A critical review of slag and fly-ash based geopolymer concrete

Tülin Akçaoğlu,Beste Çubukçuoğlu,Ashraf Awad 사단법인 한국계산역학회 2019 Computers and Concrete, An International Journal Vol.24 No.5

Today, concrete remains the most important, durable, and reliable material that has been used in the construction sector, making it the most commonly used material after water. However, cement continues to exert many negative effects on the environment, including the production of carbon dioxide (CO2), which pollutes the atmosphere. Cement production is costly, and it also consumes energy and natural non- renewable resources, which are critical for sustainability. These factors represent the motivation for researchers to examine the various alternatives that can reduce the effects on the environment, natural resources, and energy consumption and enhance the mechanical properties of concrete. Geopolymer is one alternative that has been investigated; this can be produced using aluminosilicate materials such as low calcium (class F) FA, Ultra-Fine GGBS, and high calcium FA (class C, which are available worldwide as industrial, agricultural byproducts.). It has a high percentage of silica and alumina, which react with alkaline solution (activators). Aluminosilicate gel, which forms as a result of this reaction, is an effective binding material for the concrete. This paper presents an up-to-date review regarding the important engineering properties of geopolymer formed by FA and slag binders; the findings demonstrate that this type of geopolymer could be an adequate alternative to ordinary Portland cement (OPC). Due to the significant positive mechanical properties of slag-FA geopolymer cements and their positive effects on the environment, it represents a material that could potentially be used in the construction industry.

Asymptotics for self-normalized random products of sums of i.i.d. random variables

Pang, T.X.,Lin, Z.Y.,Hwang, K.S. Academic Press 2007 Journal of mathematical analysis and applications Vol.334 No.2

Let {X,X<SUB>i</SUB>;i>=1} be a sequence of independent and identically distributed positive random variables, which is in the domain of attraction of the normal law, and t<SUB>n</SUB> be a positive, integer random variable. Denote S<SUB>n</SUB>=@?<SUB>i=1</SUB><SUP>n</SUP>X<SUB>i</SUB>, V<SUB>n</SUB><SUP>2</SUP>=@?<SUB>i=1</SUB><SUP>n</SUP>(X<SUB>i</SUB>-X@?)<SUP>2</SUP>, where X@? denotes the sample mean. Then we show that the self-normalized random product of the partial sums, (@?<SUB>k=1</SUB><SUP>t<SUB>n</SUB></SUP>S<SUB>k</SUB>kμ)<SUP>&</SUP>mu;<SUP>V''<SUB>t'n</SUB></SUP>, is still asymptotically lognormal under a suitable condition about t<SUB>n</SUB>.

OVERREACTION AND SHORT-TERM MARKET FACTORS IN THE INTEREST RATE FUTURES MARKETS

J Barry Lin,T Chotigeat People&Global Business Association 2000 Global Business and Finance Review Vol.5 No.2

Evidence of stock price overreaction is well documented in most stock markets, but it is quite limited in interest rate futures markets. This paper empirically investigates whether and to what degree, overreaction in interest rate future markets is influenced by recent information (short-term market factors). Using daily data from the interest rates of Eurodollar futures and U.S. T-bond futures, some degree of overreaction was found to be related to short-term market factors. These results have important implications for practitioners, i.e., the opportunity to gain abnormal returns by adopting a "contrarian" investment strategy. For hedgers, transactions are better conducted in days with normal levels of trading activity, as measured in terms of trading volume, intraday volatility, and market movement. On the contrary, professional traders, arbitrageurs, and speculators would find it more attractive to concentrate on days with abnormal levels of trading activity to exploit the larger degree of inefficiency in prices.

Studies on Morphological Characteristics of Korean Taenia saginata taiwanensis from Korea(Cheju Strain)

Chung, W.C.,Lin, C.Y.,Fan, P.C.,Soh, C.T. INSTITUTE OF TROPICAL MEDICINE YONSEI UNIVERSITY 1993 YONSEI REPORTS ON TROPICAL MEDICINE Vol.24 No.1

