Significant Penetration Research Articles

Explanation of penetration depth variation during laser welding under variable ambient pressure

It has been observed that the penetration depth during laser welding (LW) under vacuum or reduced ambient pressure could be significantly greater than that during welding under atmospheric pressure. Previous explanations of this phenomenon usually limit to specific wavelength laser welding and have difficulties in explaining why the variation will disappear, as the welding speed increases. Here, we propose that this variation is caused by the temperature difference of keyhole wall under variable ambient pressure based on a correct physical description of related processes. A new surface pressure model, dependent on ambient pressure, is proposed for describing the evaporation process during laser material interaction under variable ambient pressure. For laser welding of a 304 stainless steel with 2.0 kW laser power and 3 m/min welding speed, it is shown that the average keyhole wall temperature is around 2900 K under atmospheric pressure, and only around 2300 K under vacuum, which results in significant penetration depth variations. Interestingly, it is also shown that as the welding speed increases, the average temperature of the front keyhole wall gradually rises due to the reduction of the mean incident angle of laser, and the magnitude of this increase is larger in welding under vacuum than under atmospheric pressure. It allows us to explain why the penetration depth improvement decreases to zero with the increase of welding speed.

Game-Theoretic Frameworks for Demand Response in Electricity Markets

This paper presents game-theoretic frameworks for demand response at both electricity market and consumer levels. First, the interaction between a demand response aggregator (DRA) and electricity generators is modeled as a Stackelberg game in which the DRA, as the leader of the game, makes demand reduction bids, and generators, as followers, compete for maximizing their profits based on the reduced demand. Next, the interaction between the DRA and consumers is modeled as a mechanism design problem wherein the DRA seeks to minimize the aggregate inconvenience of consumers while achieving the targeted load curtailment. The inconvenience function of each consumer is captured by a type value, which is used by the DRA to solve the load curtailment problem. A Vickrey-Clarke-Groves-based mechanism is proposed, which guarantees that each consumer reveals its true type value to the DRA. A case study of the Stackelberg game shows that, in the South Australian electricity market where there is significant renewable penetration, peak period demand response provides the maximum potential profit, but off-peak demand response even in a concentrated market is not financially attractive.

An Integrated Controllable Network Transformer—Hybrid Active Filter System

Dynamic control over real and reactive power flow is one of the key areas of concern for the modern grid. Traditional FACTS-based devices have proven to be too costly and complex to achieve any significant market penetration. Modifying existing transmission assets to make them controllable may be a cost-effective method of increasing the grid controllability. Controllable network transformers (CNTs) have been theoretically shown to be an effective real and reactive power flow controller. However, the CNT is shown to produce unwanted third harmonic voltages and currents in the system, which must be handled. In this paper, the use of a hybrid active filter (HAF) is proposed for this purpose. This paper discusses the approach for design and control of such an integrated CNT-HAF system. It is shown that the integrated CNT-HAF system can also mitigate system unbalance, apart from providing four-quadrant control capability. Furthermore, this paper also presents experimental results of an integrated CNT-HAF system, rated at 200 kVA and 2400 V.

The heavy-duty vehicle future in the United States: A parametric analysis of technology and policy tradeoffs

We present a parametric analysis of factors that can influence advanced fuel and technology deployments in U.S. Class 7–8 trucks through 2050. The analysis focuses on the competition between traditional diesel trucks, natural gas vehicles (NGVs), and ultra-efficient powertrains. Underlying the study is a vehicle choice and stock model of the U.S. heavy-duty vehicle market. The model is segmented by vehicle class, body type, powertrain, fleet size, and operational type. We find that conventional diesel trucks will dominate the market through 2050, but NGVs could have significant market penetration depending on key technological and economic uncertainties. Compressed natural gas trucks conducting urban trips in fleets that can support private infrastructure are economically viable now and will continue to gain market share. Ultra-efficient diesel trucks, exemplified by the U.S. Department of Energy's SuperTruck program, are the preferred alternative in the long haul segment, but could compete with liquefied natural gas (LNG) trucks if the fuel price differential between LNG and diesel increases. However, the greatest impact in reducing petroleum consumption and pollutant emissions is had by investing in efficiency technologies that benefit all powertrains, especially the conventional diesels that comprise the majority of the stock, instead of incentivizing specific alternatives.

