL repair rather than reconstruction is that it more likely preserves the native neurosensory system, entheses, and ACL footprints. Tissue preservation combined with restored biomechanical function increases the likelihood for premorbid neuromuscular control system and dynamic knee stability recovery. This recovery should increase the potential for more patients to safely return to sports at their desired intensity and frequency. This current concepts paper revisits cruciate ligament neurosensory and neurovascular anatomy from the perspective of knee capsuloligamentous system function. Peripheral and central nerve pathways and central cortical representation mapping are also discussed. Surgical restoration of a more physiologically sound knee joint may be essential to solving the osteoarthritis dilemma. Innovative rehabilitative strategies and outcome measurement methodologies using more holistic and clinically relevant measurements that closely link biomechanical and neurosensory characteristics of physiological ACL functionare discussed. Greater consideration oftask-specific patient physical function and psychobehavioral links should better delineate the true efficacy of all ACL surgical and non-surgical interventions. Level of evidence IV.

Iterative approach to solve the inverse diffraction problem under sharp focusing conditions

In this paper, we consider an iterative approach to solve the inverse diffraction problem under sharp focusing conditions. It is shown that using this approach we can obtain a complex distribution in the entrance of the focusing system that creates desired intensity distribution in the focal area. As a result of the iteration process we obtained a complex distribution of transverse components of the initial field which reminds of Laguerre---Gauss mode with radial polarization and is focused in a light spot twice smaller than the diffraction limit.

Using severity factor as a parameter to optimize krill treatment under subcritical water conditions.

The aim of this study was to optimize the conditions for subcritical water treatment of krill, as expressed with a single parameter: the severity factor (logR0). Raw krill was treated under subcritical water conditions at various logR0 values (1.54-3.75) by varying the treatment temperatures (120-180°C) and times (0-10min) in two different sizes of batch-type vessel (10 and 117mL). The logR0 value could efficiently describe changes in various properties of the obtained liquid extracts and solid residues. The most desirable shrimp-like flavor intensity and highest sensory preference were obtained for logR0 values of 2.75-3.01. The results also proved that severity factor can be used as a single parameter to control subcritical water treatment conditions in differently sized batch-type vessels to produce shrimp-like flavor extract and residue from krill.

Glue-Free Stacked Luminescent Nanosheets Enable High-Resolution Ratiometric Temperature Mapping in Living Small Animals.

In this paper, a microthermograph, temperature mapping with high spatial resolution, was established using luminescent molecules embedded ultrathin polymeric films (nanosheets), and demonstrated in a living small animal to map out and visualize temperature shift due to animal's muscular activity. Herein, we report super flexible and self-adhesive (no need of glue) nanothermosensor consisting of stacked two different polymeric nanosheets with thermosensitive (Eu-tris (dinaphthoylmethane)-bis-trioctylphosphine oxide: EuDT) and insensitive (Rhodamine 800) dyes being embedded. Such stacked nanosheets allow for the ratiometric thermometry, with which the undesired luminescence intensity shift due to focal drift or animal's z-axis displacement is eliminated and the desired intensity shift solely due to the temperature shift of the sample (living muscle) can be acquired. With the stacked luminescent nanosheets, we achieved the first-ever demonstration of video filming of chronologically changing temperature-shift distribution from the rest state to the active state of the muscles in the living animal. The polymer nanosheet engineering and in vivo microthermography presented in the paper are promising technologies to microscopically explore the heat production and heat transfer in living cells, tissues, and organisms with high spatial resolution beyond what existing thermometric technologies such as infrared thermography have ever achieved.

Evaluation of the EDR Performance in Seismic Control of Steel Structures Using Endurance Time Method

The Energy Dissipating Restraint (EDR) is a friction device which can be used to dissipate the energy introduced to a structure by a seismic event. In this paper, the performance of the structures which are outfitted with the EDR is investigated in several intensity levels by using a novel seismic analysis method, namely the Endurance Time (ET) method. By reasonably estimating the response of structures over the entire range of the desired intensity levels through each time-history analysis, this method can effectively reduce the computational cost, offering an appropriate procedure for performance-based design of structures. The EDR performance in the seismic control of steel frames is evaluated at low to high intensity levels through three case studies with various story numbers. Additionally, a comparison is made between the ET results and those of conventional time-history analysis, in which a good concordance between the two methods is observed.

Fabrication of computer-generated holograms using femtosecond laser direct writing.

