• Title/Summary/Keyword: harsh environmental conditions

Search Result 83, Processing Time 0.023 seconds

Unified approach to predict the dynamic performance of transportation system considering wind effects

  • Chen, S.R.;Cai, C.S.
    • Structural Engineering and Mechanics
    • /
    • v.23 no.3
    • /
    • pp.279-292
    • /
    • 2006
  • Natural hazards, including the wind hazard and others, threaten the integrity of the modern society. A transportation system usually consists of roadways, bridges and related vehicles. Harsh environmental conditions, caused by such as wind, exist in the real world frequently and affect the dynamic performance of the transportation system through their interactions. Long-span bridges are usually the backbones of transportation lines. In windy conditions, the information about the dynamic performance of bridges and vehicles considering full interactions of environmental factors is very essential for people to assess the overall operational conditions and safety risks of the transportation lines. Most of existent approaches target specifically at several isolated tasks considering partial interaction effects. In order to improve the understanding of these related-in-nature problems integrally as well as the consistency of different approaches, a unified approach to integrally predict the dynamic performance of long-span bridges and vehicles under wind is introduced. Such an approach can be used as a general platform to predict the dynamic responses of vehicles and bridges under various situations through adopting both commercial and in-house software. Dynamic interaction effects can be fully considered automatically for each situation. An example of a prototype bridge in US is given for the purpose of demonstration.

Comparison of Resistance to ${\gamma}$-Irradiation between Cryptosporidium parvum and Cryptosporidium muris Using In Vivo Infection

  • Yoon, Se-Joung;Yu, Jae-Ran
    • Parasites, Hosts and Diseases
    • /
    • v.49 no.4
    • /
    • pp.423-426
    • /
    • 2011
  • In the genus Cryptosporidium, there are more than 14 species with different sizes and habitats, as well as different hosts. Among these, C. parvum and C. hominis are known to be human pathogens. As C. parvum can survive exposure to harsh environmental conditions, including various disinfectants or high doses of radiation, it is considered to be an important environmental pathogen that may be a threat to human health. However, the resistance of other Cryptosporidium species to various environmental conditions is unknown. In this study, resistance against ${\gamma}$-irradiation was compared between C. parvum and C. muris using in vivo infection in mice. The capability of C. muris to infect mice could be eliminated with 1,000 Gy of ${\gamma}$-irradiation, while C. parvum remained infective in mice after up to 1,000 Gy of ${\gamma}$-irradiation, although the peak number of oocysts per gram of feces decreased to 16% that of non-irradiated oocysts. The difference in radioresistance between these 2 Cryptosporidium species should be investigated by further studies.

Conditions of kimchi to be safe from consuming viable Ascaris suum eggs (학술 2 - 김치에 함유된 돼지회충란의 사멸조건)

  • Shin, Sung-Shik
    • Journal of the korean veterinary medical association
    • /
    • v.48 no.9
    • /
    • pp.540-543
    • /
    • 2012
  • Livestock excretes are frequently used in organic farming to produce vegetables and crops. However, zoonotic parasite eggs can be contaminated into such products and people can be infected with parasites of animal origin. Sporadic zoonotic infections with Ascaris suum have been reported even in developed countries, such as North America, Denmark, and the United Kingdom. Ascaris eggs are resistant to most adverse environmental conditions, and pigs and humans become infected by ingestion of fecally excreted eggs through contaminated food, water, or soil. This article discusses the resistant nature of ascarid eggs against harsh environment, and conditions of kimchi to be safe from consuming viable A. suum eggs.

