Design of variable screw pitch rib snapping roller and residue cutter for corn harvesters

The blocking between two snapping rollers will seriously constrict the harvesting efficiency for corn harvester. A variable screw pitch rib snapping roller was developed to solve this problem. The comparative experiment between fixed screw pitch rib snapping rollers and variable screw pitch rib snapping rollers illustrated that variable screw pitch ribs can avoid corn-stalk blocking effectively, and it can improve working efficiency by 56.7%. Conservation tillage with standing corn residue was testified that it had a strong control of soil wind erosion. In order to implement this mode of conservation tillage at a production scale, a cutter was developed in this study. Subsequently, two experiments were conducted, one was to test the cutting ratio (defined as the totally cut off stalk population divided by total stalk population), and the other one was to test standing-residue height

A model for analyzing the effect of moving target defenses on enterprise networks

This paper presents an analytical model for determining the effectiveness of moving target defense (MTD) systems in an enterprise network environment. The goal of our model is not to predict the exact probabilities involved with a MTD system, but to provide insight to designers that allows them to make better design decisions when designing their enter-prise networks. We validate the model using a simulation-based of attackers and the MTD system

Towards a Theory of Moving Target Defense

The static nature of cyber systems gives attackers the ad-vantage of time. Fortunately, a new approach, called the Moving Target Defense (MTD) has emerged as a potential solution to this problem. While promising, there is cur-rently little research to show that MTD systems can work effectively in real systems. In fact, there is no standard defi-nition of what an MTD is, what is meant by attack surface, or metrics to define the effectiveness of such systems. In this paper, we propose an initial theory that will begin to answer some of those questions. The paper defines the key concepts required to formally talk about MTD systems and their ba-sic properties. It also discusses three essential problems of MTD systems, which include the MTD Problem (or how to select the next system configuration), the Adaptation Selec-tion Problem, and the Timing Problem. We then formalize the MTD Entropy Hypothesis, which states that the greater the entropy of the system’s configuration, the more effective the MTD system

Effect of Vertical Annealing on the Nitrogen Dioxide Response of Organic Thin Film Transistors

Nitrogen dioxide (NO2) sensors based on organic thin-film transistors (OTFTs) were fabricated by conventional annealing (horizontal) and vertical annealing processes of organic semiconductor (OSC) films. The NO2 responsivity of OTFTs to 15 ppm of NO2 is 1408% under conditions of vertical annealing and only 72% when conventional annealing is applied. Moreover, gas sensors obtained by vertical annealing achieve a high sensing performance of 589% already at 1 ppm of NO2, while showing a preferential response to NO2 compared with SO2, NH3, CO, and H2S. To analyze the mechanism of performance improvement of OTFT gas sensors, the morphologies of 6,13-bis(triisopropylsilylethynyl)-pentacene (TIPS-pentacene) films were characterized by atomic force microscopy (AFM) in tapping mode. The results show that, in well-aligned TIPS-pentacene films, a large number of effective grain boundaries inside the conducting channel contribute to the enhancement of NO2 gas sensing performance

ERK1/2 pathway-mediated differentiation of IGF-1-transfected spinal cord-derived neural stem cells into oligodendrocytes.

Spinal cord injury (SCI) is a devastating event that causes substantial morbidity and mortality, for which no fully restorative treatments are available. Stem cells transplantation offers some promise in the restoration of neurological function but with limitations. Insulin-like growth factor 1 (IGF-1) is a well-appreciated neuroprotective factor that is involved with various aspects of neural cells. Herein, the IGF-1 gene was introduced into spinal cord-derived neural stem cells (NSCs) and expressed steadily. The IGF-1-transfected NSCs exhibited higher viability and were promoted to differentiate into oligodendrocytes. Moreover, the most possible underlying mechanism, through which IGF-1 exerted its neuroprotective effects, was investigated. The result revealed that the differentiation was mediated by the IGF-1 activated extracellular signal-regulated kinases 1 and 2 (ERK1/2) and its downstream pathway. These findings provide the evidence for revealing the therapeutic merits of IGF-1-modified NSCs for SCI

Tailoring the Dielectric Layer Structure for Enhanced Performance of Organic Field-Effect Transistors: The Use of a Sandwiched Polar Dielectric Layer

