Design of Experiments Implementation towards Optimization of Power Distribution Networks

Modern computer servers require cutting edge technologies to meet their expected high performance. Among several relevant disciplines, power delivery (PD) is a key player in this regard. Efficient and reliable statistical methods to reduce cost while keeping adequate server’s performance are highly demanded from the PD perspective. This paper addresses a feasible statistical methodology based on design of experiments (DoE) for evaluating platform’s power delivery ingredients. Our methodology explores voltage regulator’s intrinsic parameters, compensation networks, non-linear compensation parameters, and the amount of bulk capacitors. Our statistical approach aims at identifying those variables with the largest impact on computer server’s PD performance, as well as optimizing them at the system level while achieving cost reduction

Proceedings of IPACK' 05 The ASME/Pacific Rim Technical Conference and Exhibition on Integration and Packaging of MEMS, NEMS, and Electronic Systems IPACK2005-73307 FULL BAND S-PARAMETER GENERATION METHODOLOGY FOR HIGH SPEED PACKAGE INTERCONNECT MODELIN G

ABSTRACT Beyond GHz operation frequency and Gb/s transfer rate bring a big challenge to high speed package interconnect designs. To make sure the product meets the specifications, signal integrity analysis has to be done carefully for critical signals before tape out for manufacturing. In order to obtain an accurate signal integrity modeling, the package interconnect must be accurately modeled. Frequency domain S-parameter has been widely used to replace the traditional package lumped model characterized by the fixed values of R, L, and C, which is no longer accurate. To facilitate the time domain analysis, equivalent circuits or behavioral macro models can be established based on the frequency domain S-parameter. In order to obtain a stable, casual and accurate time domain response, the S -parameter should be accurate in the full frequency band from DC to the interested maximum frequency. Usually full wave electromagnetic simulators are used to obtain the package S -parameter. The obtained S -parameter is very accurate in high frequency band, but unfortunately poor in low frequency band which is usually an extrapolation of the high frequency results. Improper use of such EM tools will result in wrong S-parameter, which may sometimes bring instability to the final results in a time-domain simulator based on direct convolution. The equivalent circuit synthesized from the high frequency S-parameter may also generate poor result due to lack of accurate information in the low frequency band. In this paper, we first address the theoretic al reason for the inaccurate low frequency result from the full wave electromagnetic simulators. Then we introduce a new process to generate accurate S-parameter in the full interested frequency band. In the process, the frequency band is divided into three parts, the low frequency range, middle frequency range, and the high frequency range. Skin effect phenomenon is found to be the physical explanation for the frequency band division. It is found that properly choosing EM tools in the proper frequency band is the key to get accurate full band S-parameters. KEYWORDS : HIGH SPEED INTERCONNECT, S-PARAMETER, SKIN EFFECT, PROXIMITY EFFECT INTRODUCTION With the operating frequency goes beyond GHz and the transfer rate goes up to Gb/s, accurate modeling of the total interconnect from the drivers to the receivers is required to make sure the proper work of the system without suffering from signal integrity issue. Since the signal covers a very broad frequency band, from DC to GHz and beyond, simple lumped element m odel, which is found to be good when the interconnect dimension is less than one tenth of the wavelength, is now no longer accurate enough for the interconnect modeling, like package modeling. Rather distributed elements need to be use

Evaluation of Dietary Quality Based on Intelligent Ordering System and Chinese Healthy Eating Index in College Students from a Medical School in Shanghai, China

We intended to precisely evaluate the dietary quality of male and female medical college students using canteen data from the “Intelligent Ordering System” (IOS), combined with the supplemental food frequency questionnaire (SFFQ) and the Chinese Healthy Eating Index (CHEI) in Shanghai, China, to explore the potential factors influencing dietary quality. A total of 283 college students with the average age of 24.67 ± 3.21 years and Body Mass Index of 21.46 ± 3.49 kg/m2 in the medical school were enrolled in this study, and an online questionnaire investigation was conducted to collect the general information, lifestyle behavior, and SFFQ. The dietary data of the study participants from the school canteen were exported from the IOS of the Information Office of Fudan University. The CHEI consists of 17 components and the total score is 100, with a maximum score of each component of 5 or 10. We calculated each component score of the CHEI and aggregated the total score for male and female study participants. The Chi-square test and Wilcoxon rank sum test were employed in comparing the differences between the demographic characteristics and CHEI component scores of males and females. Univariate and multiple linear regression models were employed to examine the potential influencing factors of the total CHEI score. The CHEI median score was 66.65, and the component score for total grains was relatively low. Added sugars was the most overconsumed CHEI component. There were relatively serious deficiencies, based on the CHEI component scores, in fruits, soybeans, fish and seafood, and seeds and nuts in both sexes. Females had significantly higher CHEI scores than males (68.38 versus 64.31). The scores for tubers, total vegetables, dark vegetables, fruits, fish and seafood, dairy, and red meats were significantly higher in females than in males. Influencing factors including sex, education, dietary health literacy, and amount of time spent sedentarily were significantly associated with CHEI score. Our research revealed that the overall dietary quality needs to be further improved for college students at the medical school in Shanghai, China, with low intakes of total grains, fruits, soybeans, fish and seafood, and seeds and nuts, and high intakes of added sugars. Compared with males, females showed higher diet quality and conformed more strongly with the recommended Dietary Guideline for Chinese. Education, dietary health literacy, and amount of time spent sedentarily should be noted for improving the dietary quality of college students

Association between Mobile Phone Addiction Index and Sugar-Sweetened Food Intake in Medical College Students Stratified by Sex from Shanghai, China

