139 research outputs found

    Effects of tool coating and tool wear on the surface quality and flexural strength of slotted CFRP

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    Machining of carbon fibre reinforced polymer (CFRP) is abrasive and causes significant tool wear. The effect of tool wear on static flexural strength is investigated, using edge trimming with uncoated carbide and chemical vapour deposition (CVD) diamond coated burr style tools. Edge rounding (ER) criteria along with flank wear are used to observe tool degradation with ER shown to preferentially wear allowing the tool to become cyclically sharper and duller, corresponding to fluctuating dynamometer readings, a novelty for CFRP machining. Areal surface metrics degraded for an uncoated tool due to changes in cutting mechanism, whilst for up to 16.2 m of linear traverse, the coated tool showed limited changes. Tool wear, caused by edge trimming 7.2 m of CFRP, using an uncoated carbide tool, provided a flexural strength reduction of up to 10.5 %, directly linking tool wear to reduced mechanical strength

    Macrophage HIF-1α increases liver tumor

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    Aims/Introduction: Chronic inflammation of the liver is often observed with obesity or type 2 diabetes. In these pathological conditions, the immunological cells, such as macrophages, play important roles in the development or growth of liver cancer. Recently, it was reported that hypoxia‐inducible factor‐1α (HIF‐1α) is a key molecule for the acquisition of inflammatory M1 polarity of macrophages. In the present study, we examined the effects of altered macrophage polarity on obesity‐ and diabetes‐associated liver cancer using macrophage‐specific HIF‐1α knockout (KO) mice. Materials and Methods: To induce liver cancer in the mice, diethylnitrosamine, a chemical carcinogen, was used. Both KO mice and wild‐type littermates were fed either a high‐fat diet (HFD) or normal chow. They were mainly analyzed 6 months after HFD feeding. Results: Development of liver cancer after HFD feeding was 45% less in KO mice than in wild‐type littermates mice. Phosphorylation of extracellular signal‐regulated kinase 2 was also lower in the liver of KO mice. Those effects of HIF‐1α deletion in macrophages were not observed in normal chow‐fed mice. Furthermore, the size of liver tumors did not differ between KO and wild‐type littermates mice, even those on a HFD. These results suggest that the activation of macrophage HIF‐1α by HFD is involved not in the growth, but in the development of liver cancer with the enhanced oncogenic extracellular signal‐regulated kinase 2 signaling in hepatocytes. Conclusions: The activation of macrophage HIF‐1α might play important roles in the development of liver cancer associated with diet‐induced obesity and diabetes

    An Electrostatic-Barrier-Forming Window that Captures Airborne Pollen Grains to Prevent Pollinosis

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    An electrostatic-barrier-forming window (EBW) was devised to capture airborne pollen, which can cause allergic pollinosis. The EBW consisted of three layers of insulated conductor wires (ICWs) and two voltage generators that supplied negative charges to the two outer ICW layers and a positive charge to the middle ICW layer. The ICWs generated an attractive force that captured pollen of the Japanese cedar, Cryptomeria japonica, from air blown through the EBW. The attractive force was directly proportional to the applied voltage. At ≄3.5 kV, the EBW exerted sufficient force to capture all pollen carried at an air flow of 3 m/s, and pollen-free air passed through the EBW. The findings demonstrated that the electrostatic barrier that formed inside the EBW was very effective at capturing airborne pollen; thus, it could allow a home to remain pollen-free and healthy despite continuous pollen exposure

    Electrostatic Insect Sweeper for Eliminating Whiteflies Colonizing Host Plants: A Complementary Pest Control Device in An Electric Field Screen-Guarded Greenhouse

