bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of Magstream in Mineral Sands Separation
Authors: Kojovic T.
Published: September 2007

The Magstream separation process, developed by Intermagnetics
General corporation, offers an alternative method for both laboratory and
plant mineral separations. It is based on the concept of using a fluid whose
effective density is magnetically derived. The separator can be applied to
both purely gravimetric separation of non–magnetic materials and
magnetic–gravimetric separation of paramagnetic material.

The separation density can be easily adjusted by changing the speed of
rotation or process fluid concentration. A separation band can be drawn on
a plot of particle density and magnetic susceptibility to illustrate the
separation of particles that would be achieved. The process fluid is a
non–toxic, water–based bio–degradable magnetic fluid, and relatively
inexpensive compared to heavy liquids and sodium polytungstates.

The Model 100 separator available at the Julius Kruttschnitt Mineral
Research Centre is portable and suitable for analysing small batch samples.
The separator selectivity is at best ± 0.1 SG units, which may cause a lower
grade of products in separations of materials with a small SG differential.

The separator has been evaluated for mineral sands applications. Several
good applications of Magstream have been identified. Particularly effective
separations were quartz/heavy mineral concentrate, kyanite/zircon,
monazite/zircon and rutile/zircon (multiple passes required).

This paper describes the Magstream process, operation, the mathematical
model of separation, and presents the results of the separation case studies
in detail.
Theoretical Principles, Present Status and Prospects for Development of Material Separation in Magnetic Fluids
Authors: Gubarevich V. N. , Vidsota S. V.
Published: September 2007

This paper reviews theoretical principles of material separation in
magnetic fluids according to their density. The main formulae and
expressions are summarised and possible prospects for development of this
relatively young branch of separation are indicated. Specifications are given
for separators of this type, as designed over the last several years by the
Lugansk Institute "Gipromashugleobogaschchenie". Practical experience
obtained in the Institute is outlined.
Investigation of the Removal of ASH, Sulphur and Other Contaminants From Coal by Wet Magnetic Separation
Authors: Karmazin V. I. , Mostika Yu. S. , Savluk E. N.
Published: September 2007

This paper presents the results of wet magnetic beneficiation of
finely ground coals by high–gradient magnetic separation, with the aim to
remove deleterious and toxic impurities.
A Study of Matrices for High–Intensity Magnetic Separators
Authors: Maly V. M.
Published: September 2007

This paper summarises the results of the research carried out, for
the last 15 years, by the Department of Separation of Weakly Magnetic
Ores of the Mekhanobrchermet Institute, Krivoy Rog, Ukraine, on the
matrices of high–intensity magnetic separators foe beneficiation of weakly
magnetic iron ores and other weakly magnetic materials.
The Removal of Iron From Hard Pulverised Kaolin by Dry High–Gradient Magnetic Separation
Authors: Chun Yu Kang
Published: September 2007

Deposits of hard kaolin are abundant in China, with kaolin
content in the ore exceeding 95%. It is, however, rather difficult to remove
iron from the ore. It was demonstrated that wet high–gradient magnetic
separation is very efficient in removing the iron compounds from kaolin.
For hard kaolin, however, dry high–gradient magnetic separation (HGMS)
may be more suitable. To this end, we have developed a new type of dry
HGMS device for laboratory use. The separation performance of the device
was tested as a function of the iron concentration in the ore, gas velocity,
magnetic induction and the intensity of the vibrating current. The following
results were achieved: for sample no. 1 of hard kaolin, the content of Fe2O3
was reduced from about 2.20% to .082%, with the yield of the concentrate
of 86.5%. For no. 2 sample of hard kaolin, the content of Fe2O3 was reduced
from about 0.60% to 0.48%, with the yield of the concentrate 83.15%. The
removal of the iron oxide from hard kaolin by dry HGMS proved to be
feasible. Industrial–scale dry HGMS device was built and installed at a
mine at the end of 1993.
The Motion of Mineral Sand Particles on the Roll in High Tension Separators
Authors: Edward D. , Holtham P. N. , Kojovic T.
Published: September 2007

A number of models of the high tension roll separator have been
described in the literature. All the models, in their calculation of the
centrifugal force component of the force balance, appear to assume that
particles introduced onto the top of the roll instantaneously reach roll
speed. This paper questions that assumption. A theoretical analysis of the
forces involved suggests that particles almost certainly do not reach roll
speed (even if they have been charged in a corona field) until they have
been carried a considerable distance with the roll. Experimental evidence
was found to confirm the theoretical analysis, with 150 – 180 μm zircon
particles having a speed of 180 rpm after travelling 55 degrees on a roll
revolving at 275 rpm.
Recent Activities in Magnetic Separation in Sweden
Authors: Wang Yanmin , Forssberg Eric
Published: September 2007

This paper describes some industrial applications of magnetic
separation in Swedish mineral industry. Recent studies on magnetic
treatment of minerals in Sweden are also presented. These studies involve
selectivity of wet magnetic separation, wet magnetic recovery of mineral
fines and ultrafines, sulphide processing by magnetic means, as well as dry
magnetic purification of industrial minerals.
Theoretical Model of Separation of Fine Particlesin a Rotating Ferrofluid
Authors: Mockovčiaková Annamária , Lovás Michal , Jakabský Štefan
Published: September 2007

