Academic literature on the topic 'Damage Percentage'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Damage Percentage.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "Damage Percentage"
1
Demirel, Nihat, and Ömer Konuşkan. "A study on percentages of damage ratios of the European corn borer (ECB), Ostrinia nubilalis (Hübner) (Lepidoptera: Pyralidae) on sweet corn cultivars." Entomology and Applied Science Letters 4, no. 2 (2017): 1. http://dx.doi.org/10.24896/easl2017421.
Full textAbstract:
The European corn borer (ECB), Ostrinia nubilalis (Hübner) (Lepidoptera: Pyralidae) is one of the most important pest of grain corn and sweet corn in Turkey. The objective of this study was to assess percentage damage ratios of the ECB on stalk and corncobs of various sweet corn varieties in Reyhanlı district of Hatay province of Turkey. The studies were carried out in 2015-2016 with four different sweet corn varieties including Caremelo, Vega, Merit and Batem. After two years of the study, the ECB larvae caused significant damages on stalk and corncobs of all sweet corn varieties. The percentage damage of stalk and corncobs varied for each of the sweet corn varieties in both years. In the first year, the highest percentages of stalk damage ratios were recorded on Batem (32.45), followed by Vega (19.85), Merit (17.07) and Caremelo (16.72). In the second year, the highest percentages of stalk damage ratios were observed on Merit (59.34), followed by Caremelo (51.65), Batem (45.09) and Vega (35.49). In the first year, the largest percentages of corncobs damage ratios were recorded on Vega (25.73), followed by Batem (16.74), Caremelo (12.11), and Merit (9.30). In the second year, the highest percentages of corncobs damage ratios were observed on Caremelo (14.31), followed by Merit (13.72), Batem (9.98) and Vega (8.93). In conclusion, the largest percentages of stalk + corncobs damages ratios were observed on Batem (49.19), followed by Vega (45.58), Caremelo (28.83) and Merit (26.37) in 2015, while the highest percentages of stalk + corncobs damages ratios were recorded on Merit (73.06), followed by Caremelo (65.96), Batem (55.07) and Vega (44.42) in 2016.
2
Putri, Anggri Feriditya, Normela Rachmawati, and Dina Naemah. "IDENTIFIKASI KERUSAKAN DAUN PADA TANAMAN BALANGERAN (Shorea balangeran) DI KAWASAN HUTAN DENGAN TUJUAN KHUSUS (KHDTK) TUMBANG NUSA." Jurnal Sylva Scienteae 4, no. 1 (2021): 28. http://dx.doi.org/10.20527/jss.v4i1.3088.
Full textAbstract:
Damage to the plant leaves can affect the health of the plant. The research aims to identify the damage that occurs in the leaves of the Sorea balangeran plant and calculate the percentage (%) of leaf damage. The location of the study was conducted at the Tumbang Nusa KHDTK BP2LHK Banjarbaru, Central Kalimantan, determined by purposive sampling or deliberate data collection with a specified starting point, observing 639 plants on the leaf section in 2015, identifying plants based on the leaf part written in the form of a tallysheet, calculate the percentage of damages to Sorea balangeran. The types of damages that occur in the leaves include holes, rolling, yellowing, perforating and rolling, rolling and inhaling. The dominant damage to the leaf is hollow leaves by 348 and the lowest is yellow roll by 2 with a percentage of 82.26% for leaves with holes and 0.48 for leaf rolling and yellowing. The percentage of damage to the leaves of the balageran plant showed a percentage of 65.72% that on the leaves of the Balangeran plant studied showed that the leaves were not good. The conclusion from the study of the greatest leaf damage occurred due to perforated leaves and the percentage of damage to the leaves as a whole by 65.72%.Keywords: Balangeran, Damage, Leaf, Identification, Forest
3
Ningsih, Ineke Kesuma, Fitri Electrika D. Surawan, and Zulman Efendi. "PHYSICAL QUALITY ANALYSIS OF ‘ROTI MANIS’ AT BAROKAH BAKERY IN LAHAT." Jurnal Agroindustri 5, no. 1 (2015): 20–35. http://dx.doi.org/10.31186/j.agroind.5.1.20-35.
Full textAbstract:
The purpose of this research was to determine the percentage of each type of ‘roti manis’ physical damage, to identify factors causing the damages, and to determine whether the percentage amount of damage was whithin the business control limit. Types of damage observed were broken, too small in size, in appropriate form, over heated or burned. Observation was conducted during 16 working days (one month) at Barokah Bakery in Lahat. Result of the research showed that the broken damage was 1,31%; the too small in size was 1,1%; the unacceptable form was 0,98%; and no damage of over heat. Based on the causal effect analysis, it was found that the main factor causing ‘roti manis’s damages was caused by process inadequately. Result of diagram control analysis showed that the overall average damage was 3,4% with the upper limit was 5,2% and the lower limit was 1,6%. The percentage of the damage was considered high but it was within the company control limit of 2-4%
4
Čermák, Petr, Pavla Beranová, Jindřiška Orálková, Petr Horsák, and Jaroslav Plšek. "Relationships between browsing damage and the species dominance by the highly food-attractive and less food-attractive trees." Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis 59, no. 1 (2011): 29–36. http://dx.doi.org/10.11118/actaun201159010029.
Full textAbstract:
The paper analyses data on the browsing damage to Acer pseudoplatanus, Carpinus betulus, Fraxinus excelsior, Quercus spp., Tilia cordata and Fagus sylvatica. Field research was carried out in the period 2007–2010 and analysed data came from 33 transects at 10 localities with the various abundance of game in the CR (everywhere Capreolus capreolus, on several plots also Cervus elaphus, Ovis musimon or Dama dama). Trees were monitored up to a height of 150 cm in natural regeneration under stands and in plantations and the occurrence was noted of new browsing damage. Differences between the percentage of damaged individuals of the given species of a food-attractive species (A. p., C. b., F. e.) and the percentage of damaged individuals of all tree species on a transect as well as the proportion of these parameters correlate negatively with the given species dominance and thus, they appear to be suitable parameters for the analysis of relationships between the damage intensity and dominance. The higher the percentage proportions of highly food-attractive species and the lower the percentage of less-attractive species, the lower the relative intensity of damage to highly food-attractive species. At the same time, the higher the percentage proportion of highly food-attractive species and the lower the percentage of less-attractive species then the lower a difference between damage to less food-attractive species and all species.
5
Obenland, David, Dennis Margosan, Sue Collin, et al. "Peel Fluorescence as a Means to Identify Freeze-damaged Navel Oranges." HortTechnology 19, no. 2 (2009): 379–84. http://dx.doi.org/10.21273/hortsci.19.2.379.
Full textAbstract:
The use of ultraviolet fluorescence to identify freeze-damaged navel oranges (Citrus sinensis) was evaluated using fruit harvested following a natural freeze that occurred in California in Jan. 2007. Navel oranges were harvested after the freeze from 14 sites that were previously determined to have a slight to moderate amount of freeze damage. The fruit were evaluated for the presence of small yellow spots characteristic of freeze damage that fluoresce when viewed under a ultraviolet-A (365 nm) source and were then cut and rated using a method currently used by the California Department of Food and Agriculture (CDFA) to determine the presence of internal freeze damage. The percentage of freeze-damaged fruit in each lot as determined by the CDFA method ranged from 0% to 89%. The accuracy of classifying fruit as freeze damaged in each lot by peel fluorescence averaged 44%, with the fruit lots containing the greatest amount of freeze damage having the highest classification percentages. False-positives occurred at a lower rate than false-negatives among the lots. Although some fading was evident, the fluorescence persisted and was readily visible for at least 9 weeks after the freeze event. Removal of fruit with ultraviolet peel fluorescence was ineffective in reducing the percentage of damaged fruit within the examined lots. In the second part of the test, eighteen lots of potentially freeze-damaged fruit were obtained from a packing house, immediately evaluated for freeze damage using ultraviolet light, and then after 4 weeks of storage, were evaluated again using the CDFA method. Fruit that had a slight to moderate degree of freeze damage were tasted and evaluated for sensory characteristics. Both methods of freeze damage detection were poorly related to the sensory characteristics.
6
Obenland, David, Dennis Margosan, Sue Collin, et al. "Peel Fluorescence as a Means to Identify Freeze-damaged Navel Oranges." HortTechnology 19, no. 2 (2009): 379–84. http://dx.doi.org/10.21273/horttech.19.2.379.
Full textAbstract:
The use of ultraviolet fluorescence to identify freeze-damaged navel oranges (Citrus sinensis) was evaluated using fruit harvested following a natural freeze that occurred in California in Jan. 2007. Navel oranges were harvested after the freeze from 14 sites that were previously determined to have a slight to moderate amount of freeze damage. The fruit were evaluated for the presence of small yellow spots characteristic of freeze damage that fluoresce when viewed under a ultraviolet-A (365 nm) source and were then cut and rated using a method currently used by the California Department of Food and Agriculture (CDFA) to determine the presence of internal freeze damage. The percentage of freeze-damaged fruit in each lot as determined by the CDFA method ranged from 0% to 89%. The accuracy of classifying fruit as freeze damaged in each lot by peel fluorescence averaged 44%, with the fruit lots containing the greatest amount of freeze damage having the highest classification percentages. False-positives occurred at a lower rate than false-negatives among the lots. Although some fading was evident, the fluorescence persisted and was readily visible for at least 9 weeks after the freeze event. Removal of fruit with ultraviolet peel fluorescence was ineffective in reducing the percentage of damaged fruit within the examined lots. In the second part of the test, eighteen lots of potentially freeze-damaged fruit were obtained from a packing house, immediately evaluated for freeze damage using ultraviolet light, and then after 4 weeks of storage, were evaluated again using the CDFA method. Fruit that had a slight to moderate degree of freeze damage were tasted and evaluated for sensory characteristics. Both methods of freeze damage detection were poorly related to the sensory characteristics.
