Miracle-dz/UniFAR-FTUs huggingface dataset:
Debonding Inhibiting Mechanism of Strain Localization Plating System

AbstractRecently, a new plating system was proposed based on a strain localization mechanism for addressing the critical debonding problem in externally bonded reinforcing systems for reinforced concrete (RC) structures. The system delays or inhibits debonding by localizing the large strain of the externally bonded reinforcement in certain areas and leaving other places in a smaller strain condition to ensure that global debonding does not occur. This debonding avoidance strategy is in line with the concept of controlling a flood by channeling water away rather than blocking it. Two techniques have been used to achieve strain localization: (1) a nanotechnology called surface mechanical attrition treatment and (2) variation in the cross-sectional area of bonded reinforcement. To better understand this newly developed system, this paper presents a numerical study of RC beams strengthened with such plating systems. This study leads to a better understanding of the mechanism for inhibiting debonding and the d.
Production of papaya seedlings using differents substrates, environments and pots

In the State of Mato Grosso do Sul, the cultivation of fruits is limited of consistent information, concerning the potential for production of seedlings for field production. This work evaluated papaya seedlings biomass production in different environments, pots, and substrates in the State University of Mato Grosso do Sul, Aquidauana - MS, Brazil, from September to November, 2006. The cultivation environments were: greenhouse with low density polyethylene film; nursery with monofilament black screened; nursery with aluminized screened and nursery with straw of native coconut palm. The substrates "soil + organic compost + vermiculite", "soil + organic compost + sawdust" and "soil + organic compost + vermiculite + sawdust" filled the polyethylene bags and polystyrene trays. The experiment consisted of a completely randomized statistical analysis in split-split-plot. The environment with aluminized screened promoted the greatest biomass accumulation for the polyethylene bags. The polyethylene bag was the best pots for papaya seedlings production. The substrates containing vermiculite promoted greater biomass in polyethylene bags. The environments with aluminized screened promoted greater leaf dry mass in the three substrates compositions.
Dynamic behavior of nonlinear rolling isolation system

The linear isolator has fixed vibration frequency. When structures with these linear isolators are located near a fault, it may cause resonance and large displacement response. Hence, nonlinear isolation may avoid this situation. In this study, an eccentric nonlinear rolling isolator with a parameter, which is the eccentricity of the pin connection of the mass block (facility) to the circular isolator, is investigated. If the eccentricity is not equal to zero, the dynamic response is nonlinear rolling behavior. The equation of motion of the isolation system is derived. The frequency of the isolator increases with the eccentricity under the same initial angle. The influence of the eccentricity to the effect of isolation is scrutinized. Finally, the feasibility of the proposed isolation device is verified numerically. If the proposed isolator is designed properly, it is effective for far‐field earthquake (El Centro earthquake). Even though the linearized frequency of the proposed isolator falls into the dominant frequency range of near‐fault earthquake (Chi‐Chi earthquake), resonance can be avoided due to nonlinearity. Copyright © 2008 John Wiley & Sons, Ltd.
Application of the surface‐current method to the analysis of saturated electromagnetic devices

This paper deals with the application of the surface‐current method to the analysis of electromagnetic devices. The basics of the method are outlined and new developments involving the implementation of automated procedures for the definition of the geometry and sources, the contour subdivision according to suitable error indexes and the upgrading of the magnetic permeability to analyse saturated devices are described. As examples of application, the method is applied to the analysis of a single‐phase step motor and a linear brushless DC motor; the results are discussed and compared with the outputs of corresponding finite‐element method analyses.
Water Distribution System Analysis: Newton-Raphson Method Revisited

Looped water distribution systems are conventionally analyzed using iterative methods such as Cross, Linear, Newton-Raphson, and Gradient algorithm methods. Depending on the unknown (hydraulic head or discharge), the methods are characterized as h or Q methods. This paper focuses on the h-Newton-Raphson method, which uses the Darcy-Weisbach head loss equation. The paper presents a procedure for improving the h-Newton-Raphson iterative procedure by directly calculating the discharge of each branch by using the Swamee and Jain equation. The proposed procedure leads to a simplified algorithm and more accurate determination of the Jacobian matrix, which accelerates the convergence of the algorithm.
The role of the contact geometry in wheel–rail impact due to wheel flats: Part II