The application of centrifugal forces to a ferrofluid with finely
grained particles located in a non—homogeneous magnetic field is the basis
of the theoretical model of separation outlined in this paper. An analytical
solution of the equation of the particle motion, its application under certain
conditions, as well as the graphic representation of the results are
presented.
Microwave Pretreatment of Coal Prior to Magnetic Separation
Authors: Butcher D. A. , Rowson N. A.
Published: September 2007

New methods to reduce the total sulphur content of coals are
being developed since the introduction of legislation requiring cuts in
sulphur emissions to the atmosphere. It is known that weakly paramagnetic
pyrite (FeS2) particles are difficult to remove from clean coal by standard
magnetic separation techniques. Data is presented here comparing standard
magnetic separation tests to results achieved when the coal is subjected to a
caustic microwave leach pretreatment, prior to conventional dry magnetic
separation. A significant increase in the removal of total sulphur is observed
when this pretreatment is applied to the coal.
The New Medium–Intensity Drum–Type Permanent MagneticSeparator Permos and its Practical Applications forthe Processing of Industrial Mineralsand Martitic Iron Ores
Authors: Wasmuth H. –D.
Published: September 2007

KHD Humboldt Wedag AG developed an improved version of a
drum–type magnetic separator PERMOS with special magnetic field
configuration for the NdFeB permanent magnets which is giving the
magnetic field strength of 0.7 Tesla and a wide working range outside the
drum. The magnet system within the PERMOS unit is no longer made of
relatively large magnet blocks of alternate radial magnetisation; the system
is now made up of a multitude of small NdFeB bars with a specially
oriented magnetisation. This open‐gradient magnetic separator can be used
for dry magnetic separations in “top–feed” or “free–fall” feed configuration
as well as in the conventional wet “drum–type” feed mode. It allows high
throughput rates of up to 40 tonnes of solids per hour per meter of the drum
length without any dogging problems in case of higher magnetite content in
the feed material. Important design features and the actual machine
characteristics of the improved PERMOS units for dry and wet magnetic
separation are described and typical examples for their commercial
application for industrial minerals and for martitic iron ores are presented.
Method and Equipment for Final Concentration of the Gold–Bearing Alluvial Sands
Authors: Gubarevich V. N.
Published: September 2007

The article describes equipment designed for final concentration
of gold–bearing heavy concentrates. Final concentration is performed with
a complex dry method: separation in weak and strong magnetic fields to
remove metal inclusions and weakly magnetic minerals from the heavy
concentrates, followed by separation of non–magnetic minerals in a
magnetic fluid according to their density. This method of final
concentration of the gold–bearing concentrates allows to successfully
replace the amalgamation process used at present. In one application the
final concentrate with the grade of 452 kg Au/tonne, and with the recovery
of 95.5% was obtain from the black sand assaying 473 g Au/tonne.
Development and Applications of a Drum Medium–IntensityPermanent Magnetic Separator
Authors: Liang Cao Zhi
Published: September 2007

This paper describes the development and testing of a drum medium—intensity
permanent magnetic separator. The magnetic field strength on the drum surface
can be increased to 0.8 T using a new magnet technology. Uniform distribution of
a feed can be achieved with a two—stage feed system. Industrial tests were carried
out using a manganese mineral from DouLan manganese mine. The results
obtained show that good separation results can be obtained using the separator,
with upper limit of the separation size being 30 mm.
Mineral Processing of a Converter Slag and Its Usein Iron Ore Sintering
Authors: Radosavljevic Slobodan , Milic Dragan , Gavrilovski Milorad
Published: September 2007

During the production of steel by a converter process, a slag is produced and
stored at slag depots, thus causing serious difficulties through pollution and space
requirements. A converter slag is a compact and abrasive raw material containing
CaO and Fe. The investigations showed that a multi—stage crushing, classifying
and magnetic separation operations influence successful steel recovering from slag,
while slag itself is converted into a high—grade fluxing agent which can be used in
production of sinter and raw iron. Also, positive economic effects are achieved
through a partial substitution of more expensive limestone and a full substitution
of Mn—ore and dolomite.
Wet High Intensity Magnetic Separation of Iron Minerals
Authors: Shao Y. , Veasey T. J. , Rowson N. A.
Published: September 2007

Four different iron minerals were selected for study, and five size fractions
of each mineral were prepared. The magnetic properties of these minerals
were measured. The effect of particle size and magnetic susceptibility on
wet high intensity magnetic separation was studied simultaneously. It was
found that hematite—1 was a strongly paramagnetic mineral, and the effect
of particle size in WHIMS was not significant. Goethite and limonite were
weakly paramagnetic minerals, and could not be effectively recovered by
WHIMS. The magnetic properties of hematite—2 were between hematite—1
and goethite and limonite, and the effect of particle size on WHIMS for
hematite—2 was significant.
The Effect of Irrigation With MagneticallyTreated Water on The Translocation ofMinerals in The Soil
Authors: Noran Rami , Shani Uri , Lin Israel
Published: September 2007

Magnetically treated water (MTW) is water passed through a
magnetic field before being used. Applications of MTW are abundant in
industry where it is used to prevent scaling on inner walls of pipes
conveying fluids, especially water. In recent years scientists investigating
the subject have concluded that the magnetic field interacts with the
surface charges of particles in the fluid solutions affecting the crystallisation
and precipitation of the solids in them. These processes are of significant
effect on the translocation of minerals in irrigated soil.

