Effects of intermetallic phases on the electrochemical properties of rapidly-solidified Si-Cr alloys for rechargeable Li-ion batteries

Ha, J. A.,Jo, I. J.,Park, W. W.,Sohn, K. Y. 한국물리학회 2016 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol. No.

<P>The microstructures and the electrochemical properties of rapidly-solidified Si-Cr alloys of various compositions were investigated in order to elucidate the effects of intermetallic phases on the cyclic energy capacity of the materials. Rapidly-solidified ribbons of the alloys were prepared by using a melt-spinning process, which is one of the most efficient rapid-solidification processes. The ribbons were fragmented by using a ball-milling process to produce powders of the alloys. To examine the electrochemical characteristics of the alloys, we mixed each of the alloy powders with Ketjenblack(A (R)), a conductive material, and a binder dissolved in deionized water and used it to form electrodes. The electrolyte used was 1.5-M LiPF6 dissolved in ethyl carbonate/dimethyl carbonate/fluoroethylene carbonate. The microstructures and the phases of the alloys were analyzed by using scanning electron microscopy, transmission electron microscopy, and X-ray diffraction analyses. The obtained results showed that the microstructures of the rapidly-solidified Si-Cr alloys were composed of Si and CrSi2 phases. Fine Si particles with diameters of 50 - 100 nm were observed in an eutectic constituent while the sizes of the primary Si and CrSi2 phases were relatively larger at 500 - 900 nm. The specific energy capacities (C) of the Si-Cr alloys decreased linearly with increasing volume fraction (f) of the CrSi2 phase as follows: C = -1,667f + 1,978 after the 50th cycle. The Columbic efficiency after the 3rd cycle increased slightly with increasing volume fraction of the CrSi2 phase; this was effective in improving the cycling capacity of the Si particles.</P>

A Comparison of Short Duration Traffic Counts Methodologies for Estimating Annual Average Daily Traffic

TRANS TECH PUBLICATIONS LTD 2014 Applied Mechanics and Materials Vol.607 No.-

Complex Segregation Analysis of Categorical Traits in Farm Animals: Comparison of Linear and Threshold Models

Kadarmideen, Haja N.,Ilahi, H. Asian Australasian Association of Animal Productio 2005 Animal Bioscience Vol.18 No.8

Main objectives of this study were to investigate accuracy, bias and power of linear and threshold model segregation analysis methods for detection of major genes in categorical traits in farm animals. Maximum Likelihood Linear Model (MLLM), Bayesian Linear Model (BALM) and Bayesian Threshold Model (BATM) were applied to simulated data on normal, categorical and binary scales as well as to disease data in pigs. Simulated data on the underlying normally distributed liability (NDL) were used to create categorical and binary data. MLLM method was applied to data on all scales (Normal, categorical and binary) and BATM method was developed and applied only to binary data. The MLLM analyses underestimated parameters for binary as well as categorical traits compared to normal traits; with the bias being very severe for binary traits. The accuracy of major gene and polygene parameter estimates was also very low for binary data compared with those for categorical data; the later gave results similar to normal data. When disease incidence (on binary scale) is close to 50%, segregation analysis has more accuracy and lesser bias, compared to diseases with rare incidences. NDL data were always better than categorical data. Under the MLLM method, the test statistics for categorical and binary data were consistently unusually very high (while the opposite is expected due to loss of information in categorical data), indicating high false discovery rates of major genes if linear models are applied to categorical traits. With Bayesian segregation analysis, 95% highest probability density regions of major gene variances were checked if they included the value of zero (boundary parameter); by nature of this difference between likelihood and Bayesian approaches, the Bayesian methods are likely to be more reliable for categorical data. The BATM segregation analysis of binary data also showed a significant advantage over MLLM in terms of higher accuracy. Based on the results, threshold models are recommended when the trait distributions are discontinuous. Further, segregation analysis could be used in an initial scan of the data for evidence of major genes before embarking on molecular genome mapping.