7
Momin, M. Abdul, Paul A. Wempe, Tony E. Grift, and Alan C. Hansen. "Effects of Four Base Cutter Blade Designs on Sugarcane Stem Cut Quality." Transactions of the ASABE 60, no. 5 (2017): 1551–60. http://dx.doi.org/10.13031/trans.12345.
Full textAbstract:
Abstract. The cut quality of sugarcane stems during harvesting is of considerable importance, as any damage inflicted on the stems and root systems affects ratooning and reduces yield. In current conventional cutting systems for sugarcane, relatively little attention has been paid to optimizing the cutting dynamics by investigating various blade designs and configurations. One limitation of impact cutting methods is the relatively rapid blunting of the blade edges through wear, leading to stem damage. This study aimed at investigating the effects on sugarcane cut quality of four base cutter blade designs: a conventional straight blade, a 30° angled blade, a serrated blade, and a straight blade with laser cladding on its underside. Blades of each type were installed at a 45° angle on a base cutter fitted to a John Deere 3520 sugarcane harvester. Stem damage, root system damage, and stubble height were considered as cut quality indicators, and blade wear was evaluated as the percentage of metal mass loss after completing each harvesting operation. In this study, the extent of stem and root system damage was classified into nine categories: (1) undamaged stem, not uprooted, (2) undamaged stem, partially uprooted, (3) undamaged stem, uprooted, (4) partially damaged stem, not uprooted, (5) partially damaged stem, partially uprooted, (6) partially damaged stem, uprooted, (7) severely damaged stem, not uprooted, (8) severely damaged stem, partially uprooted, and (9) severely damaged stem, uprooted. The highest percentage of stems damaged during harvesting (approx. 38%) and the highest percentage of root systems damaged (approx. 36%) occurred with the angled blade. The percentages of undamaged stems for the straight, angled, serrated, and laser clad blades were 76.9%, 62.1%, 83.1%, and 72.3%, respectively; partially damaged stems were 11.25%, 21.97%, 11.29%, and 17.73%, respectively; and severely damaged stems were 11.9%, 15.9%, 5.65%, and 9.9%, respectively. Except for the angled blade, all the blades cut almost 80% of stems without affecting the root system, and only 5% of stems were uprooted. Indices for stem damage and uprooting damage were calculated to evaluate the cut quality on a scale from -1.00 (least damage) to +1.00 (greatest damage). For both indices, the serrated blade had values closest to the target value of -1.00, implying the least damage to stems and root systems. Greater stubble heights (110 mm) were observed for the angled blade, with 76% of cut stems above the target 75 mm threshold, which was selected based on the farmer’s suggestion. Comparatively less stubble height was obtained with the serrated and laser clad blades, and roughly 60% of stems were cut in the ideal range (<75 mm). Blade wear percentages per ha of harvested area, based on metal mass loss, were found to be 0.76% for the laser clad blade, 0.83% for the serrated blade, and 0.84% for the straight blade. No mass loss data were collected for the angled blade as it caused such a high level of stem damage that its test was discontinued. The results of this study classified the levels of stem and root system damage occurring in the field during harvesting and their effects on ratooning for four base cutter blade designs. Fundamental guidelines for optimal blade configurations associated with sugarcane harvesting are provided. Keywords: Blade wear, Stem damage, Stubble height, Sugarcane harvester.
8
Maskur, Atep, M. Agung Wibowo, and Setya Winarno. "Damage Assessment Method for Light Steel Roof Frames: Case Study of Government Buildings." Semesta Teknika 27, no. 1 (2024): 10–20. http://dx.doi.org/10.18196/st.v27i1.18341.
Full textAbstract:
The tornado disaster in Ciamis Regency damaged 55 buildings, including the Panawangan District Office. The aim of this research was to identify the condition and level of damage to the Light Steel Roof Frame Structures that were damaged and determine the ranking or percentage of damage. By making direct observations at the location of the incident. The result is that: The roof covering element uses zincalum metal with the batten frame partially damaged on the left side of the building above the hall and the right corner of the front of the building. The battom chord, top chord and web elements are partially detached. The trim element made of GRC material is damaged. came loose, and the Gypsum ceiling elements with hollow frames fell on the outside and inside the hall. The percentage of damage obtained is 14.50% and the damage level ≤ 30% is categorized as Light Damage.
9
L.C.P. Fernando. "Effect of Application Frequency of the Entomopathogenic Fungus Hirsutellathompsonii (Fisher) on Damage Levels of Coconut Mite Aceriaguerreronis (Keifer)." CORD 27, no. 2 (2011): 8. http://dx.doi.org/10.37833/cord.v27i2.115.
Full textAbstract:
The effect of application interval of H. thompsonii (Fisher) on damage caused by the coconut mite, Aceriaguerreronis (Keifer) (Acari: Eriophyidae) in two coconut plantations in Sri Lanka was evaluated. In each plantation, coconut palms infested by coconut mite were treated with H. thompsonii isolate IMI 391722 at 2- and 3-monthly intervals and the fruits with H. thompsonii-infected coconut mite cadavers and percentage of harvested fruits in different damage categories were assessed. Infected coconut mite cadavers were found on up to 60% of the fruits treated with the fungus in both plantations at treatment frequencies. The effect of the treatments was site-specific. The treatments reduced the percentage of damaged-small size harvested fruits to half that of the untreated control in both plantations irrespective of the frequency of treatment. At one plantation, the percentages of undamaged fruits and fruits with discontinued damage were nearly doubled to that of untreated fruits.
10
Umeh, V. C., F. Waliyar, and A. Traoré. "Aspergillus Species Colonization of Termite-Damaged Peanuts in Parts of West Africa and Its Control Prospects." Peanut Science 27, no. 1 (2000): 1–6. http://dx.doi.org/10.3146/i0095-3679-27-1-1.
Full textAbstract:
Abstract A survey of farmers' peanut fields in Benin showed that Aspergillus flavus Link ex Fries infection was influenced by Microtermes (Isoptera: Termitidae) damage. Field trials conducted at the ICRISAT station and a farmer's plot in Mali on termite damage and Aspergillus spp. infection showed that peanut plots treated with carbofuran at planting and supplemented with chlorpyrifos at 40 days after planting (dap), or treated with only chlorpyrifos at 40 dap, significantly reduced pod damage by the termite M. lepidus Sjöstedt. and colonization by A. flavus. The cultivar ICG 10946 which had significantly more A. flavus (P < 0.05) also had a higher percentage of damaged pods compared with the other cultivars at the on-station trials. The least infected cultivar in all the trials was 47–16 which also had a comparatively lower percentage of termite-damaged pods, although this was not significant. However, termite damage was correlated with A. flavus percentage colonization.
Dissertations / Theses on the topic "Damage Percentage"
1
Wong, Alvaro Yat Set. "´´Evaluación de la compatibilidad de tinciones no fluorescentes de Diffquik, Giemsa, Fastblast y de Feulgen con el Bioensayo Cometa en el ADN espermático humano´´." Bachelor's thesis, Universidad Ricardo Palma, 2016. http://cybertesis.urp.edu.pe/handle/urp/826.
Full textAbstract:
La fertilidad masculina puede ser medida mediante un espermatograma convencional, sin embargo este examen no incluye la valoración de la integridad del ADN espermático. Esta variable ha sido correlacionada con las tasas de fertilización, viabilidad y desarrollo del embrión, convirtiéndose en una herramienta de importancia clínica tanto para los programas de reproducción animal como los tratamientos de fertilidad asistida.
El bioensayo Cometa es capaz de determinar de una manera exacta el valor de la integridad del ADN espermático, lamentablemente este examen no es de uso rutinario por su elevado costo de implementación ya que utiliza microscopia especializada y tinciones fluorescentes para evidenciar la migración del ADN.
El objetivo de esta investigación fue evaluar la compatibilidad de las tinciones no fluorescentes Diffquik, Giemsa, de Feulgen y FastBlast en el bioensayo Cometa usando un método visual y automatizado. Se utilizaron 15 eyaculados previamente seleccionados de acuerdo al manual OMS 2010, para luego ser capacitados en búsqueda de homogeneidad adecuada para la experimentación. Cada muestra fue expuesta a una gradiente de Peróxido de hidrogeno (0, 10, 30,60 y 100 mM) por 1 hora a 4°C para luego evaluar el coeficiente de daño mediante el método visual y porcentaje de ADN en la cola mediante el método automatizado.
Las pendientes de la regresión lineal en el método visual indican que los valores obtenidos por la tinción control SybrGreen (m=3,69) difieren con Giemsa (m=3,45) y Diffquik (m=2,57). En el método automatizado de igual manera SybrGreen (m=0.83), Giemsa (m=0,79) y Diffquik (m=0,77).
Sin embargo SybrGreen es 1,06 veces más efectivo que Giemsa en el visual y 1,05 veces en el automatizado, sugiriendo una compatibilidad con el bioensayo cometa. De igual manera SybrGreen es 1,07 veces más efectivo que Diffquik en el visual y 1,44 veces en el automatizado, concluyendo una compatibilidad solo en el método visual.Male fertility can be measured by a conventional semen analysis, however, this examination does not include the assessment of sperm DNA integrity. This variable has been correlated with fertilization rates, embryo viability and development, becoming a tool of clinical importance for both animal breeding programs and assisted fertility treatments.
Comet bioassay is able to determine an exact way the value of sperm DNA integrity, unfortunately this test is not routinely used because of its high cost of implementation because it uses specialized microscopy and fluorescent dyes to demonstrate DNA migration.
The objective of this research was to evaluate the compatibility of non-fluorescent dyes Diffquik, Giemsa, Feulgen and Comet FastBlast in the bioassay using a visual and automated method. 15 ejaculates were used previously manually selected according to WHO 2010 and then be trained in finding adequate homogeneity for experimentation. Each sample was exposed to a hydrogen peroxide gradient (0, 10, 30,60 and 100 mM) for 1 hour at 4 ° C and then assess the damage coefficient by visual method and percentage of DNA in the tail by automated method.
