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Sample records for binary ethosome prepared

  1. Ethosomes as novel vesicular carrier: An overview of the principle, preparation and its applications.

    Science.gov (United States)

    Das, Sanjoy Kumar; Chakraborty, Soumalya; Roy, Chhandita; Rajabalaya, Rajan; Mohaimin, Amal Widaad; Khanam, Jasmina; Nanda, Arunabha; David, Sheba R

    2018-01-15

    In the study of lipid vesicular carriers in permeation enhancement of drug molecules across skin after the success story of liposomes, ethosomes are a recent addition. There are a number of published reviews but still, there is a lack of reviews representing various aspects in a systematic way with a detailed description of current research works. This review serves to fill this deficiency along with a special emphasize on its preparation methods and application. Information was collected from previously published literatures which were represented after analysis in terms of various aspects such as principles, composition, preparation, mechanism of penetration, modified forms, characterization, marketed preparation and its application. This review is represented in an informative and easily understandable way. Basic principles and background of exploring were covered in the introduction section. Composition section contains the basic components of formulations along with the impact of various parameters on the characterization of the ethosome. A detailed discussion of all the methods along with their own utility is elaborately discussed. Various aspects of characterization of ethosomes are also discussed. Therapeutic and cosmetic applications of ethosomes are also outlined here. In spite of having a potent permeation enhancing and targeted drug release profile ethosome suffers from limited commercialization. Various challenges regarding its commercialization and product development are also discussed in this review with an objective of acting as a directional route for the researchers. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  2. Effect of preparation technique on the properties and in vivo efficacy of benzocaine-loaded ethosomes.

    Science.gov (United States)

    Maestrelli, Francesca; Capasso, Gaetano; González-Rodríguez, Maria L; Rabasco, Antonio M; Ghelardini, Carla; Mura, Paola

    2009-01-01

    This study aimed to investigate the influence of the preparation conditions on the performance of an ethosomal formulation for topical delivery of the local anesthetic agent, benzocaine (BZC). Ethosomes were prepared with different techniques, such as thin-layer evaporation, freezing and thawing, reverse-phase evaporation, extrusion and sonication, obtaining, respectively, multilayer vesicles (MLVs), frozen and thawed MLV (FATMLV), large unilamellar vesicles (LUVs), and small unilamellar vesicles (SUVs). The obtained vesicles were characterized for morphology, size, zeta potential, and entrapment efficiency (EE%), and their stability was monitored during storage at 4 degrees C. In vitro permeation properties from gels incorporating drug ethosomal dispersions were evaluated in vitro by using artificial lipophilic membranes, while their anesthetic effect was determined in vivo on rabbits. The results suggested that the vesicle preparation method plays an important role in affecting the properties and effectiveness of ethosomal formulations. MLVs and LUVs exhibited higher drug EE% and better stability than FATMLV and SUV vesicles. The In vitro drug permeation rate was directly related to the vesicle EE% and varied in the order MLV>LUV approximately FATMLV>SUV. The therapeutic efficacy of BZC ethosomal formulations was significantly improved with respect to the corresponding BZC solution. The best results, in terms of enhanced intensity of anesthetic effect, were given by formulations containing MLVs and LUVs, and the order of effectiveness was MLV approximately LUV>FATMLV approximately SUV, rather similar to that found in permeation studies. On the contrary, unexpectedly, the effectiveness order in increasing the duration of drug action was SUV> or =MLV>LUV approximately FATMLV. The highest efficacy of SUVs was probably due to the more intimate contact with the epithelium due to their greatest surface area, which allowed the longest extension of drug therapeutic

  3. Synergistic penetration of ethosomes and lipophilic prodrug on the transdermal delivery of acyclovir.

    Science.gov (United States)

    Zhou, Yan; Wei, Yu-Hui; Zhang, Guo-Qiang; Wu, Xin-An

    2010-04-01

    The aim of this study was to investigate the lipophilic prodrug as a means of promoting acyclovir (ACV) that exhibited biphasic insolubility into the ethosomes for optimum skin delivery. Acyclovir Palmitate (ACV-C(16)) was synthesized as the lipophilic prodrug of ACV. The ethosomal system and the liposomal system bearing ACV or ACV-C(16) were prepared, respectively. The systems were characterized for shape, zeta potential value, particle size, and entrapment efficiency. Franz diffusion cells and confocal laser scanning microscopy were used for the percutaneous absorption studies. The results showed that the entrapment efficiency of ACV-C(16) ethosomes (87.75%) were much higher than that of ACV ethosomes (39.13%). The quantity of drug in the skin from ACV-C(16) ethosomes at the end of the 24 h transdermal experiment (622.89 microg/cm(2)) was 5.30 and 3.43 times higher than that from ACV-C(16) hydroalcoholic solution and ACV ethosomes, respectively. This study indicated that the binary combination of the lipophilic prodrug ACV-C(16) and the ethosomes synergistically enhanced ACV absorption into the skin.

  4. Enhanced transdermal deposition and characterization of quercetin-loaded ethosomes

    Energy Technology Data Exchange (ETDEWEB)

    Park, Soo Nam; Lee, Hye Jin; Kim, Hae Soo; Park, Min A; Gu, Hyun A [Seoul National University of Science and Technology, Seoul (Korea, Republic of)

    2013-03-15

    We sought to evaluate the transdermal permeation potential of quercetin-loaded ethosomes. Quercetinloaded ethosomes were prepared and characterized with regard to particle size, loading efficiency, stability, and in vitro skin permeation. The optimized formulation of ethosomes was confirmed using 2% egg phosphatidylcholine and hydrated 20% ethanol. After quercetin was applied using this formulation, the stability of the ethosomes was determined when loaded with up to 0.04% quercetin. We observed that loading efficiency was improved with increasing concentrations of quercetin. Ethosomes loaded with 0.04% quercetin showed both the greatest loading efficiency (63.9%±6.0%) and an optimal size range (132±32 nm). Ethosomes loaded with quercetin were superior in skin permeation ability (29.5±7.0 µg/cm{sup 2}) compared to either ethanolic solution or liposomes. Therefore, we concluded that quercetin-loaded ethosomes increased the skin delivery of quercetin. Our results suggest that quercetin-loaded ethosomes may enhance the effect of cosmetic materials.

  5. A study on ethosomes as mode for transdermal delivery of an antidiabetic drug.

    Science.gov (United States)

    Bodade, Siddhodhan S; Shaikh, Karimunnisa Sameer; Kamble, Meghana S; Chaudhari, Praveen D

    2013-01-01

    A transdermal delivery system is warranted for repaglinide (RPG) which possesses half-life of 1 h and oral bioavailability of 56%. Ethosomes are useful tools for transdermal drug delivery. To prepare and evaluate ethosomes as mode for transdermal delivery of RPG. Ethosomes loaded with RPG were prepared from dipalmitoyl phosphatidylcholine and ethanol by the cold method. They were characterized using Fourier transform infrared spectroscopy and differential scanning calorimetry. They were evaluated for vesicle size, entrapment efficiency and ex-vivo skin permeation. Ethosomal composition was optimized using the 3(2) factorial design. Gel containing optimzsed ethosomes was studied for antidiabetic activity in rats. RPG ethosomes possessing the size of 0.171-1.727 µm and entrapment efficiency of 75-92% were obtained. They demonstrated a significantly higher permeation (64-97% of the administered dose) across excised rat skin when compared to free drug and its hydro alcoholic solution. In-vivo, RPG ethosomal system caused sustained antidiabetic effect. The lipid and ethanol concentration affected the physicochemical attributes and performance of ethosomes. The flexible ethosomes permeated the stratum corneum and improvized the availability of RPG for antidiabetic action. They prolonged the antidiabetic effect of RPG over a significantly longer period of time in comparison with the equivalent oral dose. Ethosomal system can successfully deliver RPG transdermally; sustain its effect and thus reduce its dosing frequency. Ethosomes are useful for enhancing the efficacy of RPG in the treatment of diabetes.

  6. Ethosome formulation of contact allergens may enhance patch test reactions in patients

    DEFF Research Database (Denmark)

    Madsen, Jakob Torp; Vogel, Stefan; Karlberg, Ann-Therese

    2010-01-01

    carrier systems may increase the allergenicity potential. Objectives: To investigate the effect of ethosome formulation of isoeugenol and methyldibromo glutaronitrile on the elicitation response under patch test conditions and by repeated open applications. Patients/Materials/Methods: A total of 27......, a repeated open application test (ROAT) was performed in a subset of 16 patients, and lag time until a positive response was recorded. Results: Both contact allergens encapsulated in ethosomes showed significantly enhanced patch test reactions as compared with the allergen preparation in ethanol....../water without ethosomes. No significant difference in the median lag time was recorded between preparations in the ROAT. Conclusions: Encapsulating potential contact allergens in ethosomes may increase the challenge response as compared with the same concentrations in an ethanol/water base without ethosomes....

  7. Therapeutic and cosmeceutical potential of ethosomes: An overview

    Directory of Open Access Journals (Sweden)

    Poonam Verma

    2010-01-01

    Full Text Available The main disadvantage of transdermal drug delivery is the poor penetration of most compounds into the human skin. The main barrier of the skin is located within its uppermost layer, the stratum corneum (SC. Several approaches have been developed to weaken this skin barrier. One of the approaches for increasing the skin penetration of drugs and many cosmetic chemicals is the use of vesicular systems, such as, liposomes and ethosomes. Ethosomes are phospholipid-based elastic nanovesicles containing a high content of ethanol (20-45%. Ethanol is known as an efficient permeation enhancer and has been added in the vesicular systems to prepare elastic nanovesicles. It can interact with the polar head group region of the lipid molecules, resulting in the reduction of the melting point of the stratum corneum lipid, thereby increasing lipid fluidity and cell membrane permeability. The high flexibility of vesicular membranes from the added ethanol permits the elastic vesicles to squeeze themselves through the pores, which are much smaller than their diameters. Ethosomal systems are much more efficient in delivering substances to the skin in the terms of quantity and depth, than either conventional liposomes or hydroalcoholic solutions. The scope of this small review is to introduce the novel concept of ethosomes and to describe some approaches and mechanisms of stimulating topical and transdermal products with ethosomes.

  8. Therapeutic and cosmeceutical potential of ethosomes: An overview.

    Science.gov (United States)

    Verma, Poonam; Pathak, K

    2010-07-01

    The main disadvantage of transdermal drug delivery is the poor penetration of most compounds into the human skin. The main barrier of the skin is located within its uppermost layer, the stratum corneum (SC). Several approaches have been developed to weaken this skin barrier. One of the approaches for increasing the skin penetration of drugs and many cosmetic chemicals is the use of vesicular systems, such as, liposomes and ethosomes. Ethosomes are phospholipid-based elastic nanovesicles containing a high content of ethanol (20-45%). Ethanol is known as an efficient permeation enhancer and has been added in the vesicular systems to prepare elastic nanovesicles. It can interact with the polar head group region of the lipid molecules, resulting in the reduction of the melting point of the stratum corneum lipid, thereby increasing lipid fluidity and cell membrane permeability. The high flexibility of vesicular membranes from the added ethanol permits the elastic vesicles to squeeze themselves through the pores, which are much smaller than their diameters. Ethosomal systems are much more efficient in delivering substances to the skin in the terms of quantity and depth, than either conventional liposomes or hydroalcoholic solutions. The scope of this small review is to introduce the novel concept of ethosomes and to describe some approaches and mechanisms of stimulating topical and transdermal products with ethosomes.

  9. Ethosome formulation of contact allergens may enhance patch test reactions in patients.

    Science.gov (United States)

    Madsen, Jakob Torp; Vogel, Stefan; Karlberg, Ann-Therese; Simonsson, Carl; Johansen, Jeanne Duus; Andersen, Klaus E

    2010-10-01

    Ethosomes and liposomes are ultra-small vesicles capable of encapsulating drugs and cosmetic ingredients for topical use, thereby potentially increasing bioavailability and clinical efficacy. So far, few reports have suggested that formulation of cosmetic ingredients in vesicular carrier systems may increase the allergenicity potential. To investigate the effect of ethosome formulation of isoeugenol and methyldibromo glutaronitrile on the elicitation response under patch test conditions and by repeated open applications. A total of 27 volunteer patients with a previous positive patch test reaction to either isoeugenol or methyldibromo glutaronitrile were included in the study. In all patients, a serial dilution patch test was performed with the allergen in question formulated in ethosomes and in an ethanol/water solution. In addition, a repeated open application test (ROAT) was performed in a subset of 16 patients, and lag time until a positive response was recorded. Both contact allergens encapsulated in ethosomes showed significantly enhanced patch test reactions as compared with the allergen preparation in ethanol/water without ethosomes. No significant difference in the median lag time was recorded between preparations in the ROAT. Encapsulating potential contact allergens in ethosomes may increase the challenge response as compared with the same concentrations in an ethanol/water base without ethosomes. © 2010 John Wiley & Sons A/S.

  10. Transdermal delivery of vancomycin hydrochloride using combination of nano-ethosomes and iontophoresis: in vitro and in vivo study.

    Science.gov (United States)

    Mohammed, Magdy I; Makky, Amna M A; Teaima, Mahmoud H M; Abdellatif, Menna M; Hamzawy, Mohamed A; Khalil, Mahmoud A F

    2016-06-01

    This study aimed to evaluate transdermal delivery of vancomycin hydrochloride using the combination of ethosomes as an encapsulating vesicle and iontophoresis. Ethosomes were prepared and evaluated in terms of electrochemical stability. Cathodal iontophoresis of negatively charged ethosomes and anodal iontophoresis of free drug solution and positively charged vesicles were conducted. The effect of current mode, density, concentration of drug and ionic strength was studied. In vivo study was performed by inducing mediastinitis in Sprague-Dawley rats using methicillin-resistant Staphylococcus aureus as infected pathogen, the mean bacterial count was compared between groups of rats, one of the treated groups received drug intramuscularly while the other group received vancomycin using iontophoretic delivery of optimized ethosomal formula. Ethosomes showed efficient electrochemical stability, cathodal iontophoresis of negatively charged vesicle (F2) showed maximum transdermal flux (550 µg/cm(2)/h) compared to free drug solution and other ethosomal formulae, transdermal flux was reduced by altering current mode from continuous to ON/OFF mode, reducing current density and by using normal saline as drug solvent; on the other hand, flux was potentiated by increasing drug concentration from 25 to 75 mg/ml. In vivo study revealed that there was a significant difference in terms of bacterial count between untreated and treated groups, while there was no statistically significant difference between the I.M. vancomycin treatment and treatment conducted by iontophoretic delivery of vancomycin encapsulated in ethosomal formula. Combination between ethosomes and iontophoresis had succeeded in delivering vancomycin transdermally.

  11. Ethosomes for enhanced skin delivery of griseofulvin.

    Science.gov (United States)

    Marto, Joana; Vitor, Catarina; Guerreiro, Ana; Severino, Cristiana; Eleutério, Carla; Ascenso, Andreia; Simões, Sandra

    2016-10-01

    Griseofulvin (GRF) is an important antifungal drug with low bioavailability and, for this reason, a topical formulation with a targeted action and minimal systemic effects, appears to be a preferable solution. GRF poor solubility has limited the development of topical formulations and their release to the market. The aim of this work was to prepare a new GRF formulation for topical application using lipid-based nanosystems; to study its permeation and penetration, cell viability and to evaluate its therapeutic action. Ethosomal systems composed of soy bean phosphatidylcholine, ethanol and water were prepared for incorporating GRF. After the characterization of the vesicles in terms of size, charge and penetrability, permeation through newborn pig using Franz diffusion cells was conducted. Cell viability at different concentrations of the chosen formulation was determined. At last, skin adapted agar diffusion test was performed to assess the therapeutic efficacy of the formulation. GRF vesicles had mean size of 130nm. Permeation and penetration assays revealed that GRF-loaded ethosomes have an adequate profile to be used in a topical formulation since drug retention in the stratum corneum was achieved. Cell viability tests proved this formulation presented no cytotoxicity to HaCaT cells for concentrations below 50μg/mL. The skin diffusion test evidenced the potential of developed formulation to target skin dermatophytes. The results obtained in this study contribute to a new perspective in topical treatment of fungal infections. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Dermatopharmacokinetic and pharmacodynamic evaluation of ethosomes of griseofulvin designed for dermal delivery

    Energy Technology Data Exchange (ETDEWEB)

    Aggarwal, Nidhi; Goindi, Shishu, E-mail: shishugoindi@yahoo.co.in [Panjab University, University Institute of Pharmaceutical Sciences (India)

    2013-10-15

    The present study is aimed at evaluation of the dermal delivery potential of griseofulvin-loaded ethosomes. Griseofulvin-loaded ethosomes were prepared using 'Cold technique' (Indian Patent Application 208/DEL/2009). The optimized formulation was characterized for vesicular shape and size, drug entrapment efficiency, drug content, pH, stability, and spreadability. Ex vivo skin permeation, dermatopharmacokinetics, and skin sensitivity studies were carried out using male Laca mice. In vivo antifungal activity was assessed against Microsporum canis using guinea pig model for dermatophytosis. The optimized formulation E7 possessing 2 % phospholipid (PL) and 30 % ethanol exhibited the highest drug entrapment (72.94 {+-} 0.80 %) and optimum vesicle size (148.5 {+-} 0.48 nm). E7 illustrated remarkably higher drug permeation and skin retention when compared with liposomes. Pharmacodynamic studies in guinea pigs induced with M. canis revealed that the dermal fungal infection was completely cured in 8 days upon twice daily topical application of griseofulvin-loaded ethosomes whereas liposomes led to complete cure in 14 days. The formulation was observed to be non-sensitizing, histopathologically safe, and stable at 5 {+-} 3, 25 {+-} 2, and 40 {+-} 2 Degree-Sign C for a period of 1 year. Results indicated that dermal delivery of griseofulvin employing ethosomes could be a commendable alternative to reduce the bio-burden associated with conventional oral formulations.

  13. Dermatopharmacokinetic and pharmacodynamic evaluation of ethosomes of griseofulvin designed for dermal delivery

    Science.gov (United States)

    Aggarwal, Nidhi; Goindi, Shishu

    2013-10-01

    The present study is aimed at evaluation of the dermal delivery potential of griseofulvin-loaded ethosomes. Griseofulvin-loaded ethosomes were prepared using "Cold technique" (Indian Patent Application 208/DEL/2009). The optimized formulation was characterized for vesicular shape and size, drug entrapment efficiency, drug content, pH, stability, and spreadability. Ex vivo skin permeation, dermatopharmacokinetics, and skin sensitivity studies were carried out using male Laca mice. In vivo antifungal activity was assessed against Microsporum canis using guinea pig model for dermatophytosis. The optimized formulation E7 possessing 2 % phospholipid (PL) and 30 % ethanol exhibited the highest drug entrapment (72.94 ± 0.80 %) and optimum vesicle size (148.5 ± 0.48 nm). E7 illustrated remarkably higher drug permeation and skin retention when compared with liposomes. Pharmacodynamic studies in guinea pigs induced with M. canis revealed that the dermal fungal infection was completely cured in 8 days upon twice daily topical application of griseofulvin-loaded ethosomes whereas liposomes led to complete cure in 14 days. The formulation was observed to be non-sensitizing, histopathologically safe, and stable at 5 ± 3, 25 ± 2, and 40 ± 2 °C for a period of 1 year. Results indicated that dermal delivery of griseofulvin employing ethosomes could be a commendable alternative to reduce the bio-burden associated with conventional oral formulations.

  14. Quality by design approach for formulation, evaluation and statistical optimization of diclofenac-loaded ethosomes via transdermal route.

    Science.gov (United States)

    Jain, Shashank; Patel, Niketkumar; Madan, Parshotam; Lin, Senshang

    2015-06-01

    The objective of this study was to fabricate and understand ethosomal formulations of diclofenac (DF) for enhanced anti-inflammatory activity using quality by design approach. DF-loaded ethosomal formulations were prepared using 4 × 5 full-factorial design with phosphatidylcholine:cholesterol (PC:CH) ratios ranging between 50:50 and 90:10, and ethanol concentration ranging between 0% and 30% as formulation variables. These formulations were characterized in terms of physicochemical properties and skin permeation kinetics. The interaction of formulation variables had a significant effect on both physicochemical properties and permeation kinetics. The results of multivariate regression analysis illustrated that vesicle size and elasticity of ethosomes were the dominating physicochemical properties affecting skin permeation, and could be suitably controlled by manipulation of formulation variables to optimize the formulation and enhance the skin permeation of DF-loaded ethosomes. The optimized formulation had ethanol concentration of 22.9% and PC:CH ratio of 88.4:11.6, with vesicle size of 144 ± 5 nm, zeta potential of -23.0 ± 3.76 mV, elasticity of 2.48 ± 0.75 and entrapment efficiency of 71 ± 4%. Permeation flux for the optimized formulation was 12.9 ± 1.0 µg/h cm(2), which was significantly higher than the drug-loaded conventional liposome, ethanolic or aqueous solution. The in vivo study indicated that optimized ethosomal hydrogel exhibited enhanced anti-inflammatory activity compared with liposomal and plain drug hydrogel formulations.

  15. Therapeutic and cosmeceutical potential of ethosomes: An overview

    OpenAIRE

    Verma, Poonam; Pathak, K.

    2010-01-01

    The main disadvantage of transdermal drug delivery is the poor penetration of most compounds into the human skin. The main barrier of the skin is located within its uppermost layer, the stratum corneum (SC). Several approaches have been developed to weaken this skin barrier. One of the approaches for increasing the skin penetration of drugs and many cosmetic chemicals is the use of vesicular systems, such as, liposomes and ethosomes. Ethosomes are phospholipid-based elastic nanovesicles conta...

  16. Radiation preparation and application of the linear thermosensitive binary copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Yi Min; Li Jun; Zhang Jianbo; Jiang Guilin; Qin Jianhua; Ha Hongfei

    1998-06-01

    Linear poly(NIPAAm-co-X), with X being AAc or 4-VP, was synthesized by means of {gamma} radiation induced polymerization in tetrahydrofuran (THF). The binary copolymers obtained are possessed of water-soluble, temperature sensitivity. It was also found that raising pH leads to a higher LCST when X is AAc. Prepared copolymers were used to concentrate metal ions, such as UO{sub 2}{sup 2+} RE{sup 3+} and Cr(VI) in dilute aqueous solution, which showed obvious concentration effect. The conditions of ion concentration were given and the mechanism was discussed preliminary.

  17. Ethosome formulations of known contact allergens can increase their sensitizing capacity.

    Science.gov (United States)

    Madsen, Jacob Torp; Vogel, Stefan; Karlberg, Ann-Therese; Simonsson, Carl; Johansen, Jeanne D; Andersen, Klaus E

    2010-07-01

    Vesicular systems, such as liposomes and ethosomes, are used in cosmetic and pharmaceutical products to encapsulate ingredients, to protect ingredients from degradation, to increase bioavailability, and to improve cosmetic performance. Some reports have suggested that formulation of cosmetic ingredients in vesicular carrier systems may increase their contact allergy elicitation potential in humans. However, no sensitization studies have been published. We formulated two model contact allergens (isoeugenol and dinitrochlorobenzene) in ethosomes and investigated the sensitization response using a modified local lymph node assay (LLNA). The results were compared with those for the same allergens in similar concentrations and vehicles without ethosomes. Both allergens encapsulated in 200-300 nm ethosomes showed increased sensitizing potency in the murine assay compared with the allergens in solution without ethosomes. Empty ethosomes were non-sensitizing according to LLNA. The clinical implications are so far uncertain, but increased allergenicity from ethosome-encapsulated topical product ingredients cannot be excluded.

  18. Development, characterization, and skin delivery studies of related ultradeformable vesicles: transfersomes, ethosomes, and transethosomes

    Directory of Open Access Journals (Sweden)

    Ascenso A

    2015-09-01

    Full Text Available Andreia Ascenso,1 Sara Raposo,1 Cátia Batista,2 Pedro Cardoso,2 Tiago Mendes,2 Fabíola Garcia Praça,3 Maria Vitória Lopes Badra Bentley,3 Sandra Simões1 1Instituto de Investigação do Medicamento (iMed.ULisboa, 2Faculdade de Farmácia, Universidade de Lisboa, Lisboa, Portugal; 3Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Monte Alegre, Ribeirão Preto, São Paulo, Brazil Abstract: Ultradeformable vesicles (UDV have recently become a promising tool for the development of improved and innovative dermal and transdermal therapies. The aim of this work was to study three related UDV: transfersomes, ethosomes, and transethosomes for the incorporation of actives of distinct polarities, namely, vitamin E and caffeine, and to evaluate the effect of the carrier on skin permeation and penetration. These actives were incorporated in UDV formulations further characterized for vesicles imaging by transmission electron microscopy; mean vesicle size and polydispersity index by photon correlation spectroscopy; zeta potential by laser-Doppler anemometry; deformability by pressure-driven transport; and incorporation efficiency (IE after actives quantification by high-performance liquid chromatography. Topical delivery studies were performed in order to compare UDV formulations regarding the release, skin permeation, and penetration profiles. All UDV formulations showed size values within the expected range, except transethosomes prepared by “transfersomal method”, for which size was smaller than 100 nm in contrast to that obtained for vesicles prepared by “ethosomal method”. Zeta potential was negative and higher for formulations containing sodium cholate. The IE was much higher for vitamin E- than caffeine-loaded UDV as expected. For flux measurements, the following order was obtained: transethosomes (TE > ethosomes (E ≥ transfersomes (T. This result was consistent with the release and skin penetration

  19. Evaluation of Anti-Cancer Properties of Pegylated Ethosomal ...

    African Journals Online (AJOL)

    Two properties facilitate nanoparticle penetration of skin. First, the ethanol in ethosomes increases lipidic membrane fluidity of skin cells. Second, deformability also enhances skin penetration by nanoparticles [8]. Malignant melanoma is the most aggressive form of skin cancer. The outbreak of the disease is faster than any ...

  20. Ethosomes and liposomes as topical vehicles for azelaic acid: a preformulation study.

    Science.gov (United States)

    Esposito, Elisabetta; Menegatti, Enea; Cortesi, Rita

    2004-01-01

    The basic properties and the in vitro release rate kinetics of azelaic acid (AA), alternatively vehiculated in different phospholipid-based vesicles such as ethosomes or liposomes, were investigated. Ethosomes were produced by a simple method based on addition of an aqueous phase to an ethanol solution (comprised between 20\\% and 45%, v/v) of soy phosphatidyl choline (5%, w/w) and AA (0.2%, w/w) under mechanical stirring. Liposomes were obtained by the same composition in the absence of ethanol with the reverse-phase evaporation method. Vesicle size was measured by photon correlation spectroscopy (PCS), evidencing smaller mean diameters and narrower dimensional distributions in the case of ethosomes with respect to liposomes. In order to obtain homogeneously sized vesicles, both ethosomal and liposomal dispersions were extruded through polycarbonate membranes with pores of calibrated diameter (400 nm and 200 nm). Vesicle morphology was characterized by freeze-fracture scanning electron microscopy (SEM) showing the presence of unilamellar vesicles both in liposome- and in ethosome-based dispersions. Free energy measurements of the vesicle bilayers were conducted by differential scanning calorimetry (DSC). AA diffusion from ethosomal or liposomal dispersions and from ethosomes and liposomes incorporated in a viscous gel was investigated by a Franz cell assembled with synthetic membranes. The release rate was more rapid from ethosomal systems than from liposomal systems. In particular, ethosomes produced by the highest ethanol concentration released AA more rapidly, and the same trend was found using viscous forms.

  1. Ethosome formulations of known contact allergens can increase their sensitizing capacity

    DEFF Research Database (Denmark)

    Madsen, Jakob Torp; Vogel, Stefan; Karlberg, Ann-Therese

    2010-01-01

    Vesicular systems, such as liposomes and ethosomes, are used in cosmetic and pharmaceutical products to encapsulate ingredients, to protect ingredients from degradation, to increase bioavailability, and to improve cosmetic performance. Some reports have suggested that formulation of cosmetic...

  2. Comparative study of liposomes, transfersomes, ethosomes and cubosomes for transcutaneous immunisation

    DEFF Research Database (Denmark)

    Rattanapak, Teerawan; Young, Katie; Rades, Thomas

    2012-01-01

    Objectives Lipid colloidal vaccines, including liposomes, transfersomes, ethosomes and cubosomes, were formulated, characterised and investigated for their ability to enhance penetration of a peptide vaccine through stillborn piglet skin in vitro. Methods Liposomes and transfersomes were formulat...

  3. Ethosome formulation of contact allergens may enhance patch test reactions in patients

    DEFF Research Database (Denmark)

    Madsen, Jakob Torp; Vogel, Stefan; Karlberg, Ann-Therese

    2010-01-01

    Ethosomes and liposomes are ultra-small vesicles capable of encapsulating drugs and cosmetic ingredients for topical use, thereby potentially increasing bioavailability and clinical efficacy. So far, few reports have suggested that formulation of cosmetic ingredients in vesicular carrier systems ...

  4. Percutaneous penetration characteristics and release kinetics of contact allergens encapsulated in ethosomes

    DEFF Research Database (Denmark)

    Madsen, Jakob Torp; Vogel, Stefan; Johansen, Jeanne Duus

    2011-01-01

    Formulation of the contact allergens dinitrochlorobenzene and isoeugenol in ethanolic liposomes (ethosomes) increases their sensitizing properties in the local lymph node assay compared with an ethanol-water formulation of the allergens. Likewise, isoeugenol and methyldibromo-glutaronitrile formu...

  5. Percutaneous penetration characteristics and release kinetics of contact allergens encapsulated in ethosomes

    DEFF Research Database (Denmark)

    Madsen, Jakob Torp; Vogel, Stefan; Johansen, Jeanne Duus

    2011-01-01

    Formulation of the contact allergens dinitrochlorobenzene and isoeugenol in ethanolic liposomes (ethosomes) increases their sensitizing properties in the local lymph node assay compared with an ethanol-water formulation of the allergens. Likewise, isoeugenol and methyldibromo-glutaronitrile formu......-glutaronitrile formulated in ethosomes enhanced the patch test reactions in sensitized human volunteers. The relationship between the percutaneous penetration/absorption and sensitization/elicitation phases of contact allergy is not well elucidated....

  6. Tunable porous nanoallotropes prepared by post-assembly etching of binary nanoparticle superlattices

    Science.gov (United States)

    Udayabhaskararao, Thumu; Altantzis, Thomas; Houben, Lothar; Coronado-Puchau, Marc; Langer, Judith; Popovitz-Biro, Ronit; Liz-Marzán, Luis M.; Vuković, Lela; Král, Petr; Bals, Sara; Klajn, Rafal

    2017-10-01

    Self-assembly of inorganic nanoparticles has been used to prepare hundreds of different colloidal crystals, but almost invariably with the restriction that the particles must be densely packed. Here, we show that non–close-packed nanoparticle arrays can be fabricated through the selective removal of one of two components comprising binary nanoparticle superlattices. First, a variety of binary nanoparticle superlattices were prepared at the liquid-air interface, including several arrangements that were previously unknown. Molecular dynamics simulations revealed the particular role of the liquid in templating the formation of superlattices not achievable through self-assembly in bulk solution. Second, upon stabilization, all of these binary superlattices could be transformed into distinct “nanoallotropes”—nanoporous materials having the same chemical composition but differing in their nanoscale architectures.

  7. Solid state amorphisation in binary systems prepared by mechanical alloying

    International Nuclear Information System (INIS)

    Gonzalez, G.; Sagarzazu, A.; Bonyuet, D.; D'Angelo, L.; Villalba, R.

    2009-01-01

    In the present work a detailed study of amorphisation in different systems prepared by mechanical alloying under the same experimental conditions was carried out, milling up to 50 and 100 h in some cases. The systems studied were: AlTi, AlNi, AlFe, FeNi, FeCo, NiMo, NiW, NiCo, MoW, CoMo. These systems were chosen to study the effect of Al-transition metal, transition metal-transition metal and also systems with large and small negative heat of mixing, different and similar crystal structures, atomic sizes and diffusion coefficients. Calculations based on the Miedema model for alloy formation and amorphisation on all the alloys studied were performed. The experimental results from X-ray diffraction and transmission electron microscopy showed that the systems based on Fe (FeNi, FeCo and FeAl) did not amorphised, even after milling for 100 h, and formed a stable solid solution with a nanometric grain size of 7 nm. The systems NiMo, NiW, MoW and CoMo (systems with small negative heat of mixing), showed amorphisation after 50 h of milling. NiAl and TiAl form an intermediate amorphous phase after around 20 h of milling and with further milling they recrystallize into a fcc solid solution. Agreement between the theoretical calculations based on the Miedema model and the experimental results was found in most of the systems.

  8. Enhanced in Vivo Delivery of 5-Fluorouracil by Ethosomal Gels in Rabbit Ear Hypertrophic Scar Model

    Directory of Open Access Journals (Sweden)

    Yan Wo

    2014-12-01

    Full Text Available Applying Ethosomal Gels (EGs in transdermal drug delivery systems has evoked considerable interest because of their good water-solubility and biocompatibility. However, there has not been an explicit description of applying EGs as a vehicle for hypertrophic scars treatment. Here, a novel transdermal EGs loaded with 5-fluorouracil (5-FU EGs was successfully prepared and characterized. The stability assay in vitro revealed that 5-FU EGs stored for a period of 30 days at 4 ± 1 °C had a better size stability than that at 25 ± 1 °C. Furthermore, using confocal laser scanning microscopy, EGs labeled with Rhodamine 6 G penetrated into the deep dermis of the hypertrophic scar within 24 h in the rabbit ear hypertrophic model suggested that the EGs were an optional delivery carrier through scar tissues. In addition, the value of the Scar Elevation Index (SEI of 5-FU EGs group in the rabbit ear scar model was lower than that of 5-FU Phosphate Buffered Saline gel and Control groups. To conclude, these results suggest that EGs delivery system loaded 5-fluorouracil is a perfect candidate drug for hypertrophic scars therapy in future.

  9. Biocompatible 5-Aminolevulinic Acid/Au Nanoparticle-Loaded Ethosomal Vesicles for In Vitro Transdermal Synergistic Photodynamic/Photothermal Therapy of Hypertrophic Scars

    Science.gov (United States)

    Zhang, Zheng; Chen, Yunsheng; Ding, Jiayue; Zhang, Chunlei; Zhang, Amin; He, Dannong; Zhang, Yixin

    2017-12-01

    Biocompatible 5-aminolevulinic acid/Au nanoparticle-loaded ethosomal vesicle (A/A-ES) is prepared via ultrasonication for synergistic transdermal photodynamic/photothermal therapy (PDT/PTT) of hypertrophic scar (HS). Utilizing ultrasonication, Au nanoparticles (AuNPs) are synthesized and simultaneously loaded in ethosomal vesicles (ES) without any toxic agents, and 5-aminolevulinic acid (ALA) is also loaded in ES with 20% of the entrapment efficiency (EE). The prepared A/A-ES displays strong absorbance in 600-650 nm due to the plasmonic coupling effect between neighboring AuNPs in the same A/A-ES, which can simultaneously stimulate A/A-ES to produce heat and enhance quantum yields of reactive oxygen species (ROS) by using 632 nm laser. In vitro transdermal penetrability study demonstrates that A/A-ES acts as a highly efficient drug carrier to enhance both ALA and AuNPs penetration into HS tissue . Taking human hypertrophic scar fibroblasts (HSF) as therapeutic targets, synergistic PDT/PTT of HS indicates that A/A-ES could enhance quantum yields of ROS by photothermal effect and localized surface plasmon resonance (LSPR) of AuNPs, resulting in a high level of apoptosis or necrosis. In a word, the prepared A/A-ES shows a better synergistic PDT/PTT efficiency for HSF than the individual PDT and PTT, encouraging perspective for treatment of HS.

  10. Membranes prepared by radiation grafting of binary monomers for adsorption of heavy metals from industrial wastes

    Science.gov (United States)

    Hegazy, El-Sayed A.; Kamal, H.; Maziad, N.; Dessouki, A. M.

    1999-05-01

    Preparation of synthetic membranes using simultaneous radiation grafting of acrylic acid (AAc) and styrene (Sty) as individually and in binary monomer mixture onto low density polyethylene (LDPE) has been carried out. The effect of preparation conditions such as irradiation dose, monomer concentration, comonomer composition, and solvent on the grafting yield was investigated. Characterization and some properties of the prepared membranes using different analytical techniques are studied, accordingly the possibility of its practical use in industrial waste treatment is determined. The swelling behavior, electrical conductivity, thermal stability, and mechanical properties of the membranes were investigated as a function of the grafting degree. The prepared cation-exchange membranes possessed good electrical and mechanical properties, high thermal stability and possess good characteristics for separation processes. These membranes have also good affinity toward the adsorption or chelation with Fe 3+ and Pb 2+ ions either in mixture containing other metals or if exists alone in the waste solution.

  11. Study on preparation and thermal property of binary fatty acid and the binary fatty acids/diatomite composite phase change materials

    International Nuclear Information System (INIS)

    Li, Min; Kao, Hongtao; Wu, Zhishen; Tan, Jinmiao

    2011-01-01

    This study prepared a series of binary phase change materials by mixing decanoic acid, dodecanoic acid, hexadecanoic acid and octadecanoic acid each other. The phase-transition temperature of binary fatty acid and its corresponding mixing proportion are calculated with phase diagram thermodynamic method. The results are verified by the experimental result of the heat absorption curve and the Differential Scanning Calorimetry (DSC) analysis curve. The results show that the calculation method of phase diagram thermodynamic calculation can be taken as a basis for mixing proportion of binary fatty acid phase change materials. In addition, the decanoic-dodecanoic acid/diatomite composite phase change material (PCM) are prepared and its microstructure, thermal property and thermal reliability are characterized. The result shows that the decanoic-dodecanoic acid is uniformly adsorbed into diatomite and the form-stable PCM are formed. The phase-transition temperature and the latent heat of the decanoic-dodecanoic acid/diatomite composite PCMs is 16.74 o C and 66.8114 J/g, respectively.

  12. Ethosomes-based topical delivery system of antihistaminic drug for treatment of skin allergies.

    Science.gov (United States)

    Goindi, Shishu; Dhatt, Bhavnita; Kaur, Amanpreet

    2014-01-01

    Cetirizine is indicated for the treatment of allergic conditions such as insect bites and stings, atopic and contact dermatitis, eczema, urticaria. This investigation deals with development of a novel ethosome-based topical formulation of cetirizine dihydrochloride for effective delivery. The optimised formulation consisting of drug, phospholipon 90 G™ and ethanol was characterised for drug content, entrapment efficiency, pH, vesicular size, spreadability and rheological behaviour. The ex vivo permeation studies through mice skin showed highest permeation flux (16.300 ± 0.300 µg/h/cm(2)) and skin retention (20.686 ± 0.517 µg/cm(2)) for cetirizine-loaded ethosomal vesicles as compared to conventional formulations. The in vivo pharmacodynamic evaluation of optimised formulation was assessed against oxazolone-induced atopic dermatitis (AD) in mice. The parameters evaluated were reduction in scratching score, erythema score, skin hyperplasia and dermal eosinophil count. Our results suggest that ethosomes are effective carriers for dermal delivery of antihistaminic drug, cetirizine, for the treatment of AD.

  13. Preparation, characterization and thermal properties of binary nitrate salts/expanded graphite as composite phase change material

    International Nuclear Information System (INIS)

    Xiao, Junbing; Huang, Jin; Zhu, Panpan; Wang, Changhong; Li, Xinxi

    2014-01-01

    Highlights: • The expanded graphite enhanced thermal conductivity coefficient greatly. • The aqueous solution method adopting ultrasonic was utilized to disperse EG. • The combination of composite was physical without chemical reaction. • The reduction on total latent heat was slight after the adding EG. - Abstract: The binary nitrate salts/expanded graphite (EG) composite phase change material (PCM) were prepared via adding different mass rate of EG to binary nitrate salts consisting of NaNO 3 and KNO 3 (6:4) by aqueous solution method adopting ultrasonic. The morphology and chemical composition of EG and the composite PCM were characterized and investigated by X-ray diffraction (XRD), scan electron microscope (SEM), energy dispersive spectrometer (EDS), transmission electron microscope (TEM), respectively. Laser thermal conductivity instrument and differential scanning calorimeter (DSC) were employed to measure thermo physical properties. Drawing the conclusion from investigation, that EG had enhanced thermal conductivity coefficient which largely increased to 4.884 W/(m K) and reduced total latent heat by mostly 11.0%. The morphology and phase structure results indicated that EG were well dispersed into and physically combined with molten salts. In general, the prepared composite PCM could be a suitable phase change material for thermal energy storage

  14. Encapsulating contact allergens in liposomes, ethosomes, and polycaprolactone may affect their sensitizing properties

    DEFF Research Database (Denmark)

    Madsen, Jakob Torp; Vogel, Stefan; Johansen, Jeanne Duus

    2011-01-01

    Attempts to improve formulation of topical products are a continuing process and the development of micro- and nanovesicular systems as well as polymeric microparticles has led to marketing of topical drugs and cosmetics using these technologies. Encapsulation of some well-known contact allergens...... in ethanolic liposomes have been reported to enhance allergenicity compared with the allergens in similar vehicles without liposomes. The present report includes data on more sensitization studies using the mouse local lymph node assay with three contact allergens encapsulated in different dermal drug......-delivery systems: liposomes, ethosomes, and polycaprolactone particles. The results show that the drug-delivery systems are not sensitizers in themselves. Encapsulating the hydrophilic contact allergen potassium dichromate in all three drug-delivery systems did not affect the sensitizing capacity of potassium...

