Miracle-dz/UniFAR-FTUs huggingface dataset:
A simple approach to determine the diffusivity of americium in granite

Abstract The diffusivities of the key radionuclides in host rock are important for the performance assessment of repositories. One of the conventional methods for determining the diffusivities of radionuclides is to grind the rock tablet layer by layer and then to measure the radioactivity remaining on the rock tablet before each grinding cycle. Since grinding hard rock samples, especially those with radioactivity, is very difficult, we developed a new approach to determine the diffusivity of americium in granite. The new approach mainly includes two parts: one is to measure the radioactivities from both sides of a rock disk sample by autoradiography with phosphor imaging technique; the other is to study the relationship between the radioactivities and the apparent diffusivity of americium in granite by computer modelling. Because the high contamination risk of grinding radioactive rock samples has been avoided, the new approach is much simpler than the conventional method. It may be a better choice of measuring the diffusivities of radionuclides in rock, especially for those laboratories in which grinding radioactive rock samples is inconvenient.
Raman spectroscopic evaluation of polyacrylonitrile‐based carbon nanofibers prepared by electrospinning

Poly(acrylonitrile) (PAN) solutions in N,N-dimethylformamide were electrospun into webs consisting of 350 nm ultra-fine fibers. The webs were oxidatively stabilized and followed by heat treatment in the range of 700–1000°C. Characterization of the microstructure of PAN-based carbon nanofibers was performed by x-ray diffraction, field-emission scanning electron microscopy, electrical conductivity and Raman spectroscopy. The Lc(002) and La(10) values were calculated to be 1.85–2.15 and 2.23–3.36 nm, respectively. The Lc(002) and La(10) values increased by about 86% and 66%, respectively, when the heat treatment temperature (HTT) was increased from 700 to 1000°C. The electrical conductivity of carbonized PAN nanofiber webs increased with increasing carbonization temperature, being 6.8 × 10−3 and 1.96 S cm−1 at 700 and 1000°C, respectively. The D and G bands from Raman scattering were fitted into a Gaussian–Lorentzian hybridized function, and the crystallite sizes in the nanofibers were evaluated from the R-values determined from the ratios of the intensity of the G band to that of the D band. The domain size of the graphitic layers was in the range 1.6–3.2 nm with higher values at higher HTT. Copyright © 2004 John Wiley & Sons, Ltd.
Collisional Shift of the Tl Hyperfine Lines in Atmosphere of Inert Gases

New relativistic approach, based on the gauge‐invariant perturbation theory [1,2] with using the optimized wave functions basis’s, is used to calculating inter atomic potentials, hyper fine structure (hfs) collision shift for Tl atom in atmosphere of inert gases. Data for inter atomic potentials, collision shifts of the Tl hfs in atomosphere of gases He,Ar
Typical severe dust storms in northern China during 1954 —2002

Based on China’s available daily observation data from 681 national meteorological stations from 1954 to 2002, a time series of typical severe dust storms in northern China is constructed in terms of the weather process, and the temporal and spatial distribution, and their evolution tendency is analyzed. The results indicate that there were 223 relatively typical severe dust storms in northern China from 1954 to 2002, among which the event on April 10–12, 1979 had the largest affected area. Closely associated with the geographical distribution of deserts, sandy lands and the tracks of strong cold air outbreaks, severe dust storms mainly occurred in the Tarim Basin, the eastern part of Northwest China and the northern part of North China. The season with the most frequent severe dust storms was spring, in which the frequency accounts for 82.5% in the whole year, while the least occurrence was in summer and autumn. During the past 49 years, the highest frequency of severe dust storms occurred in the 1950s and the lowest was in the 1990s with a general descending tendency, but during 2000–2002 the occurrence was relatively increasing. On the average, the duration of severe dust storms was shortest in the 1990s, about 0.5–1 h shorter than that in the other 4 decades.
Rigid poly(vinyl chloride) (PVC) gelation in the brabender measuring mixer. I. Equilibrium state between sliding, breaking, and gelation of PVC