The slopes of the linear regressions on the visual method indicate that the values obtained by the SybrGreen Control staining (m = 3.69) differ with Giemsa (m = 3.45) and Diffquik (m = 2.57). In the same way automated method SybrGreen (m = 0.83), Giemsa (m = 0.79) and Diffquik (m = 0.77).
However SybrGreen is 1.06 times more effective than Giemsa visual and 1.05 times in the automated, suggesting a comet support bioassay. Similarly SybrGreen is 1.07 times more effective than Diffquik visual and 1.44 times in the automated, concluding compatibility only in the visual method.
Keywords:
2
Wu, Chi-Jung, and 吳啟榮. "The study of Improving the Damage Percentage of Gold Wire in the Molded VFBGA Chips using the Taguchi Method." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/20370878540285043746.
Full textAbstract:
碩士<br>國立屏東科技大學<br>機械工程系所<br>100<br>This study focuses on investigating the reduction of gold-wire damage in an existing process of very fine pitch ball grid array (VFBGA) transfer molding. Using analysis of mean (ANOM) of the Taguchi method, the optimum conditions for molding VFBGA microelectronic assembly with very minimal wire damage were obtained. These optimum conditions included: (1) a substrate preheat temperature of 177 , (2) a two-step mold clamping [the first-stage adapted clamp force (9 ton) and a second-stage full clamp force (28 Ton)], (3) a mold temperature of 180 , and (4) a bottom mold vacuum hole number of 20.
Under these optimum conditions, a confirmation experiment was carried out, and the average defect percentage of the wire damage decreased to 0.02%. The percentage contribution of each controllable factor within the current investigation range was also determined via ANOVA (analysis of variance) of the Taguchi method. Among the four controllable factors, the number of vacuum hole in a bottom mold was the most influential on the wire damage; its percentage contribution was 72.14% and the mechanism of wire damage due to insufficient vacuum hole was also presented. Through a modification of the existing process of VFBGA transfer molding according to the optimum conditions, its maximum defect percentage of wire damage per sub lot substantially decreased to 0.12% from 1.31% (before modification), and its average defect percentage of wire damage for 14 sub lots decreased to 0.03% from 1.10%.
Books on the topic "Damage Percentage"
1
Leite, Leonardo Canez. Direito e pesquisa: Um dossiê de artigos científicos - Volume 2. Brazil Publishing, 2021. http://dx.doi.org/10.31012/978-65-5861-230-8.
Full textAbstract:
Essential to the administration of justice, the lawyer plays a key role in postulating a decision favorable to his constituent and convincing the judge. However, it is common in nature to the formation and performance of bad professionals, who, due to their inconsistent actions or omissions, cause damage, whether material or moral, in the face of claims to be reached by their contractors, forming in the popular imagination a pejorative stereotype regarding the performance. from the lawyer. However, it is part of this area, a very small percentage that denigrate the image of valuable operators of the law. Thus, the Civil Liability of the Lawyer before the Theory of the Loss of a Chance becomes possible, because through misery, lack of knowledge, among others, according to the Brazilian Bar Association, lead the professional services contractor. attorneys to suffer direct or indirect damages, as they see the possibility of obtaining any economic advantage or avoid an injury, given the lost chance. Thus, even if the damage is uncertain, but if concrete probabilities are present, it should be compensated, not for the unwanted end result, but for the mere loss of the chance of achieving it.
2
Banerjee, Shyamli. Intimal damage and thrombosis in microvascular surgery: An experimental and scanning electron microscopic study ofthe effect of damaging the intima of 1mm diameter vessels and the percentage patencyrate under different treatments. 1985.
Find full text
3
Yousuf, Muhammad Saad, and Bradley J. Kerr. The challenges of animal models of pain. Edited by Paul Farquhar-Smith, Pierre Beaulieu, and Sian Jagger. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780198834359.003.0036.
Full textAbstract:
The landmark paper discussed in this chapter is ‘Animal models of pain: progress and challenges’, published in the journal Nature Reviews Neuroscience by Jeff Mogil of McGill University in 2009. The most common symptom across various medical conditions and a major reason for seeking physician consultation is pain. It is defined as ‘an unpleasant feeling or emotional experience associated with actual or potential tissue damage’. A large percentage of the research investigating the biological mechanisms of pain is performed on animals. Human studies of pain are limited by lack of practicality, subjectivity, and ethical considerations. This influential review by Mogil discusses the progress and challenges faced in studying pain using various animal models.
4
Galderisi, Maurizio, Juan Carlos Plana, Thor Edvardsen, Vitantonio Di Bello, and Patrizio Lancellotti. Cardiac oncology. Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780198726012.003.0064.
Full textAbstract:
Cancer therapeutics may induce cardiac damage in the left and the right ventricle. Radiotherapy most frequently induces valvular damage, carotid stenosis, and coronary artery disease. Pericardial disease may be due to both chemo- and radiotherapy. The manifestations of both chemo- and radiotherapy can develop acutely but also become overt years after their performance, in particular after radiotherapy. The main cardiac damage of cancer therapeutics-related cardiac dysfunction (CTRCD) corresponds to the reduction of left ventricular (LV) systolic function. The Expert Consensus document from ASE and EACVI has defined CTRCD as a decrease in LV ejection fraction (LVEF) of greater than 10 percentage points, to a value less than 53%. The accurate calculation of LVEF at baseline and during follow-up is extremely important. The assessment of LV longitudinal function, in particular of speckle tracking-derived global longitudinal strain (GLS), can provide additional information, allowing early, subclinical detection of CTRCD. The ideal strategy could be to compare the measurements of GLS obtained during chemotherapy, with the one obtained at baseline. An integrated approach with the use of echocardiography at standardized, clinical preselected intervals with biomarker (ultrasensitive troponin) assessment prior to each chemotherapy cycle could be suggested in patients at high risk of CTRCD. Follow-up after therapy should depend on the type of chemotherapy/radiotherapy and the presence/absence of on-therapy CTRCD. Long-term follow-up should be planned after radiotherapy.
5
Stańczykiewicz, Arkadiusz. Prawdopodobieństwo wystąpienia szkód w odnowieniach podokapowych wskutek pozyskiwania drewna oraz model ich szacowania. Publishing House of the University of Agriculture in Krakow, 2018. http://dx.doi.org/10.15576/978-83-66602-34-2.
Full textAbstract:
An analysis of the existing literature on the issue of damage to regeneration caused by timber harvesting, revealed that a great majority of results reported in those publications was obtained through laborious and time-consuming field research conducted in two stages. Field research methods for gathering data, employed by various authors, differed in terms of the manner of establishing trial plots, the accuracy of counting and evaluating the number of saplings growing on the investigated sites, classification systems used for distinguishing particular groups of regeneration based on quantitative (diameter at breast height, tree height) and qualitative features (biosocial position within the certain layer and the entire stand), classification systems used for identifying types of damage caused by cutting and felling, as well as transporting operations, and finally the duration of observation intervals and time spent on gathering data on the response of damaged saplings from both, the individual and collective perspectives. Obviously, the most reliable manner of gathering such data would be to count all damaged elements of the environment being a subject of interest of particular investigators at the certain point of time. However, due to time and work consumption of this approach, which is besides very costly, any research should be designed in such a manner as to reduce the above-mentioned factors. This paper aimed to (1) analyse the probability of occurrence of damage to regeneration depending on the form of timber assortments dragged from the felling site to the skidding routes, and timber harvesting technology employed in logging works, and (2) identify a method ensuring that gathered data is sufficient for performing reliable evaluation of share of damage to regeneration at acceptable accuracy level, without necessity to establish trial plots before commencing harvesting works. The scope of these studies enclosed a comparison between two motor-manual methods of timber harvesting in thinned stands, with dragging of timber in the first stage of skidding from the stand to landings. According to one of these methods, a classical one, operations of felling and delimbing of trees were carried out by sawmen at the felling site. Timber obtained using different methods was skidded by carters and horses, and operators of a light-duty cable winch, driven by the chainsaw’s engine, as well as operators of cable winches combined with farm tractors. In the latter, alternative method, sawmen performed only cutting and felling of trees. Delimbing and cross-cutting of trunks, dragged from the felling sites, was carried out by operators of processors combined with farm tractors, worked on skidding routes. The research was conducted in the years 2002–2010 in stands within the age classes II–IV mostly, located in the territories of Regional Directorates of State Forests in Krakow and Katowice, and in the Forest Experimental Unit in Krynica-Zdrój. In the course of a preliminary stage of investigations 102 trial plots were established in stands within early and late tinning treatments. As a result of the field research carried out in two stages, more than 3.25 thsd. circular sites were established and marked, on the surface of which over 25 thsd. saplings constituting the regeneration layer were inventoried. Based on the results of investigations and analyses it was revealed that regardless of the category of thinning treatment, the highest probability of occurrence of destroying P(ZN) to regeneration (0.24–0.44) should be expected when the first stage of timber skidding is performed using cable winches. Slightly lower values of probability (0.17–0.33) should be expected in stands where timber is skidded by horses, while in respect to processor-based skidding technology the probability of destroying occurrence oscillates between 0.12 and 0.27, depending on the particular layer of regeneration. P(ZN) values, very close to those of skidding technology engaging processors, were recorded for skidding performed using the light-duty cable winch driven by the chainsaw’s engine (0.16–0.27). The highest probability of damage P(USZK) to regeneration (0.16–0.31) can be expected when processors are used in the first stage of timber skidding. Slightly lower values of probability (0.14–0.23) were obtained when skidding was performed with the use of cable winches, whereas engaging horses for hauling of trunks results in probability of damage occnrrence oscillating between 0.05–0.20, depending on the particular layer of regeneration. With