A Study on Mechanical Properties of CNT-Reinforced Carbon/Carbon Composites

Carbon/carbon composites (C/C composites) possess superior characteristics of low density, high strength, extremely low coefficient of thermal expansion, and high fatigue resistance. In carbonization process, the high-temperature pyrolysis made of carbon, hydrogen, oxygen, and other elements results in a lot of voids and cavities generated in the interior of C/C composites. Therefore, the C/C composites are densified to fill the voids by using repeated impregnation. But densification is a time-wasting and complex process, which increases production costs in the manufacturing process. In this study, the multiwall carbon nanotubes (MWNTs) were adopted as a reinforcement material for C/C composites to reduce the existence of voids or cavities and enhance the mechanical properties of C/C composites. According to the experimental results, the CNT-added C/C composite containing 1.2 wt% CNT possesses the greatest flexure strength, flexure modulus, and interlaminar shearing strength. Plus, the above-mentioned strength and modulus are increased by 23%, 19.2%, and 30%, respectively

Oncologic impact of delay between diagnosis and radical nephroureterectomy

PurposeThis study aimed to evaluate the oncological outcome of delayed surgical wait time from the diagnosis of upper tract urothelial carcinoma (UTUC) to radical nephroureterectomy (RNU).MethodsIn this multicenter retrospective study, medical records were collected between 1988 and 2021 from 18 participating Taiwanese hospitals under the Taiwan UTUC Collaboration Group. Patients were dichotomized into the early (≤90 days) and late (>90 days) surgical wait-time groups. Overall survival, disease-free survival, and bladder recurrence-free survival were calculated using the Kaplan–Meier method and multivariate Cox regression analysis. Multivariate analysis was performed using stepwise linear regression.ResultsOf the 1251 patients, 1181 (94.4%) were classifed into the early surgical wait-time group and 70 (5.6%) into the late surgical wait-time group. The median surgical wait time was 21 days, and the median follow-up was 59.5 months. Our study showed delay-time more than 90 days appeared to be associated with worse overall survival (hazard ratio [HR] 1.974, 95% confidence interval [CI] 1.166−3.343, p = 0.011), and disease-free survival (HR 1.997, 95% CI 1.137−3.507, p = 0.016). This remained as an independent prognostic factor after other confounding factors were adjusted. Age, ECOG performance status, Charlson Comorbidity Index (CCI), surgical margin, tumor location and adjuvant systemic therapy were independent prognostic factors for overall survival. Tumor location and adjuvant systemic therapy were also independent prognostic factors for disease-free survival.ConclusionsFor patients with UTUC undergoing RNU, the surgical wait time should be minimized to less than 90 days. Prolonged delay times may be associated with poor overall and disease-free survival

Multidisciplinary Taiwan consensus for the use of conventional TACE in hepatocellular carcinoma treatment

Developed in early 1980s, transarterial chemoembolization (TACE) with Lipiodol was adopted globally after large-scale randomized control trials and meta-analyses proving its effectiveness were completed. Also known as “conventional TACE” (cTACE), TACE is currently the first-line treatment for patients with unresectable intermediate stage hepatocellular carcinoma (HCC) and delivers both ischemic and cytotoxic effects to targeted tumors. Although new technology and clinical studies have contributed to a more comprehensive understanding of when and how to apply this widely-adopted therapeutic modality, some of these new findings and techniques have yet to be incorporated into a guideline appropriate for Taiwan. In addition, differences in the underlying liver pathologies and treatment practices for transcatheter embolization between Taiwan and other Asian or Western populations have not been adequately addressed, with significant variations in the cTACE protocols adopted in different parts of the world. These mainly revolve around the amount and type of chemotherapeutic agents used, the type of embolic materials, reliance on Lipiodol, and the degree of selectiveness in catheter positioning. Subsequently, interpreting and comparing results obtained from different centers in a systematic fashion remain difficult, even for experienced practitioners. To address these concerns, we convened a panel of experts specializing in different aspects of HCC treatment to devise modernized recommendations that reflect recent clinical experiences, as well as cTACE protocols which are tailored for use in Taiwan. The conclusions of this expert panel are described herein

Phenomic analysis of chronic granulomatous disease reveals more severe integumentary infections in X-Linked compared with autosomal recessive chronic granulomatous disease