To investigate the origins of hydroxyl groups in a polymeric dielectric and its applications in organic field-effect transistors (OFETs), a polar polymer layer was inserted between two polymethyl methacrylate (PMMA) dielectric layers, and its effect on the performance as an organic field-effect transistor (OFET) was studied. The OFETs with a sandwiched dielectric layer of poly(vinyl alcohol) (PVA) or poly(4-vinylphenol) (PVP) containing hydroxyl groups had shown enhanced characteristics compared to those with only PMMA layers. The field-effect mobility had been raised more than 10 times in n-type devices (three times in the p-type one), and the threshold voltage had been lowered almost eight times in p-type devices (two times in the n-type). The on-off ratio of two kinds of devices had been enhanced by almost two orders of magnitude. This was attributed to the orientation of hydroxyl groups from disordered to perpendicular to the substrate under gate-applied voltage bias, and additional charges would be induced by this polarization at the interface between the semiconductor and dielectrics, contributing to the accumulation of charge transfer

Antifungal Effects of Saponin Extract from Rhizomes of Dioscorea panthaica Prain et Burk against Candida albicans

Candida albicans is the most common fungal pathogen causing serious diseases, while there are only a paucity of antifungal drugs. Therefore, the present study was performed to investigate the antifungal effects of saponin extract from rhizomes of Dioscorea panthaica Prain et Burk (Huangshanyao Saponin extract, HSE) against C. albicans. HSE inhibits the planktonic growth and biofilm formation and development of C. albicans. 16–64 μg/mL of HSE could inhibit adhesion to polystyrene surfaces, transition from yeast to filamentous growth, and production of secreted phospholipase and could also induce endogenous reactive oxygen species (ROS) production and disrupt cell membrane in planktonic cells. Inhibitory activities against extracellular exopolysaccharide (EPS) production and ROS production in preformed biofilms could be inhibited by 64–256 μg/mL of HSE. Cytotoxicity against human Chang’s liver cells is low, with a half maximal inhibitory concentration (IC50) of about 256 μg/mL. In sum, our study suggested that HSE might be used as a potential antifungal therapeutic against C. albicans

<p>Evaluation on the enhanced solid biofuel from co-hydrothermal carbonization of pharmaceutical biowastes with lignite</p>

Pharmaceutical biowastes are typical wet low-grade industrial biowastes, exhibiting a dual characteristic of hazardous waste and renewable resource. Their efficient and clean energy utilization is important and indispensable from the viewpoint of environmental protection and resource savings. However, low energy density and high nitrogen content are two typical defective characteristics to be resolved. In this study, targeting at solid biofuel product, co-hydrothermal carbonization of two pharmaceutical biowastes (Chinese herb residue and antibiotic fermentation residue) with a low-rank coal (ShenMu lignite coal, SLC) were performed at a fixed prevailing temperature (240 ?) and different mixing mass ratios. The compositional features, the structural properties, and the thermo-chemical behaviors of co-hydrochar products were evaluated to determine their fuel properties. The results indicated that co-hydrothermal carbonization of pharmaceutical biowastes with 25-50% SLC could achieve favorable energy recoveries and nitrogen removal for the reaction system. Under the circumstances, notable synergistic enhancements on both upgradation and denitrogenation capabilities were revealed, producing compatible co-hydrochar with high energy density (HHV up to 24-25 MJ/kg) and stable nitrogen structures (nitrogen content as low as 1.4-2.0 wt%). Furthermore, compared to feedstock or monohydrochar, co-hydrochar product exhibited better pyrolysis behavior with less N-containing and incombustible gaseous components, and longer combustion process with more stable flame. Thus, co-hydrothermal carbonization with lignite coal would be a potential strategy to transform pharmaceutical biowastes into clean and high-grade solid biofuel

Simulation-based Approaches to Studying Effectiveness of Moving-Target Network Defense

Moving-target defense has been hypothesized as a potential game changer in cyber defense, including that for computer networks. However there has been little work to study how much proactively changing a network’s configuration can increase the difficulty for attackers and thus improve the resilience of the system under attack. In this paper we present a basic design schema of a movingtarget network defense system. Based on this design schema, we conducted a simulation-based study to investigate the degree to which proactively changing a network’s various parameters can decrease an adversary’s chance for success. We believe this is an important first step towards understanding why and how the concept of a moving target can be successfully applied to computer network defenses.