Walloch C.,ACM Chemistries Inc. |
Lang N.,Research and Development Laboratory |
Smith D.R.,Interlocking Concrete Pavement Institute ICPI
ASTM Special Technical Publication | Year: 2014
Concrete paving units are governed by ASTM C936/C936M, Standard Specification Solid Interlocking Concrete Paving Units. Regardless of size or configuration, these units are required to have a minimum average compressive strength of 55 MPa (8000 psi). This strength was originally established when ASTM C936 was first approved in 1982 based on concrete paving units having a thickness of 60 mm (2.36 in.) and a thickness/width aspect ratio of approximately 0.6. Prior to August 2012, the compressive strength testing procedures in ASTM C140, Standard Test Methods for Sampling and Testing Concrete Masonry Units and Related Units, did not include consideration for the configuration of the tested specimen. This produced results that could vary solely due to specimen configuration. Because of the proliferation of shapes and sizes of manufactured concrete paving units in recent years, research was conducted to determine the effect of specimen configuration on compressive strength. The research indicates that the aspect ratio of tested specimens affects the measured strength. The results were used to support revisions to the testing procedures to standardize the compressive strength specimen configuration and institute an "aspect ratio factor" used in calculating compressive strength. A separate research project evaluated the effect of variables in capping of compression test specimens. Capping is essential for providing consistent bearing surfaces for strength testing; however, the type of material and the thickness of the cap were found to have significant effects on strength. The results were used to justify limiting the capping material for pavers to high-strength gypsum, and limiting the cap thickness to 1.5 mm (0.06 in.). This paper reviews both projects and the changes to ASTM C140 based on the results. In addition, this paper presents a useful guide for testing laboratories so that they can readily understand and comply with the new compressive strength testing requirements. Copyright © 2014 by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959.
PubMed | Vietnam National University, Hanoi, Korea University, Duy Tan University, Chung - Ang University and Research and Development Laboratory
Type: Journal Article | Journal: BMC veterinary research | Year: 2016
Foot-and-mouth disease virus (FMDV) is one of the highest risk factors that affects the animal industry of the country. The virus causes production loss and high ratio mortality in young cloven-hoofed animals in Vietnam. The VP1 coding gene of 80 FMDV samples (66 samples of the serotype O and 14 samples of the serotype A) collected from endemic outbreaks during 2006-2014 were analyzed to investigate their phylogeny and genetic relationship with other available FMDVs globally.Phylogenetic analysis indicated that the serotype O strains were clustered into two distinct viral topotypes (the SEA and ME-SA), while the serotype A strains were all clustered into the genotype IX. Among the study strains, the amino acid sequence identities were shared at a level of 90.1-100, 92.9-100, and 92.8-100% for the topotypes SEA, ME-SA, and genotype IX, respectively. Substitutions leading to changes in the amino acid sequence, which are critical for the VP1 antigenic sites were also identified. Our results showed that the studied strains are most closely related to the recent FMDV isolates from Southeast Asian countries (Myanmar, Thailand, Cambodia, Malaysia, and Laos), but are distinct from the earlier FMDV isolates within the genotypes.This study provides important evidence of recent movement of FMDVs serotype O and A into Vietnam within the last decade and their genetic accumulation to be closely related to strains causing FMD in surrounding countries.
Salaga M.,Medical University of Lódz |
Polepally P.R.,University of Mississippi |
Sobczak M.,Medical University of Lódz |
Grzywacz D.,Research and Development Laboratory |
And 6 more authors.
Journal of Pharmacology and Experimental Therapeutics | Year: 2014
The opioid and cannabinoid systems play a crucial role in multiple physiological processes in the central nervous system and in the periphery. Selective opioid as well as cannabinoid (CB) receptor agonists exert a potent inhibitory action on gastrointestinal (GI) motility and pain. In this study, we examined (in vitro and in vivo) whether PR-38 (2-O-cinnamoylsalvinorin B), a novel analog of salvinorin A, can interact with both systems and demonstrate therapeutic effects. We used mouse models of hypermotility, diarrhea, and abdominal pain. We also assessed the influence of PR-38 on the central nervous system by measurement of motoric parameters and exploratory behaviors in mice. Subsequently, we investigated the pharmacokinetics of PR-38 in mouse blood samples after intraperitoneal and oral administration. PR-38 significantly inhibited mouse colonic motility in vitro and in vivo. Administration of PR-38 significantly prolonged the whole GI transit time, and this effect was mediated by μ- and κ-opioid receptors and the CB1 receptor. PR-38 reversed hypermotility and reduced pain in mouse models mimicking functional GI disorders. These data expand our understanding of the interactions between opioid and cannabinoid systems and their functions in the GI tract. We also provide a novel framework for the development of future potential treatments of functional GI disorders. Copyright © 2014 by The American Society for Pharmacology and Experimental Therapeutics.
