scholarly journals Yeasts Biodiversity and Its Significance: Case Studies in Natural and Human-Related Environments, Ex Situ Preservation, Applications and Challenges

10.5772/23906 ◽  
2011 ◽  
Author(s):  
Enrique Javier Carvajal Barriga ◽  
Diego Libkind ◽  
Ana Isabel ◽  
Juan Ubeda ◽  
Patricia Portero ◽  
...  
Keyword(s):  
Case Studies ◽  
Ex Situ

scholarly journals Conservación in situ y ex situ de las agaváceas y nolináceas mexicanas

2017 ◽  
pp. 27
Author(s):  
Irma Sonia Franco-Martínez
Keyword(s):  
Case Studies ◽  
Ex Situ Conservation ◽  
Selective Extraction ◽  
Ex Situ ◽  
Natural Areas ◽  
Yucca Schidigera ◽  
Risk Of Extinction ◽  
Protected Natural Areas ◽  
Plant Families

The Agavaceae and Nolinaceae, as other plant families, have been affected by the destruction and modification of their habitats and by selective extraction with commercial purposes of some of their species. This has generated that 48 species of Agavaceae and Nolinaceae have been included in the list of Mexican plants in risk of extinction (NOM-059-ECOL-l 994), and two of them (Agave parviflora and Agave victoriae-reginae) are listed in the appendices of CITES. There are 30 Protected Natural Areas that conserve in situ at least one species of the Agavaceae or Nolinaceae. The ex situ conservation is done in 38 Botanical Gardens, 22 of them include in their collections at least one species of these families. There are also eight commercial nurseries that have started the propagation by seed of 12 species, mainly from the genus Agave. Case studies on Agave victoriae-reginae, Beaucarnea recurvata and Yucca schidigera, are also analyzed.

An in situ and ex situ TEM study of the formation of thin cobalt silicide films by molecular beam epitaxy on the silicon (100) surface

1988 ◽  
Vol 46 ◽  
pp. 884-885
Author(s):  
D. Loretto ◽  
J. M. Gibson ◽  
S. M. Yalisove ◽  
R. T. Tung
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Defect Density ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Ex Situ ◽  
Metal Base ◽  
In Situ Experiments ◽  
Potential Applications

The cobalt disilicide/silicon system has potential applications as a metal-base and as a permeable-base transistor. Although thin, low defect density, films of CoSi2 on Si(111) have been successfully grown, there are reasons to believe that Si(100)/CoSi2 may be better suited to the transmission of electrons at the silicon/silicide interface than Si(111)/CoSi2. A TEM study of the formation of CoSi2 on Si(100) is therefore being conducted. We have previously reported TEM observations on Si(111)/CoSi2 grown both in situ, in an ultra high vacuum (UHV) TEM and ex situ, in a conventional Molecular Beam Epitaxy system.The procedures used for the MBE growth have been described elsewhere. In situ experiments were performed in a JEOL 200CX electron microscope, extensively modified to give a vacuum of better than 10-9 T in the specimen region and the capacity to do in situ sample heating and deposition. Cobalt was deposited onto clean Si(100) samples by thermal evaporation from cobalt-coated Ta filaments.

The use of transmission and analytical electron microscopy in studying reactions and phase transformations in thin film

1993 ◽  
Vol 51 ◽  
pp. 842-843
Author(s):  
K. Barmak
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Phase Transformations ◽  
Analytical Electron Microscopy ◽  
Ex Situ ◽  
Multilayer Thin Films ◽  
Absolute Concentration ◽  
Analytical Electron ◽  
Deposition Step

Generally, processing of thin films involves several annealing steps in addition to the deposition step. During the annealing steps, diffusion, transformations and reactions take place. In this paper, examples of the use of TEM and AEM for ex situ and in situ studies of reactions and phase transformations in thin films will be presented.The ex situ studies were carried out on Nb/Al multilayer thin films annealed to different stages of reaction. Figure 1 shows a multilayer with dNb = 383 and dAl = 117 nm annealed at 750°C for 4 hours. As can be seen in the micrograph, there are four phases, Nb/Nb3-xAl/Nb2-xAl/NbAl3, present in the film at this stage of the reaction. The composition of each of the four regions marked 1-4 was obtained by EDX analysis. The absolute concentration in each region could not be determined due to the lack of thickness and geometry parameters that were required to make the necessary absorption and fluorescence corrections.

Transmission Electron Microscopy of Epitaxial silicides grown by ultra high vacuum deposition

1989 ◽  
Vol 47 ◽  
pp. 462-463
Author(s):  
D. Loretto ◽  
J. M. Gibson ◽  
S. M. Yalisove
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Diffraction ◽  
High Vacuum ◽  
High Energy ◽  
Energy Electron ◽  
Ultra High Vacuum ◽  
Ex Situ ◽  
Transmission Electron

The silicides CoSi2 and NiSi2 are both metallic with the fee flourite structure and lattice constants which are close to silicon (1.2% and 0.6% smaller at room temperature respectively) Consequently epitaxial cobalt and nickel disilicide can be grown on silicon. If these layers are formed by ultra high vacuum (UHV) deposition (also known as molecular beam epitaxy or MBE) their thickness can be controlled to within a few monolayers. Such ultrathin metal/silicon systems have many potential applications: for example electronic devices based on ballistic transport. They also provide a model system to study the properties of heterointerfaces. In this work we will discuss results obtained using in situ and ex situ transmission electron microscopy (TEM).In situ TEM is suited to the study of MBE growth for several reasons. It offers high spatial resolution and the ability to penetrate many monolayers of material. This is in contrast to the techniques which are usually employed for in situ measurements in MBE, for example low energy electron diffraction (LEED) and reflection high energy electron diffraction (RHEED), which are both sensitive to only a few monolayers at the surface.

