scholarly journals Chemically-induced controlled growth of CsPbBr3 perovskite nanocrystals

2017 ◽  
Author(s):  
◽  
Mariia Goriacheva
Keyword(s):  
Emission Spectra ◽  
Three Dimensions ◽  
Chemical Route ◽  
Visible Absorption ◽  
Continuous Irradiation ◽  
Perovskite Nanocrystals ◽  
New Class ◽  
Chemically Induced ◽  
Nanoscale Semiconductors

Trihalide perovskite nanocrystals have recently emerged as a new class of superior nanoscale semiconductors due to their outstanding optoelectronic properties. A family of all-inorganic CsPbX3 (X=Cl, Br, and I) perovskite nanocrystals is of a particular interest, due to its higher resistance to moisture, heat, and continuous irradiation. In this thesis work a novel chemical route was designed and studied for inducing the growth of CsPbBr3 perovskite nanocrystals at room temperature by intentional depletion of stabilizing ligands, leading to the nanocrystals' fusion. The growth of nanocrystals was achieved from 8 nm to 35 nm in average lateral dimensions, while preserving their optical and colloidal integrity. The thickness was found to be approx. 14 nm. Both UV-visible absorption and photoluminescence emission spectra indicated a red shift in the grown nanocrystals, compared to that of as-synthesized 8 nm nanocrystals. It was determined that the growth of NCs happened in all three dimensions, supporting the theory of induced fusion. The discovered chemical route for triggering post-synthetic growth of as-synthesized perovskite nanocrystals offered a new perception on understanding the role of stabilizing surfactants on the surface of perovskite nanocrystals. It was shown experimentally that the ligands not only participated in colloidal stabilization and photoluminescence enhancement, but also could be efficiently employed for post-synthetic manipulation of nanocrystals' size, band gap and shape.

Practical consensus recommendations - Current role of immune response evaluation criteria in solid tumors criteria in the management of cancer patients receiving immunotherapy

2019 ◽  
Vol 4 ◽  
pp. 21-23
Author(s):  
Purvish M. Parikh ◽  
T. P. Sahoo ◽  
Randeep Singh ◽  
Bahl Ankur ◽  
Talvar Vineet ◽  
...  
Keyword(s):  
Immune Response ◽  
Solid Tumors ◽  
Evaluation Criteria ◽  
Supporting Evidence ◽  
Response Evaluation ◽  
Consensus Recommendation ◽  
Current Role ◽  
New Class ◽  
Response Evaluation Criteria

Response evaluation criteria in solid tumors (RECIST) are a method used to evaluate and document the response to cancer treatment in solid tumors. The availability of a new class of immuneoncology drugs has resulted in the need to modify RECIST criteria methodology. The first leadership immuno-oncology network (LION) master course brought together experts in oncology and immuno-oncology. Six questions were put to the experts and their opinion, supporting evidence, and experience were discussed to arrive at a practical consensus recommendation. n this nascent field, the availability of a practical consensus recommendation developed by experts in the field is of immense value to the community oncologist and other health-care consultants.

Role of Self Help Groups A Study with Specific Reference to Vellore District

GIS Business ◽  
2019 ◽  
Vol 14 (6) ◽  
pp. 243-252
Author(s):  
Dr. M.A. Bilal Ahmed ◽  
Dr. S. Thameemul Ansari
Keyword(s):  
Leadership Role ◽  
Three Dimensions ◽  
Specific Reference ◽  
Government Organizations ◽  
Research Article ◽  
Self Help ◽  
The People ◽  
The World ◽  
Self Help Groups

SHG is a movement which came to being in the early 1969. Prof. Muhammed Younus, a great economist of Bangladesh took initiative in setting up Self Help Groups and these SHGs were gradually spread all over the world. This social movement unites the people hailing from poor background. Those who are joining this group feel socially and economically responsible to one another. In India, there are some likeminded bodies and stakeholders of some government organizations play pivotal role towards the formation of SHG In this research article, role of SHGs in Vellore district is studies under the three dimensions of Cognitive role, leadership role and role towards entrepreneurship.