Identification and characterization of ML352: a novel, noncompetitive inhibitor of the presynaptic choline transporter.

The high-affinity choline transporter (CHT) is the rate-limiting determinant of acetylcholine (ACh) synthesis, yet the transporter remains a largely undeveloped target for the detection and manipulation of synaptic cholinergic signaling. To expand CHT pharmacology, we pursued a high-throughput screen for novel CHT-targeted small molecules based on the electrogenic properties of transporter-mediated choline transport. In this effort, we identified five novel, structural classes of CHT-specific inhibitors. Chemical diversification and functional analysis of one of these classes identified ML352 as a high-affinity (Ki = 92 nM) and selective CHT inhibitor. At concentrations that fully antagonized CHT in transfected cells and nerve terminal preparations, ML352 exhibited no inhibition of acetylcholinesterase (AChE) or cholineacetyltransferase (ChAT) and also lacked activity at dopamine, serotonin, and norepinephrine transporters, as well as many receptors and ion channels. ML352 exhibited noncompetitive choline uptake inhibition in intact cells and synaptosomes and reduced the apparent density of hemicholinium-3 (HC-3) binding sites in membrane assays, suggesting allosteric transporter interactions. Pharmacokinetic studies revealed limited in vitro metabolism and significant CNS penetration, with features predicting rapid clearance. ML352 represents a novel, potent, and specific tool for the manipulation of CHT, providing a possible platform for the development of cholinergic imaging and therapeutic agents.

Indium penetration through thermally grown silicon oxide

Indium penetration through silicon oxide was investigated using thermal oxides capped with polycrystalline silicon. When indium was implanted into the silicon substrate, indium penetrated through a thin oxide into the polycrystalline silicon at low temperatures. The amount of indium penetration was determined by the transient enhance diffusion of indium in silicon. Significant indium penetration was also observed in samples with indium implantation in a thick oxide. The redistribution of indium in the oxide layer controlled the penetration behavior. Such evidence indicates that thermal oxide cannot be used as a diffusion barrier for indium. Diffusion parameters for indium in polycrystalline silicon were extracted according the indium penetration profiles. The activation energy for indium diffusion in polycrystalline silicon is around 2.5 eV, which is lower than that in silicon. However, the indium diffusion in polycrystalline silicon was reduced when the thermal oxide under the polycrystalline silicon layer became thicker.

Brave New World

Sophisticated mobile computing, sensing and recording devices are commonplace. Smart phones have achieved significant penetration and novel devices like Google Glass are imminent. These devices can serve most functions of a conventional notebook computer, but also have a range of additional capabilities, including image/audio/video recording, GPS location, compass, accelerometer, nearrange radio (NFC and Bluetooth), and soon health and fitness monitors. Moreover, these devices are carried by their users virtually around the clock, blurring the distinction between the online and offline world and enabling transformative new applications and services. For instance, mobile apps can provide location and activity-sensitive services and information, in the case of Google Glass overlaid right onto a user’s field of view. They can record what the user does, sees and hears for future reference; and they can keep track of a user’s encounters with nearby users’ devices to enable communication related to a shared experience or event. However, these applications and services also introduce a range of new threats to users’ privacy. While a user carries it, a mobile device can capture a complete record of the user’s location, online and offline activities, and social encounters, potentially including an audio-visual record. While such a record is very useful to a user for their own reference and to enable new applications, it is also highly sensitive and inherently private. Unlike information users post on Facebook or Twitter, most users would likely not want to share such a comprehensive record with anyone. In this paper, we catalog privacy threats introduced by these devices and applications. Our survey of threats underlines how privacy threats from mobile devices are fundamentally different and inherently more dangerous than in prior systems. For each specific risk vector, we describe technical challenges that, if solved, can mitigate its effects. We note that technical innovations merely provide a starting point: an end-to-end privacy-preserving infrastructure will require changes in how basic services are deployed, how laws