Lang N.R.,Research and Development Laboratory |
Thompson J.J.,National Concrete Masonry Association
ASTM Special Technical Publication | Year: 2014
Many of the physical requirements for concrete masonry units (CMU) contained in ASTM C90, Standard Specification for Concrete Masonry Units, had remained unchanged for many years. The requirements for web thickness, for example, were introduced in the 1950s, representing the best practices for production at that time. These requirements remained essentially unchanged until 2011 when significant changes were incorporated. With a changing environment for building requirements, especially those related to energy efficiency and sustainability, the need for the concrete masonry unit to evolve has become evident. In late 2011, the minimum web requirements in ASTM C90 were significantly revised to provide new flexibility in CMU unit design/configuration. These changes, based on a rational review of the factors that affect minimum web thickness, provide CMU producers, specifiers, and contractors with means to adjust unit configurations to meet the needs of their market. Additionally, as a result of research performed by the National Concrete Masonry Association on CMU prism strengths, the minimum compressive strength required by ASTM C90 was increased from 1900 psi (13.1 MPa) to 2000 psi (13.8 MPa). This change, coupled with revisions to the unit strength method for determining compliance with the specified compressive strength of masonry [see TMS 602/ACI 530.1/ASCE 6, 2011, "Specification for Masonry Structures," Masonry Standards Joint Committee, Longmont, CO] can provide more economical designs and cost-competitive construction. These changes are significant revisions to this specification, and the potential impact to the industry is large. This paper reviews these changes to ASTM C90, the rationale supporting the changes, and the impacts to the concrete masonry industry and concrete masonry construction. Copyright © 2014 by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959.
Demirkiran H.,Research and Development Laboratory
Advances in experimental medicine and biology | Year: 2012
The remarkable need for bone tissue replacement in clinical situations, its limited availability and some major drawbacks of autologous (from the patient) and allogeneic (from a donor) bone grafts are driving researchers to search for alternative approaches for bone repair. In order to develop an appropriate bone substitute, one should understand bone structure and properties and its growth, which will guide researchers to select the optimal conditions for tissue culture and implantation. It's well accepted that bioceramics are excellent candidates as bone replacement with osteogenesis, osteoinduction and osteoconduction capacity. Therefore, the molecular and cellular interactions that take place at the surface of bioceramics and their relevance in osteogenesis excites many researchers to delve deeper into this line of research.
Shestopaloff Y.K.,Research and Development Laboratory
Biophysical Reviews and Letters | Year: 2015
We consider a general growth mechanism, which acts at cellular level and above (organs, systems and whole organisms). Using its mathematical representation, the growth equation, we study the growth and division mechanisms of amoeba and fission yeast Schizosaccharomyces pombe. We show how this mechanism, together with biomolecular machinery, governs growth and reproduction of cells, and these organisms in particular. This mechanism provides revealing answers to fundamental questions of biology, like why cells grow and divide, why and when cells' growth stops. It also sheds light on questions like why and how life originated and developed. Solving the growth equation, we obtain analytical expression for the growth curve of fission yeast as a function of geometrical characteristics and nutrient influxes for RNA and protein synthesis, and compare the computed growth curves with 85 experiments. Statistical evaluation shows that these growth curves correspond to experimental data significantly better than all previous approximations. Also, using the general growth mechanism, we show how metabolic characteristics of cells, their size and evolutionary traits relate, considering fission yeast. In particular, we found that fission yeast S. pombe consumes about 16-18 times more nutrients for maintenance needs than for biomass synthesis. © 2015 World Scientific Publishing Company.