  • PDF

The Ewe's Reproductive Performance, Growth Rate and Carcass Quality of Lambs Kept in a Barn vs Those Kept under an Overhead Shelter

  • Kuznicka, Ewa;Rant, Witold
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.26 no.2
    • /
    • pp.211-217
    • /
    • 2013
  • A herd of polish lowland local sheep was divided into two equal groups: the first group was kept under an overhead shelter, and the second group was kept in a warm barn. The effect of maintenance on ewe's reproductive performance, survival as well as the growth rate of lambs, and their carcasses quality was investigated. The lack of differences in fertility and prolificacy of ewes as well as in the survival and growth rate between the groups confirmed a good adaptation of $\dot{Z}$ela$\acute{z}$nie$\acute{n}$ska sheep to low temperature. Harsh environmental conditions did not cause a significant decrease of the body weight growth; however, they brought in an (insignificant) reduction of subcutaneous fat thickness and meatiness of the loin part of a lamb's body. The fat content of carcasses obtained from lambs reared under the overhead shelter was significantly lower, with no differences of meat and bones contribution between the groups.

Development of a GTT NO96 Membrane Type 170K $m^3$ LNG Carrier with Ice Class IA (GTT.NO 96 멤브레인형 170K ICE-1A급 천연액화가스 운반선 개발)

  • Oh, Yeong-Tae;Han, Sung-Kon;Yoo, In-Sang;Urm, Hang-Sub
    • Special Issue of the Society of Naval Architects of Korea
    • /
    • 2009.09a
    • /
    • pp.6-17
    • /
    • 2009
  • The present paper addresses development of a GTT NO96 membrane type 170K m3 LNG carrier targeted to operate in moderate ice infested seas including Baltic Sea, Sakhalin port of Sea of Okhotsk, Murmansk port of Barents Sea, etc. Critical design issues are covered in detail to meet the requirements coming from the missioned operation conditions comprising low design ambient temperature, harsh wave conditions, stringent environmental protection policies, etc.

  • PDF

Survival of Double-Microencapsulated Bifidobacterium breve in Milk in Simulated Gastric and Small Intestinal Conditions

  • Jung, Ji-Kang;Kil, Jeung-Ha;Kim, Sang-Kyo;Jeon, Jung-Tae;Park, Kun-Young
    • Preventive Nutrition and Food Science
    • /
    • v.12 no.1
    • /
    • pp.58-63
    • /
    • 2007
  • Bifidobacteria are probiotic organisms that provide both flavor and health benefits when incorporated as live cultures into commercial dairy products. Because bifidobacteria are very sensitive to environmental conditions (acids, temperature, oxygen, bile salts, the presence of other cultures, etc.), their viability in human gastrointestinal tract is limited. The microencapsulation of bifidobacteria is a process to protect them against harsh environmental conditions, thereby increasing their viability while passing through human gastrointestinal tract. To confirm the survival rate of microencapsulated Bifidobacterium breve CBG-C2 in milk, their survival rate was compared with several kinds of free bifidobacteria and lactic acid bacteria in commercial yogurt products under simulated gastric and small intestinal conditions. Double-microencapsulation of the bacteria was employed to increase the survival rate during digestion. The outer layer was covered with starch and gelatin to endure gastric conditions, and the inner layer was composed of a hard oil for the upper small intestinal regions. Almost all microencapsulted bifidobacteria in the milk survived longer than the free bifidobacteria and lactic acid bacteria in the commericial yogurt products under the simulated gastric conditions. Numbers of surviving free bifidobacteria and lactic acid bacteria in the commercial products were significantly reduced, however, the viability of the microencapsulated bificobacteria in the milk remained quite stable under gastric and small intestine conditions over 3$\sim$6 hrs. Thus double-microencapsualtion of bifidobacteria in milk is a promising method for improving the survival of bifidobacteria during the digestive process.

Variation of embryonic diapause induction in bivoltine silkworm Bombyx mori L (Lepidoptera: Bombycidae) under controlled conditions

  • Rudramuni, Kiran;Kumar Neelaboina, Bharath;Shivkumar, Shivkumar;Ahmad, Mir Nisar;Chowdhury, Sukhen Roy
    • International Journal of Industrial Entomology and Biomaterials
    • /
    • v.43 no.2
    • /
    • pp.37-44
    • /
    • 2021
  • Mulberry silkworm is classified into uni, bi and multivoltine based on the frequency of diapause incidence. The variation in the incidence of diapause in bivoltine silkworm provides a unique opportunity to study the process of evolution of adaptive plasticity towards seasonal variations. The diapause expression in bivoltine silkworm is highly variable and is determined by environmental factors experienced by the maternal generation. Diapause in natural populations is functionally associated with the overwintering mechanism that facilitates survival in harsh winter conditions. In contrast, under standard commercial rearing conditions, the domesticated bivoltine silkworm is known to enter diapause in every generation. This paper presents a short review of the literature dealing with the role of temperature, photoperiod, diapause hormone and its receptor in diapause induction. Also, we briefly review the incidence of non-diapause eggs in bivoltine silkworm under controlled conditions.