This article discusses the first part of the Brabender typical torque process curves. Rigid poly(vinyl chloride) (PVC; Polanwil S-61) was processed at various temperatures between 160 and 200°C with blade speeds in the range of 5–40 min−1. The morphological changes of the processed compound was characterized by scanning electron microscopy and optical microscopy, and the degree of gelation was estimated on the basis of DSC thermograms. The values of torque minimum strongly depends on temperature. Shear rate affects mainly the time of reaching the minimum torque. The grains are disintegrated into the nonuniform particles and aggregates of the dimensions between 20 and 4 μm. The significant variation of the gelation degree was found for the sample produced in the same conditions and unloaded from Brabender chamber at minimum of torque. It was found that the value of the minimum of torque described momentary equilibrium state between sliding of breaking grains and increasing degree of PVC gelation. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 966–971, 2004
ASSESSING THE IMPORTANCE OF BREAST SELF EXAMINATION AND BREAST CANCER AWARENESS AMONG HEALTH CARE PROFESSIONALS

: INTRODUCTION: Breast cancer appears to be a disease of both developing and developed country. Breast cancer is now the most common cancer in most cities in India, and 2nd most common in the rural areas. OBJECTIVES: 1. To assess the knowledge, attitude and practice of self breast examination among health care professionals. 2. To assess breast cancer awareness among health care professionals. METHODOLOGY: A questionnaire based cross sectional study in which 133 women belonging to various medical and allied specialties were included. RESULTS: It was found that most (91%) respondents were aware of BSE. The electronic media were the major sources of information followed by information from co-health workers. The attitude of health professionals on BSE was positive, with a fairly high degree of acceptability of the idea. Despite the positive attitude to BSE, its practice was low (73.7%). CONCLUSION: BSE is a cost effective screening modality. In view of worldwide rising trends in the incidence of breast cancer rates, importance of BSE should be popularised through mass media.
Study on pretreatment of landfill leachate by potassium ferrate

ABSTRACTLandfill leachate is nonbiodegradable because it contains many kinds of pernicious and toxic components. Potassium ferrate is used as a pretreatment agent in the experiments for it is a kind of oxidant that can be used to oxidize and disintegrate lots of organics. However, with respect to the treatment effect of landfill leachate, several important parameters should be studied. Such parameters included (a) the dosage of potassium ferrate, (b) the pH value, (c) the reaction time, (d) the concentration of landfill leachate, and (e) the dosage of stabilizing agent. Finally, the optimum conditions for the treatment of landfill leachate were confirmed. The conditions included (a) the dosage of potassium ferrate was 6 g/L, (b) pH value was 10, (c) the reaction time was 30 min, and (d) the dosage of stabilizing agent—sodium silicate was 4 g/L. After treated under those conditions, the CODCr removal efficiency was 36% and UV-254 value decreased from 10 to 6.64 cm−1.
Model of plasma immersion ion implantation

In plasma immersion ion implantation, a target is immersed in a plasma and a series of negative high‐voltage pulses are applied to implant plasma ions into the target. We develop an approximate analytical model to determine the time‐varying implantation current, the total dose, and the energy distribution of the implanted ions.
Bimodality of molecular mass distribution of polydienes obtained under the action of dilithium initiators in hydrocarbon media: the reasons, mathematical simulations, and their experimental testing

Bimodal molecular mass distribution (MWD) of polymers, obtained upon polymerization of hydrocarbon monomers in the nonpolar media under the action of dilithium initiators, is the consequence of separation of the reaction mixture into two phases. Bifunctional /living/ oligomers produce the insoluble sediment due to tetrameric association of the lithium active sites (the swollen gel-fraction). Part of the active site remains in the solution (the solfraction). Difference in the concentrations of the active sites into the phases leads to difference between the propagation rates of the /living/ chains and, as a result, to Bimodal MWD. The mathematical model of polymerization in the two-phase system is proposed. Satisfactory agreement between the calculations and the experiments is shown for butadiene polymerization in heptane under the action of 1,4-dilithiumpentane. Regulation of MWD up to the complete elimination of bimodality is possible via the programmed dosage of monomer and solvent into the reactor.
Water Single-Phase Fluid Flow and Heat Transfer in Capillary Tubes