Leveraging Big Data for the Development of Transport Sustainability Indicators

While increasing transportation sustainability is an ongoing effort, measuring the results of these efforts is not a trivial task. Not only is indicator selection challenging, but efforts made to design useful indicators are often hampered by the presence of erroneous or incomplete data. Nevertheless, in this era of Big Data, the significant penetration of new technologies such as smartphones and smart infrastructure could hold the key to developing more relevant and comprehensive indicators. Here, we recall commonly used indicators and discuss the limitations of the data upon which they are built. We then describe several new technologies that hold promise for collection of more pertinent and accurate data sets for indicator development. Finally, we illustrate potential benefits and concerns of these approaches via discussion of possible indicator development from a one-day GPS trace. While the first and obvious application of new technologies will be to improve much needed accuracy, successfully combining different sources together could hold much potential from model calibration to real-time operations.

Delivery of Liposomal Contents to Outer Membrane Vesicles from Gram Negative Bacteria

Gram negative bacteria produce small ∼50-200 nm vesicles from their outer membranes. These outer membrane vesicles (OMV) have been implicated in activities such as transmission of virulence factors, horizontal gene transfer and development of biofilms. In this investigation, we continue our studies on the association and/or fusion of various liposomes with OMV. The delivery of large encapsulated molecules into OMV from L. enzymogenes C3 was investigated using liposomes with lipid compositions previously observed to be apparently fusogenic (Bartos et al., Biophys. J. 104(2) suppl1, 90a). Liposomes (100 nm) composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-(1′-rac-glycerol) (POPG) and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine (POPE) in a 1:3 ratio or 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) were used to encapsulate dextran conjugates of Texas red averaging 40 kDa. They were incubated with Lysobacter OMV (30°C, 1 hr.), then sedimented through 15% iodixanol, and the fluorescence monitored as indicatiive of transfer of liposomal contents to fused products. Both liposomal compositions showed significant evidence of dextran transfer. Because biofilms also contain OMV, the interaction of these liposomes with E. coli (DH10B) biofilms was also investigated via fluorescence microscopy. Significant penetration and binding within the biofilm mass was observed, as well as possible fusion with OMV, and rarely, evidence of transfer of dextran into whole bacterial cells. Fluorescence resonance energy transfer (FRET)-based assays also demonstrated that liposomes as small as 30 nm could rapidly fuse with Lysobacter OMV, suggesting possible delivery to OMV with smaller perturbation and better biofilm penetration.

Marginal Seal of Water-Based Formulation of Light Activated Bonding Agent for Use in Combination with Adhesive Restorations

Aim: The purpose of the study was to investigate effect of water-based solvent adhesive system on micro-leakage of composite resinrestorations. Materials and methods: Class V cavities were prepared on buccal and lingual surfaces of 20 human molars, The occlusal margins were prepared in enamel while cervical ones were prepared in dentin below CEJ by one mm, and classified into four groups according to type of adhesive used five teeth each: Adper Single Bond2 was used as control, Clearfil SE Bond water-based adhesive, Clearfil S3 Bond ethanol-based adhesive, I-Bond acetone-based adhesive. All cavities were restored with Filtek Z250 composite, stored in distilled water at 37?C for 24 hours and thermal cycled. All surfaces, except for restorations and 1 mm from the margins, were coated with two layers of nail varnish. The teeth were immersed in a 3% methylene blue dye solution for 24 hours, and then rinsed in running water, blot-dried and sectioned longitudinally through center of restorations from the facial to lingual surface. The sections (10 sections for each group by n=20 readings) were blindly assessed for microleakage of dye penetration for both the occlusal and gingival margins. Data were collected and statistically analyzed. Results: Results demonstrate a comparable significantly lesser mean dye penetration in Adper single Bond2 adhesive than in other groups at enamelmargins (p<0.05) and a highly significant lesser mean dye penetration at dentin margins. Clearfil SE Bond water-based adhesive showed a significant higher mean value of dye penetration at dentin margins than either ethanol or acetone-based adhesives and a comparable non significantly lesser mean dye penetration score at enamel margins. Conclusion: Clearfil SE Bond (water-based adhesive) showed a significant higher mean value of dye penetration score at dentin margins than either ethanol or acetone-based adhesives.

