Miracle-dz/UniFAR-FTUs huggingface dataset:
Boost-buck inverter variable structure control for grid-connected photovoltaic systems with sensorless MPPT

The present work describes the analysis, modeling and control of a transformerless boost-buck power inverter used as a DC-AC power conditioning stage for grid-connected photovoltaic (PV) systems. The power conditioning system's control scheme includes a variable structure controller to assure output unity power factor and a sensorless maximum power point tracking (MPPT) algorithm to optimize the PV energy extraction. To maximize the steady-state input-output energy transfer ratio a discrete linear controller is designed from a large-signal sampled data model of the system. The achievement of the DC-AC conversion at unity power factor and the efficient PVs energy extraction are validated with simulation results.
Trends in Susceptibility to Aggressive Periodontal Disease

Aggregatibacter actinomycetemcomitans is a gram-negative microbe involved in periodontitis. Strains with varying degrees of virulence have been identified, in healthy and periodontally compromised individuals alike. Hosts mount differential immune responses to its various serotypes and virulence factors. Studies have explored host immune response in terms of antibody titers, leukocyte responses, and specific inflammatory mediators, questioning the ways in which the infectious microorganism survives. This mini-review will identify the key themes in immune response patterns of individuals both affected by and free from aggressive periodontal disease, thereby using it to understand various forms of periodontitis.
Links between the Brain and Retina: The Effects of Cigarette Smoking-Induced Age-Related Changes in Alzheimer’s Disease and Macular Degeneration

Citation: Yu SS, Tang X, Ho Y-S, Chang RC-C and Chiu K (2016) Links between the Brain and Retina: The Effects of Cigarette Smoking-Induced Age-Related Changes in Alzheimer’s Disease and Macular Degeneration. Front. Neurol. 7:119. doi: 10.3389/fneur.2016. 00119 Links between the Brain and Retina: The Effects of Cigarette Smoking-induced Age-Related Changes in Alzheimer’s Disease and Macular Degeneration
Quantification and Classification of E. coli Proteome Utilization and Unused Protein Costs across Environments

The costs and benefits of protein expression are balanced through evolution. Expression of un-utilized protein (that have no benefits in the current environment) incurs a quantifiable fitness costs on cellular growth rates; however, the magnitude and variability of un-utilized protein expression in natural settings is unknown, largely due to the challenge in determining environment-specific proteome utilization. We address this challenge using absolute and global proteomics data combined with a recently developed genome-scale model of Escherichia coli that computes the environment-specific cost and utility of the proteome on a per gene basis. We show that nearly half of the proteome mass is unused in certain environments and accounting for the cost of this unused protein expression explains >95% of the variance in growth rates of Escherichia coli across 16 distinct environments. Furthermore, reduction in unused protein expression is shown to be a common mechanism to increase cellular growth rates in adaptive evolution experiments. Classification of the unused protein reveals that the unused protein encodes several nutrient- and stress- preparedness functions, which may convey fitness benefits in varying environments. Thus, unused protein expression is the source of large and pervasive fitness costs that may provide the benefit of hedging against environmental change.
MU-MIMO precoding for VLC with imperfect CSI

This paper investigates the performance of different precoding schemes for a multi-user MIMO VLC system with channel estimation errors, an assumption that is commonly neglected in the literature. In particular, dirty paper coding, channel inversion, and block diagonalization, are considered for interference mitigation under imperfect channel state information. The impact of the variation of the beam angles of the transmitters and the field of view (FOV) of the receivers on the system performance is also examined. Simulation results reveal that, dirty paper coding provides the best performance under perfect channel state information (CSI). However, under imperfect CSI, suboptimal linear precoding schemes will give better performance. Furthermore, tuning the transmitting angles and the FOVs can significantly improve the system performance.
Mechanical response of TiAl6V4 lattice structures manufactured by selective laser melting in quasistatic and dynamic compression tests

