scholarly journals Floristic diversity of the soil weed seedbank in boro rice fields: in situ and ex situ evaluation

2018 ◽  
Vol 16 (3) ◽  
pp. 396-402
Author(s):  
Fahmida Akter ◽  
Mahfuza Begum ◽  
Md. Abdus Salam
Keyword(s):  
Shannon Index ◽  
Ex Situ ◽  
Floristic Diversity ◽  
Weed Species ◽  
Importance Value ◽  
Emergence Period ◽  
Research Fields ◽  
Weed Survey ◽  
Boro Rice

This study was conducted at the research fields of Agronomy Field Laboratory and in the net house of Department of Agronomy, Bangladesh Agricultural University, Mymensingh. The objective of this study was to compare the in situ and ex situ floristic diversity of soil weed seedbank in boro rice. The soil weed seedbank status was observed through weed survey at research fields and seed germination method in the net house. Five fields were selected randomly with four replications. Soil samples were collected to a depth up to 15 cm and placed in plastic pots in the net house. Weed seedlings that emerged were identified, counted and removed at 30 day intervals throughout the four months emergence period. At the same time, weed survey was done using a 0.25 m–2 quadrate. Diversity was computed by the Shannon index (H’). Under in situ condition, 31 weed species belonging to 15 families germinated and 33 weed species belonging to 17 families germinated under ex situ condition. The family Cyperaceae had the highest species richness under both in situ and ex situ conditions. The five most dominant weed species under in situ condition based on importance value were Eleocharis atroperpurea > Cyperus difformis > Echinochloa crusgalli > Monochoria vaginalis > Lindernia antipoda whereas, under ex situ condition, two new weed species, Fimbristylis miliacea and Echinochloa colonum were observed in the dominant list instead of Monochoria vaginalis and Lindernia antipoda having slightly different rank and order. The ex situ density was 2721 plants m–2, approximately four times higher than the 700 plants m–2 observed under in situ situation and similarly ex situ condition had higher Shannon Index (H’) value (H’=2.412) indicating greater diversity than in situ (H’=2.211) condition. The information obtained from the study would help determine the infestation potential of identified species, which could lead to improved management strategies. J. Bangladesh Agril. Univ. 16(3): 396–402, December 2018

scholarly journals Floristic diversity of the soil weed seed bank in a rice-growing area of Brazil: in situ and ex situ evaluation

2013 ◽  
Vol 27 (3) ◽  
pp. 465-471 ◽  
Author(s):  
Mário Luiz Ribeiro Mesquita ◽  
Leonaldo Alves de Andrade ◽  
Walter Esfrain Pereira
Keyword(s):  
Seed Bank ◽  
Ex Situ ◽  
Floristic Diversity ◽  
Weed Seed

scholarly journals Quantitative assessment and status of ethnomedicinal plants of Sheen Ghar Valley, Dir Lower, Khyber Pakhtunkhwa, Pakistan

2020 ◽  
Vol 7 (1) ◽  
pp. 17-22
Author(s):  
Shariat Ullah ◽  
Lal Badshah ◽  
Asghar Ali ◽  
Noor Muhammad
Keyword(s):  
Hypericum Perforatum ◽  
In Situ Conservation ◽  
Ex Situ ◽  
Current Status ◽  
Importance Value ◽  
Plant Family ◽  
Medicinal Uses ◽  
Whole Plants ◽  
Family Importance Value

This study was conducted from March 2017 to August 2018, to enumerate the quantitative attributes and current status of medicinal plants of Sheen Ghar Valley, District Dir Lower, Pakistan. A total of 51 species were documented for their medicinal uses. These plants belonged to 31 families. Results of this study revealed that leaves were the frequently used part (50%), followed by whole plants (only 30%) in curing different ailments. Many plants were found to be having multiple uses. Based on family importance value (FIV), Lamiaceae was the leading plant family (126.30) followed by Violaceae (55.81), while highest relative frequency of citation (RFC) was noted for Viola canescens (0.558) followed by Olea europaea (0.523). Conservation study revealed that 24 species (47%) were vulnerable, 22 species (43%) were rare and 4 species (8%) were noted as infrequent. Following IUCN standards for conservation, one species i.e. Hypericum perforatum was declared dominant. This study recommends immediate ex-situ and in-situ conservation programme for protecting the plant wealth of the locality.

scholarly journals Diversity of Weed Species in Farms Kisii Central Sub-County, Western Kenya

2019 ◽  
Vol 6 ◽  
pp. 11-19
Author(s):  
Charles N. Nyamwamu ◽  
Rebecca Karanja ◽  
Peter Mwangi
Keyword(s):  
Species Diversity ◽  
Cynodon Dactylon ◽  
Shannon Index ◽  
Line Transect ◽  
Cyperus Esculentus ◽  
Weed Species ◽  
Bidens Pilosa ◽  
Importance Value ◽  
Western Kenya ◽  
Equal Distance

