Reciprocity Relations Research Articles

Ethnoecology of miriti (Mauritia flexuosa, L.f.) fruit extraction in the Brazilian Amazon: knowledge and practices of riverine peoples contribute to the biodiversity conservation

BackgroundThis article presents, from an ethnoecological perspective, the worldviews, traditional knowledge, and cultural practices of Amazonian riverine people involved in the extraction of miriti fruits (Mauritia flexuosa L.f.), in a context of increasing market demand for miriti fruits and of pressure for the intensification of açaí (Euterpe oleracea Mart.) production on the Sirituba island, in Abaetetuba, Brazil.MethodsMethods used were participant observation and non-directive interviews with 22 extractive families of miriti from the Santa Maria and Costa Sirituba communities, on Sirituba Island, in Abaetetuba, Pará, Brazil. Non-structured interviews were used to analyze the knowledge about the species, history of miriti extraction, the traditions, and innovations related to this activity over time. Participant observation took place when riverine individuals were working with miriti fruits, in order to grasp the “codes” that permeate the human-nature relationships embedded in this production system.ResultsIt was verified that the riverine peoples have a great knowledge about the palm tree, which is reflected in their own classification systems and management practices that allow the sustainable extraction of the fruits, avoiding, for example, cutting the miriti palms. In addition, a reciprocity relationship was observed between riverine peoples and miriti palm that are personified and preserved, contributing to the conservation of the species in the floodplain, even with the intensification of açaí (Euterpe oleracea Mart.) production. Another important aspect is the collective work involving all the members of the family, which allows the appropriation of the knowledge about the extraction of miriti by the young, allowing the resistance of the tradition that remains strong, contributing to the sustainability of the practice and conservation of biodiversity in the Amazonian floodplain.ConclusionThe k-c-p complex inherent to the riverine universe allows, even in face of the growing commercial demand for miriti fruits and the unchallenged increase in the extraction of this product, the conservation of floodplain biodiversity. Thus, we emphasize the importance of traditional knowledge and practices for biodiversity preservation, and they use them to guide public policies and natural resource management systems, aiming for sustainable ways to manage and use biodiversity.

Reciprocity of poly-Dedekind-type DC sums involving poly-Euler functions

The classical Dedekind sums appear in the transformation behavior of the logarithm of the Dedekind eta-function under substitutions from the modular group. The Dedekind sums and their generalizations are defined in terms of Bernoulli functions and their generalizations, and are shown to satisfy some reciprocity relations. In contrast, Dedekind-type DC (Daehee and Changhee) sums and their generalizations are defined in terms of Euler functions and their generalizations. The purpose of this paper is to introduce the poly-Dedekind-type DC sums, which are obtained from the Dedekind-type DC sums by replacing the Euler function by poly-Euler functions of arbitrary indices, and to show that those sums satisfy, among other things, a reciprocity relation.

Representation theorem for viscoelastic waves with a non-symmetric stiffness matrix

In an elastic medium, it was proved that the stiffness tensor is symmetric with respect to the exchange of the first pair of indices and the second pair of indices, but the proof does not apply to a viscoelastic medium. In this paper, we thus derive the representation theorem for viscoelastic waves in a medium with a non-symmetric stiffness matrix. The representation theorem expresses the wave field at a receiver, situated inside a subset of the definition volume of the viscoelastodynamic equation, in terms of the volume integral over the subset and the surface integral over the boundary of the subset. For the given medium, we define the complementary medium corresponding to the transposed stiffness matrix. We define the frequency-domain complementary Green function as the frequency-domain Green function in the complementary medium. We then derive the provisional representation theorem as the relation between the frequency-domain wave field in the given medium and the frequency-domain complementary Green function. This provisional representation theorem yields the reciprocity relation between the frequency-domain Green function and the frequency-domain complementary Green function. The final version of the representation theorem is then obtained by inserting the reciprocity relation into the provisional representation theorem.

Fast Imaging of Sources and Scatterers in a Stratified Ocean Waveguide

In this work, we have studied the asymptotic behavior of Green's function and the reciprocity relation of the far-field pattern in the stratified ocean waveguide. Moreover, two direct sampling meth...

The uniqueness of the inverse elastic wave scattering problem based on the mixed reciprocity relation

<p style='text-indent:20px;'>This paper considers the inverse elastic wave scattering by a bounded penetrable or impenetrable scatterer. We propose a novel technique to show that the elastic obstacle can be uniquely determined by its far-field pattern associated with all incident plane waves at a fixed frequency. In the first part of this paper, we establish the mixed reciprocity relation between the far-field pattern corresponding to special point sources and the scattered field corresponding to plane waves, and the mixed reciprocity relation is the key point to show the uniqueness results. In the second part, besides the mixed reciprocity relation, a priori estimates of solution to the transmission problem with boundary data in <inline-formula><tex-math id="M1">\begin{document}$ [L^{\mathrm{q}}(\partial\Omega)]^{3} $\end{document}</tex-math></inline-formula> (<inline-formula><tex-math id="M2">\begin{document}$ 1&lt;\mathrm{q}&lt;2 $\end{document}</tex-math></inline-formula>) is deeply investigated by the integral equation method and also we have constructed a well-posed modified static interior transmission problem on a small domain to obtain the uniqueness result.