The role of surface chemical states on the photocatalytic behavior of all-inorganic mixed halide perovskite nanocrystals

2019 ◽  
Author(s):  
Andrés Fabián Gualdrón-Reyes ◽  
Iván Mora-Seró ◽  
Eliseo Amado-González ◽  
Jorge-Enrique Rueda-P ◽  
Rogelio Ospina ◽  
...  
Keyword(s):  
Surface Chemical ◽  
Perovskite Nanocrystals ◽  
Chemical States ◽  
Halide Perovskite

scholarly journals Psychological contract breach and voluntary turnover among newcomers: the role of supervisor trustworthiness and negative affectivity

2021 ◽  
pp. 1-21
Author(s):  
Émilie Lapointe ◽  
Christian Vandenberghe
Keyword(s):  
Psychological Contract ◽  
Negative Affectivity ◽  
Voluntary Turnover ◽  
Three Dimensions ◽  
Psychological Contract Breach ◽  
Contract Breach ◽  
Indirect Relationship ◽  
Relationship Of ◽  
The Relationship

Abstract This article looks at the relationship between psychological contract breach and voluntary turnover among newcomers, using supervisor trustworthiness as a mediator and negative affectivity as a moderator. Relying on data from 243 newcomers, psychological contract breach was found to be negatively related to the three dimensions of supervisor trustworthiness, i.e., ability, benevolence, and integrity. Supervisor integrity further mediated a positive relationship between psychological contract breach and voluntary turnover measured 8 months later. Psychological contract breach interacted with negative affectivity such that it was less negatively related to dimensions of supervisor trustworthiness at high levels of negative affectivity. The indirect relationship of psychological contract breach to voluntary turnover as mediated by supervisor integrity was also weaker at high levels of negative affectivity. We discuss the implications of these findings for research and practice.

Intolerance of Uncertainty, Anxiety, and Career Indecision: A Mediation Model

2021 ◽  
pp. 106907272110025
Author(s):  
Consuelo Arbona ◽  
Weihua Fan ◽  
Ayoung Phang ◽  
Norma Olvera ◽  
Marcel Dios
Keyword(s):  
College Students ◽  
Decision Making ◽  
Intolerance Of Uncertainty ◽  
Career Decision ◽  
Career Indecision ◽  
Three Dimensions ◽  
Career Decision Making ◽  
Lack Of Information ◽  
Path Analyses

Intolerance of uncertainty (IU) refers to the tendency to fear the unknown and to worry excessively about potential future negative outcomes. In the career decision-making process, college students experience uncertainty regarding the future of occupational opportunities and the evolution of their interests and capabilities. Anxiety is a well-established predictor of career indecision. Therefore, this study examined the role of anxiety as a mediator in the relation of IU and rumination to three dimensions of career decision making difficulties among college students ( N = 678). Results of path analyses indicated that as hypothesized, after controlling for age, intolerance of uncertainty was directly and indirectly (though anxiety) related to the three dimensions of career decision making difficulties: lack of readiness, lack of information, and inconsistent information. Results suggested that career choice interventions may be enhanced with a targeted emphasis on coping with the uncertainty involved in career decision making among college students.

scholarly journals Role of Bi3+ ions on structural, optical, photoluminescence and electrical performance of Cd0.9-xZn0.1BixS QDs

2021 ◽  
Vol 3 (7) ◽  
Author(s):  
A. Krishnamoorthy ◽  
P. Sakthivel ◽  
I. Devadoss ◽  
V. M. Anitha Rajathi
Keyword(s):  
Band Gap ◽  
Optical Band Gap ◽  
Optical Transmittance ◽  
Electrical Performance ◽  
Chemical Route ◽  
Red Emission ◽  
The Mean ◽  
Cubic Structure ◽  
Cyclic Voltammetry Analysis

AbstractIn this work, the Cd0.9-xZn0.1BixS QDs with different compositions of Bi3+ ions (0 ≤ x ≤ 0.05) were synthesized using a facile chemical route. The prepared QDs were characterized for analyzing the structural, morphological, elemental, optical, band gap, photoluminescence and electrochemical properties. XRD results confirmed that the Cd0.9-xZn0.1BixS QDs have a cubic structure. The mean crystallite size was increased from ~ 2 to ~ 5 nm for the increase of Bi3+ ions concentration. The optical transmittance behavior was decreased with increasing Bi3+ ions. The scanning electron microscope images showed that the prepared QDs possessed agglomerated morphology and the EDAX confirmed the presence of doped elements as per stoichiometry ratio. The optical band gap was slightly blue-shifted for initial substitution (Bi3+  = 1%) of Bi3+ ions and red-shifted for further increase of Bi3+ compositions. The optical band gap was ranged between 3.76 and 4.0 eV. High intense red emission was received for Bi3+ (1%) doped Zn:CdS QDs. The red emission peaks were shifted to a higher wavelength side due to the addition of Bi3+ ions. The PL emission on UV-region was raised for Bi3+ (1%) and it was diminished. Further, a violet (422 nm) and blue (460 nm) emission were received for Bi3+ ions doping. The cyclic voltammetry analysis showed that Bi3+ (0%) possessed better electrical properties than other compositions of Bi3+ ions.

scholarly journals Recent Advances in Fabrication of Non-Isocyanate Polyurethane-Based Composite Materials