regard to the probability of occurrence of both, destroying and damage P(ZNUSZK) to regeneration (0.33–0.54), the highest values can be expected when cable winches are engaged in the first stage of skidding. Little lower (0.30–0.43) was the probability of their occurrence if processor-based technology of skidding was employed, while in respect to horse skidding these values oscillated between 0.27–0.41, depending on the layer of regeneration. The lowest values of probability of occurrence of damage P(USZK), and destroying and damage treated collectively P(ZNUSZK), within all layers of regeneration, were recorded in stands where thinning treatments were performed using the light-duty cable winch driven by the chainsaw’s engine. The models evaluated and respective equations, developed based on those models, for evaluating the number of destroyed saplings ZNha (tab. 40, 42, 44, 46, 48) could be used for determining the share of damage expressed as a percentage, upon conducting only one field research at the investigated felling sites, once the timber harvesting and skidding would have been completed. As revealed by the results of analyses, evaluation of statistically significant regression models was possible for all layers of regeneration (tab. 39, 41, 43, 45, 47). Nevertheless, the smallest part of these models that could be considered positively verified, were those for the natural young regeneration, although almost a half of them revealed to be significant. Within the medium-sized regeneration over three-fourths of all models could be considered positively verified, four of which explained more than 50% of variability. Within the high-sized regeneration almost two-thirds of evaluated regression models were statistically significant, five of which were verified positively, moreover, one of them explained more than 50% of variability. The most promising results were those obtained for the advance growth. Nearly 90% of the evaluated models revealed to be statistically significant, ten of which could be considered positively verified. Furthermore, four statistically significant models explained over 50% of general variability. With regard to the entire regeneration more than 80% of evaluated models were statistically significant. However, due to insignificant coefficients of regression, eight of them could be considered positively verified. At this point it should be stressed that in respect to logging technology employing the light-duty cable winch FKS it was impossible to evaluate statistically significant models of regression. Whereas, in the case of processor-based logging technology, firstly regarding the advance growth, and then the entire regeneration, all of the evaluated statistically significant models could be considered positively verified, in terms of both, all of the stands, and particular categories of thinning treatments individually. This latter case also revealed the highest degree of matching of evaluated models (R2 popr 0.73–0.76 for advance growth and 0.78–0.94 for the entire regeneration). A significant impact of the kind of form of hauled timber on the probability of damage occurrence P(USZK), mainly in early thinning treatments, could have been reflected in the results obtained for all stands (early and late thinning treated collectively). Moreover, due to an insignificant impact of the form of hauled timber and logging technology employed, on the probability of occurrence of damage in late thinned stands, and a significant impact of the above-mentioned variables on early thinned stands, it should be assumed that for performing an evaluation of destroying and damage caused by timber harvesting the both thinning treatment categories should be analysed separately. Furthermore, when evaluating the probability of occurrence of destroying and damage caused by timber harvesting, the layers of natural young regeneration and advance growth should be analysed separately. As proved by the results presented in this paper, varying values of probability computed for each of the layers of regeneration seem to indicate that when investigating damage to regeneration caused by timber harvesting, it would be reasonable and recommended to perform a separate analysis of damage to the highest saplings as well, namely individuals with diameter at breast height close to 7 cm. In respect to studies on damage to regeneration caused by logging technologies mentioned above, the evaluation of number of destroyed saplings within the advance growth can be carried out using the proportions of damaged and undamaged saplings per 1 ha of the stand. The numbers evaluated in this manner can be used to calculate the damage share expressed in relative values (percentage of damaged saplings compared with the entire number of saplings before commencing the logging works). However, one should keep in mind that this is true only if the field research have been carried out based on the methodology described in this paper.
Book chapters on the topic "Damage Percentage"
1
Yi, Cheng, Shi Zhao Shen, He Ping Xie, and Chang Jun Wang. "Flexural Fatigue Damage Evolution for Partially High Percentage Fiber Reinforced Concrete." In Fracture and Damage Mechanics V. Trans Tech Publications Ltd., 2006. http://dx.doi.org/10.4028/0-87849-413-8.827.
Full text
2
Oulad Brahim, Abdelmoumin, Roberto Capozucca, Erica Magagnini, Bochra Khatir, and Abdelwahhab Khatir. "Predict Damage Percentage in Test Specimens Using Improved Artificial Neural Network." In Lecture Notes in Civil Engineering. Springer Nature Switzerland, 2024. http://dx.doi.org/10.1007/978-3-031-57224-1_11.
Full text
3
Fenwick, Alan, Wendie Norris, and Becky McCall. "Advocacy and promotion of SCI activity." In A tale of a man, a worm and a snail: the schistosomiasis control initiative. CABI, 2021. http://dx.doi.org/10.1079/9781786392558.0013.
Full textAbstract:
Abstract Not all cases are extreme, but only a small percentage of the estimate 200 million people infected with schistosomiasis in Africa suffer this fate. Schistosomiasis eggs accumulate and damage organs slowly, day after day, without their function being impaired, up until it's too late. Usually, it is only then that symptoms become apparent and schistosomiasis is diagnosed. This book chapter focuses on campaigns focused on schistosomiasis control and prevention.
4
Salinas Ruíz, Josafhat, Osval Antonio Montesinos López, Gabriela Hernández Ramírez, and Jose Crossa Hiriart. "Generalized Linear Mixed Models for Proportions and Percentages." In Generalized Linear Mixed Models with Applications in Agriculture and Biology. Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-32800-8_6.
Full textAbstract:
AbstractIn this chapter, we will review generalized linear mixed models (GLMMs) whose response can be either a proportion or a percentage. For proportion and percentage data, we refer to data whose expected value is between 0 and 1 or between 0 and 100. For the remainder of this book, we will refer to this type of data only in terms of proportion, knowing that it is possible to change it to a percentage scale only when multiplying it by 100. Proportions can be classified into two types: discrete and continuous. Discrete proportions arise when the unit of observation consists of N distinct entities, of which individuals have the attribute of interest “y. ”N must be a nonnegative integer and “y” must be a positive integer; here, y ≤ N. Therefore, the observed proportion must be a discrete fraction, which can take values $$ \frac{0}{N},\frac{1}{N},\cdots, \frac{N}{N} $$ 0 N , 1 N , ⋯ , N N . A binomial distribution is the sum of a series of m independent binary trials (i.e., trials with only two possible outcomes: success or failure), where all trials have the same probability of success. For binary and binomial distributions, the target of inference is the value of the parameter such that $$ 0\le E\left(\frac{y}{N}\right)=\pi \le 1 $$ 0 ≤ E y N = π ≤ 1 . Continuous proportions (ratios) arise when the researcher measures responses such as the fraction of the area of a leaf infested with a fungus, the proportion of damaged cloth in a square meter, the fraction of a contaminated area, and so on. As with the binomial parameter π, the continuous rates (fractions) take values between 0 and 1, but, unlike the binomial, the continuous proportions do not result from a set of Bernoulli tests. Instead, the beta distribution is most often used when the response variable is in continuous proportions. In the following sections, we will first address issues in modeling when we have binary and binomial data. When the response variable is binomial, we have the option of using a linearization method (pseudo-likelihood (PL)) or the Laplace or quadrature integral approximation (Stroup 2012).
5
Battaglia, Fabio-Massimo. "Climate Change and the Ocean: The Disruption of the Coral Reef." In Sustainable Development Goals Series. Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-24888-7_10.
Full textAbstract:
AbstractEven though coral reefs represent a negligible percentage of the ocean floor, they are wardens of incredible biodiversity. They provide support for at least 500 million people with food security and livelihoods, mostly in poor or developing countries.Despite their importance, coral reefs are also extremely fragile. They are among the most damaged and threatened ecosystem due to unprecedented global warming, ocean acidification and climate changes, combined with increasing local pressures. These incredible ecosystems are calling us into action towards more efficient protection to ensure their conservation and restoration.
6
Blandino, Amalia, Gabriele Carapezza Figlia, Letizia Coppo, Snežana Dabić Nikićević, and Katarina Dolović Bojić. "Gender Equality in the Different Fields of Private Law." In Gender-Competent Legal Education. Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-14360-1_15.
Full textAbstract:
AbstractIn the field of private law, gender inequality takes many different shapes. It may at times be easily noticed from the text of the legal rules, for instance, when certain legal rights are reserved for members of a certain gender (i.e. independency to enter a marriage) or when they are available to both genders but in a discriminatory manner (i.e. men inherit twice as much as women). However, in many legal systems equality is guaranteed by law, but inequality still appears in practice. This may be seen from the fact that, on average, land assets are much more often owned by men or that a higher percentage of men run a business. Various social factors may induce gender inequality, like stereotypical division of gender roles in society (i.e. men as breadwinners and women as caregivers) or the persistence of patriarchal customs and practices (i.e. women should renounce their inheritance rights in favour of male inheritors). The consequences of such factors may also be felt in the field of tort law, especially when it comes to damages suffered by women performing unpaid domestic work or indirect damages suffered by women who have to provide the “informal support” for the person who suffered serious bodily harm that resulted in a situation of dependency. Finally, in the field of contract law, the most difficult tasks seem to be to reconcile the prohibition of discrimination with the freedom of contract and to determine the most suitable legal consequence in case of discrimination.
7
Wang, Yong, Chen Xu, Changchun Li, Xiaofei Yao, Xingbo Xiang, and Haoxuan Huang. "Surface Vibration of Throw-Type Blast in an Open-Pit Mine." In Lecture Notes in Civil Engineering. Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-99-2532-2_11.