This paper focusses on the investigation of the mechanical properties of lattice structures manufactured by selective laser melting using contour-hatch scan strategy. The motivation for this research is the systematic investigation of the elastic and plastic deformation of TiAl6V4 at different strain rates. To investigate the influence of the strain rate on the mechanical response (e.g., energy absorption) of TiAl6V4 structures, compression tests on TiAl6V4-lattice structures with different strain rates are carried out to determine the mechanical response from the resulting stress-strain curves. Results are compared to the mechanical response of stainless steel lattice structures (316L). It is shown that heat-treated TiAl6V4 specimens have a larger breaking strain and a lower drop of stress after failure initiation. Main finding is that TiAl6V4 lattice structures show brittle behavior and low energy absorption capabilities compared to the ductile behaving 316L lattice structures. For larger strain rates, ultimate tensile strength of TiAl6V4 structures is more than 20% higher compared to lower strain rates due to cold work hardening.
Damage Assessment in a Cracked Fiber-Reinforced Cantilever Beam Using Wavelet-Kurtosis Techniques

In the last decades the use of composite materials has increased especially in light-weight structural applications, such as wind turbine blades. These structural components require reliable methods for damage assessment to avoid progressive or sudden and catastrophic failures. In this paper, a model of a fiber-reinforced composite cantilever beam with a bridged edge crack, representing an existing damage state, is considered. The composite matrix of the beam exhibits a linear-elastic behavior, whereas a fracture mechanics-based theoretical model incorporating the crack bridging forces in the fiber-reinforcement is used to describe the elastic-plastic response of the cracked beam section subjected to bending moment. This model is employed to simulate the nonlinear static deflection of cantilever beams with different crack locations and depths. Wavelet and kurtosis-based identification techniques are employed in the localization and calibration of this damage in presence of noise. The influence of the bridging effect of the fibers on the success of the damage assessment is discussed.
Synchronous Reference Frame Hysteresis Current Control for Grid Converter Applications

This paper investigates the operation of space-vector-based hysteresis current control in the synchronous reference frame (SRF) for grid-connected voltage source converters. The space-vector-based approach allows for the systematic application of zero-voltage vectors and prevents high switching frequencies caused by phase interaction. The average switching frequency can be minimized by always selecting the zero-voltage vector that is closest to the previous switching state. Implementation in the SRF ensures a simple structure based on two three-level hysteresis comparators and a switching table that fits well into the traditional structure of vector-oriented current control. For operation in a grid-connected converter with an LCL filter, the current references to the hysteresis controllers are given by a dc-link voltage controller and an active damping mechanism for suppressing filter oscillations. Results from simulations and laboratory experiments are presented to illustrate the features of the investigated approach compared to traditional phase-current hysteresis controllers.
Light-scattering capacity of ethylene–vinyl acetate copolymers in polypropylene: Toward high haze and transmittance

Light-scattering materials were fabricated by the melt blending of polypropylene with an ethylene–vinyl acetate copolymer (EVA) to prevent the glare effect of light-emitting diodes. The results show that the light-scattering capacity was remarkably dependent on the phase morphologies of EVA. (1) When EVA was dispersed as spherical droplets, the transmittance and haze gradually increased with the enrichment of EVA, and the half-peak width of the light-scattering pattern reached a maximum when 30 wt % EVA was loaded. On the basis of the analysis of Mie scattering theory, the enlargement of scattering particles promoted light transmittance, and more incoming light was deflected at the arclike interfaces. This induced a distinct antiglare effect. (2) When scattering particles deformed and expanded vertically in the light-transmitting direction, the light-scattering capacity turned out to be weakened by further enrichment of the EVA phase. The planelike interfaces reduced the deflection of incoming light, and this led to decreases in the scattering angles. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42844.
Commensurability and locally free Kleinian groups

We show that there exist infinitely many commensurability classes of finite volume hyperbolic 3-manifolds whose fundamental group contains a subgroup which is locally free but not free. The main technical tool is the fact that a collection of hyperbolic 3-manifolds of bounded volume contains infinitely many commensurability classes. The result then by an application of Thurston's hyperbolization theorem for Haken 3-manifolds.
An active clamping current-fed half-bridge converter for fuel-cell generation systems