  15. Research on the Preparation and Performance of Binary Modified Maltodextrin Water-Reducing Agent

    Directory of Open Access Journals (Sweden)

    Jingzhi Wu

    2016-01-01

    Full Text Available Using maltodextrin (MD of different dextrose equivalent (DE values, 1,3-propanesultone, and maleic anhydride as raw materials, a novel binary modified maltodextrin (BMMD was synthesized and further applied as a water-reducing agent. Its structure was characterized by Fourier transform infrared (FT-IR and UV. The rheological behavior of the sample solution and strengths for concrete were also determined and the adsorption was tested by TOC. The influence of the process parameters to degree of substitution (DS and the dosage on the fluidity of cement paste were investigated. The results show that the optimal conditions of sulfonation were the MD of DE 15, m (sulfonated agent/m (MD of 1.4, the catalyst amount of 1% by mass MD, and the reaction time of 12 h; the optimal conditions of esterification were m (esterified agent/m (SMD of 0.6, the reaction temperature of 90°C, and the reaction time of 4 h. The optimal dosages of sulfonated maltodextrin (SMD and BMMD were 0.475% and 0.45%, respectively. In this dosage, the main dispersion capacity of BMMD attributes to two kinds of anchoring groups (SO3-  &  COO- and the appropriate molecular weight of MD.

  16. Rapid microwave-assisted preparation of binary and ternary transition metal sulfide compounds

    Energy Technology Data Exchange (ETDEWEB)

    Butala, Megan M.; Perez, Minue A.; Arnon, Shiri; Göbel, Claudia; Preefer, Molleigh B.; Seshadri, Ram

    2017-12-01

    Transition metal chalcogenides are of interest for energy applications, including energy generation in photoelectrochemical cells and as electrodes for next-generation electrochemical energy storage. Synthetic routes for such chalcogenides typically involve extended heating at elevated temperatures for multiple weeks. We demonstrate here the feasibility of rapidly preparing select sulfide compounds in a matter of minutes, rather than weeks, using microwave-assisted heating in domestic microwaves. We report the preparations of phase pure FeS2, CoS2, and solid solutions thereof from the elements with only 40 min of heating. Conventional furnace and rapid microwave preparations of CuTi2S4 both result in a majority of the targeted phase, even with the significantly shorter heating time of 40 min for microwave methods relative to 12 days using a conventional furnace. The preparations we describe for these compounds can be extended to related structures and chemistries and thus enable rapid screening of the properties and performance of various compositions of interest for electronic, optical, and electrochemical applications.

  17. Preparation of poly (vinyl alcohol) membranes grafted with n-vinyl pyridine/ acrylic acid binary monomers

    International Nuclear Information System (INIS)

    Ajji, A.; Ali, A.

    2014-03-01

    Poly(vinyl alcohol) films were grafted with two monomers using gamma radiation, acrylic acid and N-vinyl pyridine. The influence of different parameters on the grafting yield was investigated as: the comonomer concentration and composition, and irradiation dose. The suitable conditions of the process had been determined to prepare PVA membranes have both properties of the two monomers, acrylic acid and vinyl pyridine as comonomer concentration and composition, and irradiation dose. Some properties of the membranes had been investigated as maximum swelling and grafting. Also the ability of the grafted films to adsorb some heavy metals and dyes was elaborated and discussed.(author)

  18. IrO2-SiO2 binary oxide films: Preparation, physiochemical characterization and their electrochemical properties

    International Nuclear Information System (INIS)

    Wang Xiaomei; Hu Jiming; Zhang Jianqing

    2010-01-01

    Mixed IrO 2 -SiO 2 oxide films were prepared on titanium substrate by the thermo-decomposition of hexachloroiridate (H 2 IrCl 6 ) and tetraethoxysilane (TEOS) mixed precursors in organic solvents. The solution chemistry and thermal decomposition kinetics of the mixed precursors were investigated by ultra violet/visible (UV/vis) spectroscopy and thermogravimetry (TGA) and differential thermal analysis (DTA), respectively. The physiochemical characterization of the resulting materials was conducted by X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical measurements. It is shown from the UV/vis spectra that the electronic absorption intensity of IrCl 6 2- complexes in the precursors decreases in the presence of TEOS, indicating the interaction between these two components. Thermal analysis shows the decomposition reaction of H 2 IrCl 6 is inhibited by TEOS in the low temperature range, but the further oxidation reaction at high temperatures of formed intermediates is independent of the presence of silane component. Physical measurements show a restriction effect of silica on the crystallization and crystal growth processes of IrO 2 , leading to the formation of finer oxide particles and the porous morphology of the binary oxide films. The porous composite films exhibit high apparent electrocatalytic activity toward the oxygen evolution reaction. In addition, the long-term stability of Ti-supported IrO 2 electrodes is found to apparently improve with appropriate amount of SiO 2 incorporation, as tested under galvanostatic electrolysis.

  19. Preparation of thermosensitive membranes by radiation grafting of acrylic acid/N-isopropyl acrylamide binary mixture on PET fabric

    International Nuclear Information System (INIS)

    Gupta, Bhuvanesh; Mishra, Swaiti; Saxena, Shalini

    2008-01-01

    Thermosensitive membranes were prepared by radiation-induced graft copolymerization of monomers on PET fabrics. A binary mixture of N-isopropyl acrylamide (NIPAAm) and acrylic acid (AA) was grafted on polyester fabric as a base material to introduce thermosensitive poly(N-isopropyl acrylamide) pendant chains having LCST slightly higher than 37 deg. C in the membrane. The influence of ferrous sulfate, radiation dose and monomer composition on the degree of grafting was studied. The structure of the grafted fabric was characterized by thermogravimetric analysis, differential scanning calorimetry and scanning electron microscopy. The thermosensitive nature of the fabric was monitored by swelling at different temperatures. The graft copolymerization of AA with NIPAAm enhanced the LCST of the resultant membrane to ∼37 deg. C. The moisture vapor transmission rate (MVTR) and air permeability of the fabric decreased slightly, may be due to the slight blocking of the fabric pores. The immobilization of tetracycline hydrochloride as the model drug and its release characteristics at different temperatures were monitored

  20. Encapsulating contact allergens in liposomes, ethosomes, and polycaprolactone may affect their sensitizing properties.

    Science.gov (United States)

    Madsen, Jakob Torp; Vogel, Stefan; Johansen, Jeanne Duus; Andersen, Klaus Ejner

    2011-06-01

    Attempts to improve formulation of topical products are a continuing process and the development of micro- and nanovesicular systems as well as polymeric microparticles has led to marketing of topical drugs and cosmetics using these technologies. Encapsulation of some well-known contact allergens in ethanolic liposomes have been reported to enhance allergenicity compared with the allergens in similar vehicles without liposomes. The present report includes data on more sensitization studies using the mouse local lymph node assay with three contact allergens encapsulated in different dermal drug-delivery systems: liposomes, ethosomes, and polycaprolactone particles. The results show that the drug-delivery systems are not sensitizers in themselves. Encapsulating the hydrophilic contact allergen potassium dichromate in all three drug-delivery systems did not affect the sensitizing capacity of potassium dichromate compared with control solutions. However, encapsulating the lipophilic contact allergen dinitrochlorobenzene (DNCB) in polycaprolactone reduced the sensitizing capacity to 1211 ± 449 compared with liposomes (7602 ± 2658) and in acetone:olive oil (4:1) (5633 ± 666). The same trend was observed for encapsulating isoeugenol in polycaprolactone (1100 ± 406) compared with a formulation in acetone:olive oil (4491 ± 819) and in liposomes (3668 ± 950). Further, the size of DNCB-loaded liposomes did not affect the sensitizing properties. These results suggest that modern dermal drug-delivery systems may in some cases magnify or decrease the sensitizing capacity of the encapsulated contact allergen.

  1. Feasibility of binary composition in development of nanoethosomal glycolic vesicles of triamcinolone acetonide using Box-behnken design: in vitro and ex vivo characterization.

    Science.gov (United States)

    Akhtar, Nida; Verma, Anurag; Pathak, Kamla

    2017-09-01

    Triamcinolone acetonide (TA) employed for the treatment of atopic dermatitis exhibits limited penetration into the epidermis. This investigation aimed to explore the role of binary solvents in topical drug delivery of TA by developing nanoethosomal glycolic lipid vesicles by infusion method. Screening of vesicles (TA1-TA17) formulated by Box Behnken design identified the optimized formulation (TA10) that was developed as carbomer gels. The gels were then evaluated for pharmaceutical properties and compared with control and reference ethosomal gel (RG). Higher in vitro permeation was found in gels containing TA10, prepared with or without using penetration enhancer (EGP 83.76 ± 0.72% and EG 82.42 ± 0.89%, respectively). CLSM studies depicted deeper uniform penetration of fluorescent tracer into the epidermis via EG as compared with RG and control gel. Enhanced penetration was due to combinational solvent effect exerted by ethanol and propylene glycol. Histological analysis confirmed the non-irritant potential of the gel. Thus, it can be concluded that nanoethosomal glycolic vesicles proved to be an effective non irritant carrier for improvised penetration of triamcinolone acetonide for potential topical therapeutics.

  2. Preparation and Characterization of Binary Organogels via Some Azobenzene Amino Derivatives and Different Fatty Acids: Self-Assembly and Nanostructures

    OpenAIRE

    Haiying Guo; Tifeng Jiao; Xihai Shen; Qingrui Zhang; Adan Li; Faming Gao

    2014-01-01

    In present work the gelation behaviors of binary organogels composed of azobenzene amino derivatives and fatty acids with different alkyl chains in various organic solvents were designed and investigated. Their gelation behaviors in 20 solvents were tested as new binary organic gelators. It showed that the length of alkyl substituent chains and azobenzene segment have played a crucial role in the gelation behavior of all gelator mixtures in various organic solvents. Longer alkyl chains in mol...

  3. Preparation and Characterization of Binary Organogels via Some Azobenzene Amino Derivatives and Different Fatty Acids: Self-Assembly and Nanostructures

    Directory of Open Access Journals (Sweden)

    Haiying Guo

    2014-01-01

    Full Text Available In present work the gelation behaviors of binary organogels composed of azobenzene amino derivatives and fatty acids with different alkyl chains in various organic solvents were designed and investigated. Their gelation behaviors in 20 solvents were tested as new binary organic gelators. It showed that the length of alkyl substituent chains and azobenzene segment have played a crucial role in the gelation behavior of all gelator mixtures in various organic solvents. Longer alkyl chains in molecular skeletons in present gelators are favorable for the gelation of organic solvents. Morphological studies revealed that the gelator molecules self-assemble into different aggregates from lamella, wrinkle, to belt with change of solvents. Spectral studies indicated that there existed different H-bond formation and hydrophobic force, depending on different substituent chains in molecular skeletons. The present work may also give new perspectives for designing new binary organogelators and soft materials.

  4. Self-Assembly and Soft Material Preparation of Binary Organogels via Aminobenzimidazole/Benzothiazole and Acids with Different Alkyl Substituent Chains

    Directory of Open Access Journals (Sweden)

    Tifeng Jiao

    2013-01-01

    Full Text Available The gelation behaviors of binary organogels composed of aminobenzimidazole/benzothiazole derivatives and benzoic acid with single-/multialkyl substituent chain in various organic solvents were designed and investigated. Their gelation behaviors in 20 solvents were tested as new binary organic gelators. This showed that the number and length of alkyl substituent chains and benzimidazole/benzothiazole segment have played a crucial role in the gelation behavior of all gelator mixtures in various organic solvents. More alkyl chains in molecular skeletons in present gelators are favorable for the gelation of organic solvents. The length of alkyl substituent chains has also played an important role in changing the gelation behaviors and assembly states. Morphological studies revealed that the gelator molecules self-assemble into different aggregates from wrinkle, lamella, belt, to fiber with change of solvents. Spectral studies indicated that there existed different H-bond formation and hydrophobic force, depending on benzimidazole/benzothiazole segment and alkyl substituent chains in molecular skeletons. The prepared nanostructured materials have wide perspectives and many potential applications in nanoscience and material fields due to their scientific values. The present work may also give new clues for designing new binary organogelators and soft materials.

  5. Investigations of RF magnetron sputtered CZTS absorber layer thin films prepared using sulfur induced binary targets without sulfurization

    Science.gov (United States)

    Balaji, G.; Balasundaraprabhu, R.; Prasanna, S.; Prabavathy, N.; McIlroy, D. N.; Kannan, M. D.

    2018-01-01

    Thin films of copper zinc tin sulfide (CZTS), a quaternary semiconductor, was deposited onto well-cleaned soda lime glass substrates using binary sulfur based sputtering targets - copper sulfide (CuS), zinc sulfide (ZnS), and tin sulfide (SnS) by RF Magnetron Sputtering at 300 °C. The stacking order of ZnS/CuS/SnS was used to deposit CZTS thin films. The composition of CZTS thin films were confirmed using X- Ray photoelectron spectroscopy (XPS) and the atomic ratio of the individual elements were quantitatively estimated. X-ray diffraction (XRD) studies were used to understand the CZTS phase formation and the presence of CZTS kesterite phase along direction was detected with the secondary phase of SnS and ZnS. XRD results were validated with Raman results were the presence of CZTS and SnS was corroborated. The optical properties of CZTS thin films were studied using UV-Vis-NIR spectrophotometer where the optical band gap was 1.46 eV and as well as other optical parameters such as interference and optical band gap were ascertained and the results are discussed.

  6. Preparation of gold-containing binary metal clusters by co-deposition-precipitation method and for hydrogenation of chloronitrobenzene

    OpenAIRE

    Ya-Ting Tsu; Yu-Wen Chen

    2017-01-01

    Nano-gold catalyst has been reported to have high activity and selectivity for liquid phase hydrogenation reaction. In this study, gold-containing bimetals were loaded on TiO2. For bimetallic catalysts, gold and different metals were prepared by the deposition-precipitation method, and then used NaBH4 to reduce metal cations. The catalysts were characterized by X-ray diffraction, transmission electron microscopy, high resolution transmission electron microscopy, and X-ray photoelectron spectr...

  7. Preparation of PLLA/PMMA and PLLA/PS binary blend nanoparticles by incorporation of PLLA in methyl methacrylate or styrene miniemulsion homopolymerization

    Directory of Open Access Journals (Sweden)

    Luana Becker Peres

    2015-02-01

    Full Text Available Miniemulsion homopolymerization reactions of methyl methacrylate (MMA and styrene (STY using poly(L-lactide as co-stabilizer were carried out in order to prepare poly(L-lactide/poly(methyl methacrylate (PLLA/PMMA and poly(L-lactide/polystyrene (PLLA/PS binary blend nanoparticles. The effect of PLLA concentration on methyl methacrylate (MMA and styrene (STY homopolymerization reactions was evaluated. It was found that the incorporation of PLLA resulted on acceleration of MMA and STY homopolymerization reactions and led to a molar mass increase of up to 70% for PS in PLLA/PS blend nanoparticles in relation to those prepared without PLLA, which can be attributed to an increase of reaction loci viscosity (gel effect. PLLA also acted as an efficient co-stabilizer, since it was able to retard diffusional degradation of droplets when no other kind of co-stabilizer was used. Two isolated Tgs were found in both PLLA/PMMA and PLLA/PS blend nanoparticles which can be associated to blend immiscibility. TEM images corroborate these results, suggesting that immiscible PLLA/PMMA and PLLA/PS blend nanoparticles could be formed with two segregated phases and core-shell morphology.

  8. Preparation of gold-containing binary metal clusters by co-deposition-precipitation method and for hydrogenation of chloronitrobenzene

    Directory of Open Access Journals (Sweden)

    Ya-Ting Tsu

    2017-06-01

    Full Text Available Nano-gold catalyst has been reported to have high activity and selectivity for liquid phase hydrogenation reaction. In this study, gold-containing bimetals were loaded on TiO2. For bimetallic catalysts, gold and different metals were prepared by the deposition-precipitation method, and then used NaBH4 to reduce metal cations. The catalysts were characterized by X-ray diffraction, transmission electron microscopy, high resolution transmission electron microscopy, and X-ray photoelectron spectroscopy. The catalytic properties of these catalysts were tested by hydrogenation of p-chloronitrobenzene (p-CNB in a batch reactor at 1.1 MPa H2 pressure, 373 K and 500 rpm. Cu, Ag, Ru, and Pd formed nano-alloy with Au. In addition, Cu–Au, Ag–Au, and Ru–Au alloy had Cu-, Ag-, and Ru-enriched surface, respectively. Instead, Pd–Au alloy had Pd-enriched surface. There are two kinds of alloy effects: (1 geometric effects, i.e., the surface-enriched metal would change the distance of Au–Au atoms that is required for facilitating the hydrogenation of chloronitrobenzene; and (2 electronic effects, which involve charge transfer between the metals. The activity decreased in the following order: PdAu/TiO2 > Au/TiO2 > NiAu/TiO2 > AgAu/TiO2 > RuAu/TiO2 > CuAu/TiO2. Comparing with other metals, adding Pd in Au showed a higher activity. Adding palladium could reduce gold-valence state, and increased active sites for reaction.

  9. Interacting binaries

    CERN Document Server

    Shore, S N; van den Heuvel, EPJ

    1994-01-01

    This volume contains lecture notes presented at the 22nd Advanced Course of the Swiss Society for Astrophysics and Astronomy. The contributors deal with symbiotic stars, cataclysmic variables, massive binaries and X-ray binaries, in an attempt to provide a better understanding of stellar evolution.

  10. Facile preparation of 3D hierarchical coaxial-cable-like Ni-CNTs@beta-(Ni, Co) binary hydroxides for supercapacitors with ultrahigh specific capacitance.

    Science.gov (United States)

    Zhang, Manyu; Ma, Xiaowei; Bi, Han; Zhao, Xuebing; Wang, Chao; Zhang, Jie; Li, Yuesheng; Che, Renchao

    2017-09-15

    A facile chemical method for Co doping Ni-CNTs@α-Ni(OH) 2 combining with an in situ phase transformation process is successfully proposed and employed to synthesize three-dimensional (3D) hierarchical Ni-CNTs@β-(Ni, Co) binary hydroxides. This strategy can effectively maintain the coaxial-cable-like structure of Ni-CNTs@α-Ni(OH) 2 and meanwhile increase the content of Co as much as possible. Eventually, the specific capacitances and electrical conductivity of the composites are remarkably enhanced. The optimized composite exhibits high specific capacitances of 2861.8F g -1 at 1A g -1 (39.48F cm -2 at 15mAcm -2 ), good rate capabilities of 1221.8F g -1 at 20A g -1 and cycling stabilities (87.6% of capacitance retention after 5000cycles at 5A g -1 ). The asymmetric supercapacitor (ASC) constructed with the as-synthesized composite and activated carbon as positive and negative electrode delivers a high specific capacitance of 287.7F g -1 at 1A g -1 . The device demonstrates remarkable energy density (96Whkg -1 ) and high power density (15829.4Wkg -1 ). The retention of capacitance remains 83.5% at the current density of 5A g -1 after 5000cycles. The charged and discharged samples are further studied by ex situ electron energy loss spectroscopy (EELS) analysis, XRD and SEM to figure out the reasons of capacitance fading. Overall, it is believable that this facile synthetic strategy can be applied to prepare various nanostructured metal hydroxide/CNT composites for high performance supercapacitor electrode materials. Copyright © 2017. Published by Elsevier Inc.

  11. Preparation

    Directory of Open Access Journals (Sweden)

    M.M. Dardir

    2014-03-01

    Full Text Available Some hexanamide-mono and di-linoleniate esters were prepared by the reaction of linolenic acid and hexanamide (derived from the reaction of hexanoic acid and diethanolamine. The chemical structure for the newly prepared hexanamide-mono and di-linoleniate esters were elucidated using elemental analysis, (FTIR, H 1NMR and chemical ionization mass spectra (CI/Ms spectroscopic techniques. The results of the spectroscopic analysis indicated that they were prepared through the right method and they have high purity. The new prepared esters have high biodegradability and lower toxicity (environmentally friendly so they were evaluated as a synthetic-based mud (ester-based mud for oil-well drilling fluids. The evaluation included study of the rheological properties, filtration and thermal properties of the ester based-muds formulated with the newly prepared esters compared to the reference commercial synthetic-based mud.

  12. Study on effect of L-arginine on solubility and dissolution of Zaltoprofen: Preparation and characterization of binary and ternary cyclodextrin inclusion complexes

    Science.gov (United States)

    Sherje, Atul P.; Patel, Forum; Murahari, Manikanta; Suvarna, Vasanti; Patel, Kavitkumar

    2018-02-01

    The present study demonstrated the binary and ternary complexes of Zaltoprofen (ZPF) with β-CD and HP-β-CD. The products were characterized using solubility, in vitro dissolution, and DSC studies. The mode of interaction of guest and host was revealed through 1H NMR and FT-IR studies. A significant increase was noticed in the stability constant (Kc) and complexation efficiency (CE) of β-CD and HP-β-CD due to addition of L-Arg in ternary complexes. The ternary complexes showed greater increase in solubility and dissolution of ZPF than binary complexes. Thus, ternary system of ZPF could be an innovative approach for its solubility and dissolution enhancement.

  13. Preparation, structural characterization, and in vitro cell studies of three-dimensional SiO2-CaO binary glass scaffolds built ofultra-small nanofibers.

    Science.gov (United States)

    Luo, Honglin; Li, Wei; Ao, Haiyong; Li, Gen; Tu, Junpin; Xiong, Guangyao; Zhu, Yong; Wan, Yizao

    2017-07-01

    Three-dimensional (3D) nanofibrous scaffolds hold great promises in tissue engineering and regenerative medicine. In this work, for the first time, 3D SiO 2 -CaO binary glass nanofibrous scaffolds have been fabricated via a combined method of template-assisted sol-gel and calcination by using bacterial cellulose as the template. SEM with EDS, TEM, and AFM confirm that the molar ratio of Ca to Si and fiber diameter of the resultant SiO 2 -CaO nanofibers can be controlled by immersion time in the solution of tetraethyl orthosilicate and ethanol. The optimal immersion time was 6h which produced the SiO 2 -CaO binary glass containing 60at.% Si and 40at.% Ca (named 60S40C). The fiber diameter of 60S40C scaffold is as small as 29nm. In addition, the scaffold has highly porous 3D nanostructure with dominant mesopores at 10.6nm and macropores at 20μm as well as a large BET surface area (240.9m 2 g -1 ), which endow the 60S40C scaffold excellent biocompatibility and high ALP activity as revealed by cell studies using osteoblast cells. These results suggest that the 60S40C scaffold has great potential in bone tissue regeneration. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Testing theory of binary evolution with interacting binary stars

    Science.gov (United States)

    Ergma, E.; Sarna, M. J.

    2002-01-01

    Of particular interest to us is the study of mass loss and its influence on the evolution of a binary systems. For this we use theoretical evolutionary models, which include: mass accretion, mass loss, novae explosion, super--efficient wind, and mixing processes. To test our theoretical prediction we proposed to determine the 12C / 13C ratio via measurements of the 12CO and 13CO bands around 2.3 micron. The available observations (Exter at al. 2001, in preparation) show good agreement with the theoretical predictions (Sarna 1992), for Algol-type binaries. Our preliminary estimates of the isotopic ratios for pre-CV's and CV's (Catalan et al. 2000, Dhillon et al. 2001) agree with the theoretical predictions from the common--envelope binary evolution models by Sarna et al. (1995). For the SXT we proposed (Ergma & Sarna 2001) similar observational test, which has not been done yet.

  15. Preparation of magnetic indole-3-acetic acid imprinted polymer beads with 4-vinylpyridine and β-cyclodextrin as binary monomer via microwave heating initiated polymerization and their application to trace analysis of auxins in plant tissues.

    Science.gov (United States)

    Zhang, Yi; Li, Yuanwen; Hu, Yuling; Li, Gongke; Chen, Yueqin

    2010-11-19

    Auxin is a crucial phytohormone for precise control of growth and development of plants. Due to its low concentration in plant tissues which are rich in interfering substances, the accurate determination of auxins remains a challenge. In this paper, a new strategy for isolation and enrichment of auxins from plant tissues was obtained by the magnetic molecularly imprinted polymer (mag-MIP) beads, which were prepared by microwave heating initiated suspension polymerization using indole-3-acetic acid (IAA) as template. In order to obtain higher selective recognition cavities, an enhanced imprinting method based on binary functional monomers, 4-vinylpyridine (4-VP) and β-cyclodextrin (β-CD), was adopted for IAA imprinting. The morphological and magnetic characteristics of the mag-MIP beads were characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy and vibrating sample magnetometry. A majority of resultant beads were within the size range of 80-150μm. Porous surface morphology and good magnetic property were observed. Furthermore, the mag-MIP beads fabricated with 4-VP and β-CD as binary functional monomers exhibited improved recognition ability to IAA, as compared with the mag-MIP beads prepared with the individual monomer separately. Competitive rebinding experiment results revealed that the mag-MIP beads exhibited a higher specific recognition for the template than the non-imprinted polymer (mag-NIP) beads. An extraction method by mag-MIP beads coupled with high performance liquid chromatography (HPLC) was developed for determination of IAA and indole-3-butyric acid (IBA) in plant tissues. Linear ranges for IAA and IBA were in the range of 7.00-100.0μgL(-1) and 10.0-100.0μgL(-1), and the detection limits were 3.9 and 7.4μgL(-1), respectively. The analytical performance was also estimated by seedlings or immature embryos samples from three different plant tissues, pea, rice and wheat. Recoveries were in the range of 70

  16. Magnetic binary nanofillers

    Energy Technology Data Exchange (ETDEWEB)

    Morales Mendoza, N. [INQUIMAE, CONICET-UBA, Ciudad Universitaria, Pab2, (C1428EHA) Bs As (Argentina); LPyMC, Dep. De Fisica, FCEN-UBA and IFIBA -CONICET, Ciudad Universitaria, Cap. Fed. (Argentina); Goyanes, S. [LPyMC, Dep. De Fisica, FCEN-UBA and IFIBA -CONICET, Ciudad Universitaria, Cap. Fed. (Argentina); Chiliotte, C.; Bekeris, V. [LBT, Dep. De Fisica, FCEN-UBA. Ciudad Universitaria, Pab1, C1428EGA CABA (Argentina); Rubiolo, G. [LPyMC, Dep. De Fisica, FCEN-UBA and IFIBA -CONICET, Ciudad Universitaria, Cap. Fed. (Argentina); Unidad de Actividad Materiales, CNEA, Av Gral. Paz 1499, San Martin (1650), Prov. de Bs As (Argentina); Candal, R., E-mail: candal@qi.fcen.uba.ar [INQUIMAE, CONICET-UBA, Ciudad Universitaria, Pab2, (C1428EHA) Bs As (Argentina); Escuela de Ciencia y Tecnologia, 3iA, Universidad de Gral. San Martin, San Martin, Prov. Bs As (Argentina)

    2012-08-15

    Magnetic binary nanofillers containing multiwall carbon nanotubes (MWCNT) and hercynite were synthesized by Chemical Vapor Deposition (CVD) on Fe/AlOOH prepared by the sol-gel method. The catalyst precursor was fired at 450 Degree-Sign C, ground and sifted through different meshes. Two powders were obtained with different particle sizes: sample A (50-75 {mu}m) and sample B (smaller than 50 {mu}m). These powders are composed of iron oxide particles widely dispersed in the non-crystalline matrix of aluminum oxide and they are not ferromagnetic. After reduction process the powders are composed of {alpha}-Fe nanoparticles inside hercynite matrix. These nanofillers are composed of hercynite containing {alpha}-Fe nanoparticles and MWCNT. The binary magnetic nanofillers were slightly ferromagnetic. The saturation magnetization of the nanofillers depended on the powder particle size. The nanofiller obtained from powder particles in the range 50-75 {mu}m showed a saturation magnetization 36% higher than the one formed from powder particles smaller than 50 {mu}m. The phenomenon is explained in terms of changes in the magnetic environment of the particles as consequence of the presence of MWCNT.

  17. An alternative sol-gel route for the preparation of thin films in CeO2-TiO2 binary system

    International Nuclear Information System (INIS)

    Kidchob, Tongjit; Malfatti, Luca; Marongiu, Daniela; Enzo, Stefano; Innocenzi, Plinio

    2010-01-01

    Thin films of titania-ceria have been prepared via sol-gel processing by employing titanium and cerium chloride compounds in highly acidic conditions for the precursor sol. This sol-gel route allows obtaining titania-ceria and cerium titanate films, CeTi 2 O 6 , after thermal treatment in air. The films exhibit a high optical transparency which is modulated by controlling the composition and the thermal treatment. The materials have been characterized by X-ray diffraction, UV-visible spectroscopy, ellipsometric spectroscopy and atomic force microscopy. The titania-ceria films show, as a function of the composition, the formation of different phases after thermal treatment in air at 800 o C. In particular, with the composition Ce25-Ti75 we have obtained a pure cerium titanate phase, CeTi 2 O 6 , which can be formed only in a very strict range of compositions.

  18. An alternative sol-gel route for the preparation of thin films in CeO{sub 2}-TiO{sub 2} binary system

    Energy Technology Data Exchange (ETDEWEB)

    Kidchob, Tongjit; Malfatti, Luca; Marongiu, Daniela [Laboratorio di Scienza dei Materiali e Nanotecnologie, D.A.P., Universita di Sassari and CR-INSTM, Palazzo Pou Salid, Piazza Duomo 6, 07041 Alghero (Italy); Enzo, Stefano [Dipartimento di Chimica, Universita di Sassari, Via Vienna 2, 07100 Sassari (Italy); Innocenzi, Plinio, E-mail: plinio@uniss.i [Laboratorio di Scienza dei Materiali e Nanotecnologie, D.A.P., Universita di Sassari and CR-INSTM, Palazzo Pou Salid, Piazza Duomo 6, 07041 Alghero (Italy)

    2010-01-01

    Thin films of titania-ceria have been prepared via sol-gel processing by employing titanium and cerium chloride compounds in highly acidic conditions for the precursor sol. This sol-gel route allows obtaining titania-ceria and cerium titanate films, CeTi{sub 2}O{sub 6}, after thermal treatment in air. The films exhibit a high optical transparency which is modulated by controlling the composition and the thermal treatment. The materials have been characterized by X-ray diffraction, UV-visible spectroscopy, ellipsometric spectroscopy and atomic force microscopy. The titania-ceria films show, as a function of the composition, the formation of different phases after thermal treatment in air at 800 {sup o}C. In particular, with the composition Ce25-Ti75 we have obtained a pure cerium titanate phase, CeTi{sub 2}O{sub 6}, which can be formed only in a very strict range of compositions.

  19. Solving a binary puzzle

    NARCIS (Netherlands)

    P.H. Utomo (Putranto); R.H. Makarim (Rusydi)

    2017-01-01

    textabstractA Binary puzzle is a Sudoku-like puzzle with values in each cell taken from the set (Formula presented.). Let (Formula presented.) be an even integer, a solved binary puzzle is an (Formula presented.) binary array that satisfies the following conditions: (1) no three consecutive ones and

  20. Eclipsing binaries in open clusters

    DEFF Research Database (Denmark)

    Southworth, John; Clausen, J.V.

    2006-01-01

    Stars: fundamental parameters - Stars : binaries : eclipsing - Stars: Binaries: spectroscopic - Open clusters and ass. : general Udgivelsesdato: 5 August......Stars: fundamental parameters - Stars : binaries : eclipsing - Stars: Binaries: spectroscopic - Open clusters and ass. : general Udgivelsesdato: 5 August...

  1. Interacting binary stars

    CERN Document Server

    Sahade, Jorge; Ter Haar, D

    1978-01-01

    Interacting Binary Stars deals with the development, ideas, and problems in the study of interacting binary stars. The book consolidates the information that is scattered over many publications and papers and gives an account of important discoveries with relevant historical background. Chapters are devoted to the presentation and discussion of the different facets of the field, such as historical account of the development in the field of study of binary stars; the Roche equipotential surfaces; methods and techniques in space astronomy; and enumeration of binary star systems that are studied

  2. Binary Masking & Speech Intelligibility

    DEFF Research Database (Denmark)

    Boldt, Jesper

    The purpose of this thesis is to examine how binary masking can be used to increase intelligibility in situations where hearing impaired listeners have difficulties understanding what is being said. The major part of the experiments carried out in this thesis can be categorized as either experime......The purpose of this thesis is to examine how binary masking can be used to increase intelligibility in situations where hearing impaired listeners have difficulties understanding what is being said. The major part of the experiments carried out in this thesis can be categorized as either...... experiments under ideal conditions or as experiments under more realistic conditions useful for real-life applications such as hearing aids. In the experiments under ideal conditions, the previously defined ideal binary mask is evaluated using hearing impaired listeners, and a novel binary mask -- the target...... binary mask -- is introduced. The target binary mask shows the same substantial increase in intelligibility as the ideal binary mask and is proposed as a new reference for binary masking. In the category of real-life applications, two new methods are proposed: a method for estimation of the ideal binary...

  3. A Comparative Study of the Compaction Properties of Binary and ...

    African Journals Online (AJOL)

    Purpose: To comparatively evaluate the tableting properties of binary mixtures and bilayer tablets containing plastic deformation and brittle fracture excipients. Methods: Binary mixture and bilayer tablets of microcrystalline cellulose (MCC), ethyl cellulose, anhydrous lactose and dextrate were prepared by direct compression ...

  4. Binary effectivity rules

    DEFF Research Database (Denmark)

    Keiding, Hans; Peleg, Bezalel

    2006-01-01

    effectivity rule is regular if it is the effectivity rule of some regular binary SCR. We characterize completely the family of regular binary effectivity rules. Quite surprisingly, intrinsically defined von Neumann-Morgenstern solutions play an important role in this characterization...

  5. Binary colloidal crystals

    NARCIS (Netherlands)

    Christova-Zdravkova, C.G.

    2005-01-01

    Binary crystals are crystals composed of two types of particles having different properties like size, mass density, charge etc. In this thesis several new approaches to make binary crystals of colloidal particles that differ in size, material and charge are reported We found a variety of crystal

  6. BINARY MINOR PLANETS

    Data.gov (United States)

    National Aeronautics and Space Administration — The data set lists orbital and physical properties for well-observed or suspected binary/multiple minor planets including the Pluto system, compiled from the...

  7. Close binary stars

    International Nuclear Information System (INIS)

    Larsson-Leander, G.

    1979-01-01

    Studies of close binary stars are being persued more vigorously than ever, with about 3000 research papers and notes pertaining to the field being published during the triennium 1976-1978. Many major advances and spectacular discoveries were made, mostly due to increased observational efficiency and precision, especially in the X-ray, radio, and ultraviolet domains. Progress reports are presented in the following areas: observational techniques, methods of analyzing light curves, observational data, physical data, structure and models of close binaries, statistical investigations, and origin and evolution of close binaries. Reports from the Coordinates Programs Committee, the Committee for Extra-Terrestrial Observations and the Working Group on RS CVn binaries are included. (Auth./C.F.)

  8. Binary and ternary systems

    International Nuclear Information System (INIS)

    Petrov, D.A.

    1986-01-01

    Conditions for thermodynamical equilibrium in binary and ternary systems are considered. Main types of binary and ternary system phase diagrams are sequently constructed on the basis of general regularities on the character of transition from one equilibria to others. New statements on equilibrium line direction in the diagram triple points and their isothermal cross sections are developed. New represenations on equilibria in case of monovariant curve minimum and maximum on three-phase equilibrium formation in ternary system are introduced

  9. Binary and Millisecond Pulsars

    OpenAIRE

    Lorimer, D. R.

    2005-01-01

    We review the main properties, demographics and applications of binary and millisecond radio pulsars. Our knowledge of these exciting objects has greatly increased in recent years, mainly due to successful surveys which have brought the known pulsar population to over 1800. There are now 83 binary and millisecond pulsars associated with the disk of our Galaxy, and a further 140 pulsars in 26 of the Galactic globular clusters. Recent highlights include the discovery of the young relativistic b...

  10. Astrophysics of white dwarf binaries

    NARCIS (Netherlands)

    Nelemans, G.A.

    2006-01-01

    White dwarf binaries are the most common compact binaries in the Universe and are especially important for low-frequency gravitational wave detectors such as LISA. There are a number of open questions about binary evolution and the Galactic population of white dwarf binaries that can be solved using

  11. Evolution of cataclysmic binaries

    International Nuclear Information System (INIS)

    Paczynski, B.

    1981-01-01

    Cataclysmic binaries with short orbital periods have low mass secondary components. Their nuclear time scale is too long to be of evolutionary significance. Angular momentum loss from the binary drives the mass transfer between the two components. As long as the characteristic time scale is compared with the Kelvin-Helmholtz time scale of the mass losing secondary the star remains close to the main sequence, and the binary period decreases with time. If angular momentum loss is due to gravitational radiation then the mass transfer time scale becomes comparable to the Kelvin-Helmoltz time scale when the secondary's mass decreases to 0.12 Msub(sun), and the binary period is reduced to 80 minutes. Later, the mass losing secondary departs from the main sequence and gradually becomes degenerate. Now the orbital period increases with time. The observed lower limit to the orbital periods of hydrogen rich cataclysmic binaries implies that gravitational radiation is the main driving force for the evolution of those systems. It is shown that binaries emerging from a common envelope phase of evolution are well detached. They have to lose additional angular momentum to become semidetached cataclysmic variables. (author)

  12. Binary Neutron Star Mergers

    Directory of Open Access Journals (Sweden)

    Joshua A. Faber

    2012-07-01

    Full Text Available We review the current status of studies of the coalescence of binary neutron star systems. We begin with a discussion of the formation channels of merging binaries and we discuss the most recent theoretical predictions for merger rates. Next, we turn to the quasi-equilibrium formalisms that are used to study binaries prior to the merger phase and to generate initial data for fully dynamical simulations. The quasi-equilibrium approximation has played a key role in developing our understanding of the physics of binary coalescence and, in particular, of the orbital instability processes that can drive binaries to merger at the end of their lifetimes. We then turn to the numerical techniques used in dynamical simulations, including relativistic formalisms, (magneto-hydrodynamics, gravitational-wave extraction techniques, and nuclear microphysics treatments. This is followed by a summary of the simulations performed across the field to date, including the most recent results from both fully relativistic and microphysically detailed simulations. Finally, we discuss the likely directions for the field as we transition from the first to the second generation of gravitational-wave interferometers and while supercomputers reach the petascale frontier.

  13. Skewed Binary Search Trees

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Moruz, Gabriel

    2006-01-01

    It is well-known that to minimize the number of comparisons a binary search tree should be perfectly balanced. Previous work has shown that a dominating factor over the running time for a search is the number of cache faults performed, and that an appropriate memory layout of a binary search tree...... can reduce the number of cache faults by several hundred percent. Motivated by the fact that during a search branching to the left or right at a node does not necessarily have the same cost, e.g. because of branch prediction schemes, we in this paper study the class of skewed binary search trees....... For all nodes in a skewed binary search tree the ratio between the size of the left subtree and the size of the tree is a fixed constant (a ratio of 1/2 gives perfect balanced trees). In this paper we present an experimental study of various memory layouts of static skewed binary search trees, where each...

  14. Modelling binary data

    CERN Document Server

    Collett, David

    2002-01-01

    INTRODUCTION Some Examples The Scope of this Book Use of Statistical Software STATISTICAL INFERENCE FOR BINARY DATA The Binomial Distribution Inference about the Success Probability Comparison of Two Proportions Comparison of Two or More Proportions MODELS FOR BINARY AND BINOMIAL DATA Statistical Modelling Linear Models Methods of Estimation Fitting Linear Models to Binomial Data Models for Binomial Response Data The Linear Logistic Model Fitting the Linear Logistic Model to Binomial Data Goodness of Fit of a Linear Logistic Model Comparing Linear Logistic Models Linear Trend in Proportions Comparing Stimulus-Response Relationships Non-Convergence and Overfitting Some other Goodness of Fit Statistics Strategy for Model Selection Predicting a Binary Response Probability BIOASSAY AND SOME OTHER APPLICATIONS The Tolerance Distribution Estimating an Effective Dose Relative Potency Natural Response Non-Linear Logistic Regression Models Applications of the Complementary Log-Log Model MODEL CHECKING Definition of Re...