Full textAbstract:
AbstractIn the process of Open-pit mining in China, throwing blasting is an important method, which is very likely to cause serious damage to the slope of the discharge field under the action of vibration load of throwing blasting. With the background of throwing blasting process in Heidaigou open-pit mine in Ordos, vibration velocity data were collected from the discharge field near the throwing blast, and the vibration signal of throwing blast was analyzed by means of Fourier transform to obtain the characteristics of throwing blast vibration velocity wave and the attenuation law and prediction formula in the process of propagation. The results show that: 100 ~ 300 m away from the blasting area, the radial direction (X direction) of the blasting area produces the largest vibration velocity of 26.8 cm/s, but at the same time, the decay rate of the peak vibration velocity of the survey line 2 in each direction is small, and the decay percentages of 56, 75 and 70% are smaller than that of the survey line 1 and survey line 3 in the lateral direction of the blasting area, and the decay rate of the velocity is smaller as the propagation As the distance increases, the decay rate of the velocity decreases. The curve gradually tends to flatten and the vibration velocity of the three directions gradually close. The frequency band of the blast vibration is distributed within 200 Hz and the frequency and energy are mainly distributed in the low frequency stage (0–20 Hz), accounting for more than 50% of the total energy.
8
Fattah, Abdul, Idaryani Djamaluddin, Asriyanti Ilyas, Muslimin Muslimin, Andi Nurhayu, and dan Muhammad Yasin. "Symptoms of Damage to Soybean Varieties Due to Major Pest Attacks in South Sulawesi, Indonesia." In Legumes [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.101263.
Full textAbstract:
South Sulawesi Province is one of the centers for soybean development in Indonesia. The varieties that are widely planted by farmers in South Sulawesi include Anjasmoro, Argomulyo, Grobogan, Gema, Dering-1, and Burangrang. These varieties have different levels of seed yield and damage levels. This paper aims to provide an overview and information about the types of soybean varieties, the level of pest damage, and the types of pests that cause damage to soybean varieties developed by farmers in South Sulawesi Province. The method used is to collect various information in the form of secondary data and primary data from research results related to soybean varieties, types of pests that damage soybean plants and the level of damage caused by soybean pests in South Sulawes. The results obtained provide information that the highest level of leaf damage caused by Spodoptera litura F. occurred in the Anjasmoro variety 10.94–32.69% followed by Argomulyo 10.16–26.17% and Grobogan 8.61–24.81%. The highest level of pod damage due to pod sucking was found in Burangrang varieties, namely 13.20%, Gema 12.51%, Dering 10.5%, Argomulyo 9.40%, Grobogan 8.50%, and Anjasmoro 7.70%. The level of fruit damage caused by the fruit borer Etiella zinckenella T., the highest occurred in Detam-1 15.71%, Ring 14.50%, Burangrang 10.60%, Gema 10.0%, Argomulyo 8.20%, Grobogan 7.10%, and Anjasmoro 6.70%. The rate of soybean yield loss caused by S. litura F. was the highest at Anjasmoro 8.97%–11.29%, then Grobogan 7.88–12.80%, and Argomulyo 6.77–14.90%. Meanwhile, the percentage of seed yield loss caused by the attack of the pest Nezara viridula L. ranged from 10.0–41.0% for all varieties. Likewise with Riptortus linearis F., the percentage of soybean seed loss caused ranged from 15 to 79% for all varieties.
9
Imane Beloufa, Hadja, Mostapha Tarfaoui, Khalid Lafdi, Mohamed Daly, and Amine Bendarma. "Graphene Sheets as Novel Nanofillers in Epoxy Matrix for Improved Mechanical Properties." In Advances in Nanosheets [Working Title]. IntechOpen, 2023. http://dx.doi.org/10.5772/intechopen.1001834.
Full textAbstract:
In this paper, we will be interested in bending tests on a polymer matrix reinforced with graphene nanofillers. The mechanical behaviour and the damage kinetics were determined. The samples were made using controlled dispersions of graphene nanoplatelets (GNP) in EPON 862 matrix. Various samples with different contents of GNP were made (0%, 0.5%, 1%, 2.5%, 5% and 10% by weight). Mechanical properties such as maximum stress, strain at break and Young's modulus were determined. After each test, the fracture surfaces were characterised using optical microscopy (OP) and scanning electron microscopy (SEM). Experimental results show that the fracture toughness of the GNP/epoxy-based nanocomposites decreases with an increasing percentage of nanofillers. The flexural strength of the samples with 10 wt% of graphene significantly decreased compared to neat epoxy. Based on Stress-Strain data and the analysis of the fracture surface, it seems that graphene nanoplatelets show an impact on the mechanical behaviour and the kinetics of the damage. The influences of the weight percentage of GNP on the EPON matrix properties and the performance of the nanocomposites are discussed. In addition, the evolution of bending performance and damage kinetics with graphene content was obtained and analysed.
10
Fornari, Victoria, Ana Fajreldines, and Marcelo Pellizzari. "Analysis of the Behavior of Plasma Concentrations of Tacrolimus in Adult Patients with Liver Transplantation: Adverse Reactions and Drug Interactions and Their Relevance to Patient Safety." In Controversies in Liver Transplantation - Recent Challenges and Future Perspectives. IntechOpen, 2023. http://dx.doi.org/10.5772/intechopen.107994.
Full textAbstract:
Organ transplantation is a medical treatment often used to restore the function of vital organs. Tacrolimus is one of the most widely used drugs in the immunosuppressive treatment of liver transplants. Aims: To analyze plasma concentrations of tacrolimus in adult liver transplant patients and to characterize adverse effects and drug interactions. Design: retrospective observational studies. The study included 32 patients, of whom 22 were male and 10 female. The average values and range of tacrolimus obtained showed a mean of 8.7 SD 3.2. Low values were found in seventy-five cases, with a percentage of 54.8%. The values within the expected had a frequency of fifty-three times with a percentage of 38.7%. Finally, the frequency of high values was nine times with a percentage of 6.5%. A total of 36 RAM types were found. It was determined that the majority of the ADRs were of moderate damage (13) of 46.4%, while 39.3% of the ADRs were of slight damage (11), 14.3% were of severe damage (4) and no ADR was incidental. Clinically relevant drug interactions in this group of patients were 16.7% contraindicated, 16.7% adjustments based on close follow-up, and 66.6% use with routine follow-up. Similar to the interactions present in the 2013 EMA data sheet. Plasma tacrolimus concentrations are within the range of 38.7% in male patients and 40.8% in female patients. 61.3% of male patients and 59.2% of female patients do not reach the expected tacrolimus plasma levels of 8.0−11.0 ng/ml, similar to those presented in the 2009 FDA data sheet. There were 220 ADRs in this sample of 32 liver transplant patients.
Conference papers on the topic "Damage Percentage"
1
Gummow, R. A., S. M. Segall, and R. G. Wakelin. "Coating Quality Testing of Directionally Drilled Pipe Sections." In CORROSION 2000. NACE International, 2000. https://doi.org/10.5006/c2000-00764.
Full textAbstract:
Abstract Methods of determining the coating quality on directionally drilled pipe sections were investigated in a research project sponsored by the Pipeline Research Committee of the American Gas Association. Tests were conducted on FBE coated pipe samples which were buried in three different soil conditions and equipped with steel strip coupons to simulate coating damage. A field test procedure, which can be performed by a CP technician, was developed that estimates coating quality in terms of percentage bare.
2
Paterlini, Luca, Luca Casanova, Giorgio Re, Marco Ormellese, and Fabio Bolzoni. "A Comparison among Different Electrochemical Hydrogen Charging Methods Tested on Low Alloy Steels." In CONFERENCE 2023. AMPP, 2023. https://doi.org/10.5006/c2023-18866.
Full textAbstract:
Abstract The current energy demand and the need to contain carbon dioxide emissions require the adoption of new energy vectors. Based on that, a progressively increasing percentage of gaseous hydrogen will be filled inside natural gas transportation pipeline systems, thus requiring a rigorous material compatibility assessment. It is well known how carbon and low alloy steels, may suffer hydrogen damage and hydrogen embrittlement, resulting in the reduction of toughness and ductility. The present study has been carried out in order to compare three different electrochemical methods to charge H into low-alloy steels (ASTM A 182 F22 and AISI 4140) samples presenting typical dimensions used for fracture mechanics tests. The study of the effect of different H recombination poisoners indicated As2O3 as the preferable choice in terms of H content and reproducibility.
3
Al-Luqman, Salah, Iyad Al-Buraiki, and Majed M. Al-Qarni. "Corrosion Mitigation and Monitoring in Sulfur Recovery Units." In CORROSION 2009. NACE International, 2009. https://doi.org/10.5006/c2009-09358.
Full textAbstract:
Abstract The main objective of Sulfur Recovery Units (SRU) is to remove sulfur compounds (mainly hydrogen sulfide) from gases produced by sweetening of refinery or sour field production gases. The sulfur compounds are converted to elemental sulfur, and then the sulfur is condensed to liquid sulfur. The feed contains mainly hydrogen sulfides coming from amine and sour water units. Corrosion is a major concern in SRUs due to the presence of a high percentage of hydrogen sulfide, as well as high temperatures in most of the unit’s equipment. This paper will demonstrate the fundamental corrosion issues encountered in SRUs. In addition, it will address the Claus process chronic corrosion problems such as sulfidation, sour environment cracking, weak acid corrosion, and other damage mechanisms. Moreover, it will propose protective actions and applicable corrosion monitoring techniques to avoid reoccurrence of corrosion problems.
4
Franke, Florian, Sebastian Heimbs, Christian Seidel, Patrik-Vincent Brudzinski, Dominic Huehn, and Uli Burger. "High Speed Impact Testing of Thermoplastic Composite Plates." In Vertical Flight Society 73rd Annual Forum & Technology Display. The Vertical Flight Society, 2017. http://dx.doi.org/10.4050/f-0073-2017-12166.
