28 research outputs found
Проблема взаємодії влади і суспільства в сучасних вітчизняних наукових дослідженнях
Проаналізовано
стан дослідження
проблеми
взаємодії влади
і суспільства сучасними
вітчизняними
науковцями.
Зроблено
висновок,
що проблема
взаємодії влади
і
суспільства є предметом
сучасних
міждисциплінарних
досліджень насамперед
таких
галузей
як політичні науки
та державне
управління,
у межах
яких науковці
розглядають
цю проблему
крізь призму
комунікативної
діяльності
органів
державної
влади,
їх
взаємодії зі ЗМІ та інститутами
громадянського
суспільства.Проанализоровано
состояние
исследования
проблемы
взаимодействия
власти
и
общества
в современной
украинской
науке.
Сделан
вывод
о том, что проблема
взаимодействия
власти
и общества
является
предметом
междисциплинарных
исследований
в первую
очередь
таких
областей,
как политические
науки
и государственное
управление,
в которых
учёные
рассматривают
эту проблему
через
призму
коммуникативной
деятельности
органов
власти,
их взаимодействия
со СМИ и институтами
гражданского
общества.The article demonstrates communication activity of governmental authority as an interdisciplinary
political and public administration studies object. Communication as a professional
activity problem, role of media as a mediator between the state and the society, political
leadership and political communication mechanism, specifics of the development of authorities
objects in Ukraine all are in view of the Ukrainian researchers. But the communication of
the President of Ukraine is still does not get attention it deserves
Performance of Tablet Splitters, Crushers, and Grinders in Relation to Personalised Medication with Tablets
Swallowing problems and the required dose adaptations needed to obtain optimal pharmacotherapy may be a hurdle in the use of tablets in daily clinical practice. Tablet splitting, crushing, or grinding is often applied to personalise medication, especially for the elderly and children. In this study, the performance of different types of (commercially available) devices was studied. Included were splitters, screwcap crushers, manual grinders, and electric grinders. Unscored tablets without active ingredient were prepared, with a diameter of 9 and 13 mm and a hardness of 100–220 N. Tablets were split into two parts and the difference in weight was measured. The time needed to pulverise the tablets (crush time) was recorded. The residue remaining in the device (loss) was measured. The powder was sieved to obtain a particle fraction >600 µm and <600 µm. The median particle size and particle size distribution of the later fraction were determined using laser diffraction analysis. Splitting tablets into two equal parts appeared to be difficult with the devices tested. Most screwcap grinders yielded a coarse powder containing larger chunks. Manual and especially electric grinders produced a finer powder, making it suitable for administration via an enteral feeding tube as well as for use in individualised preparations such as capsules. In conclusion, for domestic and incidental use, a screwcap crusher may provide sufficient size reduction, while for the more demanding regular use in hospitals and nursing residences, a manual or electric grinder is preferred
Colloidal Mineral Liquid Crystals. Formation & Manipulation
The central topic of this thesis is the formation, manipulation and characterization of colloidal mineral liquid crystals. Liquid crystals are liquids containing ordered anisometric particles. A range of liquid crystalline phases exists, from solely orientationally ordered nematic phases to orientationally and 1D or 2D positionally ordered smectic and columnar phases. Liquid crystals have several applications but are mostly known for their application in LCD’s: Liquid Crystal Displays, which contain a nematic liquid crystal. Colloidal liquid crystals generally form spontaneously. For potential applications however, it is important to be able to controllably form and tune the desired liquid crystal phase. The key feature of the research described in this thesis is therefore how the formation of these liquid crystals can be manipulated. This thesis is split in two parts. Part I describes the mineral goethite, which consists of board-like colloids. Various methods to influence the liquid crystal phase behaviour are described. These include the earth gravitational field, a depletant and an external magnetic field. It is described how letting the colloids slowly sediment in the earth gravitational field solves the particle polydispersity problem. The nematic phase for example, was found to absorb particles that do not fit in the smectic phase. Additionally, observations of fractionated crystallization in both the smectic and the columnar phase are discussed. Another approach to influence the phase behaviour is by changing the inter-particle interactions by introducing a spherical depletant into the suspension. This thesis describes how