• Title/Summary/Keyword: wetA

Search Result 4,552, Processing Time 0.035 seconds

Traffic-induced vibrations at the wet joint during the widening of concrete bridges and non-interruption traffic control strategies

  • Junyong Zhou;Zunian Zhou;Liwen Zhang;Junping Zhang;Xuefei Shi
    • Computers and Concrete
    • /
    • v.32 no.4
    • /
    • pp.411-423
    • /
    • 2023
  • The rapid development of road transport has increased the number of bridges that require widening. A critical issue in the construction of bridge widening is the influence of vibrations of the old bridge on the casting of wet joint concrete between the old and new bridges owing to the running traffic. Typically, the bridge is closed to traffic during the pouring of wet joint concrete, which negatively affects the existing transportation network. In this study, a newly developed microscopic traffic load modeling approach and the vehicle-bridge interaction theory are incorporated to develop a refined numerical framework for the analysis of random traffic-bridge coupled dynamics. This framework was used to investigate traffic-induced vibrations at the wet joint of a widened bridge. Based on an experimental study on the vibration resistance of wet joint concrete, traffic control strategies were proposed to ensure the construction performance of cast-in-site wet joint concrete under random traffic without interruption. The results show that the vibration displacement and frequency of the old bridge, estimated by the proposed framework, were comparable with those obtained from field measurements. Based on the target peak particle velocity and vibration amplitude of the wet joint concrete, it was found that traffic control measures, such as limiting vehicle gross weight and limiting traffic volume by closing an additional traffic lane, could ensure the construction performance of the wet joint concrete.

Effects of the Sintering Variable on Impact Energy in MA 316L ODS and Wet 316L ODS Stainless Steels (MA 316L ODS 및 Wet 316L ODS 스테인리스강에서 충격에너지에 미치는 소결 공정의 영향)

  • Kim, Sung-Soo;Han, Chang-Hee;Jang, Jin-Sung
    • Journal of Powder Materials
    • /
    • v.17 no.2
    • /
    • pp.113-122
    • /
    • 2010
  • Two kinds of oxide-dispersion-strengthened (ODS) 316L stainless steel were manufactured using a wet mixing process(wet) and a mechanical alloying method (MA). An MA 316L ODS was prepared by a mixing of metal powder and a mechanical alloying process. A wet 316L ODS was manufactured by a wet mixing with 316L stainless steel powder. A solution of yttrium nitrate was dried after being in the wet 316L ODS alloy. The results showed that carbon and oxygen were effectively reduced during the degassing process before the hydroisostatic process (HIP) in both alloys. It appeared that the effect of HIP treatment on increase in impact energy was pronounced in the MA 316L ODS alloy. The MA 316L ODS alloy showed a higher yield strength and a smaller elongation, when compared to the wet 316L ODS alloy. This seemed to be attributed to the enhancement of bonding between oxide and matrix particles from HIP and to the presence of a finer oxide of about 20 nm from the MA process in the MA 316L ODS alloy.

Wet-work Exposure: A Main Risk Factor for Occupational Hand Dermatitis

  • Behroozy, Ali;Keegel, Tessa G.
    • Safety and Health at Work
    • /
    • v.5 no.4
    • /
    • pp.175-180
    • /
    • 2014
  • Wet-work can be defined as activities where workers have to immerse their hands in liquids for >2 hours per shift, or wear waterproof (occlusive) gloves for a corresponding amount of time, or wash their hands >20 times per shift. This review considers the recent literature on wet-work exposure, and examines wet-work as a main risk factor for developing irritant contact dermatitis of the hands. The aim of this paper is to provide a detailed description of wet-work exposure among specific occupational groups who extensively deal with water and other liquids in their occupations. Furthermore, it highlights the extent and importance of the subsequent adverse health effects caused by exposure to wet-work.

FERMENTATION QUALITY AND NUTRITIVE VALUE OF BARLEY STRAW AND WET BREWERS' GRAINS SILAGE

  • Ridla, M.;Uchida, S.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.7 no.4
    • /
    • pp.517-522
    • /
    • 1994
  • Three experiments were carried out to evaluate the fermentation process and subsequent nutritional quality of silage made from dried and fresh barley straw with and without the addition of wet brewers' grains. The treatments were: 1 kg of dried straw with 600 g of water but no wet brewers' grains (I - 0) as a control, and the same straw mixed with 2 kg (I - 2), 3 kg (I - 3), 4 kg (I - 4), or 5 kg (I - 5) of wet brewers' grains as treatments in Experiment I; and 2 kg of fresh straw without wet brewers' grains (II - 0) as a control, and the same fresh straw mixed with 2 kg (II - 1), 4 kg (II - 2), 6 kg (II - 3), or 8 kg (II - 4) of wet brewers' grains as treatments in Experiment II. Each material prepared was ensiled in 5 L (vinyl) bag silos, and the silos placed in a chamber of $21^{\circ}C$ for 10 (Exp. I) or 7 (Exp. II) months. The fermentation quality and nutritive value of the barley straw silages produced were markedly improved by mixing them with wet brewers' grains. Increasing levels of wet brewers' grains caused on increase in fermentation quality. The in vitro dry matter digestibility of silages was also increased by adding wet brewers' grains. Two semi scale pilot silages, experiment III, prepared from dried and fresh barley straw mixed with wet brewers' grains were fed to wether sheep. These silages, which contained 50% barley straw and 50% wet brewers' grains by dry weight, were moderate apparent digestibility and supplied of about 50% TDN and DCP.

