Particle Engineering: Fundamentals of Particle Formation and Crystal Growth

MRS Bulletin ◽  
2006 ◽  
Vol 31 (11) ◽  
pp. 881-886 ◽  
Author(s):  
Alfred Y. Lee ◽  
Allan S. Myerson
Keyword(s):  
Crystal Growth ◽  
Dosage Form ◽  
Decisive Role ◽  
Product Performance ◽  
Particle Engineering ◽  
Particle Properties ◽  
Packing Arrangement ◽  
Form Development

AbstractThe engineering of particles with customized properties optimized for dosage form manufacture (tablet, capsule, ointment, etc.) has long been a goal of the pharmaceutical industry. Particles can be designed through modification in the size, morphology, and packing arrangement of the solids. The most common approach in achieving this is through crystallization. In this bottom-up process, the two main steps, nucleation and crystal growth, both play a decisive role in shaping the quality of the final crystalline product. In this review, the role of nucleation and crystal growth in controlling particle properties is discussed, and examples are provided that demonstrate the variation in solid-state properties as a function of size, habit (morphology), and internal structure of the particles. In addition, the role of particle properties in product performance and dosage form development of pharmaceuticals is also discussed.

Role of Internal Radiation With or Without Melt Inclusions During Czochralski Sapphire Crystal Growth

2013 ◽  
Author(s):  
H. S. Fang ◽  
Q. J. Zhang ◽  
L. L. Zheng ◽  
M. J. Zhang ◽  
J. Tian
Keyword(s):  
Crystal Growth ◽  
Melt Inclusions ◽  
Light Emitting Diode ◽  
Coupled Model ◽  
Discrete Ordinates ◽  
Sapphire Crystal ◽  
Interface Shape ◽  
Internal Radiation

Sapphire is the most popular substrate material for GaN thin-film crystal growth during the Light-emitting diode (LED) fabrication. The performance of GaN films is directly influenced by the quality of the substrates. The control of the growth front, i.e., solid /liquid interface, is critical to improve the quality of the sapphire. As a semi-transparent material, sapphire has an intermediate optical thickness, which requires considering of internal radiation for an accurate prediction of temperature field and interface shape. In the paper, a coupled model has been applied on the modeling of transport phenomena during the Czochralski (Cz) sapphire growth. Especially, the role of the internal radiation with or without melt inclusions has been examined carefully by Discrete Ordinates (DO) method. The interface convexity is influenced by the parameters of the models as well as by the melt inclusions. By setting the different optical properties at the inclusion regions, as observed in the experiments, the entrapment of gas or solid inclusions inside the crystal and its effect on the interface shape are examined.

Crystal Engineering: Upcoming Paradigm for Efficacious Pulmonary Drug Delivery

2018 ◽  
Vol 24 (21) ◽  
pp. 2438-2455 ◽  
Author(s):  
Preshita P. Desai ◽  
Sanyat S. Mapara ◽  
Vandana B. Patravale
Keyword(s):  
Drug Delivery ◽  
Crystal Engineering ◽  
Pulmonary Delivery ◽  
Delivery Systems ◽  
Pulmonary Drug Delivery ◽  
Particle Engineering ◽  
Particle Properties ◽  
Drug Deposition ◽  
Systemic Drug Delivery

Background and objective: Pulmonary drug delivery has transformed over a past few decades from being a platform for local pulmonary disease treatment to systemic drug delivery opportunities. In case of pulmonary delivery systems, particle properties are critical as they affect inhalation efficacy, pulmonary deposition, drug delivery and overall performance. With this in view, particle engineering has emerged as an advanced science that helps in designing of efficacious pulmonary delivery systems. Among various particle engineering branches, crystal engineering is being extensively explored as it provides an opportunity to optimize particles at morphological, physicochemical and molecular levels which are essential to understand the role of crystal engineering in pulmonary drug delivery. Methods: A thorough literature survey in the field of crystal engineering approaches explored for pulmonary drug delivery was conducted and the collected data was meticulously studied and summarized. Results: In the review, pulmonary system is discussed with respect to various sites for drug deposition in respiratory tract, mechanism of drug deposition and clearance. Further, critical crystal parameters are discussed in-depth and various crystal engineering methods are summarized with emphasis on their impact on pulmonary delivery. Also, inhalation devices are overviewed to understand their performance in relation to crystal based pulmonary formulations. Conclusion: The review enabled a detailed insight on crystal engineering approaches for design of pulmonary delivery systems.

scholarly journals Saccadic Suppression of Displacement Does Not Reflect a Saccade-Specific Bias to Assume Stability