  15. Evolution of dwarf binaries

    International Nuclear Information System (INIS)

    Tutukov, A.V.; Fedorova, A.V.; Yungel'son, L.R.

    1982-01-01

    The conditions of mass exchange in close binary systems with masses of components less or equal to one solar mass have been analysed for the case, when the system radiates gravitational waves. It has been shown that the mass exchange rate depends in a certain way on the mass ratio of components and on the mass of component that fills its inner critical lobe. The comparison of observed periods, masses of contact components, and mass exchange rates of observed cataclysmic binaries have led to the conclusion that the evolution of close binaries WZ Sge, OY Car, Z Cha, TT Ari, 2A 0311-227, and G 61-29 may be driven by the emission of gravitational waves [ru

  16. Evolution of dwarf binaries

    International Nuclear Information System (INIS)

    Tutukov, A.V.; Fedorova, A.V.; Yungel'son, L.R.

    1982-01-01

    The circumstances of mass exchange in close binary systems whose components have a mass < or approx. =1 M/sub sun/ are analyzed for the case where the system is losing orbital angular momentum by radiation of gravitational waves. The mass exchange rate will depend on the mass ratio of the components and on the mass of the component that is overfilling its critical Roche lobe. A comparison of the observed orbital periods, masses of the components losing material, and mass exchange rates against the theoretical values for cataclysmic binaries indicates that the evolution of the close binaries WZ Sge, OY Car, Z Cha, TT Ari, 2A 0311-227, and G61-29 may be driven by the emission of gravitational waves

  17. Binary and Millisecond Pulsars

    Directory of Open Access Journals (Sweden)

    Lorimer Duncan R.

    2008-11-01

    Full Text Available We review the main properties, demographics and applications of binary and millisecond radio pulsars. Our knowledge of these exciting objects has greatly increased in recent years, mainly due to successful surveys which have brought the known pulsar population to over 1800. There are now 83 binary and millisecond pulsars associated with the disk of our Galaxy, and a further 140 pulsars in 26 of the Galactic globular clusters. Recent highlights include the discovery of the young relativistic binary system PSR J1906+0746, a rejuvination in globular cluster pulsar research including growing numbers of pulsars with masses in excess of 1.5M_⊙, a precise measurement of relativistic spin precession in the double pulsar system and a Galactic millisecond pulsar in an eccentric (e = 0.44 orbit around an unevolved companion.

  18. The Brightest Binaries

    Science.gov (United States)

    Vanbeveren, D., Van Rensbergen, W., De Loore, C.

    Massive stars are distributed all over the upper part of the Hertzsprung-Russell diagram according to their subsequent phases of stellar evolution from main sequence to supernova. Massive stars may either be single or they may be a component of a close binary. The observed single star/binary frequency is known only in a small part of the Galaxy. Whether this holds for the whole galaxy or for the whole cosmos is questionable and needs many more high quality observations. Massive star evolution depends critically on mass loss by stellar wind and this stellar wind mass loss may change dramatically when stars evolve from one phase to another. We start the book with a critical discussion of observations of the different types of massive stars, observations that are of fundamental importance in relation to stellar evolution, with special emphasis on mass loss by stellar wind. We update our knowledge of the physics that models the structure and evolution of massive single stars and we present new calculations. The conclusions resulting from a comparison between these calculations and observations are then used to study the evolution of massive binaries. This book provides our current knowledge of a great variety of massive binaries, and hence of a great variety of evolutionary phases. A large number of case studies illustrates the existence of these phases. Finally, we present the results of massive star population number synthesis, including the effect of binaries. The results indicate that neglecting them leads to a conclusion which may be far from reality. This book is written for researchers in massive star evolution. We hope that, after reading this book, university-level astrophysics students will become fascinated by the exciting world of the `Brightest Binaries'.

  19. Encounters of binaries

    International Nuclear Information System (INIS)

    Mikkola, S.

    1983-01-01

    Gravitational encounters of pairs of binaries have been studied numerically. Various cross-sections have been calculated for qualitative final results of the interaction and for energy transfer between the binding energy and the centre of mass kinetic energy. The distribution of the kinetic energies, resulting from the gravitational collision, were found to be virtually independent of the impact velocity in the case of collision of hard binaries. It was found that one out of five collisions, which are not simple fly-by's, leads to the formation of a stable three-body system. (author)

  20. Binary and Millisecond Pulsars

    Directory of Open Access Journals (Sweden)

    Duncan R. Lorimer

    1998-09-01

    Full Text Available Our knowledge of binary and millisecond pulsars has greatly increased in recent years. This is largely due to the success of large-area surveys which have brought the known population of such systems in the Galactic disk to around 50. As well as being interesting as a population of astronomical sources, many pulsars turn out to be superb celestial clocks. In this review we summarise the main properties of binary and millisecond pulsars and highlight some of their applications to relativistic astrophysics.

  1. Binary and Millisecond Pulsars

    Directory of Open Access Journals (Sweden)

    Lorimer Duncan R.

    2005-11-01

    Full Text Available We review the main properties, demographics and applications of binary and millisecond radio pulsars. Our knowledge of these exciting objects has greatly increased in recent years, mainly due to successful surveys which have brought the known pulsar population to over 1700. There are now 80 binary and millisecond pulsars associated with the disk of our Galaxy, and a further 103 pulsars in 24 of the Galactic globular clusters. Recent highlights have been the discovery of the first ever double pulsar system and a recent flurry of discoveries in globular clusters, in particular Terzan 5.

  2. Interacting binary stars

    International Nuclear Information System (INIS)

    Pringle, J.E.; Wade, R.A.

    1985-01-01

    This book reviews the theoretical and observational knowledge of interacting binary stars. The topics discussed embrace the following features of these objects: their orbits, evolution, mass transfer, angular momentum losses, X-ray emission, eclipses, variability, and other related phenomena. (U.K.)

  3. Equational binary decision diagrams

    NARCIS (Netherlands)

    J.F. Groote (Jan Friso); J.C. van de Pol (Jaco)

    2000-01-01

    textabstractWe incorporate equations in binary decision diagrams (BDD). The resulting objects are called EQ-BDDs. A straightforward notion of ordered EQ-BDDs (EQ-OBDD) is defined, and it is proved that each EQ-BDD is logically equivalent to an EQ-OBDD. Moreover, on EQ-OBDDs satisfiability and

  4. N-Bit Binary Resistor

    Science.gov (United States)

    Tcheng, Ping

    1989-01-01

    Binary resistors in series tailored to precise value of resistance. Desired value of resistance obtained by cutting appropriate traces across resistors. Multibit, binary-based, adjustable resistor with high resolution used in many applications where precise resistance required.

  5. Black holes in binary stars

    NARCIS (Netherlands)

    Wijers, R.A.M.J.

    1996-01-01

    Introduction Distinguishing neutron stars and black holes Optical companions and dynamical masses X-ray signatures of the nature of a compact object Structure and evolution of black-hole binaries High-mass black-hole binaries Low-mass black-hole binaries Low-mass black holes Formation of black holes

  6. Compressing Binary Decision Diagrams

    DEFF Research Database (Denmark)

    Hansen, Esben Rune; Satti, Srinivasa Rao; Tiedemann, Peter

    2008-01-01

    The paper introduces a new technique for compressing Binary Decision Diagrams in those cases where random access is not required. Using this technique, compression and decompression can be done in linear time in the size of the BDD and compression will in many cases reduce the size of the BDD to ......-2 bits per node. Empirical results for our compression technique are presented, including comparisons with previously introduced techniques, showing that the new technique dominate on all tested instances......The paper introduces a new technique for compressing Binary Decision Diagrams in those cases where random access is not required. Using this technique, compression and decompression can be done in linear time in the size of the BDD and compression will in many cases reduce the size of the BDD to 1...

  7. Compressing Binary Decision Diagrams

    DEFF Research Database (Denmark)

    Rune Hansen, Esben; Srinivasa Rao, S.; Tiedemann, Peter

    The paper introduces a new technique for compressing Binary Decision Diagrams in those cases where random access is not required. Using this technique, compression and decompression can be done in linear time in the size of the BDD and compression will in many cases reduce the size of the BDD to ......-2 bits per node. Empirical results for our compression technique are presented, including comparisons with previously introduced techniques, showing that the new technique dominate on all tested instances.......The paper introduces a new technique for compressing Binary Decision Diagrams in those cases where random access is not required. Using this technique, compression and decompression can be done in linear time in the size of the BDD and compression will in many cases reduce the size of the BDD to 1...

  8. Parametric binary dissection

    Science.gov (United States)

    Bokhari, Shahid H.; Crockett, Thomas W.; Nicol, David M.

    1993-01-01

    Binary dissection is widely used to partition non-uniform domains over parallel computers. This algorithm does not consider the perimeter, surface area, or aspect ratio of the regions being generated and can yield decompositions that have poor communication to computation ratio. Parametric Binary Dissection (PBD) is a new algorithm in which each cut is chosen to minimize load + lambda x(shape). In a 2 (or 3) dimensional problem, load is the amount of computation to be performed in a subregion and shape could refer to the perimeter (respectively surface) of that subregion. Shape is a measure of communication overhead and the parameter permits us to trade off load imbalance against communication overhead. When A is zero, the algorithm reduces to plain binary dissection. This algorithm can be used to partition graphs embedded in 2 or 3-d. Load is the number of nodes in a subregion, shape the number of edges that leave that subregion, and lambda the ratio of time to communicate over an edge to the time to compute at a node. An algorithm is presented that finds the depth d parametric dissection of an embedded graph with n vertices and e edges in O(max(n log n, de)) time, which is an improvement over the O(dn log n) time of plain binary dissection. Parallel versions of this algorithm are also presented; the best of these requires O((n/p) log(sup 3)p) time on a p processor hypercube, assuming graphs of bounded degree. How PBD is applied to 3-d unstructured meshes and yields partitions that are better than those obtained by plain dissection is described. Its application to the color image quantization problem is also discussed, in which samples in a high-resolution color space are mapped onto a lower resolution space in a way that minimizes the color error.

  9. Binary Masking & Speech Intelligibility

    OpenAIRE

    Boldt, Jesper

    2010-01-01

    The purpose of this thesis is to examine how binary masking can be used to increase intelligibility in situations where hearing impaired listeners have difficulties understanding what is being said. The major part of the experiments carried out in this thesis can be categorized as either experiments under ideal conditions or as experiments under more realistic conditions useful for real-life applications such as hearing aids. In the experiments under ideal conditions, the previously defined i...

  10. Formation and Evolution of Binary Systems Containing Collapsed Stars

    Science.gov (United States)

    Rappaport, Saul; West, Donald (Technical Monitor)

    2003-01-01

    This research includes theoretical studies of the formation and evolution of five types of interacting binary systems. Our main focus has been on developing a number of comprehensive population synthesis codes to study the following types of binary systems: (i) cataclysmic variables (#3, #8, #12, #15), (ii) low- and intermediate-mass X-ray binaries (#13, #20, #21), (iii) high-mass X-ray binaries (#14, #17, #22), (iv) recycled binary millisecond pulsars in globular clusters (#5, #10, #ll), and (v) planetary nebulae which form in interacting binaries (#6, #9). The numbers in parentheses refer to papers published or in preparation that are listed in this paper. These codes take a new unified approach to population synthesis studies. The first step involves a Monte Carlo selection of the primordial binaries, including the constituent masses, and orbital separations and eccentricities. Next, a variety of analytic methods are used to evolve the primary star to the point where either a dynamical episode of mass transfer to the secondary occurs (the common envelope phase), or the system evolves down an alternate path. If the residual core of the primary is greater than 2.5 solar mass, it will evolve to Fe core collapse and the production of a neutron star and a supernova explosion. In the case of systems involving neutron stars, a kick velocity is chosen randomly from an appropriate distribution and added to the orbital dynamics which determine the state of the binary system after the supernova explosion. In the third step, all binaries which commence stable mass transfer from the donor star (the original secondary in the binary system) to the compact object, are followed with a detailed binary evolution code. Finally, we include all the relevant dynamics of the binary system. For example, in the case of LMXBs, the binary system, with its recoil velocity from the supernova explosion, is followed in time through its path in the Galactic potential. For our globular cluster

  11. Massive Black Hole Binary Evolution

    Directory of Open Access Journals (Sweden)

    Merritt David

    2005-11-01

    Full Text Available Coalescence of binary supermassive black holes (SBHs would constitute the strongest sources of gravitational waves to be observed by LISA. While the formation of binary SBHs during galaxy mergers is almost inevitable, coalescence requires that the separation between binary components first drop by a few orders of magnitude, due presumably to interaction of the binary with stars and gas in a galactic nucleus. This article reviews the observational evidence for binary SBHs and discusses how they would evolve. No completely convincing case of a bound, binary SBH has yet been found, although a handful of systems (e.g. interacting galaxies; remnants of galaxy mergers are now believed to contain two SBHs at projected separations of <~ 1kpc. N-body studies of binary evolution in gas-free galaxies have reached large enough particle numbers to reproduce the slow, “diffusive” refilling of the binary’s loss cone that is believed to characterize binary evolution in real galactic nuclei. While some of the results of these simulations - e.g. the binary hardening rate and eccentricity evolution - are strongly N-dependent, others - e.g. the “damage” inflicted by the binary on the nucleus - are not. Luminous early-type galaxies often exhibit depleted cores with masses of ~ 1-2 times the mass of their nuclear SBHs, consistent with the predictions of the binary model. Studies of the interaction of massive binaries with gas are still in their infancy, although much progress is expected in the near future. Binary coalescence has a large influence on the spins of SBHs, even for mass ratios as extreme as 10:1, and evidence of spin-flips may have been observed.

  12. Adsorption of hexavalent chromium by graphite–chitosan binary ...

    Indian Academy of Sciences (India)

    Graphite chitosan binary (GCB) composite was prepared for hexavalent chromium adsorption from studied water. GCB was characterized by TGA, FTIR, SEM and X-ray diffraction techniques.Wide porous sorptive surface of 3.89 m 2 g − 1 and absorptive functionalities of GCB was due to 20% (w/w) graphite support on ...

  13. Adsorption of hexavalent chromium by graphite–chitosan binary

    Indian Academy of Sciences (India)

    Graphite chitosan binary (GCB) composite was prepared for hexavalent chromium adsorption from studied water. GCB was characterized by TGA, FTIR, SEM and X-ray diffraction techniques.Wide porous sorptive surface of 3.89 m 2 g − 1 and absorptive functionalities of GCB was due to 20% (w/w) graphite support on ...

  14. Contact Binary Asteroids

    Science.gov (United States)

    Rieger, Samantha

    2015-05-01

    Recent observations have found that some contact binaries are oriented such that the secondary impacts with the primary at a high inclination. This research investigates the evolution of how such contact binaries came to exist. This process begins with an asteroid pair, where the secondary lies on the Laplace plane. The Laplace plane is a plane normal to the axis about which the pole of a satellites orbit precesses, causing a near constant inclination for such an orbit. For the study of the classical Laplace plane, the secondary asteroid is in circular orbit around an oblate primary with axial tilt. This system is also orbiting the Sun. Thus, there are two perturbations on the secondarys orbit: J2 and third body Sun perturbations. The Laplace surface is defined as the group of orbits that lie on the Laplace plane at varying distances from the primary. If the secondary is very close to the primary, the inclination of the Laplace plane will be near the equator of the asteroid, while further from the primary the inclination will be similar to the asteroid-Sun plane. The secondary will lie on the Laplace plane because near the asteroid the Laplace plane is stable to large deviations in motion, causing the asteroid to come to rest in this orbit. Assuming the secondary is asymmetrical in shape and the bodys rotation is synchronous with its orbit, the secondary will experience the BYORP effect. BYORP can cause secular motion such as the semi-major axis of the secondary expanding or contracting. Assuming the secondary expands due to BYORP, the secondary will eventually reach the unstable region of the Laplace plane. The unstable region exists if the primary has an obliquity of 68.875 degrees or greater. The unstable region exists at 0.9 Laplace radius to 1.25 Laplace radius, where the Laplace radius is defined as the distance from the central body where the inclination of the Laplace plane orbit is half the obliquity. In the unstable region, the eccentricity of the orbit

  15. Relativistic Binaries in Globular Clusters

    Directory of Open Access Journals (Sweden)

    Matthew J. Benacquista

    2013-03-01

    Full Text Available Galactic globular clusters are old, dense star systems typically containing 10^4 – 10^6 stars. As an old population of stars, globular clusters contain many collapsed and degenerate objects. As a dense population of stars, globular clusters are the scene of many interesting close dynamical interactions between stars. These dynamical interactions can alter the evolution of individual stars and can produce tight binary systems containing one or two compact objects. In this review, we discuss theoretical models of globular cluster evolution and binary evolution, techniques for simulating this evolution that leads to relativistic binaries, and current and possible future observational evidence for this population. Our discussion of globular cluster evolution will focus on the processes that boost the production of tight binary systems and the subsequent interaction of these binaries that can alter the properties of both bodies and can lead to exotic objects. Direct N-body integrations and Fokker–Planck simulations of the evolution of globular clusters that incorporate tidal interactions and lead to predictions of relativistic binary populations are also discussed. We discuss the current observational evidence for cataclysmic variables, millisecond pulsars, and low-mass X-ray binaries as well as possible future detection of relativistic binaries with gravitational radiation.

  16. Spectral properties of binary asteroids

    Science.gov (United States)

    Pajuelo, Myriam; Birlan, Mirel; Carry, Benoît; DeMeo, Francesca E.; Binzel, Richard P.; Berthier, Jérôme

    2018-04-01

    We present the first attempt to characterize the distribution of taxonomic class among the population of binary asteroids (15% of all small asteroids). For that, an analysis of 0.8-2.5{μ m} near-infrared spectra obtained with the SpeX instrument on the NASA/IRTF is presented. Taxonomic class and meteorite analog is determined for each target, increasing the sample of binary asteroids with known taxonomy by 21%. Most binary systems are bound in the S-, X-, and C- classes, followed by Q and V-types. The rate of binary systems in each taxonomic class agrees within uncertainty with the background population of small near-Earth objects and inner main belt asteroids, but for the C-types which are under-represented among binaries.

  17. Planets in Binary Star Systems

    CERN Document Server

    Haghighipour, Nader

    2010-01-01

    The discovery of extrasolar planets over the past decade has had major impacts on our understanding of the formation and dynamical evolution of planetary systems. There are features and characteristics unseen in our solar system and unexplainable by the current theories of planet formation and dynamics. Among these new surprises is the discovery of planets in binary and multiple-star systems. The discovery of such "binary-planetary" systems has confronted astrodynamicists with many new challenges, and has led them to re-examine the theories of planet formation and dynamics. Among these challenges are: How are planets formed in binary star systems? What would be the notion of habitability in such systems? Under what conditions can binary star systems have habitable planets? How will volatiles necessary for life appear on such planets? This volume seeks to gather the current research in the area of planets in binary and multistar systems and to familiarize readers with its associated theoretical and observation...

  18. BINARY ASTROMETRIC MICROLENSING WITH GAIA

    Energy Technology Data Exchange (ETDEWEB)

    Sajadian, Sedighe, E-mail: sajadian@ipm.ir [School of Astronomy, Institute for Research in Fundamental Sciences (IPM), P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); Department of Physics, Sharif University of Technology, P.O. Box 11155-9161, Tehran (Iran, Islamic Republic of)

    2015-04-15

    We investigate whether or not Gaia can specify the binary fractions of massive stellar populations in the Galactic disk through astrometric microlensing. Furthermore, we study whether or not some information about their mass distributions can be inferred via this method. In this regard, we simulate the binary astrometric microlensing events due to massive stellar populations according to the Gaia observing strategy by considering (i) stellar-mass black holes, (ii) neutron stars, (iii) white dwarfs, and (iv) main-sequence stars as microlenses. The Gaia efficiency for detecting the binary signatures in binary astrometric microlensing events is ∼10%–20%. By calculating the optical depth due to the mentioned stellar populations, the numbers of the binary astrometric microlensing events being observed with Gaia with detectable binary signatures, for the binary fraction of about 0.1, are estimated to be 6, 11, 77, and 1316, respectively. Consequently, Gaia can potentially specify the binary fractions of these massive stellar populations. However, the binary fraction of black holes measured with this method has a large uncertainty owing to a low number of the estimated events. Knowing the binary fractions in massive stellar populations helps with studying the gravitational waves. Moreover, we investigate the number of massive microlenses for which Gaia specifies masses through astrometric microlensing of single lenses toward the Galactic bulge. The resulting efficiencies of measuring the mass of mentioned populations are 9.8%, 2.9%, 1.2%, and 0.8%, respectively. The numbers of their astrometric microlensing events being observed in the Gaia era in which the lens mass can be inferred with the relative error less than 0.5 toward the Galactic bulge are estimated as 45, 34, 76, and 786, respectively. Hence, Gaia potentially gives us some information about the mass distribution of these massive stellar populations.

  19. Content identification: binary content fingerprinting versus binary content encoding

    Science.gov (United States)

    Ferdowsi, Sohrab; Voloshynovskiy, Svyatoslav; Kostadinov, Dimche

    2014-02-01

    In this work, we address the problem of content identification. We consider content identification as a special case of multiclass classification. The conventional approach towards identification is based on content fingerprinting where a short binary content description known as a fingerprint is extracted from the content. We propose an alternative solution based on elements of machine learning theory and digital communications. Similar to binary content fingerprinting, binary content representation is generated based on a set of trained binary classifiers. We consider several training/encoding strategies and demonstrate that the proposed system can achieve the upper theoretical performance limits of content identification. The experimental results were carried out both on a synthetic dataset with different parameters and the FAMOS dataset of microstructures from consumer packages.

  20. Optimally cloned binary coherent states

    Science.gov (United States)

    Müller, C. R.; Leuchs, G.; Marquardt, Ch.; Andersen, U. L.

    2017-10-01

    Binary coherent state alphabets can be represented in a two-dimensional Hilbert space. We capitalize this formal connection between the otherwise distinct domains of qubits and continuous variable states to map binary phase-shift keyed coherent states onto the Bloch sphere and to derive their quantum-optimal clones. We analyze the Wigner function and the cumulants of the clones, and we conclude that optimal cloning of binary coherent states requires a nonlinearity above second order. We propose several practical and near-optimal cloning schemes and compare their cloning fidelity to the optimal cloner.

  1. Binary typing of staphylococcus aureus

    NARCIS (Netherlands)

    W.B. van Leeuwen (Willem)

    2002-01-01

    textabstractThis thesis describes the development. application and validation of straindifferentiating DNA probes for the characterization of Staphylococcus aureus strains in a system. that yields a binary output. By comparing the differential hybridization of these DNA probes to staphylococcal

  2. Mesoscopic model for binary fluids

    Science.gov (United States)

    Echeverria, C.; Tucci, K.; Alvarez-Llamoza, O.; Orozco-Guillén, E. E.; Morales, M.; Cosenza, M. G.

    2017-10-01

    We propose a model for studying binary fluids based on the mesoscopic molecular simulation technique known as multiparticle collision, where the space and state variables are continuous, and time is discrete. We include a repulsion rule to simulate segregation processes that does not require calculation of the interaction forces between particles, so binary fluids can be described on a mesoscopic scale. The model is conceptually simple and computationally efficient; it maintains Galilean invariance and conserves the mass and energy in the system at the micro- and macro-scale, whereas momentum is conserved globally. For a wide range of temperatures and densities, the model yields results in good agreement with the known properties of binary fluids, such as the density profile, interface width, phase separation, and phase growth. We also apply the model to the study of binary fluids in crowded environments with consistent results.

  3. Biclustering sparse binary genomic data.

    Science.gov (United States)

    van Uitert, Miranda; Meuleman, Wouter; Wessels, Lodewyk

    2008-12-01

    Genomic datasets often consist of large, binary, sparse data matrices. In such a dataset, one is often interested in finding contiguous blocks that (mostly) contain ones. This is a biclustering problem, and while many algorithms have been proposed to deal with gene expression data, only two algorithms have been proposed that specifically deal with binary matrices. None of the gene expression biclustering algorithms can handle the large number of zeros in sparse binary matrices. The two proposed binary algorithms failed to produce meaningful results. In this article, we present a new algorithm that is able to extract biclusters from sparse, binary datasets. A powerful feature is that biclusters with different numbers of rows and columns can be detected, varying from many rows to few columns and few rows to many columns. It allows the user to guide the search towards biclusters of specific dimensions. When applying our algorithm to an input matrix derived from TRANSFAC, we find transcription factors with distinctly dissimilar binding motifs, but a clear set of common targets that are significantly enriched for GO categories.

  4. Electrodeposition of Pd based binary catalysts on Carbon paper via surface limited redox-replacement reaction for oxygen reduction reaction

    CSIR Research Space (South Africa)

    Modibedi, RM

    2014-05-01

    Full Text Available attention as it is more abundant and also cheaper than Pt. In this presentation, Electrochemical Atomic Layer Deposition (ECALD) was used in the preparation of binary ORR catalysts. The binary nanoclusters were synthesised via surface-limited redox-replacement...

  5. The Young Visual Binary Survey

    Science.gov (United States)

    Prato, Lisa; Avilez, Ian; Lindstrom, Kyle; Graham, Sean; Sullivan, Kendall; Biddle, Lauren; Skiff, Brian; Nofi, Larissa; Schaefer, Gail; Simon, Michal

    2018-01-01

    Differences in the stellar and circumstellar properties of the components of young binaries provide key information about star and disk formation and evolution processes. Because objects with separations of a few to a few hundred astronomical units share a common environment and composition, multiple systems allow us to control for some of the factors which play into star formation. We are completing analysis of a rich sample of about 100 pre-main sequence binaries and higher order multiples, primarily located in the Taurus and Ophiuchus star forming regions. This poster will highlight some of out recent, exciting results. All reduced spectra and the results of our analysis will be publicly available to the community at http://jumar.lowell.edu/BinaryStars/. Support for this research was provided in part by NSF award AST-1313399 and by NASA Keck KPDA funding.

  6. Protocols for quantum binary voting

    Science.gov (United States)

    Thapliyal, Kishore; Sharma, Rishi Dutt; Pathak, Anirban

    Two new protocols for quantum binary voting are proposed. One of the proposed protocols is designed using a standard scheme for controlled deterministic secure quantum communication (CDSQC), and the other one is designed using the idea of quantum cryptographic switch, which uses a technique known as permutation of particles. A few possible alternative approaches to accomplish the same task (quantum binary voting) have also been discussed. Security of the proposed protocols is analyzed. Further, the efficiencies of the proposed protocols are computed, and are compared with that of the existing protocols. The comparison has established that the proposed protocols are more efficient than the existing protocols.

  7. Matter in compact binary mergers

    Science.gov (United States)

    Read, Jocelyn; LIGO Scientific Collaboration, Virgo Scientific Collaboration

    2018-01-01

    Mergers of binary neutron stars or neutron-star/black-hole systems are promising targets for gravitational-wave detection. The dynamics of merging compact objects, and thus their gravitational-wave signatures, are primarily determined by the mass and spin of the components. However, the presence of matter can make an imprint on the final orbits and merger of a binary system. I will outline efforts to understand the impact of neutron-star matter on gravitational waves, using both theoretical and computational input, so that gravitational-wave observations can be used to measure the properties of source systems with neutron-star components.

  8. Mental Effort in Binary Categorization Aided by Binary Cues

    Science.gov (United States)

    Botzer, Assaf; Meyer, Joachim; Parmet, Yisrael

    2013-01-01

    Binary cueing systems assist in many tasks, often alerting people about potential hazards (such as alarms and alerts). We investigate whether cues, besides possibly improving decision accuracy, also affect the effort users invest in tasks and whether the required effort in tasks affects the responses to cues. We developed a novel experimental tool…

  9. Rheology of ABS and binary of organo clay nanocomposites

    International Nuclear Information System (INIS)

    Galvan, Danieli; Mazzucco, Mateus; Carneiro, Fabio; Bartoli, Julio R.; Morales, Ana Rita; D'Avila, Marcos A.

    2011-01-01

    nanocomposites of poly(acrylonitrile-butadiene-styrene) and organically modified montmorillonite clays by melt intercalation on a co-rotating twin-screw extruder were prepared and characterized. It was studied the effects of screw torque and a binary mixture of organically modified montmorillonites on the intercalation/exfoliation of organoclays in the polymer matrix, characterized by X-ray diffraction morphological analyses and by capillary and parallel plates rheological analyses. (author)

  10. Evaluation of Griseofulvin Binary and Ternary Solid Dispersions with HPMCAS

    OpenAIRE

    Al-Obaidi, Hisham; Buckton, Graham

    2009-01-01

    The stability and dissolution properties of griseofulvin binary and ternary solid dispersions were evaluated. Solid dispersions of griseofulvin and hydroxypropyl methylcellulose acetate succinate (HPMCAS) were prepared using the spray drying method. A third polymer, poly[N-(2-hydroxypropyl)methacrylate] (PHPMA), was incorporated to investigate its effect on the interaction of griseofulvin with HPMCAS. In this case, HPMCAS can form H bonds with griseofulvin directly; the addition of PHPMA to t...

  11. Double stars with wide separations in the AGK3 - I. Components that are themselves spectroscopic binaries

    OpenAIRE

    Halbwachs, J.-L; Mayor, M.; Udry, S.

    2017-01-01

    Wide binaries are tracers of the gravity field of the Galaxy, but their study requires some caution. A large list of common proper motion stars selected from the third Astronomischen Gesellschaft Katalog (AGK3) was monitored with the CORAVEL (for COrrelation RAdial VELocities) spectrovelocimeter, in order to prepare a sample of physical binaries with very wide separations. 66 stars received special attention, since their radial velocities (RV) seemed to be variable. These stars were monitored...

  12. The Uses of Binary Thinking.

    Science.gov (United States)

    Elbow, Peter

    1993-01-01

    Argues that oppositional thinking, if handled in the right way, will serve as a way to avoid the very problems that Jonathan Culler and Paul de Mann are troubled by: "purity, order, and hierarchy." Asserts that binary thinking can serve to encourage difference--indeed, encourage nondominance, nontranscendence, instability, and disorder.…

  13. Biclustering Sparse Binary Genomic Data

    NARCIS (Netherlands)

    Van Uitert, M.; Meuleman, W.; Wessels, L.F.A.

    2008-01-01

    Genomic datasets often consist of large, binary, sparse data matrices. In such a dataset, one is often interested in finding contiguous blocks that (mostly) contain ones. This is a biclustering problem, and while many algorithms have been proposed to deal with gene expression data, only two

  14. Misclassification in binary choice models

    Czech Academy of Sciences Publication Activity Database

    Meyer, B. D.; Mittag, Nikolas

    2017-01-01

    Roč. 200, č. 2 (2017), s. 295-311 ISSN 0304-4076 R&D Projects: GA ČR(CZ) GJ16-07603Y Institutional support: Progres-Q24 Keywords : measurement error * binary choice models * program take-up Subject RIV: AH - Economics OBOR OECD: Economic Theory Impact factor: 1.633, year: 2016

  15. Misclassification in binary choice models

    Czech Academy of Sciences Publication Activity Database

    Meyer, B. D.; Mittag, Nikolas

    2017-01-01

    Roč. 200, č. 2 (2017), s. 295-311 ISSN 0304-4076 Institutional support: RVO:67985998 Keywords : measurement error * binary choice models * program take-up Subject RIV: AH - Economics OBOR OECD: Economic Theory Impact factor: 1.633, year: 2016

  16. Generating Constant Weight Binary Codes

    Science.gov (United States)

    Knight, D.G.

    2008-01-01

    The determination of bounds for A(n, d, w), the maximum possible number of binary vectors of length n, weight w, and pairwise Hamming distance no less than d, is a classic problem in coding theory. Such sets of vectors have many applications. A description is given of how the problem can be used in a first-year undergraduate computational…

  17. BHMcalc: Binary Habitability Mechanism Calculator

    Science.gov (United States)

    Zuluaga, Jorge I.; Mason, Paul; Cuartas-Restrepo, Pablo A.; Clark, Joni

    2018-02-01

    BHMcalc provides renditions of the instantaneous circumbinary habital zone (CHZ) and also calculates BHM properties of the system including those related to the rotational evolution of the stellar components and the combined XUV and SW fluxes as measured at different distances from the binary. Moreover, it provides numerical results that can be further manipulated and used to calculate other properties.

  18. Subluminous X-ray binaries

    NARCIS (Netherlands)

    Armas Padilla, M.

    2013-01-01

    The discovery of the first X-ray binary, Scorpius X-1, by Giacconi et al. (1962), marked the birth of X-ray astronomy. Following that discovery, many additional X-ray sources where found with the first generation of X-ray rockets and observatories (e.g., UHURU and Einstein). The short-timescale

  19. The Meritfactor of Binary Seqences

    DEFF Research Database (Denmark)

    Høholdt, Tom

    1999-01-01

    Binary sequences with small aperiodic correlations play an important role in many applications ranging from radar to modulation and testing of systems. Golay(1977) introduced the merit factor as a measure of the goodness of the sequence and conjectured an upper bound for this. His conjecture...

  20. Interactions in Massive Colliding Wind Binaries

    Directory of Open Access Journals (Sweden)

    Michael F. Corcoran

    2012-03-01

    Full Text Available There are observational difficulties determining dynamical masses of binary star components in the upper HR diagram both due to the scarcity of massive binary systems and spectral and photometric contamination produced by the strong wind outflows in these systems. We discuss how variable X-ray emission in these systems produced by wind-wind collisions in massive binaries can be used to constrain the system parameters, with application to two important massive binaries, Eta Carinae and WR 140.

  1. Division Unit for Binary Integer Decimals

    DEFF Research Database (Denmark)

    Lang, Tomas; Nannarelli, Alberto

    2009-01-01

    In this work, we present a radix-10 division unit that is based on the digit-recurrence algorithm and implements binary encodings (binary integer decimal or BID) for significands. Recent decimal division designs are all based on the binary coded decimal (BCD) encoding. We adapt the radix-10 digit...

  2. Permutation Entropy for Random Binary Sequences

    Directory of Open Access Journals (Sweden)

    Lingfeng Liu

    2015-12-01

    Full Text Available In this paper, we generalize the permutation entropy (PE measure to binary sequences, which is based on Shannon’s entropy, and theoretically analyze this measure for random binary sequences. We deduce the theoretical value of PE for random binary sequences, which can be used to measure the randomness of binary sequences. We also reveal the relationship between this PE measure with other randomness measures, such as Shannon’s entropy and Lempel–Ziv complexity. The results show that PE is consistent with these two measures. Furthermore, we use PE as one of the randomness measures to evaluate the randomness of chaotic binary sequences.

  3. Gravity waves from relativistic binaries

    OpenAIRE

    Levin, Janna; O'Reilly, Rachel; Copeland, E. J.

    1999-01-01

    The stability of binary orbits can significantly shape the gravity wave signal which future Earth-based interferometers hope to detect. The inner most stable circular orbit has been of interest as it marks the transition from the late inspiral to final plunge. We consider purely relativistic orbits beyond the circular assumption. Homoclinic orbits are of particular importance to the question of stability as they lie on the boundary between dynamical stability and instability. We identify thes...

  4. Tenoxicam-kollicoat IR binary systems: physicochemical and biological evaluation.

    Science.gov (United States)

    Ibrahim, Mohamed Abbas

    2014-01-01

    Tenoxicam (TNX) binary systems in Kollicoat IR (KL) matrix were prepared in different drug: polymer ratios using kneading and spray-drying method. The prepared binary systems were characterized for drug dissolution rate, differential scanning calorimetry (DSC), IR spectroscopy and x-ray diffractometry. The results showed that the drug dissolution rate was remarkably enhanced by incorporating it in the KL matrix either by kneading or spray-drying, and the dissolution rate was increased by decreasing the drug weight ratio. The DSc and x-ray studies revealed the presence of TNX in less crystalline or amorphous state in its-KL binary systems. Moreover, the spray-dried TNX-KL system in 1:4 ratio, that exhibited the faster dissolution rate, was formulated in oral disintegrating tablets (ODTs). The data indicated that a fast disintegration and higher drug dissolution rate was achieved in case of the ODTs containing the spray-dried form compared to the ODTS containing untreated drug or the commercial tablet (Epicotil). Also, the drug exhibited significantly (p < 0.01) faster onset of the anti-inflammatory analgesic activities in case of the ODTs containing the spray-dried form, that was superior to that observed with both the commercial tablet product and the ODTS containing untreated drug.

  5. Binary evolution and observational constraints

    International Nuclear Information System (INIS)

    Loore, C. de

    1984-01-01

    The evolution of close binaries is discussed in connection with problems concerning mass and angular momentum losses. Theoretical and observational evidence for outflow of matter, leaving the system during evolution is given: statistics on total masses and mass ratios, effects of the accretion of the mass gaining component, the presence of streams, disks, rings, circumstellar envelopes, period changes, abundance changes in the atmosphere. The effects of outflowing matter on the evolution is outlined, and estimates of the fraction of matter expelled by the loser, and leaving the system, are given. The various time scales involved with evolution and observation are compared. Examples of non conservative evolution are discussed. Problems related to contact phases, on mass and energy losses, in connection with entropy changes are briefly analysed. For advanced stages the disruption probabilities for supernova explosions are examined. A global picture is given for the evolution of massive close binaries, from ZAMS, through WR phases, X-ray phases, leading to runaway pulsars or to a binary pulsar and later to a millisecond pulsar. (Auth.)

  6. Binary phosphates NaLnP2O7

    International Nuclear Information System (INIS)

    Anisimova, N.Yu.; Trunov, V.K.; Chudinova, N.N.

    1988-01-01

    The results of synthesis and identification of compounds of the NaLnP 2 O 7 (Ln=La,...Lu) composition are presented. 14 compounds of the above composition referring to two structural types are prepared and characterized. The data on NaLnP 2 O 7 synthesis in the Na 2 O-Ln:2O 3 -P 2 O 5 system are given. Binary phosphates of the NaLnP 2 O 7 -type (Ln=La,...Lu) are separated and identified in the subsolidus part of the Na 2 O-Ln 2 O 3 -P 2 O 5 system. Their crystallochemical parameters are determined and the presence of two structural types in the La-Lu series is shown. Thermal stability of binary phosphates is studied

  7. Quantum memory receiver for superadditive communication using binary coherent states.

    Science.gov (United States)

    Klimek, Aleksandra; Jachura, Michał; Wasilewski, Wojciech; Banaszek, Konrad

    2016-11-12

    We propose a simple architecture based on multimode quantum memories for collective readout of classical information keyed using a pair coherent states, exemplified by the well-known binary phase shift keying format. Such a configuration enables demonstration of the superadditivity effect in classical communication over quantum channels, where the transmission rate becomes enhanced through joint detection applied to multiple channel uses. The proposed scheme relies on the recently introduced idea to prepare Hadamard sequences of input symbols that are mapped by a linear optical transformation onto the pulse position modulation format [Guha, S. Phys. Rev. Lett. 2011 , 106 , 240502]. We analyze two versions of readout based on direct detection and an optional Dolinar receiver which implements the minimum-error measurement for individual detection of a binary coherent state alphabet.

  8. Effect of preparation temperature and ions doping on size ...

    African Journals Online (AJOL)

    Binary and quaternary amorphous nano powders are prepared by wet reduction method. Cobalt boride nano catalyst is synthesized at 10 and 60 ºC. Effect of preparation temperature on size and morphology was studied. Co-M-Zr-B (M: Cr, Mo and W) as quaternary catalysts are also prepared in order to studying ions ...