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    Our greenhouse tomatoes have suffered from attacks by viruliferous whiteflies Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) over the last 10 years. The fundamental countermeasure was the application of an electric field screen to the greenhouse windows to prevent their entry. However, while the protection was effective, it was incomplete, because of the lack of a guard at the greenhouse entrance area; in fact, the pests entered from the entrance door when workers entered and exited. To address this, we developed a portable electrostatic insect sweeper as a supplementary technique to the screen. In this sweeper, eight insulated conductor wires (ICWs) were arranged at constant intervals along a polyvinylchloride (PVC) pipe and covered with a cylindrical stainless net. The ICWs and metal net were linked to a DC voltage generator (operated by 3-V alkaline batteries) inside the grip and oppositely electrified to generate an electric field between them. Whiteflies on the plants were attracted to the sweeper that was gently slid along the leaves. This apparatus was easy to operate on-site in a greenhouse and enabled capture of the whiteflies detected during the routine care of the tomato plants. Using this apparatus, we caught all whiteflies that invaded the non-guarded entrance door and minimized the appearance and spread of the viral disease in tomato plants in the greenhouse

    Use of Electric Discharge for Simultaneous Control of Weeds and Houseflies Emerging from Soil

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    An electrostatic apparatus was developed to control weeds and houseflies emerging from ground soil in a greenhouse simultaneously. Identical iron plates were placed in parallel at a defined interval and fixed in an iron frame. Two sets of fixed iron plates were used, one for weed control and one for fly control. For weed control, all of the iron plates were negatively charged, and negative charges accumulated on the plates were released to weed shoots through arc discharge. Houseflies were introduced into the space between the negatively charged and grounded plates, then subjected to arc discharge from the charged plates. Both plant shoots and adult houseflies are electrically conductive; thus, they were killed by discharge-exposure in the electric field between the charged iron plate and the ground soil, and between the charged and grounded plates, respectively. In practical use, these two devices were assembled as a two-level apparatus for simultaneous control of both targets. Several apparatuses were linked together, which increased the total electricity charge on the plates and produced a stronger discharge force sufficient to kill all targets. Thus, this study provides an electrostatics-based pest-control method for pesticide-independent greenhouse farming

    Developing a Phototactic Electrostatic Insect Trap Targeting Whiteflies, Leafminers, and Thrips in Greenhouses

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    Our aim was to develop an electrostatic apparatus to lure and capture silverleaf whiteflies (Bemisia tabaci), vegetable leafminers (Liriomyza sativae), and western flower thrips (Frankliniella occidentalis) that invade tomato greenhouses. A double-charged dipolar electric field producer (DD-EFP) was constructed by filling water in two identical transparent soft polyvinyl chloride tubes arrayed in parallel with fixed separation, and then, inserting the probes of grounded negative and positive voltage generators into the water of the two tubes to generate negatively and positively charged waters, respectively. These charged waters electrified the outer surfaces of the opposite tubes via dielectric polarization. An electric field formed between the oppositely charged tubes. To lure these phototactic insects, the water was colored yellow using watercolor paste, then introduced into the transparent insulator tubes to construct the yellow-colored DD-EFP. This apparatus lured insects in a manner similar to commercially available yellow sticky traps. The yellow-colored DD-EFP was easily placed as a movable upright screen along the plants, such that invading pests were preferentially attracted to the trap before reaching the plants. Furthermore, pests settling on the plants were attracted to the apparatus, which used a plant-tapping method to drive them off the plants. Our study provided an experimental basis for developing an electrostatic device to attract and capture insects that enter greenhouses

    Clinical characteristics of liver failure from a systemic cause: A report from an advanced critical care center

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    Background/Purpose. In Japan, acute liver failure (ALF) has generally been described using the diagnostic term, “fulminant hepatitis”, because of the fact that most cases of ALF has been thought to occur in association with hepatitis mainly due to a hepatitis virus infection. New diagnostic criteria for ALF, including ALF other than fulminant hepatitis, were established in 2011. We therefore examined the prognostic factors of patients with liver failure from a systemic cause, including warfarin users. Material and methods. Sixty-six patients with ALF that were diagnosed according to the Japanese diagnostic criteria for ALF between 2009 and 2013 were divided into a survivor group and a non-survivor group. The data regarding demography, liver tests, coagulation tests, Sequential Organ Failure Assessment (SOFA) scores, and the use of oral warfarin or aspirin were compared between the two groups. Results. The SOFA score was significantly higher in the non-survivor group (p = 0.025). The proportion of oral warfarin users was significantly higher in the survivor group (p = 0.013) (58.1% vs. 26.1%). A multivariate logistic regression analysis showed the SOFA score (odds ratio: 0.851, 95% confidence interval (CI): 0.728-0.995, p = 0.043) and warfarin use (odds ratio: 3.261, 95% CI: 1.028-10.347, p = 0.045) to be significant factors that were negatively and positively associated with the prognosis, respectively. Conclusion. In this study, among the patients with ALF other than fulminant hepatitis, those with a high SOFA score on admission exhibited a poor prognosis. In addition, oral warfarin use prior to disease onset was found to be a factor which indicated a good prognosis