Effect of Fruit Size and Processing Time on Vacuum Impregnation Parameters of Cantaloupe and Apple

This study evaluated the effect of two fruit sizes (3.5×2.5×1.0 and 1.2×1.2×0.8 cm 3 ) and processing time (impregnation and relaxation times; both for 10 and 20 min), on some vacuum impregnation parameters of cantaloupe and apple. Fruit size and processing time significantly affected the mass fraction of fruit occupied by impregnation liquid (X value) and the effective porosity (ee) of apples more than cantaloupe. High surface area of fruit and long processing times allowed for significant liquid penetration into the fruit. This study has shown that the effectiveness of vacuum impregnation is a surface-controlled phenomenon.

A Three Phase Power Flow Algorithm for Distribution Network Incorporating the Impact of Distributed Generation Models

The significant penetration of Distributed Generation(DG) systems in electrical power industry is mainly driven by the ever increasing demand for electrical power and growing environmental concerns. Power Flow Studies play a vital role in planning the future expansion of power system as well as for deciding the optimum operation of the existing power system. The ill conditioned nature of distribution system as well as unbalanced nature of DG sources demand unbalanced power flow studies for analysing the DG integrated distribution system. For the power flow studies, DGs can be modelled as either PQ or PV nodes based on the type and interconnection method to the grid. The paper presents an unbalanced power flow algorithm based on the current summation method for the distribution system with the DGs modelled either as PQ or PV node. Handling of PV nodes is done with the help of the sensitivity impedance matrix. The proposed algorithm is validated with IEEE 13 bus distribution feeder

Enhanced Mixing in Supersonic Flow Using a Pulse Detonator

Mixing enhancement in a crossflow using the transient high-pressure, high-temperature, and high-velocity pulse from a detonation was investigated experimentally. High-frame-rate shadowgraphy and planar laser-induced fluorescence of the nitric oxide molecule showed the structure and time-dependent interaction of the detonation plume with the supersonic flow. The high-momentum flux from the detonation provided significant penetration, with blowdown times of 4–8 ms achieved. Planar laser-induced fluorescence of nitric oxide captured the spanwise structure of the plume and the large counter-rotating vortex structure for enhanced mixing. The upstream jet was shown to be drawn into the pulse detonator’s plume, providing distribution to the core supersonic flow. Significant coupling between a continuous upstream jet and the pulse detonator plume was found and indicated that there was an optimal staging distance for enhanced mixing.

A risk score to predict the difficulty of elective laparoscopic cholecystectomy.

IntroductionSeveral preoperative scoring systems have been proposed to predict the difficulty of laparoscopic cholecystectomy in order to optimize the results of surgical treatment by either selection of patients for the procedure or providing an adequately experienced surgical team for a given patient. Nevertheless, none of them has achieved significant penetration into everyday practice.AimTo propose and validate a novel risk score based on the patient's history, physical examination and abdominal ultrasonography parameters.Material and methodsThe risk score was defined by the presence of the following risk factors: male sex, biliary colic within the last 3 weeks prior to surgery, history of acute cholecystitis treated conservatively, previous upper abdominal surgery, right upper quadrant pain, rigidity in right upper abdomen and ultrasonographic parameters – thickening of the gallbladder wall ≥ 4 mm, hydropic gallbladder (diameter exceeding 4.5 cm) and shrunken gallbladder. One point was allocated for each risk factor, except for previous upper abdominal surgery, which scored two. Difficulty of the surgery was assessed by operating time (OT) and the postoperative subjective evaluation score (PSES).ResultsFive hundred and eighty-six consecutive patients were enrolled in the prospective observational study. A significant linear correlation was observed between the risk score and measures of difficulty employed. Five levels of difficulty were defined (score 0, 1, 2, 3, ≥ 4) with significant differences in OT, PSES and conversion rates (p < 0.001).ConclusionsThe suggested risk score is designed as a simple and reliable predictive model, possibly effective to overcome the negative effect of the individual proficiency gain curve and/or to select ‘easy’ cases for day surgery, single incision laparoscopic surgery or natural orifice translumenal endoscopic surgery procedures.