A classification of wheel flats according to the different stages of their growth is given, along with the characteristic features of the dynamic wheel–rail interaction for each category. Mathematical expressions and frequency spectra of the corresponding wheel mass trajectories are derived. Difference is made between the subcritical and the transcritical speed regime. A criterion is derived for contact loss for worn flats. Simulations show that the dynamic wheel–rail interaction is governed by the track stiffness for low train speeds or long flat lengths; for high speeds and/or short flat lengths the interaction is governed by the inertial properties of the wheel and the rail. For a given flat geometry, nonlinearities in the relationship between the impact magnitude and the train speed occur in the stiffness-dominated speed domain, whereas this relationship is approximately linear in the inertia-governed domain. In the latter domain, the impact magnitude is found to be linearly dependent upon the maximum trajectorial curvature or inversely linearly dependent on the minimum circumferential wheel tread curvature. The above relationships are valid for the subcritical speed regime, in which no contact loss occurs. Different contributions from the literature are compared with respect to the established relationship between impact magnitude and speed. Significant differences are found, due to insufficiently defined parameters and conditions. Conditions are derived for a consistent application of the so-called equivalent rail indentation in experiments with wheel flats, and the indirect strain registration method for measuring dynamic wheel–rail contact forces is reviewed.
Automated Green Building Rating System for Building Designs

AbstractAs the sustainability of building projects has become of great concern for construction professionals, a number of different green building rating systems have been developed to help ensure that building projects are designed and built using strategies intended to minimize or eliminate their impacts on the environment. In the United States, although the Leadership in Energy and Environmental Design (LEED) green building rating system has been widely accepted as the national standard for sustainable building design, its assessment of green buildings is challenging and time-consuming owing to its complicated process. Such a green building rating process could be accelerated and facilitated by using computer technology such as building information modeling (BIM), an innovative, new approach to building design, engineering, and construction management that has been widely used in the architecture, engineering, and construction industry. To enable the green building rating for a building design in BIM .
Early Prediction of Students at Risk of Failing a Face-to-Face Course in Power Electronic Systems

Early warning systems (EWSs) have proven to be useful in identifying students at risk of failing both online and conventional courses. Although some general systems have reported acceptable ability to work in modules with different characteristics, those designed from a course-specific perspective have recently provided better outcomes. Hence, the main goal of this article is to design a tailored EWS for a conventional course in power electronic circuits. For that purpose, effectiveness of some common classifiers in predicting at-risk students has been analyzed. Although slight differences in their performance have only been noticed, an ensemble classifier combining outputs from several of them has provided to be the best performer. As a major contribution, a novel weighted voting combination strategy has been proposed to exploit global information about how basic prediction algorithms perform on several time points during the semester and diverse subsets of student-related features. Predictions at five critical points have been analyzed, revealing that the end of the fourth week is the optimal time to identify students at risk of failing the course. At that moment, accuracies about 85%–90% have been reached. Moreover, several scenarios with different subsets of student-related attributes have been considered in every time point. Besides common parameters from student's background and continuous assessment, novel features estimating student's performance progression on weekly assignments have been introduced. The proposal of this set of new input variables is another key contribution, because they have allowed to improve more than 5% predictions of at-risk students at every time point.
Knudsen pump driven by a thermoelectric material

The first use of a thermoelectric material in the bidirectional operation of a gas pump using thermal transpiration has been demonstrated. The thermoelectric material maintains a higher temperature difference which favors thermal transpiration and thus increases the efficiency of gas pumping. Since the hot and cold sides of the thermoelectric material are reversible, the direction of the pump may be changed by reversing the electrical current direction. Two different pump designs are presented that illustrate some of the design tradeoffs. The pumps are characterized by measuring the pressure difference that may be generated and by measuring the flow rate in the forward and reverse directions. For a pump composed of a porous material with a pore size of 100 nm, a maximum flow rate of 0.74 cm3 min−1 and a maximum pressure of 1.69 kPa are achieved.
Acceleration Feedback-Based Active and Passive Vibration Control of Landing Gear Components

In this paper, a novel methodology is developed to absorb the vibrations of relatively large-scale aircraft structures such as landing gear components. This is accomplished using a combination of active and passive controls. A system equivalent to a Boeing 747 landing gear break rod is selected as a test bed. The expected goal of this study is to dissipate the fundamental vibration mode of the tube. A beam-type dynamic absorber and a constrained layer damping treatment are used for passive vibration control. Simulations and experimental results are provided for the dynamic absorber case. In addition, full-state feedback along with state estimation based on the “reciprocal state space” method is presented. The plant responses and estimates for both the open loop and closed loop systems are shown in simulations. An optimal controller based on acceleration measurements using piezoelectric actuators is implemented using a hardware in the loop protocol for the active vibration control of the system. The integr.
Torsional Behavior of Concrete-Filled Circular Steel Tube Columns

Concrete-filled tubes (CFTs) are columns commonly used in high-rise building construction due to their structural effectiveness. Past studies on CFT have focused primarily on uniaxial compression, bending, and eccentric compression and a few investigations have studied member behavior under combined compression and torsion. In this paper, the behavior of a circular CFT column under combined torsion and compression was theoretically investigated considering the confinement effect of the steel tube, softening of concrete, and spiral effects. Biaxial stress effects due to diagonal cracking were also considered. By incorporating these factors into the compatibility and equilibrium conditions, a basic equation to describe the torsional behavior of the entire loading history of CFT members was derived.
Integrating Green Specifications in Construction and Overcoming Barriers in Their Use

