• 제목/요약/키워드: Niger Delta

검색결과 8건 처리시간 0.018초

Aspergillus niger 고정화 캡슐을 이용한 구연산 생산 특성 (Citric Acid Production Using Encapsulated Aspergillus niger)

  • 정수환;이태종박중곤장호남
    • KSBB Journal
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    • 제10권1호
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    • pp.78-88
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    • 1995
  • 구연산을 생산하고자 캡슐 내부에 A. niger를 고 정화하여 배양하는 경우 곰팡이가 뻗어나와 캡슐 벽 면위에서 성장하게 된다. 배지중의 탄소원이나 산소 가 부족하면 캡슐벽 밖에 나온 균사가 느슨하게 자라게 되며 탄소원과 산소가 충분하면 캡슐벽 밖의 균사는 단단하게 뭉쳐지며 생산성과 생산수율이 매 우 높아진다. 즉 배지의 단위 부피당 적절한 캡슐수 가 존재한다. 배양중에 캡슐막이 팽창하는 현상은 배지중에 $CaCl_2$를 첨가함으로써 방지할 수 있다. 배 지중에 $CaCl_2$를 첨가하는 시기에 따라 생산성은 영향을 받으며, 배양초기에 $CaCl_2$를 첨가하는 경우보 다 배양 7일째에 $CaCl_2$를 첨가하는 경우가 생산수율 이 약 40% 정도 증가하였다. 고정화 캡슐을 이용하 여 플라스크 배양으로 구연산을 생산하는 경우 생산 수율은 산소공급에 큰 영향을 받는다. Parafilm으로 밀봉된 플라스크 대신 산소공급이 원활한 T -flask를 사용하면 생산량은 11배 생산수율(${\Delta}p/{\Delta}s$)은 3.8배 증가하였다. A. niger를 캡슐에 고정화 배양하여 구 연산을 생산하는 경우는 bead에 고정화 배양하여 생산하는 경우보다 6일째부터 13일째 사이에 평균 30 % 이상의 구연산 생산량 증가가 있었다.

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합성탄성파 기록을 이용한 나이지리아의 나이저 삼각주 해안 에포메(Efomeh) 지역의 이상고압 예측 (Overpressure prediction of the Efomeh field using synthetic data, onshore Niger Delta, Nigeria)

  • Omolaiye, Gabriel Efomeh;Ojo, John Sunday;Oladapo, Michael Ilesanmi;Ayolabi, Elijah A.
    • 지구물리와물리탐사
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    • 제14권1호
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    • pp.50-57
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    • 2011
  • 나이지리아의 나이저 삼각주 분지에 위치한 에포메 지역의 이상고압을 효과적이고 정확하게 예측하기 위해 탄성파 및 시추공 자료를 종합적으로 해석하였다. 정상 공극압 영역과 및 이상 공극압 영역을 평균 및 편차의 원리를 기초로 하여 평균속도 경향성으로부터 도시하였다. 두 경향성 사이의 전이는 이상고압영역의 상부경계면을 나타낸다. Dix 근사식에 의해 구해진 구간속도를 이용하여 탄성파자료로부터 이상고압 영역의 상부경계면을 일정한 간격에서 발췌하였다. 예측된 이상고압 영역의 정확도는 에포메(Efomch)01 시추공의 음파검증 자료를 통해 확인되었다. 이상고압 심도의 예측값과 관측값 사이의 편차는 에포메(Efomch)01 시추공에서는 10m 이하 이며, 99퍼센트 이상의 신뢰도를 갖는다. 이렇게 생성된 심도 단면도는 에포메 지역 이상고압 영역의 상부 경계면이 해수면 아래 2655${\pm}$2 m (2550 ms) to 3720${\pm}$2 m (2900 ms)사이에 분포하고 있음을 보여준다. 이 심도는 에포메01 시추공의 지층평가를 이용하면, 두꺼운 해양성 셰일층에 해당한다. 에포메 지역 내의 아그바다층(Agbada Formation)의 하부는 과도한 압력을 받고 있으며, 이상고압의 상부 심도는 조사 지역에 걸쳐 항상 층서경계와 부합되는 것은 아니다. 에포메 지역에 향후 설치할 심도 2440 m 이상 시추공들에서의 이상고압 영역 상부 경계면 예층은 순환손실의 방지와 보다 안전한 시추를 위해 매우 중요한 정보이다.

Mycoflora and Mycotoxins of Cereal Grains in Delta, Egypt

  • Soliman, Hoda M.
    • Mycobiology
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    • 제31권4호
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    • pp.183-190
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    • 2003
  • Five cereal grains(wheat, barley, rice, maize and sorghum) were collected from three Egyptian provinces known to be grain producers(Daqahlia, Gharbia and Kafer el-Sheikh). Two species of Alternaria(A. raphani and A. tenusinae); two species of Aspergillus(A. flavus and A. niger); one species of Cunninghamella(C. elegans); one Dreschslera species(D. myakt); three Fusarium species(F. graminearum, F. moniliform and F. solani); one Rhizopus species(R. stolonifer) and two species of Penicillium(P. digitatum and P. notatum) were isolated from the grains. The densities of these fungi and their frequencies of occurrence have been investigated. All the fungal isolates were tested for the production of toxic metabolites in culture media and the percentages of toxigenic isolates were calculated. The biological assay of the toxigenic fungal isolates showed significant variations in toxigenic activity. Thin layer chromatography revealed that the most active isolate produces moniliformin in culture media. The effect of culture conditions on the production of moniliformin was studied.

