381 research outputs found

    Pavement maintenance procedures with and without milling materials

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    AbstractThis study evaluates maintenance treatment followed by different Districts of New Mexico Department of Transportation (NMDOT). In addition, two case studies on the use of old pavement materials, called the “millings”, in maintenance projects are reported. Based on this study, it is observed that none of the Districts have a written procedure for maintenance work. Rather Districts rely on the experience of the maintenance crew for conducting maintenance projects. All Districts prefer to use chip seal for maintenance irrespective of distress conditions of the pavements. Patching and crack sealing are usually done before chip sealing to extend the life of the chip seals. Sand seal, scrub seal, and slurry seal projects are not done by District maintenance crews but by outside contractors. It is also observed that all Districts are interested in using millings in maintenance projects and most have already used millings in at least one maintenance project with some success and failure. Most of the Districts have used coarse fraction of millings in chip seal projects successfully. However, they failed to find a proper way to process the fine fractions of millings. Case Study I shows that fine millings can be used to construct thin overlay when mixed with emulsion in pug mill or hot drums. Case Study II concludes that fine millings can be used as fine/sand seal successfully following the same procedure and using the same equipment as chip seal

    Methodology for Evaluation of Seal-Coated, Gravel, and Dirt Roads

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    The objective of this research project was to develop methodologies for the evaluation of different types of seal-coated, gravel, and dirt roads by using a best-practice-oriented pavement-management system in Illinois. A statewide survey comprised of 13 questions collected 133 responses from county engineers and highway commissioners. Many counties and townships in Illinois performed similar practices to maintain seal-coated, gravel, and dirt roads. The subjective windshield surveys were often conducted on a weekly basis to identify the most common distresses, such as potholes, rutting, and roadside drainage. Several seal-coated, gravel, and dirt roads were evaluated using a field distress-survey manual method based on the newly developed Seal-Coated Road Condition Index (SCRCI) and an Unsurfaced-Road Condition Index (URCI) that was adopted to measure surface conditions of gravel and dirt roads. In addition, some of the commercially available cell phone applications, or apps, were investigated for their effectiveness next to the use of a rolling or high-speed profilometer for assessing roughness conditions of seal-coated, gravel, and dirt roads in this research study. Future research is recommended to fully establish guidelines about the use of a cell phone app to be adopted by the Illinois Department of Transportation (IDOT) and for use by local agency officials in Illinois. In conclusion, this research project established a database to develop a best-practice guide for effectively evaluating unpaved roads maintained by local agencies.IDOT-R27-174Ope

    A Dual-Band Circularly Polarized Printed Antenna for Deep Space CubeSat Communication

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    This paper presents the design of a dual-band printed planar antenna for deep space CubeSat communications. The antenna system will be used with a radio for duplex operation in a CubeSat, which can be used for a lunar mission or any deep space mission. While a high-gain CubeSat planar antenna/array is always desired for a deep space mission, high-performance ground stations are also required for robust communication links. For such a mission, the X-band is the appropriate frequency for the downlink communication,which is very challenging in the case of deep space communication compared to the uplink communication. At this frequency, the antenna size can have small enough dimension to form an array to obtain high-gain directional radiations for the successful communication, including telemetry and data download. NASA’s Deep Space Network (DSN) has the largest and most sensitive 70 meter-diameter antenna that can be considered for this type of mission for reliability. DSN has uplink and downlink frequency of operations in 7.1-GHz and 8.4-GHz bands, respectively, which are separated by approximately 1.3 GHz. A straight forward approach is to use two antennas to cover uplink and downlink frequencies. However, CubeSats have huge space constraints to accommodate science instruments and other subsystems and commonly utilize outside faces for solar cells. Therefore, in this paper, we have proposed a planar directional circularly polarized antenna with a single feed that operates at both uplink and downlink DSN frequencies. Simulated 3-dB axial ratio bandwidth of 165MHz, from 7064MHz to 7229MHz for uplink, and that of 183MHz, from 8325 MHz to 8508 MHz for downlink, are achieved. Also, a wide impedance bandwidth of 23.86% (VSWR \u3c 2) is obtained. From this single probe-fed stacked patch antenna, peak RHCP gain of 9.24dBic can be achieved

    Small-Cell Installation in Transportation Infrastructure—A Literature Review

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    The purpose of this report is to provide information to the Illinois Department of Transportation (IDOT) on small-cell deployment on infrastructure such as light poles and traffic signals. A literature review was conducted on the technical specifications and impacts of small-cell deployment. The report explores the use of small-cell systems and potential hazards of small-cell deployment from an electromagnetic field perspective. A survey was conducted to gather information at a state and local level on current and future trends of small-cell deployment. The information gathered from the survey was combined from a standpoint of current best practices. The report provides recommendations for contractual obligations for both the department of transportation (DOT) and the small-cell provider. The report also provides guidelines on the best locations for small cells from a functional, structural, and aesthetic standpoint. The conclusion is that small-cell deployment is in our near future and the benefits of this technology are broad and mostly unexplored. While challenges exist, with proper contractual risk mitigation, both DOT entities and small-cell providers can reap benefits from the expansion of technology.IDOT-R27-SP41Ope

    The Impact of Technological and Marketing Innovations on Retailing Industry: Evidence of India