Dentists' Perception of the Role they Play in Early Detection of Oral Cancer

Saleh, Amyza,Kong, Yink Heay,Vengu, Nedunchelian,Badrudeen, Haja,Zain, Rosnah Binti,Cheong, Sok Ching Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.1

Background: Dentists are typically the first professionals who are approached to treat ailments within the oral cavity. Therefore they should be well-equipped in detecting suspicious lesions during routine clinical practice. This study determined the levels of knowledge on early signs and risk factors associated with oral cancer and identified which factors influenced dentist participation in prevention and early detection of oral cancer. Materials and Methods: A survey on dentists' knowledge and their practices in prevention and early detection of oral cancer was conducted using a 26-item self-administered questionnaire. Results and Conclusions: A response rate of 41.7% was achieved. The level of knowledge on early signs and risk habits associated with oral cancer was high and the majority reported to have conducted opportunistic screening and advised patients on risk habit cessation. Factors that influenced the dentist in practising prevention and early detection of oral cancer were continuous education on oral cancer, age, nature of practice and recent graduation. Notably, dentists were receptive to further training in the area of oral cancer detection and cessation of risk habits. Taken together, the study demonstrated that the dental clinic is a good avenue to conduct programs on opportunistic screening, and continuous education in these areas is necessary to adequately equip dentists in running these programs. Further, this study also highlighted knowledge deficits and practice shortcomings which will help in planning and developing programs that further encourage better participation of dentists in prevention and early detection of oral cancer.

Effect of Scoria on Various Specific Aspects of Lightweight Concrete

Eddie Franck Rajaonarison,Alexandre Gacoin,Roger Randrianja,Velomanantsoa Gabriely Ranaivo,Bam Haja Nirina Razafindrabe 한국콘크리트학회 2017 International Journal of Concrete Structures and M Vol.11 No.3

Experimental research on the technical characteristics of lightweight concretes incorporating scoria was conducted. The objective of this research is to investigate the feasibility and effectiveness of the use of scoria, in lightweight concretes. Coarse scoria of 5/10 and 10/20 mm were used. A portion of the aggregate mixtures had an average particle size ≤100 ㎛. Scorias are often used as the constituents of structural concrete and insulating materials. The usability of the concretes tested in this study broadens as the porosity of the mixtures decreased and the cement dosage increased. According to the cement dosage and frequency types, the absorption coefficients of concretes ranged from 0.14 to 0.47. A compressive strength of 19 MPa corresponded to a density of 1800 kg/m³; compressive strengths from 10 to 18 MPa mapped to densities ranging from 1300 to 1700 kg/m³. The thermal conductivity of mixed concretes without scoria reached a maximum value of 0.268 W/m K. The thermal conductivity values of the concretes mixed without sand were below 0.403 W/m K. As sand content increased, the conductivity evolved from 0.565 to 0.657 W/m K. Freeze-thaw stability tests were conducted for 400 cycles or until specimens deteriorated. The experimental results helped in determining the optimum mixing conditions for the inclusion of scoria in cement to produce lightweight concretes.

Size-dependent cellular uptake of sodium alginate passivated tin dioxide nanoparticles in triple-negative breast cancer cells

Chandrasekaran Karthikeyan,Kokkarachedu Varaprasad,Sungjun Kim,Ashok Kumar Jangid,Wonjeong Lee,Abdulrahman Syedahamed Haja Hameed,Kyobum Kim 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.123 No.-

The new development of inorganic (IO) nanoparticle (NPs)-based nanomedicines in anticancer therapy isan active area of research. The cellular uptake of IO NPs plays a crucial role in their efficacy as anticanceragents. In this case, IO NPs cellular uptake depends on physical and chemical parameters, including size,shape, and surface modification of the nanoparticles. From the cellular uptake, one of the essentialparameters for small size plays a critical role in the NPs’ due to their ability to passively diffuse acrossthe cell membrane or enter cells through endocytosis. In this study, the inorganic SnO2 (tin dioxide)and SA (sodium alginate) were made into SnO2 (SASnO2) using a simple one-pot green method. Biomedical studies have shown that SASnO2 NPs exhibit greater antibacterial, antioxidant, and anticancerproperties than SnO2 NPs. The prepared SnO2 and SASnO2 NPs were tested against breast cancer cells inanticancer studies. In cellular uptake studies, the smaller size of SASnO2 NPs (19 nm) resulted in highercellular uptake compared to SnO2 NPs (38 nm). The larger surface area of these SASnO2 NPs allows formore contact with biological membranes and internalization (cell uptake) by cancer cells, resulting inenhanced anticancer therapy when using SASnO2 NPs.