A Survey of Open Access Institutional Repositories in Nigerian University Libraries: The Current State

  • Victor Okeoghene Idiedo;Christopher Agbeniaru Omigie;Loveth Ebhomeye
    • International Journal of Knowledge Content Development & Technology
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    • 제14권1호
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    • pp.53-73
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    • 2024
  • The purpose of the study is to investigate the development of institutional repositories in university libraries in Nigeria. The study adopted a survey research design. Online questionnaire, IRs investigation, and interview methods were used to collect data from the 21 university libraries that have developed IRs in Nigeria. The study revealed that only few universities have successfully developed open access IRs to preserve and manage their intellectual outputs emanating from their universities. Contents such as journal articles, theses/dissertations, and conference / workshop papers were found to be the most popular contents that are hosted in the IRs. The interview revealed that although few respondents mentioned having IR policy statements in areas such as access policy, submission policy, preservation policy, content policy and copyright policy, the majority mentioned not having any defined policy in their IR. Also in the interview, inadequate fund, challenge of collecting contents for the IR, shortage of skilled ICT personnel, and inadequate facilities were the most mentioned challenges encountered in the development of IRs in Nigeria. Findings from this study will inform University Librarians, university management and policy makers on the need to provide the necessary infrastructure and formulate policies for smooth development of institutional repositories to make research visible globally. The results will therefore provide important data and insight into the development of institutional repositories in university libraries in the context of developing countries.

배초향 추출액을 이용한 염색포의 염색성 및 항균성 (The Dyeing Properties and Antibiosis of Fabrics Dyed with Agastache rugosa Extract)

  • 박영희
    • 패션비즈니스
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    • 제16권1호
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    • pp.16-25
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    • 2012
  • As the test results for surface color, dyeing durability, antibiosis of cotton fabrics and silk fabrics dyed with Agastache rugosa extract, the following conclusions were obtained. The surface color of all the dyed fabrics was confirmed mostly as a GY system. As the result of chrominance(${\Delta}E_{ab}$) measurement, in the case of cotton fabrics the dyed fabrics treated with $Al_2(SO_4)_3$ mordant showed the highest value and in the case of silk fabrics the non-mordant dyed fabrics showed the highest value. The dyeing durability of test fabrics dyed with Agastache rugosa extract are as follows. As the test results of colorfastness to laundry for cotton dyed fabrics, the discoloration degree showed 1st-2nd grade and the contamination degree showed 4th-5th grade. As the test result of colorfastness to dry cleaning for silk dyed fabrics, the contamination degree showed from 1st to 3rd-4th grade. As the test results of colorfastness to acid artificial perspiration, the discoloration degree showed from 1st to 3rd-4th grade and the contamination degree showed from 3rd to 4th-5th grade. As the test results of colorfastness to alkaline artificial perspiration, the discoloration degree showed from 1st to 4th grade and the contamination degree showed from 3rd to 4th-5th grade. The colorfastness to sunlight showed from 1st to 2nd grade. The colorfastness to rubbing showed from 3rd to 4th-5th grade in dry process and from 2nd-3rd to 4th-5th grade in wet process. As the test results of antibiosis, the decrease rate of germs to virus Klebsiella pneumoniae and Staphylococcus aureus showed at least more than 99% after the wash of 10 times. As the test results of antifungal activity to mycete Trichophyton mentagrophytes and Aspergillus niger, the both cotton and silk dyed fabrics didn't gain the significant antifungal effect.

Butterfly Diversity, Distribution, and Abundance in the University of Port Harcourt River State, Nigeria

  • Efenakpo, Ogaga Dean;Zakka, Usman;Omanoye, Dokubo ThankGod
    • Journal of Forest and Environmental Science
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    • 제37권3호
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    • pp.243-250
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    • 2021
  • Information on butterflies in the Niger Delta Region is relatively scanty because monitoring of their activities and distribution has not been fully documented and these are paramount to establish their conservation protocols. The study therefore aimed at evaluating the species richness distribution pattern, and relative abundance of butterflies in the University of Port Harcourt. The University Park was purposively selected for this study. The park was stratified into three different habitat types (secondary forest, farmland, and residential/garden). A sampling of each stratum was done three times; twice in the morning between 8:00 am and 12:00 pm as well as once in the evening between 4:00 pm and 6:00 pm along a 100 m line transects for 16 months (May 2017-August 2018). Data collected were analyzed for species diversity indices, evenness, and similarity index. A total of 1,932 individual butterflies belonging to 28 species, 18 genera, and five 5 families were identified in the study area. Species diversity and evenness were higher on farmland (1-D=0.909; H'=2.615; E=0.833), and least in the residential area/gardens (1-D=0.744; H'=1.975; E=0.659). The family Nymphalidae (39.0%) had the highest number of species occurrence while Hesperidae (0.4%) had the lowest composition. Anthene larydas (24.12%) had the highest relative abundance in the entire study area, followed by Acraea serena (17.49%). The study, therefore, recommends continuous monitoring of butterfly species diversity and composition also in other regions.