In this paper, a new active clamping current-fed half-bridge converter has been proposed, which is suitable for fuel cell based power generation systems. The proposed converter has outstanding advantages over the conventional dc-dc converters with respect to high efficiency, high power density, and high component utilization. In special, the proposed converter has predominant high boosting output voltage and high efficiency characteristics under the inherently severe low output voltage of the fuel cell through the overall load conditions. Moreover, the developed converter has been experimentally tested with the help of a fuel cell simulator, which is developed by Sungkyunkwan Univ. and can generate the V-I characteristics of polymer electrolyte membrane fuel cell (PEMFC), so that the performance of the proposed converter could be effectively examined and the validity of the converter could be verified.
Preparation and Mechanical and Optical Properties of SF/Pyrrolidone Blend Film

To improve the properties of silk fibroin film, the silk fibroin/pyrrolidone blend films were prepared by mixing silk fibroin and pyrrolidone solution at different ratios. The structure and mechanical properties of blend films were characterized. X-ray diffraction was used to investigate structure of the SF/PYR films, and the results indicated that the blend films were composed of the β-sheet form. Tensile strength and elongation at break of blend films were measured using an instron tensile tester. The results showed that tensile strength and elongation at break of blend films were high enough for application. Furthermore, the films’ flexibility was significantly improved. The optical clarity of blend film was tested by Microplate system. It can be seen from the results that optical clarity is not stable, but in some particular ratios we also can get high light transmittance blend films. At last, biocompatibility of blend films (the rate of the blend film is 30%) was accessed with L929 cell. The results showed that all types of blend films were able to support cell adhesion and proliferation. In addition, the cellular morphology of the cells cultured on blend films was better than that on silk fibroin films. In view of the mechanical properties and optical clarity, combined with their ability to support L929 proliferation suggests that this blend films will offer new options in many different biomedical applications.
Decidualized Human Endometrial Stromal Cells Are Sensors of Hormone Withdrawal in the Menstrual Inflammatory Cascade1

ABSTRACT Menstruation is a complex process dependent on premenstrual release of inflammatory mediators and proteolytic enzymes from endometrial cells. Endometrial leukocytes are traditionally considered to be the major source of the inflammatory factors. However, evidence is emerging to suggest a role for decidualized endometrial stromal cells in the premenstrual inflammatory cascade. We sought to determine if withdrawal of hormone support (estrogen and progesterone) from decidualized endometrial stromal cells, in a model mimicking the precise timing leading to menstruation, activated inflammatory signaling pathways and downstream release of inflammatory mediators. Human endometrial stromal cells decidualized gradually over 12 days of estradiol and progestin treatment as evidenced by an increase in prolactin secretion. Withdrawal of hormone support from decidualized stromal cells resulted in a decrease in cytoplasmic IkappaB and a progressive increase in nuclear accumulation of NF-kappaB, as demonstrated by Western immunoblot and immunocytochemical analyses. Concomitant with nuclear translocation of NF-kappaB, hormone withdrawal led to production of a host of inflammatory mediators by the decidualized stromal cells, including IFN-alpha, IL-6, CCL11, GM-CSF, CCL2, IL1-RA, CXCL10, CXCL8, IL-12, IL-15, VEGF, and CCL5. Elevation of inflammatory mediators was not observed, however, upon hormone withdrawal in cells treated with the NF-kappaB inhibitor BAY 11–7085. Decidualized stromal cells are likely highly sensitive sensors of changing hormone levels. This provides a mechanism by which decidualized stromal cells may recruit inflammatory leukocytes into the premenstrual endometrium and contribute to the intense inflammation underlying this unique physiological process.
An empirical study on the risks of using off-the-shelf techniques for processing mailing list data