In this work the concentrations of K, N, P, Na and Ca+Mg, as well as the
total mineral content in the MTW—irrigated soil were compared with the
same data in soil irrigated with ordinary water. The soil was sampled at
three different locations at three different distances from the dripper line,
representing three different leaching states of the soil. Differences in
concentrations were found in at least one of the three locations with
respect to each mineral and including the total mineral content. Most of
the differences appeared in the less leached parts of the soil, in the bed
margin. It appears that there is a general tendency of minerals to
precipitate out of the solution faster in MTW conditions.
A Study of the Conditions of Maximum Filtration Efficiencyfor a HGMF‐Axial Magnetic Filter Cell With Bounded Flow Field
Authors: Badescu V. , Murariu V. , Rotariu O. , Rezlescu N.
Published: September 2007

The theory of magnetic particles′ capture on a HGMF‐axial
magnetic filter cell with bounded flow field is presented. The equations of
particle motion for both potential and laminar flow are obtained. By analytical
solving of these equations, the trajectories of particles are established. The
flow velocity of the fluid suspension for the case of potential flow is set equal
with the velocity averaged across the tube section for the laminar flow. Thus,
it is possible to make a comparison between the capture process in laminar
and potential flows. The capture time and the capture cross‐section are
calculated. Finally, a criterion for maximum filtration efficiency is presented.
Theory and Performance of a Slurry Flow in Form of a Film in the 6ERM–35/315 SeparatorWith a High—Gradient Magnetic Field
Authors: Turkenich A. M.
Published: September 2007

The physical foundations and theoretical determination of conditions for
formation of a slurry flow in form of a film along ferromagnetic plates of a
rotary high—gradient magnetic separator are described. It is shown that
this new hydrodynamics allows to increase not only the reliability of the
separator thanks to the increase of the width of gaps between the plates,
but also to improve its metallurgical efficiency.
The Effect of Air Friction in Electrostatic Separation
Authors: Fonseca Ilídio A. B.
Published: September 2007

This paper presents the results of a Ph.D. research program undertaken by the
Author at the Mining Engineering Department of Oporto University. This was a
part of a continuing team effort to develop modelling and computational ideas
and tools for the mineral processing industry, based on mathematical
descriptions of the state of liberation of a comminuted mineral mass. It focuses
on the effects of air friction on the metallurgical parameters affecting an
electrostatic separation process and on their practical implications, mainly as
regards the needs for previous sizing of the feed.
Improving Grade of Indian Chromite Ores by High–Gradient Magnetic Separation
Authors: Rao R. Bhima , Das B. , Sastri S. R. S.
Published: September 2007

Investigations were carried out to improve the chromium–to–iron ratio of
two off–grade chromite samples from Orissa, India, having different
physical natures. The results of these investigations indicated that the
chromium–to–iron ratio could be improved from 1.85 to 3.0 with around
10% to 30% recoveries by high–intensity magnetic separation of the washed
ores. A common flowsheet is suggested for processing of these two ores.
A Study of Magnetic Aggregation—Gravity Separation for Separation of Coarse Magnetite Ores
Authors: Yu–Shu Zhang , De–Zhang Luo , Shuyi Liu
Published: September 2007

This paper describes experiments on separation of coarse magnetite ores
using magnetic aggregation—gravity separation (MAGS) process for the first
time. The results show that the MAGS technology can have a coarser
separation size as well as a higher grade of the the magnetic product than
the traditional low—intensity magnetic separation technology.
Development and Commercial Test of Slon–2000 Vertical Ring and Pulsating High–GradientMagnetic Separator
Authors: Da–He Xiong
Published: September 2007

Slon–2000 vertical ring and pulsating high–gradient magnetic separator is
an efficient industrial equipment for processing weakly magnetic minerals.
It has been recently developed at the Ganzhou Non–Ferrous Metallurgy
Research Institute. A six–month commercial testwork to process low–grade
hematite ore was completed in Chong Changeling Mineral Processing Plant
in 1995. compared with WHIMS–2000 wet high–intensity magnetic
separator, the grade of the concentrate is by 7.21% higher the grade of the
tailings lower by 5.41% and the iron recovery higher by 7.36%. Particularly,
the matrix is always clean so that the matrix clogging usual in the WHIMS –
2000 machine has been overcome.
The Effect of Pretreatment on Magnetic Separation of Ferruginous Minerals in Bauxite
Authors: Rao R. Bhima , Besra L. , Reddy B. R. , Banerjee G. N.
Published: September 2007

Bauxite sample of Jamnagar, India, is suitable for refractory applications
after separation of iron minerals. Different magnetic separators and
intensities are studied on different treated samples. The results of these
investigations indicate that removal of ferruginous minerals from crude
sample requires a magnetic intensity of 14 000 Gauss. The calcined sample
at 800℃ requires magnetic intensity of about 7000 Gauss, whereas the
reduced bauxite needs less than 2000 Gauss for separation of iron and the
product achieved contains 76% Al2O3 with 62% iron removal and 69%
Al2O3 recovery. All these products are suitable for refractory applications.
Feed Preparation Factors Affecting the Efficiency of Electrostatic Separation
Authors: Lindley K. S. , Rowson N. A.
Published: September 2007

