Naturalness arguments for weak-scale supersymmetry favour supersymmetric partners of the third generation quarks with masses not too far from those of their Standard Model counterparts. If the masses ...of top and bottom squarks are below 1 TeV, the direct pair production cross-section is sufficient to produce observable signatures at the ATLAS detector and to probe various theoretical scenarios with the Large Hadron Collider (LHC) data at √s = 8 TeV. The most recent ATLAS results from searches for direct stop and sbottom pair production are presented in these proceedings. No evidence of deviations from the Standard Model expectation has been observed, and the limits have been set on the masses of the top and bottom squarks.
Abstract
Layered phyllosilicate fillers have received attention in the polymer industry due to their unique nanoscale sheet-like structure. Adding a small amount of bentonite nanofiller gives rise to ...improved mechanical, thermal, and gas barrier properties of rubber mixtures. Depending on the application, natural bentonite is often modified by physical processes or by chemical processes (intercalation, cation exchange process, functionalization, pillaring, etc.). Chemical modification increases the size of the interlayer spaces and provides a hydrophobic environment. Functionalization (e.g., silanization), which encompasses the chemical grafting of thermally stable silane coupling agents onto the clay platelets, make inorganic bentonite and the organic polymer matrix compatible. In the introduced study, commercial bentonite P130 from Lieskovec deposit was modified by silane (3-aminopropyl trietoxysilane) treatment. Different techniques such as infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were used to characterize modified and raw bentonite sample. Silanized P130s and raw product P130 were added to the natural rubber matrix to examine the influence of chemically functionalized bentonite on curing characteristic (
M
H
,
M
L
,
t
s2
,
t
90
, Δ
M
) and mechanical properties (TS
b
, E
b
, hardness) of rubber vulcanizates. Organo-bentonite was mixed into a rubber blend in particular ratio of 5, 10, 15, 20 phr in various combination with silane (3-aminopropyl triethoxysilane), Perkasil and carbon black. The highest maximum torque values were obtained with the sample using 20 phr of silanized P130s. The tensile strength (TS
b
) values decreased with increasing P130 content, as well as non-silanized and silanized P130. However, when 20 phr P130s was used, value of TS
b
was higher. The most enhanced properties of rubber blends were found with the addition of 20 phr of silanized bentonite P130s.
From the aspect of the modern approach, it is necessary to increase the intercalation efficiency for the objective of widespread market application of kaolinite. The submitted article deals with the ...microwave-assisted modification of kaolinite (Kaol). Using potassium acetate (KAc) solution and dimethyl sulphoxide (DMSO), Kaol was treated chemically by a microwave radiation at different time intervals at a set constant temperature. Different techniques, such as X-ray diffraction patterns analysis (XRD), Fourier transformed infrared spectroscopy (FT-IR) spectroscopy, thermogravimetry/ differential scanning calorimetry (TG/DSC), and scanning electron microscopy (SEM) were used to characterize Kaol and modified kaolinite samples. The modification was observed after microwave radiation was applied for a short time (30 min). Finally, for the supplementation of the results, the model rubber compounds, filled with Kaol, modified Kaol-KAc and Kaol-DMSO samples in the amount of 10 phr (parts per hundred rubber), were prepared. The effect of modified kaolinite on the curing characteristics and mechanical properties in sulphur-cured natural rubber (NR) compounds was investigated. Partial substitution of carbon black with Kaol-DMSO led to the lower minimum torque and the acceleration of the crosslinking reaction. Moreover, the NR vulcanizates containing Kaol-DMSO showed higher tensile strength and hardness along with high maximum torque that are indicators of the reinforcing effect of the modified kaolinite.
•Kaolinite modified by chemical treatment using microwave irradiation.•Dimethyl sulphoxide and potassium acetate were used for the modification.•Significant shortening of the time needed for modification.•Preparation of the rubber composites with organo-kaolinites.•Improvement of curing and mechanical properties of rubber composite materials.
The diffuse coplanar surface barrier plasma discharge (DCSBD) still belongs to specific methods of modifying (activating) the surface of polymeric materials. The present work deals with surface ...treatment of polypropylene foils by plasma discharge, investigation and subsequent identification of changes caused by mentioned discharge. The modified surface was examined by measuring the wetting angle. Film surface morphology and topography was investigated by scanning electron microscope (SEM) and atomic force microscopy (AFM), respectively. Subsequently, it was examined whether the modification of polypropylene by DCSBD plasma discharge only affects the surface of the investigated material or also changes structural properties in studied material, based on the obtained data from DMA analysis.