On the Reciprocity Relation in General Multiport Microwave Circuits and Errata to Vector-Short-Open-Calibration Deembedding

The matrix form of the reciprocity relationship for the ABCD matrix of a general distributed microwave circuit featuring multiple ports is revisited. The correct reciprocity relationship is used to identify mistakes previously made in the derivation of key relations in the vector-short-open-calibration (VSOC) deembedding methodology, which is commonly used for removing the effect of port discontinuities in the Method-of-Moments-based electronic design automation (EDA) models of microwave circuits, digital interconnects, and other structures. Numerical results demonstrating the impact of the incorrect reciprocity relation on the accuracy of VSOC deembedding are provided.

Highly electroluminescent and stable inorganic CsPbI2Br perovskite solar cell enabled by balanced charge transfer

• Pre-treated SnO 2 has a multifunctional effect on the crystallization of CsPbI 2 Br film. • 5-AVABr post-treatment can effectively passivate CsPbI 2 Br film surface defects. • High-performance CsPbI 2 Br PBDs are prepared by bifacial modification method. Compared to the hybrid perovskite, inorganic perovskite has potential to improve the thermal stability, but the photoelectric performance is limited by the film defect and unbalanced charge transfer. In this work, we pre-treat SnO 2 layer with fullerene-ethylenediamine derivatives (C 60 -EDA and C 70 -EDA) and post-treat the CsPbI 2 Br perovskite film using 5-aminovaleric acid hydrobromide (5-AVABr), leading to the high photovoltaic/electroluminescent (PV/EL) performance. Due to the improved film-forming property, SnO 2 :C 60 -EDA and SnO 2 :C 70 -EDA induced large-grain CsPbI 2 Br film with low defect density and superior interface connectivity. The combined pre-post treatments balance the charge transfer at N-I-P interface for injection and extraction, respectively, leading to the efficient inorganic perovskite bifunction device (PBD). The target CsPbI 2 Br device achieved a PV efficiency of 16.58% (stabilized to 16.30%) with a V oc of 1.32 ± 0.06 V in the PV mode and the EL external quantum efficiency (EQE EL ) of 6.2% in the EL mode, much higher than the control device (PV efficiency of 12.06% and EQE EL of 1.0%). Thus, we demonstrated the reciprocity relation between PV and EL modes that a great solar cell needs to be a great LED. Besides, the performance can still maintain 93% and 80% of its initial values when stored in dry air atmosphere for 65 days and heated at 85 °C for 12 days, respectively. The stable PBD has potential to utilize the solar energy more efficiently for smart power supply in the electronics.

Dynamical and current-induced Dzyaloshinskii-Moriya interaction: Role for damping, gyromagnetism, and current-induced torques in noncollinear magnets

Both applied electric currents and magnetization dynamics modify the Dzyaloshinskii-Moriya interaction (DMI), which we call current-induced DMI (CIDMI) and dynamical DMI (DDMI), respectively. We report a theory of CIDMI and DDMI. The inverse of CIDMI consists in charge pumping by a time-dependent gradient of magnetization $\partial^2 M(r,t)/\partial r\partial t$, while the inverse of DDMI describes the torque generated by $\partial^2 M(r,t)/\partial r\partial t$. In noncollinear magnets CIDMI and DDMI depend on the local magnetization direction. The resulting spatial gradients correspond to torques that need to be included into the theories of Gilbert damping, gyromagnetism, and current-induced torques (CITs) in order to satisfy the Onsager reciprocity relations. CIDMI is related to the modification of orbital magnetism induced by magnetization dynamics, which we call dynamical orbital magnetism (DOM), and spatial gradients of DOM contribute to charge pumping. We present applications of this formalism to the CITs and to the torque-torque correlation in textured Rashba ferromagnets.