This paper outlines various feed preparation variables which can affect the
separation efficiency and operating parameters of an electrostatic
separation. Factors considered include physical and chemical conditioning
of feedstocks prior to separation. The effect of particle size and shape on
separation is evaluated along with operating temperature and humidity.
The Use of Physical Methods in Treating Raw Materials of the Banská Štiavnica Region
Authors: Leško Michal , Búgel Milan , Zelenák Fridrich
Published: September 2007

Laboratory experiments on beneficiation of feldspar using physical methods
are described. The results of the tests in which table, magnetic and
electrical separations were used show that it is not possible to reduce the
concentration of iron in the final product below 1%. It is thus clear that
physico—chemical techniques must be applied.
An Approach to Reduce Load on the Acid Leaching Circuit of the Commercial Uranium Recovery Plant at Jaduguda, India
Authors: Rao G. V. , Prakash S.
Published: September 2007

The commercial uranium recovery plant at Jaduguda, Bihar, India, currently treats
around 900 tonnes of ore per day from the Jaduguda mine, containing around 0.05%
U3O8. Subsequent to removal of the sulphide minerals present in the ore by flotation,
nearly 95% of the tailings are being treated in the acid leaching circuit to recover the
uranium values. Laboratory investigations on the bulk flotation tailings revealed that
around 63% of the uranium values are associated with feebly magnetic material of the
tailings. The magnetic product obtained on wet high intensity magnetic separator gave
rise to a product containing 0.1% U3O8. The rest of the uranium values were found to get
enriched to 0.15% U3O8 in the –20 µm fraction of the non‐magnetic material thereby
giving scope to retrieve the uranium values by recovering the slimes. Necessary unit
operations needed to be introduced in the plant flowsheet to reduce load on the acid
leaching circuit of the commercial uranium recovery plant are discussed.
Enrichment of the Manganese Content by Wet High Intensity MagneticSeparation From Chikla Manganese Ore, India
Authors: Rao G. V. , Mohapatra B. K. , Tripathy A. K.
Published: September 2007

Manganese ores from Chikla region, Bhandara district, Maharastra, India, by and large
are low and medium grade types and need beneficiation to utilise them in ferromanganese
industry. Isodynamic separation followed by chemical characterisation of ores from this
region indicated their susceptibility to Mn enrichment. Details of characterisation, heavy
media and magnetic separation studies carried out on a medium grade manganese ore,
containing 44% Mn, 7.8% Fe and 22% acid insolubles, from the Chikla region are
presented. By processing the material on a wet high intensity magnetic separator, a
product with 51% Mn at 95% recovery could be obtained.
Grade and Recovery Prediction for Eddy Current SeparationProcesses
Authors: Rem P. C. , Beunder E. M. , Kuilman W.
Published: September 2007

Grade and recovery of eddy current separation can be estimated on the basis of trajectory
simulations for particles of simple shapes. In order to do so, the feed is characterized in
terms of a small set of test‐particles, each test‐particle representing a fraction of the feed of
a given size, shape and material. In this paper, the grade and recovery curve predicted for a
sample from the 6–16mm non‐ferrous fraction of car scrap is compared with experimental
data. The results indicate that it may be possible to automatically control eddy current
separators on the basis of such predictions.
Electrical Separation of Metals From Mineral Wastes Using Gradient Forces
Authors: Lungu Mihail , Schlett Zeno
Published: September 2007

This paper presents a method for recovery nonferromagnetic components
(Au, Ag) in reduced concentration from mineral wastes, using gradient forces.
First the main up‐to‐date electrical dry separation techniques for recovery
useful materials from wastes are presented which are based on different electrical
properties of the waste components.

Then, the main theoretical considerations reffering to electric gradient forces
(typical for nonuniform fields) are presented. The theory shows how these
forces together with other forces act on the particles of a mixture subjected
to the separation process. Owing to combined actions of all these forces a
superficial layer is obtained, consisting in metallic particles concentrated on
the surface of mixture. Finally, the experimental results are presented, based
on chemical analysis of the obtained superficial layer.
Does Magnetic Treated Water Affect Plants Via Soil Population?
Authors: Moran Rami , Shani Uri , Lin Israel J.
Published: September 2007

Magnetically treated water (hereinafter MTW) is water which has passed
through the core of a device which contains a permanent magnet. The way
MTW affects plants is not clear and one possibility is that MTW affects a
plant indirectly through its effect on the soil microflora/fauna population.
This theory was investigated with pepper and melon, plants which have
specific (and contradictory) responses to soil disinfection. Response to
MTW was observed in both crops unless soil was disinfected, thus
supporting the theory of the soil microflora/fauna being involved in the
MTW effect.
The Investigation of Separability of Particles Smaller Than 5 mmby Eddy Current Separation Technology. Part I: Rotating Type EddyCurrent Separators
Authors: Zhang Shunli , Rem Peter C. , Forssberg Eric
Published: September 2007

