Use of Longitudinal Subdrains in the 3R Program, HR-509, Progress Report #2, 1981

The main consideration for base construction under the pavement, in the design of Iowa's interstate, was structural capacity. The material was dense graded with the aim of supporting the pavement and distributing the load as it is transferred to the underlying grade. The drainage characteristics of the base was apparently not given adequate consideration. On jointed portland cement concrete pavement, the water that is trapped immediately beneath the pavement causes severe problems. The traffic causes rapid movement of the water resulting in the hydraulic pressures or "pumping" (movement and redeposit of base fine material), further resulting in faulting between individual slabs. The objective of this evaluation is to determine if longitudinal subdrains are effective in preventing or reducing pumping, faulting and related deterioration. Results suggest that, based upon the flow from the outlets observed during periodic checks and evidence of water flow at the outlets, it appears that to date the subdrains are effective in draining the subbase and subgrade. Because of the limited data available at this time, however, the pavement condition and faulting results are inconclusive.

Asphalt Cement Concrete Longitudinal Joint Adhesive Crafco PN 34524 (Iowa DOT New Product C-98-7), HR-2084, 2000

The joint between two lanes of asphalt pavement is often the first area of a roadway which shows signs of deterioration and requires maintenance. As the final lift of hot asphalt is being placed in a construction project, it is being forced p against the adjoining lane of cold asphalt, forming the longitudinal joint. The mating of the two lanes, to form a high quality seal, is often not fully successful and later results in premature stripping or raveling as water enters the unsealed joint. The application of a hot poured rubberized asphaltic joint sealant along the joint face in the final stage of construction should help to form a watertight joint seal. A new product, especially formulated for the longitudinal joint in asphalt pavements was proposed to improve joint sealing. The following describes the experimental application of the new product, Crafco, PN 34524.

Visualization of aqueous shunt position and patency using anterior segment optical coherence tomography.

PURPOSE: To describe the use of anterior segment optical coherence tomography (AS-OCT) to clarify the position and patency of aqueous shunt devices in the anterior chamber of eyes where corneal edema or tube position does not permit a satisfactory view. DESIGN: Noncomparative observational case series. METHODS: Four cases are reported in which aqueous shunt malposition or obstruction was suspected but the shunt could not be seen on clinical examination. The patients underwent AS-OCT to identify the position and patency of the shunt tip. RESULTS: In each case, AS-OCT provided data regarding tube position and/or patency that could not be obtained by slit-lamp examination or by gonioscopy that influenced management. CONCLUSIONS: AS-OCT can be used to visualize anterior chamber tubes in the presence of corneal edema that precludes an adequate view or in cases where the tube is retracted into the cornea. In such cases, AS-OCT is useful in identifying shunt patency and position, which helps guide clinical decision making.

Longitudinal Grinding and Transverse Grooving to Improve Frictional and Profile Properties, HR-1035, 1983

There are many miles of portland cement concrete pavement in Iowa that due to normal wear, and in some cases accelerated wear from studded tires, the surface has become polished resulting in less than desirable friction values. Retexturing the surface may be an economical way to re-establish desirable friction values. Retexturing by grinding with diamond blades and transverse grooving with diamond blades are two methods of rehabilitating p.c.c. surfaces. MU Inc. of Lebanan, Tennessee proposed to provide without charge to the Iowa Department of Transportation, one 1500 ft x 12 ft section each of three methods of texturing. They are longitudinal grinding, transverse grooving and longitudinal grinding followed by transverse grooving. A section of 1500 feet is needed to properly evaluate a texturing method. It was decided by Iowa DOT personnel that due to possible differential friction it would be undesirable to texture only one lane. The decision was made to do test sections of 1500 ft x 24 ft with the cost of the additional texturing paid by the Iowa DOT. Iowa also has areas where the p.c.c. pavement has faulted at the joints and cracks which results in poor riding quality. Methods of correcting the faulting are to underseal the pavement where needed and/or grinding the surface to eliminate the faulted areas. It was decided to include in this research project a section for profiling by grinding.

Improving Subgrade Support Values with Longitudinal Drains, MLR-84-3, 1984

This report is a brief summary of research on the effect of longitudinal drains on subgrade support. The Iowa DOT began installing longitudinal subdrains at a depth of 24" in 1978. The trend in Iowa has been to deeper longitudinal drains with the present standard being 48" deep. A very limited amount of data would indicate that the deeper longitudinal drains are providing a greater benefit to the subgrade support value. The 24# deep drains of the Poweshiek Interstate 80 project yielded a spring subgrade support value of 165. The 30" deep drains on Pottawattamie Interstate 80 yielded a K value of 170 while the 48"deep drains on Cass County Interstate 80 yielded a K value of 210. This limited amount of data would indicate that the deeper drains provide greater benefit to improvement of the subgrade support values.