Theoretical and numerical investigations of the nonlinear acoustic response of feature guided waves in a welded joint

The propagation characteristics of feature guided waves (FGWs) in topographical waveguides, such as welded joints, have been widely investigated. However, most of these investigations analyzed linear acoustic characteristics. Considering the high sensitivity of nonlinear ultrasonic techniques in the nondestructive evaluation of microscopic defects in materials, such as identifying micro-defects at an early stage, it is particularly relevant to investigate the nonlinear acoustic response of FGWs in topographical waveguides. In this paper, we use a theoretical analysis and numerical simulation to investigate the second-harmonic generation (SHG) of FGWs in a welded joint. The theoretical framework is firstly expounded based on the reciprocity relation and modal expansion with the nonlinear semi-analytical finite element (SAFE) method and perfectly matched layers. Numerical models are implemented to predict the effect of SHG of FGWs in a welded joint. Two families of FGW propagation in a welded joint are analyzed. The results obtained demonstrate that mode conversion and the cumulative effect of the generated second harmonics can be observed in the welded joint. This investigation provides new physical insights into SHG for FGW propagation.

Impact of Semiconductor Band Tails and Band Filling on Photovoltaic Efficiency Limits

The theoretical maximum efficiency of a solar cell is typically characterized by a detailed balance of optical absorption and emission for a semiconductor in the limit of unity radiative efficiency and an ideal step-function response for the density of states and absorbance at the semiconductor band edges, known as the Shockley-Queisser limit. However, real materials have non-abrupt band edges, which are typically characterized by an exponential distribution of states, known as an Urbach tail. We develop here a modified detailed balance limit of solar cells with imperfect band edges, using optoelectronic reciprocity relations. We find that for semiconductors whose band edges are broader than the thermal energy, kT, there is an effective renormalized bandgap given by the quasi-Fermi level splitting within the solar cell. This renormalized bandgap creates a Stokes shift between the onset of the absorption and photoluminescence emission energies, which significantly reduces the maximum achievable efficiency. The abruptness of the band edge density of states therefore has important implications for the maximum achievable photovoltaic efficiency.

A novel method in determining a layered periodic structure

This paper is concerned with the inverse scattering of time-harmonic waves by a penetrable structure. By applying the integral equation method, we establish the uniform L^{p}_{alpha } (1< pleq 2) estimates for the scattered and transmitted wave fields corresponding to a series of incident point sources. Based on these a priori estimates and a mixed reciprocity relation, we prove that the penetrable structure can be uniquely identified by means of the scattered field measured only above the structure induced by a countably infinite number of quasi-periodic incident plane waves.

Poly-Dedekind sums associated with poly-Bernoulli functions

Apostol considered generalized Dedekind sums by replacing the first Bernoulli function appearing in Dedekind sums by any Bernoulli functions and derived a reciprocity relation for them. Recently, poly-Dedekind sums were introduced by replacing the first Bernoulli function appearing in Dedekind sums by any type 2 poly-Bernoulli functions of arbitrary indices and were shown to satisfy a reciprocity relation. In this paper, we consider other poly-Dedekind sums that are obtained by replacing the first Bernoulli function appearing in Dedekind sums by any poly-Bernoulli functions of arbitrary indices. We derive a reciprocity relation for these poly-Dedekind sums.

Analytic continuation and reciprocity relation for collinear splitting in QCD * *Supported in part by National Natural Science Foundation of China (11975200) and the Zhejiang University Fundamental Research Funds for the Central Universities (2019QNA3005)

It is well-known that direct analytic continuation of the DGLAP evolution kernel (splitting functions) from space-like to time-like kinematics breaks down at three loops. We identify the origin of this breakdown as due to splitting functions not being analytic functions of external momenta. However, splitting functions can be constructed from the squares of (generalized) splitting amplitudes. We establish the rules of analytic continuation for splitting amplitudes, and use them to determine the analytic continuation of certain holomorphic and anti-holomorphic part of splitting functions and transverse-momentum dependent distributions. In this way we derive the time-like splitting functions at three loops without ambiguity. We also propose a reciprocity relation for singlet splitting functions, and provide non-trivial evidence that it holds in QCD at least through three loops.

Solutions of P-SV and SV-P waves in single-well imaging through reciprocity relations

Single-well imaging (SWI) is a borehole measurement technique for detecting geologic structures outside a borehole by using arrays of receivers to record the waves reflected from these structures. The asymptotic solutions of P-P, SV-SV, and SH-SH waves in SWI have been obtained, but the P-SV and SV-P waves have been ignored in previous studies. It is necessary to know when these conversion waves are large and to estimate these waves when they are not ignorable. The analytical solutions of P-SV and SV-P waves are first derived using reciprocity relations between virtual concentrated forces and acoustic sources. The analytical results agree well with finite-difference solutions for monopole and dipole sources. We have found that, for a given source-receiver offset, the detected converted waves first increase and then decrease with the increase of the source-reflector distance. The relative amplitudes of converted waves to reflected waves are larger than 20% and cannot be ignored when the ratio of source-reflector distance to source-receiver offset is smaller than four. However, when the source-reflector distance is 10 or more times the source-receiver offset and the dip angle of the reflector is smaller than 10°, the amplitudes of the converted waves are smaller than 5% of the reflected waves. Furthermore, the relative amplitudes of converted waves increase with the dip angle of the reflector. The analytical solutions of converted waves are useful for simulating SWI wavefields and checking the inversion results in field logging.

