Physics in the Garden

The Final Design Review (FDR) report explains the initial research, design process, finalized design, manufacturing and assembly methods, and testing done by the senior project group in Mechanical Engineering Department at California Polytechnic State University, San Luis Obispo. For this project, the San Luis Obispo Botanical Garden would like to develop an educational and interactive exhibit that conveys a lesson in physics. The Botanical Garden envisions an exciting feature to educate children on physical science and broaden the appeal of the garden. This document captures the problem’s scope, requirements, initial concept, design research, target demographic, ideation, evaluation processes, and project timeline. The evaluation process includes Weighted Decision Matrices, which led to the final concept design. The final design and justifications for each component explains why each material and design were chosen. The manufacturing plan describes how each component and assembly will be produced. The design verification plan shows various tests to ensure safety, ease of maintenance, and longevity. Our team’s final design is a gearbox, which demonstrates how gear size and ratio affect gear speed, along with how gears are commonly used in everyday objects. The included project Gantt Chart displays major milestones that were met throughout this project

Common Sites, Etiology, and Solutions of Persistent Septal Deviation in Revision Septoplasty

Objectives To investigate the common causes of persistent septal deviation in revision septoplasty and to report the surgical techniques and results to correct them. Methods A total of 100 consecutive patients (86 males) who had revision septoplasty due to persistent septal deviation from 2008 and 2014 were included in the study. Their mean age was 35.6 years and the mean follow-up duration was 9.1 months. Presenting symptoms, sites of persistent septal deviation, techniques used to correct the deviation, and surgical results were reviewed. Results The mean interval between primary and revision surgery was 6.2 years. Forty-eight patients received revision septoplasty and 52 received revision septoplasty combined with rhinoplasty. Nasal obstruction was the most presenting symptom in almost all patients. The most common site of persistent septal deviation was middle septum (58%) followed by caudal septum (31%). Correcting techniques included further chondrotomy and excision of deviated portion in 76% and caudal batten graft in 39%. Rhinoscopic and endoscopic exams showed straight septum in 97% and 92 patients had subjective symptom improvement postoperatively. Conclusion Middle septum and caudal septum were common sites of persistent deviation. Proper chondrotomy with excision of deviated middle septum and correction of the caudal deviation with batten graft are key maneuvers to treat persistent deviation

Performance of a lead rubber damper under cyclic shear loading and its applicability to a full-scale structure

In this paper, we investigate the performance of a new lead rubber damper (LRD) and its applicability to a full-scale structure. This device is more advanced than existing lead-rubber based isolation devices. In contrast to the existing devices, multiple lead cores are installed in the LRD in order to enhance the performance of the laminated rubber and lead. It is able to perform effectively under the application of shear force. An experiment was performed to investigate its dependency on the level of shear strain and frequency. The applicability of this new device to a full-scale structure is also examined by performing a vibration test on a five floor modal-test tower

Lattice-patterned LC-polymer composites containing various nanoparticles as additives

In this study, we show the effect of various nanoparticle additives on phase separation behavior of a lattice-patterned liquid crystal [LC]-polymer composite system and on interfacial properties between the LC and polymer. Lattice-patterned LC-polymer composites were fabricated by exposing to UV light a mixture of a prepolymer, an LC, and SiO2 nanoparticles positioned under a patterned photomask. This resulted in the formation of an LC and prepolymer region through phase separation. We found that the incorporation of SiO2 nanoparticles significantly affected the electro-optical properties of the lattice-patterned LC-polymer composites. This effect is a fundamental characteristic of flexible displays. The electro-optical properties depend on the size and surface functional groups of the SiO2 nanoparticles. Compared with untreated pristine SiO2 nanoparticles, which adversely affect the performance of LC molecules surrounded by polymer walls, SiO2 nanoparticles with surface functional groups were found to improve the electro-optical properties of the lattice-patterned LC-polymer composites by increasing the quantity of SiO2 nanoparticles. The surface functional groups of the SiO2 nanoparticles were closely related to the distribution of SiO2 nanoparticles in the LC-polymer composites, and they influenced the electro-optical properties of the LC molecules. It is clear from our work that the introduction of nanoparticles into a lattice-patterned LC-polymer composite provides a method for controlling and improving the composite's electro-optical properties. This technique can be used to produce flexible substrates for various flexible electronic devices

A simple iterative independent component analysis algorithm for vibration source signal identification of complex structures

ABSTRACT:Independent Component Analysis (ICA), one of the blind source separation methods, can be applied for extracting unknown source signals only from received signals. This is accomplished by finding statistical independence of signal mixtures and has been successfully applied to myriad fields such as medical science, image processing, and numerous others. Nevertheless, there are inherent problems that have been reported when using this technique: insta- bility and invalid ordering of separated signals, particularly when using a conventional ICA technique in vibratory source signal identification of complex structures. In this study, a simple iterative algorithm of the conventional ICA has been proposed to mitigate these problems. The proposed method to extract more stable source signals having valid order includes an iterative and reordering process of extracted mixing matrix to reconstruct finally converged source signals, referring to the magnitudes of correlation coefficients between the intermediately separated signals and the signals measured on or nearby sources. In order to review the problems of the conventional ICA technique and to vali- date the proposed method, numerical analyses have been carried out for a virtual response model and a 30m class submarine model. Moreover, in order to investigate applicability of the proposed method to real problem of complex structure, an experiment has been carried out for a scaled submarine mockup. The results show that the proposed method could resolve the inherent problems of a conventional ICA technique

Portulaca oleracea Ameliorates Diabetic Vascular Inflammation and Endothelial Dysfunction in db/db Mice

Type 2 diabetes is associated with significantly accelerated rates of micro- and macrovascular complications such as diabetic vascular inflammation and endothelial dysfunction. In the present study, we investigated the protective effect of the aqueous extract of Portulaca oleracea L. (AP), an edible plant used as a folk medicine, on diabetic vascular complications. The db/db mice were treated with AP (300 mg/kg/day, p.o.) for 10 weeks, and AP treatment markedly lowered blood glucose, plasma triglyceride, plasma level of LDL-cholesterol, and systolic blood pressure in diabetic db/db mice. Furthermore, AP significantly increased plasma level of HDL-cholesterol and insulin level. The impairment of ACh- and SNP-induced vascular relaxation of aortic rings were ameliorated by AP treatment in diabetic db/db mice. This study also showed that overexpression of VCAM-1, ICAM-1, E-selectin, MMP-2, and ET-1 were observed in aortic tissues of untreated db/db mice, which were significantly suppressed by treatment with AP. We also found that the insulin immunoreactivity of the pancreatic islets remarkably increased in AP treated db/db mice compared with untreated db/db mice. Taken together, AP suppresses hyperglycemia and diabetic vascular inflammation, and prevents the development of diabetic endothelial dysfunction for the development of diabetes and its vascular complications