    Analysis of Pole-Ascending–Descending Action by Insects Subjected to High Voltage Electric Fields

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    The present study was conducted to establish an electrostatic-based experimental system to enable new investigations of insect behavior. The instrument consists of an insulated conducting copper ring (ICR) linked to a direct current voltage generator to supply a negative charge to an ICR and a grounded aluminum pole (AP) passed vertically through the center of the horizontal ICR. An electric field was formed between the ICR and the AP. Rice weevil (Sitophilus oryzae) was selected as a model insect due to its habit of climbing erect poles. The electric field produced a force that could be imposed on the insect. In fact, the negative electricity (free electrons) was forced out of the insect to polarize its body positively. Eventually, the insect was attracted to the oppositely charged ICR. The force became weaker on the lower regions of the pole; the insects sensed the weaker force with their antennae, quickly stopped climbing, and retraced their steps. These behaviors led to a pole-ascending–descending action by the insect, which was highly reproducible and precisely corresponded to the changed expansion of the electric field. Other pole-climbing insects including the cigarette beetle (Lasioderma serricorne), which was shown to adopt the same behavior

    Unattended Trapping of Whiteflies Driven out of Tomato Plants onto a Yellow-Colored Double-Charged Dipolar Electric Field Screen

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    An unattended pest control system was developed to eliminate whiteflies (Bemisia tabaci) that settled on greenhouse tomato plants. The system exploited the whitefly’s habit of flying up from a plant that was mechanically tapped and then heading toward yellow objects. Remote-controlled dollies with arms that tapped plants and yellow-colored double-charged dipolar electric field screens (YDD-EFSs) (oppositely electrified transparent insulator tubes filled with yellow-colored water) attracted and trapped the whiteflies. The whiteflies flew up when the plants were mechanically tapped with the dolly’s arms during reciprocating movements and were subsequently trapped by YDD-EFSs that were automatically translocated to the target plants. The system was applied to rows of whitefly-infested tomato plants. Almost all whiteflies transferred to plants were successfully recovered by two dollies moving on either side of the plants, approaching all plants individually (via programmed movement). In summary, we present an efficient unattended method for controlling whiteflies on tomato plants in greenhouses

    Use of a Pair of Pulse-Charged Grounded Metal Nets as an Electrostatic Soil Cover for Eradicating Weed Seedlings

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    An electrostatic technique was developed to generate a simple physical method to eradicate weeds in crop fields. The proposed apparatus consisted of double-expanded metal nets connected to a pulse-charging type negative voltage generator and a grounded line. The two metal nets were arranged in parallel at an interval (6 mm) that caused no arc (spark) discharge between the negatively charged metal net (NC-MN) and the grounded metal net (G-MN). The paired nets were used as a soil cover to zap weed seedlings emerging from the ground. As plant seedlings are biological conductors, the seedling was subjected to an arc discharge from the upper metal net (NC-MN) when it emerged from the soil and passed through the lower net (G-MN). The discharge was strong enough to destroy the seedling with a single exposure. The arc treatment was highly effective for eradicating successively emerging mono- and dicotyledonous weed seedlings, regardless of the number of coexisting weeds or the area of the netted field. Thus, the present study provides a simple and reliable weed eradication method that could be integrated into a sustainable crop production system
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