Interfacial properties of GaSb/InAs superlattices

1993 ◽  
Vol 51 ◽  
pp. 826-827
Author(s):  
M. E. Twigg ◽  
B. R. Bennett ◽  
J. R. Waterman ◽  
J. L. Davis ◽  
B. V. Shanabrook ◽  
...  
Keyword(s):  
Gaas Substrate ◽  
Molecular Beam ◽  
Infrared Detector ◽  
Interfacial Properties ◽  
Ex Situ ◽  
X Ray Diffraction ◽  
Absorption Coefficients ◽  
X Ray ◽  
Short Period ◽  
High Optical Absorption

Recently, the GaSb/InAs superlattice system has received renewed attention. The interest stems from a model demonstrating that short period Ga1-xInxSb/InAs superlattices will have both a band gap less than 100 meV and high optical absorption coefficients, principal requirements for infrared detector applications. Because this superlattice system contains two species of cations and anions, it is possible to prepare either InSb-like or GaAs-like interfaces. As such, the system presents a unique opportunity to examine interfacial properties.We used molecular beam epitaxy (MBE) to prepare an extensive set of GaSb/InAs superlattices grown on an GaSb buffer, which, in turn had been grown on a (100) GaAs substrate. Through appropriate shutter sequences, the interfaces were directed to assume either an InSb-like or GaAs-like character. These superlattices were then studied with a variety of ex-situ probes such as x-ray diffraction and Raman spectroscopy. These probes confirmed that, indeed, predominantly InSb-like and GaAs-like interfaces had been achieved.

Corporate Sustainability: Challenge to Managerial Orthodoxies

2003 ◽  
Vol 9 (1) ◽  
pp. 2-11 ◽  
Author(s):  
Dexter Dunphy
Keyword(s):  
Case Studies ◽  
Corporate Sustainability ◽  
Central Place ◽  
Marked Contrast ◽  
Sustainability Management

ABSTRACTThis paper addresses the issue of corporate sustainability. It examines why achieving sustainability is becoming an increasingly vital issue for society and organisations, defines sustainability and then outlines a set of phases through which organisations can move to achieve increasing levels of sustainability. Case studies are presented of organisations at various phases indicating the benefits, for the organisation and its stakeholders, which can be made at each phase. Finally the paper argues that there is a marked contrast between the two competing philosophies of neo-conservatism (economic rationalism) and the emerging philosophy of sustainability. Management schools have been strongly influenced by economic rationalism, which underpins the traditional orthodoxies presented in such schools. Sustainability represents an urgent challenge for management schools to rethink these traditional orthodoxies and give sustainability a central place in the curriculum.

Short-Form Application of the Screening Test of Spanish Grammar and the Northwestern Syntax Screening Test to Latino Children

1978 ◽  
Vol 9 (4) ◽  
pp. 220-235
Author(s):  
David L. Ratusnik ◽  
Carol Melnick Ratusnik ◽  
Karen Sattinger
Keyword(s):  
New York ◽  
Case Studies ◽  
Metropolitan Area ◽  
Screening Test ◽  
Normative Data ◽  
Short Form ◽  
Latino Children ◽  
Data Application ◽  
York Metropolitan Area ◽  
Multiple Regression Technique

Short-form versions of the Screening Test of Spanish Grammar (Toronto, 1973) and the Northwestern Syntax Screening Test (Lee, 1971) were devised for use with bilingual Latino children while preserving the original normative data. Application of a multiple regression technique to data collected on 60 lower social status Latino children (four years and six months to seven years and one month) from Spanish Harlem and Yonkers, New York, yielded a small but powerful set of predictor items from the Spanish and English tests. Clinicians may make rapid and accurate predictions of STSG or NSST total screening scores from administration of substantially shortened versions of the instruments. Case studies of Latino children from Chicago and Miami serve to cross-validate the procedure outside the New York metropolitan area.

Case Studies for Telepractice in AAC

2014 ◽  
Vol 23 (1) ◽  
pp. 42-54 ◽  
Author(s):  
Tanya Rose Curtis
Keyword(s):  
Service Delivery ◽  
Case Studies ◽  
Eye Gaze ◽  
Cognitive Impairments ◽  
Perceived Barriers ◽  
Computer Experience ◽  
Access Methods ◽  
Complex Communication Needs ◽  
Barriers To Service ◽  
Communication Needs

As the field of telepractice grows, perceived barriers to service delivery must be anticipated and addressed in order to provide appropriate service delivery to individuals who will benefit from this model. When applying telepractice to the field of AAC, additional barriers are encountered when clients with complex communication needs are unable to speak, often present with severe quadriplegia and are unable to position themselves or access the computer independently, and/or may have cognitive impairments and limited computer experience. Some access methods, such as eye gaze, can also present technological challenges in the telepractice environment. These barriers can be overcome, and telepractice is not only practical and effective, but often a preferred means of service delivery for persons with complex communication needs.

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