  9. Binary Effect of Fly Ash and Palm Oil Fuel Ash on Heat of Hydration Aerated Concrete

    Science.gov (United States)

    Mehmannavaz, Taha; Ismail, Mohammad; Radin Sumadi, Salihuddin; Rafique Bhutta, Muhammad Aamer; Samadi, Mostafa

    2014-01-01

    The binary effect of pulverized fuel ash (PFA) and palm oil fuel ash (POFA) on heat of hydration of aerated concrete was studied. Three aerated concrete mixes were prepared, namely, concrete containing 100% ordinary Portland cement (control sample or Type I), binary concrete made from 50% POFA (Type II), and ternary concrete containing 30% POFA and 20% PFA (Type III). It is found that the temperature increases due to heat of hydration through all the concrete specimens especially in the control sample. However, the total temperature rises caused by the heat of hydration through both of the new binary and ternary concrete were significantly lower than the control sample. The obtained results reveal that the replacement of Portland cement with binary and ternary materials is beneficial, particularly for mass concrete where thermal cracking due to extreme heat rise is of great concern. PMID:24696646

  10. The structures of binary compounds

    CERN Document Server

    Hafner, J; Jensen, WB; Majewski, JA; Mathis, K; Villars, P; Vogl, P; de Boer, FR

    1990-01-01

    - Up-to-date compilation of the experimental data on the structures of binary compounds by Villars and colleagues. - Coloured structure maps which order the compounds into their respective structural domains and present for the first time the local co-ordination polyhedra for the 150 most frequently occurring structure types, pedagogically very helpful and useful in the search for new materials with a required crystal structure. - Crystal co-ordination formulas: a flexible notation for the interpretation of solid-state structures by chemist Bill Jensen. - Recent important advances in unders

  11. Young and Waltzing Binary Stars

    Science.gov (United States)

    2001-10-01

    ADONIS Observes Low-mass Eclipsing System in Orion Summary A series of very detailed images of a binary system of two young stars have been combined into a movie . In merely 3 days, the stars swing around each other. As seen from the earth, they pass in front of each other twice during a full revolution, producing eclipses during which their combined brightness diminishes . A careful analysis of the orbital motions has now made it possible to deduce the masses of the two dancing stars . Both turn out to be about as heavy as our Sun. But while the Sun is about 4500 million years old, these two stars are still in their infancy. They are located some 1500 light-years away in the Orion star-forming region and they probably formed just 10 million years ago . This is the first time such an accurate determination of the stellar masses could be achieved for a young binary system of low-mass stars . The new result provides an important piece of information for our current understanding of how young stars evolve. The observations were obtained by a team of astronomers from Italy and ESO [1] using the ADaptive Optics Near Infrared System (ADONIS) on the 3.6-m telescope at the ESO La Silla Observatory. PR Photo 29a/01 : The RXJ 0529.4+0041 system before primary eclipse PR Photo 29b/01 : The RXJ 0529.4+0041 system at mid-primary eclipse PR Photo 29c/01 : The RXJ 0529.4+0041 system after primary eclipse PR Photo 29d/01 : The RXJ 0529.4+0041 system before secondary eclipse PR Photo 29e/01 : The RXJ 0529.4+0041 system at mid-secondary eclipse PR Photo 29f/01 : The RXJ 0529.4+0041 system after secondary eclipse PR Video Clip 06/01 : Video of the RXJ 0529.4+0041 system Binary stars and stellar masses Since some time, astronomers have noted that most stars seem to form in binary or multiple systems. This is quite fortunate, as the study of binary stars is the only way in which it is possible to measure directly one of the most fundamental quantities of a star, its mass. The mass of a

  12. Pulsar magnetospheres in binary systems

    Science.gov (United States)

    Ershkovich, A. I.; Dolan, J. F.

    1985-01-01

    The criterion for stability of a tangential discontinuity interface in a magnetized, perfectly conducting inviscid plasma is investigated by deriving the dispersion equation including the effects of both gravitational and centrifugal acceleration. The results are applied to neutron star magnetospheres in X-ray binaries. The Kelvin-Helmholtz instability appears to be important in determining whether MHD waves of large amplitude generated by instability may intermix the plasma effectively, resulting in accretion onto the whole star as suggested by Arons and Lea and leading to no X-ray pulsar behavior.

  13. Tomographic reconstruction of binary fields

    International Nuclear Information System (INIS)

    Roux, Stéphane; Leclerc, Hugo; Hild, François

    2012-01-01

    A novel algorithm is proposed for reconstructing binary images from their projection along a set of different orientations. Based on a nonlinear transformation of the projection data, classical back-projection procedures can be used iteratively to converge to the sought image. A multiscale implementation allows for a faster convergence. The algorithm is tested on images up to 1 Mb definition, and an error free reconstruction is achieved with a very limited number of projection data, saving a factor of about 100 on the number of projections required for classical reconstruction algorithms.

  14. Microlensing Signature of Binary Black Holes

    Science.gov (United States)

    Schnittman, Jeremy; Sahu, Kailash; Littenberg, Tyson

    2012-01-01

    We calculate the light curves of galactic bulge stars magnified via microlensing by stellar-mass binary black holes along the line-of-sight. We show the sensitivity to measuring various lens parameters for a range of survey cadences and photometric precision. Using public data from the OGLE collaboration, we identify two candidates for massive binary systems, and discuss implications for theories of star formation and binary evolution.

  15. Survival of planets around shrinking stellar binaries

    Science.gov (United States)

    Muñoz, Diego J.; Lai, Dong

    2015-01-01

    The discovery of transiting circumbinary planets by the Kepler mission suggests that planets can form efficiently around binary stars. None of the stellar binaries currently known to host planets has a period shorter than 7 d, despite the large number of eclipsing binaries found in the Kepler target list with periods shorter than a few days. These compact binaries are believed to have evolved from wider orbits into their current configurations via the so-called Lidov–Kozai migration mechanism, in which gravitational perturbations from a distant tertiary companion induce large-amplitude eccentricity oscillations in the binary, followed by orbital decay and circularization due to tidal dissipation in the stars. Here we explore the orbital evolution of planets around binaries undergoing orbital decay by this mechanism. We show that planets may survive and become misaligned from their host binary, or may develop erratic behavior in eccentricity, resulting in their consumption by the stars or ejection from the system as the binary decays. Our results suggest that circumbinary planets around compact binaries could still exist, and we offer predictions as to what their orbital configurations should be like. PMID:26159412

  16. Speech perception of noise with binary gains

    DEFF Research Database (Denmark)

    Wang, DeLiang; Kjems, Ulrik; Pedersen, Michael Syskind

    2008-01-01

    For a given mixture of speech and noise, an ideal binary time-frequency mask is constructed by comparing speech energy and noise energy within local time-frequency units. It is observed that listeners achieve nearly perfect speech recognition from gated noise with binary gains prescribed...... by the ideal binary mask. Only 16 filter channels and a frame rate of 100 Hz are sufficient for high intelligibility. The results show that, despite a dramatic reduction of speech information, a pattern of binary gains provides an adequate basis for speech perception....

  17. Survival of planets around shrinking stellar binaries.

    Science.gov (United States)

    Muñoz, Diego J; Lai, Dong

    2015-07-28

    The discovery of transiting circumbinary planets by the Kepler mission suggests that planets can form efficiently around binary stars. None of the stellar binaries currently known to host planets has a period shorter than 7 d, despite the large number of eclipsing binaries found in the Kepler target list with periods shorter than a few days. These compact binaries are believed to have evolved from wider orbits into their current configurations via the so-called Lidov-Kozai migration mechanism, in which gravitational perturbations from a distant tertiary companion induce large-amplitude eccentricity oscillations in the binary, followed by orbital decay and circularization due to tidal dissipation in the stars. Here we explore the orbital evolution of planets around binaries undergoing orbital decay by this mechanism. We show that planets may survive and become misaligned from their host binary, or may develop erratic behavior in eccentricity, resulting in their consumption by the stars or ejection from the system as the binary decays. Our results suggest that circumbinary planets around compact binaries could still exist, and we offer predictions as to what their orbital configurations should be like.

  18. Plutonium microstructures. Part 2. Binary and ternary alloys

    International Nuclear Information System (INIS)

    Cramer, E.M.; Bergin, J.B.

    1983-12-01

    This report is the second of three parts that exhibit illustrations of inclusions in plutonium metal from inherent and tramp impurities, of intermetallic and nonmetallic constituents from alloy additions, and of the effects of thermal and mechanical treatments. This part includes illustrations of the microstructures in binary cast alloys and a few selected ternary alloys that result from measured additions of diluent elements, and of the microconstituents that are characteristic of phase fields in extended alloy systems. Microhardness data are given and the etchant used in the preparation of each sample is described

  19. Method of all-optical frequency encoded decimal to binary and binary coded decimal, binary to gray, and gray to binary data conversion using semiconductor optical amplifiers.

    Science.gov (United States)

    Garai, Sisir Kumar

    2011-07-20

    Conversion of optical data from decimal to binary format is very important in optical computing and optical signal processing. There are many binary code systems to represent decimal numbers, the most common being the binary coded decimal (BCD) and gray code system. There are a wide choice of BCD codes, one of which is a natural BCD having a weighted code of 8421, by means of which it is possible to represent a decimal number from 0 to 9 with a combination of 4 bit binary digits. The reflected binary code, also known as the Gray code, is a binary numeral system where two successive values differ in only 1 bit. The Gray code is very important in digital optical communication as it is used to prevent spurious output from optical switches as well as to facilitate error correction in digital communications in an optical domain. Here in this communication, the author proposes an all-optical frequency encoded method of ":decimal to binary, BCD," "binary to gray," and "gray to binary" data conversion using the high-speed switching actions of semiconductor optical amplifiers. To convert decimal numbers to a binary form, a frequency encoding technique is adopted to represent two binary bits, 0 and 1. The frequency encoding technique offers advantages over conventional encoding techniques in terms of less probability of bit errors and greater reliability. Here the author has exploited the polarization switch made of a semiconductor optical amplifier (SOA) and a property of nonlinear rotation of the state of polarization of the probe beam in SOA for frequency conversion to develop the method of frequency encoded data conversion. © 2011 Optical Society of America

  20. Evaluation of griseofulvin binary and ternary solid dispersions with HPMCAS.

    Science.gov (United States)

    Al-Obaidi, Hisham; Buckton, Graham

    2009-01-01

    The stability and dissolution properties of griseofulvin binary and ternary solid dispersions were evaluated. Solid dispersions of griseofulvin and hydroxypropyl methylcellulose acetate succinate (HPMCAS) were prepared using the spray drying method. A third polymer, poly[N-(2-hydroxypropyl)methacrylate] (PHPMA), was incorporated to investigate its effect on the interaction of griseofulvin with HPMCAS. In this case, HPMCAS can form H bonds with griseofulvin directly; the addition of PHPMA to the solid dispersion may enhance the stability of the amorphous griseofulvin due to greater interaction with griseofulvin. The X-ray powder diffraction results showed that griseofulvin (binary and ternary solid dispersions) remained amorphous for more than 19 months stored at 85% RH compared with the spray-dried griseofulvin which crystallized totally within 24 h at ambient conditions. The Fourier transform infrared scan showed that griseofulvin carbonyl group formed hydrogen bonds with the hydroxyl group in the HPMCAS, which could explain the extended stability of the drug. Further broadening in the peak could be seen when PHPMA was added to the solid dispersion, which indicates stronger interaction. The glass transition temperatures increased in the ternary solid dispersions regardless of HPMCAS grade. The dissolution rate of the drug in the solid dispersion (both binary and ternary) has significantly increased when compared with the dissolution profile of the spray-dried griseofulvin. These results reveal significant stability of the amorphous form due to the hydrogen bond formation with the polymer. The addition of the third polymer improved the stability but had a minor impact on dissolution.

  1. Binary Relations as a Foundation of Mathematics

    NARCIS (Netherlands)

    Kuper, Jan; Barendsen, E.; Capretta, V.; Geuvers, H.; Niqui, M.

    2007-01-01

    We describe a theory for binary relations in the Zermelo-Fraenkel style. We choose for ZFCU, a variant of ZFC Set theory in which the Axiom of Foundation is replaced by an axiom allowing for non-wellfounded sets. The theory of binary relations is shown to be equi-consistent ZFCU by constructing a

  2. Novel quantum inspired binary neural network algorithm

    Indian Academy of Sciences (India)

    In this paper, a quantum based binary neural network algorithm is proposed, named as novel quantum binary neural network algorithm (NQ-BNN). It forms a neural network structure by deciding weights and separability parameter in quantum based manner. Quantum computing concept represents solution probabilistically ...

  3. The Evolution of Compact Binary Star Systems.

    Science.gov (United States)

    Postnov, Konstantin A; Yungelson, Lev R

    2014-01-01

    We review the formation and evolution of compact binary stars consisting of white dwarfs (WDs), neutron stars (NSs), and black holes (BHs). Mergings of compact-star binaries are expected to be the most important sources for forthcoming gravitational-wave (GW) astronomy. In the first part of the review, we discuss observational manifestations of close binaries with NS and/or BH components and their merger rate, crucial points in the formation and evolution of compact stars in binary systems, including the treatment of the natal kicks, which NSs and BHs acquire during the core collapse of massive stars and the common envelope phase of binary evolution, which are most relevant to the merging rates of NS-NS, NS-BH and BH-BH binaries. The second part of the review is devoted mainly to the formation and evolution of binary WDs and their observational manifestations, including their role as progenitors of cosmologically-important thermonuclear SN Ia. We also consider AM CVn-stars, which are thought to be the best verification binary GW sources for future low-frequency GW space interferometers.

  4. The Evolution of Compact Binary Star Systems

    Directory of Open Access Journals (Sweden)

    Yungelson, Lev R.

    2006-12-01

    Full Text Available We review the formation and evolution of compact binary stars consisting of white dwarfs (WDs, neutron stars (NSs, and black holes (BHs. Binary NSs and BHs are thought to be the primary astrophysical sources of gravitational waves (GWs within the frequency band of ground-based detectors, while compact binaries of WDs are important sources of GWs at lower frequencies to be covered by space interferometers (LISA. Major uncertainties in the current understanding of properties of NSs and BHs most relevant to the GW studies are discussed, including the treatment of the natal kicks which compact stellar remnants acquire during the core collapse of massive stars and the common envelope phase of binary evolution. We discuss the coalescence rates of binary NSs and BHs and prospects for their detections, the formation and evolution of binary WDs and their observational manifestations. Special attention is given to AM CVn-stars -- compact binaries in which the Roche lobe is filled by another WD or a low-mass partially degenerate helium-star, as these stars are thought to be the best LISA verification binary GW sources.

  5. Bondi-Hoyle-Lyttleton Accretion onto Binaries

    Science.gov (United States)

    Antoni, Andrea; MacLeod, Morgan; Ramírez-Ruiz, Enrico

    2018-01-01

    Binary stars are not rare. While only close binary stars will eventually interact with one another, even the widest binary systems interact with their gaseous surroundings. The rates of accretion and the gaseous drag forces arising in these interactions are the key to understanding how these systems evolve. This poster examines accretion flows around a binary system moving supersonically through a background gas. We perform three-dimensional hydrodynamic simulations of Bondi-Hoyle-Lyttleton accretion using the adaptive mesh refinement code FLASH. We simulate a range of values of semi-major axis of the orbit relative to the gravitational focusing impact parameter of the pair. On large scales, gas is gravitationally focused by the center-of-mass of the binary, leading to dynamical friction drag and to the accretion of mass and momentum. On smaller scales, the orbital motion imprints itself on the gas. Notably, the magnitude and direction of the forces acting on the binary inherit this orbital dependence. The long-term evolution of the binary is determined by the timescales for accretion, slow down of the center-of-mass, and decay of the orbit. We use our simulations to measure these timescales and to establish a hierarchy between them. In general, our simulations indicate that binaries moving through gaseous media will slow down before the orbit decays.

  6. The Evolution of Compact Binary Star Systems

    Directory of Open Access Journals (Sweden)

    Konstantin A. Postnov

    2014-05-01

    Full Text Available We review the formation and evolution of compact binary stars consisting of white dwarfs (WDs, neutron stars (NSs, and black holes (BHs. Mergings of compact-star binaries are expected to be the most important sources for forthcoming gravitational-wave (GW astronomy. In the first part of the review, we discuss observational manifestations of close binaries with NS and/or BH components and their merger rate, crucial points in the formation and evolution of compact stars in binary systems, including the treatment of the natal kicks, which NSs and BHs acquire during the core collapse of massive stars and the common envelope phase of binary evolution, which are most relevant to the merging rates of NS-NS, NS-BH and BH-BH binaries. The second part of the review is devoted mainly to the formation and evolution of binary WDs and their observational manifestations, including their role as progenitors of cosmologically-important thermonuclear SN Ia. We also consider AM CVn-stars, which are thought to be the best verification binary GW sources for future low-frequency GW space interferometers.

  7. Microlensing Binaries with Candidate Brown Dwarf Companions

    DEFF Research Database (Denmark)

    Shin, I.-G; Han, C.; Gould, A.

    2012-01-01

    Brown dwarfs are important objects because they may provide a missing link between stars and planets, two populations that have dramatically different formation histories. In this paper, we present the candidate binaries with brown dwarf companions that are found by analyzing binary microlensing...... with well-covered light curves increases with new-generation searches....

  8. Statistical properties of spectroscopic binary stars

    NARCIS (Netherlands)

    Hogeveen, S.J.

    1992-01-01

    As part of a study of the mass-ratio distribution of spectroscopic binary stars, the statistical properties of the systems in the Eighth Catalogue of the Orbital Elements of Spectroscopic Binary Stars, compiled by Batten et al. (1989), are investigated. Histograms are presented of the

  9. An Acidity Scale for Binary Oxides.

    Science.gov (United States)

    Smith, Derek W.

    1987-01-01

    Discusses the classification of binary oxides as acidic, basic, or amphoteric. Demonstrates how a numerical scale for acidity/basicity of binary oxides can be constructed using thermochemical data for oxoacid salts. Presents the calculations derived from the data that provide the numeric scale values. (TW)

  10. Binary trees equipped with semivaluations | Pajoohesh ...

    African Journals Online (AJOL)

    Our interest in this lattice stems from its application to binary decision trees. Binary decision trees form a crucial tool for algorithmic time analysis. The lattice properties of Tn are studied and we show that every Tn has a sublattice isomorphic to Tn-1 and prove that Tn is generated by Tn-1. Also we show that the distance from ...

  11. Eliciting Subjective Probabilities with Binary Lotteries

    DEFF Research Database (Denmark)

    Harrison, Glenn W.; Martínez-Correa, Jimmy; Swarthout, J. Todd

    objective probabilities. Drawing a sample from the same subject population, we find evidence that the binary lottery procedure induces linear utility in a subjective probability elicitation task using the Quadratic Scoring Rule. We also show that the binary lottery procedure can induce direct revelation...

  12. Logistic chaotic maps for binary numbers generations

    International Nuclear Information System (INIS)

    Kanso, Ali; Smaoui, Nejib

    2009-01-01

    Two pseudorandom binary sequence generators, based on logistic chaotic maps intended for stream cipher applications, are proposed. The first is based on a single one-dimensional logistic map which exhibits random, noise-like properties at given certain parameter values, and the second is based on a combination of two logistic maps. The encryption step proposed in both algorithms consists of a simple bitwise XOR operation of the plaintext binary sequence with the keystream binary sequence to produce the ciphertext binary sequence. A threshold function is applied to convert the floating-point iterates into binary form. Experimental results show that the produced sequences possess high linear complexity and very good statistical properties. The systems are put forward for security evaluation by the cryptographic committees.

  13. Mass Transfer in Mira-Type Binaries

    Directory of Open Access Journals (Sweden)

    Mohamed S.

    2012-06-01

    Full Text Available Detached, symbiotic binaries are generally assumed to interact via Bondi-Hoyle-Littleton (BHL wind accretion. However, the accretion rates and outflow geometries that result from this mass-transfer mechanism cannot adequately explain the observations of the nearest and best studied symbiotic binary, Mira, or the formation of some post-AGB binaries, e.g. barium stars. We propose a new mass-transfer mode for Mira-type binaries, which we call ‘wind Roche-lobe overflow’ (WRLOF, and which we demonstrate with 3D hydrodynamic simulations. Importantly, we show that the circumstellar outflows which result from WRLOF tend to be highly aspherical and strongly focused towards the binary orbital plane. Furthermore, the subsequent mass-transfer rates are at least an order of magnitude greater than the analogous BHL values. We discuss the implications of these results for the shaping of bipolar (proto-planetary nebulae and other related systems.

  14. Detection Rates for Close Binaries via Microlensing

    Science.gov (United States)

    Gaudi, B. Scott; Gould, Andrew

    1997-06-01

    Microlensing is one of the most promising methods of reconstructing the stellar mass function down to masses even below the hydrogen-burning limit. The fundamental limit to this technique is the presence of unresolved binaries, which can, in principle, significantly alter the inferred mass function. Here we quantify the fraction of binaries that can be detected using microlensing, considering specifically the mass ratio and separation of the binary. We find that almost all binary systems with separations greater than b ~ 0.4 of their combined Einstein ring radius are detectable assuming a detection threshold of 3%. For two M dwarfs, this corresponds to a limiting separation of >~1 AU. Since very few observed M dwarfs have companions at separations corrupt the measurements of the mass function. We find that the detectability depends only weakly on the mass ratio. For those events for which individual masses can be determined, we find that binaries can be detected down to b ~ 0.2.

  15. Evolution of Supermassive Black-Hole Binaries

    Science.gov (United States)

    Milosavljevic, M.; Merritt, D.

    2000-10-01

    Binary supermassive black holes are expected to form in galactic nuclei following galaxy mergers. We report large-scale N-body simulations using the Aarseth/Spurzem parallel code NBODY6++ of the formation and evolution of such binaries. Initial conditions are drawn from a tree-code simulation of the merger of two spherical galaxies with ρ ~ r-2 density cusps (Cruz & Merritt, AAS Poster). Once the two black holes form a bound pair at the center of the merged galaxies, the evolution is continued using NBODY6++ at much higher resolution. Its exact force calculations generate faithful binary dynamics until the onset of gravity wave-dominated dissipation. We discuss the binary hardening rate, the amplitude of the binary's wandering, and the evolution of the structure of the galactic stellar nucleus.

  16. Phonons in fcc binary alloys

    International Nuclear Information System (INIS)

    Sharma, Amita; Rathore, R.P.S.

    1992-01-01

    Born-Mayer potential has been modified to account for the unpaired (three body) forces among the common nearest neighbours of the ordered binary fcc alloys i.e. Ni 3 Fe 7 , Ni 5 Fe 5 and Ni 75 Fe 25 . The three body potential is added to the two body form of Morse to formalize the total interaction potential. Measured inverse ionic compressibility, cohesive energy, lattice constant and one measured phonon frequency are used to evaluate the defining parameters of the potential. The potential seeks to bring about the binding among 140 and 132 atoms though pair wise (two body) and non-pair wise (three body) forces respectively. The phonon-dispersion relations obtained by solving the secular equation are compared with the experimental findings on the aforesaid alloys. (author). 19 refs., 3 figs

  17. Mesoporous CuO–ZnO binary metal oxide nanocomposite for decontamination of sulfur mustard

    Energy Technology Data Exchange (ETDEWEB)

    Praveen Kumar, J.; Prasad, G.K., E-mail: gkprasad2001@yahoo.com; Ramacharyulu, P.V.R.K.; Garg, P.; Ganesan, K.

    2013-11-01

    Mesoporous CuO–ZnO binary metal oxide nanocomposites were studied as sorbent decontaminants against sulfur mustard, a well known chemical warfare agent. They were prepared by precipitation pyrolysis method and characterized by means of X-ray diffraction, transmission electron microscopy, nitrogen adsorption, Fourier transform infrared spectroscopy techniques. Obtained data indicated the presence of mesopores with diameter ranging from 2 to 80 nm and the materials exhibited relatively high surface area 86 m{sup 2} g{sup −1} when compared to the individual metal oxide nanoparticles. Reactive sites of mesoporous CuO–ZnO binary metal oxide nanocomposites were studied by infrared spectroscopy technique using pyridine as a probe molecule. These materials demonstrated superior decontamination properties against sulfur mustard when compared to single component metal oxides and decontaminated it to divinyl sulfide, chloroethyl vinyl sulfide, hemisulfur mustard, etc. - Graphical abstract: Mesoporous CuO–ZnO binary metal oxide nanocomposites were studied as sorbent decontaminants against sulfur mustard, a well known chemical warfare agent. These materials demonstrated superior decontamination properties against sulfur mustard and decontaminated it to divinyl sulfide, chloroethyl vinyl sulfide, hemisulfur mustard, etc. - Highlights: • Preparation of mesoporous CuO–ZnO binary metal oxide nanocomposite. • CuO–ZnO with better surface area was synthesized by precipitation pyrolysis. • Decontamination of HD using mesoporous CuO–ZnO binary metal oxide nanocomposite. • HD decontaminated by elimination and hydrolysis reactions.

  18. Mesoporous CuO–ZnO binary metal oxide nanocomposite for decontamination of sulfur mustard

    International Nuclear Information System (INIS)

    Praveen Kumar, J.; Prasad, G.K.; Ramacharyulu, P.V.R.K.; Garg, P.; Ganesan, K.

    2013-01-01

    Mesoporous CuO–ZnO binary metal oxide nanocomposites were studied as sorbent decontaminants against sulfur mustard, a well known chemical warfare agent. They were prepared by precipitation pyrolysis method and characterized by means of X-ray diffraction, transmission electron microscopy, nitrogen adsorption, Fourier transform infrared spectroscopy techniques. Obtained data indicated the presence of mesopores with diameter ranging from 2 to 80 nm and the materials exhibited relatively high surface area 86 m 2 g −1 when compared to the individual metal oxide nanoparticles. Reactive sites of mesoporous CuO–ZnO binary metal oxide nanocomposites were studied by infrared spectroscopy technique using pyridine as a probe molecule. These materials demonstrated superior decontamination properties against sulfur mustard when compared to single component metal oxides and decontaminated it to divinyl sulfide, chloroethyl vinyl sulfide, hemisulfur mustard, etc. - Graphical abstract: Mesoporous CuO–ZnO binary metal oxide nanocomposites were studied as sorbent decontaminants against sulfur mustard, a well known chemical warfare agent. These materials demonstrated superior decontamination properties against sulfur mustard and decontaminated it to divinyl sulfide, chloroethyl vinyl sulfide, hemisulfur mustard, etc. - Highlights: • Preparation of mesoporous CuO–ZnO binary metal oxide nanocomposite. • CuO–ZnO with better surface area was synthesized by precipitation pyrolysis. • Decontamination of HD using mesoporous CuO–ZnO binary metal oxide nanocomposite. • HD decontaminated by elimination and hydrolysis reactions

  19. Albendazole Microparticles Prepared by Spray Drying Technique ...

    African Journals Online (AJOL)

    Purpose: To enhance the dissolution of albendazole (ABZ) using spray-drying technique. Method: ABZ binary mixtures with Kollicoat IR® (KL) and polyvinyl pyrrolidone (PVP) in various drug to polymer ratios (1: 1, 1: 2 and 1; 4) were prepared by spray-drying. The spray-dried particles were characterized for particle shape, ...

  20. "One-sample concept" micro-combinatory for high throughput TEM of binary films.

    Science.gov (United States)

    Sáfrán, György

    2018-04-01

    Phases of thin films may remarkably differ from that of bulk. Unlike to the comprehensive data files of Binary Phase Diagrams [1] available for bulk, complete phase maps for thin binary layers do not exist. This is due to both the diverse metastable, non-equilibrium or instable phases feasible in thin films and the required volume of characterization work with analytical techniques like TEM, SAED and EDS. The aim of the present work was to develop a method that remarkably facilitates the TEM study of the diverse binary phases of thin films, or the creation of phase maps. A micro-combinatorial method was worked out that enables both preparation and study of a gradient two-component film within a single TEM specimen. For a demonstration of the technique thin Mn x Al 1- x binary samples with evolving concentration from x = 0 to x = 1 have been prepared so that the transition from pure Mn to pure Al covers a 1.5 mm long track within the 3 mm diameter TEM grid. The proposed method enables the preparation and study of thin combinatorial samples including all feasible phases as a function of composition or other deposition parameters. Contrary to known "combinatorial chemistry", in which a series of different samples are deposited in one run, and investigated, one at a time, the present micro-combinatorial method produces a single specimen condensing a complete library of a binary system that can be studied, efficiently, within a single TEM session. That provides extremely high throughput for TEM characterization of composition-dependent phases, exploration of new materials, or the construction of phase diagrams of binary films. Copyright © 2018 Elsevier B.V. All rights reserved.

  1. BPASS predictions for binary black hole mergers

    Science.gov (United States)

    Eldridge, J. J.; Stanway, E. R.

    2016-11-01

    Using the Binary Population and Spectral Synthesis code, BPASS, we have calculated the rates, time-scales and mass distributions for binary black hole (BH) mergers as a function of metallicity. We consider these in the context of the recently reported first Laser Interferometer Gravitational-Wave Observatory (LIGO) event detection. We find that the event has a very low probability of arising from a stellar population with initial metallicity mass fraction above Z = 0.010 (Z ≳ 0.5 Z⊙). Binary BH merger events with the reported masses are most likely in populations below 0.008 (Z ≲ 0.4 Z⊙). Events of this kind can occur at all stellar population ages from 3 Myr up to the age of the Universe, but constitute only 0.1-0.4 per cent of binary BH mergers between metallicities of Z = 0.001 and 0.008. However at metallicity Z = 10-4, 26 per cent of binary BH mergers would be expected to have the reported masses. At this metallicity, the progenitor merger times can be close to ≈10 Gyr and rotationally mixed stars evolving through quasi-homogeneous evolution, due to mass transfer in a binary, dominate the rate. The masses inferred for the BHs in the binary progenitor of GW 150914 are amongst the most massive expected at anything but the lowest metallicities in our models. We discuss the implications of our analysis for the electromagnetic follow-up of future LIGO event detections.

  2. Topological and categorical properties of binary trees

    Directory of Open Access Journals (Sweden)

    H. Pajoohesh

    2008-04-01

    Full Text Available Binary trees are very useful tools in computer science for estimating the running time of so-called comparison based algorithms, algorithms in which every action is ultimately based on a prior comparison between two elements. For two given algorithms A and B where the decision tree of A is more balanced than that of B, it is known that the average and worst case times of A will be better than those of B, i.e., ₸A(n ≤₸B(n and TWA (n≤TWB (n. Thus the most balanced and the most imbalanced binary trees play a main role. Here we consider them as semilattices and characterize the most balanced and the most imbalanced binary trees by topological and categorical properties. Also we define the composition of binary trees as a commutative binary operation, *, such that for binary trees A and B, A * B is the binary tree obtained by attaching a copy of B to any leaf of A. We show that (T,* is a commutative po-monoid and investigate its properties.

  3. Instabilities in Interacting Binary Stars

    Science.gov (United States)

    Andronov, I. L.; Andrych, K. D.; Antoniuk, K. A.; Baklanov, A. V.; Beringer, P.; Breus, V. V.; Burwitz, V.; Chinarova, L. L.; Chochol, D.; Cook, L. M.; Cook, M.; Dubovský, P.; Godlowski, W.; Hegedüs, T.; Hoňková, K.; Hric, L.; Jeon, Y.-B.; Juryšek, J.; Kim, C.-H.; Kim, Y.; Kim, Y.-H.; Kolesnikov, S. V.; Kudashkina, L. S.; Kusakin, A. V.; Marsakova, V. I.; Mason, P. A.; Mašek, M.; Mishevskiy, N.; Nelson, R. H.; Oksanen, A.; Parimucha, S.; Park, J.-W.; Petrík, K.; Quiñones, C.; Reinsch, K.; Robertson, J. W.; Sergey, I. M.; Szpanko, M.; Tkachenko, M. G.; Tkachuk, L. G.; Traulsen, I.; Tremko, J.; Tsehmeystrenko, V. S.; Yoon, J.-N.; Zola, S.; Shakhovskoy, N. M.

    2017-07-01

    The types of instability in the interacting binary stars are briefly reviewed. The project “Inter-Longitude Astronomy” is a series of smaller projects on concrete stars or groups of stars. It has no special funds, and is supported from resources and grants of participating organizations, when informal working groups are created. This “ILA” project is in some kind similar and complementary to other projects like WET, CBA, UkrVO, VSOLJ, BRNO, MEDUZA, AstroStatistics, where many of us collaborate. Totally we studied 1900+ variable stars of different types, including newly discovered variables. The characteristic timescale is from seconds to decades and (extrapolating) even more. The monitoring of the first star of our sample AM Her was initiated by Prof. V.P. Tsesevich (1907-1983). Since more than 358 ADS papers were published. In this short review, we present some highlights of our photometric and photo-polarimetric monitoring and mathematical modeling of interacting binary stars of different types: classical (AM Her, QQ Vul, V808 Aur = CSS 081231:071126+440405, FL Cet), asynchronous (BY Cam, V1432 Aql), intermediate (V405 Aql, BG CMi, MU Cam, V1343 Her, FO Aqr, AO Psc, RXJ 2123, 2133, 0636, 0704) polars and magnetic dwarf novae (DO Dra) with 25 timescales corresponding to different physical mechanisms and their combinations (part “Polar”); negative and positive superhumpers in nova-like (TT Ari, MV Lyr, V603 Aql, V795 Her) and many dwarf novae stars (“Superhumper”); eclipsing “non-magnetic” cataclysmic variables(BH Lyn, DW UMa, EM Cyg; PX And); symbiotic systems (“Symbiosis”); super-soft sources (SSS, QR And); spotted (and not spotted) eclipsing variables with (and without) evidence for a current mass transfer (“Eclipser”) with a special emphasis on systems with a direct impact of the stream into the gainer star's atmosphere, which we propose to call “Impactor” (short from “Extreme Direct Impactor”), or V361 Lyr-type stars. Other

  4. Binary neutron star merger simulations

    Energy Technology Data Exchange (ETDEWEB)

    Bruegmann, Bernd [Jena Univ. (Germany)

    2016-11-01

    Our research focuses on the numerical tools necessary to solve Einstein's equations. In recent years we have been particularly interested in spacetimes consisting of two neutron stars in the final stages of their evolution. Because of the emission of gravitational radiation, the objects are driven together to merge; the emitted gravitational wave signal is visualized. This emitted gravitational radiation carries energy and momentum away from the system and contains information about the system. Late last year the Laser Interferometer Gravitational-wave Observatory (LIGO) began searches for these gravitational wave signals at a sensitivity at which detections are expected. Although such systems can radiate a significant amount of their total mass-energy in gravitational waves, the gravitational wave signals one expects to receive on Earth are not strong, since sources of gravitational waves are often many millions of light years away. Therefore one needs accurate templates for the radiation one expects from such systems in order to be able to extract them out of the detector's noise. Although analytical models exist for compact binary systems when the constituents are well separated, we need numerical simulation to investigate the last orbits before merger to obtain accurate templates and validate analytical approximations. Due to the strong nonlinearity of the equations and the large separation of length scales, these simulations are computationally demanding and need to be run on large supercomputers. When matter is present the computational cost as compared to pure black hole (vacuum) simulations increases even more due to the additional matter fields. But also more interesting astrophysical phenomena can happen. In fact, there is the possibility for a strong electromagnetic signal from the merger (e.g., a short gamma-ray burst or lower-energy electromagnetic signatures from the ejecta) and significant neutrino emission. Additionally, we can expect that

  5. Eliciting Subjective Probabilities with Binary Lotteries

    DEFF Research Database (Denmark)

    Harrison, Glenn W.; Martínez-Correa, Jimmy; Swarthout, J. Todd

    2014-01-01

    We evaluate a binary lottery procedure for inducing risk neutral behavior in a subjective belief elicitation task. Prior research has shown this procedure to robustly induce risk neutrality when subjects are given a single risk task defined over objective probabilities. Drawing a sample from...... the same subject population, we find evidence that the binary lottery procedure also induces linear utility in a subjective probability elicitation task using the Quadratic Scoring Rule. We also show that the binary lottery procedure can induce direct revelation of subjective probabilities in subjects...

  6. Dixie Valley Bottoming Binary Unit

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, Dale [Terra-Gen Sierra Holdings, LLC, Reno, NV (United States)

    2014-12-21

    This binary plant is the first air cooled, high-output refrigeration based waste heat recovery cycle in the industry. Its working fluid is environmentally friendly and as such, the permits that would be required with a hydrocarbon based cycle are not necessary. The unit is largely modularized, meaning that the unit’s individual skids were assembled in another location and were shipped via truck to the plant site. The Air Cooled Condensers (ACC), equipment piping, and Balance of Plant (BOP) piping were constructed at site. This project further demonstrates the technical feasibility of using low temperature brine for geothermal power utilization. The development of the unit led to the realization of low temperature, high output, and environmentally friendly heat recovery systems through domestic research and engineering. The project generates additional renewable energy, resulting in cleaner air and reduced carbon dioxide emissions. Royalty and tax payments to governmental agencies will increase, resulting in reduced financial pressure on local entities. The major components of the unit were sourced from American companies, resulting in increased economic activity throughout the country.

  7. Enhanced parametric processes in binary metamaterials

    OpenAIRE

    Gorkunov, Maxim V.; Shadrivov, Ilya V.; Kivshar, Yuri S.

    2005-01-01

    We suggest double-resonant (binary) metamaterials composed of two types of magnetic resonant elements, and demonstrate that in the nonlinear regime such metamaterials provide unique possibilities for phase-matched parametric interaction and enhanced second-harmonic generation.

  8. BINARY MINOR PLANETS V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — We present a data table giving basic physical and orbital parameters for known binary minor planets in the Solar System (and Pluto/Charon) based on published...

  9. BINARY MINOR PLANETS V6.0

    Data.gov (United States)

    National Aeronautics and Space Administration — The data set lists orbital and physical properties for well-observed or suspected binary/multiple minor planets including the Pluto system, as inspired by Richardson...

  10. BINARY MINOR PLANETS V4.0

    Data.gov (United States)

    National Aeronautics and Space Administration — The data set lists orbital and physical properties for well-observed or suspected binary/multiple minor planets including the Pluto system, as inspired by Richardson...

  11. BINARY MINOR PLANETS V5.0

    Data.gov (United States)

    National Aeronautics and Space Administration — The data set lists orbital and physical properties for well-observed or suspected binary/multiple minor planets including the Pluto system, as inspired by Richardson...

  12. BINARY MINOR PLANETS V8.0

    Data.gov (United States)

    National Aeronautics and Space Administration — The data set lists orbital and physical properties for well-observed or suspected binary/multiple minor planets including the Pluto system, compiled from the...

  13. BINARY MINOR PLANETS V9.0

    Data.gov (United States)

    National Aeronautics and Space Administration — The data set lists orbital and physical properties for well-observed or suspected binary/multiple minor planets including the Pluto system, compiled from the...

  14. BINARY MINOR PLANETS V7.0

    Data.gov (United States)

    National Aeronautics and Space Administration — The data set lists orbital and physical properties for well-observed or suspected binary/multiple minor planets including the Pluto system, compiled from the...

  15. BINARY MINOR PLANETS V2.0

    Data.gov (United States)

    National Aeronautics and Space Administration — We present data tables giving basic orbital and physical parameters for well-observed or suspected binary/multiple minor planets and the Pluto system, based on a...

  16. BINARY MINOR PLANETS V3.0

    Data.gov (United States)

    National Aeronautics and Space Administration — We present data tables giving basic orbital and physical parameters for well-observed or suspected binary/multiple minor planets and the Pluto system, based on a...

  17. A Type System for Certified Binaries

    National Research Council Canada - National Science Library

    Shao, Zhong; Trifonov, Valery; Saha, Bratin; Papaspyrou, Nikolaos

    2004-01-01

    ... (CPS and closure conversion) while preserving proofs represented in the type system. Our work provides a foundation for the process of automatically generating certified binaries in a type-theoretic framework.

  18. ON THE BINARY DIGITS OF ALGEBRAIC NUMBERS

    OpenAIRE

    KANEKO, HAJIME

    2010-01-01

    Borel conjectured that all algebraic irrational numbers are normal in base 2. However, very little is known about this problem. We improve the lower bounds for the number of digit changes in the binary expansions of algebraic irrational numbers.

  19. General simulation algorithm for autocorrelated binary processes

    Science.gov (United States)

    Serinaldi, Francesco; Lombardo, Federico

    2017-02-01

    The apparent ubiquity of binary random processes in physics and many other fields has attracted considerable attention from the modeling community. However, generation of binary sequences with prescribed autocorrelation is a challenging task owing to the discrete nature of the marginal distributions, which makes the application of classical spectral techniques problematic. We show that such methods can effectively be used if we focus on the parent continuous process of beta distributed transition probabilities rather than on the target binary process. This change of paradigm results in a simulation procedure effectively embedding a spectrum-based iterative amplitude-adjusted Fourier transform method devised for continuous processes. The proposed algorithm is fully general, requires minimal assumptions, and can easily simulate binary signals with power-law and exponentially decaying autocorrelation functions corresponding, for instance, to Hurst-Kolmogorov and Markov processes. An application to rainfall intermittency shows that the proposed algorithm can also simulate surrogate data preserving the empirical autocorrelation.

  20. Computer controlled evaluation of binary images

    NARCIS (Netherlands)

    Schouten, Th.E.; van den Broek, Egon

    2010-01-01

    The present invention relates to computer controlled image processing and, in particular, to computer controlled evaluation of two dimensional, 2D, and three dimensional, 3D, binary images including sequences of images using a distance map.

  1. On the Maximum Separation of Visual Binaries

    Indian Academy of Sciences (India)

    2016-01-27

    minimum) angular separation ρmax(ρmin), the corresponding apparent position angles (|ρmax , |ρmin) and the individual masses of visual binary systems. The algorithm uses Reed's formulae (1984) for the masses, and a ...

  2. Red-giant stars in eccentric binaries

    Directory of Open Access Journals (Sweden)

    Beck P. G.

    2015-01-01

    Full Text Available The unparalleled photometric data obtained by NASA’s Kepler Space Telescope has led to improved understanding of red-giant stars and binary stars. We discuss the characterization of known eccentric system, containing a solar-like oscillating red-giant primary component. We also report several new binary systems that are candidates for hosting an oscillating companion. A powerful approach to study binary stars is to combine asteroseimic techniques with light curve fitting. Seismology allows us to deduce the properties of red giants. In addition, by modeling the ellipsoidal modulations we can constrain the parameters of the binary system. An valuable independent source are ground-bases, high-resolution spectrographs.