Mailing list repositories contain valuable information about the history of a project. Research is starting to mine this information to support developers and maintainers of long-lived software projects. However, such information exists as unstructured data that needs special processing before it can be studied. In this paper, we identify several challenges that arise when using off-the-shelf techniques for processing mailing list data. Our study highlights the importance of proper processing of mailing list data to ensure accurate research results.
Guidelines for modelling cold compaction behaviour of various powders

Abstract Through this study, the authors aim to anticipate powder behaviour by account of their intrinsic characteristics and thus giving guidelines for modelling industrial cold die compaction. Investigations are based on complete experimental testing of various industrial powders. Because of the very distinct material properties (metal or ceramic, presence of binder element or lubricant), as well as the morphology, these powders offer a wide range of compaction behaviours that are analysed in order to establish objective considerations for suitable modelling. A global overview of powder behaviour is then proposed, based on two behaviour subtypes regarding powder hardness. By analysing their main features (a new concept is also detailed) it is then possible to simplify the characterisation and modelling of any powder behaviour.
Effect of interface microstructure on the mechanical properties of Pb-free hybrid microcircuit solder joints

Although Sn-Pb eutectic alloy is widely used as a joining material in the electronics industry, it has well documented environmental and toxicity issues. Sandia National Laboratories is developing alternative solder materials to replace traditional Pb-containing alloys. The alloys are based on the Sn-Ag, Sn-Ag-Bi and Sn-Ag-Bi-Au systems. Prototype hybrid microcircuit (HMC) test vehicles have been developed to evaluate these Pb-free solders, using Au-Pt-Pd thick film metallization. Populated test vehicles with surface mount devices have been designed and fabricated to evaluate the reliability of surface mount solder joints. The test components consist of a variety of dummy chip capacitors and leadless ceramic chip carriers (LCCC`s). Intermetallic compound (IMC) layer reaction products that form at the solder/substrate interface have been characterized and their respective growth kinetics quantified. Thicker IMC layers pose a potential reliability problem with solder joint integrity. Since the IMC layer is brittle, the likelihood of mechanical failure of a joint in service is increased. The effect of microstructure and the response of these different materials to wetting, aging and mechanical testing was also investigated. Solid-state reaction data for intermetallic formation and mechanical properties of the solder joints are reported.
Susceptibility of Stored-Product Psocids to Aerosol Insecticides

Abstract The efficacies of commercial methoprene and esfenvalerate aerosols for control of stored-product psocid pests were evaluated in simulated field studies. The efficacies of methoprene, esfenvalerate EC, the carrier Isopar-M™, and a combination of methoprene and esfenvalerate aerosols for control of Liposcelis decolor (Pearman) (Psocoptera: Liposcelididae) and Liposcelis entomophila (Enderlein) nymphs were assessed, and the effects of direct and indirect exposure of Liposcelis bostrychophila Badonnel, L. decolor, and Liposcelis paeta Pearman adults to esfenvalerate EC aerosol were evaluated. The greatest nymphal mortality attained was 76%, indicating that the four aerosols tested were ineffective against L. decolor and L. entomophila nymphs. In the direct and indirect exposure studies, the greatest adult mortalities attained for the three psocid species were 62 and 32%, respectively. Based on these data, esfenvalerate aerosol is ineffective for control of L. bostrychophila, L. decolor, L. entomophila, and L. paeta psocid species. This study shows that methoprene, esfenvalerate EC, and a combination of methoprene and esfenvalerate aerosols were ineffective against the four psocid species tested when applied at rates that are usually effective against other stored-product insect pests.
Minimum cost guaranteed lifetime design for heterogeneous wireless sensor networks (WSNs)