Steric Inhibition of Metal Penetration in the Fabrication of Metal/Molecule Contacts

Tunneling spectroscopy was used to characterize a series of junctions with para-substituted (SH, F, Cl, Br, and I) benzoic acid monolayers positioned between aluminum/aluminum oxide surfaces and Pb electrodes. The tunneling conductance spectra revealed several effects that can be attributed to the size and reactivity of the para-substituent. First, as the size of the halogen substituent increased from fluoro to iodo, the extent of Pb penetration through the monolayer to the substrate was diminished. The extent of penetration was observed as a shift in the conductance minimum toward higher bias voltage. In the case of the 4-fluoro substituent, there was significant penetration of Pb to the bottom interface, and the conductance minimum was observed near 140 mV. In the case of the 4-iodo substituent, there was minimal Pb penetration, and the conductance minimum was ∼20 mV. Second, when the para-substituent was a thiol group, the deposition of lead results in Pb–S bond formation, which was confirmed by the absence of the S–H stretching mode in inelastic tunneling spectroscopy. The effect of Pb–S bond formation was to inhibit Pb penetration and invert the barrier height, which resulted in a shift in the minimum conductance to a negative bias. These results highlight the importance of tunneling spectroscopy to better understand contacting details at the metal–molecule interface.

Electric vehicles’ energy consumption measurement and estimation

Use of electric vehicles (EVs) has been viewed by many as a way to significantly reduce oil dependence, operate vehicles more efficiently, and reduce carbon emissions. Due to the potential benefits of EVs, the federal and local governments have allocated considerable funding and taken a number of legislative and regulatory steps to promote EV deployment and adoption. With this momentum, it is not difficult to see that in the near future EVs could gain a significant market penetration, particularly in densely populated urban areas with systemic air quality problems. We will soon face one of the biggest challenges: how to improve efficiency for EV transportation system? This research takes the first step in tackling this challenge by addressing a fundamental issue, i.e. how to measure and estimate EVs’ energy consumption. In detail, this paper first presents a system which can collect in-use EV data and vehicle driving data. This system then has been installed in an EV conversion vehicle built in this research as a test vehicle. Approximately 5months of EV data have been collected and these data have been used to analyze both EV performance and driver behaviors. The analysis shows that the EV is more efficient when driving on in-city routes than driving on freeway routes. Further investigation of this particular EV driver’s route choice behavior indicates that the EV user tries to balance the trade-off between travel time and energy consumption. Although more data are needed in order to generalize this finding, this observation could be important and might bring changes to the traffic assignment for future transportation system with a significant share of EVs. Additionally, this research analyzes the relationships among the EV’s power, the vehicle’s velocity, acceleration, and the roadway grade. Based on the analysis results, this paper further proposes an analytical EV power estimation model. The evaluation results using the test vehicle show that the proposed model can successfully estimate EV’s instantaneous power and trip energy consumption. Future research will focus on applying the proposed EV power estimation model to improve EVs’ energy efficiency.

AI-25 * THE NOVEL c-MET INHIBITOR ALTIRATINIB (DCC-2701) INHIBITS TUMOR GROWTH AND INVASION IN A BEVACIZUMAB RESISTANT GLIOBLASTOMA MOUSE MODEL