The use of green specifications as a contractual tool to promote sustainable development should be adopted in the construction industry. The definition and characteristics of green specifications are presented in conjunction with the results of a cross-sectional survey on the possible barriers to their implementation. Generally, construction stakeholders agree that environmental considerations should be included in construction specifications but their underlying motive may be simply for satisfying mandatory requirements. Among the potential barriers identified, the additional cost associated with green requirements is perceived to be the most dominant barrier, followed by possible delay and a limited pool of competent suppliers. Although the crucial barriers based on overall responses were identified, different groups of stakeholders have shown their concerns on particular barriers. Hence, their concerns should be addressed with due regard to these differences during implementation of green specification.
Population genomics of the facultatively asexual duckweed Spirodela polyrhiza

Clonal propagation allows some plant species to achieve massive population sizes quickly but also reduces the evolutionary independence of different sites in the genome. We examine genome-wide genetic diversity in Spirodela polyrhiza, a duckweed that reproduces primarily asexually. We find that this geographically widespread and numerically abundant species has very low levels of genetic diversity. Diversity at nonsynonymous sites relative to synonymous sites is high, suggesting that purifying selection is weak. A potential explanation for this observation is that a very low frequency of sex renders selection in effective. However, there is a pronounced decay in linkage disequilibrium over 40 kb, suggesting that though sex may be rare at the individual level it is not too infrequent at the population level. In addition, neutral diversity is affected by the physical proximity of selected sites, which would be unexpected if sex was exceedingly rare at the population level. The amount of genetic mixing as assessed by the decay in linkage disequilibrium is not dissimilar from selfing species such as Arabidopsis thaliana, yet selection appears to be much less effective in duckweed. We discuss alternative explanations for the signature of weak purifying selection.
Analytic Model of Specific ON-State Resistance for Superjunction MOSFETs With an Oxide Pillar

An analytical model for superjunction (SJ) MOSFETs having an oxide pillar between the n-pillar and the p-pillar is developed. Owing to the low permittivity of the oxide, a high electric field is sustained across the oxide. This reduces the parasitic depletion width within the n-pillar, thus improving the current conducting path. The advantage of this structure is particularly visible as the cell pitch is scaled down and the pillows become narrower. The use of an oxide pillar leads to 30% reduction in the specific ON-state resistance when compared to a conventional SJ for a 2- $\mu \text{m}$ cell pitch. The analytical model shows a good agreement with the simulation results.
Use of Small Samples to Predict Fatigue Lives of Field Cores

Fatigue cracking is one of the major distresses in asphalt pavements. Accurate prediction of fatigue life of asphalt pavements can be extremely important both during the design stage and for prediction of remaining service life of in-service pavements. Traditional fatigue life predictions based on bending beam tests can be costly and time-consuming. The uniaxial push–pull (tension–compression) tests run on cylindrical samples have been a novel alternative. However, the traditional sample size for the push–pull tests may prevent its use for thin in-service pavements. This paper presents the results of a study investigating the possibility of using smaller sample sizes for push–pull tests. The viscoelastic continuum damage (VECD) characteristics of regular and small-size samples are compared, and the difference is observed to be negligible. In addition, a practical fatigue life formulation is derived on the basis of VECD theory. Uniqueness of the derived fatigue life (Nf) equation, differing from previously derived VECD-based Nf equations, stems from the fact that it does not force a certain form of equation to fit the damage characteristic curve. Finally, the differences in fatigue lives of different layers of the field sections at FHWA's accelerated loading facility are investigated.
Performance Evaluation of Hybrid Technology Networking for Real-Time Monitoring in Freight Railroad Operations

