45 research outputs found
Geotechnical remediation of transportation infrastructures: nondestructive evaluation of bridge substructures and stabilization of soft foundation soils
According to the National Research Council (2006), the field of infrastructure development and rehabilitation is one of seven critical categories that require attention of geotechnical researchers and practitioners. Therefore, in this dissertation, two topics related to infrastructure development were selected and studies. These topics were performance of granular shoulders and nondestructive evaluation of low volume road bridge substructures. The first topic investigated common problems associated with granular shoulders, evaluation of several test sections stabilized with selected chemical and mechanical stabilization techniques, laboratory box model, where mechanically stabilized shoulders were tested under cyclic loading, and simple design charts that can help design stable shoulder sections. The second topic evaluates the effectiveness of using nondestructive ultrasonic stress wave tests to determine the internal timber piles conditions and correlate it to capacity of in-service piles. Also, the results of a destructive static load are presented. During this test, the timber piles at one abutment, instrumented with strain gages and load cells, were consecutively damaged to simulate different scenarios of pile deterioration. The influence of this deterioration on the bridge substructure behavior was evaluated
Aortic valve repair in patients with ventricular septal defect or subaortic membrane
Background: The delay in the surgical intervention of subaortic ventricular septal defect (VSD) and subaortic membrane leads to significant damage in the aortic valve, and multiple surgical interventions may be needed. We aimed to describe the pathology of the aortic valve in patients with subaortic membrane or VSD and different surgical strategies to manage the aortic regurgitation in those patients.
Methods: The study included patients who had surgery for subaortic membrane or VSD from 2017 to 2021. We reviewed strategies and surgical techniques to deal with aortic regurgitation in patients with subaortic membrane or VSD and the short and midterm outcomes.
Results: Twelve cases were included in the study; 5 cases had subaortic membrane, and 7 cases had subaortic VSD. The age ranged from 1.5 to 10 years old. Postoperative follow-up ranged from 1 to 3.5 years. We performed sub-commissural stitches and peeling of the leaflets to correct residual regurgitation. Four patients with subaortic membrane achieved satisfactory outcomes, and one patient had severe aortic regurgitation. Two patients with VSD had progression of the aortic regurgitation. Patients with failed repair had severe prolapse and thickening of the valve.
Conclusion: Severe prolapse and dense thickening of the valve were difficult pathologies to repair. The sub-commissural stitches could be mandatory to achieve good midterm results. Complete freeing and peeling of the leaflets till restoring the natural appearance is crucial
Investigation of Steel-Stringer Bridges: Superstructures and Substructures, Volume II
Problems with unknown bridge foundations in Iowa are often associated with timber substructures. Timber piles are subject to biological and physical deterioration, which makes quantifying in-service pile capacity difficult. Currently there are no reliable means to estimate the residual carrying capacity of an in-service deteriorated pile; and thus, the overall safety of the bridge cannot be determined. The lack of reliable evaluation methods can lead to conservative and costly maintenance practices. This research study was undertaken to investigate procedures for assessing bridge substructures, and evaluating procedures for rehabilitating/strengthening/replacing inadequate substructure components. The report includes an extensive literature review, a field reconnaissance study of 49 bridges, a survey of substructure problems from the perspective of County Engineers, a laboratory study aiming to correlate nondestructive tests to residual pile strength and stiffness values, nondestructive and destructive load tests for 6 bridges with poor substructures, and finally a laboratory study evaluating selected repair methods
Effective Shoulder Design and Maintenance
Shoulders are an important element of the highway system, providing space for emergency stops, a recovery zone for errant vehicles, structural support for the pavement, drainage, improved sight distance, passage for bicyclists, and increased roadway width to accommodate agricultural vehicles.
Granular shoulders are a commonly used shoulder option. Although the construction of granular shoulders is initially less expensive than that of paved shoulders (by up to 70%), granular shoulders often add expense later because they require more frequent maintenance and have performance problems. Common granular shoulder problems include edge drop-off, shoulder rutting, erosion by water or wind, irregular slope, and settlement of the subgrade soil.