The present report is of an extensive investigation on the morphology of the adult and cysticercus stages of Korea Taenia (Cheju strain). The data on the adult worm are based on seven worms (two with scolex and five without) obtained from three infected persons. The worms weighed an average of 19.3gm (12∼30gm) and averaged 432cm (303∼665cm) long with 760 (640∼954) proglottides. The scolices averaged 458㎛ (440∼457㎛)×805㎛ (785∼825㎛), sucker 326㎛ (310∼341㎛)×236㎛ (230×242㎛), and rostellum 109㎛ (108∼110㎛)×110㎛ (108∼110㎛). In the mature proglottid, there were 832 (640∼1,034) testes which covered the whole dorsal side of the proglottid except for behind the vitellaria. The two ovaries averaged 430㎛ (250∼610㎛)×301㎛ (175∼550㎛) on the left and 418㎛ (260∼630㎛)×296㎛ (175∼485㎛) on the right. The vitellariae averaged 589㎛ (410∼840㎛)×138㎛ (75∼185㎛) and the mehlis gland 93㎛ (75∼110㎛) in diameter. The cirrus pouch did not extent to the excretory vessel and the vagina had a sphincter. In the gravid proglottid, there were 18 (13∼24) uterine branches, 2 (0∼5) buds, and 59 (23∼102) twigs present on the left side. Those on the right side averaged 18 (13∼24), 2 (0∼5), and 61 (35∼101), respectively. The length, width and thickness of the inner shell (embryophore) of the fixed eggs were 32㎛ (26∼36㎛), 26㎛ (20∼30㎛), and 1.2㎛ (1∼2㎛), respectively. The oncospheres averaged 20㎛ (13∼24㎛)×16㎛ (12∼19㎛); all had six hooks. The corresponding figures for the unfixed or fresh eggs were 35㎛ (28∼51㎛), 29㎛ (24∼43㎛), 2㎛ (1∼3㎛), 27㎛ (20∼35㎛)×22㎛ (18∼28㎛) and 6 hooks, respectively. There were an average of 58,847 (31,540∼89,300) eggs in a gravid proglottid. The length, width and diameters of the protoscolex, rostellum, and suckers of the cysticerci were 1.6mm(0.4∼3.4㎛), 1.5mm (0.3∼3mm), 501㎛ (150∼1,528㎛), 89㎛ (4∼240㎛), and 192㎛ (90∼380㎛), respectively. There were two rows of rudimentary hooklets on the scolex of the cysticerci. The inner hooklets averaged 16 (1∼76) in number and 11㎛ (2∼28㎛) in length. The outer hooklets were numerous and appeared as small dots. The surface of the cysticerci had a tubercular appearanc. These biological and morphological characteristics of Korean Taenia are similar to other T. saginata-like tapeworms in Asia, and have been designated as a new subspecies T. saginata taiwanensis.

Activation of Akt as a mechanism for tumor immune evasion.

Noh, Kyung Hee,Kang, Tae Heung,Kim, Jin Hee,Pai, Sara I,Lin, Ken Y,Hung, Chien-Fu,Wu, T-C,Kim, Tae Woo Academic Press 2009 Molecular therapy Vol.17 No.3

<P>Immune evasion is an important reason why the immune system cannot control tumor growth. To elucidate the mechanism for tumor immune evasion, we generated an immune-resistant human papillomavirus type 16 (HPV-16) E7-expressing tumor cell line by subjecting a susceptible tumor cell line to multiple rounds of in vivo immune selection with an E7-specific vaccine. Comparison of parental and immune-resistant tumors revealed that Akt is highly activated in the immune-resistant tumors. Retroviral transfer of a constitutively active form of Akt into the parental tumor significantly increased its resistance against E7-specific CD8(+) T-cell mediated apoptosis. The observed resistance against apoptosis was found to be associated with the upregulation of antiapoptotic molecules. We also observed that intratumoral injection of an Akt inhibitor enhanced the therapeutic efficacy of E7-specific vaccine or E7-specific CD8(+) T-cell adoptive transfer against the immune-resistant tumors. Thus, our data indicate that the activation of PI3K/Akt pathway represents a new mechanism of immune escape and has important implications for the development of a novel strategy in cancer immunotherapy against immune-resistant tumor cells.</P>

Flow characteristics around a row of circular and wavy cylinders

K. Lam,T. Cai,Y. F. Lin,Y. Liu 대한기계학회 2007 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.21 No.11

The near-wake and flow interference around a row of five circular cylinders, staggered wavy cylinders and nonstaggered wavy cylinders are investigated experimentally by using PIV and LIF techniques. The effects and characteristics of employing wavy cylinders instead of circular cylinders are discussed. The cylinders were arranged at T/d=1.5 with Re ranging from 125 to 40000. Results showed the staggered wavy cylinders give rise to a more stable flow pattern with less fluctuation and longer wake vortex closure length.