Full textAbstract:
This paper presents the methodology and results for ballistic impact testing of thermoplastic composite materials. Ten different materials are investigated. The impact behavior of Aluminum 6082 is used as a reference to compare the results. The impact tests are performed with a gas cannon. Force - time, displacement - time as well as velocity data are recorded. Analytic suggestions for the calculation of the penetration speed of the materials are compared with measured results. It can be seen that it is possible to calculate the penetration speed within a certain percentage of the measured value. Also, the absorbed energies during the penetration process are compared. The results show that glass fiber composites have a better impact material behavior than carbon fiber-reinforced composites (CFRP). Thermoplastic matrix systems are a cheap option for composites but they do not have a significant better high speed impact and damage behavior than duroplastic resins.
5
Sui, Pengfei, Jianbo Sun, Chong Sun, Yong Wang, and Yong Hua. "The Influence of Flow Rate on Corrosion Behavior of X65 Carbon Steel in Water-saturated Supercritical CO2/H2S System." In CORROSION 2019. NACE International, 2019. https://doi.org/10.5006/c2019-13081.
Full textAbstract:
Abstract The influence of flow rate on corrosion behavior of X65 carbon steel in water-saturated supercritical CO2 phase containing 1000 ppmv H2S impurity was studied at 35 °C and 8 MPa from 0 m/s to 1.5 m/s. Weight loss tests showed that the general corrosion rate reached maximum at the flow rate of 1 m/s and then decreased with flow rate to 1.5 m/s. Turtle pattern corrosion morphology was observed on the sample surface when the flow rate exceeded 1 m/s. The corrosion product mainly consisted of FeCO3 and FeS, and the average size of spherical corrosion product changed with flow rate. Besides, the percentage composition of FeS presented the same change trend as the average size of spherical corrosion product. In supercritical CO2 phase, wall shear stress was not big enough to cause mechanical damage on corrosion film but can affect the formation process and the characteristics of the corrosion film of X65 carbon steel.
6
Orazem, Mark E., Kevin J. Kennelley, and Lee Bone. "Current and Potential Distribution on a Coated Pipeline with Holidays: 2. a Comparison of the Effects of Discrete and Distributed Holidays." In CORROSION 1992. NACE International, 1992. https://doi.org/10.5006/c1992-92380.
Full textAbstract:
Abstract In contrast to standard practice, the current and potential distribution on a pipe must be considered if cathodic corrosion protection is to be provided with anodes placed in close proximity to the pipe. Correct design of a CP system will depend strongly on the types of holidays assumed to exist in pipe coating. Two models for the influence of holidays in coated pipes are compared that encompass the extremes of holiday distribution. The performance predicted by these models is compared to experiment. The design constraints for a pipe with a single coating holiday are shown to be much more severe than those for a pipe with a uniform coating efficiency reduced in proportion to the holiday area. The CP design must, therefore, account for discrete holidays if localized damage to the coating is anticipated. An approach to CP design is suggested in which a relationship is to be established between the percentage of pipe that is expected to be bare and the “effective” coating efficiency that can be used to design the cathodic protection system.
7
Burton, S. A., and M. Bonner. "Elastomeric Corrosion Protection Performance and Compatibility with Cathodic Protection Systems." In CORROSION 1985. NACE International, 1985. https://doi.org/10.5006/c1985-85286.
Full textAbstract:
Abstract The use of elastomers for the corrosion protection of steelwork is a subject of steadily growing interest, due to the realisation that severe environmental conditions on offshore structures require a coating capable of longevity without repetitive maintenance. From the first tentative steps 20 years ago in the Gulf of Mexico to the current application of high performance elastomers for complete riser protection systems in the North Sea, the evolution of the elastomeric coating has moved towards its recognition as a true engineering material. Existing corrosion protection systems often prove to be ineffective in one or a combination of specific requirements, for instance, poor initial bond strength;poor impact resistance;high water absorption;a high breakdown percentage for the standard 25 year lifetime requirement Individually or collectively, these effects may accelerate the onset of corrosion reactions and thus secondary protective systems become essential. However, the very nature of these weaknesses often create further complications when traditional cathodic protection systems are utilised. Such incompatibility with the cathodic protection system can initiate reactions which further destroy the protective coating causing an accelerating dependence on the secondary protection. It is the object of this paper to demonstrate that polychloroprene elastomer coatings provide excellent resistance to corrosion, erosion, impact damage and weathering, but primarily, it is intended to show that in the event of significant mechanical damage, polychloroprene provides a unique balance of properties to ensure the cathodic protective system remains effective over its life expectancy with minimal side reactions. All cathodic test work was carried out according to British Gas PS CW6 Test Method.
8
SHAHVERDI, SAJAD. "DAMAGE DETECTION OF RECTANGULAR SECTIONS BY 2D CURVELET, CONTOURLET AND WAVELET PACKET TRANSFORM." In Structural Health Monitoring 2023. Destech Publications, Inc., 2023. http://dx.doi.org/10.12783/shm2023/36830.
Full textAbstract:
In this research, the application of 2D curvelet, 2D wavelet, and Contourlet transform for damage detection of shell structure are presented. For this study, the equation of discrete curvelet transforms using unequally-spaced fast Fourier and wrapping transforms are employed. Four scenario models with one and more damages with different percentages and locations were considered for investigation of proposed methods. As real data has noise, and the existence of noise in the input data may affect the accuracy of damage detection methods. To consider the natural conditions, white noise has been applied to the data extracted from the FEM. First, the coefficients of transforms related to the noisy signal are calculated, then thresholding the previous coefficients calculated, and finally, the de-noise signal is reconstructed. Based on the presented results, the curvelet transform better identifies the location of damage than the wavelet transforms. Wavelet transform based on the direction of the damage element may be specified in some subbands. But in curvelet and Contourlet, it can better identify different damages in different directions due to the multi-directional transform. The curvelet transform has been modified based on polar space and poses challenges for non-polar (normal) discrete space. Therefore, using the Contourlet is divided into multiple directions because of each of the available general directions. According to the obtained results, the proposed methods are sensitive to the location and percentage of damage and can identify the location of damage with a low percentage of damage. Also, to confirm the results of the proposed methods, the results are evaluated using laboratory results. The results show that the proposed methods can identify the location of damages and with a percentage of damage of up to 3%.
9
Li, Jun, and Hong Hao. "Damage detection of gusset plate condtion in truss bridges based on wavelet packet energy percentage." In International Conference on Performance-based and Life-cycle Structural Engineering. School of Civil Engineering, The University of Queensland, 2015. http://dx.doi.org/10.14264/uql.2016.918.
Full text
10
Bordonaro, Giancarlo G., and Muhammad R. Hajj. "Parameter Sensitivities to Damage Progression in Structures." In ASME 2009 International Mechanical Engineering Congress and Exposition. ASMEDC, 2009. http://dx.doi.org/10.1115/imece2009-11354.
Full textAbstract:
Variations in the natural frequency and damping coefficients with cyclic fatigue testing in steel and composite beams carrying a lumped mass are assessed. The identification of these parameters is performed by exploiting the nonlinear behavior of the beam-mass system and matching an approximate solution of the representative model with quantities obtained from spectral analysis of measured vibrations. Percentage variations of the identified parameters during the tests and up to the point where cracks were observed are determined. The results show that the damping is more sensitive to damage progression than the natural frequency.
Reports on the topic "Damage Percentage"
1
Rahmani, Mehran, and Manan Naik. Structural Identification and Damage Detection in Bridges using Wave Method and Uniform Shear Beam Models: A Feasibility Study. Mineta Transportation Institute, 2021. http://dx.doi.org/10.31979/mti.2021.1934.
Full textAbstract:
This report presents a wave method to be used for the structural identification and damage detection of structural components in bridges, e.g., bridge piers. This method has proven to be promising when applied to real structures and large amplitude responses in buildings (e.g., mid-rise and high-rise buildings). This study is the first application of the method to damaged bridge structures. The bridge identification was performed using wave propagation in a simple uniform shear beam model. The method identifies a wave velocity for the structure by fitting an equivalent uniform shear beam model to the impulse response functions of the recorded earthquake response. The structural damage is detected by measuring changes in the identified velocities from one damaging event to another. The method uses the acceleration response recorded in the structure to detect damage. In this study, the acceleration response from a shake-table four-span bridge tested to failure was used. Pairs of sensors were identified to represent a specific wave passage in the bridge. Wave velocities were identified for several sensor pairs and various shaking intensities are reported; further, actual observed damage in the bridge was compared with the detected reductions in the identified velocities. The results show that the identified shear wave velocities presented a decreasing trend as the shaking intensity was increased, and the average percentage reduction in the velocities was consistent with the overall observed damage in the bridge. However, there was no clear correlation between a specific wave passage and the observed reduction in the velocities. This indicates that the uniform shear beam model was too simple to localize the damage in the bridge. Instead, it provides a proxy for the overall extent of change in the response due to damage.
2
Pelli, Martino, and Jeanne Tschopp. Storms, Early Education, and Human Capital. Asian Development Bank, 2024. http://dx.doi.org/10.22617/wps240462-2.
Full textAbstract:
Using wind exposure histories, the paper shows that exposure to an average storm can cause a 2.4 percentage point increase in educational delays, a 2 percentage point drop in post-secondary education attainment, and a 1.6 percentage point decline in regular salaried employment. The study also highlights the role of damaged school infrastructure and declining household income in driving these outcomes.
3
Cavallo, Eduardo A., Ana Cepeda, and Ugo Panizza. Environmental Damage News and Stock Returns: Evidence from Latin America. Inter-American Development Bank, 2024. http://dx.doi.org/10.18235/0012962.
Full textAbstract:
This paper studies the interplay between environmental performance and financial valuation of firms in Latin America and the Caribbean. We provide insights into how environmental considerations are integrated into financial decision-making and investor behavior by analyzing the stock market reaction to environmental news of firms with different levels of carbon emission intensity. We find that high emission intensity firms tend to underperform after the release of environmental damage news. Our baseline estimates indicate that, after the release of such news, firms at the 75th percentile of the distribution of emission intensity experience stock returns that are 17% lower than those of firms at the 25th percentile of the distribution of emission intensity. These results suggest that investors care about and price carbon risk, but only when this risk is salient.