This paper reports the results of an experimental investigation of fluid flow and single-phase heat transfer of water in stainless steel capillary tubes. Three tube diameters are tested: 172 μm, 290 μm and 520 μm, while the Reynolds number varying from 200 up to 6000. Fluid flow experimental results indicate that in laminar flow regime the friction factor is in good agreement with the Hagen-Poiseuille theory for Reynolds number below 800–1000. For higher values of Reynolds number, experimental data depart from the Hagen-Poiseuille law to the side of higher f values. The transition from laminar to turbulent regime occurs for Reynolds number in the range 1800–3000. This transition is found in good agreement with the well known flow transition for rough commercial tubes. Heat transfer experiments show that heat transfer correlations in laminar and turbulent regimes, developed for conventional size tubes, are not adequate for calculation of heat transfer coefficient in microtubes. In laminar flow the experimental values of heat transfer coefficient are generally higher than those calculated with the classical correlation, while in turbulent flow regime experimental data do not deviate significantly from classical heat transfer correlations. Deviation from classical heat transfer correlations increase as the channel diameter decrease.Copyright © 2003 by ASME
Boiling Potassium Chloride–Extractable Nitrogen as an Index of Potentially Mineralizable and Plant‐Available Nitrogen in Soil

Abstract Mineralization of soil organic nitrogen (N) and its contribution toward crop N uptake is central to developing efficient N‐management practices. Because biological incubation methods are time consuming and do not fit into the batch‐analysis techniques of soil‐testing laboratories, an analytical procedure that can provide an estimate of the mineralizable N would be useful as a soil‐test method for predicting plant‐available N in soil. In the present studies, the ability of boiling potassium chloride (KCl) to extract potentially mineralizable and plant‐available N in arable soils of semi‐arid India was tested against results from biological incubations and uptake of N by wheat in a pot experiment. Mineralization of organic N in soils was studied in the laboratory by conducting aerobic incubations for 112 days at 32°C and 33 KPa of moisture. Cumulative N mineralization in different soils ranged from 8.2 to 75.6 mg N kg−1 soil that constituted 2.7 to 8.8% of organic N. The amount of mineral N extracted by KCl increased with increase in length of boiling from 0.5 to 2 h. Boiling for 0.5, 1, 1.5, and 2 h resulted in an increase in mineral‐N extraction by 9.3, 12.7, 19.6, and 26.1%, respectively, as compared to mineral N extracted at room temperature. The boiling‐KCl‐hydrolyzable N (ΔNi) was directly dependent upon soil organic N content, but the presence of clay retarded hydrolysis for boiling lengths of 0.5 and 1 h. However, for boiling lengths of 1.5, and 2 h, the negative effect of clay was not apparent. The ΔN i was significantly (P=0.05) correlated to cumulative N mineralized and N‐mineralization potential (N0). The relationship between N0 and ΔN i was curvilinear and was best described by a power function. Boiling length of 2 h accounted for 78% of the variability in N0. Results of the pot experiment showed that at 21‐ and 63‐day growth stages, dry‐matter yield and N uptake by wheat were significantly correlated to boiling‐KCl‐extractable mineral N. Thus, boiling KCl could be used to predict potentially mineralizable and plant‐available N in these soils, and a boiling time of 2 h was most suitable to avoid the negatively affected estimates of boiling‐KCl‐hydrolyzable N in the presence of clay. The results have implications for selecting length of boiling in soils varying widely in clay content, and this may explain why, in earlier studies, longer boiling times (viz. 2 or 4 h) were better predictors of N availability as compared to 0.5 and 1 h.
The E3 center in zinc oxide: Evidence for involvement of hydrogen