the depletant-induced attraction between the particles promotes the formation of the rare biaxial (in which particles are orientationally ordered in three dimensions) smectic phase. The final method studied is an external magnetic field. We describe how the magnetic field can induce phase transitions between the three different nematic phases (biaxial, prolate and oblate uniaxial), depending on the particle aspect ratios. Additionally it is described how a magnetic field was used to reorient the goethite columnar phase and to study its reorientation pathway with synchrotron small angle X-ray scattering, revealing nanoshear between layers of particles. In Part II of this thesis the mineral gibbsite, consisting of plate-like colloids, is described. Although liquid crystals are generally studied with scattering techniques, in Part II we focus on direct space imaging of the liquid crystals with confocal laser scanning microscopy. This technique enables characterization of the liquid crystals in real-space and time at the particle level. This requires large and fluorescent particles. Different general synthesis methods to prepare such platelets are described. Additionally, results of a preliminary confocal study are discussed, which reveals the observation of single particles as well as their liquid crystalline phase. Since liquid crystals of larger particles are more challenging for X-ray scattering studies, a 3D X-ray scattering method is described which helps make unambiguous identification of the liquid crystal phase
Colloidal Mineral Liquid Crystals. Formation & Manipulation
The central topic of this thesis is the formation, manipulation and characterization of colloidal mineral liquid crystals. Liquid crystals are liquids containing ordered anisometric particles. A range of liquid crystalline phases exists, from solely orientationally ordered nematic phases to orientationally and 1D or 2D positionally ordered smectic and columnar phases. Liquid crystals have several applications but are mostly known for their application in LCD’s: Liquid Crystal Displays, which contain a nematic liquid crystal. Colloidal liquid crystals generally form spontaneously. For potential applications however, it is important to be able to controllably form and tune the desired liquid crystal phase. The key feature of the research described in this thesis is therefore how the formation of these liquid crystals can be manipulated. This thesis is split in two parts. Part I describes the mineral goethite, which consists of board-like colloids. Various methods to influence the liquid crystal phase behaviour are described. These include the earth gravitational field, a depletant and an external magnetic field. It is described how letting the colloids slowly sediment in the earth gravitational field solves the particle polydispersity problem. The nematic phase for example, was found to absorb particles that do not fit in the smectic phase. Additionally, observations of fractionated crystallization in both the smectic and the columnar phase are discussed. Another approach to influence the phase behaviour is by changing the inter-particle interactions by introducing a spherical depletant into the suspension. This thesis describes how the depletant-induced attraction between the particles promotes the formation of the rare biaxial (in which particles are orientationally ordered in three dimensions) smectic phase. The final method studied is an external magnetic field. We describe how the magnetic field can induce phase transitions between the three different nematic phases (biaxial, prolate and oblate uniaxial), depending on the particle aspect ratios. Additionally it is described how a magnetic field was used to reorient the goethite columnar phase and to study its reorientation pathway with synchrotron small angle X-ray scattering, revealing nanoshear between layers of particles. In Part II of this thesis the mineral gibbsite, consisting of plate-like colloids, is described. Although liquid crystals are generally studied with scattering techniques, in Part II we focus on direct space imaging of the liquid crystals with confocal laser scanning microscopy. This technique enables characterization of the liquid crystals in real-space and time at the particle level. This requires large and fluorescent particles. Different general synthesis methods to prepare such platelets are described. Additionally, results of a preliminary confocal study are discussed, which reveals the observation of single particles as well as their liquid crystalline phase. Since liquid crystals of larger particles are more challenging for X-ray scattering studies, a 3D X-ray scattering method is described which helps make unambiguous identification of the liquid crystal phase
Phase behaviour of lyotropic liquid crystals in external fields and confinement
