DAMPING ANALYSIS TO IMPROVE THE PERFORMANCE OF SHUNT CAPACITIVE RF MEMS SWITCH

This paper describes the significance of the iterative approach and the structure damping analysis which help to get better the performance and validation of shunt capacitive RF MEMS switch. The micro-cantilever based electrostatic ally actuated shunt capacitive RF MEMS switch is designed and after multiple iterations on cantilever structure a modification of the structure is obtained that requires low actuation voltage of 7.3 V for 3 µm deformation. To validate the structure we have performed the damping analysis for each iteration. The low actuation voltage is a consequence of identifying the critical membrane thickness of 0.7 µm, and incorporating two slots and holes into the membrane. The holes to the membrane help in stress distribution. We performed the Eigen frequency analysis of the membrane. The RF MEMS switch is micro machined on a CPW transmission line with Gap-Strip-Gap (G-S-G) of 85 µm - 70 µm - 85 µm. The switch RF isolation properties are analyzed with high dielectric constant thin films i.e., AlN, GaAs, and HfO2. For all the dielectric thin films the RF MEMS switch shows a high isolation of -63.2 dB, but there is shift in the radio frequency. Because of presence of the holes in the membrane the switch exhibits a very low insertion loss of -0.12 dB

Calculation of the properties of the rotational bands of 155,157^{155,157}Gd

We reexamine the long-standing problem of the microscopic derivation of a particle-core coupling model. We base our research on the Klein-Kerman approach, as amended by D\"onau and Frauendorf. We describe the formalism to calculate energy spectra and transition strengths in some detail. We apply our formalism to the rotational nuclei $^{155,157}$Gd, where recent experimental data requires an explanation. We find no clear evidence of a need for Coriolis attenuation.Comment: 27 pages, 13 uuencoded postscript figures. Uses epsf.st

Conformal and continuous deposition of bifunctional cobalt phosphide layers on p-silicon nanowire arrays for improved solar hydrogen evolution

Vertically aligned p-silicon nanowire (SiNW) arrays have been extensively investigated in recent years as promising photocathodes for solar-driven hydrogen evolution. However, the fabrication of SiNW photocathodes with both high photoelectrocatalytic activity and long-term operational stability using a simple and affordable approach is a challenging task. Herein, we report conformal and continuous deposition of a di-cobalt phosphide (Co2P) layer on lithography-patterned highly ordered SiNW arrays via a cost-effective drop-casting method followed by a low-temperature phosphorization treatment. The as-deposited Co2P layer consists of crystalline nanoparticles and has an intimate contact with SiNWs, forming a well-defined SiNW@Co2P core/shell nanostructure. The conformal and continuous Co2P layer functions as a highly efficient catalyst capable of substantially improving the photoelectrocatalytic activity for the hydrogen evolution reaction (HER) and effectively passivates the SiNWs to protect them from photo-oxidation, thus prolonging the lifetime of the electrode. As a consequence, the SiNW@Co2P photocathode with an optimized Co2P layer thickness exhibits a high photocurrent density of -21.9 mA.cm(-2) at 0 V versus reversible hydrogen electrode and excellent operational stability up to 20 h for solar-driven hydrogen evolution, outperforming many nanostructured silicon photocathodes reported in the literature. The combination of passivation and catalytic functions in a single continuous layer represents a promising strategy for designing high-performance semiconductor photoelectrodes for use in solar-driven water splitting, which may simplify fabrication procedures and potentially reduce production costsThis work was funded by ERDF funds through the Portuguese Operational Programme for Competitiveness and Internationalization COMPETE 2020, and national funds through FCT – The Portuguese Foundation for Science and Technology, under the project “PTDC/CTM-ENE/2349/2014” (Grant Agreement No. 016660). The work is also partially funded by the Portugal-China Bilateral Collaborative Programme (FCT/21102/28/12/2016/S). L. F. Liu acknowledges the financial support of the FCT Investigator Grant (IF/01595/2014) and Exploratory Grant (IF/01595/2014/CP1247/CT0001). L. Qiao acknowledges the financial support of the Ministry of Science and Technology of China (Grant Agreement No. 2016YFE0132400).info:eu-repo/semantics/publishedVersio

Impact of adenomyosis on pregnancy rates in IVF treatment

Letter to the EditorAbstract not availableKelton Tremellen, Vamsee Thallur

Ultrasound diagnosed adenomyosis has a negative impact on successful implantation following GnRH antagonist IVF treatment

