Quasi-3D Model for Lateral Resonances on Homogeneous BAW Resonators.

Lateral modes are responsible for the in-band spurious resonances that appear on BAW resonators, degrading the in-band filter response. In this work, a fast computational method based on the transmission line matrix (TLM) method is employed to model the lateral resonances of BAW resonators. Using the precomputed dispersion curves of Lamb waves and an equivalent characteristic impedance for the TE1 mode, a network of transmission lines is used to calculate the magnitude of field distributions on the electrodes. These characteristics are specific to the stack layer configuration. The model's implementation is based on nodal Y matrices, from which particle displacement profiles are coupled to the electric domain via piezoelectric constitutive relations. Consequently, the input impedance of the resonator is obtained. The model exhibits strong agreement with FEM simulations of FBARs and SMRs, and with measurements of several SMRs. The proposed model can provide accurate predictions of resonator input impedance, which is around 200 times faster than conventional FEM.

Distributed Nonlinear Model and Fast Analysis for In-Band IMD3 Prediction of Surface Acoustic Wave Resonators.

The motivation of this work is to analyze the in-band intermodulation distortion (IMD) occurring in surface acoustic wave (SAW) devices, using a recently developed fast method based on the input-output equivalent sources (IOES). The method calculates the equivalent current sources of a given harmonic (H) or IMD, which when applied at the boundaries of any uniform nonlinear region produce the same nonlinearities as the full distributed circuit. The accuracy of the method is validated with a very simplified SAW resonator with ten digits, which is modeled by a discretized Mason-based circuit. The IOES method provides equal results to the ones obtained through harmonic balance (HB) simulations, performed by means of commercial software, being the first 1000 times faster. Once the accuracy of the method is guaranteed, it is used to analyze the measured in-band IMD3 of several lithium tantalite 42° cut leaky SAW (LSAW) resonators with different pitches and duty factors at the B66 long term evolution (LTE) frequency band. Those resonators are comprised of 100 and 20 electrode pairs for the active region and each of the reflectors, respectively, which implies the analysis of a very large distributed nonlinear problem with thousands of nonlinear local sources. The IOES method takes 35.4 s in simulating 51 frequency points, whereas this simulation is not possible using a commercial HB simulator on a general-purpose computer.

The Input-Output Equivalent Sources Method for Fast Simulations of Distributed Nonlinearities in Bulk Acoustic Wave Resonators and Filters.

This work presents a new method to analyze weak distributed nonlinear (NL) effects, with a focus on the generation of harmonics (H) and intermodulation products (IMD) in bulk acoustic wave (BAW) resonators and filters composed of them. The method consists of finding equivalent current sources [input-output equivalent sources (IOES)] at the H or IMD frequencies of interest that are applied to the boundary nodes of any layer that can contribute to the nonlinearities according to its local NL constitutive equations. The new methodology is compared with the harmonic balance (HB) analysis, by means of a commercial tool, of a discretized NL Mason model, which is the most used model for NL BAW resonators. While the computation time is drastically reduced, the results are fully identical. For the simulation of a seventh-order filter, the IOES method is around 700 times faster than the HB simulations.

Intoxicació per liti en pediatria. Importància de sospitar vies d'absorció de tòxics inusuals / Intoxicación por litio en pediatría. Importancia de las vías inusuales de absorción / Lithium poisoning in children. The importance of suspecting unusual paths for absorbing toxics

Introducció: La intoxicació per liti en pediatria és infreqüent i pot arribar a provocar greus complicacions. Observació clínica: Exposem el cas d'un nen de 35 mesos que presenta somnolència, marxa atàxica i vòmits. En l'exploració física destaca tendència a la son i marxa atàxica, i en l'otoscòpia esquerra s'observen abundants secrecions que dificulten la visualització del timpà. Es realitza tomografia axial computada cranial, que confirma la presència al conducte auditiu extern esquerre d'un cos estrany esfèric d'uns 6 mm de diàmetre i densitat metàl·lica. El cos estrany s'extreu sota anestèsia, i es constata que és una pila de botó amb signes de degradació. La litèmia confirma nivells elevats (0,2 mmol/L). Després de l'extracció del cos estrany, el pacient presenta una evolució favorable, amb remissió de la simptomatologia ad integrum. Comentaris: Davant de la clínica neurològica tòrpida no es pot obviar la possibilitat d'una intoxicació. El nostre cas clínic exemplifica aquest tipus de patologia, tenint en compte que es tracta d'una intoxicació infreqüent, tant pel tipus de tòxic, com per la via d'absorció, la localització i el temps d'evolució

Introducción: La intoxicación por litio en pediatría es infrecuente y puede llegar a producir graves complicaciones. Observación clínica: Exponemos el caso de un niño de 35 meses que presenta somnolencia, marcha atáxica y vómitos. En la exploración física destaca tendencia al sueño y marcha atáxica, y en la otoscopia izquierda se observan abundantes secreciones que dificultan la visualización del tímpano. Se realiza tomografía axial computerizada craneal, que confirma la presencia en el conducto auditivo externo izquierdo de un cuerpo extraño esférico de unos 6 mm de diámetro y densidad metálica. El cuerpo extraño se extrae bajo anestesia, y se constata que es una pila de botón con signos de degradación. La litemia confirma niveles elevados (0,2 mmol/L). Tras la extracción del cuerpo extraño, el paciente presenta una evolución favorable, con remisión de la sintomatología ad integrum. Comentarios: Ante la clínica neurológica tórpida, no se puede obviar la posibilidad de una intoxicación. Nuestro caso ejemplifica este tipo de patología, teniendo en cuenta que se trata de una intoxicación infrecuente, tanto por el tipo de tóxico, como por la localización y el tiempo de evolución