Owing to the growing emergence of the end‐of‐life electrical and electronic products with
complex material structures and an ever‐diminishing particle size of the valuable metals
involved, development of eddy current separators (ECS) has been targeting selective
separation of small non‐ferrous metal particles smaller than 5 mm. Separability of various
materials smaller than 5 mm, including fine copper wires, has been investigated using ECS
with various design concepts. The present research work is divided into two parts, with
Part focusing on the rotating type ECS which are today common in practice, and with
Part II dedicated to the ECS with novel concepts such as wet ECS technology. In Part I,
three rotating belted‐drum ECS were employed, which are manufactured by Bakker
Magnetics, the Netherlands, Huron Valley Steel Co., US, and Eriez Magnetics, UK
respectively. It is found that the belted‐drum ECS are effective for separating materials
below 5 mm if the magnetic drum rotates in opposite direction to the conveyor belt. The
separation principle, particularly the "backward phenomenon" of the rotating type ECS
for small particles has been unravelled in the present study. Moreover, separation of AI
from the 0–10 mm fraction of electronic scrap has been conducted. The results obtained
demonstrate that the belted‐drum ECS with appropriate design may be applicable for
separation of small aluminum particles from electronic scrap.
A Model of Multiple Magnetic Separation in the Continuous Process
Authors: Brożek M.
Published: September 2007

In continuous enrichment processes, in industrial conditions and due to the generally
required high efficiency of machines, a relatively high concentration of feed is applied.
Since it is necessary to liberate the useful minerals, the feed has to be ground thoroughly
and this fact results in the percentage growth of the fraction of particles measuring a few
tens or several micrometers. When the particles are so fine and the feed is so much concentrated,
the magnetic particles interactions play a significant role and they lead to the
phenomenon of magnetic flocculation. The flocs contain the particles of waste rock and
intergrowths. In order to obtain the final product of high quality the material is subjected
to multiple enrichment operations.
This paper presents a mathematical model of multiple magnetic separation in which the
grade of the magnetic concentrate was expressed as the function of multiplication ratio of
separation and the value of external forces acting on a particle as well as interactions of the
magnetic particles. The dependence of the content of magnetic component in the highgradient
separation concentrates on the multiplication ratio of separation, flow velocity of
the suspension through the separator working space, the intensity of matrix vibration and
the concentration of solid particles in the feed for the separation of magnetite ore was
verified. The verification was carried out according to the author’s own research and the
reference.
Magnetic Separation of Calcite Using Selective Magnetite Coating
Authors: Prakash S. , Das B. , Venugopal R.
Published: September 2007

Magnetic separation of naturally occurring calcite (98.2% CaCO3) using selective coating of
synthetic colloidal magnetite with sodium oleate has been investigated as a function of pH,
concentration of colloidal magnetite, magnetic intensity and particle size. Colloidal magnetite
treated with sodium oleate (oleate magnetite) is found to be a better coating agent than
the natural magnetite. The mechanism of oleate magnetite coating has been investigated
through adsorption and electrokinetics measurements. FTIR studies indicate that there is a
possible chemical interaction between calcite and magnetite surfaces on which sodium
oleate is adsorbed. Magnetic susceptibility measurement shows a finite susceptibility of
calcite by the addition of colloidal magnetite. In the investigation with calcite, calcite
recoveries of > 94% have been achieved at a colloidal magnetite concentration of 0.25 ml/g
and 7.1 kG of magnetic intensity. In case of synthetic mixture of calcite and quartz > 90%
calcite recovery at a grade of 80.9% CaCO3 has been achieved at the optimum pH of 11.
An Analytic Solution for the Torque Between Two Magnetic Dipoles
Authors: Landecker Peter B. , Villani Daniel D. , Yung Kar W.
Published: September 2007

An analytic equation describing the torque between two magnetic dipoles is derived in
this paper. We assume that the dipole sizes are small compared to their separation.
Based on a previously derived force calculation between two magnetic dipoles, we derive
an analytic expression for the torque. Note that the derived torque decreases with the
third power of the distance between the dipoles. It is also interesting to note that the
torque on the first dipole is not necessarily equal in magnitude and opposite in direction
to the torque on the second dipole. This is due to the torque of both dipoles about a
common center of mass.
Magnetic Fluids: Biomedical Applications and Magnetic Fractionation
Authors: Rheinländer Thomas , Kötitz Róman , Weitschies Werner , Semmler Wolfhard
Published: September 2007

In addition to engineering applications, magnetic fluids containing magnetic nanoparticles
are being increasingly applied to biomedical purposes. Besides the well established
use of magnetic particles for biological separation or as contrast agents for magnetic
resonance imaging, magnetic particles are also being tested for the inductive heat treatment
of tumors or as markers for the quantification of biologically active substances.
The properties of magnetic nanoparticles usually exhibit a broad distribution, so in
many cases upon application only a small fraction of the particles contribute fully to the
desired magnetic effect. Therefore, magnetic fluids have to be optimized by fractionation
techniques. This is preferentially achieved by methods that separate magnetic nanoparticles
in accordance with their magnetic properties. Hence, a magnetic technique has
been developed for the fractionation of magnetic fluids. Two different magnetic fluids
were fractionated by this method. The fractions obtained and the original samples were
characterized with respect to their magnetic properties as well as their particle sizes. They
were investigated not only in terms of their magnetization curves but also in respect to
biomedical applications. The magnetic fractions show clearly improved magnetic properties
compared to the original samples and are therefore especially suited for distinct
applications. Furthermore, the results indicate that the magnetic method fractionates the
particles in accordance with their magnetic moment and has a good reproducibility.
The Investigation of Separability of Particles Smaller Than 5mm by Eddy‐Current Separation Technology – Part II: Novel Design Concepts
Authors: Rem Peter C. , Zhang Shunli , Forssberg Eric , de Jong Tako P. R.
Published: September 2007