The Influence of Diamond Abrasive Size on the Life of Tungsten Carbide Wet Drawing Dies (다이아몬드 연마재 입도가 초경 습식신선 다이스 수명에 미치는 영향)

  • Lee, S.K.;Kim, M.A.;Ko, D.C.;Kim, B.M.
    • Transactions of Materials Processing
    • /
    • v.15 no.7 s.88
    • /
    • pp.518-523
    • /
    • 2006
  • Wet wire drawing of brass coated steel wire, used for tire reinforcement, is realized with Tungsten Carbide(WC) dies sintered with a cobalt(Co) binder. Dies wear represents an important limitation to the production process and cost savings. Several parameters, such as Co content, WC grain size of tungsten carbide, sintering conditions, and so on, affect on the wear of the drawing die. In this study, the effect of the diamond abrasive particle size on the life of the WC centered dies of the wet wire drawing was investigated. Wet wire drawing experiments were carried out on a wet wire drawing machine. From the experiments, the dies life, dies fracture, wire surface roughness, and wire breaks were investigated. From the results, it was found that the wear of the WC dies increased with the increase in the diamond abrasive particle size.

Effects of the Type and Percentage of a Lipid on the Quality Characteristics of Rice Bread Depending on the Use of Wet and Dry Rice Flour (습식 및 건식 쌀가루의 유지 종류 및 첨가 비율에 따른 쌀빵 품질 특성)

  • Kim, Sang Sook;Chung, Hae Young
    • The Korean Journal of Food And Nutrition
    • /
    • v.31 no.4
    • /
    • pp.511-519
    • /
    • 2018
  • The baking properties of rice bread with different percentages of butter and oil in wet and dry rice flour were investigated. The moisture, damaged starch, mean diameter, pasting properties by amylogram and RVA (Rapid Visco Analyzer), as well as thermal properties by DSC (Differential Scanning Calorimetry) of wet and dry rice flour were analyzed. The specific gravity and color (L, a, b) of the dough, as well as the appearance, color (L, a, b) and texture of the rice bread with different percentages of butter and oil in wet and dry rice flour were also analyzed. As a result, the wet rice flour were composed of a noted higher content in moisture, compared to the dry rice flour (p<0.001). The wet rice flour had lower values of damaged starch, higher values of mean diameter and a higher peak viscosity than was noted in the dry rice flour (p<0.001). The wet rice flour showed a higher degree of hydration and gelatinization than was seen in the dry rice flour (p<0.001). The prevailing principle to utilize the replacement of wet rice flour with oil had a significant effect on the volume, specific volume and hardness of the rice bread (p<0.001). The hardness of the rice bread also showed a decreasing trend as the amount of the added oil was increased into the mixture. These results suggest that the replacement of wet rice flour with 5.8% oil is effective for the production of rice bread.

Study on the Development of Wet Cell Holder for the Measurement of Hydrophilic Contact Lens (친수성 콘택트렌즈 측정용 Wet Cell 홀더 개발에 관한 연구)

  • Song, Kyoung-Sek;Lim, Hyeon-Sun;Joo, Seok-Hee
    • Journal of Korean Ophthalmic Optics Society
    • /
    • v.20 no.4
    • /
    • pp.455-462
    • /
    • 2015
  • Purpose: To develop more accurate wet measuring system combining the wet cell, automatic lensmeter and the related software for hydrophilic contact lenses and to verify the accuracy of those measuring holder system already available in the market. Methods: Refractive power measurement were done in both a conventional method which has been commonly used in optical shops and a new method which is recently developed in korea. Hydrophilic contact lens of korean brand was chosen as a test material and was tested by water content ratio and by spherical refractive power. Results: When spherical power of -3.00 D contact lens is measured in the newly developed wet cell measurement holder with automatic lensmeter, it reads -3.01 D at water content ratio of 38%. -3.00 D at 45% and -2.98 D at 58%. The same experiment with the Poster soft contact lens wet cell measurement holder maintaining other conditions same resulted in -3.60 D at the water content ratio of 38%, -3.06 D at 45% and -2.46 D at 58%. Conclusions: At the higher water content, the refractive power values measured by both of the wet cell measuring holders are shown lower, and additionally, the new method using the wet cell holder and new software program in a automatic lensmeter showed more accurate readings than conventional Poster soft contact lens wet cell measuring system.