This study’s objective was to depict sugar-sweetened food (SSF) consumption in medical college students stratified by sex from Shanghai, China, and to explore the association between the Mobile Phone Addiction Index (MPAI) and SSF intake. The data were obtained from 1121 medical college students from the Fudan University, Shanghai, China, who took an online questionnaire investigation in December 2020. Data included demographics, the MPAI, the Nutrition Literacy Assessment Questionnaire (NLAQ), total and food expenditure per month, the International Physical Activity Questionnaire (IPAQ), and a food frequency questionnaire (carbonated beverages (CB), other sugar-based beverages (OSBB), sugar/chocolate). We evaluated the association between the MPAI and three types of SSF intake according to multivariate logistic regression analysis stratified by sex. The mean CB, OSBB, and sugar/chocolate intakes were, respectively, 65.66 mL/d, 74.20 mL/d, and 4.96 g/d in men and 30.42 mL/d, 71.48 mL/d, and 4.99 g/d in women. The MPAI was positively associated with SSF intake, regardless of sex. In men, the CB and OSBB odds ratios (ORs) were, respectively, 1.023 (95% CI: 1.004–1.042), 1.019 (95% CI: 1.001–1.038); and in women, the CB, OSBB, and sugar/chocolate ORs were, respectively, 1.026 (95% CI: 1.013–1.039), 1.020 (95% CI: 1.007–1.033), and 1.019 (95% CI: 1.006–1.032). Age, NLAQ, total expenditure, food expenditure, and total physical activity also were related to SSF intake. Age and the application capacity of the NLAQ were negatively associated with SSF intake, whereas comprehension capacity of the NLAQ, total and food expenditure, and total physical activity were positively associated with SSF intake. This study confirmed that SSF intake is widespread among medical college students from Shanghai, China, even if they have relatively high nutrition health literacy. From a public health perspective, it is necessary to reduce SSF intake in medical college students by decreasing the MPAI, controlling the total and food expenditure per month in high-consumption areas, and improving the application ability of the NLAQ. Further studies are needed to explore the MPAI and other potential factors that may influence SSF intake of college students by expanding the sample size of college students throughout China, and the causal association between them

Polyethylenimine-Grafted Cellulose Nanofibril Aerogels as Versatile Vehicles for Drug Delivery

Aerogels from polyethylenimine-grafted cellulose nanofibrils (CNFs-PEI) were developed for the first time as a novel drug delivery system. The morphology and structure of the CNFs before and after chemical modification were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). Water-soluble sodium salicylate (NaSA) was used as a model drug for the investigation of drug loading and release performance. The CNFs-PEI aerogels exhibited a high drug loading capability (287.39 mg/g), and the drug adsorption process could be well described by Langmuir isotherm and pseudo-second-order kinetics models. Drug release experiments demonstrated a sustained and controlled release behavior of the aerogels highly dependent on pH and temperature. This process followed quite well the pseudo-second-order release kinetics. Owing to the unique pH- and temperature-responsiveness together with their excellent biodegradability and biocompatibility, the CNFs-PEI aerogels were very promising as a new generation of controlled drug delivery carriers, offering simple and safe alternatives to the conventional systems from synthetic polymers

Mesoporous nanoperforators as membranolytic agents via nano- and molecular-scale multi-patterning

Abstract Plasma membrane lysis is an effective anticancer strategy, which mostly relying on soluble molecular membranolytic agents. However, nanomaterial-based membranolytic agents has been largely unexplored. Herein, we introduce a mesoporous membranolytic nanoperforators (MLNPs) via a nano- and molecular-scale multi-patterning strategy, featuring a spiky surface topography (nanoscale patterning) and molecular-level periodicity in the spikes with a benzene-bridged organosilica composition (molecular-scale patterning), which cooperatively endow an intrinsic membranolytic activity. Computational modelling reveals a nanospike-mediated multivalent perforation behaviour, i.e., multiple spikes induce nonlinearly enlarged membrane pores compared to a single spike, and that benzene groups aligned parallelly to a phospholipid molecule show considerably higher binding energy than other alignments, underpinning the importance of molecular ordering in phospholipid extraction for membranolysis. Finally, the antitumour activity of MLNPs is demonstrated in female Balb/c mouse models. This work demonstrates assembly of organosilica based bioactive nanostructures, enabling new understandings on nano-/molecular patterns co-governed nano-bio interaction

Fabrication and Characterization of Highly Porous Fe(OH)₃@Cellulose Hybrid Fibers for Effective Removal of Congo Red from Contaminated Water

Research on water purification has recently revolved around nanomaterials because of their large specific surface area. However, there are still some problems associated with the preparation, application, and recovery of nanomaterials. Herein, we report for the first time a novel approach for one-step synthesis of porous hybrid fibers (PHFs), which can be used as an effective adsorbent for dye removal from polluted water. A low-cost biopolymer cellulose was chosen as the matrix of the fibers, whereas a NaOH solution was applied as the coagulation bath for the cellulose spinning dope that contained a certain amount of FeCl₃. The obtained Fe­(OH)₃@Cellulose PHFs exhibited a multiscaled pore structure, with the in situ generated Fe­(OH)₃ nanoparticles uniformly distributed on the regenerated cellulose nanofibrous network of the fibers. These structural attributes are quite advantageous for an efficient adsorbent. The maximum Congo red removal capacity of the Fe­(OH)₃@Cellulose PHFs reached 689.65 mg/g, which was much higher than many early reported values. Importantly, the Fe­(OH)₃@Cellulose PHFs could favorably remove the dye at natural pH through filtration adsorption with excellent reusability. This approach, with the desired characteristics of simplicity, high efficiency, low cost, and being environmentally friendly, demonstrated a great potential for industrial applications