Separability and separation mechanisms of small particles in modern rotating type eddycurrent
separators (ECSs) were discussed in Part I. In order to address problems associated
with this design concept, a number of novel ECSs, each with a unique design, have
been developed. Part II reports on investigation into the separability and separation principles
for various materials smaller than 5 mm, including fine copper wires, in three new
devices: the redesigned Delft vortical ECS (VECS), prototype TNO ECS and a laboratory
wet ECS (WECS). It is found that TNO ECS and WECS are more practical tools for
separation of small metal particles. In particular, WECS is able to recover approximately
80% of very fine copper wires, with 0.5mm diameter and 2mm length. Separation principles
for WECS are discussed in greater detail than other design concepts in the present
study. It appears that the fledgling WECS will be most promising in the future for proccssing
small particles. Further, aluminum separation from the —10 mm fraction of electronic
scrap has been carried out using TNO ECS. It transpires that both the recovery and
the grade of the aluminum concentrate are superior to those obtained with the rotary
bolted‐drum ECS of any type.
Research and Commercialisation of Treatment of Fine Ilmenite With Slon Magnetic Separators
Authors: Da-He Xiong
Published: September 2007

The fine ilmenite material finer than 0.045mm at the Pang Zhi Hua Ilmenite Processing
Plant was discarded for the lack of efficient processing equipment and method. The total
recovery of ilmenite in the plant had been only about 17‐20%. To increase the ilmenite
recovery, numerous laboratory, pilot and commercial tests were conducted in 1995‐1996.
Finally, a magnetic separation‐flotation flowsheet was chosen for the commercial test, in
which the fine fraction was fed into 125 mm diameter cyclones for desliming. The underflow
of the cyclones was then fed into the magnetic separation‐flotation flowsheet. A SLon‐
1500 vertical ring and pulsating high gradient magnetic separator was applied as a rougher
and was followed by flotation as a cleaner. The overall results of the magnetic separationflotation
flowsheet in the commercial test were: feed 11.03% TiO2, concentrate 47.36%
TiO2, recovery 44.79% TiO2. The flowsheet of the commercial test has been used as a production process since 1997. The recovery accounted for about 12% TiO2 of the feed
into the ilmenite processing plant.
The Application of Magnetic Techniques in Biosciences
Authors: Safarikova M. , Safarik I.
Published: September 2007

The idea to use magnetic techniques in biosciences is not new, but it has enjoyed a resurgence
of interest especially during the last two decades. Magnetic adsorbents, carriers
and modifiers can be used for the immobilization, isolation, modification, detection,
determination and removal of a variety of biologically active compounds, xenobiotics,
cellular components and cells. Magnetic separation and labelling have recently found
many useful and interesting applications in various areas of biosciences, especially
in molecular and cell biology, microbiology, biochemistry and bioanalytical chemistry.
Special attention is being paid to the possible biomedical and clinical applications.
Currently, the magnetic selective separation, represents the most often used magnetic
technique. It can facilitate or accelerate many separation and purification processes
especially in heterogeneous systems. To perform a biomagnetic separation an appropriate
magnetic separator and magnetic particles or other magnetic labels are needed.
Several types of separators and a wide assortment of magnetic particles of different type
and size (usually surface modified) are commercially available. The importance of biomagnetic
(separation) techniques has increased in recent years and further development
of new important applications is expected in the future. The purpose of this review
is to summarise basic elements and prospects of biomagnetic techniques and to highlight
possible applications in various bioscience disciplines.
Comprehensive Analysis of PPARα-Dependent Regulation of Hepatic Lipid Metabolism by Expression Profiling
Authors: Rakhshandehroo Maryam , Sanderson Linda M. , Matilainen Merja , Stienstra Rinke , Carlberg Carsten , de Groot Philip J. , Müller Michael , Kersten Sander
Published: September 2007

PPARαis a ligand-activated transcription factor involved in the regulation of nutrient metabolism and inflammation. Although much is already known about the function of PPARαin hepatic lipid metabolism, many PPARα-dependent pathways and genes have yet to be discovered. In order to obtain an overview of PPARα-regulated genes relevant to lipid metabolism, and to probe for novel candidate PPARαtarget genes, livers from several animal studies in which PPARαwas activated and/or disabled were analyzed by Affymetrix GeneChips. Numerous novel PPARα-regulated genes relevant to lipid metabolism were identified. Out of this set of genes, eight genes were singled out for study of PPARα-dependent regulation in mouse liver and in mouse, rat, and human primary hepatocytes, including thioredoxin interacting protein (Txnip), electron-transferring-flavoproteinβpolypeptide (Etfb), electron-transferring-flavoprotein dehydrogenase (Etfdh), phosphatidylcholine transfer protein (Pctp), endothelial lipase (EL, Lipg), adipose triglyceride lipase (Pnpla2), hormone-sensitive lipase (HSL, Lipe), and monoglyceride lipase (Mgll). Using an in silico screening approach, one or more PPAR response elements (PPREs) were identified in each of these genes. Regulation of Pnpla2, Lipe, and Mgll, which are involved in triglyceride hydrolysis, was studied under conditions of elevated hepatic lipids. In wild-type mice fed a high fat diet, the decrease in hepatic lipids following treatment with the PPARαagonist Wy14643 was paralleled by significant up-regulation of Pnpla2, Lipe, and Mgll, suggesting that induction of triglyceride hydrolysis may contribute to the anti-steatotic role of PPARα. Our study illustrates the power of transcriptional profiling to uncover novel PPARα-regulated genes and pathways in liver.
A Hybrid Query Scheme to Speed Up Queries in Unstructured Peer-to-Peer Networks
Authors: Zhang Zhan , Tang Yong , Chen Shigang , Jian Ying
Published: September 2007