This study sought to determine species diversity and Importance Values (IV) of weeds in farms in Kisii Central Sub County, Western Kenya. Eight administrative sub-locations were randomly selected. Ten farms were selected at equal distance along transect laid across each sub-location. Quadrant and a line transect laid across each farm were used to collect weed species. Five rectangular quadrants of 0.5x2m were established in each farm and individuals of each weed species identified and counted. Importance value (IV) for each weed species was computed from density, frequency and abundance. Diversity was computed by Shannon index (H’). Twenty four weed species from 22 genera in 10 families were recorded, Family Asteraceae had the highest number of species (6), followed by Solanaceae and Poaceae with 4 and 3 species respectively. The dominant weed species were Galinsoga parviflora(IV=241.6%), Pennisetum clandestinum(IV=215.8.7%),Bidens pilosa(IV=196.7%), Cynodon dactylon (IV=192.4%), Digitaria scalarum(IV=180.8%) and Cyperus esculentus(172.0%). Weed species diversity was higher (H'=2.81).

scholarly journals STRUKTUR VEGETASI SEKITAR JENIS POHON TANDUI (Mangifera rufocustata KOSTREM.) DI HULU SUNGAI SELATAN

2021 ◽  
Vol 9 (2) ◽  
pp. 464
Author(s):  
Adistina Fitriani ◽  
Eva Prihatiningtyas
Keyword(s):  
Hevea Brasiliensis ◽  
Cocos Nucifera ◽  
In Situ Conservation ◽  
Analysis Data ◽  
Ex Situ ◽  
Tree Level ◽  
Importance Value Index ◽  
Importance Value ◽  
Nephelium Lappaceum

This research aims to analyze the vegetation that grow around the tandui plants/ This research done to support for the ex situ and in situ conservation of natural resources,The data collected in this research used proposive sampling methodd with 15 observation plots starting from seedlings, saplings, poles and trees. The analysis data was used the Importance Value Index (INP). The results showed that the seedling rate was dominated by Jambu Air (Syzygium aqueum) 114.65%, Karet (Hevea brasiliensis) 63.38%, Ramania (Bouea macrophylla) 47.92%, sapling rate was dominated by Karet (Hevea brasiliensis) 60.5%, Jambu Biji (Syzygium aqueum) 48.19%, Jingah (Gluta renghas) 41.77%, the pole level was dominated by Karet (Hevea brasiliensis) 175.60%, Rambutan (Nephelium lappaceum) 148.62% , Sungkai (Peronema canescens) 126.64% and the tree level is dominated by Rubber (Hevea brasiliensis) 191.82%, Kelapa (Cocos nucifera) 108.78% and Langsat (Lansium domesticum) 84.60%

Weed Survey Associated in Tobacco (Nicotiana tabacum L.) in Bilatte Tobacco Farm, Ethiopia

2020 ◽  
Vol 1 (1) ◽  
pp. 29-33
Author(s):  
Daniel Abebe ◽  
Mekonnen Tadesse
Keyword(s):  
Relative Abundance ◽  
Cynodon Dactylon ◽  
Datura Stramonium ◽  
Survey Method ◽  
Cyperus Esculentus ◽  
Weed Species ◽  
Importance Value Index ◽  
Importance Value ◽  
Nicotiana Tabacum L ◽  
Weed Survey

An in-field weed survey method was conducted to estimate the most frequently, density and abundance weed species present in Bilatte tobacco farm, Ethiopia during 2014 totally covered approximately 145 hectares. During study period a total number of 14 weed species belonging to 06 monocot and 08 dicot families were recorded out of 7 families of weed reported form study site. The most predominate was shown by monocot Poaceae having 4 weed species followed by dicot family Composite having 3 weeds. The families Cyperaceous, Solanaceae and Amaranthaceous each having 2 weeds, and the family Papaverceae represented by 1 weed. Based on % of frequency Cyperus esculentus (sedges) family Cyperaceous was 99.30. The data showed that Cynodon dactylon and Digitaria abyssinica belong to family Poaceae and Cyperus esculentus family Cyperaceous were the most abundant weed with a density of 35.9, 14 and 12 of plant m-2 respectively. Relative abundance values quantify the overall weed problem posed by specie Cyperus esculentus that had higher relative abundance was 98.97. The importance value index indicated that Cyperaceous and Poaceae families can be considered the great potential to cause reduce tobacco production. Whereas, Solanium nigrum and Datura stramonium were observed with least population density 0.00 and 1.03 plant m-2, least frequently 2.7 and 13.51 %, least relative weed abundance, 0.07 and 1.03 with importance value index 2.8 and 14.8 occurring weed respectively.

