Possibility of using chemical fertilizers instead of 9K medium in bioleaching process of low-grade sulfide copper ores

The possibility of applying chemical fertilizers as a source of nutrients for bacterial growth in bioleaching process was investigated. In the first part of the experiment the nutrient content of four sulfide copper ore samples was determined. The results confirmed that the amount of calcium, magnesium and sulfur were sufficient to support bacterial growth, whereas nitrogen, phosphorous and potassium were not sufficient. Therefore, N, P, and K from a chemical fertilizer source were applied to the sulfide copper ores to make a cost-effective bioleaching process. According to shake flask experiments by using mesophilic, iron-sulfur oxidizing bacteria, bacterial activity and copper recovery in some proposed media was satisfactory compared to 9K medium. Additionally, potassium had positive effect on the copper ore bioleaching while NO₃⁻ and Cl⁻ had inhibitory effect on the bacterial activity.     

Sentic PROMs: Application of sentic computing to the development of a novel unified framework for measuring health-care quality

Barriers to use health related quality of life measuring systems include the time needed to complete the forms and the need for staff to be trained to understand the results. An ideal system of health assessment needs to be clinically useful, timely, sensitive to change, culturally sensitive, low burden, low cost, involving for the patient and built into standard procedures. A new generation of short and easy-to-use tools to monitor patient outcomes on a regular basis has been recently proposed. These tools are quick, effective and easy to understand, as they are very structured and rigid. Such structuredness, however, leaves no space to those patients who would like to say something more. Patients, in fact, are usually willing to express their opinions and feelings in free text, rather than simply filling in a questionnaire, for either speaking out their satisfaction or for cathartic complaining. Sentic PROMs allow patients to evaluate their health status and experience in a semi-structured way and accordingly aggregate input data by means of sentic computing, while tracking patients’ physio-emotional sensitivity.     

On reducing computational effort in topology optimization: how far can we go?

An approximate approach to solving the nested analysis equations in topology optimization is proposed. The procedure consists of only one matrix factorization for the whole design process and a small number of iterative corrections for each design cycle. The approach is tested on 3D topology optimization problems. It is shown that the computational cost can be reduced by one order of magnitude without affecting the outcome of the optimization process.     

A frame-based approach for wideband correlation-inversion of lossless scatterers

Presented here is an ultra-wideband-correlation-based scheme for imaging and inversion of an unknown weak and lossless scatterer embedded in a known background medium. The scheme uses an excitation and reception of ultra wideband/short-pulsed fields by an array of transducers located outside the imaging domain. The scatterer image is formed by cross correlating (in the short-pulsed domain or via spectral integration in the ultra wideband domain) the numerically/ analytically back-propagated, measured, and scattered data set with the forward-propagation excitations. It is shown that in the ultra wideband domain, the forward-backward propagation functions form a frame set in a finite Hilbert space. Within the weak scattering assumption (Born approximation) the scatterer's image and object function (velocity profile) are related via the corresponding frame operator. Therefore, an exact inversion scheme of the frame operator is readily available to yield the object function via an iterative scheme or using the dual frame set. Numerical examples that demonstrate the performance of the imaging and inversion schemes for scatterers with various velocity profiles are presented. It is shown that the scatterer image is generally of poor resolution. However, on inversion, a high-quality velocity profile is obtained that captures the scatterer fine details.     

Reconstruction of a fiber Bragg grating from noisy reflection data

We develop a novel method that enables one to reconstruct the structure of highly reflecting fiber Bragg gratings from noisy reflection spectra. When the reflection spectrum is noisy and the grating reflectivity is high, noise in the Bragg zone of the reflection spectrum is amplified by the inverse scattering algorithms and prevents the reconstruction of the grating. Our method is based on regularizing the reflection spectrum in frequencies inside the Bragg zone by using the data on the grating spectrum outside the Bragg zone. The regularized reflection spectrum is used to reconstruct the grating structure by means of inverse scattering. Our method enables one to analyze gratings with a high reflectivity from a spectrum that contains a high level of noise. Such gratings could not be analyzed by using methods described in previous work [IEEE J. Quantum Electron. 39, 1238 (2003)].     

Physical properties of normal grade biodiesel and winter grade biodiesel

In this study, optical and thermal properties of normal grade and winter grade palm oil biodiesel were investigated. Surface Plasmon Resonance and Photopyroelectric technique were used to evaluate the samples. The dispersion curve and thermal diffusivity were obtained. Consequently, the variation of refractive index, as a function of wavelength in normal grade biodiesel is faster than winter grade palm oil biodiesel, and the thermal diffusivity of winter grade biodiesel is higher than the thermal diffusivity of normal grade biodiesel. This is attributed to the higher palmitic acid C(16:0) content in normal grade than in winter grade palm oil biodiesel.     

Fenton digestion of milk for iodinalysis

Iodine is an essential micronutrient especially important in the neurodevelopment of infants. Spot samples of urinary iodine (UI) are used as an epidemiologic index of adult iodine nutrition. Individual infant iodine nutrition is of vital importance, but infant urine is difficult to collect, much less a 24 h sample. Monitoring the intake provides a pragmatic solution for determining infant iodine nutrition. Because of the high solids content of milk and the possible existence of iodine in an organically bound form, sample digestion is obligatory. The U.S. Food and Drug Administration, for example, uses wet ashing by HClO(4); special precautions and fume hoods are required. We present a method of Fenton digestion of human and bovine milk samples and infant formula. No specialized equipment or hazardous reagents are used; measurement is made by isotope dilution inductively coupled plasma mass spectrometry. In Fenton digestion, Fe(II) and H(2)O(2) oxidizes the sample. In an interlaboratory study, excellent agreement (r(2) = 0.9934) was observed with results obtained by HClO(4) digestion and Sandel-Kolthoff kinetic colorimetry. Average recoveries of iodide, triiodothyronine, and thyroxine ranged between 100% and 101%. Following digestion, iodine was found to exist entirely as iodide. Control of pH is imperative if loss cannot be corrected for by isotope dilution. Loss was below 20% for all samples when the pH was between 2.25 and 2.5.