Introduction: Lithium poisoning in children is rare and can result in severe toxicity. Clinical observation: We report the case of a 35-month-old child who presented with drowsiness, unstable gait, and vomiting. Physical examination revealed somnolence and ataxia. A left otoscopy examination revealed abundant fluid in the ear canal and poor visualization of the tympanic membrane. Cranial computerized tomography reported the presence of a 6 mm round foreign body of metal density lodged in the left external auditory canal. A lithium button cell battery with signs of degradation was extracted. Laboratory evaluation showed elevated lithemia (0.2 mmol/L). Following the extraction of the foreign body, the patient showed progressive improvement, with eventual complete resolution of all signs and symptoms of lithium poisoning. Comments: Lithium poisoning should be considered in the differential diagnosis of sudden onset of non-specific neurological abnormalities. Our case exemplifies the rarity of this type of poisoning, considering the toxin, the absorption pathway, the location of the source of the poison, and the time of evolution

Metarhizium brunneum (Ascomycota; Hypocreales) Treatments Targeting Olive Fly in the Soil for Sustainable Crop Production.

Soil treatments with Metarhizium brunneum EAMa 01/58-Su strain conducted in both Northern and Southern Spain reduced the olive fly (Bactrocera oleae) population density emerging from the soil during spring up to 70% in treated plots compared with controls. A model to determine the influence of rainfall on the conidial wash into different soil types was developed, with most of the conidia retained at the first 5 cm, regardless of soil type, with relative percentages of conidia recovered ranging between 56 and 95%. Furthermore, the possible effect of UV-B exposure time on the pathogenicity of this strain against B. oleae adults coming from surviving preimaginals and carrying conidia from the soil at adult emergence was also evaluated. The UV-B irradiance has no significant effect on M. brunneum EAMa 01/58-Su pathogenicity with B. oleae adult mortalities of 93, 90, 79, and 77% after 0, 2, 4, and 6 of UV-B irradiance exposure, respectively. In a next step for the use of these M. brunneum EAMa 01/58-Sun soil treatments within a B. oleae IPM strategy, its possible effect of on the B. oleae cosmopolitan parasitoid Psyttalia concolor, its compatibility with the herbicide oxyfluorfen 24% commonly used in olive orchards and the possible presence of the fungus in the olive oil resulting from olives previously placed in contact with the fungus were investigated. Only the highest conidial concentration (1 × 108 conidia ml-) caused significant P. concolor adult mortality (22%) with enduing mycosis in 13% of the cadavers. There were no fungal propagules in olive oil samples resulting from olives previously contaminated by EAMa 01/58-Su conidia. Finally, the strain was demonstrated to be compatible with herbicide since the soil application of the fungus reduced the B. oleae population density up to 50% even when it was mixed with the herbicide in the same tank. The fungal inoculum reached basal levels 4 months after treatments (1.6 × 103 conidia g soil-1). These results reveal both the efficacy and environmental and food safety of this B. oleae control method, protecting olive groves and improving olive oil quality without negative effects on the natural enemy P. concolor.

Epicuticular Wax in Developing Olives (Olea europaea) Is Highly Dependent upon Cultivar and Fruit Ripeness.

The epicuticular wax (EW) layer is located on the surface of most plant organs. It provides the cuticle with most of its properties and is the primary barrier against biotic and abiotic stress. Despite the importance of Olea europaea cultivation, few studies have characterized the EW covering leaves and olives, which could be involved in resistance to both infection and environmental conditions. In the present study, wide-ranging screening was carried out using direct-injection electrospray ionization coupled to high-resolution mass spectrometry to analyze EW in developing olives of nine varieties. The proportions of EW fractions [wax esters (WEs), diacylglycerols, triacylglycerols (TAGs), triterpenic acids, and aldehydes] strongly depended upon the olive cultivar and, in only a few cases, were influenced by the sampling date. The specific compositions of the major fractions, WEs and TAGs, were strictly related to the cultivar, while the degree of unsaturation and chain length of the WEs evolved throughout the 4 weeks prior to the olive turning color.

Electro-thermo-mechanical model for bulk acoustic wave resonators.

We present the electro-thermo-mechanical constitutive relations, expanded up to the third order, for a BAW resonator. The relations obtained are implemented into a circuit model, which is validated with extensive linear and nonlinear measurements. The mathematical analysis, along with the modeling, allows us to identify the dominant terms, which are the material temperature derivatives and two intrinsic nonlinear terms, and explain, for the first time, all observable effects in a BAW resonator by use of a unified physical description. Moreover, the terms that are responsible for the second-harmonic generation and the frequency shift with dc voltage are shown to be the same.