• Title, Summary, Keyword: Mexico

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Simplified Failure Mechanism for the Prediction of Tunnel Crown and Excavation Front Displacements

  • Moghaddam, Rozbeh B.;Kim, Mintae
    • Magazine of korean Tunnelling and Underground Space Association
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    • v.21 no.1
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    • pp.101-112
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    • 2019
  • This case study presented a simplified failure mechanism approach used as a preliminary deformation prediction for the Mexico City's metro system expansion. Because of the Mexico City's difficult subsoils, Line 12 project was considered one of the most challenging projects in Mexico. Mexico City's subsurface conditions can be described as a multilayered stratigraphy changing from soft high plastic clays to dense to very dense cemented sands. The Line 12 trajectory crossed all three main geotechnical Zones in Mexico City. Starting from to west of the City, Line 12 was projected to pass through very dense cemented sands corresponding to the Foothills zone changing to the Transition zone and finalizing in the Lake zone. Due to the change in the subsurface conditions, different constructions methods were implemented including the use of TBM (Tunnel Boring Machine), the NATM (New Austrian Tunneling Method), and cut-and-cover using braced Diaphragm walls for the underground section of the project. Preliminary crown and excavation front deformations were determined using a simplified failure mechanism prior to performing finite element modeling and analysis. Results showed corresponding deformations for the crown and the excavation front to be 3.5cm (1.4in) and 6cm (2.4in), respectively. Considering the complexity of Mexico City's difficult subsoil formation, construction method selection becomes a challenge to overcome. The use of a preliminary results in order to have a notion of possible deformations prior to advanced modeling and analysis could be beneficial and helpful to select possible construction procedures.

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A Study on the Economic Structure of Mexican Northern Borderlands in Relation to the North American Free Trade Agreement (멕시코 북부 국경지대의 경제구조 변화에 관한 고찰)

  • Lee, Jeon;Back, Jong-Gook
    • Journal of the Korean Geographical Society
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    • v.32 no.2
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    • pp.155-174
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    • 1997
  • This paper's main objective is to present an assessment of the impact of NAFTA on the economic structure of the Mexican northem borderlands. The NAFTA is the strategy of a free trade agreement with the United States and Canada, first mentioned by Salinas in June 1990 and established since January 1994. Mexican govemment permitted factories called maquiladoras at the northem borderlands for the first time in 1965. in the early 1980s Mexico was in a deep economic crisis and the international environment was adverse to Mexico. Mexico began to move toward an open economy and abandoned the import-substitution industrialization model that characterized Mexico since the 1930s. Through the new economic reform, the market system was preferred to the regulation; the private ownership, to the public ownership; and the competition, to the protection. The most phenomenal urbanization in northem Mexico has occurred around the major crossing points along the Mexico-U.S. border. The rapid urbanization in northern Mexico has been much due to the industrialization, brought about bv the maquiladora programs and, recently, by the NAFTA.

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Electrochemical Study of Three Stainless Steel Alloys and Titanium Metal in Cola Soft Drinks

  • Peralta-Lopez, D.;Sotelo-Mazon, O.;Henao, J.;Porcayo-Calderon, J.;Valdez, S.;Salinas-Solano, G.;Martinez-Gomez, L.
    • Journal of Electrochemical Science and Technology
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    • v.8 no.4
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    • pp.294-306
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    • 2017
  • Stainless steels and titanium alloys are widely used in the medical industry as replacement materials. These materials may be affected by the conditions and type of environment. In the same manner, soft drinks are widely consumed products. It is of interest for dental industry to know the behavior of medical-grade alloys when these are in contact with soft drinks, since any excessive ion release can suppose a risk for human health. In the present study, the electrochemical behavior of three stainless steel alloys and pure titanium was analyzed using three types of cola soft drinks as electrolyte. The objective of this study was to evaluate the response of these metallic materials in each type of solution (cola standard, light and zero). Different electrochemical techniques were used for the evaluation of the alloys, namely potentiodynamic polarization, linear polarization, and open-circuit potential measurements. The corrosion resistance of the stainless-steel alloys and titanium in the cola soft drinks was provided by the formation of a stable passive film formed by metal oxides. Scanning electron microscopy was used as a complementary technique to reveal corrosion phenomena at the surface of the materials evaluated.

Comparison of Diets of Urban American Indian and Non-Hispanic Whites: Populations with a Disparity for Biliary Tract Cancer Rates

  • Glew, Robert H.;Wold, Rosemary S.;VanderJagt, Dorothy J.
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.7
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    • pp.3077-3082
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    • 2012
  • Aim: The incidence of biliary tract cancer (BTC) is many-fold higher for American Indians (AI) relative to non-Hispanic whites (NHW). Neither gallstones nor genetics can account for this difference. There is speculation that certain fatty acids in bile may play a role in preventing BTC. Since diet may influence composition of bile, we compared the dietary intakes of urban AI and NHW adult women in New Mexico. Methods: Design, a cross-sectional study of the diets of lactating AI and NHW women was conducted. Setting, the University of New Mexico Hospital. Participants, healthy lactating women 18 to 39 years of age were recruited. Main outcome measures, a three-day diet record for each participant was analyzed. Results: The AI women consumed less calcium (p = 0.04) and significantly less short and intermediate chain-length fatty acids (C4-C12), but nearly twice as much proinflammatory arachidonic acid as the NHWs (p <0.01). The intake of dairy products by AI women was less than NHW women (p = 0.01) while the intake of processed meat products was higher (p <0.01). Conclusion: Dietary factors may account for the difference in the risk of BTC between AI and NHW women.

