11 research outputs found

    Development of Eco-VE Function for Construction

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    AbstractRecently accepted ā€œParis Agreementā€ has restricted the Earth temperature increase to be below 1.5 degrees Celsius contrast to previous industrialization. To follow this agreement, there should be efforts such as carbon emission reduction and eco design etc. One of these efforts is development of eco-VE function that applied eco-friendly concept on VE which is commonly used at design phase. Concept of this model includes carbon productivity concept and potential environment pollution index that reflects eco-VE function on original VE. The carbon productivity concept is a cause of production increase that offset production decrease factor depending on green-house gas reduction. The potential environment pollution index presents the possibility of environment pollution through construction phase. The carbon productivity is ā€˜Construction cost/Carbon emissionā€™. The construction costs are consisted of material, equipment, labour cost and indirect expenses. Carbon emissions are calculated by emission for material production and equipment fuel consumption. The potential environment pollution index is composed of environmental pollution and conservation cost. The environmental pollution cost includes environmental damage and destruction cost. The environmental conservation cost includes environmental pollution prevention cost, waste treatment cost, environmental pollution compensation, environmental pollution test research funds and law cost

    Performance Analysis of IEEE802.16e Random Access Protocol with Mobility

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    Abstract. In this paper, the performance of IEEE802.16e random access protocol with handover procedure is examined in terms of access throughput and mean access delay, by using equilibrium point analysis(EPA). In the analysis, retransmission probability, which is a typical input parameter in the literature so far, is iteratively obtained from equilibrium number of backlogs in the system in conjunction with a binary exponential backoff algorithm. In numerical examples, the effects of SSs' mobility on access throughput and mean access delay are examined

    Chemically fluorinated graphene oxide for room temperature ammonia detection at ppb levels

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    Chemoresistive gas sensors based on two-dimensional (2D) materials including graphene-based materials have attracted significant research interest owing to their potential use in next-generation technologies including the Internet of Things (IoT). The functionalization of 2D materials is considered as a key strategy to achieve superior gas sensing properties such as high selectivity, high sensitivity, and reversible response and recovery, because it can modulate the chemical and electrical properties of 2D materials for more efficient gas sensing. Herein, we present a facile solution process and the room temperature gas sensing properties of chemically fluorinated graphene oxide (CFGO). The CFGO sensors exhibit improved sensitivity, selectivity, and reversibility upon exposure to NH3 with a significantly low theoretical detection limit of similar to 6 ppb at room temperature in comparison to NO2 sensing properties. The effect of fluorine doping on the sensing mechanism is examined by first-principles calculations based on density functional theory. The calculations reveal that the fluorine dopant changes the charge distribution on the oxygen containing functional groups in graphene oxide, resulting in the preferred selective adsorption and desorption of NH3 molecules. We believe that the remarkable NH3 sensing properties of CFGO and investigation by first-principles calculations would enlarge the possibility of functionalized 2D materials for practical gas sensing applications such as the IoT.118sciescopu

    Chemically fluorinated graphene oxide for room temperature ammonia detection at ppb levels

    No full text
    Chemoresistive gas sensors based on two-dimensional (2D) materials including graphene-based materials have attracted significant research interest owing to their potential use in next-generation technologies including the Internet of Things (IoT). The functionalization of 2D materials is considered as a key strategy to achieve superior gas sensing properties such as high selectivity, high sensitivity, and reversible response and recovery, because it can modulate the chemical and electrical properties of 2D materials for more efficient gas sensing. Herein, we present a facile solution process and the room temperature gas sensing properties of chemically fluorinated graphene oxide (CFGO). The CFGO sensors exhibit improved sensitivity, selectivity, and reversibility upon exposure to NH3 with a significantly low theoretical detection limit of similar to 6 ppb at room temperature in comparison to NO2 sensing properties. The effect of fluorine doping on the sensing mechanism is examined by first-principles calculations based on density functional theory. The calculations reveal that the fluorine dopant changes the charge distribution on the oxygen containing functional groups in graphene oxide, resulting in the preferred selective adsorption and desorption of NH3 molecules. We believe that the remarkable NH3 sensing properties of CFGO and investigation by first-principles calculations would enlarge the possibility of functionalized 2D materials for practical gas sensing applications such as the IoT

    Results of Active Middle Ear Implantation in Patients With Mixed Hearing Loss After Middle Ear Surgery : A Prospective Multicenter Study (the ROMEO Study)

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    Objectives. This study was conducted to evaluate the user satisfaction, efficacy, and safety of round window (RW) vibro-plasty using the Vibrant Soundbridge (VSB) in patients with persistent mixed hearing loss after mastoidectomy. Methods. The study included 27 patients (mean age, 58.7 years; age range, 28-76 years; 11 men and 16 women) with mixed hearing loss after mastoidectomy from 15 tertiary referral centers in Korea. The VSB was implanted at the RW. The Korean translation of the Abbreviated Profile of Hearing Aid Benefit (APHAB) questionnaire and the Korean version of the International Outcome Inventory for Hearing Aids (K-IOI-HA) questionnaire were used to evaluate user satisfac-tion as the primary outcome. The secondary outcome measures were audiological test results and complication rates. Results. The mean scores for ease of communication (61.3% to 29.7% to 30.2%), reverberation (62.1% to 43.1% to 37.4%), and background noise (63.3% to 37.7% to 34.3%) subscales of the APHAB questionnaire significantly decreased after VSB surgery. The mean K-IOI-HA scores at 3 and 6 months after surgery were significantly higher than the mean preoperative score (18.6 to 27.2 to 28.1). The postoperative VSB-aided thresholds were significantly lower than the preoperative unaided and hearing aid (HA)-aided thresholds. There was no significant difference between preopera-tive unaided, preoperative HA-aided, and postoperative VSB-aided maximum phonetically balanced word-recogni-tion scores. None of the 27 patients experienced a change in postoperative bone conduction pure tone average. One patient developed temporary facial palsy and two developed surgical wound infections. Conclusion. RW vibroplasty resulted in improved satisfaction and audiological test results in patients with mixed hearing loss after mastoidectomy, and the complication rate was tolerable.N

    Caffeic Acid Phenethyl Ester, a Major Component of Propolis, Suppresses High Fat Diet-Induced Obesity through Inhibiting Adipogenesis at the Mitotic Clonal Expansion Stage

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    In the present study, we aimed to investigate the antiobesity effect of CAPE in vivo, and the mechanism by which CAPE regulates body weight in vitro. To confirm the antiobesity effect of CAPE in vivo, mice were fed with a high fat diet (HFD) with different concentrations of CAPE for 5 weeks. CAPE significantly reduced body weight gain and epididymal fat mass in obese mice fed a HFD. In accordance with in vivo results, Oil red O staining results showed that CAPE significantly suppressed MDI-induced adipogenesis of 3T3-L1 preadipocytes. FACS analysis results showed that CAPE delayed MDI-stimulated cell cycle progression, thereby contributing to inhibit mitotic clonal expansion (MCE), which is a prerequisite step for adipogenesis. Also, CAPE regulated the expression of cyclin D1 and the phosphorylation of ERK and Akt, which are upstream of cyclin D1. These results suggest that CAPE exerts an antiobesity effect in vivo, presumably through inhibiting adipogenesis at an early stage of adipogenesis
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