Glioblastoma with acquired resistance to bevacizumab therapy overexpresses c-MET which mediates tumor growth, EMT, invasion, and metastasis. We evaluated the expression level of total and phosphorylated c-MET (p-c-MET) and the inhibitory activity of altiratinib (DCC-2701), a novel c-MET/TIE2/VEGFR inhibitor (Deciphera Pharmaceuticals) that has demonstrated significant BBB penetration into the CNS. Four of 12 (30%) mesenchymal glioma stem cell lines (GSCs) highly expressed c-Met and were sensitive to altiratinib treatment in vitro for blocking cell viability. After HGF stimulation, the expression level of p-cMET was significantly increased in these 4 cell lines. Altiratinib markedly suppressed HGF stimulated p-c-MET expression in both paracrine (MET+) and autocrine (MET + /HGF+) GSC cell lines. In an intracranial glioma mouse model, animals were treated with bevacizumab (Bev) alone, altiratinib alone or the combination. Mice were euthanized at 3, 4 and 5 weeks. H&E staining revealed a significant reduction in tumor size in the combination group compared with the tumors treated with either agent alone. Altiratinib alone or combination with Bev treatment dramatically suppressed EMT and tumor invasion in vivo. This anti-invasive effect correlated with decreased N-cadherin and vimentin levels. In vivo, microvascular density was significantly inhibited in the groups treated with altiratinib and altiratinib plus Bev compared with control or the group treated with Bev alone. Similarly, F4/80+ BMDC cell infiltration was significantly suppressed in the groups treated with altiratinib and altiratinib plus Bev combination compared to control Bev-treated groups. In summary, our data indicated that altiratinib inhibited tumor growth, EMT and invasion both in vitro and in vivo. The combination of altiratinib and anti-VEGF therapy may provide a new strategy to overcome Bev resistance and prolong overall survival in patients with glioblastoma.

Cost-of-Service Segmentation of Energy Consumers

Uncertainty in consumption is a key challenge at energy utility companies, which are faced with balancing highly stochastic demand with increasingly volatile supply characterized by significant penetration rates of intermittent renewable sources. This paper proposes a methodology to quantify uncertainty in consumption that highlights the dependence of the cost-of-service with volatility in demand. We use a large and rich dataset of consumption time series to provide evidence that there is a substantial degree of high-level structure in the statistics of consumption across users which may be partially explained by certain characteristics of the users. To uncover this structure, we propose a new technique for extracting typical statistical signatures of consumption-energy demand distributions (EDDs)-that is based on clustering distributions using a fast, approximated algorithm. We next study the factors influencing the choice of consumption signature and identify certain types of appliances and behaviors related to appliance operation that are most predictive. Finally, we comment on how structure in consumption statistics may be used to target residential energy efficiency programs to achieve greatest impact in curtailing cost of service.

FTIR spectroscopy of woods: A new approach to study the weathering of the carving face of a sculpture

Fourier transform infrared spectroscopy (FTIR), a useful method to study woods, has been applied in order to measure an eventual gradient of water absorbed (more precisely, hydroxyl groups, OH) between the surface and the inner part of an ancient and a modern wooden sculptures. The methodology adopted has consisted in comparing FTIR bands within two spectral ranges, one corresponding to the OH content in the wood (around 3400cm−1) and the other to the lignin molecules (aromatic CC, around 1610cm−1). The ratio between the intensities of the peaks leads to a self-normalization of the measurements which avoids the effects of some experimental parameters (such as sample preparation).The results obtained show that there is a significant and progressive penetration of OH groups from the surface to the inside part of the ancient sculpture (more OH on the surface than inside the wood, due to the aging of the surface and the creation of sites which are able to fix OH groups). In contrary, for the modern one, we measure an increase of OH contents from the surface to the inner part of the sculpture.

Anti-platelet agents augment cisplatin nanoparticle cytotoxicity by enhancing tumor vasculature permeability and drug delivery

Tumor vasculature is critically dependent on platelet mediated hemostasis and disruption of the same can augment delivery of nano-formulation based chemotherapeutic agents which depend on enhanced permeability and retention for tumor penetration. Here, we evaluated the role of Clopidogrel, a well-known inhibitor of platelet aggregation, in potentiating the tumor cytotoxicity of cisplatin nano-formulation in a murine breast cancer model. In vivo studies in murine syngeneic 4T1 breast cancer model showed a significant greater penetration of macromolecular fluorescent nanoparticles after clopidogrel pretreatment. Compared to self-assembling cisplatin nanoparticles (SACNs), combination therapy with clopidogrel and SACN was associated with a 4 fold greater delivery of cisplatin to tumor tissue and a greater reduction in tumor growth as well as higher survival rate. Clopidogrel enhances therapeutic efficiency of novel cisplatin based nano-formulations agents by increasing tumor drug delivery and can be used as a potential targeting agent for novel nano-formulation based chemotherapeutics.