BACKGROUND : Chronic granulomatous disease (CGD) is an inborn error of immunity (IEI), characterised by recurrent bacterial and fungal infections. It is inherited either in an Xlinked (XL) or autosomal recessive (AR) mode. Phenome refers to the entire set of phenotypes expressed, and its study allows us to generate new knowledge of the disease. The objective of the study is to reveal the phenomic differences between XL and AR-CGD by using Human Phenotype Ontology (HPO) terms. METHODS : We collected data on 117 patients with genetically diagnosed CGD from Asia and Africa referred to the Asian Primary Immunodeficiency Network (APID network). Only 90 patients with sufficient clinical information were included for phenomic analysis. We used HPO terms to describe all phenotypes manifested in the patients. RESULTS : XL-CGD patients had a lower age of onset, referral, clinical diagnosis, and genetic diagnosis compared with AR-CGD patients. The integument and central nervous system were more frequently affected in XL-CGD patients. Regarding HPO terms, perianal abscess, cutaneous abscess, and elevated hepatic transaminase were correlated with XL-CGD. A higher percentage of XL-CGD patients presented with BCGitis/BCGosis as their first manifestation. Among our CGD patients, lung was the most frequently infected organ, with gastrointestinal system and skin ranking second and third, respectively. Aspergillus species, Mycobacterium bovis, and Mycobacteirum tuberculosis were the most frequent pathogens to be found. CONCLUSION : Phenomic analysis confirmed that XL-CGD patients have more recurrent and aggressive infections compared with AR-CGD patients. Various phenotypic differences listed out can be used as clinical handles to distinguish XL or AR-CGD based on clinical features.The Society for Relief of Disabled Children and Jeffrey Modell Foundation.https://www.frontiersin.org/journals/immunologydm2022Paediatrics and Child Healt

Synthesis, characterization, thermal properties and flame retardance of novel phenolic resin/silica nanocomposites

[[abstract]]c2004 Elsevier - Novel phenolic/silica hybrid ceramers were synthesized by the sol-gel process. FTIR and 29Si NMR were used to characterize the structure of the hybrids. The results revealed that Q4, Q3 andT 3 are the major microstructures. That is, network structures were formed. SEM, TEM and Si mapping revealed that the hybrids were nanocomposites. The thermal properties were investigated by thermogravimetric analysis (TGA). The char yields of the hybrids increased with TEOS content. Td5 (the degradation temperature at 5% weight loss) of the hybrid that contained 20 wt.% TEOS was 290°C. The Td5 of the hybrid rose to 312°C as the TEOS content was increased to 80 wt.%. TEOS inorganic components enhance the thermal stability of the hybrids. The limiting oxygen index (L.O.I.) and the UL-94 test revealed that the hybrid ceramer possesses excellent flame retardance.[[department]]化學工程學

Preparation and Characteristics of an Environmentally Friendly Hyperbranched Flame-Retardant Polyurethane Hybrid Containing Nitrogen, Phosphorus, and Silicon

The NCO functional group of 3-isocyanatoproplytriethoxysilane (IPTS) and the OH functional group of 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phospha-phenantbrene-10-oxide (DOPO-BQ) were used to conduct an addition reaction. Following completion of the reaction, triglycidyl isocyanurate (TGIC) was introduced to conduct a ring-opening reaction. Subsequently, a sol–gel method was used to initiate a hydrolysis–condensation reaction on TGIC–IPTS–DOPO-BQ to form a hyperbranched nitrogen–phosphorous–silicon (HBNPSi) flame retardant. This flame retardant was incorporated into a polyurethane (PU) matrix to prepare a hybrid material. Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), limiting oxygen index (LOI), UV-VIS spectrophotometry, and Raman analysis were conducted to characterize the structure and analyze the transparency, thermal stability, flame retardancy, and residual char to understand the flame retardant mechanism of the prepared hybrid material. After the flame retardant was added, the maximum degradation rate decreased from −36 to −17 wt.%/min, the integral procedural decomposition temperature (IPDT) increased from 348 to 488 °C, and the char yield increased from 0.7 to 8.1 wt.%. The aforementioned results verified that the thermal stability of PU can be improved after adding HBNPSi. The LOI analysis indicated that the pristine PU was flammable because the LOI of pristine PU was only 19. When the content of added HBNPSi was 40%, the LOI value was 26; thus the PU hybrid became nonflammable