  3. Observations of new Wolf-Rayet binaries

    International Nuclear Information System (INIS)

    Niemela, V.S.

    1982-01-01

    The author reports here preliminary results of spectrographic observations for three southern WR stars, whose binary nature had not been previously verified: HDE 320102, CD -45 0 4482, HD 62910. The observations were carried out at the Cerro Tololo Inter-American Observatory, Chile, mostly with the Cassegrain spectrograph with IT attached to the 1-m reflector. These spectrograms were secured on Kodak IIIaJ emulsion, and have a dispersion of 45 A/mm. The results suggest that HDE 320102 must be a double-lined 05-7 + WN3 spectroscopic binary, that CD -45 0 4482 appears to be a single-lined spectroscopic binary and that HD 62910 may be a binary. (Auth.)

  4. Diffusion in ordered binary solid systems

    International Nuclear Information System (INIS)

    Stolwijk, N.A.

    1980-01-01

    This thesis contains contributions to the field of diffusion in ordered binary solid systems. An extensive experimental investigation of the self diffusion in CoGa is presented. The results of these diffusion measurements strongly suggest that a substantial part of the atomic migration is caused by a new type of defect. A quantitative description of the atomic displacements via this defect is given. Finally computer simulations are presented of diffusion and ordering in binary solid systems. (Auth.)

  5. Reflection effect in close binary systems

    International Nuclear Information System (INIS)

    Vanlandingham, F.G.

    1974-01-01

    The investigation studies the effects of the irradiation of the hotter component in a close binary system on the atmosphere of the secondary and on the observed flux distribution of the binary system. An existing model atmospheres computer program is modified to include the effects of non-zero incident radiation. Computations reveal that the irradiation can significantly raise the temperature in the upper layers of the atmosphere. (U.S.)

  6. Detecting Black Hole Binaries by Gaia

    OpenAIRE

    Yamaguchi, Masaki S.; Kawanaka, Norita; Bulik, Tomasz; Piran, Tsvi

    2017-01-01

    We study the prospect of the Gaia satellite to identify black hole binary systems by detecting the orbital motion of the companion stars. Taking into account the initial mass function, mass transfer, common envelope phase, interstellar absorption and identifiability of black holes, we estimate the number of black hole binaries detected by Gaia and their distributions with respect to the black hole mass for several models with different parameters. We find that $\\sim 300-6000$ black hole binar...

  7. Search for binary nuclei in planetary nebulae

    International Nuclear Information System (INIS)

    Jasniewicz, G.

    1987-01-01

    Two planetary nebulae with central stars of late spectral type were observed: LT 5 and Abell 35. The variation of the systemic velocity of the G-binary in HD 112313 gives strong support to the idea of a third body in the nucleus of LT 5. In addition, it is concluded that observed photometric variations of BD -22 deg 3467 (the central star of Abell 35) can best be explained by the binary nature of the star. 9 references

  8. Search for binary nuclei in planetary nebulae

    Science.gov (United States)

    Jasniewicz, G.

    Two planetary nebulae with central stars of late spectral type were observed: LT 5 and Abell 35. The variation of the systemic velocity of the G-binary in HD 112313 gives strong support to the idea of a third body in the nucleus of LT 5. In addition, it is concluded that observed photometric variations of BD -22 deg 3467 (the central star of Abell 35) can best be explained by the binary nature of the star.

  9. New algorithms for binary wavefront optimization

    Science.gov (United States)

    Zhang, Xiaolong; Kner, Peter

    2015-03-01

    Binary amplitude modulation promises to allow rapid focusing through strongly scattering media with a large number of segments due to the faster update rates of digital micromirror devices (DMDs) compared to spatial light modulators (SLMs). While binary amplitude modulation has a lower theoretical enhancement than phase modulation, the faster update rate should more than compensate for the difference - a factor of π2 /2. Here we present two new algorithms, a genetic algorithm and a transmission matrix algorithm, for optimizing the focus with binary amplitude modulation that achieve enhancements close to the theoretical maximum. Genetic algorithms have been shown to work well in noisy environments and we show that the genetic algorithm performs better than a stepwise algorithm. Transmission matrix algorithms allow complete characterization and control of the medium but require phase control either at the input or output. Here we introduce a transmission matrix algorithm that works with only binary amplitude control and intensity measurements. We apply these algorithms to binary amplitude modulation using a Texas Instruments Digital Micromirror Device. Here we report an enhancement of 152 with 1536 segments (9.90%×N) using a genetic algorithm with binary amplitude modulation and an enhancement of 136 with 1536 segments (8.9%×N) using an intensity-only transmission matrix algorithm.

  10. Eclipsing Binary B-Star Mass Determinations

    Science.gov (United States)

    Townsend, Amanda; Eikenberry, Stephen S.

    2016-01-01

    B-stars in binary pairs provide a laboratory for key astrophysical measurements of massive stars, including key insights for the formation of compact objects (neutron stars and black holes). In their paper, Martayan et al (2004) find 23 Be binary star pairs in NGC2004 in the Large Magellanic Cloud, five of which are both eclipsing and spectroscopic binaries with archival data from VLT-Giraffe and photometric data from MACHO. By using the Wilson eclipsing binary code (e.g., Wilson, 1971), we can determine preliminary stellar masses of the binary components. We present the first results from this analysis. This study also serves as proof-of-concept for future observations with the Photonic Synthesis Telescope Array (Eikenberry et al., in prep) that we are currently building for low-cost, precision spectroscopic observations. With higher resolution and dedicated time for observations, we can follow-up observations of these Be stars as well as Be/X-ray binaries, for improved mass measurements of neutron stars and black holes and better constraints on their origin/formation.

  11. Texture classification by texton: statistical versus binary.

    Directory of Open Access Journals (Sweden)

    Zhenhua Guo

    Full Text Available Using statistical textons for texture classification has shown great success recently. The maximal response 8 (Statistical_MR8, image patch (Statistical_Joint and locally invariant fractal (Statistical_Fractal are typical statistical texton algorithms and state-of-the-art texture classification methods. However, there are two limitations when using these methods. First, it needs a training stage to build a texton library, thus the recognition accuracy will be highly depended on the training samples; second, during feature extraction, local feature is assigned to a texton by searching for the nearest texton in the whole library, which is time consuming when the library size is big and the dimension of feature is high. To address the above two issues, in this paper, three binary texton counterpart methods were proposed, Binary_MR8, Binary_Joint, and Binary_Fractal. These methods do not require any training step but encode local feature into binary representation directly. The experimental results on the CUReT, UIUC and KTH-TIPS databases show that binary texton could get sound results with fast feature extraction, especially when the image size is not big and the quality of image is not poor.

  12. Study of polymorphic control in an ethanol-water binary solvent

    Science.gov (United States)

    Kitano, Hiroshi; Tanaka, Takayuki; Hirasawa, Izumi

    2017-07-01

    Three polymorphs of L-Citrulline crystals, anhydrate (Form α, γ and δ) and pseudo polymorph (dihydrate), were confirmed. In this study, polymorphic control of L-Citrulline was attempted by changing the ethanol concentration in ethanol-water binary solvents. First, each polymorph of L-Citrulline crystals was added to the prepared ethanol-water binary solvents and samples which were obtained chronologically were measured by XRD. Also, the crystal sizes and shapes in transformation were observed by microscope. Then, polymorphs of the crystals after transformation were determined by XRD pattern. As a result, the transformation from dihydrate to anhydrate was observed by adding dihydrate crystals to the ethanol-water binary solvent. Similarly, the transformation from anhydrate to another anhydrate was observed. Especially in the case of adding dihydrate, the existences of all polymorphs were confirmed by adjusting ethanol-water binary solvent. According to the results, it was revealed that polymorphic transformation was affected by the trace amount of water contained in ethanol-water binary solvent. Moreover, transformation from dihydrate to anhydrate was constructed with three phases, dissolution of dihydrate, nucleation and growth of anhydrate. Therefore, the solution-mediated polymorphic transformation was supposed to be a key mechanism for this transformation.

  13. Fluorescence resonance energy transfer in a binary organic nanoparticle system and its application.

    Science.gov (United States)

    Wu, Meng; Xu, Xinjun; Wang, Jinshan; Li, Lidong

    2015-04-22

    Fluorescent organic nanoparticles have a much better photostability than molecule-based probes. Here, we report a simple strategy to detect chemicals and biomolecules by a binary nanoparticle system based on fluorescence resonance energy transfer (FRET). Poly(9,9-di-n-octylfluorenyl-2,7-diyl) (PFO, energy donor) and poly [2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV, energy acceptor) are utilized to prepare the binary nanoparticle system through a reprecipitation method. Since the FRET process is strongly distance-dependent, a change in the interparticle distance between the two kinds of nanoparticles after introduction of analytes will alter the FRET efficiency. The response of the binary nanoparticle system to cationic polyelectrolytes was investigated by monitoring the FRET efficiency from PFO to MEH-PPV nanoparticles and the fluorescence color of the nanoparticle solutions. Furthermore, the cationic polyelectrolyte pretreated binary nanoparticle system can be used to detect DNA by desorption of nanoparticles from the polyelectrolyte's chains and the detection concentration can go down to 10(-14) M. Thus, the binary nanoparticle system shows great promise for applications in chemical sensing or biosensing.

  14. Binary mixing of micelles using Pluronics for a nano-sized drug delivery system.

    Science.gov (United States)

    Lee, Eun Seong; Oh, Young Taik; Youn, Yu Seok; Nam, Myounghwa; Park, Byungtae; Yun, Jungmin; Kim, Ji Hoon; Song, Ho-Taek; Oh, Kyung Taek

    2011-01-01

    Pluronics with different structural compositions and properties are used for several applications, including drug delivery systems. We developed a binary mixing system with two Pluronics, L121/P123, as a nano-sized drug delivery carrier. The lamellar-forming Pluronic L121 (0.1 wt%) was incorporated with Pluronic P123 to produce nano-sized dispersions (in case of 0.1 and 0.5 wt% P123) with high stability due to Pluronic P123 and high solubilization capacity due to Pluronic L121. The binary systems were spherical and less than 200-nm diameter, with high thermodynamic stability (at least 2 weeks) in aqueous solution. The CMC of the binary system was located in the middle of the CMC of each polymer. In particular, the solubilization capacity of the binary system (0.1/0.1 wt%) was higher than mono-systems of P123. The main advantage of binary systems is overcoming limitations of mono systems to allow tailored mixing of block copolymers with different physicochemical characteristics. These nano-sized systems may have potential as anticancer drug delivery systems with simple preparation method, high stability, and high loading capacity. Copyright © 2010 Elsevier B.V. All rights reserved.

  15. Improving quantum state transfer efficiency and entanglement distribution in binary tree spin network through incomplete collapsing measurements

    Science.gov (United States)

    Behzadi, Naghi; Ahansaz, Bahram

    2018-04-01

    We propose a mechanism for quantum state transfer (QST) over a binary tree spin network on the basis of incomplete collapsing measurements. To this aim, we perform initially a weak measurement (WM) on the central qubit of the binary tree network where the state of our concern has been prepared on that qubit. After the time evolution of the whole system, a quantum measurement reversal (QMR) is performed on a chosen target qubit. By taking optimal value for the strength of QMR, it is shown that the QST quality from the sending qubit to any typical target qubit on the binary tree is considerably improved in terms of the WM strength. Also, we show that how high-quality entanglement distribution over the binary tree network is achievable by using this approach.

  16. Exploring the Birth of Binary Stars

    Science.gov (United States)

    Kohler, Susanna

    2016-08-01

    More than half of all stars are thought to be in binary or multiple star systems. But how do these systems form? The misaligned spins of some binary protostars might provide a clue.Two Formation ModelsIts hard to tell how multiple-star systems form, since these systems are difficult to observe in their early stages. But based on numerical simulations, there are two proposed models for the formation of stellar binaries:Turbulent fragmentationTurbulence within a single core leads to multiple dense clumps. These clumps independently collapse to form stars that orbit each other.Disk fragmentationGravitational instabilities in a massive accretion disk cause the formation of a smaller, secondary disk within the first, resulting in two stars that orbit each other.Log column density for one of the authors simulated binary systems, just after the formation of two protostars. Diamonds indicate the protostar positions. [Adapted from Offner et al. 2016]Outflows as CluesHow can we differentiate between these formation mechanisms? Led by Stella Offner (University of Massachusetts), a team of scientists has suggested that the key isto examine the alignment of the stars protostellar outflows jets that are often emitted from the poles of young, newly forming stars.Naively, wed expect that disk fragmentation would produce binary stars with common angular momentum. As the stars spins would be aligned, they would therefore also launch protostellar jets that were aligned with each other. Turbulent fragmentation, on the other hand, would cause the stars to have independent angular momentum. This would lead to randomly oriented spins, so the protostellar jets would be misaligned.Snapshots from the authors simulations. Left panel of each pair: column density; green arrows giveprotostellar spin directions. Right panel: synthetic observations produced from the simulations; cyan arrows giveprotostellar outflow directions. [Offner et al. 2016]Simulations of FragmentationIn order to better

  17. Do stellar clusters form fewer binaries? Using moderate separation binaries to distinguish between nature and nurture

    Science.gov (United States)

    Reiter, Megan

    2017-08-01

    Fewer wide-separation binaries are found in dense stellar clusters than in looser stellar associations. It is therefore unclear whether feedback in clusters prevents the formation of multiple systems or dynamical interactions destroy them. Measuring the prevalence of close, bound binary systems provide a key test to distinguish between these possibilities. Systems with separations of 10-50 AU will survive interactions in the cluster environment, and therefore are more representative of the natal population of multiple systems. By fitting a double-star PSF, we will identify visual binaries in the Orion Nebula with separations as small as 0.03. At the distance of Orion, this corresponds to a physical separation of 12 AU, effectively closing the observational gap in the binary separation distribution left between known visual and spectroscopic binaries (>65 AU or PhD thesis.

  18. Satisfiability modulo theory and binary puzzle

    Science.gov (United States)

    Utomo, Putranto

    2017-06-01

    The binary puzzle is a sudoku-like puzzle with values in each cell taken from the set {0, 1}. We look at the mathematical theory behind it. A solved binary puzzle is an n × n binary array where n is even that satisfies the following conditions: (1) No three consecutive ones and no three consecutive zeros in each row and each column, (2) Every row and column is balanced, that is the number of ones and zeros must be equal in each row and in each column, (3) Every two rows and every two columns must be distinct. The binary puzzle had been proven to be an NP-complete problem [5]. Research concerning the satisfiability of formulas with respect to some background theory is called satisfiability modulo theory (SMT). An SMT solver is an extension of a satisfiability (SAT) solver. The notion of SMT can be used for solving various problem in mathematics and industries such as formula verification and operation research [1, 7]. In this paper we apply SMT to solve binary puzzles. In addition, we do an experiment in solving different sizes and different number of blanks. We also made comparison with two other approaches, namely by a SAT solver and exhaustive search.

  19. Star formation history: Modeling of visual binaries

    Science.gov (United States)

    Gebrehiwot, Y. M.; Tessema, S. B.; Malkov, O. Yu.; Kovaleva, D. A.; Sytov, A. Yu.; Tutukov, A. V.

    2018-05-01

    Most stars form in binary or multiple systems. Their evolution is defined by masses of components, orbital separation and eccentricity. In order to understand star formation and evolutionary processes, it is vital to find distributions of physical parameters of binaries. We have carried out Monte Carlo simulations in which we simulate different pairing scenarios: random pairing, primary-constrained pairing, split-core pairing, and total and primary pairing in order to get distributions of binaries over physical parameters at birth. Next, for comparison with observations, we account for stellar evolution and selection effects. Brightness, radius, temperature, and other parameters of components are assigned or calculated according to approximate relations for stars in different evolutionary stages (main-sequence stars, red giants, white dwarfs, relativistic objects). Evolutionary stage is defined as a function of system age and component masses. We compare our results with the observed IMF, binarity rate, and binary mass-ratio distributions for field visual binaries to find initial distributions and pairing scenarios that produce observed distributions.

  20. Stacking Analysis of Binary Systems with HAWC

    Science.gov (United States)

    Brisbois, Chad; HAWC Collaboration

    2017-01-01

    Detecting binary systems at TeV energies is an important problem because only a handful of such systems are currently known. The nature of such systems is typically thought to be composed of a compact object and a massive star. The TeV emission from these systems does not obviously correspond to emission in GeV or X-ray, where many binary systems have previously been found. This study focuses on a stacking method to detect TeV emission from LS 5039, a known TeV binary, to test its efficacy in HAWC data. Stacking is a widely employed method for increasing signal to noise ratio in optical astronomy, but has never been attempted previously with HAWC. HAWC is an ideal instrument to search for TeV binaries, because of its wide field of view and high uptime. Applying this method to the entire sky may allow HAWC to detect binary sources of very short or very long periods not sensitive to current analyses. NSF, DOE, Los Alamos, Michigan Tech, CONACyt, UNAM, BUAP.

  1. EVOLUTION OF THE BINARY FRACTION IN DENSE STELLAR SYSTEMS

    International Nuclear Information System (INIS)

    Fregeau, John M.; Ivanova, Natalia; Rasio, Frederic A.

    2009-01-01

    Using our recently improved Monte Carlo evolution code, we study the evolution of the binary fraction in globular clusters. In agreement with previous N-body simulations, we find generally that the hard binary fraction in the core tends to increase with time over a range of initial cluster central densities for initial binary fractions ∼<90%. The dominant processes driving the evolution of the core binary fraction are mass segregation of binaries into the cluster core and preferential destruction of binaries there. On a global scale, these effects and the preferential tidal stripping of single stars tend to roughly balance, leading to overall cluster binary fractions that are roughly constant with time. Our findings suggest that the current hard binary fraction near the half-mass radius is a good indicator of the hard primordial binary fraction. However, the relationship between the true binary fraction and the fraction of main-sequence stars in binaries (which is typically what observers measure) is nonlinear and rather complicated. We also consider the importance of soft binaries, which not only modify the evolution of the binary fraction, but can also drastically change the evolution of the cluster as a whole. Finally, we briefly describe the recent addition of single and binary stellar evolution to our cluster evolution code.

  2. Stability studies of colloidal silica dispersions in binary solvent mixtures

    CERN Document Server

    Bean, K H

    1997-01-01

    A series of monodispersed colloidal silica dispersions, of varying radii, has been prepared. These particles are hydrophilic in nature due to the presence of surface silanol groups. Some of the particles have been rendered hydrophobic by terminally grafting n-alkyl (C sub 1 sub 8) chains to the surface. The stability of dispersions of these various particles has been studied in binary mixtures of liquids, namely (i) ethanol and cyclohexane, and (ii) benzene and n-heptane. The ethanol - cyclohexane systems have been studied using a variety of techniques. Adsorption excess isotherms have been established and electrophoretic mobility measurements have been made. The predicted stability of the dispersions from D.V.L.O. calculations is compared to the observed stability. The hydrophilic silica particles behave as predicted by the calculations, with the zeta potential decreasing and the van der Waals attraction increasing with increasing cyclohexane concentration. The hydrophobic particles behave differently than e...

  3. TIDAL NOVAE IN COMPACT BINARY WHITE DWARFS

    International Nuclear Information System (INIS)

    Fuller, Jim; Lai Dong

    2012-01-01

    Compact binary white dwarfs (WDs) undergoing orbital decay due to gravitational radiation can experience significant tidal heating prior to merger. In these WDs, the dominant tidal effect involves the excitation of outgoing gravity waves in the inner stellar envelope and the dissipation of these waves in the outer envelope. As the binary orbit decays, the WDs are synchronized from outside in (with the envelope synchronized first, followed by the core). We examine the deposition of tidal heat in the envelope of a carbon-oxygen WD and study how such tidal heating affects the structure and evolution of the WD. We show that significant tidal heating can occur in the star's degenerate hydrogen layer. This layer heats up faster than it cools, triggering runaway nuclear fusion. Such 'tidal novae' may occur in all WD binaries containing a CO WD, at orbital periods between 5 minutes and 20 minutes, and precede the final merger by 10 5 -10 6 years.

  4. Compact binary hashing for music retrieval

    Science.gov (United States)

    Seo, Jin S.

    2014-03-01

    With the huge volume of music clips available for protection, browsing, and indexing, there is an increased attention to retrieve the information contents of the music archives. Music-similarity computation is an essential building block for browsing, retrieval, and indexing of digital music archives. In practice, as the number of songs available for searching and indexing is increased, so the storage cost in retrieval systems is becoming a serious problem. This paper deals with the storage problem by extending the supervector concept with the binary hashing. We utilize the similarity-preserving binary embedding in generating a hash code from the supervector of each music clip. Especially we compare the performance of the various binary hashing methods for music retrieval tasks on the widely-used genre dataset and the in-house singer dataset. Through the evaluation, we find an effective way of generating hash codes for music similarity estimation which improves the retrieval performance.

  5. Hybrid Black-Hole Binary Initial Data

    Science.gov (United States)

    Mundim, Bruno C.; Kelly, Bernard J.; Nakano, Hiroyuki; Zlochower, Yosef; Campanelli, Manuela

    2010-01-01

    "Traditional black-hole binary puncture initial data is conformally flat. This unphysical assumption is coupled with a lack of radiation signature from the binary's past life. As a result, waveforms extracted from evolutions of this data display an abrupt jump. In Kelly et al. [Class. Quantum Grav. 27:114005 (2010)], a new binary black-hole initial data with radiation contents derived in the post-Newtonian (PN) calculations was adapted to puncture evolutions in numerical relativity. This data satisfies the constraint equations to the 2.5PN order, and contains a transverse-traceless "wavy" metric contribution, violating the standard assumption of conformal flatness. Although the evolution contained less spurious radiation, there were undesired features; the unphysical horizon mass loss and the large initial orbital eccentricity. Introducing a hybrid approach to the initial data evaluation, we significantly reduce these undesired features."

  6. Development of binary technologies of radiotherapy of malignant neoplasms: condition and problems

    Directory of Open Access Journals (Sweden)

    Igor N. Sheino

    2017-01-01

    Full Text Available The review is devoted to the problems of the development of binary technologies of radiation therapy - neutron and photon-capture therapy of malignant neoplasms. These technologies are based on the principle of “biological” targeting: irradiation of a tumor with pre-delivered special preparations increasing energy release and the relative biological efficiency of primary radiation. The basis of methods, characteristics of sources of external irradiation and used preparations, and stages of development of technologies are described. The development and implementation of binary technologies attract a great number of researchers but are restrained by the shortage of operating sources of epithermal neutrons (reactors, neutron generators based on accelerators and the lack of accurate radiation dosimetry planning systems that takes into account the dynamics and accumulation of drugs in tumors.

  7. The dynamical evolution of binaries in clusters

    International Nuclear Information System (INIS)

    Heggie, D.C.

    1975-01-01

    Using information on the rates at which binaries suffer encounters in a stellar system (Heggie, 1974), the effects of such processes on the evolution of the system itself are studied. First considering systems with no binaries initially, it is shown that low-energy pairs attain a quasi-equilibrium distribution comparatively quickly. Their effect on the evolution of the cluster is negligible compared with that of two-body relaxation. In small systems energetic pairs may form sufficiently quickly to exercise a substantial effect on its development and on the escape rate, but in large systems their appearance is delayed until the evolution of the core is well advanced. In that case they appear to be responsible for arresting the collapse of the core at some stage. Binaries of low energy, even if present initially in large numbers, are likely to have at most only a temporary effect on the evolution of the system. High-energy pairs are not so easily destroyed, and so, if present initially, their effect is persistent. It competes with two-body relaxation especially when the fraction of such pairs and the total number-density are high, as in the core, where, in addition, binaries tend to congregate by mass segregation. When encounters with binaries become important, being mostly 'super-elastic' they enhance escape and lead to ejection of mass from the core into the halo, thus accelerating the rate at which mass is lost by tidal forces. It is difficult to decide observationally whether globular clusters possess sufficiently large numbers of binaries for these effects to be important. (Auth.)

  8. Sputtering yield calculation for binary target

    International Nuclear Information System (INIS)

    Jimenez-Rodriguez, J.J.; Rodriguez-Vidal, M.; Valles-Abarca, J.A.

    1979-01-01

    The generalization for binary targets, of the ideas proposed by Sigmund for monoatomic targets, leads to a set of coupled intergrodifferential equations for the sputtering functions. After moment decomposition, the final formulae are obtained by the standard method based on the Laplace Transform, where the inverse transform is made with the aid of asymptotic expansions in the limit of very high projectile energy as compared to the surface binding energy. The possible loss of stoichiometry for binary targets is analyzed. Comparison of computed values of sputtering yield for normal incidence, with experimental results shows good agreement. (author)

  9. Binary Sparse Phase Retrieval via Simulated Annealing

    Directory of Open Access Journals (Sweden)

    Wei Peng

    2016-01-01

    Full Text Available This paper presents the Simulated Annealing Sparse PhAse Recovery (SASPAR algorithm for reconstructing sparse binary signals from their phaseless magnitudes of the Fourier transform. The greedy strategy version is also proposed for a comparison, which is a parameter-free algorithm. Sufficient numeric simulations indicate that our method is quite effective and suggest the binary model is robust. The SASPAR algorithm seems competitive to the existing methods for its efficiency and high recovery rate even with fewer Fourier measurements.

  10. A simple model for binary star evolution

    International Nuclear Information System (INIS)

    Whyte, C.A.; Eggleton, P.P.

    1985-01-01

    A simple model for calculating the evolution of binary stars is presented. Detailed stellar evolution calculations of stars undergoing mass and energy transfer at various rates are reported and used to identify the dominant physical processes which determine the type of evolution. These detailed calculations are used to calibrate the simple model and a comparison of calculations using the detailed stellar evolution equations and the simple model is made. Results of the evolution of a few binary systems are reported and compared with previously published calculations using normal stellar evolution programs. (author)

  11. Testing the Binary Black Hole Nature of a Compact Binary Coalescence.

    Science.gov (United States)

    Krishnendu, N V; Arun, K G; Mishra, Chandra Kant

    2017-09-01

    We propose a novel method to test the binary black hole nature of compact binaries detectable by gravitational wave (GW) interferometers and, hence, constrain the parameter space of other exotic compact objects. The spirit of the test lies in the "no-hair" conjecture for black holes where all properties of a Kerr black hole are characterized by its mass and spin. The method relies on observationally measuring the quadrupole moments of the compact binary constituents induced due to their spins. If the compact object is a Kerr black hole (BH), its quadrupole moment is expressible solely in terms of its mass and spin. Otherwise, the quadrupole moment can depend on additional parameters (such as the equation of state of the object). The higher order spin effects in phase and amplitude of a gravitational waveform, which explicitly contains the spin-induced quadrupole moments of compact objects, hence, uniquely encode the nature of the compact binary. Thus, we argue that an independent measurement of the spin-induced quadrupole moment of the compact binaries from GW observations can provide a unique way to distinguish binary BH systems from binaries consisting of exotic compact objects.

  12. The fate of close encounters between binary stars and binary supermassive black holes

    Science.gov (United States)

    Wang, Yi-Han; Leigh, Nathan; Yuan, Ye-Fei; Perna, Rosalba

    2018-04-01

    The evolution of main-sequence binaries that reside in the Galactic Centre can be heavily influenced by the central supermassive black hole (SMBH). Due to these perturbative effects, the stellar binaries in dense environments are likely to experience mergers, collisions, or ejections through secular and/or non-secular interactions. More direct interactions with the central SMBH are thought to produce hypervelocity stars (HVSs) and tidal disruption events (TDEs). In this paper, we use N-body simulations to study the dynamics of stellar binaries orbiting a central SMBH primary with an outer SMBH secondary orbiting this inner triple. The effects of the secondary SMBH on the event rates of HVSs, TDEs, and stellar mergers are investigated, as a function of the SMBH-SMBH binary mass ratio. Our numerical experiments reveal that, relative to the isolated SMBH case, the TDE and HVS rates are enhanced for, respectively, the smallest and largest mass ratio SMBH-SMBH binaries. This suggests that the observed event rates of TDEs and HVSs have the potential to serve as a diagnostic of the mass ratio of a central SMBH-SMBH binary. The presence of a secondary SMBH also allows for the creation of hypervelocity binaries. Observations of these systems could thus constrain the presence of a secondary SMBH in the Galactic Centre.

  13. Titania and zirconia binary oxides as catalysts for total oxidation of ethyl acetate and methanol decomposition

    Czech Academy of Sciences Publication Activity Database

    Tsoncheva, T.; Mileva, A.; Issa, G.; Dimitrov, M.; Kovacheva, D.; Henych, Jiří; Kormunda, M.; Scotti, N.; Slušná, Michaela; Tolasz, Jakub; Štengl, Václav

    2018-01-01

    Roč. 6, č. 2 (2018), s. 2540-2550 ISSN 2213-3437 Grant - others:AV ČR(CZ) BAS-17-13 Program:Bilaterální spolupráce Institutional support: RVO:61388980 Keywords : Effect of preparation procedure * Ethyl acetate oxidation * Methanol decomposition * Titania-zirconia binary oxides Subject RIV: CA - Inorganic Chemistry OBOR OECD: Inorganic and nuclear chemistry

  14. Thermodynamic properties of binary melts of manganese(II) bromide with lithium, cesium, and francium bromides

    International Nuclear Information System (INIS)

    Kritskaya, E.B.; Burylev, B.P.; Mojsov, L.P.; Kritskij, V.E.

    2005-01-01

    Relaying on the experimentally ascertained linear dependence of the Gibbs excessive mole energies on alkali metal ordinal number in the systems MnBr 2 -MBr (M=Na, K, Rb), thermodynamic properties of the melts in binary systems MBr 2 -M'Br (M'=Li, Cs, Fr) were prepared. Concentration dependences of the Gibbs energies, and thermodynamic activities of compounds in the above systems at 1125 K were calculated [ru

  15. BINARIES MIGRATING IN A GASEOUS DISK: WHERE ARE THE GALACTIC CENTER BINARIES?

    International Nuclear Information System (INIS)

    Baruteau, C.; Lin, D. N. C.; Cuadra, J.

    2011-01-01

    The massive stars in the Galactic center inner arcsecond share analogous properties with the so-called Hot Jupiters. Most of these young stars have highly eccentric orbits and were probably not formed in situ. It has been proposed that these stars acquired their current orbits from the tidal disruption of compact massive binaries scattered toward the proximity of the central supermassive black hole. Assuming a binary star formed in a thin gaseous disk beyond 0.1 pc from the central object, we investigate the relevance of disk-satellite interactions to harden the binding energy of the binary, and to drive its inward migration. A massive, equal-mass binary star is found to become more tightly wound as it migrates inward toward the central black hole. The migration timescale is very similar to that of a single-star satellite of the same mass. The binary's hardening is caused by the formation of spiral tails lagging the stars inside the binary's Hill radius. We show that the hardening timescale is mostly determined by the mass of gas inside the binary's Hill radius and that it is much shorter than the migration timescale. We discuss some implications of the binary's hardening process. When the more massive (primary) components of close binaries eject most their mass through supernova explosion, their secondary stars may attain a range of eccentricities and inclinations. Such processes may provide an alternative unified scenario for the origin of the kinematic properties of the central cluster and S-stars in the Galactic center as well as the high-velocity stars in the Galactic halo.

  16. Neutron-Star-Black-Hole Binaries Produced by Binary-Driven Hypernovae.

    Science.gov (United States)

    Fryer, Chris L; Oliveira, F G; Rueda, J A; Ruffini, R

    2015-12-04

    Binary-driven hypernovae (BdHNe) within the induced gravitational collapse paradigm have been introduced to explain energetic (E_{iso}≳10^{52}  erg), long gamma-ray bursts (GRBs) associated with type Ic supernovae (SNe). The progenitor is a tight binary composed of a carbon-oxygen (CO) core and a neutron-star (NS) companion, a subclass of the newly proposed "ultrastripped" binaries. The CO-NS short-period orbit causes the NS to accrete appreciable matter from the SN ejecta when the CO core collapses, ultimately causing it to collapse to a black hole (BH) and producing a GRB. These tight binaries evolve through the SN explosion very differently than compact binaries studied in population synthesis calculations. First, the hypercritical accretion onto the NS companion alters both the mass and the momentum of the binary. Second, because the explosion time scale is on par with the orbital period, the mass ejection cannot be assumed to be instantaneous. This dramatically affects the post-SN fate of the binary. Finally, the bow shock created as the accreting NS plows through the SN ejecta transfers angular momentum, braking the orbit. These systems remain bound even if a large fraction of the binary mass is lost in the explosion (well above the canonical 50% limit), and even large kicks are unlikely to unbind the system. Indeed, BdHNe produce a new family of NS-BH binaries unaccounted for in current population synthesis analyses and, although they may be rare, the fact that nearly 100% remain bound implies that they may play an important role in the compact merger rate, important for gravitational waves that, in turn, can produce a new class of ultrashort GRBs.

  17. The Tarantula Massive Binary Monitoring. I. Observational campaign and OB-type spectroscopic binaries

    Science.gov (United States)

    Almeida, L. A.; Sana, H.; Taylor, W.; Barbá, R.; Bonanos, A. Z.; Crowther, P.; Damineli, A.; de Koter, A.; de Mink, S. E.; Evans, C. J.; Gieles, M.; Grin, N. J.; Hénault-Brunet, V.; Langer, N.; Lennon, D.; Lockwood, S.; Maíz Apellániz, J.; Moffat, A. F. J.; Neijssel, C.; Norman, C.; Ramírez-Agudelo, O. H.; Richardson, N. D.; Schootemeijer, A.; Shenar, T.; Soszyński, I.; Tramper, F.; Vink, J. S.

    2017-02-01

    Context. Massive binaries play a crucial role in the Universe. Knowing the distributions of their orbital parameters is important for a wide range of topics from stellar feedback to binary evolution channels and from the distribution of supernova types to gravitational wave progenitors, yet no direct measurements exist outside the Milky Way. Aims: The Tarantula Massive Binary Monitoring project was designed to help fill this gap by obtaining multi-epoch radial velocity (RV) monitoring of 102 massive binaries in the 30 Doradus region. Methods: In this paper we analyze 32 FLAMES/GIRAFFE observations of 93 O- and 7 B-type binaries. We performed a Fourier analysis and obtained orbital solutions for 82 systems: 51 single-lined (SB1) and 31 double-lined (SB2) spectroscopic binaries. Results: Overall, the binary fraction and orbital properties across the 30 Doradus region are found to be similar to existing Galactic samples. This indicates that within these domains environmental effects are of second order in shaping the properties of massive binary systems. A small difference is found in the distribution of orbital periods, which is slightly flatter (in log space) in 30 Doradus than in the Galaxy, although this may be compatible within error estimates and differences in the fitting methodology. Also, orbital periods in 30 Doradus can be as short as 1.1 d, somewhat shorter than seen in Galactic samples. Equal mass binaries (q> 0.95) in 30 Doradus are all found outside NGC 2070, the central association that surrounds R136a, the very young and massive cluster at 30 Doradus's core. Most of the differences, albeit small, are compatible with expectations from binary evolution. One outstanding exception, however, is the fact that earlier spectral types (O2-O7) tend to have shorter orbital periods than later spectral types (O9.2-O9.7). Conclusions: Our results point to a relative universality of the incidence rate of massive binaries and their orbital properties in the

  18. Solution preparation

    International Nuclear Information System (INIS)

    Seitz, M.G.

    1982-01-01

    Reviewed in this statement are methods of preparing solutions to be used in laboratory experiments to examine technical issues related to the safe disposal of nuclear waste from power generation. Each approach currently used to prepare solutions has advantages and any one approach may be preferred over the others in particular situations, depending upon the goals of the experimental program. These advantages are highlighted herein for three approaches to solution preparation that are currently used most in studies of nuclear waste disposal. Discussion of the disadvantages of each approach is presented to help a user select a preparation method for his particular studies. Also presented in this statement are general observations regarding solution preparation. These observations are used as examples of the types of concerns that need to be addressed regarding solution preparation. As shown by these examples, prior to experimentation or chemical analyses, laboratory techniques based on scientific knowledge of solutions can be applied to solutions, often resulting in great improvement in the usefulness of results

  19. BinCat: a Catalog of Nearby Binary Stars with Tools for Calculating Light-Leakage for Direct Imaging Missions

    Science.gov (United States)

    Holte, Elias Peter; Sirbu, Dan; Belikov, Ruslan

    2018-01-01

    Binary stars have been largely left out of direct imaging surveys for exoplanets, specifically for earth-sized planets in their star's habitable zone. Utilizing new direct imaging techniques brings us closer to being able to detect earth-like exoplanets around binary stars. In preparation for the upcoming WFIRST mission and other direct imaging-capable missions (HabEx, LUVIOR) it is important to understand the expected science yield resulting from the implementation of these imaging techniques. BinCat is a catalog of binary systems within 30 parsecs to be used as a target list for future direct imaging missions. There is a non-static component along with BinCat that allows researchers to predict the expected light-leakage between a binary component and its off-axis companion (a value critical to the aforementioned techniques) at any epoch. This is accomplished by using orbital elements from the Sixth Orbital Catalog to model the orbits of the binaries. The software was validated against the historical data used to generate the orbital parameters. When orbital information is unknown or the binaries are purely optical the proper motion of the pair taken from the Washington Double Star catalog is integrated in time to estimate expected light-leakage.

  20. A coinductive calculus of binary trees

    NARCIS (Netherlands)

    A.M. Silva (Alexandra); J.J.M.M. Rutten (Jan)

    2007-01-01

    htmlabstractWe study the set T_A of infinite binary trees with nodes labelled in a semiring A from a coalgebraic perspective. We present coinductive definition and proof principles based on the fact that T_A carries a final coalgebra structure. By viewing trees as formal power series, we develop a

  1. ANGULAR-MOMENTUM IN BINARY SPIRAL GALAXIES

    NARCIS (Netherlands)

    OOSTERLOO, T

    In order to investigate the relative orientations of spiral galaxies in pairs, the distribution of the angle between the spin-vectors for a new sample of 40 binary spiral galaxies is determined. From this distribution it is found, contrary to an earlier result obtained by Helou (1984), that there is

  2. Short-timescale variability in cataclysmic binaries

    International Nuclear Information System (INIS)

    Cordova, F.A.; Mason, K.O.

    1982-01-01

    Rapid variability, including flickering and pulsations, has been detected in cataclysmic binaries at optical and x-ray frequencies. In the case of the novalike variable TT Arietis, simultaneous observations reveal that the x-ray and optical flickering activity is strongly correlated, while short period pulsations are observed that occur at the same frequencies in both wavelength bands

  3. Binary palmprint representation for feature template protection

    NARCIS (Netherlands)

    Mu, Meiru; Ruan, Qiuqi; Shao, X.; Spreeuwers, Lieuwe Jan; Veldhuis, Raymond N.J.

    2012-01-01

    The major challenge of biometric template protection comes from the intraclass variations of biometric data. The helper data scheme aims to solve this problem by employing the Error Correction Codes (ECC). However, many reported biometric binary features from the same user reach bit error rate (BER)

  4. Binary translation using peephole translation rules

    Science.gov (United States)

    Bansal, Sorav; Aiken, Alex

    2010-05-04

    An efficient binary translator uses peephole translation rules to directly translate executable code from one instruction set to another. In a preferred embodiment, the translation rules are generated using superoptimization techniques that enable the translator to automatically learn translation rules for translating code from the source to target instruction set architecture.

  5. Receptive fields selection for binary feature description.

    Science.gov (United States)

    Fan, Bin; Kong, Qingqun; Trzcinski, Tomasz; Wang, Zhiheng; Pan, Chunhong; Fua, Pascal

    2014-06-01

    Feature description for local image patch is widely used in computer vision. While the conventional way to design local descriptor is based on expert experience and knowledge, learning-based methods for designing local descriptor become more and more popular because of their good performance and data-driven property. This paper proposes a novel data-driven method for designing binary feature descriptor, which we call receptive fields descriptor (RFD). Technically, RFD is constructed by thresholding responses of a set of receptive fields, which are selected from a large number of candidates according to their distinctiveness and correlations in a greedy way. Using two different kinds of receptive fields (namely rectangular pooling area and Gaussian pooling area) for selection, we obtain two binary descriptors RFDR and RFDG .accordingly. Image matching experiments on the well-known patch data set and Oxford data set demonstrate that RFD significantly outperforms the state-of-the-art binary descriptors, and is comparable with the best float-valued descriptors at a fraction of processing time. Finally, experiments on object recognition tasks confirm that both RFDR and RFDG successfully bridge the performance gap between binary descriptors and their floating-point competitors.