4
Hansen, Peter J., and Zvi Roth. Use of Oocyte and Embryo Survival Factors to Enhance Fertility of Heat-stressed Dairy Cattle. United States Department of Agriculture, 2011. http://dx.doi.org/10.32747/2011.7697105.bard.
Full textAbstract:
The overall goal was to identify survival factors that can improve pregnancy success following insemination or embryo transfer in lactating dairy cows exposed to heat stress. First, we demonstrated that oocytes are actually damaged by elevated temperature in the summer. Then we tested two thermoprotective molecules for their effect on oocyte damage caused by heat shock. One molecule, ceramide was not thermoprptective. Another, insulin-like growth factor-1 (IGF) reduced the effects of heat shock on oocyte apoptosis and oocyte cleavage when added during maturation. We also used lactating cows exposed to heat stress to determine whether bovine somatotropin (bST), which increases IGF1 levels in vivo, would improve fertility in summer. Cows treated with bST received a single injection at 3 days before insemination. Controls received no additional treatment. Treatment with bST did not significantly increase the proportion of inseminated cows diagnosed pregnant although it was numerically greater for the bST group (24.2% vs 17.8%, 124–132 cows per group). There was a tendency (p =0.10) for a smaller percent of control cows to have high plasma progesterone concentrations (≥ 1 ng/ml) at Day 7 after insemination than for bST-treated cows (72.6 vs 81.1%). When only cows that were successfully synchronized were considered, the magnitude of the absolute difference in the percentage of inseminated cows that were diagnosed pregnant between bST and control cows was reduced (24.8 vs 22.4% pregnant for bST and control). Results failed to indicate a beneficial effect of bST treatment on fertility of lactating dairy cows. In another experiment, we found a tendency for addition of IGF1 to embryo culture medium to improve embryonic survival after embryo transfer when the experiment was done during heat stress but not when the experiment was done in the absence of heat stress. Another molecule tested, granulocyte-macrophage colony-stimulating factor (GM-CSF; also called colony-stimulating factor-2), improved embryonic survival in the absence of heat stress. We also examined whether heat shock affects the sperm cell. There was no effect of heat shock on sperm apoptosis (programmed cell death) or on sperm fertilizing ability. Therefore, effects of heat shock on sperm function after ejaculation if minimal. However, there were seasonal changes in sperm characteristics that indicates that some of the decrease in dairy cow fertility during the summer in Israel is due to using semen of inferior quality. Semen was collected from five representative bulls throughout the summer (August and September) and winter (December and January). There were seasonal differences in ion concentration in seminal plasma and in the mRNA for various ion channels known to be involved in acrosome reactions. Furthermore, the proportion of sperm cells with damaged acrosomes was higher in post-thaw semen collected in the summer than in its counterpart collected in winter (54.2 ± 3.5% vs. 51.4 ± 1.9%, respectively; P < 0.08Further examination is required to determine whether such alterations are involved in the low summer fertility of dairy cows.
5
Diehl, Rebecca, Jonathan Friedman, Rebecca Diehl, and Jonathan Friedman. Modelling effects of flow withdrawal scenarios on riverine and riparian features of the Yampa River in Dinosaur National Monument. National Park Service, 2024. http://dx.doi.org/10.36967/2305338.
Full textAbstract:
The National Park Service (NPS) is charged with maintaining natural riverine resources and processes in its parks along the Yampa River and downstream along the Green River. This mission requires information on how proposed water withdrawals would affect resources. We present a methodology that quantifies the impact on natural riverine and riparian features of Dinosaur National Monument based on alternative withdrawals that vary in volume and timing. This methodology uses a reverse quantification and develops tools to enable the NPS to ensure that if withdrawals must occur, the adverse impacts would be minimized by prescribing or constraining the timing, magnitude, and duration of withdrawal. The reverse quantification, well-suited for unregulated rivers such as the Yampa, strives to protect all flows minus extractions from daily flows based on three parameters: 1) a minimum flow, below which water diversion does not occur; 2) the percentage of the flow above the minimum that is diverted; 3) the maximum daily flow that is diverted. We apply 350 flow extraction scenarios, each defined by a unique set of parameters, to the 99 historic annual hydrographs of daily flows (water year (WY) 1922-2020), and to the more recent 20 years (WY 2001-2020). We also consider how hydrologic year type (wet to dry) influences the flow volume extracted and impact to the resource. Recognizing the seasonal differences in flow and ecological and geomorphic response, we divide each year into four distinct seasonal periods and use relations from the literature between flow, channel change, riparian vegetation and fish behavior, physiology, and habitat to define hydrograph and resource metrics used to evaluate impacts to the resource. While our analysis demonstrates that all withdrawals will damage the resource, extractions during the Early Runoff Period (March 15 ? April 30) are least detrimental and extractions during the Summer Baseflow Period (July 16 ? October 31) are most detrimental. We find that most aspects of the resource are more sensitive to increasing extractions during drier years than during wetter years. Recent decades have seen a shift towards more frequent drier years, resulting in less water in most periods. As a result, our analysis suggests that extractions in recent decades would have had a greater impact on the resource when compared to similar extractions during the full historical record. Finally, we demonstrate how the NPS may use these results to develop limits on extractions for resource protection.
6
Viksna, Ludmila, Oksana Kolesova, Aleksandrs Kolesovs, Ieva Vanaga, and Seda Arutjunana. Clinical characteristics of COVID-19 patients (Latvia, Spring 2020). Rīga Stradiņš University, 2020. http://dx.doi.org/10.25143/fk2/hnmlhh.
Full textAbstract:
Data include following variables: Demographics, epidemiological history, comorbidities, diagnosis, complications, and symptoms on admission to the hospital. Also, body’s temperature and SpO2. Blood cells: white cells count (WBC), neutrophils (Neu), lymphocytes (Ly), eosinophils (Eo) and monocytes (Mo), percentages of segmented and banded neutrophils, erythrocytes (RBC), platelet count (PLT), hemoglobin (Hb), and hematocrit (HCT); Inflammatory indicators: erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP); Tissue damage indicators: alanine aminotransferase (ALT), lactate dehydrogenase (LDH), and troponin T (TnT); Electrolytes: potassium and sodium concentration; Renal function indicators: creatinine and glomerular filtration rate (GFR); Coagulation tests: D-dimer, prothrombin time, and prothrombin index on admission to the hospital.
7
Mwamba, Isaiah C., Deepak Benny, Ajuna P. John, et al. Updating Cost Allocation and Revenue Attribution. Purdue University, 2024. http://dx.doi.org/10.5703/1288284317764.
Full textAbstract:
This report presents a synopsis of the results from the 2024 study commissioned by the Indiana Department of Transportation (INDOT) in fall 2023 at the request of the Indiana General Assembly. Expenditures: Lighter vehicle classes saw their share of cost responsibility decline between 2015 and 2024, while the heavier vehicle classes saw their responsibilities increase within this period. This change is explained by a diametric shift in expenditure type patterns between the two eras from construction-dominant to maintenance-dominant expenditures. In this context, it is worth noting that these expenditure types have different ratios of attributable costs to common costs. Revenues: Fifty-two percent (52%) of all user and non-user revenues are generated at the state level, 36% at the federal level, and 13% at the local level. Vehicle Classes 2 and 9 still contribute the highest shares of revenues—42% and 22%, respectively. Vehicle Class 3 contributes 21% of the revenues, while all other vehicles contribute less than 10% each. Vehicle Class 13 contributes the lowest percentage share at 0.1%. Across the two eras (2015 vs. 2024), Class 2 vehicles saw their revenue share decline from 47% to 42%, but Vehicle Class 9 increased from 20% in the earlier study (2015) to 22% in the current study (2024). Vehicle Class 3 held steady at 21% in both periods, while Classes 5 and 6 saw marginal increases. Equity Ratios: The equity ratio results follow a trend that is like those of past studies in Indiana and elsewhere. Generally, the lower vehicle classes are overpaying their share of cost responsibility and the higher vehicle classes are underpaying their share of cost responsibility. Notable shifts in equity ratios between the previous-era study and the current-era study were observed. Several lighter vehicle classes increased their equity ratios, while the heavier vehicles saw their equity ratios decline significantly between the two periods. EVs in Class 2 and Class 3 generally have lower equity ratios than their ICEV counterparts, a finding that is intuitive because EVs are associated with relatively higher damage but slightly lower, or similar, revenue contributions. For the forecast years (2030 and 2035), it was observed that EVs in Vehicle Classes 2 and 3 will be underpaying their share of the cost responsibility, while those in Classes 4 and 9 will be overpaying. The current EV fee that exists for these vehicles (if left unchanged) will not adequately cover their cost responsibility or recover the lost fuel tax revenues in 2030 and 2035.
8
Perera, Duminda, Ousmane Seidou, Jetal Agnihotri, et al. Flood Early Warning Systems: A Review Of Benefits, Challenges And Prospects. United Nations University Institute for Water, Environment and Health, 2019. http://dx.doi.org/10.53328/mjfq3791.