Anithambigai P.,Universiti Sains Malaysia |
Dinash K.,Universiti Sains Malaysia |
Mutharasu D.,Universiti Sains Malaysia |
Shanmugan S.,Universiti Sains Malaysia |
Lim C.K.,Research and Development Laboratory
Thermochimica Acta | Year: 2011
Thermal transient measurement based on structure function evaluation was used to measure the thermal resistance. The study signifies the importance of dual interface method in determining the exact point of separation between the board and the LED package. For a constant ambient temperature which was maintained at 28.2 ± 1.0 °C at 700 mA, the junction to board thermal resistance obtained was 10.84 K/W. In addition, an experimental set up has been reported in this work having a constant water flow beneath the external heat sink. More emphasis has been given in studying the effect of change of such measurement environment on the junction to board thermal resistance. It was revealed that the junction to board thermal resistance was not affected but the total real thermal resistance from junction to ambient was reduced significantly by 55.6% upon cooling with water. A study on the effect of light output on the total thermal resistance was performed and it was revealed that the efficiency and the reliability of an LED are strongly dependent on the optical properties of the device. © 2011 Elsevier B.V. All rights reserved.
El Gouri M.,Université Ibn Tofail |
Cherkaoui O.,Research and Development Laboratory |
Ziraoui R.,Université Ibn Tofail |
El Harfi A.,Université Ibn Tofail
Journal of Materials and Environmental Science | Year: 2010
In the present research, we have investigated the analysis of gases generated under thermal decomposition of neat and flame retarded DGEBA epoxy resin based on HGCP (Hexaglycidyl cyclotriphosphazene). The use of thermogravimetry coupled with Fourier transform infrared spectroscopy (TG-FTIR) has allowed the continuous detection of a number of the most important fire gases. The morphology of samples during thermal degradation have been observed by way of scanning electron microscopy (SEM) coupled with Energy Dispersive X-ray (EDX) analysis. We have shown that 5% add-on of HGCP can impart DGEBA UL94 V-0 rating. IR data and thermal decomposition data show that HGCP accelerates the emission of the inflammable gas and char forming of DGEBA. In addition, SEM pictures indicate that HGCP promotes foaming and char expansion, and improve gullys on char surface as well. All these fact were helpful to combine the gas action and the condensed phase action (intumescent) for HGCP flame retardancy.
Fiorentino G.,Research and Development Laboratory |
Corsi A.,Research and Development Laboratory |
Fragnito P.,Research and Development Laboratory
e-Energy 2015 - Proceedings of the 2015 ACM 6th International Conference on Future Energy Systems | Year: 2015
The increasing share of electricity generation from renewable sources creates several issues on power electricity system especially as regards demand and generation balance. In order to maintain power system stable new framework are now available. On key idea is based upon the participation on demand side management of smart and intelligent appliances as flexibility providers. The high penetration of intelligent appliances turns the whole buildings into effective and efficient prosumers. These distributed and autonomous intelligent Commercial Prosumer Hubs, constituted of Distributed Energy Resources clusters raising an actual decentralized Demand Side Management, behave like Smart Virtual Power Plants that an aggregator can manages using a portfolio of commercial buildings composed of flexible device to deliver services to the electricity grid. This new infrastructure maximizes the response capacity of the vast, small-commercial prosumer base (e.g., tertiary buildings, offices, etc.), presenting incentives and delivering benefits through their automated active participation in the energy market, aligning consumption by asking consumers to reduce their power usage rather than increasing the power generation facilities. Under this approach, prosumers that cooperate might receive incentive payments from the power company. In this respect, an overlay smart network for efficient grid control, running on top of the existing energy grid and incorporating high levels of distributed intelligence within autonomous and semantically enhanced Prosumer Hubs will bring to the new concept of Internet of Energy through widespread use of smart devices, bi-directional communication and proper software infrastructure. © 2015 ACM.
Shestopaloff Y.K.,Research and Development Laboratory
International Journal of Electronics | Year: 2011
The article considers a parametric effect which takes place when the velocity of signal propagation in a long line changes. We found the analytical solution describing the form of the transformed signal for a line with losses, when line parameters change symmetrically. We also considered lines without losses, with asymmetrical change of parameters. Our theoretical results comply with experimental data. In certain conditions, such a line can be used as an amplifier. The parametric effect in optics is described by Maxwell's equations, while in case of a long line, the analysis is based on telegrapher's equations. However, it turns out that in the end, both in optics and electronics, the parametric effect is described by wave equations that are mathematically similar. This is because fundamentally, when the parameters of the propagating medium change, the parametric effect is physically based on energy interchange between the controlling (pump) signal and the transformed one. So, the obtained results can be used for analysis of parametric effects in optics and electronics. © 2011 Taylor & Francis.