in this work, hydrochloric acid is used to remove iron impurities in the bauxite ore contained in the diasporite mineral located in the sari region. the bauxite ore was calcined at different temperatures and times, and then dissolved in a hydrochloric acid solution. after determining the optimum calcination conditions in 1 h at 900 °c, the response surface methodology (rsm) with four factors in...

This Issue Brief examines the experience of a particular large employer, and a subset of its employees, with respect to a recent increase in the number of health plans that employees could choose. In 2014, this employer offered employees a choice of four health plans― an HSA-eligible health plan, an EPO, a PPO, and an HMO―all with the same carrier. In 2015, it added six new health-plan choices―...

A robust approach should be considered when estimating regression coefficients in multi-response problems. Many models are derived from the least squares method. Because the presence of outlier data is unavoidable in most real cases and because the least squares method is sensitive to these types of points, robust regression approaches appear to be a more reliable and suitable method for addres...

[1] Comparison of ocean buoy measurements with infrasonic array data collected during the epic winter of 2002–2003 shows a clear relationship between breaking ocean wave height and infrasonic signal levels. In addition, infrasonic arrays allow the identification of distinct breaking zones along the shoreline. Our observations suggest that infrasonic measurements can be used in conjunction with ...

this paper presents a robust controller design methodology for a class of linear uncertain multivariable systems with hard time-domain constraints on their outputs and control signals in response to step disturbance inputs. in this approach, the m×m mimo system is replaced by m2 siso systems and then, using the qft technique, desirable controllers are synthesized. the final controller will be d...

The aim of the present work was to statistically design an autotrophic medium for maximum biomass production by Chlorella pyrenoidosa using response surface methodology. After evaluating one factor at a time approach, K2HPO4, KNO3, MgSO4.7H2O and NaHCO3 were preferred over the other components of the fog’s medium as most critical autotrophic medium components. The study showed that the maximum ...

in this work, response surface methodology (rsm) and artificial neural network (ann) were used to predict the decolorization efficiency of reactive red 33 (rr 33) by o3/uv process in a bubble column reactor. the effects of four independent variables including time (20-60 min), superficial gas velocity (0.06-0.18 cm/s), initial concentration of dye (50-150 ppm) and ph (3-11) were investigated us...

a soil bacterium capable of degrading chitin on chitin agar plates was isolated and identified as bacillus pumilus isolate u5 on the basis of 16s rdna sequence analysis. in order to optimize culture conditions for chitinase production by this bacterium, a two step approach was employed. first, the effects of several medium components were studied using the plackett-burman design. among various ...

a hydrothermal method for preparation of nano-size zirconia has been studied to optimize the effective parameters (precursor concentration, temperature and time) using response surface methodology (rsm). the synthesized zirconia samples were characterized through x-ray diffraction (xrd), scanning electron microscope (sem) and transmission electron microscopy (tem) analyses to identify mean nano...

sclerotinia stem rot (ssr), caused by sclerotinia sclerotiorum, is one of the most important diseases of canola (brassica napus) in golestan province, the leading canola producer in iran. in order to assess the yield loss of canola caused by ssr, 80 fields were surveyed in four different regions of the province (gorgan, ali abad, kalaleh and gonbad) during 2006-2007, and ssr intensity was recor...