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.

Atomic Layer Deposition of LiF and Lithium Ion Conducting (AlF3)(LiF)x Alloys Using Trimethylaluminum, Lithium Hexamethyldisilazide and Hydrogen Fluoride

2017 ◽  
Author(s):  
Younghee Lee ◽  
Daniela M. Piper ◽  
Andrew S. Cavanagh ◽  
Matthias J. Young ◽  
Se-Hee Lee ◽  
...  
Keyword(s):  
Lithium Ion ◽  
Atomic Layer ◽  
Mass Gain ◽  
Alloy Film ◽  
Ex Situ ◽  
X Ray ◽  
Layer Deposition ◽  
Ion Conducting ◽  
Good Agreement

<div>Atomic layer deposition (ALD) of LiF and lithium ion conducting (AlF<sub>3</sub>)(LiF)<sub>x</sub> alloys was developed using trimethylaluminum, lithium hexamethyldisilazide (LiHMDS) and hydrogen fluoride derived from HF-pyridine solution. ALD of LiF was studied using in situ quartz crystal microbalance (QCM) and in situ quadrupole mass spectrometer (QMS) at reaction temperatures between 125°C and 250°C. A mass gain per cycle of 12 ng/(cm<sup>2</sup> cycle) was obtained from QCM measurements at 150°C and decreased at higher temperatures. QMS detected FSi(CH<sub>3</sub>)<sub>3</sub> as a reaction byproduct instead of HMDS at 150°C. LiF ALD showed self-limiting behavior. Ex situ measurements using X-ray reflectivity (XRR) and spectroscopic ellipsometry (SE) showed a growth rate of 0.5-0.6 Å/cycle, in good agreement with the in situ QCM measurements.</div><div>ALD of lithium ion conducting (AlF3)(LiF)x alloys was also demonstrated using in situ QCM and in situ QMS at reaction temperatures at 150°C A mass gain per sequence of 22 ng/(cm<sup>2</sup> cycle) was obtained from QCM measurements at 150°C. Ex situ measurements using XRR and SE showed a linear growth rate of 0.9 Å/sequence, in good agreement with the in situ QCM measurements. Stoichiometry between AlF<sub>3</sub> and LiF by QCM experiment was calculated to 1:2.8. XPS showed LiF film consist of lithium and fluorine. XPS also showed (AlF<sub>3</sub>)(LiF)x alloy consists of aluminum, lithium and fluorine. Carbon, oxygen, and nitrogen impurities were both below the detection limit of XPS. Grazing incidence X-ray diffraction (GIXRD) observed that LiF and (AlF<sub>3</sub>)(LiF)<sub>x</sub> alloy film have crystalline structures. Inductively coupled plasma mass spectrometry (ICP-MS) and ionic chromatography revealed atomic ratio of Li:F=1:1.1 and Al:Li:F=1:2.7: 5.4 for (AlF<sub>3</sub>)(LiF)<sub>x</sub> alloy film. These atomic ratios were consistent with the calculation from QCM experiments. Finally, lithium ion conductivity (AlF<sub>3</sub>)(LiF)<sub>x</sub> alloy film was measured as σ = 7.5 × 10<sup>-6</sup> S/cm.</div>

A New Method of Wafer Level Plan View TEM Sample Preparation by DualBeam

2008 ◽  
Author(s):  
Hyoung H. Kang ◽  
Michael A. Gribelyuk ◽  
Oliver D. Patterson ◽  
Steven B. Herschbein ◽  
Corey Senowitz
Keyword(s):  
Sample Preparation ◽  
Ex Situ ◽  
Wafer Level ◽  
Cross Sectional ◽  
Plan View ◽  
Manufacturing Line ◽  
Transmission Electron ◽  
Thin Lamella ◽  
Preparation Techniques

Abstract Cross-sectional style transmission electron microscopy (TEM) sample preparation techniques by DualBeam (SEM/FIB) systems are widely used in both laboratory and manufacturing lines with either in-situ or ex-situ lift out methods. By contrast, however, the plan view TEM sample has only been prepared in the laboratory environment, and only after breaking the wafer. This paper introduces a novel methodology for in-line, plan view TEM sample preparation at the 300mm wafer level that does not require breaking the wafer. It also presents the benefit of the technique on electrically short defects. The methodology of thin lamella TEM sample preparation for plan view work in two different tool configurations is also presented. The detailed procedure of thin lamella sample preparation is also described. In-line, full wafer plan view (S)TEM provides a quick turn around solution for defect analysis in the manufacturing line.

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