This mini-review discusses the influence of external fields on the phase behaviour of lyotropic colloidal liquid crystals. The liquid crystal phases reviewed, formed in suspensions of highly anisotropic particles ranging from rod- to board- to plate-like particles, include nematic, smectic and columnar phases. The external fields considered are the earth gravitational field and electric and magnetic fields. For electric and magnetic fields single particle alignment, collective reorientation behaviour of ordered phases and field-induced liquid crystal phase transitions are discussed. Additionally, liquid crystal phase behaviour in various confining geometries, e.g. slit-pore, circular and spherical confinement will be reviewed
A certainty-based approach for dynamic hierarchical classification of product order satisfaction
E-commerce companies collaborate with retailers to sell products via their platforms, making it increasingly important to preserve platform quality. In this paper, we contribute by introducing a novel method to predict the quality of product orders shortly after they are placed. By doing so, platforms can act fast to resolve bad quality orders and potentially prevent them from happening. This introduces a trade-off between accuracy and timeliness, as the sooner we predict, the less we know about the status of a product order and, hence, the lower the reliability. To deal with this, we introduce the Hierarchical Classification Over Time (HCOT) algorithm, which dynamically classifies product orders using top-down, non-mandatory leaf-node prediction. We enforce a blocking approach by proposing the Certainty-based Automated Thresholds (CAT) algorithm, which automatically computes optimal thresholds at each node. The resulting CAT-HCOT algorithm has the ability to provide both accurate and timely predictions by classifying a product order's quality on a daily basis if the classification reaches a predefined certainty. CAT-HCOT obtains a predictive accuracy of 94%. Furthermore, CAT-HCOT classifies 40% of product orders on the order date itself, 80% within five days after the order date, and 100% of product orders after 10 days.</p
A certainty-based approach for dynamic hierarchical classification of product order satisfaction
E-commerce companies collaborate with retailers to sell products via their platforms, making it increasingly important to preserve platform quality. In this paper, we contribute by introducing a novel method to predict the quality of product orders shortly after they are placed. By doing so, platforms can act fast to resolve bad quality orders and potentially prevent them from happening. This introduces a trade-off between accuracy and timeliness, as the sooner we predict, the less we know about the status of a product order and, hence, the lower the reliability. To deal with this, we introduce the Hierarchical Classification Over Time (HCOT) algorithm, which dynamically classifies product orders using top-down, non-mandatory leaf-node prediction. We enforce a blocking approach by proposing the Certainty-based Automated Thresholds (CAT) algorithm, which automatically computes optimal thresholds at each node. The resulting CAT-HCOT algorithm has the ability to provide both accurate and timely predictions by classifying a product order's quality on a daily basis if the classification reaches a predefined certainty. CAT-HCOT obtains a predictive accuracy of 94%. Furthermore, CAT-HCOT classifies 40% of product orders on the order date itself, 80% within five days after the order date, and 100% of product orders after 10 days.</p
3D structure of nematic and columnar phases of hard colloidal platelets
We present small angle x-ray scattering data of single-domain nematic and columnar liquid crystal phases in suspensions of sterically stabilized gibbsite platelets. The measurements are performed with different sample orientations to obtain information about the three-dimensional structure of the liquid crystalline phases. With the x-ray beam incident along the director of the nematic phase a strong correlation peak is observed corresponding to the side-to-side interparticle correlations, which suggests a columnar nematic structure. Upon sample rotation this side-to-side correlation peak of the nematic shifts to higher Q-values, suggesting the presence of strong fluctuations of small stacks of particles with different orientations, while the overall particle orientation is constant. In the hexagonal columnar phase, clear Bragg intercolumnar reflections are observed. Upon rotation, the Q-value of these reflections remains constant while their intensity monotonically decreases upon rotation. This indicates that the column orientation fluctuates together with the particle director in the columnar phase. This difference between the behaviour of the columnar and the nematic reflections upon sample rotation is used to assign the liquid crystal phase of a suspension consisting of larger platelets, where identification can be ambiguous due to resolution limitations