Denitrification of low concentrations of NO
3–N (20
mg
L
−1), with methanol as an organic carbon source (COD:NO
3–N
=
6) in laboratory upflow sludge bed reactor (USB), was tested as a possibility for ...wastewater post-treatment. By gradual increase of volumetric loading (Bv) and hydraulic loading (
γ), anoxic biomass spontaneously granulated out even from flocculate activated sludge and from anaerobic granulated sludge as well. Anaerobic granulated biomass derived from high-rate anaerobic IC reactor was a far better inoculum for anoxic granulation and for denitrification in the USB reactor. The maximum level of Bv and
γ was remarkably higher with the use of anaerobic granulated inoculum, (19–22
kg COD
m
−3
d
−1; 3.2–3.7
kg NO
3–N
m
−3
d
−1; 2.8–3.2
m
3
m
−2
h
−1; SVI
=
15
mL
g
−1) in comparison to inoculum from flocculate activated sludge (4.2–8.1
kg COD
m
−3
d
−1; 0.7–1.4
kg NO
3–N
m
−3
d
−1; 0.7–1.15
m
3
m
−2
h
−1; SVI
=
40–95
mL
g
−1).
The sol–gel method was used for preparation of TiO2 sols without and with the addition of “small molecules” — acetylacetone and acetic acid. The TiO2 films were made by dip-coating method in ...different time intervals after preparation of sols. Properties of film surface, such as morphology, rms-roughness and adhesion force were studied using atomic force microscopy (AFM). The contact angle of water and diiodomethane was measured for identification of polar and dispersion component of the surface free energy (SFE). From the obtained results, it can be seen that “small molecules” influence the morphology of films. During the first days after the sol preparation, there is the increase of roughness of films prepared from sols with “small molecules” but with the increasing time, the roughness decreases. There is no crystallization of films with acetylacetone. For films prepared from sols with acetylacetone, the polar component of SFE is lower than in the case of films prepared from sols without “small molecules” and with acetic acid. The “small molecules” decrease the stiffness and adhesion force mainly for films prepared several days after sol preparation. This influence is the result of complex effect of “small molecules” on processes occurring during preparation of films, from hydrolysis reaction over process of particle growth to thermal treatment.
•Addition of “small molecules” influences surface properties of prepared TiO2 films.•Addition of “small molecules” decreases of adhesion force, stiffness and roughness.•“Small molecules” increase dispersion component and decreases polar component of SFE.•Influence of acetylacetone and acetic acid is result of their complex effect.•During film formation, hydrolysis, particle growth, thermal treatment are influenced.
Myelodysplastic syndromes (MDS) represent a clinically and genetically heterogeneous group of clonal haematopoietic diseases characterized by a short survival and high rate of transformation to acute ...myeloid leukaemia (AML). In spite of this variability, MDS is associated with typical recurrent non-random cytogenetic defects. Chromosomal abnormalities are detected in the malignant bone-marrow cells of approximately 40-80 % of patients with primary or secondary MDS. The most frequent chromosomal rearrangements involve chromosomes 5, 7 and 8. MDS often shows presence of unbalanced chromosomal changes, especially large deletions del(5), del(7q), del(12p), del(18q), del(20q) or losses of whole chromosomes (7 and Y). The most typical cytogenetic abnormality is a partial or complete deletion of 5q- that occurs in roughly 30 % of all MDS cases either as the sole abnormality or in combination with other aberrations as a part of frequently complex karyotypes. The mechanisms responsible for the formation of MDS-associated recurrent translocations and complex karyotypes are unknown. Since some of the mentioned aberrations are characteristic for several haematological malignancies, more general cellular conditions could be expected to play a role. In this article, we introduce the most common rearrangements linked to MDS and discuss the potential role of the non-random higher-order chromatin structure in their formation. A contribution of the chromothripsis - a catastrophic event discovered only recently - is considered to explain how complex karyotypes may occur (during a single event).
Crystallization kinetics of Al2O3–Yb2O3 glasses PLSKO, Alfonz; LISKA, Marek; PAGACOVA, Jana
Journal of thermal analysis and calorimetry,
2012/5, Letnik:
108, Številka:
2
Journal Article, Conference Proceeding
Recenzirano
Crystallization kinetics of Al
2
O
3
–Yb
2
O
3
glass microspheres with two different compositions was studied by DTA. Heating rates ranging from 3 to 15 °C min
−1
were used for DTA measurement. The ...DTA curves obtained were transformed into the dependence of conversion, α, on temperature. The model
f
(α) = α
n
(1 − α)
m
, i.e., the model of Sestak and Berggren, was found suitable for the description of crystallization kinetics. The best fit of experimental data was obtained if the full set of measured conversion degrees was used for calculation of kinetic parameters. In this manner, the following results were obtained:
A
= 6.10 × 10
20
min
−1
,
E
= 4.68 × 10
5
J mol
−1
,
n
= 0.634,
m
= 1.037 for 30 wt% Al
2
O
3
–70 wt% Yb
2
O
3
glass, and
A
= 6.98 × 10
25
min
−1
,
E
= 5.97 × 10
5
J mol
−1
,
n
= 0.562,
m
= 0.975 for 45 wt% Al
2
O
3
–55 wt% Yb
2
O
3
glass.
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