The Effect of Coagulant and Molecular Weight on the Wet Spinnability of Regenerated Silk Fibroin solution

  • Yoo, Young-Jin;Kim, Ung-Jin;Um, In-Chul
    • International Journal of Industrial Entomology and Biomaterials
    • /
    • v.21 no.1
    • /
    • pp.145-150
    • /
    • 2010
  • The regenerated silk fibroin with various molecular weights (MW) was prepared by different dissolution condition and the effect of coagulant on the wet spinnability of the various MW silk fibroin solutions dissolved in formic acid was investigated by the observation of wet spun filament in coagulant and the measurement of maximum draw ratio. The observation on the wet spun filament in coagulation bath revealed that good fibers without bead were formed in a high MW and a very high MW silk fibroin samples. In contrast, beads were observed in the silk fibroin sample with medium MW. The maximum draw ratio of wet spun silk fibroin filament decreased with MW reduction. The decrease of maximum draw ratio in isopropanol, acetone, DMF and THF was remarkably higher than that in methanol and ethanol, indicating that the coagulant type strongly influenced the wet spinnability. The two simple evaluation methods used in this study showed complementary information for wet spinnability: (a) The observation of filament in coagulant was effective to check a continuous fiber formation and a bead formation, and (b) the maximum draw ratio measurement was useful to examine the post drawing ability related to molecular orientation.

Determination of Heavy metals on the non-woven in wet wipes using ICP-MS

  • Choi, Sung-Min;Song, Jin-Kun;Kim, Sang-Jin
    • Journal of the Korean Applied Science and Technology
    • /
    • v.33 no.1
    • /
    • pp.195-203
    • /
    • 2016
  • Heavy metals have been analyzed on the non-woven from the 24 kinds of wet wipes and 8 kinds of mask packs. The following materials used in the non-woven according to each product are: rayon+polyester for the 12 wet wipe products, rayon+PET for the 5 wet wipe products, and rayon, cotton, rayon+polyester+cotton, pulp+polypropylene for the rest of the wet wipe products. No further information on the materials was found on the 3 wet wipes and 8 mask packs. However, polyester may be applied for the non-woven in wet wipes, because PET is part of the polyester group. The heavy metals analysis in the 24 kinds of wet wipes and 8 kinds of mask packs revealed the following: arsenic was found from $47.14{\pm}1.13$ to $71.75{\pm}1.64{\mu}g/L$ on the 3 products, the amount of nickel in the 2 products were $261.26{\pm}5.14$ and $1,242.63{\pm}43.71{\mu}g/L$, $53.69{\pm}1.45$ and $103.52{\pm}2.02mg/L$ on the 2 mask packs. It was also revealed that lead was detected from $7.23{\pm}0.32$ to $55.67{\pm}1.46{\mu}g/L$ on the 6 wet wipes, antimony was ranged from $187.86{\pm}5.24$ to $19,558.35{\pm}3,537.30{\mu}g/L$ on the 12 wet wipes, and $5.25{\pm}0.25$ and $8,936{\pm}55.22{\mu}g/L$ on the 2 mask packs. No cadmium, mercury, or thallium were detected from all the products. A high concentration of antimony might come from antimony trioxide, which was used as a catalyst when manufacturing the polyester. Therefore, it is strongly recommended that a non-woven used for cosmetic purposes should not use heavy metals as a catalyst when manufacturing, and it's important to clarify which materials are used in non-woven.

Development of apparatus for Single-sided Wet Etching and its applications in Corrugated Membrane Fabrication

  • Kim, Junsoo;Moon, Wonkyu
    • Journal of Sensor Science and Technology
    • /
    • v.30 no.1
    • /
    • pp.10-14
    • /
    • 2021
  • Wet etching is more economical than dry etching and provides a uniform etching depth regardless of wafer sizes. Typically, potassium hydroxide (KOH) and tetra-methyl-ammonium hydroxide (TMAH) solutions are widely used for the wet etching of silicon. However, there is a limit to the wet etching process when a material deposited on an unetched surface reacts with an etching solution. To solve this problem, in this study, an apparatus was designed and manufactured to physically block the inflow of etchants on the surface using a rubber O-ring. The proposed apparatus includes a heater and a temperature controller to maintain a constant temperature during etching, and the hydrostatic pressure of the etchant is considered for the thin film structure. A corrugation membrane with a diameter of 800 ㎛, thickness of 600 nm, and corrugation depth of 3 ㎛ with two corrugations was successfully fabricated using the prepared device.