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    Innovation is usually linked with technology-based change. Retailers form a significant sector in the developed economies and also are picking up in the developing economies. There have been few studies in the area of innovation in the retail industry in both conceptual as well as empirical points of view. The objective of this study is to study the impact of marketing and technological innovations on the retail industry. The sample of the study was drawn from the customers who live in the city of Aligarh in India. The study is conclusive, descriptive and is based on a single cross-sectional research design. Quantitative data was generated on the basis of the research instrument (a questionnaire). The study concluded that technological innovation is more important than marketing innovation with respect to World of Mouth (WOM) referral and satisfaction. Furthermore, the study revealed that technological innovation has an impact on store image, customer value, brand store equity, satisfaction, WOM referral, and WOM activity. The study also recommended that a retailer can take some advantages of introducing new technologies. This means investing in technologies would help in increasing market share and competitiveness of the retail sector in the long-run

    Synthesis, Characterization and Bioactivities of Some Novel Oxovanadium(IV) Glycinato Complexes

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    The novel oxovanadium(IV) complexes, [VIVO(GlyH)(Gly)]+ClO4 - .H2O (1), [VIVO(GlyH)(Gly)]+NO3 - .H2O (2), [VIVO(GlyH)(Gly)]+CH3COO- .H2O (3) were synthesized and characterized by FT-IR, UV-Vis and 1H NMR spectroscopic measurements. The cumulative spectroscopic assessment envisaged that, the complexes adopt a square pyramidal structure, in which the two glycine ligands coordinate to vanadium(IV) center in bidentate fashions conforming a homoleptic structure. The amino nitrogen and a carboxylato oxygen atom coordinate the vanadium(IV) center from both sides making a five members chelate by each side. All the complexes are stable in amorphous state and in aerobic and anaerobic solution. Significantly, all the complexes have the antifungal activities against Aspergillus niger and Penicillium notatum but ineffective against Candida tropicalis. No antibacterial activity was observed for the complexes against tested bacteria and unfortunately, they were found cytotoxic against brine shrimp bioassay

    Resource Management of Mobile Communication System

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    To ensure good traffic handling, channel allocation is one of the important mobile communication resources for quality of service. Usually, three types of channel allocations are widely used: fixed channel allocation, borrowing radio channels from surrounding calls and dynamic channel allocations. In this paper instead conventional channel allocation schemes, we used call admission control (CAC) scheme to combat forced termination (FT). The analytical model of traffic handling in mobile cellular network is implemented by Markov chain; hence the profile of call blocking probability of newly originating call and FT is shown against the call arrival rate and the number of channels. Finally the impact of fading parameters of wireless channel on FT is also analyzed under Rayleigh fading case

    Yrast states and electromagnetic reduced transition properties of 122Te by means of interacting boson model-1

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    In this paper, the yrast states and the electric reduced transition probabilities B(E2) ? from gamma transition 8+ to 6+, 6+ to 4+, 4+ to 2+ and 2+ to 0+ states of neutron rich 122Te nucleus in the frame work of Interacting Boson Model-I (IBM-I) have carried out. The calculated results have been compared with the available experimental values. The ratio of the excitation energies of first 4+ and 2+ excited states (R4/2), have also been calculated for this nucleus. An acceptable degree of agreement between the predictions of IBM-I model and experiment is achieved. Moreover, as a measure to quantify evolution, we studied the transition rate R = B(E2 : L+ ? (L - 2)+) / B(E2 : 2+ ? 0+) of some of the low-lying quadrupole collective states in comparison to the available experimental data. The IBM-I formula for energy levels and the reduced transition probabilities B(E2) have been analytically deduced in the U(5) limit for a few yrast states transitions in 122Te isotope

    Heavy metals leaching behaviour assessment of palm oil clinker

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    Technical benefit of incorporation of Palm Oil Clinker (POC) in cement-based applications has been proven in recent studies. The aim of this work was to assess the heavy metal leaching behavior to ensure environmental safety of using POC in cement-based applications. The chemical composition, morphology, total organic carbon (TOC) and mineralogy were determined using XRF, FESEM, TOC analyzers and XRD to select appropriate chemical reagents for complete digestion. HNO3, HF and HClO4 were used for digestion of POC to measure heavy metal content using ICP-MS. The chemical reagents CH3COOH, NH2OH-HCl, H2O2+CH3COONH4 and HF+HNO3+HCl were used for extraction of acid soluble, reducible, oxidizable and residual fractions of heavy metals in POC, respectively. The leaching toxicity of the POC was investigated by the USEPA 1311 TCLP method. The result showed the presence of Be, V, Cr, Ni, Cu, Zn, As, Se, Ag, Cd, Ba and Pb with levels of 5.13, 11.02, 2.65, 1.93, 45.43, 11.84, 15.07, 0, 0, 81.97 and 1.76 mg/kg, respectively, in POC. The leaching value in mg/L of As (4.56), Cu(1.05), Be (0.89), Zn(0.51), Ba(0.26), Ni (0.17), V(0.15), Cr(0.001) and Se (0.001) is found well below the standard limit of risk. Risk assessment code (RAC) analysis confirms the safe incorporation of POC in cement-based applications
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