The Role of Private Participation in FTA Negotiation : A Case of U.S., Mexico and Japan (FTA협상에서 민간참여의 역할 : 미국, 멕시코, 일본 사례를 중심으로)

  • Kim, Hong-Youl;Chung, Yong-Kyun
    • International Commerce and Information Review
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    • v.11 no.3
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    • pp.363-390
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    • 2009
  • This study investigates the role of private participation in FTA Negotiation in case of US, Mexico and Japan. We utilize Putnam(1988)'s two stage negotiation model, Schelling Conjecture and Principal-Agent(P-A) theory to understand the role of private sector in FTA Negotiation. Those theories are useful to understand the behavior and interaction of key players such as private sector, congress and government in FTA negotiation. Putnam(1988)'s two stage negotiation model divides the FTA negotiation process into two processes: the external negotiation with foreign country and domestic negotiation with domestic interest group. Principal-Agent(P-A) theory provides the theoretical foundation of Putnam's two stage negotiation model, which is that principal's interest is not identical to the interest of Agent. We showed that the private sector and congress play an important role in FTA negotiation in United States. In case of Mexico, the private sector and government occupy the dominant position in FTA negotiation. In particular, the cooperation of industry and government has been successfully established via COECE in Mexico. In contrast to these countries, the role of private participation in trade policy is relatively low in Japan and Korea.

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Cervical Cancer Trends in Mexico: Incidence, Mortality and Research Output

  • Anaya-Ruiz, Maricruz;Vincent, Ana Karen;Perez-Santos, Martin
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.20
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    • pp.8689-8692
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    • 2014
  • Purpose: To evaluate the recent incidence and mortality of and scientific research trends in cervical cancer in Mexican females. Materials and Methods: Data between 2000 and 2010 from the Department of Epidemiology of the Ministry of Health, and International Agency for Research on Cancer (IARC) of World Health Organization were analyzed, and age-standardized rates (ASRs) were calculated. In addition, scientific research data were retrieved from the Web of Science database from 2003 to 2012, using different terms related to cervical cancer. Results: The incidence rate decreased during last five years, while mortality rates showed an annual decrease of 4.93%. A total of 780 articles were retrieved, and the institutions with the majority of publications were National Autonomous University of Mexico (34.87%), Social Security Mexican Institute (16.02%), and National Institute of Cancerology (15%). The main types of research were treatment, diagnosis, and prevention. Conclusions: The above results show that incidence of cervical cancer decreased over time in Mexico during last five years; similarly, the downturn observed in mortality mainly reflects improved survival as a result of earlier diagnosis and cancer treatment. Also, this article demonstrates the usefulness of bibliometrics to address key evaluation questions and to establish priorities, define future areas of research, and develop cervical cancer control strategies in Mexico.

Mexican Breast Cancer Research Output, 2003-2012

  • Perez-Santos, Jose Luis Martin;Anaya-Ruiz, Maricruz
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.10
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    • pp.5921-5923
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    • 2013
  • The objetive of this study was to explore a bibliometric approach to quantitatively assess current research trends with regard to breast cancer in Mexico. Articles were analyzed by scientific output and research performances of individuals, institutes, and collaborative countries with Mexico. Data were retrieved from the Web of Science database from 2003 to 2012; this was searched using different terms related to breast cancer, including "breast cancer", "mammary ductal carcinoma" and "breast tumour". Data were then extracted from each file, transferred to Excel charts and visualised as diagrams. A total of 256 articles were retrieved. The institutions with the majority of publications were the National Autonomous University of Mexico (22.3%), the National Institute of Cancerology (21.9%), and Social Security Mexican Institute (20.3%); clinical observation studies were the dominant investigation type (64%), and the main types of research were metabolics (24.2%) and pathology (21.5%). This article demonstrates the usefulness of bibliometrics to address key evaluation questions and to establish priorities, define future areas of research, and develop breast cancer control strategies in Mexico.

Prevalence of osteonecrosis of the jaw and oral characteristics of oncologic patients treated with bisphosphonates at the General Hospital of Mexico

  • Cuevas-Gonzalez, Maria Veronica;Diaz-Aguirre, Celia Minerva;Echevarria-y-Perez, Enrique;Cuevas-Gonzalez, Juan Carlos
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.42 no.6
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    • pp.365-369
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    • 2016
  • Objectives: To determine the prevalence and oral characteristics of cancer patients treated with bisphosphonates in the oncology and maxillofacial prosthesis departments of the General Hospital of Mexico between 2011 and 2013. Materials and Methods: This cross-sectional study included patients who received prior treatment with bisphosphonates; an intraoral examination was performed by 2 standardized examiners. Results: The prevalence of bisphosphonate-related necrosis in 75 patients was 2.6%; the most common malignancy was breast cancer (84.0%), followed by prostate cancer (16.0%). Exostosis was present in 9.3% of patients and the mean Decayed, Missing, Filled Teeth index was 4.64; 44.0% of the study group had a Community Periodontal Index value between 2 and 2.9 (mean, 0.60). Conclusion: A detailed intraoral assessment must be performed before initiating treatment with bisphosphonates to identify risk factors for osteonecrosis.