Traditional Wireless Sensor Network (WSN) solutions have been deemed insufficient to address the requirements of freight railroad companies to implement real-time monitoring and control of their trains, tracks and wayside equipment. With only ZigBee-based elements, the transmission capabilities of WSN devices are limited in terms of coverage range and throughput. This leads to severe delay and congestion in the network, particularly in railroad scenarios that usually require the nodes to be arranged in linear chain-like topology. In such a multi-hop topology to communicate from one end of a train to the locomotive — and due to ZigBee’s limited communication range — data needs to be transmitted using a very high number of hops and thus generates long delays and congestion problems.To overcome this drawback, we have proposed a heterogeneous multi-hop networking approach called “Hybrid Technology Networking” (HTN). In HTN we combined Wireless Local Area Network (WLAN) technologies like WiFi, which provide improved communication range and higher data rates, with low-power communication technologies like ZigBee. This significantly reduces the number of hops required to deliver data across the network and hence solves the issues of delay and congestion, while also achieving superior enery efficiency and network lifetime. The sensor nodes are logically divided into clusters and each cluster has a WiFi “gateway”. All intra-cluster communication is achieved via IEEE 802.15. 4 and ZigBee protocols, while all inter-cluster communication utilizes WiFi protocol standards.To implement our proposed technology in railroad networks, we are designing hardware prototypes and simulation models to evaluate the functionality and performance of our HTN solution, which is designed around a dual network stack design governed by the HTN protocol. This ensures full compliance with IEEE and industry communication protocols for interoperability. Since no simulation tools that seamlessly combine both WSN and WLAN technologies in a single module exist, we wrote our own simulation environment using OPNET. In this paper, we have provided information of implementing the HTN protocol in OPNET and the simulation results for different scenarios relevant to railroad operations. These results will demonstrate the efficacy of our proposed system as well as provide the baseline data for testing the hardware devices in live networks. Under simulated traffic and channel conditions and device configurations, we observed a decrease of 77.27% in end-to-end delay and an increase of 69.70% in received data volume when using HTN compared to ZigBee-only multi-hop networks, simulated over 14 railcars in railroad-relevant scenarios.Copyright © 2013 by ASME
Research on using QQ to promote teacher-student interaction

Research on using social software to support teacher-student interaction is increasing recently, due to the powerful communication features of social software and the growing popularity of using mobile equipment in colleges and universities. This paper taking QQ (a chat tool popularly used in China) as an example, analyses the properties of teacher-student interaction, and investigates the status about using QQ to support teacher-student interaction in colleges and universities using a questionnaire and interviews. The result shows that QQ can support and improve teacher-student interaction, but the effect is not obvious. Differences exist in supporting the various properties of teacher-student interaction, among which the role of expanding the interaction range is most evident, and followed by improving the interaction number. In other interactive properties, the role of QQ is not particularly obvious.
Shaking Table Test of the Taiwanese Traditional Dieh-Dou Timber Frame

ABSTRACT This article attempts to explore the dynamic behavior of traditional Dieh-Dou timber structure under different combinations of structural forms and vertical loads. Using time-history record (TCU 084) from the Chi-Chi earthquake, two semi full-scale specimens (Symmetric and Asymmetric) were tested. Results showed that the Symmetric specimen tends to be damaged more easily and faster than the Asymmetric one. Damage pattern generally begins from the bottom Dou members and subsequently spreading upwards to the upper Dou, horizontal Gong members, and adjoining Shu members. Friction force between the contact surfaces is crucial towards the maintenance of overall structure. Increase vertical loadings have significant effect on the natural frequencies and global stiffness of the structure. Using the Single-Degree-Of-Freedom (SDOF) system, the derived stiffness is generally in good agreement with the dynamic results of both forms. This study suggests that the effects of increasing vertical loadings should be taken into consideration for future evaluation.
Arabidopsis S2Lb links AtCOMPASS-like and SDG2 activity in histone H3 Lys-4 trimethylation independently from histone H2B monoubiquitination

The functional determinants of histone H3 Lys-4 trimethylation (H3K4me3), their potential dependency on histone H2B monoubiquitination (H2Bub) and their contribution to defining transcriptional regimes are poorly defined in plant systems. Unlike in S. cerevisiae, where a single SET1 protein catalyzes H3 Lys-4 trimethylation as part of COMPASS (COMPlex of proteins ASsociated with Set1), in Arabidopsis thaliana this activity involves multiple histone methyltransferases (HMTs). Among these, the plant-specific SDG2 (SET DOMAIN GROUP2) has a prominent role. We report that SDG2 co-regulates hundreds of genes with SWD2-like b (S2Lb), a plant ortholog of the Swd2 axillary subunit of yeast COMPASS. S2Lb co-purifies with the AtCOMPASS core subunit WDR5 from a high-molecular weight complex, and both S2Lb and SDG2 directly influence H3K4me3 enrichment over highly transcribed genes. S2Lb knockout triggers pleiotropic developmental phenotypes at the vegetative and reproductive stages, including reduced fertility and seed dormancy. Notwithstanding, s2lb seedlings display little transcriptomic defects as compared to the large repertoire of genes targeted by S2Lb, SDG2 or H3 Lys-4 trimethylation, suggesting that H3K4me3 enrichment is important for optimal gene induction during cellular transitions rather than for determining on/off transcriptional status. Moreover, unlike in budding yeast, most of the S2Lb and H3K4me3 genomic distribution does not rely on a trans-histone crosstalk with histone H2B monoubiquitination. Collectively, this study unveils that the evolutionarily conserved COMPASS-like complex has been coopted by the plant-specific SDG2 HMT and mediates H3K4me3 deposition through an H2Bub-independent pathway in Arabidopsis.