Innovative Design and Motion Analysis of a Pick-and-Place Mechanism

[[abstract]]本文研究目的在於設計與運動分析一種創新的取放機構，其成果可應用於工業用之自動化設備和冲壓製程上。我們的方法是利用一組內齒輪及一組行星齒輪，從其幾何關係中找到一組或數組齒輪組及相互間的尺寸，讓輸入為旋轉運動，輸出為一個近似方形軌跡(ASP)。然後截取軌跡的一部份，並控制輸入之伺服馬達正反轉，再搭配X-Y Table，即可構成一組「取放機構」(PPM)；為快速且方便得到數組齒輪組，乃發展一組程式軟體，使用者只要輸入一邊尺寸、軌跡圓弧與方形尖角距離以及馬達運轉速度，即可自動計算出數組可以使用的齒輪組及相關尺寸，並可顯示各組的位移、速度及加速度等運動曲線，此曲線有助於分析各種齒輪組所產生軌跡之運動特性。由於研究行星齒輪與內齒輪間的傳動，我們發現了近似方形軌跡產生的方法，以此為基礎，進而發現了近似直線、近似橢圓、近似三角形、近似五角形、近似六角形、近似七角形、近似八角形等軌跡產生的方法，並將其模組化設計，研究成果可以提供仿生機器人之步態研究和高速取放機構之應用。根據軌跡模組化的概念，我們延伸發展了共48組模組，此成果可作為機構設計、機器人設計等課程輔助教學用。此外，在行星齒輪與內齒輪之兩齒輪嚙合間，特別設計零背隙的機構裝置，研究成果將可改善自動化設備、晶圓製程、以及冲床製程等快速取放機構之高速及高精度定位問題。為證明本研究之可行性，乃實際設計出一組取放機構模組，經過實驗證明不但運動軌跡符合幾何分析與電腦模擬，速度超過2,000 mm/sec，精度可達±0.0025 mm (即±2.5μm)。而且亦可與其他機構模組結合，達成只要一顆馬達輸入就可以產生多輸出的高速高精度自動化設備[[abstract]]The purpose of this research is to propose an innovative mechanical design and kinematic analysis for a pick-and-place mechanism (PPM), which is applied to automation equipments and press fabrication industries. Our methods utilize the geometric relationship to find out a single or multiple gear pairs of internal gear and planetary gear. By employing rotation motion as input and the approximate square path (ASP) as output, a set of PPM will be constructed from intercepting some portion of the ASP if we control the servomotor to rotate in the positive or negative directions and connect with a X-Y table. In order to quickly and conveniently obtain all the possible dimensions of gear pairs, a programming software is developed. The user only input the geometric dimension, and the distance between the angularity and the arc. The computer will automatically calculate several sets of available gear pairs and their related dimensions, and the kinematic curves of displacement, velocity, and acceleration, are also displayed. The curves will be helpful to analyze all kinds of gear pairs which generate the path of motion. Due to studying the transformation of the internal gear and planetary gear, we find the method of the ASP. By using this fundamental conception, we also find the methods of generating the approximate straight, ellipse, triangle, pentagon, hexagon heptagon, and octagon paths, which can be designed into a module. The results could be applied to the gaits of the imitative robots and the high-speed PPM. According to these conceptions of path modules, we expand to an amount of 48 modules from the ASP. The results could supply the educational equipments of Mechanical Design and Robot Design. Additionally, zero backlash device is designed between two-gear meshing to improve the high-speed and high-precision positioning of the PPM in automatic equipments, wafer fabrication and press fabrication industries. To verify its performance, experiments and numerical simulations are performed and compared. We achieve the performance to be with speed 2,000 mm/sec, accuracy ±0.0025 mm. The PPM could also be combined with other mechanisms to construct new systems with only one input servomotor and multiple-output mechanisms in high-speed and high-precision automatic equipments

Design and Analysis of A Sliding-Rod Robot

[[abstract]]有桿機械手具有工件夾持、取放、移位、裝配、以及檢測等功能，在自動化設備中使用率最高。因此，本研究之目的即是針對有桿機械手之設計關鍵技術，提出一系列完整之研究。 首先，說明機械手之分類方式與其功能用途，提出12種導引機構設計法及36種組合模式應用；接著，關於浮動接頭設計，提出26種設計方法，並進行其螺牙及軸銷受力分析與實驗，藉以驗證理論分析之正確性；再者，針對夾爪機構，提出8種常用夾爪機構之功能與機構原理，並選擇5種機構進行其夾爪力之分析與實驗；最後，提出完整有桿機械手之組立步驟與其多媒體之製作。 本文研究成果，期能提供給自動化設備製造者、維修者、及設計者等技術上之參考及學校機電整合、自動控制、機構設計、機械設計、夾治具設計、快速換模等自動化相關課程之輔助教材。[[abstract]]Sliding-rod robots are used to grasp and hold objects for the purposes of movement, assembly and inspection. The sliding-rod robots are the most common used robots in the automated facilities. The purpose of this study is to investigate and analyze their actuating mechanisms including manipulator, floating joint, and gripper. In this study we focused on the design and analysis of guided mechanisms, floating joints, and gripper mechanisms and gripper forces of sliding-rod robots. We present twelve types and thirty-six assembly configurations for guided mechanism design; twenty-six types for floating joint design and their force analysis, including the stress in the gear threads and pivots; the analytical and experimental results of gripper forces for five common grippers; and multimedia-based presentation of assembly procedures for sliding-rod robots. The presented results provide a lot of design guidelines and examples for automated equipment industries. It is also an excellent engineering reference for the training courses of industrial automation, such as mechatronics, system integration, automatic control, mechanism design, mechanical system design, etc

Mechanical design and motion analysis of a pick-and-place mechanism

[[abstract]]The purpose of this research is to propose a mechanical design and kinematic analysis for a pick-and-place mechanism (PPM), which is applied to automation equipments and press fabrication industries. To obtain all the possible dimensions of gear pairs, a programming software is developed by using Visual Basic (VB) language. From the path of motion, the geometric relationship between the planetary gear and internal gear will generate an approximate square path (ASP). By intercepting some portion of this ASP and utilizing one servomotor to drive the arm of the planetary gear, a new type of PPM is designed. To verify its performance, experiments and numerical simulations of motion analyses are performed and compared. The PPM could also be combined with other mechanisms to construct new systems with one input servomotor and multiple output manipulators