Use of Longitudinal Subdrains in the 3R Program, Progress Report 1, HR-509, 1980

The main consideration for base construction under the pavement, in the design of Iowa's interstate, was structural capacity. The material was dense graded with the aim of supporting the pavement and distributing the load as it is transferred to the underlying grade. The drainage characteristics of the base was apparently not given adequate consideration. On jointed portland cement concrete pavement, the water that is trapped immediately beneath the pavement causes severe problems. The traffic causes rapid movement of the water resulting in the hydraulic pressures or "pumping" (movement and redeposit of base fine material), further resulting in faulting between individual slabs. The objective of this evaluation is to determine if longitudinal subdrains are effective in preventing or reducing pumping, faulting and related deterioration. Results suggest that, based upon the flow from the outlets observed during periodic checks and evidence of water flow at the outlets, it appears that to date the subdrains are effective in draining the subbase and subgrade. Because of the limited data available at this time, however, the pavement condition and faulting results are inconclusive.

Use of Longitudinal Subdrains in the 3R Program, Final Report, HR-509, 1981

Construction of the interstate highway system began in 1956. This U.S. network of highway consists of more than 41,000 miles with 790 miles in Iowa. There have been many benefits of the controlled access roadway, but probably the most significant is the improved safety for the motorist. In Iowa, we have always endeavored to utilize quality locally available materials in our construction using the most economical or cost effective methods. Obviously when the effort is to build a cost effective system, there will be some portions of the network that will not perform as well as expected. In the design of our interstate, the main consideration for base construction under the pavement was structural capacity. The material was dense graded with the aim of supporting the pavement and distributing the load as it is transferred to the underlying grade. The drainage characteristic of the base was apparently not given adequate consideration. On jointed portland cement concrete (pcc) pavement, the water that is trapped immediately beneath the pavement causes severe problems. The traffic causes rapid movement of the water resulting in the hydraulic pressures or "pumping" (movement and redeposit of base fine material) resulting in faulting between individual slabs. Recognizing the need for maintaining this large national highway network, the Federal Highway Administration has initiated a funding program for resurfacing, restoration and rehabilitation (3R). Many miles of the system are more than 20 years old and in need of major maintenance. This new 3R Program necessitated a complete inventory of the Iowa interstate system to establish priorities and to identify those sections in need of immediate remedial treatments.

Effect of supplementation with vitamin D3 and calcium on quantitative ultrasound of bone in elderly institutionalized women: a longitudinal study.

Supplementation of elderly institutionalized women with vitamin D and calcium decreased hip fractures and increased hip bone mineral density. Quantitative ultrasound (QUS) measurements can be performed in nursing homes, and easily repeated for follow-up. However, the effect of the correction of vitamin D deficiency on QUS parameters is not known. Therefore, 248 institutionalized women aged 62-98 years were included in a 2-year open controlled study. They were randomized into a treated group (n = 124), receiving 440 IU of vitamin D3 combined with 500 mg calcium (1250 mg calcium carbonate, Novartis) twice daily, and a control group (n = 124). One hundred and three women (42%), aged 84.5 +/- 7.5 years, completed the study: 50 in the treated group, 53 in the controls. QUS of the calcaneus, which measures BUA (broadband ultrasound attenuation) and SOS (speed of sound), and biochemical analysis were performed before and after 1 and 2 years of treatment. Only the results of the women with a complete follow-up were taken into account. Both groups had low initial mean serum 25-hydroxyvitamin D levels (11.9 +/- 1.2 and 11.7 +/- 1.2 micrograms/l; normal range 6.4-40.2 micrograms/l) and normal mean serum parathyroid hormone (PTH) levels (43.1 +/- 3.2 and 44.6 +/- 3.5 ng/l; normal range 10-70 ng/l, normal mean 31.8 +/- 2.3 ng/l). The treatment led to a correction of the metabolic disturbances, with an increase in 25-hydroxyvitamin D by 123% (p < 0.01) and a decrease in PTH by 18% (p < 0.05) and of alkaline phosphatase by 15% (p < 0.01). In the controls there was a worsening of the hypovitaminosis D, with a decrease of 25-hydroxyvitamin D by 51% (p < 0.01) and an increase in PTH by 51% (p < 0.01), while the serum calcium level decreased by only 2% (p < 0.01). After 2 years of treatment BUA increased significantly by 1.6% in the treated group (p < 0.05), and decreased by 2.3% in the controls (p < 0.01). Therefore, the difference in BUA between the treated subjects and the controls (3.9%) was significant after 2 years (p < 0.01). However, SOS decreased by the same amount in both groups (approximately 0.5%). In conclusion, BUA, but not SOS, reflected the positive effect on bone of supplementation with calcium and vitamin D3 in a population of elderly institutionalized women.

