Design, synthesis, and evaluation of a highly effective and safe perfluoro-alternative with "weak site" : potassium 1,1,2,2,3,3,4,4-octafluoro-4-(perfluorobutoxy)butane-1-sulfonate

A novel, highly efficient, degradable alternative perfluorinated compound (APFC) with "weak site" was synthesized using various methods via a common intermediate. The main reactions were oxidation by sulfonyl chloride, chlorination,...

Risk Management of Construction in Sudan

This paper aims to study the humanitarian risks in construction projects that affect the objectives of the project from time, cost and quality, and to identify, analyze and develop the appropriate strategy, monitor and control and specifically the risk of factors affecting construction projects. A questionnaire was designed to collect data and identify risks in construction projects and then distributed to several public and private sector companies registered with the Organizing Council for engineering works contractors in Sudan, and after the risks facing the construction projects were identified through the questionnaire and telephone interviews with The engineers and managers of these companies, these risks were analyzed by Google Form. The results of the questionnaire showed that inflation, increased prices of materials in the market, weak site management, delayed payments from the contractor and awarding the design to unqualified designers, that is the most important factors affecting the objectives of construction projects in Sudan, and the contractor is the most vulnerable among the parties to the project.

Mentoring and Career Development of Academics in Colleges of Education in Cross River State Nigeria

Currently the reasons for mentoring in our career is on the increase as the operational environment is embedded with risk , change ,staff competition, unethical career practices , high uncertainty, unfavourable government policy implementation and ignorance of the role of mentors being in control of the weak site. It is grossly required for good mentoring to be in our educational system of rewards and promotion. The study therefore investigates mentoring and career development of academia in colleges of education in Cross River state, Nigeria. A descriptive survey research design was adopted for the study. The population for the study comprised all the 1075 Chief lecturers and young lecturers ’while multi choice sampling technique was used to sample 570 respondents. One research question and two research hypotheses guided the study. The researcher developed questionnaires tagged ‘Mentoring and Career Development for Academia Questionnaire’ (MCDAQ). Questionnaire containing 12 items was the instrument for data collection, which was validated by three experts from the University of Calabar, Calabar with total reliability coefficients of 0.82. Mean ratings and standard deviation were used in answering the research questions. While T test was used in testing the hypothesis. The major findings of the study revealed that mentoring is in practices in collages of education in Cross River state, Nigeria. That there is mentoring relationships among academic staff. The study also revealed that female face more challenges in course mentoring than the male academic

Site occupancy of transition elements in C15 NbCr2 laves phase: A first-principles study

Using first-principles calculations, site occupancy behaviors of transition elements in C15 NbCr2 Laves phase are systematically investigated. Elements Y, Sc, Zr, Hf, Cd, Ta, Ti and Ag prefer to occupy the Nb site, and elements Zn, Pt, Re, Tc, Ir, V, Os, Rh, Ru, Ni, Co, Mn, Fe and Cu favor to occupy the Cr site; whereas elements Mo, W, Pd and Au have weak site preference for Cr or Nb site. The present calculations agree well with the available experimental and previously calculated results. It was found that the site occupancy behavior of transition elements in NbCr2 is mainly affected by the radii of transition elements. The present calculations also propose the correlation between the site preference energy and radii of transition elements.

Reliability Modeling and Assessment of Component with Multiple Weak Sites under Complex Loading

A component with multiple weak sites is widely used in practical engineering and the existence of multiple weak sites can significantly decrease the component reliability. On the other hand, only a few components bear static loading and most components bear dynamic loading. In this paper, a reliability model of isomorphic component with multiple weak sites is built based on an order statistics model and the influences of strength decentrality and loading decentrality on isomorphic component with multiple weak sites are discussed. Furthermore the influence of loading times is studied in detail. The results show that unlike a component with only one weak site, not only does the failure of a component with multiple weak sites have a relationship with the safety margin, but there also exist relationships with the number of weak sites, the loading roughness, and loading times. The work in this paper is of some guiding significance in reliability design and assessment of a component with multiple weak sites under complex loading.

Experiment Study on Fatigue Strength of Used Type Zhuan 8G (Zhuan8AG) Side Frame under the Speed Increased Condition

The using zhuan 8G (zhuan 8AG) bogie in existing line whether can achieve the requirement of speed increased to 120 km/h, and what improvements and research became the railway sector need to face and solve importantly. Based on the experiment standard of new production and strengthened project, fatigue strength performance is studied on type zhuan 8G (zhuan 8AG) side frame used for some years when speed increases to 120 km/h. The static stress examination shows that the static strength of side frame is related to its structural design while has nothing to do with its using life. The fatigue test research indicates that the total state of used side frame is comparatively good, and the foreground used for 120 km/h is optimistic; and find that the corner of pile cap lower part(C position) is the weak site of side frame fatigue failure, the reason is closely related to the surface defect of this site. The recommendation is improving the quality requirements of this part of the side frame manufacturing technology and quality controlling document to eliminate the hidden dangers of fatigue source. Conclusions and suggestions may be referred to when competent departments make relevant decision, and offer contrast for relevant calculation study.

The Interaction of Soluble Phospholipids with Coagulation Factor VIIa

Abstract 4421 Factor VIIa (fVIIa) is one of the key proteins in the blood coagulation cascade. It activates factors IX and × on a negatively charged phospholipid surface in either a TF-dependent or TF-independent fashion (Silverberg et al, 1977; Bom et al, 1990). Monroe et al (1997) demonstrated that fVIIa binds to activated platelets independent of TF and partially restores thrombin generation in an in vitro model of hemophilia. Thus, it appears that interaction of fVIIa with platelet phospholipids plays an important role. We report that binding of 1,2-dihexanoyl-sn-glycero-3-phospholipids -L-serine (C6PS) and 1,2-dihexanoyl-sn-glycero-3-phosphoethanolamine (C6PE) to fVIIa causes changes in its activity as well as structure. Titration with C6PS led to changes in intrinsic fluorescence indicative of two or more binding sites for this lipid. Similar titrations with C6PE indicated that it probably binds to a single site on the protein. Experiments are underway to test this initial conclusion. Both lipids bind with comparable affinity (kd ~ 165 and 160 μ M) when data were analyzed using a single site model. We also examined the effect of the soluble lipids on the activity of fVIIa. Both C6PS and C6PE binding increased fVIIa proteolytic and amidolytic activity, with the effect of C6PS being more pronounced. Based on current data, it appears that both lipids bind to a single weak site, but that binding of either to this site promotes binding of C6PS to a second, tighter, and C6PS-specific site, which seems to be crucial in regulating activity. Further experiments are underway to test this hypothesis. Disclosures: No relevant conflicts of interest to declare.