Study on Environmental Resistance of Railway Transponder Tag for Wayside Installation (철도교통 트랜스폰더 태그의 선로변 설치를 위한 내환경성 연구)

  • Kim, Hye Yun;Park, Sungsoo;Yang, Youngoo;Lee, Seung Won;Youm, Ki Jung;Lee, Jae-Ho
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.64 no.6
    • /
    • pp.948-953
    • /
    • 2015
  • In this paper, we studied the environmental requirements for the railway transponder system. The transponder system is comprised of a reader installed beneath the train, a tag installed on the track, and a portable programmer. Among them, the transponder tag should be designed to withstand harsh environments, such as wide operating temperature range, mechanical shock and vibration, etc. To validate stable and reliable service under railway conditions, we carried out environmental test for transponder tag. We then installed the tags on the Honam high-speed test line.

Integrated Sensing Module for Environmental Information Acquisition on Construction Site (건설현장 환경정보 수집을 위한 통합 센싱모듈 개발)

  • Moon, Seonghyeon;Lee, Gitaek;Hwang, Jaehyun;Chi, Seokho;Won, Daeyoun
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.44 no.1
    • /
    • pp.85-93
    • /
    • 2024
  • The monitoring of environmental information (e.g. noise, dust, vibration, temperature, humidity) is crucial to the safe and sustainable operation of a construction site. However, commercial sensors exhibit certain drawbacks when applied on-site. First, the installation cost is prohibitively high. Second, these sensors have been engineered without considering the rugged and harsh conditions of a construction site, resulting in error-prone sensing. Third, construction sites are compelled to allocate additional resources in terms of manpower, expenses, and physical spaces to accommodate individual sensors. This research developed an integrated sensing module to measure the environmental information in construction site. The sensing module slashes the installation cost to 3.3%, is robust enough to harsh and outdoor sites, and consolidates multiple sensors into a single unit. The sensing module also supports GPS, LTE, and real-time sensing. The evaluation showed remarkable results including 97.5% accuracy and 99.9% precision in noise measurement, an 89.7% accuracy in dust measurement, and a 93.5% reliability in data transmission. This research empowers the collection of substantial volumes and high-quality environmental data from construction sites, providing invaluable support to decision-making process. These encompass objective regulatory compliance checking, simulations of environmental data dispersion, and the development of environmental mitigation strategies.

Structural integrity of a 2.5-MW spar-type floating offshore wind turbine under extreme environmental conditions

  • Hanjong Kim;Jaehoon Lee;Changwan Han;Seonghun Park
    • Wind and Structures
    • /
    • v.37 no.6
    • /
    • pp.461-471
    • /
    • 2023
  • The main objective of this study was to establish design guidelines for three key design variables (spar thickness, spar diameter, and total draft) by examining their impact on the stress distribution and resonant frequency of a 2.5-MW spar-type floating offshore wind turbine substructure under extreme marine conditions, such as during Typhoon Bolaven. The current findings revealed that the substructure experienced maximum stress at wave frequencies of either 0.199 Hz or 0.294 Hz, consistent with previously reported experimental findings. These results indicated that the novel simulation method proposed in this study, which simultaneously combines hydrodynamic diffraction analysis, computational dynamics analysis, and structural analysis, was successfully validated. It also demonstrated that our proposed simulation method precisely quantified the stress distribution of the substructure. The novel findings, which reveal that the maximum stress of the substructure increases with an increase in total draft and a decrease in spar thickness and spar diameter, offer valuable insights for optimizing the design of spar-type floating offshore wind turbine substructures operating in various harsh marine environments.