P-value significance level test for high-performance steel fiber concrete (HPSFC)

Abdulhameed U. Abubakar,Tülin Akçaoğlu and Khaled Marar 사단법인 한국계산역학회 2018 Computers and Concrete, An International Journal Vol.21 No.5

Statistical analysis has found useful application in the design of experiments (DOE) especially optimization of concrete ingredients however, to be able to apply the concept properly using computer aided applications there has to be an upper and lower limits of responses fed to the system. In this study, the production of high-performance steel fiber concrete (HPSFC) at five different fiber addition levels by volume with two aspect ratios of 60 and 83 were studied under two curing methods completely dry cured (DC) and moist cured (MC) conditions. In other words, this study was carried out for those limits based on material properties available in North Cyprus. Specimens utilized were cubes 100 mm size casted and cured for 28 days and tested for compressive strength. Minitab 18 statistical software was utilized for the analysis of results at a 5 per cent level of significance. Experimentally, it was observed that, there was fluctuation in compressive strength results for the two aspect ratios and curing regimes. On the other hand P-value hypothesis evaluation of the response showed that at the stated level of significance, there was a statistically significant difference between dry and moist curing conditions. Upper and lower limit values were proposed for the response to be utilized in DOE for future studies based on these material properties. It was also suggested that for a narrow confidence interval and accuracy of the system, future study should increase the sample size.

Systemic Inflammation in the Setting of Cardiac Myxomas: an Overview of Clinical and Practical Considerations

Kenan Yalta,Cihan Ozturk,Tülin Yalta,Ertan Yetkin 대한심장학회 2021 Korean Circulation Journal Vol.51 No.9

Is Obesity a Potential Risk factor for Poor Prognosis of COVID-19?

Meltem Agca,Eylem Tuncay,Elif Yıldırım,Reyhan Yıldız,Tülin Sevim,Dilek Ernam,Nermin Ozer Yılmaz,Nazlı Huma Teke,Simge Yavuz,Zuhal Karakurt,COVID-19 Team,Ipek Ozmen 대한감염학회 2021 Infection and Chemotherapy Vol.53 No.2

Background: Coronavirus disease 2019 (COVID-19) continues to cause major mortality and morbidity worldwide even after a year of its emergence. In its early days, hypertension, diabetes, and cardiovascular diseases were noted as poor prognostic factors, while obesity gained attention at a later stage. In the present study, unfavorable clinical outcomes (transfer to the intensive care unit, invasive mechanical ventilation, and mortality) were investigated in obese patients with COVID-19. Materials and Methods: In this retrospective study we analyzed patients with positive polymerase chain reaction test in tertiary care hospital between March-May 2020. They were divided into 3 groups according to body mass index (BMI) as normal, overweight, and obese (BMI: 18.5 - 24.99 kg/m2 , 25 - 29.99 kg/m2 , and ≥ 30 kg/m2 , respectively). We compared clinical features and laboratory findings of these groups and recorded adverse clinical outcomes. Multivariate logistic analysis was performed for unfavorable outcomes. Results: There were 99 patients (35%), 116 (41%), and 69 patients (24%) in the normal-weight, overweight, and obese group, respectively. Among all patients, 52 (18%) patients were transferred to the intensive care unit (ICU), 30 (11%) patients received invasive mechanical ventilation (IMV), and 22 patients (8%) died. Obese patients had minimum 1 more comorbidity than normal BMI patients (73% vs. 50%, P = 0.002), and a longer median (interquartile range [IQR]) duration of hospitalization (8 [5 - 12] vs. 6 [5 - 9]) days, P = 0.006). Obese participants had higher concentrations of serum C-reactive protein, procalcitonin, ferritin than nonobese patients (P <0.05 in all). In a multivariate analysis, obesity was associated with ICU admission (adjusted odds ratio [aOR]: 2.99, 95% confidence interval [CI]: 1.26 - 7.04, P = 0.012). Moreover, IMV requirement was associated with obesity (aOR: 8.73, 95% CI: 2.44 - 31.20, P = 0.001). Mortality occurred in 16%, 9%, and 1% of the obese group, overweight group, and normal-weight group, respectively (Chi-square trend analysis, P = 0.002). Conclusion: Obesity is a risk factor for adverse outcomes and caused increased mortality, hence requiring close follow-up.

Ductal Carcinoma In Situ Detected by Shear Wave Elastography within a Fibroadenoma

Fahrettin Kılıç,Fethi Emre Ustabaşıoğlu,Cesur Samancı,Ahmet Baş,Mehmet Velidedeoglu,Tülin Kılıçaslan,Fatih Aydogan,Mehmet Halit Yılmaz 한국유방암학회 2014 Journal of breast cancer Vol.17 No.2

Fibroadenoma is the most common breast tumor in women. Malignant transformation occurs rarely within fibroadenoma atolder ages. Clinicians, radiologists, and pathologists need to beaware of malignant transformation within fibroadenomas. Radiologicstudies play an important role in the diagnosis of fibroadenoma;however, radiologic findings are often nonspecific formalignancy and may appear completely benign. We detected anoccult ductal carcinoma in situ that originated inside a fibroadenomaby using shear wave elastography. We report shearwave elastography findings of ductal carcinoma in situ withinfibroadenoma and discuss the diagnostic role of this modality.