We demonstrate a single-step fabrication method for computer-generated holograms based on femtosecond laser direct writing. Therefore, a tightly arranged longitudinal waveguide array is directly inscribed into a transparent material. By tailoring the individual waveguide length, the phase profile of an incident laser beam can be arbitrarily adapted. The approach is verified in common borosilicate glass by inscribing a designed phase hologram, which forms the desired intensity pattern in its far field. The resulting performance is analyzed, and the potential as well as limitations of the method are discussed.

Solving the inverse problem of focusing laser radiation in a plane region using geometrical optics

We proposed a method for calculating the eikonal function of a light field from the condition of generating a desired intensity distribution in a predetermined region of the focal plane. To improve the efficiency of solving the problem of focusing we developed a modification of a method of rectangle matching, which enables designing diffractive optical elements (DOE) intended to focus into a plane region. The novelty of our approach consists in a method of reconstructing the eikonal function from the known ray map of points on the DOE onto points in the focal plane. We presented the results of the DOE-aided focusing into a circle, a rectangle, a rhombus, and a superellipse. The simulation results showed the high quality of focusing, thus corroborating the efficiency of the proposed method. We expect to use the diffractive optical elements (DOE) for lighting the area of interest from low-flying drones used for night-time Earth remote sensing.

Evaluation and Calibration of LCoS SLM for Direct Laser Structuring with Tailored Intensity Distributions

Tailored intensity distribution enables efficient microstructuring as the maximum pulse energy of an ultrashort-pulsed laser can be applied. Dynamic adaptation of the intensity profile can be realized by holographic laser beam shaping using phase-only liquid crystal on silicon (LCoS) displays as a spatial light modulator (SLM). To achieve the desired intensity profile at the focal plane an accurate phase retardation of the SLM's liquid crystals has to be guaranteed. In this publication we present the phase calibration of three LCoS SLM from different manufacturers. Each system is evaluated for direct laser structuring applications. As one of the tested SLM show a spatially nonlinear behavior, a compensation method proposed by Engström et al. in 2013 is applied. Finally, the necessity of this phase calibration is presented and discussed by applying a squared flat-top profile.

Running electric field gratings for detection of coherent radiation

A technique for the room temperature electro-optic detection of coherent low-frequency radiation, typically in the far infrared or terahertz (THz) range, is proposed. It relies on a longitudinally running electric field grating probed by phase-matched Raman–Nath diffraction of a higher frequency wave. The expected probe wave diffracted intensity is background-free and is proportional to the desired signal intensity. As an example, we present model calculations for the probing of monochromatic THz radiation using the organic crystal 4-N,N-dymethylamino-4′-N′-methyl-stilbazolium 2,4,6-trimethylbenzenesulfonate as nonlinear optical sensor material, for which new measurements of the refractive index and absorption up to a frequency of 11 THz are presented.

Rate Pressure Product During Upper and Lower Body Ergometer Exercise

PURPOSE: Rate Pressure Product (RPP) [the product of heart rate (HR) and systolic blood pressure (SBP)] is strongly correlated with and used as a marker of myocardial oxygen demands (MVO2), with specific utility during exercise in patients with angina pectoris. Subsequently, RPP is monitored during exercise to assure that patients do not exceed their ischemic threshold. Upper and lower body ergometry have different cardiovascular responses, which may alter the RPP response to exercise. Therefore, the purpose of this investigation was to measure HR, SBP and RPP during at similar workrates during upper body and lower body ergometer exercise. METHODS: Fifteen apparently healthy men (age: 22 ± 1.5 yrs) performed incremental (25 Watts every two minutes) arm and leg ergometry on an electronically braked ergometer to volitional fatigue. HR and SBP were measured at the end of each two-minute work stage. RPP was calculated as the product of HR and SBP. A two-way repeated measures ANOVA was used to determine differences between arm and leg ergometry across work stages. RESULTS: HR was significantly greater during arm ergometry when compared to leg ergometry at higher workrates (75 and 100 W) (p<0.001). SBP increased with increasing workrates (p<0.001) but did not differ between arm and leg ergometry. RPP was greater (p=0.003) during arm ergometry at higher workloads when compared to leg ergometry. CONCLUSIONS: HR increased to a greater magnitude during arm ergometry when compared to leg ergometry, particularly during higher workrates. There was a subsequent greater increase in RPP during arm ergometry at higher workrates. Therefore, caution should be practiced when using HR to assure the desired exercise intensity across exercise modalities for patients with ischemic heart disease. Although appropriate for leg ergometry, the prescribed training heart rate may exceed the patient’s ischemic threshold during arm ergometry.