Optimization of pH value and aluminium sulphate quantity in the chemical treatment of molasses

The aim of this investigation was to find the optimal working conditions for the chemical treatment of molasses that guarantee coagulation and precipitation of undesired macromolecules. Twenty experiments were performed, within the limits: 3.5pH8.5 and 0.1 mol Al/lc0.5 mol Al/l, on samples of molasses treated with Al₂(SO₄)₃ as a precipitant. The efficiency of the treatment was controlled through measuring both the zeta potential and solution absorbance at 560 nm. By analysing the experimental results, it was concluded that the optimum lies within reduced limits of: 4pH7 and 0.2 mol Al/lc0.4 mol Al/l, which covers nine experimental points. Based on these measurements, a mathematical model of absorbance changes was defined, in terms of pH and Al₂(SO₄)₃ quantity. The model was taken as the objective function, and the optimal calculated values were obtained: pH=5.3 and c=0.34 mol Al/l. They guarantee a minimal absorbance value of: 0.124 at 560 nm.     

A REGULARITY FOR CYCLIC CONJUGATION IN ACENAPHYHYLENE,FLUORANTHENE AND THEIR CONGENERS

Acenaphthylene, fluoranthene and their congeners are compounds that, in view of their chemical and physical properties, belong among benzenoid hydrocarbons. However, because of the presence of a five-membered ring, in all chemical-graph-theoretical considerations of benzenoid systems, these species have been disregarded. Continuing our recent studies of the title compounds, we report here on a peculiar characteristic of the pattern of their cyclic conjugation, named “the phenyl-cyclopentadienyl rule” (PCP rule): if a benzene ring is connected with the (unique) five-membered ring by exactly one carbon-carbon bond (which we refer to as a PCP constellation), then the cyclic conjugation in the five-membered ring significantly increases. If there are several PCP constellations, then the intensity of cyclic conjugation is additionally increased.     

Spray-dried nanoparticle-loaded pectin microspheres for dexamethasone nasal delivery

Abstract

In this study, we present the development of an innovative dry powder dexamethasone (Dex) nasal delivery system comprising Dex-loaded lipid/alginate nanoparticles incorporated within pectin microspheres (Dex/NPs-loaded pectin microspheres; DNM). DNM microspheres were characterized by the mean diameter of 2.76?±?0.10?µm, zeta-potential of –36.2?±?1.1?mV, and drug loading of 3.3?±?0.3%. The morphology study revealed irregular microsphere surface forming external voids. In contact with simulated nasal fluid, DNM microspheres demonstrated desirable property of moderate swelling and ensured stronger mucoadhesion compared with conventional Dex-loaded pectin microspheres. The strategy of Dex incorporation within the lipid/alginate NPs resulted in prolonged Dex release in relation to Dex being directly entrapped within the conventional pectin microspheres. DNM microspheres showed excellent biocompatibility and rendered Dex permeation across the selected epithelial cell model similar to that of Dex solution. In conclusion, balanced biopharmaceutical properties of the proposed nasal Dex delivery system provides the potential for prolonged contact time with nasal mucosa, prolonged therapeutic effect, and improved patient compliance.     

Impact of dynamic cross-saturation on accuracy of saturatedsynchronous machine models

Cross-saturation effect in synchronous machines has been a subject of considerable attention. Inclusion of the cross-saturation in the machine model has two consequences. The first one, called here “steady-state cross-saturation”, consists of dependence of the steady-state d-q axis magnetizing inductances on the currents in both axes. The second one, termed here “dynamic cross-saturation”, is the existence of nonzero elements in the system matrix, that describe cross coupling between d- and q-axis. Dynamic cross-saturation appears in all the saturated machine models, regardless of the selected set of state-space variables, with the exception of the winding flux linkage state-space model. The aim of this paper is to compare behavior of various models when dynamic cross-saturation is neglected. It is shown that the impact of dynamic cross-saturation on accuracy depends on the selected set of state-space variables. In the majority of cases omission of dynamic cross-saturation leads to very inaccurate results. However, it is found that for one particular class of models, omission of dynamic cross-saturation has practically no impact on accuracy. These models therefore fully describe the complete saturation effect by means of only continuous variation of the d-q axis magnetizing inductances     

Molybdenum carbide catalysts for water–gas shift

Molybdenum carbide (Mo₂C) was demonstrated to be highly active for the water–gas shift of a synthetic steam reformer exhaust stream. This catalyst was more active than a commercial Cu–Zn–Al shift catalyst under the conditions employed (220–295°C and atmospheric pressure). In addition, Mo₂C did not catalyze the methanation reaction. There was no apparent deactivation or modification of the structure during 48 h on‐stream. The results suggest that high surface area carbides are promising candidates for development as commercial water–gas shift catalysts. This revised version was published online in July 2006 with corrections to the Cover Date.     