Advanced optical microscopies for materials: new trends

This article summarizes the new trends of Optical Microscopy applied to Materials, with examples of applications that illustrate the capabilities of thetechnique.

Magnetism of isolated Mn12 single-molecule magnets detected by magnetic circular dichroism: Observation of spin tunneling with a magneto-optical technique

We report magnetic and magneto-optical measurements of two Mn12 single-molecule magnet derivatives isolated in organic glasses. Field-dependent magnetic circular dichroism (MCD) intensity curves (hysteresis cycles) are found to be essentially identical to superconducting quantum interference device magnetization results and provide experimental evidence for the potential of the optical technique for magnetic characterization. Optical observation of magnetic tunneling has been achieved by studying the decay of the MCD signal at weak applied magnetic field

Surface reconstruction from microscopic images in optical lithography.

This paper presents a method to reconstruct 3D surfaces of silicon wafers from 2D images of printed circuits taken with a scanning electron microscope. Our reconstruction method combines the physical model of the optical acquisition system with prior knowledge about the shapes of the patterns in the circuit; the result is a shape-from-shading technique with a shape prior. The reconstruction of the surface is formulated as an optimization problem with an objective functional that combines a data-fidelity term on the microscopic image with two prior terms on the surface. The data term models the acquisition system through the irradiance equation characteristic of the microscope; the first prior is a smoothness penalty on the reconstructed surface, and the second prior constrains the shape of the surface to agree with the expected shape of the pattern in the circuit. In order to account for the variability of the manufacturing process, this second prior includes a deformation field that allows a nonlinear elastic deformation between the expected pattern and the reconstructed surface. As a result, the minimization problem has two unknowns, and the reconstruction method provides two outputs: 1) a reconstructed surface and 2) a deformation field. The reconstructed surface is derived from the shading observed in the image and the prior knowledge about the pattern in the circuit, while the deformation field produces a mapping between the expected shape and the reconstructed surface that provides a measure of deviation between the circuit design models and the real manufacturing process.

Line search multilevel optimization as computational methods for dense optical flow

We evaluate the performance of different optimization techniques developed in the context of optical flow computation with different variational models. In particular, based on truncated Newton methods (TN) that have been an effective approach for large-scale unconstrained optimization, we de- velop the use of efficient multilevel schemes for computing the optical flow. More precisely, we evaluate the performance of a standard unidirectional mul- tilevel algorithm - called multiresolution optimization (MR/OPT), to a bidrec- tional multilevel algorithm - called full multigrid optimization (FMG/OPT). The FMG/OPT algorithm treats the coarse grid correction as an optimiza- tion search direction and eventually scales it using a line search. Experimental results on different image sequences using four models of optical flow com- putation show that the FMG/OPT algorithm outperforms both the TN and MR/OPT algorithms in terms of the computational work and the quality of the optical flow estimation.

Contribution of genome-wide significant single-nucleotide polymorphisms and antiretroviral therapy to dyslipidemia in HIV-infected individuals: a longitudinal study.

BACKGROUND: HIV-infected individuals have an increased risk of myocardial infarction. Antiretroviral therapy (ART) is regarded as a major determinant of dyslipidemia in HIV-infected individuals. Previous genetic studies have been limited by the validity of the single-nucleotide polymorphisms (SNPs) interrogated and by cross-sectional design. Recent genome-wide association studies have reliably associated common SNPs to dyslipidemia in the general population. METHODS AND RESULTS: We validated the contribution of 42 SNPs (33 identified in genome-wide association studies and 9 previously reported SNPs not included in genome-wide association study chips) and of longitudinally measured key nongenetic variables (ART, underlying conditions, sex, age, ethnicity, and HIV disease parameters) to dyslipidemia in 745 HIV-infected study participants (n=34 565 lipid measurements; median follow-up, 7.6 years). The relative impact of SNPs and ART to lipid variation in the study population and their cumulative influence on sustained dyslipidemia at the level of the individual were calculated. SNPs were associated with lipid changes consistent with genome-wide association study estimates. SNPs explained up to 7.6% (non-high-density lipoprotein cholesterol), 6.2% (high-density lipoprotein cholesterol), and 6.8% (triglycerides) of lipid variation; ART explained 3.9% (non-high-density lipoprotein cholesterol), 1.5% (high-density lipoprotein cholesterol), and 6.2% (triglycerides). An individual with the most dyslipidemic antiretroviral and genetic background had an approximately 3- to 5-fold increased risk of sustained dyslipidemia compared with an individual with the least dyslipidemic therapy and genetic background. CONCLUSIONS: In the HIV-infected population treated with ART, the weight of the contribution of common SNPs and ART to dyslipidemia was similar. When selecting an ART regimen, genetic information should be considered in addition to the dyslipidemic effects of ART agents.