scholarly journals Conformity Check of Thickness to the Crystal Plateλ/4(λ/2)

2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
Alexander Syuy ◽  
Dmitriy Shtarev ◽  
Victor Krishtop ◽  
Natalia Kireeva
Keyword(s):  
Theoretical Model ◽  
Relative Orientation ◽  
Crystal Plate ◽  
Optical Elements ◽  
Transmitted Radiation ◽  
Crystal Analyzer ◽  
Nonmonochromatic Radiation ◽  
The Difference

This work demonstrates that if crystal plates are identical in thickness in the direction of radiation, the intensity at the output of the polarizer-crystal-crystal-analyzer system equals zero. This means that it is possible to control the difference in thickness between the reference crystal plate (e.g., plates ofλ/4orλ/2) and the examined plate by the intensity of the transmitted radiation. Further, it shows that if nonmonochromatic radiation is used, then the spectrum of radiation at the output is determined by the relative orientation of the optical elements and their sizes. The paper gives the theoretical model for calculations of profile of spectra for the number of important cases of orientation of elements.

scholarly journals A Semi-Theoretical Model for Water Condensation: Dew Used in Conservation of Earthen Heritage Sites

Water ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 52
Author(s):  
Xiang He ◽  
Sijia Wang ◽  
Bingjian Zhang
Keyword(s):  
Mass Transfer ◽  
Theoretical Model ◽  
Field Experiments ◽  
Environmental Control ◽  
Mass Transfer Process ◽  
Formation Processes ◽  
Heritage Sites ◽  
Dew Formation ◽  
The Difference ◽  
Two Parameter

Dew is a common but important phenomenon. Though water is previously considered to be a threat to earthen heritage sites, artificial dew is showing potential in relic preservation. A model of dew prediction on earthen sites will be essential for developing preventive protection methods, but studies of dew formation processes on relics are limited. In this study, a two parameter model is proposed. It makes approximations according to the features of earthen heritage sites, assuming that a thin and steady air layer exists close to the air–solid interface. This semi-theoretical model was based on calculations of the mass transfer process in the air layer, and was validated by simulations of laboratory experiments (R > 0.9) as well as field experiments. Additionally, a numerical simulation, performed by the commercial software COMSOL, confirmed that the difference between fitting parameter δ and the thickness of assumed mass transfer field was not significant. This model will be helpful in developing automatic environmental control systems for stabilizing water and soluble salts, thus enhancing preventive protection of earthen heritage sites.

Modulation instability in nonlinear chiral fiber

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Demissie Jobir Gelmecha ◽  
Ram Sewak Singh
Keyword(s):  
Theoretical Model ◽  
Numerical Simulations ◽  
Pulse Propagation ◽  
Modulation Instability ◽  
Constitutive Relations ◽  
Gain Spectrum ◽  
Circularly Polarized ◽  
Left Handed ◽  
Simulation Results ◽  
The Difference

AbstractIn this paper, the rigorous derivations of generalized coupled chiral nonlinear Schrödinger equations (CCNLSEs) and their modulation instability analysis have been explored theoretically and computationally. With the consideration of Maxwell’s equations and Post’s constitutive relations, a generalized CCNLSE has been derived, which describes the evolution of left-handed circularly polarized (LCP) and right-handed circularly polarized (RCP) components propagating through single-core nonlinear chiral fiber. The analysis of modulation instability in nonlinear chiral fiber has been investigated starting from CCNLSEs. Based on a theoretical model and numerical simulations, the difference on the modulation instability gain spectrum in LCP and RCP components through chiral fiber has been analyzed by considering loss and chirality into account. The obtained simulation results have shown that the loss distorts the sidebands of the modulation instability gain spectrum, while chirality modulates the gain for LCP and RCP components in a different manner. This suggests that adjusting chirality strength may control the loss, and nonlinearity simultaneously provides stable modulated pulse propagation.

New analysis of holophotoelastic patterns and their application

1976 ◽  
Vol 11 (1) ◽  
pp. 11-17 ◽  
Author(s):  
J Ebbeni ◽  
J Coenen ◽  
A Hermanne
Keyword(s):  
Numerical Methods ◽  
Dynamic Problems ◽  
Principal Stresses ◽  
Optical Elements ◽  
New Type ◽  
The Difference ◽  
Fringe Patterns

This paper shows that by the use of a new type of diffuser it is possible in photo-holoelasticimetry, without any addition of optical elements or particular preparation of the specimen, to record simultaneously but separately fringe patterns respectively related to the sum and the difference of the principal stresses. The value of intensity of the interfering light reaching the hologram plate is established and hence the equations of the recorded pseudoisopachic fringe patterns are given. Used successfully for the study of particular static problems, where numerical methods are very difficult or impossible, the present interferometer is also suited for dynamic problems.

