• Explosives and Blasting
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• v.30 no.1
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• pp.52-59
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• 2012

Fragmentation is one factor to affect productivity and economic efficiency of mine. Authors investigate the blasting pattern and improve it step by step while observing the fragmentation results. Final pattern was suggested and the fragmentation improved 24 % compared to traditional pattern, with 50 % is passing rate.

• Mass Spectrometry Letters
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• v.10 no.2
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• pp.50-55
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• 2019

The fragmentation statistics of ion trap CID (Collision-Induced Dissociation) spectra using 87,661 tandem mass spectra of doubly charged tryptic peptides are analyzed here. In contrast to the usual method of using intensity information, the frequency of occurrence of fragment ions, with respect to the position of the cleavage site and the residues at these sites is studied in this paper. The analysis shows that the frequency of occurrence of fragment ion peaks is more towards the middle of the peptide than its ends. It was noted that amino acid with an aromatic and basic side chain at N- & C- terminal end of the peptide stimulates more peaks at the lower end of the spectrum. The residue pair effect was shown when the amide bond occurs between acidic and basic residues. The fragmentation at these sites (D/E-H/R/K) stimulates the generation of the y-ion peak. Also, the cleavage site H-H/R/K stimulates the generation of b-ions. K-P environment in the peptide sequence has more tendency to generate y-ions than b-ions. Statistical analysis helps in the visualization of the CID fragmentation pattern. Cleavage pattern along the length of the peptide and the residue pair effects, enhance the knowledge of fragmentation behavior, which is useful for the better interpretation of tandem mass spectra.

• Clinical and Experimental Reproductive Medicine
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• v.46 no.4
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• pp.147-151
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• 2019

Objective: The aim of this study was to investigate DNA fragmentation status in human spermatozoa according to specific tail swelling patterns determined via hypo-osmotic swelling test (HOST). Methods: Frozen semen samples from 21 healthy donors were thawed and prepared by the swim-up technique for use in intracytoplasmic sperm injection. The semen samples were treated for 5 minutes as part of the HOST procedure and then underwent the sperm chromatin dispersion test using a Halosperm kit. DNA fragmentation status (large halo, medium halo, small halo, no halo, or degraded) and the specific tail swelling pattern ("a"-"g") were assessed at the level of a single spermatozoon. A total of 42,000 spermatozoa were analyzed, and the percentage of spermatozoa without DNA fragmentation (as evidenced by a large or medium halo) was assessed according to the specific tail swelling patterns observed. Results: The HOST examinations showed that > 93% of spermatozoa across all types displayed no DNA fragmentation. The percentage of spermatozoa without DNA fragmentation was 100% in type "d", 98.67% in type "g", and 98.17% in type "f" spermatozoa. Conclusion: We found that the type "d" spermatozoa displayed no DNA fragmentation, but the other types of spermatozoa also displayed very low rates of DNA fragmentation. This result may be associated with the processing of the spermatozoa by density gradient centrifugation and the swim-up technique.

• Tunnel and Underground Space
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• v.20 no.5
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• pp.325-331
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• 2010

In the present research paper large scale blasting was conducted on two different firing patterns, namely, straight V type and skewed V type pattern on the same sandstone overburden bench with similar explosives. The post-blast fragmentation assessments were made by use of digital imaging technique. The total cycle time of 10 $m^3$ rope shovels was also recorded in the field. The results reveal improvements in the fragmentation and excavator performance results for the blasts fired on skewed V type pattern. The paper discusses the skewed V firing pattern and the reasons for its superior performance vis-$\grave{a}$-vis the straight V type pattern.

• Journal of the Korean Institute of Landscape Architecture
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• v.35 no.6
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• pp.37-47
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• 2008

Recently, reckless exploitation of land resources without much consideration for the environmental value of the land has been witnessed to accommodate the ever-increasing demands for regional development. Fragmentation due to land development is a major reason for the declining biodiversity in forest ecosystems. The purposes of this study were (1) to investigate the relationship between the factors of land development and forest fragmentation in 13 watersheds of a metropolitan area and (2) to suggest a forest management plan through the relationship. We carried out a factor analysis to determine explanatory axes of forest fragmentation, and then conducted a correlation analysis between the factor scores and the factor of land development, such as the rate of built-up areas, road density, number of built-up patches, and area of housing developments. The first explanatory axis represented stability of landscape highly related with the rate of the built-up area and road density. The second axis represented the level of fragment highly related with a number of built-up patches. Forest fragmentation patterns of the 13 watersheds were classified for the similarity in forest fragmentation. This study presents the forest management plans including distribution and level of land development and forest conservation.