Proton implantation is shown to increase the concentration of the so called and commonly observed E3 defect level in zinc oxide (ZnO). Box and single profiles of protons with doses ranging from 6×1010 cm−2 to 4.3×1012 cm−2 were implanted into hydrothermally grown ZnO samples with original concentrations of E3 below 5×1014 cm−3. Capacitance-Voltage profiling and junction spectroscopy measurements showed that the charge carrier concentration and absolute concentration of E3 centers increase by more than one order of magnitude compared to the as-grown samples as well as control samples implanted with He ions. The results provide strong evidence for the involvement of H in the formation of the E3 center, and a complex involving interstitial H and an oxygen sub-lattice primary defect are discussed.
Effect of a variable solute distribution coefficient on mass separation in hollow fibers

The effect of a variable solute distribution coefficient on mass transfer in a hollow fiber separator is analyzed. This problem arises when liquid membranes are utilized in porous hollow fibers for mass separation. An example is the removal of toxic phenolic solutes from water. A variable solute distribution coefficient in the liquid membrane can have a significant effect on the separation performance of a hollow fiber module if the wall Sherswood number is less than 10. A distribution coefficient which increases with solute concentration gives increased mass transfer, and hence better separation, in comparison to a constant distribution coefficient. Vice versa, a distribution coefficient which decreases with solute concentration gives reduced separation in a hollow fiber module particularly in the inlet region of the module
Preparation of Poly(D,L-Lactide/Glycolide) Nanoparticles of Controlled Particle Size Distribution: Application of Experimental Designs

AbstractThis study investigates the use of the solvent evaporation method for preparing acid and glycolic acid-based copolymer nanoparticles. Initially, appropriate technological and formulation factors for elaboration of polymeric particles were selected by screening. Most favourable results were obtained using polyvinyl alcohol as a dispersing agent and a high pressure homogenizer to reduce the droplet size of the emulsion initially formed. On the basis of the conclusion thus drawn, a composite rotational experimental design was employed to evaluate the joint influence of three formulation variables (phase volume ratio of the emulsion formed, polymer concentration and homogenization pressure) on the micromeritic properties of the suspension finally obtained (mean particle size, coefficient of variation and polydispersity of the particle size distribution). Analysis of variance corresponding to the experimental design, showed a significant influence of the volume phase ratio and the polymer concentration.
Spin Coating Deposition of c-Oriented Wurtzite Gallium Nitride Thin Film

Spin coating growth and characterisations of c-oriented wurtzite structure gallium nitride (GaN) thin film on silicon (Si) substrate with (100) orientation was reported. The precursor solution consisted of a readily available gallium (III) nitrate hydrate powder, ethanol and diethanolamine as starting material, solvent and surfactant. All the structural and optical results showed that c-oriented wurtzite GaN thin film was deposited on Si (100) substrate. Compared with earlier reported work using sol-gel deposition, significant improvements in the structural quality of the GaN thin film were observed. The FWHM value of the thin film was approximately 2.60°. The framework described here is both an easy in setup and simple method as compared to other method such as MBE, MOCVD, and radio frequency sputtering to produce c-oriented wurtzite structure GaN thin film.
Computer simulation studies of diffusion in gels: Model structures

