Designing experiments using digital fabrication in structural dynamics

In engineering, traditional approaches aimed at teaching concepts of dynamics to engineering students include the study of a dense yet sequential theoretical development of proofs and exercises. Structural dynamics are seldom taught experimentally in laboratories since these facilities should be provided with expensive equipment such as wave generators, data-acquisition systems, and heavily wired deployments with sensors. In this paper, the design of an experimental experience in the classroom based upon digital fabrication and modeling tools related to structural dynamics is presented. In particular, all experimental deployments are conceived with low-cost, open-source equipment. The hardware includes Arduino-based open-source electronics whereas the software is based upon object-oriented open-source codes for the development of physical simulations. The set of experiments and the physical simulations are reproducible and scalable in classroom-based environments.Peer ReviewedPostprint (author's final draft

Energy Level Alignment in Organic-Organic Heterojunctions: The TTF-TCNQ Interface

The energy level alignment of the two organic materials forming the TTF-TCNQ interface is analyzed by means of a local orbital DFT calculation, including an appropriate correction for the transport energy gaps associated with both materials. These energy gaps are determined by a combination of some experimental data and the results of our calculations for the difference between the TTF_{HOMO} and the TCNQ_{LUMO} levels. We find that the interface is metallic, as predicted by recent experiments, due to the overlap (and charge transfer) between the Density of States corresponding to these two levels, indicating that the main mechanism controlling the TTF-TCNQ energy level alignment is the charge transfer between the two materials. We find an induced interface dipole of 0.7 eV in good agreement with the experimental evidence. We have also analyzed the electronic properties of the TTF-TCNQ interface as a function of an external bias voltage \Delta, between the TCNQ and TTF crystals, finding a transition between metallic and insulator behavior for \Delta~0.5 eV

Implementing a TSPC D Flip Flop as an Arbiter for a low power 10-bits 200kS/s ADC with Adaptive Conversion Cycle for High-Quality Audio Applications in 0.18um TSMC CMOS Technology

This document presents the design of an arbiter circuit for a time-based SAR-ADC. The arbiter is a TSPC D flip flop. It was designed in TSMC 0.18 µm CMOS technology with 1.8 V supply voltage. It was tested at a clock frequency of 200 KHz, but it can operate even at 100 MHz. Simulation results using the typical process parameters shown a setup time of 5.02 ps and Hold time of 51.72 ps, the TSPC D flip flop power consumption is 62.61 µW@200 KHz, and the layout area is 368.284 µm2. The simulation is performed across all PVT corners that vary from a temperature of -40 °C up to 125 °C, with a supply voltage variation from 1.62 V up to 1.98 V and the TSPC D flip flop functionality is correct.ITESO, A. C

A 0.18um CMOS TSPC D Flip Flop as an Arbiter for a low power 10-bits 200kS/s ADC with Adaptive Conversion Cycle Oriented to Audio Applications

This document presents the design of an arbiter circuit for a time-based SAR-ADC. The arbiter is a TSPC D flip flop. It was designed in TSMC 0.18 μm CMOS technology with 1.8 V supply voltage. It was tested at a clock frequency of 200 KHz, but it can operate even at 100 MHz. Simulation results using the typical process parameters shown a setup time of 5.02 ps and Hold time of 51.72 ps, the TSPC D flip flop power consumption is 62.61 μW@200 KHz, and the layout area is 368.284 μm2. The simulation is performed across all PVT corners that vary from a temperature of -40 °C up to 125 °C, with a supply voltage variation from 1.62 V up to 1.98 V and the TSPC D flip flop functionality is correct.ITESO, A. C

AIP and MEN1 mutations and AIP immunohistochemistry in pituitary adenomas in a tertiary referral center.

Background: Pituitary adenomas have a high disease burden due to tumor growth/ invasion and disordered hormonal secretion. Germline mutations in genes such as MEN1 and AIP are associated with early onset of aggressive pituitary adenomas that can be resistant to medical therapy. Aims: We performed a retrospective screening study using published risk criteria to assess the frequency of AIP and MEN1 mutations in pituitary adenoma patients in a tertiary referral center. Methods: Pituitary adenoma patients with pediatric/adolescent onset, macroadenomas occurring ≤30 years of age, familial isolated pituitary adenoma (FIPA) kindreds and acromegaly or prolactinoma cases that were uncontrolled by medical therapy were studied genetically. We also assessed whether immunohistochemical staining for AIP (AIP-IHC) in somatotropinomas was associated with somatostatin analogs (SSA) response. Results: Fifty-five patients met the study criteria and underwent genetic screening for AIP/MEN1 mutations. No mutations were identified and large deletions/duplications were ruled out using MLPA. In a cohort of sporadic somatotropinomas, low AIP-IHC tumors were significantly larger (P = 0.002) and were more frequently sparsely granulated (P = 0.046) than high AIP-IHC tumors. No significant relationship between AIP-IHC and SSA responses was seen. Conclusions: Germline mutations in AIP/MEN1 in pituitary adenoma patients are rare and the use of general risk criteria did not identify cases in a large tertiary-referral setting. In acromegaly, low AIP-IHC was related to larger tumor size and more frequent sparsely granulated subtype but no relationship with SSA responsiveness was seen. The genetics of pituitary adenomas remains largely unexplained and AIP screening criteria could be significantly refined to focus on large, aggressive tumors in young patients

Numerical validation of the incremental launching method of a steel bridge through a small-scale experimental study

The final publication is available at Springer via http://dx.doi.org/10.1007/s40799-016-0037-5This article presents an experimental and a numerical study of an incremental launching process of a steel bridge. The former is deployed in a scale-reduced laboratory,whereas the latter is performed using the finite elementmethod. The numerical simulation is based upon realistic transient boundary conditions and accurately reproduces the elastic response of the steel bridge during launching. This numerical approach is validated experimentally with the scale-reduced test performed at the laboratory. The properly validated numerical model is subsequently systematically employed as a simulation tool of the process. The proposed simulation protocol might be useful for design and monitoring purposes of steel bridges to be launched. Results concerning strains, stresses, and displacements might be inferred from the model and thus compared to field measurements obtained in situ. The conditions presented at the end of the article are potentially useful for researchers and practice engineers alike.Peer ReviewedPostprint (author's final draft