  6. Flip-flopping binary black holes.

    Science.gov (United States)

    Lousto, Carlos O; Healy, James

    2015-04-10

    We study binary spinning black holes to display the long term individual spin dynamics. We perform a full numerical simulation starting at an initial proper separation of d≈25M between equal mass holes and evolve them down to merger for nearly 48 orbits, 3 precession cycles, and half of a flip-flop cycle. The simulation lasts for t=20 000M and displays a total change in the orientation of the spin of one of the black holes from an initial alignment with the orbital angular momentum to a complete antialignment after half of a flip-flop cycle. We compare this evolution with an integration of the 3.5 post-Newtonian equations of motion and spin evolution to show that this process continuously flip flops the spin during the lifetime of the binary until merger. We also provide lower order analytic expressions for the maximum flip-flop angle and frequency. We discuss the effects this dynamics may have on spin growth in accreting binaries and on the observational consequences for galactic and supermassive binary black holes.

  7. Predicting Social Trust with Binary Logistic Regression

    Science.gov (United States)

    Adwere-Boamah, Joseph; Hufstedler, Shirley

    2015-01-01

    This study used binary logistic regression to predict social trust with five demographic variables from a national sample of adult individuals who participated in The General Social Survey (GSS) in 2012. The five predictor variables were respondents' highest degree earned, race, sex, general happiness and the importance of personally assisting…

  8. Compiler-Agnostic Function Detection in Binaries

    NARCIS (Netherlands)

    Andriesse, D.A.; Slowinska, J.M.; Bos, H.J.

    2017-01-01

    We propose Nucleus, a novel function detection algorithm for binaries. In contrast to prior work, Nucleus is compiler-agnostic, and does not require any learning phase or signature information. Instead of scanning for signatures, Nucleus detects functions at the Control Flow Graph-level, making it

  9. Non-binary or genderqueer genders.

    Science.gov (United States)

    Richards, Christina; Bouman, Walter Pierre; Seal, Leighton; Barker, Meg John; Nieder, Timo O; T'Sjoen, Guy

    2016-01-01

    Some people have a gender which is neither male nor female and may identify as both male and female at one time, as different genders at different times, as no gender at all, or dispute the very idea of only two genders. The umbrella terms for such genders are 'genderqueer' or 'non-binary' genders. Such gender identities outside of the binary of female and male are increasingly being recognized in legal, medical and psychological systems and diagnostic classifications in line with the emerging presence and advocacy of these groups of people. Population-based studies show a small percentage--but a sizable proportion in terms of raw numbers--of people who identify as non-binary. While such genders have been extant historically and globally, they remain marginalized, and as such--while not being disorders or pathological in themselves--people with such genders remain at risk of victimization and of minority or marginalization stress as a result of discrimination. This paper therefore reviews the limited literature on this field and considers ways in which (mental) health professionals may assist the people with genderqueer and non-binary gender identities and/or expressions they may see in their practice. Treatment options and associated risks are discussed.

  10. Statistics of clusters in binary linear lattices

    NARCIS (Netherlands)

    Felderhof, B.U.

    The statistics of clusters in binary linear lattices is studied on the assumption that the relative weight of an Al or Bm cluster is determined only by its size l or m, and is independent of the location of the cluster on the chain. The average cluster numbers and the variance of their fluctuations

  11. Planar quark diagrams and binary spin processes

    International Nuclear Information System (INIS)

    Grigoryan, A.A.; Ivanov, N.Ya.

    1986-01-01

    Contributions of planar diagrams to the binary scattering processes are analyzed. The analysis is based on the predictions of quark-gluon picture of strong interactions for the coupling of reggeons with quarks as well as on the SU(6)-classification of hadrons. The dependence of contributions of nonplanar corrections on spins and quark composition of interacting particles is discussed

  12. Binary nucleation of water and sodium chloride

    Czech Academy of Sciences Publication Activity Database

    Němec, Tomáš; Maršík, František; Palmer, A.

    2006-01-01

    Roč. 124, č. 4 (2006), 0445091-0445096 ISSN 0021-9606 R&D Projects: GA ČR(CZ) GA101/05/2536 Institutional research plan: CEZ:AV0Z20760514 Keywords : binary nucleation * sodium chloride * water Subject RIV: BJ - Thermodynamics Impact factor: 3.166, year: 2006

  13. The average size of ordered binary subgraphs

    NARCIS (Netherlands)

    van Leeuwen, J.; Hartel, Pieter H.

    To analyse the demands made on the garbage collector in a graph reduction system, the change in size of an average graph is studied when an arbitrary edge is removed. In ordered binary trees the average number of deleted nodes as a result of cutting a single edge is equal to the average size of a

  14. Void formation in irradiated binary nickel alloys

    International Nuclear Information System (INIS)

    Shaikh, M.A.; Ahmed, M.; Akhter, J.I.

    1994-01-01

    In this work a computer program has been used to compute void radius, void density and swelling parameter for nickel and binary nickel-carbon alloys irradiated with nickel ions of 100 keV. The aim is to compare the computed results with experimental results already reported

  15. The Benchmark Eclipsing Binary V530 Ori

    DEFF Research Database (Denmark)

    Torres, Guillermo; Lacy, Claud H. Sandberg; Pavlovski, Kresimir

    2015-01-01

    We report accurate measurements of the physical properties (mass, radius, temperature) of components of the G+M eclipsing binary V530 On. The M-type secondary shows a larger radius and a cooler temperature than predicted by standard stellar evolution models, as has been found for many other low...

  16. Solid-state characterization of paracetamol metastable polymorphs formed in binary mixtures with hydroxypropylmethylcellulose

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, Alessandra; Savioli, Alessandra; Bini, Marcella; Capsoni, Doretta; Massarotti, Vincenzo; Bettini, Ruggero; Gazzaniga, Andrea; Sangalli, Maria Edvige; Giordano, Ferdinando

    2003-11-28

    Two metastable polymorphs of paracetamol (forms II and III) were prepared by appropriate thermal methods from binary mixtures containing 10% (w/w) of hydroxypropylmethylcellulose. By controlling the reheating step, it was possible to address the recrystallization of the drug either into form II or III. Moreover, it was observed that form III transforms either into form II or I depending on the preparation method. The physical characterization of the polymorphs was performed by means of micro-Fourier transform infrared spectroscopy (MFTIR) and powder X-ray diffractometry (PXRD), both temperature controlled.

  17. Terrestrial Planet Formation Around Individual Stars Within Binary Star Systems

    OpenAIRE

    Quintana, Elisa V.; Adams, Fred C.; Lissauer, Jack J.; Chambers, John E.

    2007-01-01

    We calculate herein the late stages of terrestrial planet accumulation around a solar type star that has a binary companion with semimajor axis larger than the terrestrial planet region. We perform more than one hundred simulations to survey binary parameter space and to account for sensitive dependence on initial conditions in these dynamical systems. As expected, sufficiently wide binaries leave the planet formation process largely unaffected. As a rough approximation, binary stars with per...

  18. Orbital synchronization capture of two binaries emitting gravitational waves

    Science.gov (United States)

    Seto, Naoki

    2018-03-01

    We study the possibility of orbital synchronization capture for a hierarchical quadrupole stellar system composed by two binaries emitting gravitational waves. Based on a simple model including the mass transfer for white dwarf binaries, we find that the capture might be realized for inter-binary distances less than their gravitational wavelength. We also discuss related intriguing phenomena such as a parasitic relation between the coupled white dwarf binaries and significant reductions of gravitational and electromagnetic radiations.

  19. Influence of non-binary effects on intranuclear cascade method

    International Nuclear Information System (INIS)

    Gomes, E.H.C.

    1985-01-01

    The importance of non binary process effects in the intranuclear cascade method is analysed. It is shown that, in the higher density steps, the non binary collisions lead to baryon density distribution and rapidity differents from the one obtained using the usual intranuclear cascade method (limited to purely binary collisions). The validity of the applications of binary intranuclear cascade method to the simulation of the thermal equilibrium, nuclear transparency and particle production, is discussed. (M.C.K.) [pt

  20. Gravitational waves from spinning eccentric binaries

    Science.gov (United States)

    Csizmadia, Péter; Debreczeni, Gergely; Rácz, István; Vasúth, Mátyás

    2012-12-01

    This paper is to introduce a new software called CBwaves which provides a fast and accurate computational tool to determine the gravitational waveforms yielded by generic spinning binaries of neutron stars and/or black holes on eccentric orbits. This is done within the post-Newtonian (PN) framework by integrating the equations of motion and the spin precession equations, while the radiation field is determined by a simultaneous evaluation of the analytic waveforms. In applying CBwaves various physically interesting scenarios have been investigated. In particular, we have studied the appropriateness of the adiabatic approximation, and justified that the energy balance relation is indeed insensitive to the specific form of the applied radiation reaction term. By studying eccentric binary systems, it is demonstrated that circular template banks are very ineffective in identifying binaries even if they possess tiny residual orbital eccentricity, thus confirming a similar result obtained by Brown and Zimmerman (2010 Phys. Rev. D 81 024007). In addition, by investigating the validity of the energy balance relation we show that, contrary to the general expectations, the PN approximation should not be applied once the PN parameter gets beyond the critical value ˜0.08 - 0.1. Finally, by studying the early phase of the gravitational waves emitted by strongly eccentric binary systems—which could be formed e.g. in various many-body interactions in the galactic halo—we have found that they possess very specific characteristics which may be used to identify these type of binary systems. This paper is dedicated to the memory of our colleague and friend Péter Csizmadia a young physicist, computer expert and one of the best Hungarian mountaineers who disappeared in China’s Sichuan near the Ren Zhong Feng peak of the Himalayas on 23 Oct. 2009. We started to develop CBwaves jointly with Péter a couple of months before he left for China.

  1. Probabilistic seismic history matching using binary images

    Science.gov (United States)

    Davolio, Alessandra; Schiozer, Denis Jose

    2018-02-01

    Currently, the goal of history-matching procedures is not only to provide a model matching any observed data but also to generate multiple matched models to properly handle uncertainties. One such approach is a probabilistic history-matching methodology based on the discrete Latin Hypercube sampling algorithm, proposed in previous works, which was particularly efficient for matching well data (production rates and pressure). 4D seismic (4DS) data have been increasingly included into history-matching procedures. A key issue in seismic history matching (SHM) is to transfer data into a common domain: impedance, amplitude or pressure, and saturation. In any case, seismic inversions and/or modeling are required, which can be time consuming. An alternative to avoid these procedures is using binary images in SHM as they allow the shape, rather than the physical values, of observed anomalies to be matched. This work presents the incorporation of binary images in SHM within the aforementioned probabilistic history matching. The application was performed with real data from a segment of the Norne benchmark case that presents strong 4D anomalies, including softening signals due to pressure build up. The binary images are used to match the pressurized zones observed in time-lapse data. Three history matchings were conducted using: only well data, well and 4DS data, and only 4DS. The methodology is very flexible and successfully utilized the addition of binary images for seismic objective functions. Results proved the good convergence of the method in few iterations for all three cases. The matched models of the first two cases provided the best results, with similar well matching quality. The second case provided models presenting pore pressure changes according to the expected dynamic behavior (pressurized zones) observed on 4DS data. The use of binary images in SHM is relatively new with few examples in the literature. This work enriches this discussion by presenting a new

  2. Rapid method for interconversion of binary and decimal numbers

    Science.gov (United States)

    Lim, R. S.

    1970-01-01

    Decoding tree consisting of 40-bit semiconductor read-only memories interconverts binary and decimal numbers 50 to 100 times faster than current methods. Decimal-to-binary conversion algorithm is based on a divided-by-2 iterative equation, binary-to-decimal conversion algorithm utilizes multiplied-by-2 iterative equation.

  3. Binary interaction dominates the evolution of massive stars

    NARCIS (Netherlands)

    Sana, H.; de Mink, S.E.; de Koter, A.; Langer, N.; Evans, C.J.; Gieles, M.; Gosset, E.; Izzard, R.G.; Le Bouquin, J.-B.; Schneider, F.R.N.

    2012-01-01

    The presence of a nearby companion alters the evolution of massive stars in binary systems, leading to phenomena such as stellar mergers, x-ray binaries, and gamma-ray bursts. Unambiguous constraints on the fraction of massive stars affected by binary interaction were lacking. We simultaneously

  4. Microlensing Binaries Discovered through High-magnification Channel

    DEFF Research Database (Denmark)

    Shin, I.-G.; Choi, J.-Y.; Park, S.-Y.

    2012-01-01

    Microlensing can provide a useful tool to probe binary distributions down to low-mass limits of binary companions. In this paper, we analyze the light curves of eight binary-lensing events detected through the channel of high-magnification events during the seasons from 2007 to 2010. The perturba...

  5. Compact stars and the evolution of binary systems

    NARCIS (Netherlands)

    van den Heuvel, E.P.J.

    2011-01-01

    The Chandrasekhar limit is of key importance for the evolution of white dwarfs in binary systems and for the formation of neutron stars and black holes in binaries. Mass transfer can drive a white dwarf in a binary over the Chandrasekhar limit, which may lead to a Type Ia supernova (in case of a CO

  6. A decoding method of an n length binary BCH code through (n + 1n length binary cyclic code

    Directory of Open Access Journals (Sweden)

    TARIQ SHAH

    2013-09-01

    Full Text Available For a given binary BCH code Cn of length n = 2 s - 1 generated by a polynomial of degree r there is no binary BCH code of length (n + 1n generated by a generalized polynomial of degree 2r. However, it does exist a binary cyclic code C (n+1n of length (n + 1n such that the binary BCH code Cn is embedded in C (n+1n . Accordingly a high code rate is attained through a binary cyclic code C (n+1n for a binary BCH code Cn . Furthermore, an algorithm proposed facilitates in a decoding of a binary BCH code Cn through the decoding of a binary cyclic code C (n+1n , while the codes Cn and C (n+1n have the same minimum hamming distance.

  7. Experimental study on thermal storage performance of binary mixtures of fatty acids

    Science.gov (United States)

    Yan, Quanying; Zhang, Jing; Liu, Chao; Liu, Sha; Sun, Xiangyu

    2018-02-01

    We selected five kinds of fatty acids including the capric acid, stearic acid, lauric acid, palmitic acid and myristic acid and mixed them to prepare10 kinds of binary mixtures of fatty acids according to the predetermined proportion,tested the phase change temperature and latent heat of mixtures by differential scanning calorimetry(DSC). In order to find the fatty acid mixture which has suitable phase change temperature, the larger phase change latent heat and can be used for phase change wall. The results showed that the phase change temperature and latent heats of the binary mixtures of fatty acids decreased compared with the single component;The phase change temperature of the binary mixtures of fatty acids containing capric acid were lower, the range was roughly 20∼30°C,and latent heat is large,which are ideal phase change materials for phase change wall energy storage;The phase change temperature of the binary mixtures consisting of other fatty acids were still high,didn’t meet the temperature requirements of the wall energy storage.

  8. Electrostatic and capillary force directed tunable 3D binary micro- and nanoparticle assemblies on surfaces

    International Nuclear Information System (INIS)

    Singh, G; Pillai, S; Arpanaei, A; Kingshott, P

    2011-01-01

    We report a simple, rapid and cost-effective method based on evaporation induced assembly to grow 3D binary colloidal assemblies on a hydrophobic/hydrophilic substrate by simple drop casting. The evaporation of a mixed colloidal drop results in ring-like or uniform area deposition depending on the concentration of particles, and thus assembly occurs at the periphery of a ring or uniformly all over the drop area. Binary colloidal assemblies of different crystal structure are successfully prepared over a wide range of size ratios (γ = small/large) from 0.06 to 0.30 by tuning the γ of the micro- and nanoparticles used during assembly. The growth mechanism of 3D binary colloidal assemblies is investigated and it is found that electrostatic forces facilitate assembly formation until the end of the evaporation process, with capillary forces also playing a role. In addition, the effects of solvent type, humidity, and salt concentration on crystal formation and ordering behaviour are also examined. Furthermore, long range, highly ordered binary colloidal assemblies can be fabricated by the choice of a low conducting solvent combined with evaporation induced assembly.

  9. Growth of TiO2-ZrO2 Binary Oxide Electrode for Dye Sensitized Solar Cell Application

    International Nuclear Information System (INIS)

    Than Than Win; Aye Myint Myat Kywe; Shwe Yee Win; Honey Thaw; Yin Maung Maung; Ko Ko Kyaw Soe

    2011-12-01

    TiO2-ZrO2 fine binary oxide was prepared by mechanochemical milling process to be homogeneous binary oxide powder. TiO2-ZrO2 paste was deposited on microscopic glass slide by rolling. It was immersed in the henna solution and annealed at 100C for 2h. It was deposited onto another glass slide and used as counter electrode (second electrode). Two glass slides were offset and two binder clips were used to hold the electrodes together. Photovoltaic properties of TiO2-ZrO2 cell were measured and it was expected to utilize the dye sensitized solar cells application.

  10. Sample preparation

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    Sample preparation prior to HPLC analysis is certainly one of the most important steps to consider in trace or ultratrace analysis. For many years scientists have tried to simplify the sample preparation process. It is rarely possible to inject a neat liquid sample or a sample where preparation may not be any more complex than dissolution of the sample in a given solvent. The last process alone can remove insoluble materials, which is especially helpful with the samples in complex matrices if other interactions do not affect extraction. Here, it is very likely a large number of components will not dissolve and are, therefore, eliminated by a simple filtration process. In most cases, the process of sample preparation is not as simple as dissolution of the component interest. At times, enrichment is necessary, that is, the component of interest is present in very large volume or mass of material. It needs to be concentrated in some manner so a small volume of the concentrated or enriched sample can be injected into HPLC. 88 refs

  11. Confusing Binaries: The Role of Stellar Binaries in Biasing Disk Properties in the Galactic Center

    Science.gov (United States)

    Naoz, Smadar; Ghez, Andrea M.; Hees, Aurelien; Do, Tuan; Witzel, Gunther; Lu, Jessica R.

    2018-02-01

    The population of young stars near the supermassive black hole (SMBH) in the Galactic Center (GC) has presented an unexpected challenge to theories of star formation. Kinematic measurements of these stars have revealed a stellar disk structure (with an apparent 20% disk membership) that has provided important clues regarding the origin of these mysterious young stars. However, many of the apparent disk properties are difficult to explain, including the low disk membership fraction and the high eccentricities given the youth of this population. Thus far, all efforts to derive the properties of this disk have made the simplifying assumption that stars at the GC are single stars. Nevertheless, stellar binaries are prevalent in our Galaxy, and recent investigations suggested that they may also be abundant in the Galactic Center. Here, we show that binaries in the disk can largely alter the apparent orbital properties of the disk. The motion of binary members around each other adds a velocity component, which can be comparable to the magnitude of the velocity around the SMBH in the GC. Thus, neglecting the contribution of binaries can significantly vary the inferred stars’ orbital properties. While the disk orientation is unaffected, the apparent disk’s 2D width will be increased to about 11.°2, similar to the observed width. For a population of stars orbiting the SMBH with zero eccentricity, unaccounted for binaries will create a wide apparent eccentricity distribution with an average of 0.23. This is consistent with the observed average eccentricity of the stars’ in the disk. We suggest that this high eccentricity value, which poses a theoretical challenge, may be an artifact of binary stars. Finally, our results suggest that the actual disk membership might be significantly higher than the one inferred by observations that ignore the contribution of binaries, alleviating another theoretical challenge.

  12. Performance analysis and binary working fluid selection of combined flash-binary geothermal cycle

    International Nuclear Information System (INIS)

    Zeyghami, Mehdi

    2015-01-01

    Performance of the combined flash-binary geothermal power cycle for geofluid temperatures between 150 and 250 °C is studied. A thermodynamic model is developed, and the suitable binary working fluids for different geofluid temperatures are identified from a list of thirty working fluid candidates, consisting environmental friendly refrigerants and hydrocarbons. The overall system exergy destruction and Vapor Expansion Ratio across the binary cycle turbine are selected as key performance indicators. The results show that for low-temperature heat sources using refrigerants as binary working fluids result in higher overall cycle efficiency and for medium and high-temperature resources, hydrocarbons are more suitable. For combined flash-binary cycle, secondary working fluids; R-152a, Butane and Cis-butane show the best performances at geofluid temperatures 150, 200 and 250 °C respectively. The overall second law efficiency is calculated as high as 0.48, 0.55 and 0.58 for geofluid temperatures equal 150, 200 and 250 °C respectively. The flash separator pressure found to has important effects on cycle operation and performance. Separator pressure dictates the work production share of steam and binary parts of the system. And there is an optimal separator pressure at which overall exergy destruction of the cycle achieves its minimum value. - Highlights: • Performance of the combined flash-binary geothermal cycle is investigated. • Thirty different fluids are screened to find the most suitable ORC working fluid. • Optimum cycle operation conditions presented for geofluids between 150 °C and 250 °C. • Refrigerants are more suitable for the ORC at geothermal sources temperature ≤200 °C. • Hydrocarbons are more suitable for the ORC at geothermal sources temperature >200 °C

  13. Complex Binary Number System Algorithms and Circuits

    CERN Document Server

    Jamil, Tariq

    2013-01-01

    This book is a compilation of the entire research work on the topic of Complex Binary Number System (CBNS) carried out by the author as the principal investigator and members of his research groups at various universities during the years 1992-2012. Pursuant to these efforts spanning several years, the realization of CBNS as a viable alternative to represent complex numbers in an 'all-in-one' binary number format has become possible and efforts are underway to build computer hardware based on this unique number system. It is hoped that this work will be of interest to anyone involved in computer arithmetic and digital logic design and kindle renewed enthusiasm among the engineers working in the areas of digital signal and image processing for developing newer and efficient algorithms and techniques incorporating CBNS.

  14. Studies of Long Period Eclipsing Binaries

    Science.gov (United States)

    Ratajczak, M.; Hełminiak, K. G.; Konacki, M.

    2015-07-01

    The survey of long period eclipsing binaries from the All Sky Automated Survey (ASAS) catalog aims at searching for and characterizing subgiants and red giants in double-lined detached binary systems. Absolute physical and orbital parameters are presented based on radial velocities from high-quality optical spectra obtained with the following telescope/instrument combinations: 8.2 m Subaru/HDS, ESO 3.6 m/HARPS, 1.9 m Radcliffe/GIRAFFE, CTIO 1.5 m/CHIRON, and 1.2 m Euler/CORALIE. Photometric data from ASAS, SuperWASP, and the Solaris Project were also used. We discuss the derived uncertainties for the individual masses and radii of the components (better than 3% for several systems), as well as results from the spectral analysis performed for components of systems whose spectra we disentangled.

  15. Kilonova Counterparts of Binary Neutron Star Mergers

    Science.gov (United States)

    Metzger, Brian

    2018-01-01

    The merger of a binary neutron star is accompanied by the ejection of neutron-rich matter into space at velocities up to several tenths that of light, which synthesizes rare heavy isotopes through the rapid neutron capture process (r-process). The radioactive decay of these nuclei was predicted by Metzger et al. (2010) to power an optical transient roughly 1000 times more luminous than a classical nova (a "kilonova"), which is among the most promising electromagnetic counterparts to accompany gravitational wave signal from the merger. I will describe how the luminosities, color, and spectra of the kilonova emission inform the properties of the merging binary (neutron star masses/radii and inclination angle) and the long sought origin of the heaviest elements in the Universe. Results will be discussed in the context of recent discoveries by Advanced LIGO/Virgo.

  16. On the dynamics of binary galaxies

    International Nuclear Information System (INIS)

    Verner, D.A.; Chernin, A.D.

    1987-01-01

    The dynamics of close noncontact binary galaxies is investigated. It is demonsrated that the tidal interaction is ineffective for circularization of galaxy orbits. Nonsphericity of galaxies develops a torque in a binary system. For a pair of elliptical galaxies this torque leads to swinging of the galaxies with respect to the orbital plane (which can be observed as a rotation about the minor axis) and to the excitation of internal degrees of freedom. Besides, this pendulum effect may be effective for elliptical galaxies in clusters due to the presence of the torque produced by a cluster as a whole. In the case of spiral galaxies the torque leads to the precession of their rotational axes. However this effect seems to be too weak to be observable

  17. Induced Ellipticity for Inspiraling Binary Systems

    Science.gov (United States)

    Randall, Lisa; Xianyu, Zhong-Zhi

    2018-01-01

    Although gravitational waves tend to erase eccentricity of an inspiraling binary system, ellipticity can be generated in the presence of surrounding matter. We present a semianalytical method for understanding the eccentricity distribution of binary black holes (BHs) in the presence of a supermassive BH in a galactic center. Given a matter distribution, we show how to determine the resultant eccentricity analytically in the presence of both tidal forces and evaporation up to one cutoff and one matter-distribution-independent function, paving the way for understanding the environment of detected inspiraling BHs. We furthermore generalize Kozai–Lidov dynamics to situations where perturbation theory breaks down for short time intervals, allowing more general angular momentum exchange, such that eccentricity is generated even when all bodies orbit in the same plane.

  18. Binary fingerprints at fluctuation-enhanced sensing.

    Science.gov (United States)

    Chang, Hung-Chih; Kish, Laszlo B; King, Maria D; Kwan, Chiman

    2010-01-01

    We have developed a simple way to generate binary patterns based on spectral slopes in different frequency ranges at fluctuation-enhanced sensing. Such patterns can be considered as binary "fingerprints" of odors. The method has experimentally been demonstrated with a commercial semiconducting metal oxide (Taguchi) sensor exposed to bacterial odors (Escherichia coli and Anthrax-surrogate Bacillus subtilis) and processing their stochastic signals. With a single Taguchi sensor, the situations of empty chamber, tryptic soy agar (TSA) medium, or TSA with bacteria could be distinguished with 100% reproducibility. The bacterium numbers were in the range of 2.5 × 10(4)-10(6). To illustrate the relevance for ultra-low power consumption, we show that this new type of signal processing and pattern recognition task can be implemented by a simple analog circuitry and a few logic gates with total power consumption in the microWatts range.

  19. X-Ray Background from Early Binaries

    Science.gov (United States)

    Kohler, Susanna

    2016-11-01

    What impact did X-rays from the first binary star systems have on the universe around them? A new study suggests this radiation may have played an important role during the reionization of our universe.Ionizing the UniverseDuring the period of reionization, the universe reverted from being neutral (as it was during recombination, the previous period)to once again being ionized plasma a state it has remained in since then. This transition, which occurred between 150 million and one billion years after the Big Bang (redshift of 6 z 20), was caused by the formation of the first objects energetic enough to reionize the universes neutral hydrogen.ROSAT image of the soft X-ray background throughout the universe. The different colors represent different energy bands: 0.25 keV (red), 0.75 keV (green), 1.5 keV (blue). [NASA/ROSAT Project]Understanding this time period in particular, determining what sources caused the reionization, and what the properties were of the gas strewn throughout the universe during this time is necessary for us to be able to correctly interpret cosmological observations.Conveniently, the universe has provided us with an interesting clue: the large-scale, diffuse X-ray background we observe all around us. What produced these X-rays, and what impact did this radiation have on the intergalactic medium long ago?The First BinariesA team of scientists led by Hao Xu (UC San Diego) has suggested that the very first generation of stars might be an important contributor to these X-rays.This hypothetical first generation, Population III stars, are thought to have formed before and during reionization from large clouds of gas containing virtually no metals. Studies suggest that a large fraction of Pop III stars formed in binaries and when those stars ended their lives as black holes, ensuing accretion from their companions could produceX-ray radiation.The evolution with redshift of the mean X-ray background intensities. Each curve represents a different

  20. Eclipsing binary stars modeling and analysis

    CERN Document Server

    Kallrath, Josef

    1999-01-01

    This book focuses on the formulation of mathematical models for the light curves of eclipsing binary stars, and on the algorithms for generating such models Since information gained from binary systems provides much of what we know of the masses, luminosities, and radii of stars, such models are acquiring increasing importance in studies of stellar structure and evolution As in other areas of science, the computer revolution has given many astronomers tools that previously only specialists could use; anyone with access to a set of data can now expect to be able to model it This book will provide astronomers, both amateur and professional, with a guide for - specifying an astrophysical model for a set of observations - selecting an algorithm to determine the parameters of the model - estimating the errors of the parameters It is written for readers with knowledge of basic calculus and linear algebra; appendices cover mathematical details on such matters as optimization, coordinate systems, and specific models ...

  1. Binary interaction dominates the evolution of massive stars.

    Science.gov (United States)

    Sana, H; de Mink, S E; de Koter, A; Langer, N; Evans, C J; Gieles, M; Gosset, E; Izzard, R G; Le Bouquin, J-B; Schneider, F R N

    2012-07-27

    The presence of a nearby companion alters the evolution of massive stars in binary systems, leading to phenomena such as stellar mergers, x-ray binaries, and gamma-ray bursts. Unambiguous constraints on the fraction of massive stars affected by binary interaction were lacking. We simultaneously measured all relevant binary characteristics in a sample of Galactic massive O stars and quantified the frequency and nature of binary interactions. More than 70% of all massive stars will exchange mass with a companion, leading to a binary merger in one-third of the cases. These numbers greatly exceed previous estimates and imply that binary interaction dominates the evolution of massive stars, with implications for populations of massive stars and their supernovae.

  2. Detectability of Gravitational Waves from High-Redshift Binaries.

    Science.gov (United States)

    Rosado, Pablo A; Lasky, Paul D; Thrane, Eric; Zhu, Xingjiang; Mandel, Ilya; Sesana, Alberto

    2016-03-11

    Recent nondetection of gravitational-wave backgrounds from pulsar timing arrays casts further uncertainty on the evolution of supermassive black hole binaries. We study the capabilities of current gravitational-wave observatories to detect individual binaries and demonstrate that, contrary to conventional wisdom, some are, in principle, detectable throughout the Universe. In particular, a binary with rest-frame mass ≳10^{10}M_{⊙} can be detected by current timing arrays at arbitrarily high redshifts. The same claim will apply for less massive binaries with more sensitive future arrays. As a consequence, future searches for nanohertz gravitational waves could be expanded to target evolving high-redshift binaries. We calculate the maximum distance at which binaries can be observed with pulsar timing arrays and other detectors, properly accounting for redshift and using realistic binary waveforms.

  3. THE ELM SURVEY. V. MERGING MASSIVE WHITE DWARF BINARIES

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Warren R.; Kenyon, Scott J. [Smithsonian Astrophysical Observatory, 60 Garden St, Cambridge, MA 02138 (United States); Kilic, Mukremin; Gianninas, A. [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, 440 W. Brooks St., Norman, OK, 73019 (United States); Allende Prieto, Carlos, E-mail: wbrown@cfa.harvard.edu, E-mail: skenyon@cfa.harvard.edu, E-mail: kilic@ou.edu, E-mail: alexg@nhn.ou.edu, E-mail: callende@iac.es [Instituto de Astrofisica de Canarias, E-38205, La Laguna, Tenerife (Spain)

    2013-05-20

    We present the discovery of 17 low-mass white dwarfs (WDs) in short-period (P {<=} 1 day) binaries. Our sample includes four objects with remarkable log g {approx_equal} 5 surface gravities and orbital solutions that require them to be double degenerate binaries. All of the lowest surface gravity WDs have metal lines in their spectra implying long gravitational settling times or ongoing accretion. Notably, six of the WDs in our sample have binary merger times <10 Gyr. Four have {approx}>0.9 M{sub Sun} companions. If the companions are massive WDs, these four binaries will evolve into stable mass transfer AM CVn systems and possibly explode as underluminous supernovae. If the companions are neutron stars, then these may be millisecond pulsar binaries. These discoveries increase the number of detached, double degenerate binaries in the ELM Survey to 54; 31 of these binaries will merge within a Hubble time.

  4. THE ELM SURVEY. V. MERGING MASSIVE WHITE DWARF BINARIES

    International Nuclear Information System (INIS)

    Brown, Warren R.; Kenyon, Scott J.; Kilic, Mukremin; Gianninas, A.; Allende Prieto, Carlos

    2013-01-01

    We present the discovery of 17 low-mass white dwarfs (WDs) in short-period (P ≤ 1 day) binaries. Our sample includes four objects with remarkable log g ≅ 5 surface gravities and orbital solutions that require them to be double degenerate binaries. All of the lowest surface gravity WDs have metal lines in their spectra implying long gravitational settling times or ongoing accretion. Notably, six of the WDs in our sample have binary merger times 0.9 M ☉ companions. If the companions are massive WDs, these four binaries will evolve into stable mass transfer AM CVn systems and possibly explode as underluminous supernovae. If the companions are neutron stars, then these may be millisecond pulsar binaries. These discoveries increase the number of detached, double degenerate binaries in the ELM Survey to 54; 31 of these binaries will merge within a Hubble time.

  5. White dwarfs in Be star binary systems

    Science.gov (United States)

    Apparao, K. M. V.

    1991-01-01

    An evaluation is made of possible reasons for the persistent inability to identify white dwarf stars in the Be binary systems. It is noted that many Be stars exhibiting large optical enhancements may be Be + WD and Be + He systems, and that observations of pulsations in the H-alpha emission, as well as observation of time delays between enhancements of optical line and continuum, can identify such systems.

  6. Search for forced oscillations in binaries

    Czech Academy of Sciences Publication Activity Database

    Janík, J.; Harmanec, Petr; Lehmann, H.; Yang, S.; Božić, H.; Ak, H.; Hadrava, Petr; Eenens, P.; Ruždjak, D.; Sudar, D.; Hubený, I.; Linnell, A. P.

    2003-01-01

    Roč. 408, č. 2 (2003), s. 611-619 ISSN 0004-6361 R&D Projects: GA ČR GA205/96/0162; GA ČR GA205/02/0445; GA AV ČR IAA3003805; GA AV ČR KSK2043105 Institutional research plan: CEZ:AV0Z1003909 Keywords : binaries stars * close stars * spectroscopis Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 3.843, year: 2003

  7. Binary choice models with endogenous regressors

    OpenAIRE

    Christopher Baum; Yingying Dong; Arthur Lewbel; Tao Yang

    2012-01-01

    Dong and Lewbel have developed the theory of simple estimators for binary choice models with endogenous or mismeasured regressors, depending on a `special regressor' as defined by Lewbel (J. Econometrics, 2000). `Control function' methods such as Stata's ivprobit are generally only valid when endogenous regressors are consistent. The estimators proposed here can be used with limited, censored, continuous or discrete endogenous regressors, and have significant advantages over alternatives such...

  8. Digitizing Villanova University's Eclipsing Binary Card Catalogue

    Science.gov (United States)

    Guzman, Giannina; Dalton, Briana; Conroy, Kyle; Prsa, Andrej

    2018-01-01

    Villanova University’s Department of Astrophysics and Planetary Science has years of hand-written archival data on Eclipsing Binaries at its disposal. This card catalog began at Princeton in the 1930’s with notable contributions from scientists such as Henry Norris Russel. During World War II, the archive was moved to the University of Pennsylvania, which was one of the world centers for Eclipsing Binary research, consequently, the contributions to the catalog during this time were immense. It was then moved to University of Florida at Gainesville before being accepted by Villanova in the 1990’s. The catalog has been kept in storage since then. The objective of this project is to digitize this archive and create a fully functional online catalog that contains the information available on the cards, along with the scan of the actual cards. Our group has built a database using a python-powered infrastructure to contain the collected data. The team also built a prototype web-based searchable interface as a front-end to the catalog. Following the data-entry process, information like the Right Ascension and Declination will be run against SIMBAD and any differences between values will be noted as part of the catalog. Information published online from the card catalog and even discrepancies in information for a star, could be a catalyst for new studies on these Eclipsing Binaries. Once completed, the database-driven interface will be made available to astronomers worldwide. The group will also acquire, from the database, a list of referenced articles that have yet to be found online in order to further pursue their digitization. This list will be comprised of references in the cards that were neither found on ADS nor online during the data-entry process. Pursuing the integration of these references to online queries such as ADS will be an ongoing process that will contribute and further facilitate studies on Eclipsing Binaries.

  9. Phase analysis of amplitude binary mask structures

    Science.gov (United States)

    Puthankovilakam, Krishnaparvathy; Scharf, Toralf; Herzig, Hans Peter; Vogler, Uwe; Bramati, Arianna; Voelkel, Reinhard

    2016-03-01

    Shaping of light behind masks using different techniques is the milestone of the printing industry. The aerial image distribution or the intensity distribution at the printing distances defines the resolution of the structure after printing. Contrast and phase are the two parameters that play a major role in shaping of light to get the desired intensity pattern. Here, in contrast to many other contributions that focus on intensity, we discuss the phase evolution for different structures. The amplitude or intensity characteristics of the structures in a binary mask at different proximity gaps have been analyzed extensively for many industrial applications. But the phase evolution from the binary mask having OPC structures is not considered so far. The mask we consider here is the normal amplitude binary mask but having high resolution Optical Proximity Correction (OPC) structures for corners. The corner structures represent a two dimensional problem which is difficult to handle with simple rules of phase masks design and therefore of particular interest. The evolution of light from small amplitude structures might lead to high contrast by creating sharp phase changes or phase singularities which are points of zero intensity. We show the phase modulation at different proximity gaps and can visualize the shaping of light according to the phase changes. The analysis is done with an instrument called High Resolution Interference Microscopy (HRIM), a Mach-Zehnder interferometer that gives access to three-dimensional phase and amplitude images. The current paper emphasizes on the phase measurement of different optical proximity correction structures, and especially on corners of a binary mask.

  10. Composition profile determination in isomorphous binary alloys

    International Nuclear Information System (INIS)

    An, C.Y.; Bandeira, I.N.

    1983-07-01

    The inhomogeneity along the growth axis of the pseudo-binary alloys is due to the segregation of the solute which will be mixed in the melt due to convective and diffusive flows. A process for determination of the exact composition profile by measurements of the crystal density, for alloys of the type A sub(1-x) B sub(x), is shown. (Author) [pt

  11. Robust Speech Recognition from Binary Masks

    Science.gov (United States)

    2010-01-01

    invariance to translation and size of the input pattern. Since the binary patterns of IBM are, in a way, similar to handwritten digits, we used a CNN...classification for each pattern. This also adds to the translational invariance of the CNN. To be consistent, we use the same strategy while testing IBMs...the cases, the noisy speech was enhanced using the MMSE algorithm, which is a widely used speech enhancement algorithm (Ephraim and Malah, 1985), as

  12. Inducing Risk Neutral Preferences with Binary Lotteries

    DEFF Research Database (Denmark)

    Harrison, Glenn W.; Martínez-Correa, Jimmy; Swarthout, J. Todd

    2013-01-01

    We evaluate the binary lottery procedure for inducing risk neutral behavior. We strip the experimental implementation down to bare bones, taking care to avoid any potentially confounding assumptions about behavior having to be made. In particular, our evaluation does not rely on the assumed valid...... toward risk neutrality. This striking result generalizes to the case in which subjects make several lottery choices and one is selected for payment....

  13. Binary DNA Nanostructures for Data Encryption

    OpenAIRE

    Halvorsen, Ken; Wong, Wesley P.

    2012-01-01

    We present a simple and secure system for encrypting and decrypting information using DNA self-assembly. Binary data is encoded in the geometry of DNA nanostructures with two distinct conformations. Removing or leaving out a single component reduces these structures to an encrypted solution of ssDNA, whereas adding back this missing "decryption key" causes the spontaneous formation of the message through self-assembly, enabling rapid read out via gel electrophoresis. Applications include auth...

  14. Binary DNA nanostructures for data encryption.

    Science.gov (United States)

    Halvorsen, Ken; Wong, Wesley P

    2012-01-01

    We present a simple and secure system for encrypting and decrypting information using DNA self-assembly. Binary data is encoded in the geometry of DNA nanostructures with two distinct conformations. Removing or leaving out a single component reduces these structures to an encrypted solution of ssDNA, whereas adding back this missing "decryption key" causes the spontaneous formation of the message through self-assembly, enabling rapid read out via gel electrophoresis. Applications include authentication, secure messaging, and barcoding.

  15. EXACT LOGISTIC MODELS FOR NESTED BINARY DATA

    OpenAIRE

    TROXLER, STEVEN; LALONDE, TRENT; WILSON, JEFFREY R.

    2011-01-01

    The use of logistic models for independent binary data has relied first on asymptotic theory and later on exact distributions for small samples. However, the use of logistic models for dependent analysis based on exact analysis is not as common. Moreover attention is usually given to one-stage clustering. In this paper we extend the exact techniques to address hypothesis testing (estimation is not addressed) for data with second-stage and probably higher levels of clustering. The methods are ...

  16. Relativistic apsidal motion in eccentric eclipsing binaries

    Czech Academy of Sciences Publication Activity Database

    Wolf, M.; Claret, L.; Kotková, Lenka; Kučáková, Hana; Kocián, R.; Brát, L.; Svoboda, P.; Šmelcer, L.