Homogenization of Porous Piezocomposites with Extreme Properties at Pore Boundaries by Effective Moduli Method

The article deals with problems on determining the effective moduli of porous piezoceramic materials with substances that have extreme properties and are deposited on the pore boundaries. The argumentation for the method of effective moduli is given. The reciprocity relation, from which the properties of effective moduli that are similar to known ones for moduli of piezoelectric materials can be obtained, is proved. It is noted that for homogenization of porous piezoelectric composites with rigid or electrode pore boundaries, it is necessary to use models for materials having extremely large moduli that are located on the pore boundaries. Using numerical calculations, anomalous properties of various effective piezoelectric moduli that are promising for practical applications of the investigated piezocomposites have been revealed.

Dimensions du Capital Social: Une Proposition Pour Le Developpement Territorial

This study proposes an instrument to evaluate territorial social capital as a collective resource, found in the cooperation, trust and reciprocity relations. The evaluation of the territorial social capital was done in three neighboring areas in southern Brazil. These territories have common cultural aspects, although they have experienced different patterns of development. The results show that the territorial social capital can be analyzed according to four factors in this order: proximity, territorial anchorage, reciprocity and collective memory. The proximity and the territorial anchorage are the most powerful factors to explain social capital in these territories.

Determining the degree of acetylation of chitin/chitosan using a SSNMR 13C method on the basis of cross polarization reciprocity relation

The degree of acetylation (DA) is an essential parameter for chitin and its derivatives, which determines the chemical and physical properties of the polymers. As a consequene, fast and accurate technique to determine DA is widely required when developing the relating materials. Herein, an improved quantitative SSNMR method of rQCPZRC, based on the cross polarization reciprocity relation, was discussed and employed for DA testing. Three chitin/chitosan samples were chosen to evaluate the performance of rQCPZRC. In comparison with quantitative DP and optimized contact time CP methods, rQCPZRC is revealed as an accurate and reliable DA testing method with relative percentage errors of less than 5%. Moreover, the experimental time of rQCPZRC for each sample is 5.5 h, notably shorter than DP of 36–85 h. Thus, our work suggests rQCPZRC as a tool for DA testing, which is capable to accomplish with high accuracy and efficiency.

Identities on poly-Dedekind sums

Dedekind sums occur in the transformation behavior of the logarithm of the Dedekind eta-function under substitutions from the modular group. In 1892, Dedekind showed a reciprocity relation for the Dedekind sums. Apostol generalized Dedekind sums by replacing the first Bernoulli function appearing in them by any Bernoulli functions and derived a reciprocity relation for the generalized Dedekind sums. In this paper, we consider the poly-Dedekind sums obtained from the Dedekind sums by replacing the first Bernoulli function by any type 2 poly-Bernoulli functions of arbitrary indices and prove a reciprocity relation for the poly-Dedekind sums.

Linear Response Theory and Entropic Fluctuations in Repeated Interaction Quantum Systems

We study Linear Response Theory and Entropic Fluctuations of finite dimensional non-equilibrium repeated interaction systems (RIS). More precisely, in a situation where the temperatures of the probes can take a finite number of different values, we prove analogs of the Green-Kubo fluctuation-dissipation formula and Onsager reciprocity relations on energy flux observables. Then we prove a Large Deviation Principle, or Fluctuation Theorem, and a Central Limit Theorem on the full counting statistics of entropy fluxes. We consider two types of non-equilibrium RIS: either the temperatures of the probes are deterministic and arrive in a cyclic way, or the temperatures of the probes are described by a sequence of i.i.d. random variables with uniform distribution over a finite set.

The fluid-solid interaction scattering problem with unknown buried objects

Abstract Consider the direct and inverse scattering problem of time harmonic acoustic waves by a two-dimensional elastic obstacle which contains an unknown impenetrable object inside. We apply the boundary integral equation method to solve the direct scattering problem. Since the obtained boundary integral system is a mixed form of scalar and vector equations, we consider the existence of the solution in the sense of a weak formulation. The factorization method is employed to solve the corresponding inverse scattering problem, that is, we try to recover the shape of the interaction surface from the knowledge of acoustic far-field patterns. With the help of a special data to pattern operator G, we can reconstruct the shape of the interaction surface by using the classical factorization method. Furthermore, a new mixed reciprocity relation is proposed to show the relation between the interior elastic field and unitary matrix 𝒮 {\mathcal{S}} .