Introduction

In the planning of a new passenger railway in Perth over many years, state agencies have actively pursued opportunities for transit-oriented development along its route. There is a strong policy framework demonstrating clear intent on the type of development required. Designing a transport system to compete with the car in an established low-density suburban environment has, however, raised some significant challenges for land-use planning. This article reports the results of research aimed at assessing changes in non-residential land use and the behavioural responses of local businesses in three emerging transit-oriented development precincts. It examines the first wave surveys of land use and businesses in 2006, the year before the railway opened, questioning the extent to which business has anticipated the new railway. The findings indicate that, despite good policy intent, planning in anticipation of the railway has been weak and insufficient attention was paid to implementation of important strategic planning principles and policies. While some land uses are compatible with transit-oriented development, these businesses employ small numbers, at odds with policies that required high trip generating development. Businesses have not shown a particularly strong interest in the new railway, their location decisions appear to reflect standard business practice rather than being influenced by opportunities created by the railway. There is a glimmer of anticipation—incoming businesses are more positive about the opportunities the railway may bring than those established in the station precincts before the 2001 railway route was announced. In particular, a significantly higher proportion of businesses in one case study station precinct are positive about opportunities created by the railway.     

Study of silicon photomultipliers fast amplifier and thermoregulation

The silicon photomultipliers (SiPM) are adopted in various physical applications, from medical physics to astrophysics, for their advantages in terms of cost and weight with respect to traditional photo detectors. Their low bias voltage supply (about 30 V), hardiness and resistance to magnetic field are ideal characteristics for space application. In the frame of INFN-Irst collaboration, some of them have been developed and produced at FBK (Trento-Italy), and have been characterized in the INFN laboratories of Bologna (DaSiPM2 collaboration).The SiPM can be used in conjunction with fibres and counters in high energy physics experiments. To exploit the SiPM time resolution, a fast amplifier has been studied. The SiPM gain depends critically on temperature and a thermal stabilization is also necessary. The use of a thermoelectric cooler module based on a Peltier cell has been investigated, and the results are shown.     

Situation and perspectives of waste biomass application as energy source in Serbia

The Autonomous Province of Vojvodina is an autonomous province in the Republic of Serbia. It is located in the northern part of the country, in the Pannonia plain. Vojvodina is an energy-deficient province. The average yearly quantity of the cellulose wastes in Vojvodina amounts to about 9 millions tons barely in the agriculture, and the same potential on the level of Serbia is estimated to almost 13 million tons. Only minor part of straw is utilized, and almost two-thirds are incinerated on fields owing to the problems during plowing under. The large sector in Serbia utilizes only about 15% of straw, while the individual one utilizes about 50% of straw and 20% of cornstalks. Environment pollutions, abandonment of the utilization of at least of one-third of the yield and extermination of the natural resources, primarily of humus, represent very adverse results of such procedures. Main problems with respect to the profitable usage of straw and other post-harvest residues are high expenses of their collection (collecting, balling or some other manner of compression), transportation from production- to the usage cites, as well as their handling and storaging. The agricultural production in Serbia should be based on the system of farms. For the efficient farming, it is obvious to organize life of producer and of his family immediately close to the production capacities. For the agriculture development, it is obvious to create a system of premiums, efficient crediting and the elaborated tax system that could create a basis for the certitude of work, confidence and constant growth of production, together with the mentioned and other measures. As the result of the activities oriented to substitution of the classical energents with energy obtained from biomass, farm that is in a higher degree energetically independent should be created. In such case, farms should apply the basic principles of the cleaner manufacturing, as an integral part of the concept of the sustainable development.     

Partial error tolerance for bit-plane FIR filter architecture

Whereas some applications require correct computation many others do not. A large domain where perfect functional performance is not always required is multimedia and DSP systems. Relaxing the requirement of 100% correctness for devices and interconnections may dramatically reduce costs of manufacturing, verification, and testing. The goal of this paper is to develop a method for trading computational correctness for an additional chip area involved by fault-tolerance implementation. The method is demonstrated for the BP array in the following way: only the most significant bits of the output word are made fault-tolerant. By introducing the concept of partially error-tolerant BP array, designers achieve one more degree of tradeoff freedom. Formal definitions of the proposed terms are given. A mathematical path based on transitive closure that generates an error significance map for the BP array is proposed. The design tradeoff is demonstrated through FPGA implementation. The achieved area savings are presented as a function of a number of most significant fault-tolerant bits.