해외진출 한국 기업의 대테러 경호${\cdot}$경비 전략에 관한 연구 (A Study on the Counter-Terrorism and Security Strategy for Korean Companies Engaged in the Overseas Business)

  • 최진태
    • 시큐리티연구
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    • 제13호
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    • pp.507-528
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    • 2007
  • 테러는 지금 이 시간에도 전 세계 곳곳에서 연쇄적으로 발생하고 있어 테러의 시대에 살아가고 있음을 실감나게 하고 있다. 그 동안 테러는 특정 지역에서만 발생하는 국지적인 문제이며, 정치적인 문제만으로 인식하는 경향이 있었다. 최근에 발생하고 있는 테러 사건 중 주목할 만한 것은 해외에서 활동하고 있는 기업과 기업 소속 근로자들이 테러조직의 공격 대상으로 등장하고 있다는 것이다. 기업이 테러의 공격 대상이 된 것은 최근의 일이 아니다. 현대적 의미의 테러의 태동기라고 할 수 있는 1960년대에도 기업과 기업인, 그리고 근로자들에 대한 테러는 있었다. 그러나 세계 여러 나라의 기업들이 테러를 중대한 문제로 인식하지 않고 있었다. 지금은 상황이 변했다. 테러조직들이 국제적인 대도시에 위치한 다국적 기업의 본사는 물론이고 중남미 그리고 아프리카의 건설 현장까지 공격하기 시작했다. 한국의 기업들도 더 이상 예외가 아니다. 2005년 6월 그리고 2006년 1월에 나이지리아에서 발생한 대우건설 근로자 납치사건 그리고 현대중공업 선박에 대한 무장 공격 사건 등은 해외에 진출한 한국 기업 역시 테러로부터 결코 안전하지 않다는 것을 증명했다. 이에 따라 현재 해외에 진출하여 활동하고 있는 기업뿐만 아니라 향후 해외 진출을 고려하는 기업들도 테러에 대한 대책을 마련하지 않으면 안 된다는 것을 교훈으로 남겼다고 할 것이다. 테러 조직이 저지를 수 있는 여러 가지 공격 유형에 대응할 수 있는 전략과 전술을 미리 새워 유사시를 대비하는 노력을 통해 새롭게 등장하고 있는 테러로부터 안전한 기업 경영의 토대를 구축하는 노력을 기울려야 할 것이다.

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Determinants of Smoking Initiation and Susceptibility to Future Smoking among School-Going Adolescents in Lagos State, Nigeria

  • Odukoya, Oluwakemi Ololade;Odeyemi, Kofoworola Abimbola;Oyeyemi, Abisoye Sunday;Upadhyay, Ravi Prakash
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권3호
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    • pp.1747-1753
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    • 2013
  • Background: It is projected that low and middle-income countries will bear a major burden of tobacco related morbidity and mortality, yet, only limited information is available on the determinants of smoking initiation among youth in Africa. This study aimed to assess the determinants of smoking initiation and susceptibility to future smoking among a population of high school school students in Lagos, Nigeria. Materials and Methods: Baseline data from an intervention study designed to assess the effect of an anti-smoking awareness program on the knowledge, attitudes and practices of adolescents was analyzed. The survey was carried out in six randomly selected public and private secondary schools in local government areas in Lagos state, Nigeria. A total of 973 students completed self-administered questionnaires on smoking initiation, health related knowledge and attitudes towards smoking, susceptibility to future smoking and other factors associated with smoking. Results: Of the respondents, 9.7% had initiated smoking tobacco products with the predominant form being cigarettes (7.3%). Males (OR: 2.77, 95%CI: 1.65-4.66) and those with more pro-smoking attitudes (OR: 1.44, 95%CI: 1.34-1.54) were more likely to have initiated smoking. Those with parents and friends who are smokers were 3.47 (95%CI: 1.50-8.05) and 2.26 (95%CI: 1.27-4.01) times more likely to have initiated smoking. Non-smoking students, in privately owned schools (OR: 5.08), with friends who smoke (5.09), with lower knowledge (OR: 0.87) and more pro-smoking attitudes (OR 1.13) were more susceptible to future smoking. In addition, respondents who had been sent to purchase cigarettes by an older adult (OR: 3.68) were also more susceptible to future smoking. Conclusions: Being male and having parents who smoke are predictors of smoking initiation among these students. Consistent with findings in other countries, peers not only influence smoking initiation but also influence smoking susceptibility among youth in this African setting. Prevention programs designed to reduce tobacco use among in-school youth should take these factors into consideration. In line with the recommendations of article 16 of the WHO FCTC, efforts to enforce the ban on the sales of cigarettes to minors should be also emphasised.