Node placement strategy is an intrinsic issue when provisioning of a wireless sensor network (WSN). In this paper, we address the placement problem for a class of heterogeneous WSNs, wherein nodes have different energy supplies and functionalities. We formulate a generalized node placement optimization problem aiming at minimizing the network cost with constraints on lifetime and connectivity. We propose a placement scheme with two phases. We model the placement of the first phase relaying nodes (FPRNs) as a minimum set cover problem and a dynamic programming algorithm is developed to solve it. For the placement of the second phase relaying nodes (SPRNs), we derive two fundamental design principles-the far-near strategy and max-min strategy. The implementation of the placement schemes is illustrated by examples. Our proposed mechanism is a first attempt towards facilitating realistic relay node placement in WSNs.
Alcohol Taxes and Beverage Prices

Alcohol involvement in auto crashes, homicides, and teen drinking is an important policy concern, and the price of alcohol may have significant effects on these behaviors. Are alcohol taxes quickly and fully passed on to consumers? Given the difficulties of accurately measuring beverage prices, are beer taxes a good empirical proxy for the price of alcohol? Using pooled cross sectiontime series data on state and Federal alcohol taxes and beverage prices, beer taxes are found to be poor predictors of alcohol prices. Controlling for state and period effects, excise taxes appear to be over-shifted: Retail prices rise by more than the amount of the tax, and the rise occurs within 3 months.
The mitigating role of leader‒member exchange when perceiving psychological contract violation: a diary survey study among volunteers

Several scholars in the field of volunteering emphasized the pivotal role of psychological contract (PC) violation in explaining maladaptive behavioural reactions—such as counterproductive work behaviour (CWB)—of volunteers. Reactions to violation feelings are, however, interrelated and may intensify over time. Extending this dynamic perspective, we introduce momentary leader–member exchange (LMX) as a buffering social resource in the relationship between violation feelings and (1) CWB and (2) the likelihood to perceive a PC breach. Using weekly diary survey data from 247 volunteers (827 observations), we conducted a moderated multilevel zero-inflated Poisson regression analysis. As hypothesized, experiencing feelings of violation during one week related positively to CWB towards the organization (CWB-O), but not to CWB towards individuals (CWB-I) during the next week. Moreover, experiencing violation feelings during one week increased the likelihood to perceive a PC breach during the subsequent week. Finally, experiencing a high-quality LMX relationship effectively mitigated the positive relationship between violation feelings during one week and (1) CWB-O, and (2) the likelihood to perceive a PC breach during the next week. Our study highlights momentary LMX as an effective redressing mechanism in the relationship between violation feelings and undesirable employee outcomes.
Adaptive spectrum-based variable bit truncation of discrete cosine transform (DCT) for energy-efficient wireless multimedia communication

This work presents a new adaptive scheme to reduce the computation energy of the discrete cosine transform (DCT) architecture for image/video coding. The scheme employs the noise masking effect of quantization and the spectral difference of the quantization factors. Spectrum-based variable bit truncation is used to allocate more energy for the computations that affect the low frequency DCT coefficients more. We propose a benchmark driven search mechanism based on energy and distortion weight to find the optimal truncation sets for different quality constraints and quantization tables. They are stored in a look-up table (LUT) for the on-line reconfiguration. Simulation results show that significant energy saving is achieved with negligible quality degradation.
Laparoscopic Repair of a Left Paraduodenal Hernia Presenting With Acute Bowel Obstruction: Report of a Case

An internal hernia is any protrusion of a solid organ or a hollow viscus through a defect within the abdominal cavity. Paraduodenal hernias (PDHs) are rare; however, they are the most common form of internal hernias. We present a case of a left PDH in a 59-year-old healthy woman who presented with acute bowel obstruction. The PDH was diagnosed preoperatively using computed tomography scan. Laparoscopic exploration of the abdomen was then performed for reduction of the hernia. Using this approach, we managed to close the defect with intracorporeal continuous suturing with the aim of avoiding future incarceration. The patient was discharged 60 hours postoperation in a good condition, compared with 3 to 28 days postoperation reported in most of the literature. Our search of the english language literature revealed only 16 reported cases of laparoscopic repair of PDH. We believe that laparoscopic treatment of PDH in experienced hands is recommended in selected cases as it decreases the morbidity and significantly shortens the hospital stay.