Subgrade Design Inputs

The Resilient Modulus (MR) of soils is crucial in pavement design. We will discuss testing and interpretation of soil MR and present a simple procedure to estimate it

Importance of Resilient Modulus (MR) and it\u27s Interpretation Subgrade Design Inputs

The Resilient Modulus (MR) of soils is crucial in pavement design. We will discuss testing and interpretation of soil MR and present a simple procedure to estimate it

2020 ATL Pavement Design: A Case Study

Four projects on I-65 were selected, designed, and constructed as 2020 ATL (added travel lanes) projects. During the pavement design stages, six alternatives with MEPDG (Mechanistic Pavement Design Guide) analysis, cost (per lane miles), and LCCA (life cycle cost analysis) were considered. Ultimately all projects were selected to be total reconstruction with an alternate bid (HMA vs. concrete) in anticipation of a lower bidding cost. In the end, INDOT saved 14% on these projects ($200M total cost). In this session we will describe various alternate pavement design analyses with cost analysis

Rehabilitation of I-70 Composite Pavement Using Peel and Stick Strip Membrane & Geosynthetic Paving Fabric Interlayer

I-70 composite (asphalt over concrete) pavement is being rehabilitated using peel and stick membrane and geosynthetic paving fabric. The innovative rehabilitation technique is the first time peel and stick membrane is being used with geosynthetic paving fabric on the existing concrete pavement of the interstate. This combination retards reflective cracking and acts as a moisture barrier, which extends the service life of the treatment

US 41 Crack & Seat Case Study A Practical Design

Crack and seat is one of the most cost-effective pavement rehabilitation techniques for existing old concrete with major distresses such as D cracking and joint failures. Using the MEPDG, INDOT saved $20 million from its proposed$33 million budget for this project

Triple mesh technique in repair of recurrent lumbar incisional hernia

Lumbar hernias occur infrequently and can be congenital, primary (inferior or Petit type, and superior or Grynfeltt type), post-traumatic, or incisional. They are bounded by the 12th rib, the iliac crest, the erector spinae, and the external oblique muscle. Most postoperative incisional hernias occur in nephrectomy or aortic aneurysm repair incisions for which various surgical method in context of meshplasty are available. In this case 60 yr. male hypertensive patient presented to the outpatient clinic of institute with recurrent left side lumbar incisional hernia, patient was previously operated for left side nephrolithiasis 15 years back and onlay meshplasty 2 years back for incisional hernia. The patient was operated under high risk for recurrent incisional hernia repair by triple layered meshplasties in the same sitting. Lumbar incisional hernias are often diffuse with fascial defects that are usually hard to appreciate. Computed tomography scan is the diagnostic modality of choice with adjuvant clinical findings, which allows differentiating them from abdominal wall musculature denervation atrophy complicating flank incisions. Repairing these hernias is difficult due to the surrounding structures for which our surgical approach included a triple mesh repair consisting of underlay, inlay and onlay meshplasty thereby anticipating further such incidences of incisional hernia

Probing ultrafast dynamics in a solid-density plasma created by an intense femtosecond laser

We report a study on the dynamics of a near-solid density plasma using an ultraviolet (266 nm) femtosecond probe laser pulse, which can penetrate to densities of ∼ 1022 cm-3, nearly an order of magnitude higher than the critical density of the 800 nm, femtosecond pump laser. Time-resolved probe-reflectivity from the plasma shows a rapid decay (picosecond- timescale) while the time-resolved reflected probe spectra show red shifts at early temporal delays and blue shifts at longer delays. This spectral behaviour of the reflected probe can be explained by a laser-driven shock moving inward and a subsequent hydrodynamic free expansion in the outward direction

Temporal Deconvolution study of Long and Short Gamma-Ray Burst Light curves

The light curves of Gamma-Ray Bursts (GRBs) are believed to result from internal shocks reflecting the activity of the GRB central engine. Their temporal deconvolution can reveal potential differences in the properties of the central engines in the two populations of GRBs which are believed to originate from the deaths of massive stars (long) and from mergers of compact objects (short). We present here the results of the temporal analysis of 42 GRBs detected with the Gamma-ray Burst Monitor onboard the Fermi Gamma-ray Space Telescope. We deconvolved the profiles into pulses, which we fit with lognormal functions. The distributions of the pulse shape parameters and intervals between neighboring pulses are distinct for both burst types and also fit with lognormal functions. We have studied the evolution of these parameters in different energy bands and found that they differ between long and short bursts. We discuss the implications of the differences in the temporal properties of long and short bursts within the framework of the internal shock model for GRB prompt emission.Comment: 38 pages, 11 figure

First narrow-band search for continuous gravitational waves from known pulsars in advanced detector data

Spinning neutron stars asymmetric with respect to their rotation axis are potential sources of continuous gravitational waves for ground-based interferometric detectors. In the case of known pulsars a fully coherent search, based on matched filtering, which uses the position and rotational parameters obtained from electromagnetic observations, can be carried out. Matched filtering maximizes the signalto- noise (SNR) ratio, but a large sensitivity loss is expected in case of even a very small mismatch between the assumed and the true signal parameters. For this reason, narrow-band analysis methods have been developed, allowing a fully coherent search for gravitational waves from known pulsars over a fraction of a hertz and several spin-down values. In this paper we describe a narrow-band search of 11 pulsars using data from Advanced LIGO’s first observing run. Although we have found several initial outliers, further studies show no significant evidence for the presence of a gravitational wave signal. Finally, we have placed upper limits on the signal strain amplitude lower than the spin-down limit for 5 of the 11 targets over the bands searched; in the case of J1813-1749 the spin-down limit has been beaten for the first time. For an additional 3 targets, the median upper limit across the search bands is below the spin-down limit. This is the most sensitive narrow-band search for continuous gravitational waves carried out so far