Vision ◽  
2019 ◽  
Vol 3 (4) ◽  
pp. 49
Author(s):  
Sabine Born
Keyword(s):  
Visual Target ◽  
Target Position ◽  
Decisive Role ◽  
Saccadic Suppression ◽  
General Stability ◽  
Steady Fixation ◽  
Continuous Scale ◽  
Improved Performance

Across saccades, small displacements of a visual target are harder to detect and their directions more difficult to discriminate than during steady fixation. Prominent theories of this effect, known as saccadic suppression of displacement, propose that it is due to a bias to assume object stability across saccades. Recent studies comparing the saccadic effect to masking effects suggest that suppression of displacement is not saccade-specific. Further evidence for this account is presented from two experiments where participants judged the size of displacements on a continuous scale in saccade and mask conditions, with and without blanking. Saccades and masks both reduced the proportion of correctly perceived displacements and increased the proportion of missed displacements. Blanking improved performance in both conditions by reducing the proportion of missed displacements. Thus, if suppression of displacement reflects a bias for stability, it is not a saccade-specific bias, but a more general stability assumption revealed under conditions of impoverished vision. Specifically, I discuss the potentially decisive role of motion or other transient signals for displacement perception. Without transients or motion, the quality of relative position signals is poor, and saccadic and mask-induced suppression of displacement reflects performance when the decision has to be made on these signals alone. Blanking may improve those position signals by providing a transient onset or a longer time to encode the pre-saccadic target position.

scholarly journals INTELLECTUAL CAPITAL OF THE ORGANIZATION: ITS CONCEPT AND ESSENCE

2018 ◽  
pp. 38-43
Author(s):  
E. B. Ermishina ◽  
E. V. Orel
Keyword(s):  
Human Capital ◽  
Intellectual Capital ◽  
Scientific Revolution ◽  
Adam Smith ◽  
Decisive Role ◽  
John Stuart Mill ◽  
Social Progress ◽  
Ability To Work

The concept of human capital was introduced by Adam Smith and John Stuart Mill, who understood the quantity and quality of a person’s ability to work under him. In the scientific revolution this concept was introduced by D. Gilbert in the late 60’s. XX century. The theory of intellectual capital was further developed on the basis of the development of the theory of human capital. The article deals with modern concepts of human capital, which became the basis for substantiating the decisive role of a person, his abilities and potential in creating the value of a concrete organization and social progress. Much attention is paid to the structure of intellectual capital, which is represented by a combination of human, organizational and consumer capital; comparison of intellectual capital with physical is given.

Territorial Organization of Social Services in Central Russia: Shaping Features and Growth Drivers

10.12737/5224 ◽  
2014 ◽  
Vol 2 (3) ◽  
pp. 22-32 ◽  
Author(s):  
Бельчук ◽  
YElyena Byelchuk ◽  
Мариен ◽  
Lyudmila Mariyen
Keyword(s):  
Social Services ◽  
Spatial Organization ◽  
Life Quality ◽  
Decisive Role ◽  
Economic Activities ◽  
Economic Sectors ◽  
Central Russia ◽  
Territorial Organization

The paper considers several issues concerning spatial organization and development of social services at both macro- and meso-levels; reveals how various social services branches affect economic activities of territories of differing ranks, which plays a decisive role in human resources reproduction and helps to improve life quality of people, involved directly in shaping human capital of the society. The role of Central Russia and its constituent regions in shaping and running the national social services system is highlighted; drivers of social services territorial organization at the national state nucleus are examined. Also the author defines directions for further development of social services at the macro-region level, conducive to improving performance within all economic sectors.

Cognitive Health Counseling 40+

2013 ◽  
Vol 21 (1) ◽  
pp. 24-33 ◽  
Author(s):  
Anne Eschen ◽  
Franzisca Zehnder ◽  
Mike Martin
Keyword(s):  
Outcome Variable ◽  
Pilot Phase ◽  
Subjective Memory ◽  
Cognitive Health ◽  
Health Counseling ◽  
Agents Of Change ◽  
Main Outcome Variable ◽  
Further Development

This article introduces Cognitive Health Counseling 40+ (CH.CO40+), an individualized intervention that is conceptually based on the orchestration model of quality-of-life management ( Martin & Kliegel, 2010 ) and aims at improving satisfaction with cognitive health in adults aged 40 years and older. We describe the theoretically deduced characteristics of CH.CO40+, its target group, its multifactorial nature, its individualization, the application of subjective and objective measures, the role of participants as agents of change, and the rationale for choosing participants’ satisfaction with their cognitive health as main outcome variable. A pilot phase with 15 middle-aged and six older adults suggests that CH.CO40+ attracts, and may be particularly suitable for, subjective memory complainers. Implications of the pilot data for the further development of the intervention are discussed.

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