Current maintenance procedures for granular shoulders in Iowa typically involve shoulder regrading, placing additional material, and recompaction. These maintenance and repair problems are costly and require investigation to illuminate the factors that contribute to these problem
Leverage of Matricaria chamomilla L. Oil Supplementation over Ochratoxin A in Growing Quails
Ochratoxin A (OTA) is one of the mycotoxins in the agriculture and livestock sectors. The poultry sector su3ered from significant economic losses due to the adverse impacts of OTA on the growth rate, feed conversion ratio, and livability. Thus, the present investigation aimed to determine the impact of chamomile essential oil supplementation against OTA toxicity in growing quails. 360 one-week-old growing quails were distributed into six groups (n = 60) with four replicates of 15 birds. The groups were G1 (control negative), G2 (OTA 1 mg/kg diet, control positive), G3 (chamomile oil 0.5 g/kg diet), G4 (chamomile oil 1 g/kg diet), G5 (OTA 1 mg/kg diet + chamomile oil 0.5 g/kg diet), and G6 (OTA 1 mg/kg diet + chamomile oil 1 g/kg diet). Adding OTA significantly (P < 0.05) reduced live body weight and weight gain at 5 weeks. Feed intake at 5 weeks was non significantly reduced in G3 and G4 compared to G1. G4 showed a significant (P < 0.05) increase in weight gain and the lowest feed conversion ratio. The G2 showed the lowest superoxide dismutase (SOD), total antioxidant capacity (TAC), glutathione transferase (GST) activity, and the highest levels of malondialdehyde (MDA). Moreover, they showed a significant improvement in liver enzymes and kidney function tests and a significant (P < 0.05) reduction in the levels of total cholesterol and triglycerides. Chamomile supplementation alone or with OTA significantly (P < 0.05) increased immunoglobulin M, G, A, and complement 3 than OTA alone. Chamomile oil with an OTA diet or alone reduced the negative effects of OTA and improved the performance, antioxidant status, lipid profile, and immunological state of growing Japanese quails
The role of chamomile oil against ochratoxin A in quail breeders: productive and reproductive performances, egg quality and blood metabolites
This study aimed to evaluate the beneficial role of chamomile essential oil in improving productive and reproductive performances, egg quality, and blood metabolites and reducing the toxic effect of Ochratoxin A (OTA) in quail breeder's diets. A total of 144 mature quails, 8 wk old, were divided into 6 groups. The treatments were: G1 (the control), G2 (supplemented with OTA 1 mg/kg diet), G3 (supplemented with chamomile oil 0.5 g/kg diet), G4 (supplemented with chamomile oil 1 G/kg diet), G5 (supplemented with OTA 1 mg/kg diet + chamomile oil 0.5 g/kg diet), and G6 (supplemented with OTA 1 mg/kg diet + chamomile oil 1 g/kg diet). The OTA administration alone significantly decreased egg production and mass in quail breeders (P < 0.0001). Moreover, poor feed conversion ratio (FCR), fertility percentage (P < 0.0001), and hatchability percentage (P < 0.0009) were recorded. A significant decline (P < 0.05) in the levels of serum protein (total protein and globulin) was also recorded in OTA-contaminated groups, along with elevated serum levels of liver enzymes such as alanine transaminase (ALT) and Aspartate transaminase (AST) and kidney function test as urea and creatinine levels (P < 0.05). Ochratoxin A-contaminated feed resulted in a significant elevation (P < 0.05) in total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL), and very low-density lipoprotein (VLDL), along with a significant reduction (P < 0.05) in antioxidant status and immunological response. The supplementation of chamomile essential oil, either 0.5 g/kg or 1g/kg, to the basal diet or OTA-supplemented feed, revealed a significant increase in hatchability %, fertility, egg mass, and egg production and better FCR, egg quality, and immunological status when compared to OTA only. Moreover, chamomile essential oil supplementation improves liver and kidney function markers, decreases LDL, VLDL), TG, and TC. Along with a significant increase (P < 0.05) in terms of antioxidant status as glutathione peroxidase enzyme (GPX), total antioxidant capacity (TAC), and superoxide dismutase (SOD) and significantly (P < 0.05) improves immunological response as IgM, IgG, lysozyme and complement 3. In summary, chamomile oil supplementation, either separate or combined with OTA, reduced the adverse effects of OTA and led to improved productive and reproductive performance, egg quality, and blood metabolites in Japanese quail breeders
Operating a recurrent synovial sarcoma of the sternoclavicular joint: a case presentation
Background: Synovial sarcoma is one of the rarest soft tissue tumor with a high grade of malignancy. Primary synovial sarcoma of the chest wall is rare.