• Mass Spectrometry Letters
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• v.12 no.4
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• pp.159-162
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• 2021

The fragmentation pattern of four hindered phenol antioxidants was investigated using ammonium and lithium ions as the additives for ionization. Due to different binding geometries and interactions, they underwent different characteristic fragmentation reactions providing useful complementary information for structural analysis of hindered phenol antioxidants. Ammonium ion adducts were fragmented successively until all t-butyl groups were lost in the form of isobutylene and allowed the estimation of the number of t-butyl groups present in the molecule. Lithium ion adducts produced fragment ions from major backbone cleavage, on the other hand, which provide more crucial information for the identification of detailed backbone structure.

• Explosives and Blasting
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• v.41 no.4
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• pp.41-50
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• 2023

This study, a vertical double-deck method using an electronic detonator was applied to increase excavation volume and reduce blast pollution. In the double deck method, there is a possibility that blasting efficiency may be reduced if bottom deck blasting is carried out without the free surface being completely formed after upper deck blasting. And for this reason, the blasting efficiency of the double deck method varies depending on the deck delay time. Therefore, in this study, we proposed four deck delay times applying 1 to 5 times the hole delay time. And blasting efficiency was evaluated according to fragmentation analysis. As a result of the fragmentation evaluation, the fragmentation of pattern 4 (deck delay time = hole delay time×5) was the best, but it was confirmed that fragmentation efficiency increased significantly from pattern 3 (deck delay time = hole delay time×3). Accordingly, it is analyzed that when blasting a vertical double deck, the deck delay time must be at least three times the hole delay time to obtain an efficient blasting effect.

• Bulletin of the Korean Chemical Society
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• v.19 no.7
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• pp.721-723
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• 1998

• Journal of Environmental Impact Assessment
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• v.11 no.3
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• pp.117-127
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• 2002

This study tested the usefulness of landscape indices for quantifying forest fragmentation due to linear development projects. Research was carried out in the middle-upper Nakdong River watershed, which has been affected by the expressway building, or national road-widening. Landscape indices were calculated from the forest cover maps before and after road-building using FRAGSTATS 3.1. We could successfully demonstrate the forest fragmentation based on landscape indices; (1) patch size decreased, and edge density and patch density increased (2) roads simplified patch shapes, especially in the larger patches, (3) patch core area size decreased, and core area density increased, (4) the distance increased between the focal patch and each of the other patches within the search radius (=1km) as a result of roads. We suggest several important needs for future researches, including continued investigation of scaling issues, development of indices that measure specific components of spatial pattern, and study of the relationships between forest fragmentation and ecological processes.

• Mass Spectrometry Letters
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• v.12 no.2
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• pp.41-46
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• 2021

Collision-induced dissociation (CID) and higher-energy collisional dissociation (HCD) are the widely used fragmentation technique in mass spectrometry-based proteomics studies. Understanding the fragmentation pattern from the tandem mass spectra using statistical methods helps to implement efficient spectrum analysis algorithms. The study characterizes the frequency of occurrence of multi-charged fragment ions and their neutral loss events of doubly and triply charged peptides in the CID and HCD spectrum. The dependency of the length of the fragment ion on the occurrence of multi-charged fragment ion is characterized here. Study shows that the singly charged fragment ions are generally dominated in the doubly charged peptide spectrum. However, as the length of the product ion increases, the frequency of occurrence of charge 2 fragment ions increases. The y- ions have more tendencies to generate charge 2 fragment ions than b- ions, both in CID and HCD spectrum. The frequency of occurrence of charge 2 fragment ion peaks is prominent upon the dissociation of the triply charged peptides. For triply charged peptides, product ion of higher length occurred in multiple charge states in CID spectrum. The neutral loss peaks mostly exist in charge 2 states in the triply charged peptide spectrum. The b-ions peaks are observed in much less frequency than y-ions in HCD spectrum as the length of the fragment increases. Isotopic peaks are occurred in charge 2 state both in doubly and triply charged peptide's HCD spectrum.