STUDY QUESTION: Does the presence of ultrasound diagnosed adenomyosis interfere with successful implantation in patients undergoing IVF treatment with GnRH antagonist ovarian stimulation? SUMMARY ANSWER: The presence of ultrasound diagnosed adenomyosis was associated with a significant reduction in successful implantation of good quality embryos in patients undergoing GnRH antagonist stimulation for IVF treatment (viable clinical pregnancy rate 23.6% versus 44.6%, P= 0.017). WHAT IS KNOWN AND WHAT THIS PAPER ADDS: There is currently no consensus regarding the impact of adenomyosis on implantation potential. Although some studies have identified alterations in the endometrial milieu in adenomyosis patients that may impact implantation, several papers have reported no associated reproductive deficit. However, these pregnancy outcome studies have primarily investigated patients undergoing long down-regulation IVF protocols, where low levels of serum estrogen (before commencing the ovarian stimulation) may inactivate the adenomyosis and potentially negate its effect on implantation. Given that the majority of fertility clinics are now moving towards the more 'patient-friendly' antagonist protocol, where patients are not placed in a hypo-estrogen state before commencing ovarian stimulation, the question of whether adenomyosis has an impact on IVF success rates in GnRH antagonist-stimulated IVF treatment needs to be examined. DESIGN: This is a retrospective cohort study of 748 patients who, between April 2010 and March 2012, underwent a screening transvaginal ultrasound to identify possible pelvic pathology before commencing their IVF treatment. From this screening group, 213 patients were eligible to be included in the study as they had no obvious underlying uterine or embryonic factors that could have interfered with successful implantation (aged ≤39 years, good quality Day 4/5 embryo for single-embryo transfer, no uterine fibroids/hydrosalpinx or endometrial polyps). PARTICIPANTS AND SETTING: There were 213 patients in a private IVF unit eligible to be included in the study, with 38 patients (17.84%) having ultrasound diagnosed adenomyosis and 175 patients having no adenomyosis on the scan. Only the first treatment cycle for each patient was included. MAIN RESULTS AND THE ROLE OF CHANCE: The adenomyosis group had a viable clinical pregnancy rate of 23.6% compared with 44.6% in the non-adenomyosis group (P =0.017). However, the median maternal age and duration of infertility of the adenomyosis group was 2 years older and 4 months greater, respectively, than that of the non-adenomyosis group. A logistic regression analysis was performed to account for these differences between the two groups, with the adjusted results still showing a statistically significant decline in viable pregnancy rate in the adenomyosis group (OR = 0.408, CI = 0.181-0.922, P =0.031 when adjusting for maternal age; OR = 0.417, CI = 0.175-0.989, P =0.047 when adjusting for duration of infertility) BIAS, CONFOUNDING AND OTHER REASONS FOR CAUTION: Given the retrospective nature of this study, there is risk of bias. This risk was minimized by having subjective variables such as embryo quality assessed by individuals not involved in the study, while strictly applying the pre-determined inclusion/exclusion criteria to all study participants. Furthermore, it is acknowledged that ultrasound is not a perfect test for the diagnosis of adenomyosis and, therefore, may underestimate the incidence of adenomyosis by misclassifying some patients with mild adenomyosis as not affected. WIDER IMPLICATIONS OF THE FINDINGS: The results of this study should be representative of outcomes for any patient undergoing a GnRH antagonist ovarian stimulation cycle for IVF since standard IVF treatment protocols were used.V. Thalluri and K.P. Tremelle

Novel General Purpose Switched Capacitor/Varactor Design Concept in RF-MEMS Technology for Emerging 5G/6G and Super-IoT Applications

The currently under-deployment 5G, as well as the future 6G and Super-IoT paradigms, is demanding and will go on demanding for high-performance, frequency agile, and reliable RF passive components, ranging from simple switches to articulated devices, phase shifters, impedance matching tuners, RF power step attenuators, filters, and so on, with pronounced characteristics of reconfigurability and/or tunability. RF-MEMS is one of the most suitable technologies able to meet these challenges, as its recent market absorption is demonstrating. In this paper, we discuss a novel design of switched capacitor/varactor entirely designed in RF-MEMS technology, optimized against a mitigation of the activation (pull-in) voltage, as well as an increase of the ON-state capacitance. In particular, multi-physical simulations are reported and discussed, after having validated the Finite Element Method (FEM) tools against experimental datasets. Moreover, physical samples are currently under fabrication and will be reported in the final paper

A Comparative Study of Diverse RF-MEMS Switch Design Concepts Experimentally Verified up to 110 GHz for Beyond-5G, 6G and Future Networks Applications

Future broad application paradigms like beyond-5G (B5G), 6G and super-Internet of things (IoT) will bring significant disruption in all the segments of the physical infrastructure ensuring such services, from the core (cloud) to the edge of the network. Substantial rearchitecting will be necessary to allow proper functioning of a highly-diversified space-air-ground-sea physical infrastructure, along with operation at frequency ranges spanning from sub-GHz, to millimeter-waves (mm-Waves), again to sub-THz (100–300 GHz) and above. In this work, we focus on the radio frequency (RF) portion of the infrastructure, and in particular on micro-relays for channel commuting and reconfiguration of passive elements. To this end, we report on high-performance and highly-miniaturized micro-switches based on microelectromechanical-systems (MEMS) technology, known as RF-MEMS. A few different design concepts of RF-MEMS-based series ohmic switches are reported, discussed and compared, with the support of finite element method (FEM) modeling and RF experimental characterization up to 110 GHz

Unprecedented strongly panchromic absorption from proton switchable iridium(III) azoimidazolate complexes

Two novel heteroleptic iridium(III) complexes bearing an aryldiazoimidazole ligand are reported. These complexes differ structurally with respect to the protonation state of the imidazole ring, but can be independently accessed by varying the synthetic conditions. Their structures have been unequivocally confirmed by X-ray crystal structure analysis, with surprising differences in the structural parameters of the two complexes. The strongly absorbing nature of the free diazoimidazole ligand is enhanced in these iridium complexes, with the protonated cationic complex demonstrating extraordinarily strong panchromic absorption up to 700 nm. The absorption profile of the deprotonated neutral complex is blue-shifted by about 100 nm and thus the interconversion between the two complexes as a function of the acidity/basicity of the environment can be readily monitored by absorption spectroscopy. Theoretical calculations reveal the origins of these markedly different absorption properties. Finally, the protonated analogue has been targeted as an acceptor material for organic photovoltaic (OPV) applications and preliminary results are reported.Publisher PDFPeer reviewe