Full textAbstract:
Floods are major water-related disasters that affect millions of people resulting in thousands of mortalities and billiondollar losses globally every year. Flood Early Warning Systems (FEWS) - one of the floods risk management measures - are currently operational in many countries. The UN Office for Disaster Risk Reduction recognises their importance and strongly advocates for an increase in their availability under the targets of the Sendai Framework for Disaster Risk Reduction, and Sustainable Development Goals (SDGs). However, despite widespread recognition of the importance of FEWS for disaster risk reduction (DRR), there’s a lack of information on their availability and status around the world, their benefits and costs, challenges and trends associated with their development. This report contributes to bridging these gaps by analyzing the responses to a comprehensive online survey with over 80 questions on various components of FEWS (risk knowledge, monitoring and forecasting, warning dissemination and communication, and response capabilities), investments into FEWS, their operational effectiveness, benefits, and challenges. FEWS were classified as technologically “basic”, “intermediate” and “advanced” depending on the existence and sophistication of FEWS` components such as hydrological data = collection systems, data transfer systems, flood forecasting methods, and early warning communication methods. The survey questionnaire was distributed to flood forecasting and warning centers around the globe; the primary focus was developing and least-developed countries (LDCs). The questionnaire is available here: https://inweh.unu.edu/questionnaireevaluation-of-flood-early-warning-systems/ and can be useful in its own right for similar studies at national or regional scales, in its current form or with case-specific modifications. Survey responses were received from 47 developing (including LDCs) and six developed countries. Additional information for some countries was extracted from available literature. Analysis of these data suggests the existence of an equal number of “intermediate” and “advanced” FEWS in surveyed river basins. While developing countries overall appear to progress well in FEWS implementation, LDCs are still lagging behind since most of them have “basic” FEWS. The difference between types of operational systems in developing and developed countries appear to be insignificant; presence of basic, intermediate or advanced FEWS depends on available investments for system developments and continuous financing for their operations, and there is evidence of more financial support — on the order of USD 100 million — to FEWS in developing countries thanks to international aid. However, training the staff and maintaining the FEWS for long-term operations are challenging. About 75% of responses indicate that river basins have inadequate hydrological network coverage and back-up equipment. Almost half of the responders indicated that their models are not advanced and accurate enough to produce reliable forecasts. Lack of technical expertise and limited skilled manpower to perform forecasts was cited by 50% of respondents. The primary reason for establishing FEWS, based on the survey, is to avoid property damage; minimizing causalities and agricultural losses appear to be secondary reasons. The range of the community benefited by FEWS varies, but 55% of FEWS operate in the range between 100,000 to 1 million of population. The number of flood disasters and their causalities has declined since the year 2000, while 50% of currently operating FEWS were established over the same period. This decline may be attributed to the combined DRR efforts, of which FEWS are an integral part. In lower-middle-income and low-income countries, economic losses due to flood disasters may be smaller in absolute terms, but they represent a higher percentage of such countries’ GDP. In high-income countries, higher flood-related losses accounted for a small percentage of their GDP. To improve global knowledge on FEWS status and implementation in the context of Sendai Framework and SDGs, the report’s recommendations include: i) coordinate global investments in FEWS development and standardise investment reporting; ii) establish an international hub to monitor the status of FEWS in collaboration with the national responsible agencies. This will support the sharing of FEWS-related information for accelerated global progress in DRR; iii) develop a comprehensive, index-based ranking system for FEWS according to their effectiveness in flood disaster mitigation. This will provide clear standards and a roadmap for improving FEWS’ effectiveness, and iv) improve coordination between institutions responsible for flood forecasting and those responsible for communicating warnings and community preparedness and awareness.
9
Turner, John. Evaluation of Elongation Criteria and Friction Loss in Ground Anchors. Deep Foundations Institute, 2014. http://dx.doi.org/10.37308/cpf-2013-soil-1.
Full textAbstract:
This report describes a research project for evaluating the applicability of the widely accepted 80 percent criterion for elongation of ground anchors to anchors with unbonded lengths exceeding 100 feet. This issue is driven by several recent projects involving ground anchors for landslide stabilization in which a significant percentage of the anchors did not meet the criterion that requires measured elongation during proof load testing of at least 80 percent of the theoretical elastic elongation. The projects involved anchor unbonded lengths in the range of 85 to 220 feet, which is outside the range traditionally used in practice, although anchors of this length are being used more frequently for landslide stabilization. The principal objective of this research is to address whether the widely accepted criterion of 80 percent elongation is applicable for such applications, and whether other factors affect the ability of anchors to meet the criterion. Analytical methods for predicting transfer of load along the length of steel strand due to friction loss are used routinely in the prestressed concrete industry. These analytical expressions provide a rational framework for quantifying changes in load due to friction along the length of a ground anchor in terms of a ‘wobble coefficient’ (K) as defined in Aalami(2004). Values of the wobble coefficient for ground anchors can only be determined by back‐calculating from load tests, i.e., fit the value of K to the appropriate analytical expression based on the known test load and measured percent elongation. The analytical basis is first developed and shown to provide a tool for evaluating results of anchor load tests to determine the magnitude of expected elongation as a function of unbonded length. Next, a database of anchor load tests is used to back‐calculate values of K for anchors with unbonded lengths in the range typically used in geotechnical applications (<100feet). These values of K are then used to calculate expected friction loss for anchors with high unbonded lengths (100 to 250 feet) to evaluate whether the 80 percent criterion is reasonable. The primary findings of this research are: Field data data show a general trend of increasing rate of friction loss with increasing unbonded length, i.e., longer anchors are more likely to fail the 80‐percent minimum elongation criterion; Shallow anchor inclination appears to be a strong contributor to higher friction loss because it makes placement of the anchor into the hole difficult, requiring the anchor to be forced in, which may induce additional curvature and twisting; Factors that contribute to alignment deviations of the anchor drill hole, such as obstructions, discontinuities, or alternating hard and soft layers, also contribute to curvature and increase friction loss; Factors that result in forcing the anchor in to the hole, which for the cases considered involved a combination of long anchors, shallow inclination, and alignment deviations, increases the probability of anchor damage. For example, failure of the seal between the bond and unbonded segments of the anchor may allow grout to penetrate the sheathing, preventing elastic deformation of the strands.
10
Hammad, Ali, and Mohamed Moustafa. Seismic Behavior of Special Concentric Braced Frames under Short- and Long-Duration Ground Motions. Pacific Earthquake Engineering Research Center, University of California, Berkeley, CA, 2019. http://dx.doi.org/10.55461/zont9308.
Full textAbstract:
Over the past decade, several long-duration subduction earthquakes took place in different locations around the world, e.g., Chile in 2010, Japan in 2011, China in 2008, and Indonesia in 2004. Recent research has revealed that long-duration, large-magnitude earthquakes may occur along the Cascadia subduction zone of the Pacific Northwest Coast of the U.S. The duration of an earthquake often affects the response of structures. Current seismic design specifications mostly use response spectra to identify the hazard and do not consider duration effects. Thus, a comprehensive understanding of the effect of the duration of the ground motion on structural performance and its design implications is an important issue. The goal of this study was to investigate how the duration of an earthquake affects the structural response of special concentric braced frames (SCBFs). A comprehensive experimental program and detailed analytical investigations were conducted to understand and quantify the effect of duration on collapse capacity of SCBFs, with the goal of improving seismic design provisions by incorporating these effects. The experimental program included large-scale shake table tests, and the analytical program consisted of pre-test and post-test phases. The pre-test analysis phase performed a sensitivity analysis that used OpenSees models preliminarily calibrated against previous experimental results for different configuration of SCBFs. A tornado-diagram framework was used to rank the influence of the different modeling parameters, e.g., low-cycle fatigue, on the seismic response of SCBFs under short- and long-duration ground motions. Based on the results obtained from the experimental program, these models were revisited for further calibration and validation in the post-test analysis. The experimental program included three large-scale shake-table tests of identical single-story single-bay SCBF with a chevron-brace configuration tested under different ground motions. Two specimens were tested under a set of spectrally-matched short and long-duration ground motions. The third specimen was tested under another long-duration ground motion. All tests started with a 100% scale of the selected ground motions; testing continued with an ever-increasing ground-motion scale until failure occurred, e.g., until both braces ruptured. The shake table tests showed that the duration of the earthquake may lead to premature seismic failure or lower capacities, supporting the initiative to consider duration effects as part of the seismic design provisions. Identical frames failed at different displacements demands because of the damage accumulation associated with the earthquake duration, with about 40% reduction in the displacement capacity of the two specimens tested under long-duration earthquakes versus the short-duration one. Post-test analysis focused first on calibrating an OpenSees model to capture the experimental behavior of the test specimens. The calibration started by matching the initial stiffness and overall global response. Next, the low-cycle fatigue parameters were fine-tuned to properly capture the experimental local behavior, i.e., brace buckling and rupture. The post-test analysis showed that the input for the low-cycle fatigue models currently available in the literature does not reflect the observed experimental results. New values for the fatigue parameters are suggested herein based on the results of the three shake-table tests. The calibrated model was then used to conduct incremental dynamic analysis (IDA) using 44 pairs of spectrally-matched short- and long-duration ground motions. To compare the effect of the duration of ground motion, this analysis aimed at incorporating ground-motion variability for more generalized observations and developing collapse fragility curves using different intensity measures (IMs). The difference in the median fragility was found to be 45% in the drift capacity at failure and about 10% in the spectral acceleration (Sa). Using regression analysis, the obtained drift capacity from analysis was found to be reduced by about 8% on average for every additional 10 sec in the duration of the ground motion. The last stage of this study extended the calibrated model to SCBF archetype buildings to study the effect of the duration of ground motion on full-sized structures. Two buildings were studied: a three-story and nine-story build that resembled the original SAC buildings but were modified with SCBFs as lateral support system instead of moment resisting frames. Two planer frames were adopted from the two buildings and used for the analysis. The same 44 spectrally-matched pairs previously used in post-test analysis were used to conduct nonlinear time history analysis and study the effect of duration. All the ground motions were scaled to two hazard levels for the deterministic time history analysis: 10% exceedance in 50 years and 2% exceedance in 50 years. All analysis results were interpreted in a comparative way to isolate the effect of duration, which was the main variable in the ground-motion pairs. In general, the results showed that the analyzed SCBFs experienced higher drift values under the long-duration suite of ground motions, and, in turn, a larger percentage of fractured braces under long-duration cases. The archetype SCBFs analysis provided similar conclusions on duration effects as the experimental and numerical results on the single-story single-bay frame.