Unstructured peer-to-peer networks have gained a lot of popularity due to their resilience to network dynamics. The core operation in such networks is to efficiently locate resources. However, existing query schemes, for example, flooding, random walks, and interest-based shortcut suffer various problems in reducing communication overhead and in shortening response time. In this paper, we study the possible problems in the existing approaches and propose a new hybrid query scheme, which mixes inter-cluster queries and intracluster queries. Specifically, the proposed scheme works by efficiently locating the clusters, sharing similar interests with intercluster queries, and then exhaustively searching the nodes in the found clusters with intracluster queries. To facilitate the scheme, we propose a clustering algorithm to cluster nodes that share similar interests, and a labeling algorithm to explicitly capture the clusters in the underlying overlays. As demonstrated by extensive simulations, our new query scheme can improve the system performance significantly by achieving a better tradeoff among communication overhead, response time, and ability to locate more resources.
Waves Trapped by Submerged Obstacles at High Frequencies
Authors: Marín A. M. , Ortíz R. D. , Zhevandrov P.
Published: September 2007

As is well known, submerged horizontal cylinders can serve as waveguides for surface water waves. For large values of the wavenumberkin the direction of the cylinders, there is only one trapped wave. We construct asymptotics of these trapped modes and their frequencies ask→∞in the case of one or two submerged cylinders by means of reducing the initial problem to a system of integral equations on the boundaries and then solving them using a technique suggested by Zhevandrov and Merzon (2003).
Retailer's EOQ Model with Limited Storage Space Under Partially Permissible Delay in Payments
Authors: Huang Yung-Fu , Lai Chih-Sung , Shyu Maw-Liann
Published: September 2007

The main purpose of this paper wants to investigate the optimal retailer's lot-sizing policy with two warehouses under partially permissible delay in payments within the economic order quantity (EOQ) framework. In this paper, we want to extend that fully permissible delay in payments to the supplier would offer the retailer partially permissible delay in payments. That is, the retailer must make a partial payment to the supplier when the order is received. Then the retailer must pay off the remaining balance at the end of the permissible delay period. In addition, we want to add the assumption that the retailer's storage space is limited. That is, the retailer will rent the warehouse to store these exceeding items when the order quantity is larger than retailer's storage space. Under these conditions, we model the retailer's inventory system as a cost minimization problem to determine the retailer's optimal cycle time and optimal order quantity. Three theorems are developed to efficiently determine the optimal replenishment policy for the retailer. Finally, numerical examples are given to illustrate these theorems and obtained a lot of managerial insights.
Efficient TTI for 3G Multimedia Applications
Authors: Chaikalis Costas
Published: September 2007

Time transmission interval (TTI) or outer block interleaving is an important task for the implementation of UMTS turbo coding in flat Rayleigh fading environment. An efficient TTI choice can save computational complexity. However, different multimedia scenarios are investigated using the maximum UMTS frame length, and simulation results are presented for the four possible outer block interleaver configurations in the case of flat Rayleigh fading channel. It is shown that different operating environments require an appropriate TTI in terms of bit error rate (BER) performance for the following data rates: 28.8 kbps, 64 kbps, 144 kbps, 384 kbps, and 2 Mbps.
A Connection betweenC∞(𝕋n)and𝒮(ℝn)
Authors: Luo Guangzhou , Liu Peide
Published: September 2007

We interpretC∞(𝕋n)as a quotient space of𝒮(ℝn).
Thin-Film Solar Cells Based on the Polycrystalline Compound Semiconductors CIS and CdTe
Authors: Powalla Michael , Bonnet Dieter
Published: September 2007

Thin-film photovoltaic modules based on Cu-In-Ga-Se-S (CIS) and CdTe are already being produced with high-quality and solar conversion efficiencies of around 10%, with values up to
14% expected in the near future. The integrated interconnection of single cells into large-area
modules of 0.6×1.2m2 enables low-cost mass production, so that thin-film modules will soon be
able to compete with conventional silicon-wafer-based modules. This contribution provides an
overview of the basic technologies for CdTe and CIS modules, the research and development (R&D) issues,
production technology and capacities, the module performance in long-term outdoor testing, and their use
in installations.
Semiotic Mediation, Dialogue and the Construction of Knowledge
Authors: Wells Gordon
Published: September 2007

Both Vygotsky, a psychologist, and Halliday, a social linguist, argue for the central role of language in human development. Language is the principal mode of meaning making; it mediates both the communication through which thinking with others is made possible and also the inner speech through which individual thinking is brought under conscious control. I develop this central claim by drawing on the writings of Vygotsky and Bakhtin, as well as those of their colleagues and followers to argue for the importance of encouraging dialogue in all educational settings in order to enable learners of all ages to construct knowledge together, and thereby to enhance their individual understanding of the world and their potential for action in it.
Neuromuscular Implications in CADASIL
Authors: Finsterer Josef
Published: September 2007