scholarly journals Social Ties and the Job Search of Recent Immigrants

ILR Review ◽  
2017 ◽  
Vol 72 (2) ◽  
pp. 355-381 ◽  
Author(s):  
Deepti Goel ◽  
Kevin Lang
Keyword(s):  
Social Networks ◽  
Theoretical Model ◽  
Job Search ◽  
Social Ties ◽  
Wage Distribution ◽  
Specific Mechanism ◽  
Recent Immigrants ◽  
The Difference

This article highlights a specific mechanism through which social networks help in job search. The authors characterize the strength of a network by its likelihood of providing a job offer. Using a theoretical model, they show that the difference between wages in jobs found using networks versus those found using formal channels decreases as the network becomes stronger. The authors verify this result for recent immigrants to Canada for whom a strong network is captured by the presence of a “close tie.” Furthermore, structural estimates confirm that the presence of a close tie operates by increasing the likelihood of generating a job offer from the network rather than by altering the network wage distribution.

Frequency of Triplets and Triplet Zygosity Types among U.S. Births, 1964

1988 ◽  
Vol 37 (3-4) ◽  
pp. 299-306 ◽  
Author(s):  
Gordon Allen
Keyword(s):  
Theoretical Model ◽  
Difference Method ◽  
Age Distribution ◽  
Young Mothers ◽  
White Population ◽  
Older Mothers ◽  
Induction Of Ovulation ◽  
Artificial Induction ◽  
The Difference ◽  
The U.S

AbstractThe frequency of triplets in the U.S. white population may have reached an all-time low around 1964, at 78 sets per million deliveries. One-fourth of those were monozygotic as estimated by the difference method, or 18% by Bulmer's theoretical model. By 1983 the frequency of triplets had nearly doubled, the increase presumably occurring in dizygotic and trizygotic types. In Belgium most triplet pregnancies now result from artificial induction of ovulation, which is expected to occur mainly in older mothers. In the U.S., however, triplets have increased as much in young mothers as in older mothers, proportionally. This age distribution of the increase may be partly explained by a decrease in parity in older mothers since 1964.

The wettability and micro-equilibrium of different essence liquids to alkali-treated kapok fiber

2021 ◽  
pp. 004051752110320
Author(s):  
Liyao Cao ◽  
Yanfang Xu ◽  
Kaifang Xie ◽  
Fumei Wang ◽  
Guangbiao Xu
Keyword(s):  
Theoretical Model ◽  
Critical Role ◽  
Error Rates ◽  
Adhesion Energy ◽  
Phase Contact ◽  
Fiber Network ◽  
Kapok Fiber ◽  
Three Phase ◽  
The Difference ◽  
Kapok Fibers

Kapok fiber is a natural hollow fiber that has superior biocompatibility and biodegradability and is naturally antibacterial. Because of its unique properties, it has great potential in the application of postoperative repair dressings. The wettability and micro-equilibrium of kapok fibers play a critical role in dressing applications. In this study, the critical adhesion volume and adhesion energy of essence liquid to alkali-treated kapok fiber (AKF) were quantitatively calculated to explore the wettability and micro-equilibrium through the equilibrium wetting theory. Meanwhile, the three-phase contact line (TCL) structure was described. The results showed that the critical adhesion volumes of the three types of essence liquid for AKF were 3.45, 3.81, and 4.12 μL, respectively. Moreover, the critical volumes and low error rates derived from the equilibrium wetting theory were 3.41 μL and 1.16%, 3.99 μL and 4.51%, and 4.60 μL and 10.43%, respectively. Therefore, the critical volume of adhesion could be well calculated by the theoretical model. The average adhesive energies of essence liquid to the AKF were 0.38, 0.45, and 0.56 J, respectively, caused by the difference in liquids properties. The TCL showed a mechanical lock and bonding points at both ends because of the curvature difference and higher surface energy. These results are proposed to inspire the design of a liquid carrier of kapok fibers based on the fiber network structure.

Large Stroke Series Compliant Mechanism

2012 ◽  
Vol 490-495 ◽  
pp. 1104-1108 ◽  
Author(s):  
Ming Cai Shan ◽  
Wei Ming Wang ◽  
Shu Yuan Ma ◽  
Shuang Liu
Keyword(s):  
Theoretical Model ◽  
Maximum Stress ◽  
Compliant Mechanism ◽  
Critical Parameters ◽  
Element Analysis ◽  
Flexure Hinges ◽  
Body Model ◽  
System A ◽  
Rigid Body Model ◽  
The Difference

To increase the stroke of precision positioning system, a novel series compliant mechanism is presented which is based on elliptical flexure hinges. Pseudo-rigid-body model and energy method are applied to establish the theoretical model of stiffness and maximum stress, which are critical parameters for the large stroke compliant mechanism. The relationships are analyzed between geometric parameters of the series complaint mechanism, stiffness and maximum stress. According that, the series compliant mechanism is designed with the stroke more than 5mm and stiffness less than 3.2N/mm. The difference is less than 5% between the results of finite element analysis and theoretical model computation, which proves the correctness of the application design.