We have investigated particle diffusion through different obstacle geometries by computer simulations. The model structures used in this work — randomly placed point obstacles and cage-like structures — were chosen with the aim of represent a broad range of geometrical structures similar to gels and in order to be compared with our previous simulations of particle diffusion through polyacrylamide gels. The diffusion behavior was studied as a function of tracer size and obstacle concentration. The isomorphism between the diffusion of finite-sized tracers and the diffusion of point tracers in the presence of expanded obstacles was applied. Only hard-sphere interactions of the tracer with the immobile obstacles were considered and the theoretical description was made in terms of theory of the obstruction effect. In the case of randomly placed point obstacles an analytical expression for the dependence of the diffusion coefficient on tracer radius and obstacle concentration, applying the model of spherical cells, could be deduced. The same description was applied numerically to the other model systems. Up to moderatly high fractions of excluded volume this description was found to be successful. For very high fractions of excluded volume — higher concentrations or larger tracers — the validity of Fick’s second equation for describing diffusion breaks down and anomalous diffusion was found. The anomalous diffusion exponent diverges as the tracer size becomes comparable to the size of the pores. Analysis of the trajectory of tracers in the cases where an anomalous diffusion takes place shows a Levy-flight-like characteristic.
The crystal structures of the 1:1 complexes formed by hexamethylenetetramine with hydroquinone and resorcinol

Structural results for the hydroquinone complex (C6H 6O2.C6H~2N4) are compared with those already published. The differences between corresponding atomic fractional coordinates are normally distributed but the e.s. d. 's of these differences appear to have been underestimated by a factor of about 1.6. The resorcinol complex (C6H602.C6H12N4) is structurally closely related to the hydroquinone complex in spite of the fact that it crystallizes in a different crystal system. It has an orthorhombic cell, space group C2cm, with a = 10.344 (9), b = 7.080 (3), c = 16.835 (8) A, Z = 4. The structure was solved by comparison with that of the hydroquinone complex but could only be refined below R ~_ 0.28 for 398 reflexions by applying constraints to the dimensions of both types of molecule, when R fell to 0.11. Either the structure is disordered or the cell is a subcell corresponding to the superposition of portions of a larger true cell. The resorcinol and hexamethylenetetramine molecules are connected by O-H. N hydrogen bonds of length about 2.7 A.
Parcelamento da adubação nitrogenada na cultura do milho irrigado em sistema plantio direto

The purpose of this study was to evaluate the best time for application of N for an irrigated corn crop in a no-tillage system in the State of Alagoas. Three corn hybrids were used (TORK, FORT and BRS-3003) with four application times (days after sowing - DAS) for fertilizing with nitrogen as top dressing, consisting of the following treatments: 1) 120 kg ha-1 at 15 DAS, 2) 60 kg ha-1 at 15 DAS and 60 kg ha-1 at 30 DAS, 3) 120 kg ha-1 at 30 DAS, 4) 60 kg ha-1 at 30 DAS and 60 kg ha-1 at 45 DAS and 5) control treatment without N fertilization. The experimental design was in randomized blocks with four replications in a subdivided plot scheme. The components of the production studied were: final population of plants ha-1, numbers of corn ears ha-1 length of corn ears and number of rows of grains of corn and mass of 1000 grains. The productivities of grains obtained did not present significant differences among the treatments that received fertilization with nitrogen, independent of the time of application and number of split applications. It is concluded that in the no-tillage system in Alagoas spliting the manuring with nitrogen (top dressing) is not necessary.
CIVIC EDUCATION IN SECONDARY SCHOOLS: ITS IMMEDIATE VALUES AND LIFE-LONG IMPACTS

Civic education has been recognised as a compulsory school subject that exposes students to their rights, duties and obligations and how good citizens of a country should be ready to perform their civic responsibilities towards the growth and development of their society and the nation at large. Recently in Nigeria, a lot of political and economic problems such as kidnapping, killings, abductions, religious and ethnic rivalries with vandalism are very predominant and these had led to the re-introduction of Civic education. It is to ensure that students who have been taught their duties, rights and obligations, the nation’s values and constitution will become more responsible adults. This paper, therefore, takes an overview of Civic Education beaming searchlight on some contents that could correct socio-political anomaly and also brings to the fore two major problems confronting the subject in schools: inadequate manpower and rote learning method of teaching. This paper, therefore, posited that if Civic education is well taught in schools and teachers act as role models to students by exhibiting positive behaviour, the country would definitely become a better nation and indeed a just and egalitarian state.