Objectives: Recent studies indicate that Notch3 gene mutations not only manifest as cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) but also in the peripheral nerves and skeletal muscles. Methods: A MEDLINE search with appropriate terms was carried out. Six articles, dealing with neuromuscular involvement in CADASIL, were selected and reviewed. Results: Several case studies presented CADASIL patients with clinical features of myopathy. Neurological diagnostic workup in these patients revealed weakness, wasting, reduced/exaggerated tendon reflexes, abnormal nerve conduction and electromyography, muscle biopsy with ragged red muscle fibers, reduced COX staining, decreased complex I respiratory chain activity, abnormally structured mitochondria, or mitochondrial DNA (mtDNA) mutations, such as G5650A in the tRNAAla gene, or various other mtDNA substitutions. Additionally, fibroblasts in skin biopsy may show reduced complex V respiratory chain activity. Conclusions: These findings suggest Notch3 mutations to be associated with mitochondrial disease, particularly affecting the skeletal muscle. Whether mtDNA mutations were induced by Notch3 mutations, by oxidative stress due to chronic hypoxia, resulting from arteriopathy, or occurred spontaneously remains elusive. Patients carrying Notch3 mutations should be systematically investigated for neuromuscular involvement, which may have therapeutic and prognostic implications for these patients.
C-Reactive Protein and Fibrinogen in Acute Stroke Patients with and without Sleep Apnea
Authors: Dziewas Rainer , Ritter Martin , Krüger Linn , Berger Stefanie , Langer Claus , Kraus Jörg , Dittrich Ralf , Schäbitz Wolf R. , Ringelstein E. Bernd , Young Peter
Published: September 2007

Background and Purpose: Although sleep apnea (SA) is a risk factor for ischemic stroke and an important prognosticator in affected patients, the exact pathophysiological link between SA and stroke remains to be established. We investigated whether levels of C-reactive protein (CRP) and fibrinogen are increased in patients with acute stroke and SA compared with stroke patients without SA. Patients and Methods: 117 consecutive patients with ischemic stroke admitted to our stroke unit within 12 h after stroke onset were included in this study. On admission, CRP and fibrinogen levels were determined. All patients received cardiorespiratory polygraphy during the first 72 h of their hospital stay. In all patients, demographic data, National Institutes of Health Stroke Scale score and cerebrovascular risk factors were assessed. Results: SA defined by an apnea-hypopnea index (AHI) of ≧10/h was found in 64 (55%) patients. Elevated CRP and fibrinogen levels were seen twice as often in patients with SA than in patients without (CRP: 52 vs. 26%; fibrinogen: 72 vs. 37%). After multivariate logistic regression analysis, an AHI of ≧10/h was independently correlated with raised levels of both of these parameters. Conclusion: SA is independently associated with raised levels of CRP and fibrinogen in patients with acute ischemic stroke. We assume that both proteins are part of the pathophysiological pathway linking SA to stroke.
Polymorphisms at the Osteoprotegerin and Interleukin-6 Genes in Relation to First-Ever Stroke
Authors: Strand Magnus , Söderström Ingegerd , Wiklund Per-Gunnar , Hallmans Göran , Weinehall Lars , Söderberg Stefan , Olsson Tommy
Published: September 2007

Background: Arterial calcification and osteoporosis often coexist, especially in postmenopausal women. Osteoporosis associates with a substantially increased risk of stroke in elderly women, suggesting that impaired estrogen signaling may link stroke and osteoporosis. Osteoprotegerin (OPG, TNFRSF11B) and interleukin-6 (IL-6, IL6) are putative target genes for estrogen signaling and have been implicated in both cardiovascular diseases and osteoporosis. We hypothesized that specific polymorphisms in these genes may be associated with increased risk of ischemic stroke or intracerebral hemorrhage (ICH). Methods: We performed a population-based prospective nested case-control study, in which the relationships between polymorphisms (OPG-1181G/C, OPG-950T/C and IL6-174G/C) and ischemic stroke and ICH were examined. Definitive first-ever stroke events (n = 388), i.e. ischemic stroke (n = 320), ICH (n = 61) and unspecified stroke (n = 7) cases, and controls without cardiovascular disease (n = 773), matched for age, sex and geographical region were studied. Univariate and multivariate models using conditional logistic regression, which included traditional risk factors, were used to test for association. Results: Carriers of the OPG-1181C/C genotype had a significantly (p = 0.018) increased risk of ICH (OR, 2.69; 95% CI, 1.19–6.12) in the univariate analysis. After adjustments (hypertension, diabetes, BMI and triglycerides), this genotype remained significantly (p = 0.005) associated with ICH (OR, 6.04; 95% CI, 1.71–21.29). By contrast, no correlations were found between this genotype and ischemic stroke, nor between the OPG-950T/C or IL6-174G/C polymorphisms and stroke subtypes. Conclusions: In this population, the OPG-1181C/C genotype associates with first-ever ICH, implying that alterations in OPG-mediated signaling in the vasculature may be involved in the pathophysiology of this disease.