scholarly journals Comparison of Real Response and Theoretical Modeling of Pavement with Thick Asphalt Layers under Heavy Traffic Load

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Jingsong Shan ◽  
Hongmei Shao ◽  
Qiuzhong Li ◽  
Peili Sun
Keyword(s):  
Theoretical Model ◽  
Heavy Traffic ◽  
Field Tests ◽  
Fatigue Cracking ◽  
Field Measurements ◽  
Traffic Load ◽  
Theoretic Model ◽  
Static Modulus ◽  
Two Samples ◽  
The Difference

Two kinds of asphalt pavement with thick asphalt layers were used to construct two samples. In structure I, a semirigid base and graded crushed stone subbase were used. In structure II, a granular base and semirigid subbase layer were used. Responses of the two structures under traffic loads were measured using optical fiber sensors, and the differences between theoretical model results and field measurements were analyzed. Field measurements show that vertical compressive stress in structure I is larger than that in structure II. The maximum tensile strain of the asphalt layer is located at the bottom of the AC-25C layer in structure I and at the bottom of the AC-25F layer in structure II. The latter is significantly larger than the former, indicating the possibility of fatigue cracking induced by traffic load is higher in structure II. The measured tensile horizontal strain at the bottom of the semirigid layer is relatively low (<30εμ) in both structure I and structure II. In theoretical model, static modulus, dynamic modulus, and interface bonding ability are considered and theoretical responses are calculated. There are significant differences between the theoretical results and field test data. In the theoretic model, the material properties of layers and bonding status of adjacent layers all influence the results. In order to reduce the difference between the calculated and measured results, numerous material tests and field tests should be carried out.

scholarly journals Estimation of Lens Stray Light with Regard to the Incapacitation of Imaging Sensors

Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 6308
Author(s):  
Gunnar Ritt ◽  
Bastian Schwarz ◽  
Bernd Eberle
Keyword(s):  
Light Scattering ◽  
Theoretical Model ◽  
Stray Light ◽  
Optical Systems ◽  
Optical Elements ◽  
Laser Safety ◽  
Engineering Software ◽  
Commercial Off The Shelf ◽  
Generic Set ◽  
Imaging Sensors

We present our efforts on estimating light scattering characteristics from commercial off-the-shelf (COTS) camera lenses in order to deduce thereof a set of generic scattering parameters valid for a specific lens class (double Gauss lenses). In previous investigations, we developed a simplified theoretical light scattering model to estimate the irradiance distribution in the focal plane of a camera lens. This theoretical model is based on a 3-parameter bidirectional scattering distribution function (BSDF), which describes light scattering from rough surfaces of the optical elements. Ordinarily, the three scatter parameters of the BSDF are not known for COTS camera lenses, which makes it necessary to assess them by own experiments. Besides the experimental setup and the measurement process, we present in detail the subsequent data exploitation. From measurements on seven COTS camera lenses, we deduced a generic set of scatter parameters. For a deeper analysis, the results of our measurements have also been compared with the output of an optical engineering software. Together with our theoretical model, now stray light calculations can be accomplished even then, when specific scatter parameters are not available from elsewhere. In addition, the light scattering analyses also allow considering the glare vulnerability of optical systems in terms of laser safety.

Theoretical and empirical analysis of the supplier induced demand in health care market in China

2014 ◽  
Vol 4 (2) ◽  
pp. 207-220 ◽  
Author(s):  
Jun-Shan Li ◽  
Pei-Pei He ◽  
Rui-Bo He
Keyword(s):  
Health Care ◽  
Theoretical Model ◽  
Empirical Analysis ◽  
Health Care Expenditure ◽  
Integration Theory ◽  
Health Care Market ◽  
Content Type ◽  
Induced Demand ◽  
Economics Of Health ◽  
The Difference

Purpose – The purpose of this paper is to provide theoretical model about supplier-induced demand (SID) in health care market in China. Then, an empirical analysis will also be carried out according to the theoretical model above. At last, some advices will be provided in order to control or eliminate the SID in Chinese health care market. Design/methodology/approach – SID has in fact been one of the most contentious topics in the economics of health care. According to the SID theory in health economics, the theoretical model about SID in China has been provided, then, based on the co-integration theory, the empirical analysis has been brought out. Findings – The study tells that it is the reduction of government finance to hospital, not the increase of supply that is the long-term steady determinants of growth of health care expenditure and that the difference of marginal return to hospital among all kinds of services and medicines is the external factor. Originality/value – To provide theoretical model about SID in health care market in China is the main originality value.

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