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3497
Author(s):  
Piotr Stachak ◽  
Izabela Łukaszewska ◽  
Edyta Hebda ◽  
Krzysztof Pielichowski
Keyword(s):  
Raw Materials ◽  
Synthesis Method ◽  
Polymeric Materials ◽  
Original Research ◽  
Significant Group ◽  
Oh Groups ◽  
New Class ◽  
Hazardous Chemical ◽  
Wide Range

Polyurethanes (PUs) are a significant group of polymeric materials that, due to their outstanding mechanical, chemical, and physical properties, are used in a wide range of applications. Conventionally, PUs are obtained in polyaddition reactions between diisocyanates and polyols. Due to the toxicity of isocyanate raw materials and their synthesis method utilizing phosgene, new cleaner synthetic routes for polyurethanes without using isocyanates have attracted increasing attention in recent years. Among different attempts to replace the conventional process, polyaddition of cyclic carbonates (CCs) and polyfunctional amines seems to be the most promising way to obtain non-isocyanate polyurethanes (NIPUs) or, more precisely, polyhydroxyurethanes (PHUs), while primary and secondary –OH groups are being formed alongside urethane linkages. Such an approach eliminates hazardous chemical compounds from the synthesis and leads to the fabrication of polymeric materials with unique and tunable properties. The main advantages include better chemical, mechanical, and thermal resistance, and the process itself is invulnerable to moisture, which is an essential technological feature. NIPUs can be modified via copolymerization or used as matrices to fabricate polymer composites with different additives, similar to their conventional counterparts. Hence, non-isocyanate polyurethanes are a new class of environmentally friendly polymeric materials. Many papers on the matter above have been published, including both original research and extensive reviews. However, they do not provide collected information on NIPU composites fabrication and processing. Hence, this review describes the latest progress in non-isocyanate polyurethane synthesis, modification, and finally processing. While focusing primarily on the carbonate/amine route, methods of obtaining NIPU are described, and their properties are presented. Ways of incorporating various compounds into NIPU matrices are characterized by the role of PHU materials in copolymeric materials or as an additive. Finally, diverse processing methods of non-isocyanate polyurethanes are presented, including electrospinning or 3D printing.

scholarly journals Analyzing input quality along three dimensions: interactive, linguistic, and conceptual

2019 ◽  
Vol 47 (1) ◽  
pp. 5-21 ◽  
Author(s):  
Meredith L. ROWE ◽  
Catherine E. SNOW
Keyword(s):  
Socioeconomic Status ◽  
Early Childhood ◽  
Language Learning ◽  
Pretend Play ◽  
Three Dimensions ◽  
Book Reading ◽  
Future Research ◽  
Input Quality ◽  
Children's Development

AbstractThis paper provides an overview of the features of caregiver input that facilitate language learning across early childhood. We discuss three dimensions of input quality: interactive, linguistic, and conceptual. All three types of input features have been shown to predict children's language learning, though perhaps through somewhat different mechanisms. We argue that input best designed to promote language learning is interactionally supportive, linguistically adapted, and conceptually challenging for the child's age/level. Furthermore, input features interact across dimensions to promote learning. Some but not all qualities of input vary based on parent socioeconomic status, language, or culture, and contexts such as book-reading or pretend play generate uniquely facilitative input features. The review confirms that we know a great deal about the role of input quality in promoting children's development, but that there is much more to learn. Future research should examine input features across the boundaries of the dimensions distinguished here.

Agronomic, breeding, and biotechnological approaches to parasitic plant management through manipulation of germination stimulant levels in agricultural soils

Botany ◽  
2011 ◽  
Vol 89 (12) ◽  
pp. 813-826 ◽  
Author(s):  
M. Fernández-Aparicio ◽  
J.H. Westwood ◽  
D. Rubiales
Keyword(s):  
Mycorrhizal Fungi ◽  
Agricultural Soils ◽  
Host Recognition ◽  
Plant Management ◽  
Parasitic Weed ◽  
Germination Stimulant ◽  
New Class ◽  
Agronomic Practices ◽  
Number Of Plant Species

A number of plant species have adapted to parasitize other plants, and some parasitic species pose severe constraints to major crops. The role of strigolactones and other metabolites present in host root exudates as germination stimulants for weedy root parasitic weed seeds has been known for the last 40 years. Recently, the ecological and developmental roles of strigolactones have been clarified by the discovery that they are a new class of plant hormone that controls shoot branching and serve as host recognition signals for mycorrhizal fungi. Parasitic plants also recognize these chemicals and use them to coordinate their life cycle with that of their host. Here we review agronomic practices that use parasitic germination stimulant production as a target for manipulation to control parasitic weeds.

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