Über die Veränderung der Sterine in Fetten und Ölen bei der industriellen Bearbeitung derselben II

Alteration of Sterols in Fats and Oils During the Industrial Processing Nonpolar steroids are formed by the action of bleaching earth on cholesterol, β-sitosterol, stigmasterol and brassicasterol in the presence of hexane. The hydrocarbons formed were isolated and investigated by column chromatography and preparative thin-layer chromatography. The hydrocarbons formed by the action of activated bleaching earth on cholesterol were repeatedly crystallized from ethyl alcohol and identified as Δ^3,5-cholestadiene.     

Evaluation of time-weighted total-square integrals

An efficient method for evaluating time-weighted total-square integrals is presented. The method is based on inverting two matrices.     

Solubilization of Paracetamol Using Non-Ionic Surfactants and Co-Solubilizers

The influence of certain aqueous non-ionic surfactants, cosolvents and cosolvent - surfactant blends on the enhanced solubility of paracetamol were studied. Dielectric constants of these solvent systems with and without paracetamol were determined. In several instances, paracetamol was increased in solubility by 5-7 fold, depending on the system used. Dielectric constants were affected to varying degrees by these systems.

The cosolvents, propylene glycol and glycerin apparently suppress micelle formation.     

Bioavailability of Hydrochlorothiazide Suspension

Flocculated and deflocculated suspensions of hydrochlorothiazide stabilized with certain natural stabilizers, some earthy silicates and one member of carbomers were submitted for dissolution studies in simulated gastric juice. Also, the flow rate, PH, sodium and potassium content of urine of five human volunteers administering the drug suspensions were determined as well. The correlation between the dissolution rate and the pharmacologic response of the drug suspensions was declared.     

Valorisation of olive mill wastewater by enhancement of natural hydroxytyrosol recovery

Recovery of natural and simple phenolic compounds with high added value was performed successfully from olive mill wastewater. Three types of olive mill wastewater were assayed in bioconversion at 15 and 40 L in mechanically stirred systems for 2 h at 50 °C. Maximum hydroxytyrosol concentrations of about 1.53, 0.83 and 0.46 g L^?1 were obtained in the presence of 5 IU Aspergillus niger β‐glucosidase per milliliter of OMW in North OMW, MSP and MCC, which were 2.70‐, 1.38‐ and 1.77‐fold higher than the controls, respectively. Enzymatic pretreatment was followed by two tangential flow membrane separation steps, microfiltration (MF) and ultrafiltration (UF), and concentration procedures for the ultrafiltration permeate. The latter exhibited a COD level of 48.44 g L^?1. The UF permeate concentration increased the hydroxytyrosol concentration to 7.2 g L^?1. Hence, this innovative work described an environmently friendly process; pilot‐scale has allowed producing a new and natural product which obeyed the dietary requirements; it contains some minerals beneficial to health and does not contain heavy metals or chemicals. Overall, this chemical‐free large‐scale process proved efficient for recovery of natural hydroxytyrosol.     

WETTABILITY MEASUREMENTS ON COAL PARTICLES BY MEANS OF THE SOLIDIFICATION FRONT TECHNIQUE

Reliable methods for the characterization of the surface properties and the wettability of small particles have not been available in the past. A novel technique, based on the behaviour of the lest particles at the solidification front of certain well defined solidifying melts (matrix materials) has been developed recently in our laboratory. This method was used to determine contact angles and surface tensions of coal particles in the range of 20-250 μm. Two types of bituminous and one type of subbituminous coal were tested using thymol, biphenyl, napthalene, salol and 2-phenyl phenol as matrix materials.

The results show that contact angles on small particles can be determined to within ± 2°, i.e. to the same degree of accuracy that is typically reported for extended smooth surface by means of conventional techniques. The measurements also show that within one and the same coal sample the larger particles are somewhat more hydrophilic than the smaller ones. Surface tensions and contact angles of coal particles are of great interest in connection with coal beneficiation processes such as froth flotation and oil agglomeration.     

Fault detection using robust multivariate control chart

We introduce a new multivariate statistical process control chart for fault detection using robust statistics and principal component analysis. The proposed approach consists of two main steps. In the first step, a robust covariance matrix is determined using the minimum covariance determinant algorithm. In the second step, an eigen-analysis of the robust correlation matrix is performed to derive the robust control limits of the proposed multivariate chart. Our experimental results illustrate the much better fault detection performance of the proposed method in comparison with existing statistical monitoring and process controlling charts.     

Stress and microstructure evolution in thick sputtered films

Materials synthesized by deposition techniques are often plagued by high levels of residual stress. While the origin and control of this stress in thin (sub-micron) films has been an active area of research, it is not clear how the results extrapolate with thickness. In the present work, in situ residual stress measurements are performed during the sputter deposition of beryllium, spanning the transition from thin to thick. Variables including sputtering gas pressure and substrate biasing are shown to strongly affect both the average and instantaneous stress levels measured during film growth. Detailed microstructural characterization is performed to assess the grain structure, surface morphology, and crystallographic growth texture of representative specimens. The microstructure is correlated with theoretical models of stress generation to interpret experimental measurements. A stress map is also constructed, generalizing the effects of processing and material parameters on stress state.