    2010-01-01

    Roč. 509, January (2010), A18/1-A18/14 ISSN 0004-6361 Grant - others:GA ČR(CZ) GA205/04/2063; GA ČR(CZ) GA205/06/0217 Institutional research plan: CEZ:AV0Z10030501 Keywords : binaries eclipsing Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 4.410, year: 2010

  17. Orbital Decay in Binaries with Evolved Stars

    Science.gov (United States)

    Sun, Meng; Arras, Phil; Weinberg, Nevin N.; Troup, Nicholas; Majewski, Steven R.

    2018-01-01

    Two mechanisms are often invoked to explain tidal friction in binary systems. The ``dynamical tide” is the resonant excitation of internal gravity waves by the tide, and their subsequent damping by nonlinear fluid processes or thermal diffusion. The ``equilibrium tide” refers to non-resonant excitation of fluid motion in the star’s convection zone, with damping by interaction with the turbulent eddies. There have been numerous studies of these processes in main sequence stars, but less so on the subgiant and red giant branches. Motivated by the newly discovered close binary systems in the Apache Point Observatory Galactic Evolution Experiment (APOGEE-1), we have performed calculations of both the dynamical and equilibrium tide processes for stars over a range of mass as the star’s cease core hydrogen burning and evolve to shell burning. Even for stars which had a radiative core on the main sequence, the dynamical tide may have very large amplitude in the newly radiative core in post-main sequence, giving rise to wave breaking. The resulting large dynamical tide dissipation rate is compared to the equilibrium tide, and the range of secondary masses and orbital periods over which rapid orbital decay may occur will be discussed, as well as applications to close APOGEE binaries.

  18. Spinodal decomposition of chemically reactive binary mixtures

    Science.gov (United States)

    Lamorgese, A.; Mauri, R.

    2016-08-01

    We simulate the influence of a reversible isomerization reaction on the phase segregation process occurring after spinodal decomposition of a deeply quenched regular binary mixture, restricting attention to systems wherein material transport occurs solely by diffusion. Our theoretical approach follows a diffuse-interface model of partially miscible binary mixtures wherein the coupling between reaction and diffusion is addressed within the frame of nonequilibrium thermodynamics, leading to a linear dependence of the reaction rate on the chemical affinity. Ultimately, the rate for an elementary reaction depends on the local part of the chemical potential difference since reaction is an inherently local phenomenon. Based on two-dimensional simulation results, we express the competition between segregation and reaction as a function of the Damköhler number. For a phase-separating mixture with components having different physical properties, a skewed phase diagram leads, at large times, to a system converging to a single-phase equilibrium state, corresponding to the absolute minimum of the Gibbs free energy. This conclusion continues to hold for the critical phase separation of an ideally perfectly symmetric binary mixture, where the choice of final equilibrium state at large times depends on the initial mean concentration being slightly larger or less than the critical concentration.

  19. Circumstellar disks around binary stars in Taurus

    International Nuclear Information System (INIS)

    Akeson, R. L.; Jensen, E. L. N.

    2014-01-01

    We have conducted a survey of 17 wide (>100 AU) young binary systems in Taurus with the Atacama Large Millimeter Array (ALMA) at two wavelengths. The observations were designed to measure the masses of circumstellar disks in these systems as an aid to understanding the role of multiplicity in star and planet formation. The ALMA observations had sufficient resolution to localize emission within the binary system. Disk emission was detected around all primaries and 10 secondaries, with disk masses as low as 10 –4 M ☉ . We compare the properties of our sample to the population of known disks in Taurus and find that the disks from this binary sample match the scaling between stellar mass and millimeter flux of F mm ∝M ∗ 1.5--2.0 to within the scatter found in previous studies. We also compare the properties of the primaries to those of the secondaries and find that the secondary/primary stellar and disk mass ratios are not correlated; in three systems, the circumsecondary disk is more massive than the circumprimary disk, counter to some theoretical predictions.

  20. Circumstellar disks around binary stars in Taurus

    Energy Technology Data Exchange (ETDEWEB)

    Akeson, R. L. [NASA Exoplanet Science Institute, IPAC/Caltech, Pasadena, CA 91125 (United States); Jensen, E. L. N. [Swarthmore College, Department of Physics and Astronomy, Swarthmore, PA 19081 (United States)

    2014-03-20

    We have conducted a survey of 17 wide (>100 AU) young binary systems in Taurus with the Atacama Large Millimeter Array (ALMA) at two wavelengths. The observations were designed to measure the masses of circumstellar disks in these systems as an aid to understanding the role of multiplicity in star and planet formation. The ALMA observations had sufficient resolution to localize emission within the binary system. Disk emission was detected around all primaries and 10 secondaries, with disk masses as low as 10{sup –4} M {sub ☉}. We compare the properties of our sample to the population of known disks in Taurus and find that the disks from this binary sample match the scaling between stellar mass and millimeter flux of F{sub mm}∝M{sub ∗}{sup 1.5--2.0} to within the scatter found in previous studies. We also compare the properties of the primaries to those of the secondaries and find that the secondary/primary stellar and disk mass ratios are not correlated; in three systems, the circumsecondary disk is more massive than the circumprimary disk, counter to some theoretical predictions.

  1. ORBITAL EVOLUTION OF COMPACT WHITE DWARF BINARIES

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, David L. [Physics Department, University of Wisconsin-Milwaukee, Milwaukee, WI 53211 (United States); Bildsten, Lars [Kavli Institute for Theoretical Physics and Department of Physics, Kohn Hall, University of California, Santa Barbara, CA 93106 (United States); Steinfadt, Justin D. R., E-mail: kaplan@uwm.edu, E-mail: bildsten@kitp.ucsb.edu, E-mail: jdrsteinfadt@gmail.com [Department of Physics, Broida Hall, University of California, Santa Barbara, CA 93106 (United States)

    2012-10-10

    The newfound prevalence of extremely low mass (ELM, M{sub He} < 0.2 M{sub Sun }) helium white dwarfs (WDs) in tight binaries with more massive WDs has raised our interest in understanding the nature of their mass transfer. Possessing small (M{sub env} {approx} 10{sup -3} M{sub Sun }) but thick hydrogen envelopes, these objects have larger radii than cold WDs and so initiate mass transfer of H-rich material at orbital periods of 6-10 minutes. Building on the original work of D'Antona et al., we confirm the 10{sup 6} yr period of continued inspiral with mass transfer of H-rich matter and highlight the fact that the inspiraling direct-impact double WD binary HM Cancri likely has an ELM WD donor. The ELM WDs have less of a radius expansion under mass loss, thus enabling a larger range of donor masses that can stably transfer matter and become a He mass transferring AM CVn binary. Even once in the long-lived AM CVn mass transferring stage, these He WDs have larger radii due to their higher entropy from the prolonged H-burning stage.

  2. Constraining the Statistics of Population III Binaries

    Science.gov (United States)

    Stacy, Athena; Bromm, Volker

    2012-01-01

    We perform a cosmological simulation in order to model the growth and evolution of Population III (Pop III) stellar systems in a range of host minihalo environments. A Pop III multiple system forms in each of the ten minihaloes, and the overall mass function is top-heavy compared to the currently observed initial mass function in the Milky Way. Using a sink particle to represent each growing protostar, we examine the binary characteristics of the multiple systems, resolving orbits on scales as small as 20 AU. We find a binary fraction of approx. 36, with semi-major axes as large as 3000 AU. The distribution of orbital periods is slightly peaked at approx. < 900 yr, while the distribution of mass ratios is relatively flat. Of all sink particles formed within the ten minihaloes, approx. 50 are lost to mergers with larger sinks, and 50 of the remaining sinks are ejected from their star-forming disks. The large binary fraction may have important implications for Pop III evolution and nucleosynthesis, as well as the final fate of the first stars.

  3. Observations of binary stars by speckle interferometry

    International Nuclear Information System (INIS)

    Morgan, B.L.; Beckmann, G.K.; Scaddan, R.J.

    1980-01-01

    This is the second paper in a series describing observations of binary stars using the technique of speckle interferometry. Observations were made using the 2.5-m Isaac Newton Telescope and the 1-m telescope of the Royal Greenwich Observatory and the 1.9-m telescope of the South African Astronomical Observatory. The classical Rayleigh diffraction limits are 0.050 arcsec for the 2.5-m telescope, 0.065 arcsec for the 1.9-m telescope and 0.125 arcsec for the 1-m telescope, at a wavelength of 500 nm. The results of 29 measurements of 26 objects are presented. The objects include long period spectroscopic binaries from the 6th Catalogue of Batten, close visual binary systems from the 3rd Catalogue of Finsen and Worley and variable stars. Nine of the objects have not been previously resolved by speckle interferometry. New members are detected in the systems β Cep, p Vel and iota UMa. (author)

  4. On the binary expansions of algebraic numbers

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, David H.; Borwein, Jonathan M.; Crandall, Richard E.; Pomerance, Carl

    2003-07-01

    Employing concepts from additive number theory, together with results on binary evaluations and partial series, we establish bounds on the density of 1's in the binary expansions of real algebraic numbers. A central result is that if a real y has algebraic degree D > 1, then the number {number_sign}(|y|, N) of 1-bits in the expansion of |y| through bit position N satisfies {number_sign}(|y|, N) > CN{sup 1/D} for a positive number C (depending on y) and sufficiently large N. This in itself establishes the transcendency of a class of reals {summation}{sub n{ge}0} 1/2{sup f(n)} where the integer-valued function f grows sufficiently fast; say, faster than any fixed power of n. By these methods we re-establish the transcendency of the Kempner--Mahler number {summation}{sub n{ge}0}1/2{sup 2{sup n}}, yet we can also handle numbers with a substantially denser occurrence of 1's. Though the number z = {summation}{sub n{ge}0}1/2{sup n{sup 2}} has too high a 1's density for application of our central result, we are able to invoke some rather intricate number-theoretical analysis and extended computations to reveal aspects of the binary structure of z{sup 2}.

  5. Accreting Binary Populations in the Earlier Universe

    Science.gov (United States)

    Hornschemeier, Ann

    2010-01-01

    It is now understood that X-ray binaries dominate the hard X-ray emission from normal star-forming galaxies. Thanks to the deepest (2-4 Ms) Chandra surveys, such galaxies are now being studied in X-rays out to z approximates 4. Interesting X-ray stacking results (based on 30+ galaxies per redshift bin) suggest that the mean rest-frame 2-10 keV luminosity from z=3-4 Lyman break galaxies (LBGs), is comparable to the most powerful starburst galaxies in the local Universe. This result possibly indicates a similar production mechanism for accreting binaries over large cosmological timescales. To understand and constrain better the production of X-ray binaries in high-redshift LBGs, we have utilized XMM-Newton observations of a small sample of z approximates 0.1 GALEX-selected Ultraviolet-Luminous Galaxies (UVLGs); local analogs to high-redshift LBGs. Our observations enable us to study the X-ray emission from LBG-like galaxies on an individual basis, thus allowing us to constrain object-to-object variances in this population. We supplement these results with X-ray stacking constraints using the new 3.2 Ms Chandra Deep Field-South (completed spring 2010) and LBG candidates selected from HST, Swift UVOT, and ground-based data. These measurements provide new X-ray constraints that sample well the entire z=0-4 baseline

  6. Asteroseismic modelling of the Binary HD 176465

    Directory of Open Access Journals (Sweden)

    Nsamba B.

    2017-01-01

    Full Text Available The detection and analysis of oscillations in binary star systems is critical in understanding stellar structure and evolution. This is partly because such systems have the same initial chemical composition and age. Solar-like oscillations have been detected by Kepler in both components of the asteroseismic binary HD 176465. We present an independent modelling of each star in this binary system. Stellar models generated using MESA (Modules for Experiments in Stellar Astrophysics were fitted to both the observed individual frequencies and complementary spectroscopic parameters. The individual theoretical oscillation frequencies for the corresponding stellar models were obtained using GYRE as the pulsation code. A Bayesian approach was applied to find the probability distribution functions of the stellar parameters using AIMS (Asteroseismic Inference on a Massive Scale as the optimisation code. The ages of HD 176465 A and HD 176465 B were found to be 2.81 ± 0.48 Gyr and 2.52 ± 0.80 Gyr, respectively. These results are in agreement when compared to previous studies carried out using other asteroseismic modelling techniques and gyrochronology.

  7. Infalling clouds on to supermassive black hole binaries - II. Binary evolution and the final parsec problem

    Science.gov (United States)

    Goicovic, Felipe G.; Sesana, Alberto; Cuadra, Jorge; Stasyszyn, Federico

    2017-11-01

    The formation of massive black hole binaries (MBHBs) is an unavoidable outcome of galaxy evolution via successive mergers. However, the mechanism that drives their orbital evolution from parsec separations down to the gravitational wave dominated regime is poorly understood, and their final fate is still unclear. If such binaries are embedded in gas-rich and turbulent environments, as observed in remnants of galaxy mergers, the interaction with gas clumps (such as molecular clouds) may efficiently drive their orbital evolution. Using numerical simulations, we test this hypothesis by studying the dynamical evolution of an equal mass, circular MBHB accreting infalling molecular clouds. We investigate different orbital configurations, modelling a total of 13 systems to explore different possible impact parameters and relative inclinations of the cloud-binary encounter. We focus our study on the prompt, transient phase during the first few orbits when the dynamical evolution of the binary is fastest, finding that this evolution is dominated by the exchange of angular momentum through gas capture by the individual black holes and accretion. Building on these results, we construct a simple model for evolving an MBHB interacting with a sequence of clouds, which are randomly drawn from reasonable populations with different levels of anisotropy in their angular momenta distributions. We show that the binary efficiently evolves down to the gravitational wave emission regime within a few hundred million years, overcoming the 'final parsec' problem regardless of the stellar distribution.

  8. Double stars with wide separations in the AGK3 - I. Components that are themselves spectroscopic binaries

    Science.gov (United States)

    Halbwachs, J.-L.; Mayor, M.; Udry, S.

    2012-05-01

    Wide binaries are tracers of the gravity field of the Galaxy, but their study requires some caution. A large list of common proper motion stars selected from the third Astronomischen Gesellschaft Katalog (AGK3) was monitored with the CORAVEL (for COrrelation RAdial VELocities) spectrovelocimeter, in order to prepare a sample of physical binaries with very wide separations. 66 stars received special attention, since their radial velocities (RV) seemed to be variable. These stars were monitored over several years in order to derive the elements of their spectroscopic orbits. In addition, 10 of them received accurate RV measurements from the SOPHIE spectrograph of the T193 telescope at the Observatory of Haute-Provence. For deriving the orbital elements of double-lined spectroscopic binaries (SB2), a new method was applied, which assumed that the RV of blended measurements are linear combinations of the RV of the components. 13 SB2 orbits were thus calculated. The orbital elements were eventually obtained for 52 spectroscopic binaries (SB), two of them making a triple system. 40 SB received their first orbit and the orbital elements were improved for 10 others. In addition, 11 SB were discovered with very long periods for which the orbital parameters were not found. The median period of the 40 first orbits is 1 yr, and several SB should be resolved or should receive an astrometric orbit in future, providing the masses of the components. In addition, it appeared that HD 153252 has a close companion, which is a candidate brown dwarf with a minimum mass of 50 Jupiter masses. The final selection of wide binaries and the derivation of their statistical properties will be presented in a second paper.

  9. Thermodynamic studies of mixtures for topical anesthesia: Lidocaine-salol binary phase diagram

    Energy Technology Data Exchange (ETDEWEB)

    Lazerges, Mathieu [Laboratoire de Chimie Physique (EA 4066), Faculte des Sciences Pharmaceutiques et Biologiques, Universite Paris Descartes, 4 Avenue de l' Observatoire, 75270 Paris Cedex 06 (France); Rietveld, Ivo B., E-mail: ivo.rietveld@parisdescartes.fr [Laboratoire de Chimie Physique (EA 4066), Faculte des Sciences Pharmaceutiques et Biologiques, Universite Paris Descartes, 4 Avenue de l' Observatoire, 75270 Paris Cedex 06 (France); Corvis, Yohann; Ceolin, Rene; Espeau, Philippe [Laboratoire de Chimie Physique (EA 4066), Faculte des Sciences Pharmaceutiques et Biologiques, Universite Paris Descartes, 4 Avenue de l' Observatoire, 75270 Paris Cedex 06 (France)

    2010-01-10

    The lidocaine-salol binary system has been investigated by differential scanning calorimetry, direct visual observations, and X-ray powder diffraction, resulting in a temperature-composition phase diagram with a eutectic equilibrium. The eutectic mixture, found at 0.423 {+-} 0.007 lidocaine mole-fraction, melts at 18.2 {+-} 0.5 {sup o}C with an enthalpy of 17.3 {+-} 0.5 kJ mol{sup -1}. This indicates that the liquid phase around the eutectic composition is stable at room temperature. Moreover, the undercooled liquid mixture does not easily crystallize. The present binary mixture exhibits eutectic behavior similar to the prilocaine-lidocaine mixture in the widely used EMLA topical anesthetic preparation.

  10. The formation of eccentric compact binary inspirals and the role of gravitational wave emission in binary-single stellar encounters

    International Nuclear Information System (INIS)

    Samsing, Johan; MacLeod, Morgan; Ramirez-Ruiz, Enrico

    2014-01-01

    The inspiral and merger of eccentric binaries leads to gravitational waveforms distinct from those generated by circularly merging binaries. Dynamical environments can assemble binaries with high eccentricity and peak frequencies within the LIGO band. In this paper, we study binary-single stellar scatterings occurring in dense stellar systems as a source of eccentrically inspiraling binaries. Many interactions between compact binaries and single objects are characterized by chaotic resonances in which the binary-single system undergoes many exchanges before reaching a final state. During these chaotic resonances, a pair of objects has a non-negligible probability of experiencing a very close passage. Significant orbital energy and angular momentum are carried away from the system by gravitational wave (GW) radiation in these close passages, and in some cases this implies an inspiral time shorter than the orbital period of the bound third body. We derive the cross section for such dynamical inspiral outcomes through analytical arguments and through numerical scattering experiments including GW losses. We show that the cross section for dynamical inspirals grows with increasing target binary semi-major axis a and that for equal-mass binaries it scales as a 2/7 . Thus, we expect wide target binaries to predominantly contribute to the production of these relativistic outcomes. We estimate that eccentric inspirals account for approximately 1% of dynamically assembled non-eccentric merging binaries. While these events are rare, we show that binary-single scatterings are a more effective formation channel than single-single captures for the production of eccentrically inspiraling binaries, even given modest binary fractions.

  11. All-optical conversion scheme: Binary to quaternary and quaternary to binary number

    Science.gov (United States)

    Chattopadhyay, Tanay; Roy, Jitendra Nath

    2009-04-01

    To achieve the inherent parallelism in optics a suitable number system and efficient encoding/decoding scheme for handling the data are very much essential. Binary number is accepted as the best representing number system in almost all types of existing electronic computers. But, binary number (0 and 1) is insufficient in respect to the demand of the coming generation. Multi-valued logic (with radix >2) can be viewed as an alternative approach to solve many problems in transmission, storage and processing of large amount of information in digital signal processing. Here, in this paper all-optical scheme for the conversion of binary to quaternary number and vice versa have been proposed and described. Simulation has also been done. In this all-optical scheme the numbers are represented by different discrete polarized state of light.

  12. Searching Ultra-compact Pulsar Binaries with Abnormal Timing Behavior

    Science.gov (United States)

    Gong, B. P.; Li, Y. P.; Yuan, J. P.; Tian, J.; Zhang, Y. Y.; Li, D.; Jiang, B.; Li, X. D.; Wang, H. G.; Zou, Y. C.; Shao, L. J.

    2018-03-01

    Ultra-compact pulsar binaries are both ideal sources of gravitational radiation for gravitational wave detectors and laboratories for fundamental physics. However, the shortest orbital period of all radio pulsar binaries is currently 1.6 hr. The absence of pulsar binaries with a shorter orbital period is most likely due to technique limit. This paper points out that a tidal effect occurring on pulsar binaries with a short orbital period can perturb the orbital elements and result in a significant change in orbital modulation, which dramatically reduces the sensitivity of the acceleration searching that is widely used. Here a new search is proposed. The abnormal timing residual exhibited in a single pulse observation is simulated by a tidal effect occurring on an ultra-compact binary. The reproduction of the main features represented by the sharp peaks displayed in the abnormal timing behavior suggests that pulsars like PSR B0919+06 could be a candidate for an ultra-compact binary of an orbital period of ∼10 minutes and a companion star of a white dwarf star. The binary nature of such a candidate is further tested by (1) comparing the predicted long-term binary effect with decades of timing noise observed and (2) observing the optical counterpart of the expected companion star. Test (1) likely supports our model, while more observations are needed in test (2). Some interesting ultra-compact binaries could be found in the near future by applying such a new approach to other binary candidates.

  13. Inclination evolution of protoplanetary discs around eccentric binaries

    Science.gov (United States)

    Zanazzi, J. J.; Lai, Dong

    2018-01-01

    It is usually thought that viscous torque works to align a circumbinary disc with the binary's orbital plane. However, recent numerical simulations suggest that the disc may evolve to a configuration perpendicular to the binary orbit ('polar alignment) if the binary is eccentric and the initial disc-binary inclination is sufficiently large. We carry out a theoretical study on the long-term evolution of inclined discs around eccentric binaries, calculating the disc warp profile and dissipative torque acting on the disc. For discs with aspect ratio H/r larger than the viscosity parameter α, bending wave propagation effectively makes the disc precess as a quasi-rigid body, while viscosity acts on the disc warp and twist to drive secular evolution of the disc-binary inclination. We derive a simple analytic criterion (in terms of the binary eccentricity and initial disc orientation) for the disc to evolve towards polar alignment with the eccentric binary. When the disc has a non-negligible angular momentum compared to the binary, the final 'polar alignment' inclination angle is reduced from 90°. For typical protoplanetary disc parameters, the time-scale of the inclination evolution is shorter than the disc lifetime, suggesting that highly inclined discs and planets may exist orbiting eccentric binaries.

  14. Radioprotective preparation

    International Nuclear Information System (INIS)

    Stefanova, D.; Frattadochi, A.; Gattavecchia, E.; Ferri, E.; Tonnelli, D.

    1988-01-01

    The invention is intended for radiation injuries prophylaxis in mammals. It has an well expressed radioprotective effect against acute gamma irradiation on cellular level as well as a prolonged action when applied up to 48 hours before the acute irradiation. The preparation is a coprecipitate of the natural tripeptide glutathione (reduced form) and polyvinyl pyrrolidone (pvp) in ratio 30-60/70-40. It is obtained by incubation method with subsequent lyophilization from water solution of the initial components. The molecular mass of the pvp is 20 till 360.10 3 . 2 claims

  15. Eclipsing binaries observed with the WIRE satellite I. Discovery and photometric analysis of the new bright A0 IV eclipsing binary psi centauri

    DEFF Research Database (Denmark)

    Bruntt, Hans; Southworth, J.; Penny, A. J.

    2006-01-01

    Stars: fundamental parameters, binaries: close, eclipsing, techniques: photometric Udgivelsesdato: Sep.......Stars: fundamental parameters, binaries: close, eclipsing, techniques: photometric Udgivelsesdato: Sep....

  16. The Fate of Neutron Star Binary Mergers

    Energy Technology Data Exchange (ETDEWEB)

    Piro, Anthony L. [The Observatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Giacomazzo, Bruno [Physics Department, University of Trento, via Sommarive 14, I-38123 Trento (Italy); Perna, Rosalba, E-mail: piro@carnegiescience.edu [Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794 (United States)

    2017-08-01

    Following merger, a neutron star (NS) binary can produce roughly one of three different outcomes: (1) a stable NS, (2) a black hole (BH), or (3) a supramassive, rotationally supported NS, which then collapses to a BH following angular momentum losses. Which of these fates occur and in what proportion has important implications for the electromagnetic transient associated with the mergers and the expected gravitational wave (GW) signatures, which in turn depend on the high density equation of state (EOS). Here we combine relativistic calculations of NS masses using realistic EOSs with Monte Carlo population synthesis based on the mass distribution of NS binaries in our Galaxy to predict the distribution of fates expected. For many EOSs, a significant fraction of the remnants are NSs or supramassive NSs. This lends support to scenarios in which a quickly spinning, highly magnetized NS may be powering an electromagnetic transient. This also indicates that it will be important for future GW observatories to focus on high frequencies to study the post-merger GW emission. Even in cases where individual GW events are too low in signal to noise to study the post merger signature in detail, the statistics of how many mergers produce NSs versus BHs can be compared with our work to constrain the EOS. To match short gamma-ray-burst (SGRB) X-ray afterglow statistics, we find that the stiffest EOSs are ruled out. Furthermore, many popular EOSs require a significant fraction of ∼60%–70% of SGRBs to be from NS–BH mergers rather than just binary NSs.

  17. Binary Classification Method of Social Network Users

    Directory of Open Access Journals (Sweden)

    I. A. Poryadin

    2017-01-01

    Full Text Available The subject of research is a binary classification method of social network users based on the data analysis they have placed. Relevance of the task to gain information about a person by examining the content of his/her pages in social networks is exemplified. The most common approach to its solution is a visual browsing. The order of the regional authority in our country illustrates that its using in school education is needed. The article shows restrictions on the visual browsing of pupil’s pages in social networks as a tool for the teacher and the school psychologist and justifies that a process of social network users’ data analysis should be automated. Explores publications, which describe such data acquisition, processing, and analysis methods and considers their advantages and disadvantages. The article also gives arguments to support a proposal to study the classification method of social network users. One such method is credit scoring, which is used in banks and credit institutions to assess the solvency of clients. Based on the high efficiency of the method there is a proposal for significant expansion of its using in other areas of society. The possibility to use logistic regression as the mathematical apparatus of the proposed method of binary classification has been justified. Such an approach enables taking into account the different types of data extracted from social networks. Among them: the personal user data, information about hobbies, friends, graphic and text information, behaviour characteristics. The article describes a number of existing methods of data transformation that can be applied to solve the problem. An experiment of binary gender-based classification of social network users is described. A logistic model obtained for this example includes multiple logical variables obtained by transforming the user surnames. This experiment confirms the feasibility of the proposed method. Further work is to define a system

  18. Studies of Gas Disks in Binary Systems

    Science.gov (United States)

    de Val-Borro, Miguel

    There are over 300 exoplanets detected through radial velocity surveys and photometric studies showing a tremendous variety of masses, compositions and orbital parameters. Understanding the way these planets formed and evolved within the circumstellar disks they were initially embedded in is a crucial issue. In the first part of this thesis we study the physical interaction between a gaseous protoplanetary disk and an embedded planet using numerical simulations. In order to trust the results from simulations it is important to compare different methods. However, the standard test problems for hydrodynamic codes differ considerably from the case of a protoplanetary disk interacting with an embedded planet. We have carried out a code comparison in which the problem of a massive planet in a protoplanetary disk was studied with various numerical schemes. We compare the surface density, potential vorticity and azimuthally averaged density profiles at several times. There is overall good agreement between our codes for Neptune and Jupiter-sized planets. We performed simulations for each planet in an inviscid disk and including physical viscosity. The surface density profiles agree within about 5% for the grid-based schemes while the particle codes have less resolution in the low density regions and weaker spiral wakes. In Paper II, we study hydrodynamical instabilities in disks with planets. Vortices are generated close to the gap in our numerical models in agreement with the linear modal analysis. The vortices exert strong perturbations on the planet as they move along the gap and can change its migration rate. In addition, disk viscosity can be modified by the presence of vortices. The last part of this thesis studies the mass transfer in symbiotic binaries and close T Tauri binary systems. Our simulations of gravitationally focused wind accretion in binary systems show the formation of stream flows and enhanced accretion rates onto the compact component.

  19. Formation and Evolution of Binary Asteroids

    Science.gov (United States)

    Walsh, K. J.; Jacobson, S. A.

    Satellites of asteroids have been discovered in nearly every known small-body population, and a remarkable aspect of the known satellites is the diversity of their properties. They tell a story of vast differences in formation and evolution mechanisms that act as a function of size, distance from the Sun, and the properties of their nebular environment at the beginning of solar system history and their dynamical environment over the next 4.5 G.y. The mere existence of these systems provides a laboratory to study numerous types of physical processes acting on asteroids, and their dynamics provide a valuable probe of their physical properties otherwise possible only with spacecraft. Advances in understanding the formation and evolution of binary systems have been assisted by (1) the growing catalog of known systems, increasing from 33 to ~250 between the Merline et al. (2002) chapter in Asteroids III and now; (2) the detailed study and long-term monitoring of individual systems such as 1999 KW4 and 1996 FG3, (3) the discovery of new binary system morphologies and triple systems, (4) and the discovery of unbound systems that appear to be end-states of binary dynamical evolutionary paths. Specifically for small bodies (diameter smaller than 10 km), these observations and discoveries have motivated theoretical work finding that thermal forces can efficiently drive the rotational disruption of small asteroids. Long-term monitoring has allowed studies to constrain the system's dynamical evolution by the combination of tides, thermal forces, and rigid-body physics. The outliers and split pairs have pushed the theoretical work to explore a wide range of evolutionary end-states.

  20. Electronic band structures of binary skutterudites

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Banaras [Center for Computational Materials Science, University of Malakand, Chakdara (Pakistan); Department of Physics, University of Malakand, Chakdara (Pakistan); Aliabad, H.A. Rahnamaye [Department of Physics, Hakim Sabzevari University, Sabzevar (Iran, Islamic Republic of); Saifullah [Center for Computational Materials Science, University of Malakand, Chakdara (Pakistan); Department of Physics, University of Malakand, Chakdara (Pakistan); Jalali-Asadabadi, S. [Department of Physics, Faculty of Science, University of Isfahan (UI), 81744 Isfahan (Iran, Islamic Republic of); Khan, Imad [Center for Computational Materials Science, University of Malakand, Chakdara (Pakistan); Department of Physics, University of Malakand, Chakdara (Pakistan); Ahmad, Iftikhar, E-mail: ahma5532@gmail.com [Center for Computational Materials Science, University of Malakand, Chakdara (Pakistan); Department of Physics, University of Malakand, Chakdara (Pakistan)

    2015-10-25

    The electronic properties of complex binary skutterudites, MX{sub 3} (M = Co, Rh, Ir; X = P, As, Sb) are explored, using various density functional theory (DFT) based theoretical approaches including Green's Function (GW) as well as regular and non-regular Tran Blaha modified Becke Jhonson (TB-mBJ) methods. The wide range of calculated bandgap values for each compound of this skutterudites family confirm that they are theoretically as challenging as their experimental studies. The computationally expensive GW method, which is generally assume to be efficient in the reproduction of the experimental bandgaps, is also not very successful in the calculation of bandgaps. In this article, the issue of the theoretical bandgaps of these compounds is resolved by reproducing the accurate experimental bandgaps, using the recently developed non-regular TB-mBJ approach, based on DFT. The effectiveness of this technique is due to the fact that a large volume of the binary skutterudite crystal is empty and hence quite large proportion of electrons lie outside of the atomic spheres, where unlike LDA and GGA which are poor in the treatment of these electrons, this technique properly treats these electrons and hence reproduces the clear electronic picture of these compounds. - Highlights: • Theoretical and experimental electronic band structures of binary skutterudites are reviewed. • The literature reveals that none of the existing theoretical results are consistent with the experiments. • GW, regular and non-regular TB-mBJ methods are used to reproduce the correct results. • The GW and regular TB-mBJ results are better than the available results in literature. • However, non-regular TB-mBJ reproduces the correct experimental band structures.

  1. Electronic band structures of binary skutterudites

    International Nuclear Information System (INIS)

    Khan, Banaras; Aliabad, H.A. Rahnamaye; Saifullah; Jalali-Asadabadi, S.; Khan, Imad; Ahmad, Iftikhar

    2015-01-01

    The electronic properties of complex binary skutterudites, MX 3 (M = Co, Rh, Ir; X = P, As, Sb) are explored, using various density functional theory (DFT) based theoretical approaches including Green's Function (GW) as well as regular and non-regular Tran Blaha modified Becke Jhonson (TB-mBJ) methods. The wide range of calculated bandgap values for each compound of this skutterudites family confirm that they are theoretically as challenging as their experimental studies. The computationally expensive GW method, which is generally assume to be efficient in the reproduction of the experimental bandgaps, is also not very successful in the calculation of bandgaps. In this article, the issue of the theoretical bandgaps of these compounds is resolved by reproducing the accurate experimental bandgaps, using the recently developed non-regular TB-mBJ approach, based on DFT. The effectiveness of this technique is due to the fact that a large volume of the binary skutterudite crystal is empty and hence quite large proportion of electrons lie outside of the atomic spheres, where unlike LDA and GGA which are poor in the treatment of these electrons, this technique properly treats these electrons and hence reproduces the clear electronic picture of these compounds. - Highlights: • Theoretical and experimental electronic band structures of binary skutterudites are reviewed. • The literature reveals that none of the existing theoretical results are consistent with the experiments. • GW, regular and non-regular TB-mBJ methods are used to reproduce the correct results. • The GW and regular TB-mBJ results are better than the available results in literature. • However, non-regular TB-mBJ reproduces the correct experimental band structures

  2. Magic structures of binary metallic clusters

    Science.gov (United States)

    Ferrando, Riccardo

    2005-03-01

    The structure of binary metallic clusters is investigated by a variety of computational tools, ranging from genetic and basin-hopping global optimization algorithms, to molecular dynamics, and to density-functional calculations. Three different binary systems are investigated: Ag-Cu, Ag-Ni, and Ag-Pd. A new family of magic cluster structures is found. These clusters have the common feature of presenting a perfect core-shell chemical arrangement (with an outer Ag shell of monoatomic thickness) and of being polyicosahedra, that is being made of interpenetrating icosahedra of 13 atoms. Core-shell polyicosahedra are of special stability, which originates from the interplay of different factors. First of all, polyicosahedra are very compact structures, so that they maximize the number of nearest-neighbor bonds for a given size. However, in single-element clusters, these bonds are not optimal, since inner bonds are strongly compressed and surface bonds are expanded. This is the contrary of what is required from the bond order -bond length correlation in metals, which favors contracted surface bonds. In binary clusters, the situation is different. Substituting the inner atoms of a single-element polyicosahedron with different atoms of smaller size, the bonds can relax close to their optimal distance. This leads naturally to the appearance of core-shell polyicosahedra. In Ag-Cu, Ag-Ni and Ag-Pd the formation of these structures is reinforced by the tendency of Ag atoms to surface segregation. A similar mechanism of structural relaxation, originating from the interplay of cluster geometry and bond order - bond length correlation, is also the cause of the destabilization of icosahedral structures in pure Pt and Au clusters . In these clusters, the compressed inner atoms of the icosahedra can relax because of the formation of rosette structures at vertices in the outer layer.

  3. Evaporation of binary mixtures in microgravity

    Science.gov (United States)

    Girgis, Morris; Matta, Nabil; Kolli, Kiran; Brown, Leon; Chubb, Kevin

    1995-01-01

    The motivation of this research is to obtain a better understanding of phase-change heat transfer within single and binary liquid meniscii, both in 1-g and 0-g environments. During phase 1 and part of phase 2, in a glass test cell with an inclined heated plate, 1-6 experiments on pentane with additions of decane up to 3% were conducted to determine the optimum concentration that will exhibit the maximum heat transfer and stability. During phase 2 emphasis was given to explore fundamental research issues and to ultimately develop a reliable capillary pumped loop (CPL) device for low gravity. In related experimental work, it was found that thermocapillary stresses near the contract line could result in a degraded wettability which ultimately could explain the observed failure of CPL devices in zero-gravity environment. Therefore, the current experimental effort investigates the effect of adding binary constituents in improving the thermocapillary characteristics near the contact line within the loop configuration. Achievements during second phase include: (1) Further enhancement of Central State University's Microgravity Laboratory by adding or improving upon capabilities of photography, video imaging, fluid visualization, and general experimental testing capabilities; (2) Experimental results for the inclined plate cell; (3) Modeling effort with a detailed scaling analysis; (4) Additional testing with a tube loop configuration to extend experimental work by Dickens, et al.; (5) Fabrication of a capillary loop to be tested using binary fluid (pentane/decane). The device that has been recently completed will be set up horizontally so that the effect of gravity on the performance is negligible. Testing will cover a wide range of parameters such as decane/pentane concentration, heat input value, heat input location (below or above meniscus), and loop temperature.

  4. Sn-Mn binary metal oxides as non-carbon sorbent for mercury removal in a wide-temperature window.

    Science.gov (United States)

    Xie, Jiangkun; Xu, Haomiao; Qu, Zan; Huang, Wenjun; Chen, Wanmiao; Ma, Yongpeng; Zhao, Songjian; Liu, Ping; Yan, Naiqiang

    2014-08-15

    A series of Sn-Mn binary metal oxides were prepared through co-precipitation method. The sorbents were characterized by powder X-ray diffraction (powder XRD), transmission electronic microscopy (TEM), H2-temperature-programmed reduction (H2-TPR) and NH3-temperature-programmed desorption (NH3-TPD) methods. The capability of the prepared sorbents for mercury adsorption from simulated flue gas was investigated by fixed-bed experiments. Results showed that mercury adsorption on pure SnO2 particles was negligible in the test temperature range, comparatively, mercury capacity on MnOx at low temperature was relative high, but the capacity would decrease significantly when the temperature was elevated. Interestingly, for Sn-Mn binary metal oxide, mercury capacity increased not only at low temperature but also at high temperature. Furthermore, the impact of SO2 on mercury adsorption capability of Sn-Mn binary metal oxides was also investigated and it was noted that the effect at low temperature was different comparing with that of high temperature. The mechanism was investigated by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTs). Moreover, a mathematic model was built to calculate mercury desorption activation energy from Sn to Mn binary metal oxides. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Ação sonoquímica e influência das condições de tratamento térmico na preparação de cimentos do sistema binário CaO-Al2O3 Sonochemical action and the influence of heat treatment conditions on the preparation of cements of the CaO-Al2O3 binary system

    Directory of Open Access Journals (Sweden)

    R. R Lourenço

    2010-03-01

    Full Text Available Foram preparados cimentos do sistema binário CaO-Al2O3 por meio de uma rota que emprega o processo sonoquímico seguido de tratamento térmico. Convencionalmente estes compostos são fabricados a partir da fusão ou da sinterização de uma mistura de calcário com bauxito ou com alumina. O maior inconveniente associado a este tipo de síntese é a necessidade de temperaturas elevadas e o grande consumo de energia. Na rota sonoquímica a cálcia, juntamente com a alumina em suspensão aquosa, são introduzidas num banho de ultra-som por tempo determinado. Em seguida, após a evaporação da água, o material resultante é tratado termicamente. Quando um sistema é submetido ao processo sonoquímico, alterações na morfologia superficial das partículas podem ser induzidas pelas ondas ultra-sônicas, incluindo a redução do tamanho dessas partículas. Como conseqüência, estes materiais tornam-se mais reativos, facilitando a síntese final dos aluminatos de cálcio durante o tratamento térmico. Foi estudada a ação das ondas ultra-sônicas e a influência das condições de tratamento térmico em duas composições molares de cálcia:alumina de 1:1 e 1:2. As temperaturas empregadas foram 1000 ºC, 1200 ºC e 1300 ºC com patamares de 1 e 6 h. O material obtido foi caracterizado por microscopia eletrônica de varredura, difração de raios X e as fases presentes foram semi-quantificadas pelo método de Rietveld. Também foram realizados ensaios de compressão diametral para avaliar a resistência mecânica dos produtos da síntese. Foram preparadas pastas constituídas de cimento, alumina e água, utilizando como cimento os aluminatos de cálcio preparados pelo processo sonoquímico e um cimento comercial, como referência.Cements of the CaO-Al2O3 binary system were prepared through a sonochemical process at room temperature followed by heat treatment. The conventional production consists of a reaction in which a stoichiometric mixture of

  6. Disordered multihyperuniformity derived from binary plasmas

    Science.gov (United States)

    Lomba, Enrique; Weis, Jean-Jacques; Torquato, Salvatore

    2018-01-01

    Disordered multihyperuniform many-particle systems are exotic amorphous states that allow exquisite color sensing capabilities due to their anomalous suppression of density fluctuations for distinct subsets of particles, as recently evidenced in photoreceptor mosaics in avian retina. Motivated by this biological finding, we present a statistical-mechanical model that rigorously achieves disordered multihyperuniform many-body systems by tuning interactions in binary mixtures of nonadditive hard-disk plasmas. We demonstrate that multihyperuniformity competes with phase separation and stabilizes a clustered phase. Our work provides a systematic means to generate disordered multihyperuniform solids, and hence lays the groundwork to explore their potentially unique photonic, phononic, electronic, and transport properties.

  7. Diffusive flux of energy in binary mixtures

    International Nuclear Information System (INIS)

    Sampaio, R.S.