Presentation of case: A 65-year-old woman presented with history of left upper chest wall mass previously operated 9 months ago. The pathological report was a synovial sarcoma. Computed chest tomography was done and revealed a RT anterior infraclavicular mass with cystic a solid lesions measuring 8.5 *3.5*4 cm.
Conclusion: The synovial sarcoma is aggressive malignancy and we think from the story of this case that early radical surgery plus systemic chemotherapy provides better outcome
Management of water and backfill characteristics for improved bridge approach performance
Bridge approach settlement is a problem that draws upon resources for maintenance and repair, causes damage to vehicles, and creates a negative perception of the transportation agency. To alleviate bridge approach settlement, erosion and soil collapse must be reduced. This can be accomplished by improving water management around bridges and backfill characteristics. The purpose of this study was to examine the effects of improved water management and backfill properties on settlement of bridge approaches and to recommend new alternatives for design, construction, and maintenance of new and existing bridge approaches. Furthermore, recommend a threshold limit for approach slab settlement as a criterion to initiate maintenance. The objectives of this research are a literature review of relevant research of practices of other states, field inspection of existing and under construction bridges, monitoring of maintenance practices, laboratory experiments to analyze the properties of various backfill materials and geosynthetic drainage materials, and developing a new rating system as a criterion to initiate maintenance. To analyze the characteristics of backfill materials, the collapse index test was performed to measure the change in volume of the different backfill materials upon saturation at different moisture contents. Vibrating table tests (ASTM D4253-00) were performed, and a one-fourth scale model of a bridge approach was constructed in an effort to evaluate geosynthetic drainage materials as well as a variety of drainage details. This study reveals that poor water management is a major cause of bridge approach problems. Further, granular backfill materials placed within the bulking moisture content range are susceptible to collapse upon saturation. Proper compaction of granular backfill materials and placing porous backfill around subdrains is not being followed during construction. Grouting behind abutments and resurfacing of approach slabs do not necessarily prevent further settlements. The URETEK Inc. maintenance method appears to be a successful alternative to conventional maintenance practices; however, the long term performance is yet to be verified. The constructed model illustrated that using porous backfill, geocomposite vertical drain, and tire chips improved the bridge approach performance. The bridge Approach Index parameter and the IRI data were used as a new rating system.</p
Management of water and backfill characteristics for improved bridge approach performance
Bridge approach settlement is a problem that draws upon resources for maintenance and repair, causes damage to vehicles, and creates a negative perception of the transportation agency. To alleviate bridge approach settlement, erosion and soil collapse must be reduced. This can be accomplished by improving water management around bridges and backfill characteristics. The purpose of this study was to examine the effects of improved water management and backfill properties on settlement of bridge approaches and to recommend new alternatives for design, construction, and maintenance of new and existing bridge approaches. Furthermore, recommend a threshold limit for approach slab settlement as a criterion to initiate maintenance. The objectives of this research are a literature review of relevant research of practices of other states, field inspection of existing and under construction bridges, monitoring of maintenance practices, laboratory experiments to analyze the properties of various backfill materials and geosynthetic drainage materials, and developing a new rating system as a criterion to initiate maintenance. To analyze the characteristics of backfill materials, the collapse index test was performed to measure the change in volume of the different backfill materials upon saturation at different moisture contents. Vibrating table tests (ASTM D4253-00) were performed, and a one-fourth scale model of a bridge approach was constructed in an effort to evaluate geosynthetic drainage materials as well as a variety of drainage details. This study reveals that poor water management is a major cause of bridge approach problems. Further, granular backfill materials placed within the bulking moisture content range are susceptible to collapse upon saturation. Proper compaction of granular backfill materials and placing porous backfill around subdrains is not being followed during construction. Grouting behind abutments and resurfacing of approach slabs do not necessarily prevent further settlements. The URETEK Inc. maintenance method appears to be a successful alternative to conventional maintenance practices; however, the long term performance is yet to be verified. The constructed model illustrated that using porous backfill, geocomposite vertical drain, and tire chips improved the bridge approach performance. The bridge Approach Index parameter and the IRI data were used as a new rating system