    1976-04-01

    The diffusive flux of energy j tilde is studied through the reduced diffusive flux of energy K tilde, which obeys equations of the form: sim(delta K tilde/delta grad rho sub(α))= sim(delta K tilde/delta grad theta)=0. By a representation theorem, herein proved, is obtained a general representation for K tilde which is simplified, for the case of binary mixtures, using the principle of objectivity. Some consequences of this representation are discussed such as the symmetry of the partial stresses T 1 tilde and T 2 tilde and the difference between the normal stresses [pt

  8. Dynamic Binary Modification Tools, Techniques and Applications

    CERN Document Server

    Hazelwood, Kim

    2011-01-01

    Dynamic binary modification tools form a software layer between a running application and the underlying operating system, providing the powerful opportunity to inspect and potentially modify every user-level guest application instruction that executes. Toolkits built upon this technology have enabled computer architects to build powerful simulators and emulators for design-space exploration, compiler writers to analyze and debug the code generated by their compilers, software developers to fully explore the features, bottlenecks, and performance of their software, and even end-users to extend

  9. in Binary Liquid Mixtures of Ethyl benzoate

    Directory of Open Access Journals (Sweden)

    Shaik Babu

    2012-01-01

    Full Text Available Ultrasonic velocity is measured at 2MHz frequency in the binary mixtures of Ethyl Benzoate with 1-Propanol, 1-Butanol, 1-Pentanol and theoretical values of ultrasonic velocity have been evaluated at 303K using Nomoto's relation, Impedance relation, Ideal mixture relation, Junjie's method and free length theory. Theoretical values are compared with the experimental values and the validity of the theories is checked by applying the chi-square test for goodness of fit and by calculating the average percentage error (APE. A good agreement has been found between experimental and Nomoto’s ultrasonic velocity.

  10. A unified kinetic approach to binary nucleation

    Energy Technology Data Exchange (ETDEWEB)

    Kevrekidis, P.G. [Department of Physics, Rutgers University, 136 Frelinghuysen Road]|[E.O.H.S.I., Rutgers University]|[UMDNJ, 170 Frelinghuysen Road, Piscataway, New Jersey 08854-8019 (United States); Lazaridis, M. [Norwegian Institute for Air Research (NILU), Instittutvein 18, P. O. Box 100, N-2007 Kjeller (Norway); Drossinos, Y. [European Commission, Joint Research Centre, I-21020 Ispra (Vatican City State, Holy See) (Italy); Georgopoulos, P.G. [E.O.H.S.I., Rutgers University]|[UMDNJ, 170 Frelinghuysen Road, Piscataway, New Jersey 08854 (United States)

    1999-11-01

    Two different methods to calculate the steady-state nucleation rate in heteromolecular systems proposed by Stauffer (1976) and Langer (1969) are analyzed. Their mathematical equivalence is explicitly demonstrated, thereby obtaining a generic expression for the rate of binary nucleation. Its numerical evaluation does not entail rotation of the coordinate system at the saddle point, but it only requires data in the natural coordinate system of number fluctuations, namely molecular impingement rates, the droplet free energy and its second order derivatives at the saddle point, and the total density of condensible vapors. {copyright} {ital 1999 American Institute of Physics.}

  11. Binary breeder reactor with annular core

    International Nuclear Information System (INIS)

    Nascimento, J.A. do; Ishiguro, Y.

    1988-01-01

    Characteristics of a 1200 MWe binary breeder reactor with annular core fueled with metallic 233 U- 238 U-Zr, Pu- 238 U-Zr and Th in the blankets have been analyzed. The Doppler effect is small as expected in a metal fueled fast reactor. The sodium void reactivity is, in general, smaller than in homogeneous fast reactors fueled with metallic fuel and with 1 m core height. The worths of available control is high and there is a large shutdown margin throughout the operational cycle. There are flexibility in blankets fueling in the two cycles, uranium and thorium, with doubling times of about 20 years. (author) [pt

  12. Burnup characteristics of binary breeder reactors

    International Nuclear Information System (INIS)

    Dias, A.F.; Nascimento, J.A. do; Ishiguro, Y.

    1983-01-01

    Burnup calculations of a binary breeder reactor have been done for two cases of fueling. In one case the U 233 /TH fueled inner core and the Pu/U-fueled outer core have the same number of fuel assemblies. In the other case two outermost rings in the inner core are Pu/U-fueled. The second case is considered for an initial phase of thorim cycle introduction when the supply of U 233 could be limited. Results show an efficient breeding on the thorium cycle in both cases. (Author) [pt

  13. Pycnonuclear reaction rates for binary ionic mixtures

    Science.gov (United States)

    Ichimaru, S.; Ogata, S.; Van Horn, H. M.

    1992-01-01

    Through a combination of compositional scaling arguments and examinations of Monte Carlo simulation results for the interparticle separations in binary-ionic mixture (BIM) solids, we have derived parameterized expressions for the BIM pycnonuclear rates as generalizations of those in one-component solids obtained previously by Salpeter and Van Horn and by Ogata et al. We have thereby discovered a catalyzing effect of the heavier elements, which enhances the rates of reactions among the lighter elements when the charge ratio exceeds a critical value of approximately 2.3.

  14. HD 161306: a radiatively interacting Be binary?

    Czech Academy of Sciences Publication Activity Database

    Koubský, Pavel; Kotková, Lenka; Kraus, Michaela; Yang, S.; Šlechta, Miroslav; Harmanec, P.; Wolf, M.; Votruba, Viktor; Kubát, Jiří; Kubátová, Brankica; Niemczura, E.; Škoda, Petr

    2014-01-01

    Roč. 567, July (2014), A57/1-A57/4 ISSN 0004-6361 R&D Projects: GA ČR(CZ) GA14-21373S; GA MŠk LG14026 Grant - others:ESA(XE) ESA-PECS project no. 98058; GA ČR(CZ) GAP209/10/0715 Program:GA Institutional support: RVO:67985815 Keywords : binaries: spectroscopic * stars: emission -line * Be: stars Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 4.378, year: 2014

  15. The Boundary Layer in compact binaries

    OpenAIRE

    Hertfelder, Marius; Kley, Wilhelm; Suleimanov, Valery; Werner, Klaus

    2013-01-01

    Disk accretion onto stars leads to the formation of a Boundary Layer (BL) near the stellar surface where the disk makes contact with the star. Albeit a large fraction of the total luminosity of the system originates from this tiny layer connecting the accretion disk and the accreting object, its structure has not been fully understood yet. It is the aim of this work, to obtain more insight into the Boundary Layer around the white dwarf in compact binary systems. There are still many uncertain...

  16. Binary DNA nanostructures for data encryption.

    Directory of Open Access Journals (Sweden)

    Ken Halvorsen

    Full Text Available We present a simple and secure system for encrypting and decrypting information using DNA self-assembly. Binary data is encoded in the geometry of DNA nanostructures with two distinct conformations. Removing or leaving out a single component reduces these structures to an encrypted solution of ssDNA, whereas adding back this missing "decryption key" causes the spontaneous formation of the message through self-assembly, enabling rapid read out via gel electrophoresis. Applications include authentication, secure messaging, and barcoding.

  17. NONLINEAR TIDES IN CLOSE BINARY SYSTEMS

    International Nuclear Information System (INIS)

    Weinberg, Nevin N.; Arras, Phil; Quataert, Eliot; Burkart, Josh

    2012-01-01

    We study the excitation and damping of tides in close binary systems, accounting for the leading-order nonlinear corrections to linear tidal theory. These nonlinear corrections include two distinct physical effects: three-mode nonlinear interactions, i.e., the redistribution of energy among stellar modes of oscillation, and nonlinear excitation of stellar normal modes by the time-varying gravitational potential of the companion. This paper, the first in a series, presents the formalism for studying nonlinear tides and studies the nonlinear stability of the linear tidal flow. Although the formalism we present is applicable to binaries containing stars, planets, and/or compact objects, we focus on non-rotating solar-type stars with stellar or planetary companions. Our primary results include the following: (1) The linear tidal solution almost universally used in studies of binary evolution is unstable over much of the parameter space in which it is employed. More specifically, resonantly excited internal gravity waves in solar-type stars are nonlinearly unstable to parametric resonance for companion masses M' ∼> 10-100 M ⊕ at orbital periods P ≈ 1-10 days. The nearly static 'equilibrium' tidal distortion is, however, stable to parametric resonance except for solar binaries with P ∼ 3 [P/10 days] for a solar-type star) and drives them as a single coherent unit with growth rates that are a factor of ≈N faster than the standard three-wave parametric instability. These are local instabilities viewed through the lens of global analysis; the coherent global growth rate follows local rates in the regions where the shear is strongest. In solar-type stars, the dynamical tide is unstable to this collective version of the parametric instability for even sub-Jupiter companion masses with P ∼< a month. (4) Independent of the parametric instability, the dynamical and equilibrium tides excite a wide range of stellar p-modes and g-modes by nonlinear inhomogeneous forcing

  18. X-ray binaries, part 1

    International Nuclear Information System (INIS)

    Hammerschlag-Hensberge, G.C.M.J.

    1977-01-01

    Optical observations of X-ray binaries and their interpretation are described. A number of early-type stars which are identified as companions of X-ray sources are photometrically and spectroscopically observed. The spectra were obtained with the coude spectrograph attached to the 1.5 m telescope of the European Southern Observatory, La Silla, Chile. Registrations of the spectra were made with the Faul-Coradi microphotometer of the Observatory at Utrecht. To study radial velocity variations, the positions of the spectral lines were measured with the Grant comparator of the University of Groningen

  19. Electrostatic collection efficiency in binary fluidized beds

    Energy Technology Data Exchange (ETDEWEB)

    Romero, A.; Guardiola, J.; Rincon, J. (Univ. of Alcala de Henares, Madrid (Spain))

    1992-01-01

    Fluidized beds of binary mixtures have been used to clean air streams containing dust particles in the size range 4.4 to 14 {mu}m. All beds were composed of glass beads and plastic granules mixed at different proportions. The effect on the electrostatic collection efficiency of a number of variables, including type of collecting mixture, bed height, and gas velocity, was examined. To calculate the single collection efficiency from experimental results, an early model proposed by Clift et al. was used. The electrostatic collection efficiency was determined by subtracting the other individual mechanism efficiencies from the single particle collection efficiency.

  20. Gas filtration in binary fluidized beds

    Energy Technology Data Exchange (ETDEWEB)

    Rincon, J. (Univ. de Castilla-La Mancha, Ciudad Real (Spain)); Guardiola, J.; Romero, A. (Univ. de Alcala de Henares, Madrid (Spain))

    1992-12-01

    A systematic experimental study of aerosol filtration in a binary fluidized bed of dielectric material is carried out. Measurements of the collection efficiency when such parameters as gas velocity, bed height, collecting mixture, and column diameter are varied over a wide range have been made. Experimental evidence is given to show that charges generated naturally by triboelectrification of the bed dielectric particles can considerably increase the efficiency of such beds. Furthermore, it is demonstrated that a proper choice of the fluidized mixture can significantly improve the performance of such filters.

  1. On Binary-State Phyllosilicate Automata

    Science.gov (United States)

    Adamatzky, Andrew

    Phyllosilicate is a sheet of silicate tetrahedra bound by basal oxygens. A phyllosilicate automaton is a regular network of finite state machines, which mimics the structure of phyllosilicate. A node of a binary state phyllosilicate automaton takes states 0 and 1. A node updates its state in discrete time depending on a sum of states of its three (silicon nodes) or six (oxygen nodes) closest neighbors. We phenomenologically select the main types of patterns generated by phyllosilicate automata based on their shape: convex and concave hulls, almost circularly growing patterns, octagonal patterns, and those with dendritic growth; and, the patterns' interior: disordered, solid, labyrinthine. We also present the rules exhibiting traveling localizations.

  2. Binary Stars and Globular Cluster Dynamics

    Science.gov (United States)

    Fregeau, John M.

    2008-05-01

    In this brief proceedings article I summarize the review talk I gave at the IAU 246 meeting in Capri, Italy, glossing over the well-known results from the literature, but paying particular attention to new, previously unpublished material. This new material includes a careful comparison of the apparently contradictory results of two independent methods used to simulate the evolution of binary populations in dense stellar systems (the direct N-body method of Hurley, Aarseth, & Shara (2007) and the approximate Monte Carlo method of Ivanova et al. (2005)), that shows that the two methods may not actually yield contradictory results, and suggests future work to more directly compare the two methods.

  3. Physical Structure of Four Symbiotic Binaries

    Science.gov (United States)

    Kenyon, Scott J. (Principal Investigator)

    1997-01-01

    Disk accretion powers many astronomical objects, including pre-main sequence stars, interacting binary systems, and active galactic nuclei. Unfortunately, models developed to explain the behavior of disks and their surroundings - boundary layers, jets, and winds - lack much predictive power, because the physical mechanism driving disk evolution - the viscosity - is not understood. Observations of many types of accreting systems are needed to constrain the basic physics of disks and provide input for improved models. Symbiotic stars are an attractive laboratory for studying physical phenomena associated with disk accretion. These long period binaries (P(sub orb) approx. 2-3 yr) contain an evolved red giant star, a hot companion, and an ionized nebula. The secondary star usually is a white dwarf accreting material from the wind of its red giant companion. A good example of this type of symbiotic is BF Cygni: our analysis shows that disk accretion powers the nuclear burning shell of the hot white dwarf and also manages to eject material perpendicular to the orbital plane (Mikolajewska, Kenyon, and Mikolajewski 1989). The hot components in other symbiotic binaries appear powered by tidal overflow from a very evolved red giant companion. We recently completed a study of CI Cygni and demonstrated that the accreting secondary is a solar-type main sequence star, rather than a white dwarf (Kenyon et aL 1991). This project continued our study of symbiotic binary systems. Our general plan was to combine archival ultraviolet and optical spectrophotometry with high quality optical radial velocity observations to determine the variation of line and continuum sources as functions of orbital phase. We were very successful in generating orbital solutions and phasing UV+optical spectra for five systems: AG Dra, V443 Her, RW Hya, AG Peg, and AX Per. Summaries of our main results for these systems appear below. A second goal of our project was to consider general models for the

  4. Binary Modulation Formats in Optical Access Networks

    Directory of Open Access Journals (Sweden)

    Vladimir Tejkal

    2010-01-01

    Full Text Available In this paper the binary modulation formats and their application in passive optical networks have been discussed. Passive optical networks are characterized by dividing the optical signal between several end users by using passive splitters, which added a significant attenuation to the network. The performance of the selected modulation formats, depending on the transmitter power in order to verify that there is no signal distortion, has been examined in our simulations. A minimal error rate of the system for each modulation format has been also examined. Finding a suitable modulation, which would allow extension of the distance and splitting ration in current passive optical networks, has been the main aim.

  5. Astronomical Plate Archives and Binary Blazars Studies

    Czech Academy of Sciences Publication Activity Database

    Hudec, René

    2011-01-01

    Roč. 32, 1-2 (2011), s. 91-95 ISSN 0250-6335. [Conference on Multiwavelength Variability of Blazars. Guangzhou, 22,09,2010-24,09,2010] R&D Projects: GA ČR GA205/08/1207 Grant - others:GA ČR(CZ) GA102/09/0997; MŠMT(CZ) ME09027 Institutional research plan: CEZ:AV0Z10030501 Keywords : astronomical plates * plate archives archives * binary blazars Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 0.400, year: 2011

  6. Generating quality tetrahedral meshes from binary volumes

    DEFF Research Database (Denmark)

    Hansen, Mads Fogtmann; Bærentzen, Jakob Andreas; Larsen, Rasmus

    2010-01-01

    use these measures to generate high quality meshes from signed distance maps. This paper also describes an approach for computing (smooth) signed distance maps from binary volumes as volumetric data in many cases originate from segmentation of objects from imaging techniques such as CT, MRI, etc...... generation algorithm on four examples (torus, Stanford dragon, brain mask, and pig back) and report the dihedral angle, aspect ratio and radius-edge ratio. Even though, the algorithm incorporates none of the mentioned quality measures in the compression stage it receives a good score for all these measures...

  7. Binary magnetic structures in HoEr

    DEFF Research Database (Denmark)

    Howard, B.K.; Bohr, J.

    1991-01-01

    The magnetic structure of a single crystal of the rare earth random alloy Ho50% Er50% has been investigated by elastic neutron diffraction measurements in the temperature range 120-10 K. Three distinct magnetic phases are identified below the Neel temperature of 104 K. The high-temperature phase...... observed between 104 K and 47.5 K is a binary magnetic structure where the holmium and erbium moments belong to different modulated c-axis spirals. The intermediate-temperature phase between 47.5 K and 35 K is a simple basal plane spiral. Below 35 K, the measurements suggest a ferrimagnetic structure...

  8. WIYN Open Cluster Study: Tidal Interactions in Solar type Binaries

    OpenAIRE

    Meibom, S.; Mathieu, R. D.

    2003-01-01

    We present an ongoing study on tidal interactions in late-type close binary stars. New results on tidal circularization are combined with existing data to test and constrain theoretical predictions of tidal circularization in the pre-main-sequence (PMS) phase and throughout the main-sequence phase of stellar evolution. Current data suggest that tidal circularization during the PMS phase sets the tidal cutoff period for binary populations younger than ~1 Gyr. Binary populations older than ~1 G...

  9. Optimal static and dynamic recycling of defective binary devices

    Science.gov (United States)

    Challet, Damien; Pérez Castillo, Isaac

    2004-11-01

    The binary defect combination problem consists in finding a fully working subset from a given ensemble of imperfect binary components. We determine the typical properties of the model using methods of statistical mechanics, in particular the region in the parameter space where there is almost surely at least one fully working subset. Dynamic recycling of a flux of imperfect binary components leads to zero wastage.

  10. CNN-aware Binary Map for General Semantic Segmentation

    OpenAIRE

    Ravanbakhsh, Mahdyar; Mousavi, Hossein; Nabi, Moin; Rastegari, Mohammad; Regazzoni, Carlo

    2016-01-01

    In this paper we introduce a novel method for general semantic segmentation that can benefit from general semantics of Convolutional Neural Network (CNN). Our segmentation proposes visually and semantically coherent image segments. We use binary encoding of CNN features to overcome the difficulty of the clustering on the high-dimensional CNN feature space. These binary codes are very robust against noise and non-semantic changes in the image. These binary encoding can be embedded into the CNN...

  11. Detection of Contact Binaries Using Sparse High Phase Angle Lightcurves

    OpenAIRE

    Lacerda, Pedro

    2007-01-01

    We show that candidate contact binary asteroids can be efficiently identified from sparsely sampled photometry taken at phase angles >60deg. At high phase angle, close/contact binary systems produce distinctive lightcurves that spend most of the time at maximum or minimum (typically >1mag apart) brightness with relatively fast transitions between the two. This means that a few (~5) sparse observations will suffice to measure the large range of variation and identify candidate contact binary s...

  12. Search for forced oscillations in binaries. 4. The eclipsing binary V436 Per revisited

    Czech Academy of Sciences Publication Activity Database

    Janík, J.; Harmanec, Petr; Lehmann, H.; Yang, S.; Božić, H.; Ak, H.; Hadrava, Petr; Eenens, P.; Ruždjak, D.; Sudar, D.; Hubený, I.; Linnell, A. P.

    2003-01-01

    Roč. 408, č. 2 (2003), s. 611-619 ISSN 0004-6361 R&D Projects: GA ČR GA205/96/0162; GA AV ČR KSK2043105 Institutional research plan: CEZ:AV0Z1003909 Keywords : binaries stars * eclipsing * spectroscopic Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 3.843, year: 2003

  13. Absolute Dimensions of Contact Binary Stars in Baade Window

    Directory of Open Access Journals (Sweden)

    Young Woon Kang

    1999-12-01

    Full Text Available The light curves of the representative 6 contact binary stars observed by OGLE Project of searching for dark matter in our Galaxy have been analyzed by the method of the Wilson and Devinney Differential Correction to find photometric solutions. The orbital inclinations of these binaries are in the range of 52 deg - 69 deg which is lower than that of the solar neighborhood binaries. The Roche lobe filling factor of these binaries are distributed in large range of 0.12 - 0.90. Since absence of spectroscopic observations for these binaries we have found masses of the 6 binary systems based on the intersection between Kepler locus and locus derived from Vandenberg isochrones in the mass - luminosity plane. Then absolute dimensions and distances have been found by combining the masses and the photometric solutions. The distances of the 6 binary systems are distributed in the range of 1 kpc - 6 kpc. This distance range is the limiting range where the contact binaries which have period shorter than a day are visible. Most contact binaries discovered in the Baade window do not belong to the Galactic bulge.

  14. Inferences about binary stellar populations using gravitational wave observations

    Science.gov (United States)

    Wysocki, Daniel; Gerosa, Davide; O'Shaughnessy, Richard; Belczynski, Krzysztof; Gladysz, Wojciech; Berti, Emanuele; Kesden, Michael; Holz, Daniel

    2018-01-01

    With the dawn of gravitational wave astronomy, enabled by the LIGO and Virgo interferometers, we now have a new window into the Universe. In the short time these detectors have been in use, multiple confirmed detections of gravitational waves from compact binary coalescences have been made. Stellar binary systems are one of the likely progenitors of the observed compact binary sources. If this is indeed the case, then we can use measured properties of these binary systems to learn about their progenitors. We will discuss the Bayesian framework in which we make these inferences, and results which include mass and spin distributions.

  15. Modern geothermal power: Binary cycle geothermal power plants

    Science.gov (United States)

    Tomarov, G. V.; Shipkov, A. A.

    2017-04-01

    In the second part of the review of modern geothermal power plant technologies and equipment, a role, a usage scale, and features of application of binary cycle plants in the geothermal economy are considered. Data on the use of low-boiling fluids, their impact on thermal parameters and performance of geothermal binary power units are presented. A retrospective of the use of various low-boiling fluids in industrial binary power units in the world since 1965 is shown. It is noted that the current generating capacity of binary power units running on hydrocarbons is equal to approximately 82.7% of the total installed capacity of all the binary power units in the world. At the same time over the past 5 years, the total installed capacity of geothermal binary power units in 25 countries increased by more than 50%, reaching nearly 1800 MW (hereinafter electric power is indicated), by 2015. A vast majority of the existing binary power plants recovers heat of geothermal fluid in the range of 100-200°C. Binary cycle power plants have an average unit capacity of 6.3 MW, 30.4 MW at single-flash power plants, 37.4 MW at double-flash plants, and 45.4 MW at power plants working on superheated steam. The largest binary cycle geothermal power plants (GeoPP) with an installed capacity of over 60 MW are in operation in the United States and the Philippines. In most cases, binary plants are involved in the production process together with a steam cycle. Requirements to the fluid ensuring safety, reliability, and efficiency of binary power plants using heat of geothermal fluid are determined, and differences and features of their technological processes are shown. Application of binary cycle plants in the technological process of combined GeoPPs makes it possible to recover geothermal fluid more efficiently. Features and advantages of binary cycle plants using multiple fluids, including a Kalina Cycle, are analyzed. Technical characteristics of binary cycle plants produced by various

  16. An Economic Evaluation of Binary Cycle Geothermal Electricity Production

    National Research Council Canada - National Science Library

    Fitzgerald, Crissie

    2003-01-01

    .... Variables such as well flow rate, geothermal gradient and electricity prices were varied to study their influence on the economic payback period for binary cycle geothermal electricity production...

  17. Improving geothermal power plants with a binary cycle

    Science.gov (United States)

    Tomarov, G. V.; Shipkov, A. A.; Sorokina, E. V.

    2015-12-01

    The recent development of binary geothermal technology is analyzed. General trends in the introduction of low-temperature geothermal sources are summarized. The use of single-phase low-temperature geothermal fluids in binary power plants proves possible and expedient. The benefits of power plants with a binary cycle in comparison with traditional systems are shown. The selection of the working fluid is considered, and the influence of the fluid's physicochemical properties on the design of the binary power plant is discussed. The design of binary power plants is based on the chemical composition and energy potential of the geothermal fluids and on the landscape and climatic conditions at the intended location. Experience in developing a prototype 2.5 MW Russian binary power unit at Pauzhetka geothermal power plant (Kamchatka) is outlined. Most binary systems are designed individually for a specific location. Means of improving the technology and equipment at binary geothermal power plants are identified. One option is the development of modular systems based on several binary systems that employ the heat from the working fluid at different temperatures.

  18. TIDAL INTERACTIONS IN MERGING WHITE DWARF BINARIES

    International Nuclear Information System (INIS)

    Piro, Anthony L.

    2011-01-01

    The recently discovered system J0651 is the tightest known detached white dwarf (WD) binary. Since it has not yet initiated Roche-lobe overflow, it provides a relatively clean environment for testing our understanding of tidal interactions. I investigate the tidal heating of each WD, parameterized in terms of its tidal Q parameter. Assuming that the heating can be radiated efficiently, the current luminosities are consistent with Q 1 ∼ 7 x 10 10 and Q 2 ∼ 2 x 10 7 , for the He and C/O WDs, respectively. Conversely, if the observed luminosities are merely from the cooling of the WDs, these estimated values of Q represent the upper limits. A large Q 1 for the He WD means its spin velocity will be slower than that expected if it was tidally locked, which, since the binary is eclipsing, may be measurable via the Rossiter-McLaughlin effect. After one year, gravitational wave emission shifts the time of eclipses by 5.5 s, but tidal interactions cause the orbit to shrink more rapidly, changing the time by up to an additional 0.3 s after a year. Future eclipse timing measurements may therefore infer the degree of tidal locking.

  19. Structure Defect Property Relationships in Binary Intermetallics

    Science.gov (United States)

    Medasani, Bharat; Ding, Hong; Chen, Wei; Persson, Kristin; Canning, Andrew; Haranczyk, Maciej; Asta, Mark

    2015-03-01

    Ordered intermetallics are light weight materials with technologically useful high temperature properties such as creep resistance. Knowledge of constitutional and thermal defects is required to understand these properties. Vacancies and antisites are the dominant defects in the intermetallics and their concentrations and formation enthalpies could be computed by using first principles density functional theory and thermodynamic formalisms such as dilute solution method. Previously many properties of the intermetallics such as melting temperatures and formation enthalpies were statistically analyzed for large number of intermetallics using structure maps and data mining approaches. We undertook a similar exercise to establish the dependence of the defect properties in binary intermetallics on the underlying structural and chemical composition. For more than 200 binary intermetallics comprising of AB, AB2 and AB3 structures, we computed the concentrations and formation enthalpies of vacancies and antisites in a small range of stoichiometries deviating from ideal stoichiometry. The calculated defect properties were datamined to gain predictive capabilities of defect properties as well as to classify the intermetallics for their suitability in high-T applications. Supported by the US DOE under Contract No. DEAC02-05CH11231 under the Materials Project Center grant (Award No. EDCBEE).

  20. GRAVITATIONAL MEMORY IN BINARY BLACK HOLE MERGERS

    International Nuclear Information System (INIS)

    Pollney, Denis; Reisswig, Christian

    2011-01-01

    In addition to the dominant oscillatory gravitational wave signals produced during binary inspirals, a non-oscillatory component arises from the nonlinear 'memory' effect, sourced by the emitted gravitational radiation. The memory grows significantly during the late-inspiral and merger, modifying the signal by an almost step-function profile, and making it difficult to model by approximate methods. We use numerical evolutions of binary black holes (BHs) to evaluate the nonlinear memory during late-inspiral, merger, and ringdown. We identify two main components of the signal: the monotonically growing portion corresponding to the memory, and an oscillatory part which sets in roughly at the time of merger and is due to the BH ringdown. Counterintuitively, the ringdown is most prominent for models with the lowest total spin. Thus, the case of maximally spinning BHs anti-aligned to the orbital angular momentum exhibits the highest signal-to-noise ratio (S/N) for interferometric detectors. The largest memory offset, however, occurs for highly spinning BHs, with an estimated value of h tot 20 ≅ 0.24 in the maximally spinning case. These results are central to determining the detectability of nonlinear memory through pulsar timing array measurements.

  1. Binary Polymer Brushes of Strongly Immiscible Polymers.

    Science.gov (United States)

    Chu, Elza; Babar, Tashnia; Bruist, Michael F; Sidorenko, Alexander

    2015-06-17

    The phenomenon of microphase separation is an example of self-assembly in soft matter and has been observed in block copolymers (BCPs) and similar materials (i.e., supramolecular assemblies (SMAs) and homo/block copolymer blends (HBCs)). In this study, we use microphase separation to construct responsive polymer brushes that collapse to generate periodic surfaces. This is achieved by a chemical reaction between the minor block (10%, poly(4-vinylpyridine)) of the block copolymer and a substrate. The major block of polystyrene (PS) forms mosaic-like arrays of grafted patches that are 10-20 nm in size. Depending on the nature of the assembly (SMA, HBC, or neat BCP) and annealing method (exposure to vapors of different solvents or heating above the glass transition temperature), a range of "mosaic" brushes with different parameters can be obtained. Successive grafting of a secondary polymer (polyacrylamide, PAAm) results in the fabrication of binary polymer brushes (BPBs). Upon being exposed to specific selective solvents, BPBs may adopt different conformations. The surface tension and adhesion of the binary brush are governed by the polymer occupying the top stratum. The "mosaic" brush approach allows for a combination of strongly immiscible polymers in one brush. This facilitates substantial contrast in the surface properties upon switching, previously only possible for substrates composed of predetermined nanostructures. We also demonstrate a possible application of such PS/PAAm brushes in a tunable bioadhesion-bioadhesive (PS on top) or nonbioadhesive (PAAm on top) surface as revealed by Escherichia coli bacterial seeding.

  2. Multilevel Cross-Dependent Binary Longitudinal Data

    KAUST Repository

    Serban, Nicoleta

    2013-10-16

    We provide insights into new methodology for the analysis of multilevel binary data observed longitudinally, when the repeated longitudinal measurements are correlated. The proposed model is logistic functional regression conditioned on three latent processes describing the within- and between-variability, and describing the cross-dependence of the repeated longitudinal measurements. We estimate the model components without employing mixed-effects modeling but assuming an approximation to the logistic link function. The primary objectives of this article are to highlight the challenges in the estimation of the model components, to compare two approximations to the logistic regression function, linear and exponential, and to discuss their advantages and limitations. The linear approximation is computationally efficient whereas the exponential approximation applies for rare events functional data. Our methods are inspired by and applied to a scientific experiment on spectral backscatter from long range infrared light detection and ranging (LIDAR) data. The models are general and relevant to many new binary functional data sets, with or without dependence between repeated functional measurements.

  3. ACOUSTIC EFFECTS ON BINARY AEROELASTICITY MODEL

    Directory of Open Access Journals (Sweden)

    Kok Hwa Yu

    2011-10-01

    Full Text Available Acoustics is the science concerned with the study of sound. The effects of sound on structures attract overwhelm interests and numerous studies were carried out in this particular area. Many of the preliminary investigations show that acoustic pressure produces significant influences on structures such as thin plate, membrane and also high-impedance medium like water (and other similar fluids. Thus, it is useful to investigate the structure response with the presence of acoustics on aircraft, especially on aircraft wings, tails and control surfaces which are vulnerable to flutter phenomena. The present paper describes the modeling of structural-acoustic interactions to simulate the external acoustic effect on binary flutter model. Here, the binary flutter model which illustrated as a rectangular wing is constructed using strip theory with simplified unsteady aerodynamics involving flap and pitch degree of freedom terms. The external acoustic excitation, on the other hand, is modeled using four-node quadrilateral isoparametric element via finite element approach. Both equations then carefully coupled and solved using eigenvalue solution. The mentioned approach is implemented in MATLAB and the outcome of the simulated result are later described, analyzed and illustrated in this paper.

  4. Binary rf pulse compression experiment at SLAC

    International Nuclear Information System (INIS)

    Lavine, T.L.; Spalek, G.; Farkas, Z.D.; Menegat, A.; Miller, R.H.; Nantista, C.; Wilson, P.B.

    1990-06-01

    Using rf pulse compression it will be possible to boost the 50- to 100-MW output expected from high-power microwave tubes operating in the 10- to 20-GHz frequency range, to the 300- to 1000-MW level required by the next generation of high-gradient linacs for linear for linear colliders. A high-power X-band three-stage binary rf pulse compressor has been implemented and operated at the Stanford Linear Accelerator Center (SLAC). In each of three successive stages, the rf pulse-length is compressed by half, and the peak power is approximately doubled. The experimental results presented here have been obtained at low-power (1-kW) and high-power (15-MW) input levels in initial testing with a TWT and a klystron. Rf pulses initially 770 nsec long have been compressed to 60 nsec. Peak power gains of 1.8 per stage, and 5.5 for three stages, have been measured. This corresponds to a peak power compression efficiency of about 90% per stage, or about 70% for three stages, consistent with the individual component losses. The principle of operation of a binary pulse compressor (BPC) is described in detail elsewhere. We recently have implemented and operated at SLAC a high-power (high-vacuum) three-stage X-band BPC. First results from the high-power three-stage BPC experiment are reported here

  5. High-quality binary interactome mapping.

    Science.gov (United States)

    Dreze, Matija; Monachello, Dario; Lurin, Claire; Cusick, Michael E; Hill, David E; Vidal, Marc; Braun, Pascal

    2010-01-01

    Physical interactions mediated by proteins are critical for most cellular functions and altogether form a complex macromolecular "interactome" network. Systematic mapping of protein-protein, protein-DNA, protein-RNA, and protein-metabolite interactions at the scale of the whole proteome can advance understanding of interactome networks with applications ranging from single protein functional characterization to discoveries on local and global systems properties. Since the early efforts at mapping protein-protein interactome networks a decade ago, the field has progressed rapidly giving rise to a growing number of interactome maps produced using high-throughput implementations of either binary protein-protein interaction assays or co-complex protein association methods. Although high-throughput methods are often thought to necessarily produce lower quality information than low-throughput experiments, we have recently demonstrated that proteome-scale interactome datasets can be produced with equal or superior quality than that observed in literature-curated datasets derived from large numbers of small-scale experiments. In addition to performing all experimental steps thoroughly and including all necessary controls and quality standards, careful verification of all interacting pairs and validation tests using independent, orthogonal assays are crucial to ensure the release of interactome maps of the highest possible quality. This chapter describes a high-quality, high-throughput binary protein-protein interactome mapping pipeline that includes these features. Copyright © 2010 Elsevier Inc. All rights reserved.

  6. Binary droplet collision at high Weber number.

    Science.gov (United States)

    Pan, Kuo-Long; Chou, Ping-Chung; Tseng, Yu-Jen

    2009-09-01

    By using the techniques developed for generating high-speed droplets, we have systematically investigated binary droplet collision when the Weber number (We) was increased from the range usually tested in previous studies on the order of 10 to a much larger value of about 5100 for water (a droplet at 23 m/s with a diameter of 0.7 mm). Various liquids were also used to explore the effects of viscosity and surface tension. Specifically, beyond the well-known regimes at moderate We's, which exhibited coalescence, separation, and separation followed by satellite droplets, we found different behaviors showing a fingering lamella, separation after fingering, breakup of outer fingers, and prompt splattering into multiple secondary droplets as We was increased. The critical Weber numbers that mark the boundaries between these impact regimes are identified. The specific impact behaviors, such as fingering and prompt splattering or splashing, share essential similarity with those also observed in droplet-surface impacts, whereas substantial variations in the transition boundaries may result from the disparity of the boundary conditions at impacts. To compare the outcomes of both types of collisions, a simple model based on energy conservation was carried out to predict the maximum diameter of an expanding liquid disk for a binary droplet collision. The results oppose the dominance of viscous drag, as proposed by previous studies, as the main deceleration force to effect a Rayleigh-Taylor instability and ensuing periphery fingers, which may further lead to the formations of satellite droplets.

  7. Pattern formation in phase separating binary mixtures.

    Science.gov (United States)

    Sam, Ebie M; Hayase, Yumino; Auernhammer, Günter K; Vollmer, Doris

    2011-08-07

    We experimentally investigate the interplay of thermodynamics with hydrodynamics during phase separation of (quasi-) binary mixtures. Well defined patterns emerge while slowly crossing the cloud point curve. Depending on the material parameters of the experimental system, two distinct scenarios are observed. In quasi-binary mixtures of methanol-hexane patterns appear before macroscopic phase separation sets in. In course of time the patterns turn faint while the overall turbidity of the sample increases until the mixtures become completely turbid. We attribute this pattern formation to a latent heat induced instability resembling a Rayleigh-Bénard instability. This is confirmed by calorimetric data and an estimate of its Rayleigh number. Mixtures of C(4)E(1)-water doped with decane phase separate under heating. After passing the cloud point curve these mixtures first become homogenously turbid. While clearing up, pattern formation is observed. We attribute this type of pattern formation to an interfacial tension induced Bénard-Marangoni instability. The occurrence of the two scenarios is supported by the relevant dimensionless numbers. This journal is © the Owner Societies 2011

  8. Theoretical Bounds of Direct Binary Search Halftoning.

    Science.gov (United States)

    Liao, Jan-Ray

    2015-11-01

    Direct binary search (DBS) produces the images of the best quality among half-toning algorithms. The reason is that it minimizes the total squared perceived error instead of using heuristic approaches. The search for the optimal solution involves two operations: (1) toggle and (2) swap. Both operations try to find the binary states for each pixel to minimize the total squared perceived error. This error energy minimization leads to a conjecture that the absolute value of the filtered error after DBS converges is bounded by half of the peak value of the autocorrelation filter. However, a proof of the bound's existence has not yet been found. In this paper, we present a proof that shows the bound existed as conjectured under the condition that at least one swap occurs after toggle converges. The theoretical analysis also indicates that a swap with a pixel further away from the center of the autocorrelation filter results in a tighter bound. Therefore, we propose a new DBS algorithm which considers toggle and swap separately, and the swap operations are considered in the order from the edge to the center of the filter. Experimental results show that the new algorithm is more efficient than the previous algorithm and can produce half-toned images of the same quality as the previous algorithm.

  9. Inverse halftoning using binary permutation filters.

    Science.gov (United States)

    Kim, Y T; Arce, G R; Grabowski, N

    1995-01-01

    The problem of reconstructing a continuous-tone image given its ordered dithered halftone or its error-diffused halftone image is considered. We develop a modular class of nonlinear filters that can reconstruct the continuous-tone information preserving image details and edges that provide important visual cues. The proposed nonlinear reconstruction algorithms, denoted as binary permutation filters, are based on the space and rank orderings of the halftone samples provided by the multiset permutation of the "on" pixels in a halftone observation window. For a given window size, we obtain a wide range of filters by varying the amount of space-rank ordering information utilized in the estimate. For image reconstructions from ordered dithered halftones, we develop periodically space-varying filters that can account for the periodical nature of the underlying screening process. A class of suboptimal but simpler space-invariant reconstruction filters are also proposed and tested. Constrained LMS type algorithms are employed for the design of reconstruction filters that minimize the reconstruction mean squared error. We present simulations showing that binary permutation filters are modular, robust to image source characteristics, and that they produce high visual quality image reconstruction.

  10. Modeling and analysis of advanced binary cycles

    Energy Technology Data Exchange (ETDEWEB)

    Gawlik, K.

    1997-12-31

    A computer model (Cycle Analysis Simulation Tool, CAST) and a methodology have been developed to perform value analysis for small, low- to moderate-temperature binary geothermal power plants. The value analysis method allows for incremental changes in the levelized electricity cost (LEC) to be determined between a baseline plant and a modified plant. Thermodynamic cycle analyses and component sizing are carried out in the model followed by economic analysis which provides LEC results. The emphasis of the present work is on evaluating the effect of mixed working fluids instead of pure fluids on the LEC of a geothermal binary plant that uses a simple Organic Rankine Cycle. Four resources were studied spanning the range of 265{degrees}F to 375{degrees}F. A variety of isobutane and propane based mixtures, in addition to pure fluids, were used as working fluids. This study shows that the use of propane mixtures at a 265{degrees}F resource can reduce the LEC by 24% when compared to a base case value that utilizes commercial isobutane as its working fluid. The cost savings drop to 6% for a 375{degrees}F resource, where an isobutane mixture is favored. Supercritical cycles were found to have the lowest cost at all resources.

  11. FG-MOS neuron for binary CNN

    Science.gov (United States)

    Flak, Jacek; Laiho, Mika; Halonen, Kari

    2005-06-01

    This paper presents a neuron implementation based on floating-gate MOSFET (FG-MOS) structure. The computation is performed by charge distribution at the input of FG-MOS inverter determining the cell state. There is no current-flow through the interconnections after processing is completed, thus a significant reduction in DC power consumption can be achieved. Such neuron can be used to build a capacitively coupled cellular neural/nonlinear network (CNN) for processing black and white (B/W) images. Although the coupling coefficients are basically implemented with capacitances, this approach provides them with 1-bit programmability. Also the neuron's threshold level can be digitally programmed to four different values. The templates operating on the B/W images can be modified to have only binary-valued {0,1} terms or can be split into such (sequentially run) simple subtasks. Therefore, the presented neuron structure is able to perform the evaluation of almost all B/W templates proposed so far. Exploration of FG-MOS structures can help to understand the implementation problems of capacitively coupled CNNs. Such a situation appears, e.g., in nanoelectronic CNNs composed of single-electron tunneling (SET) transistors, which also deal with B/W images only. Moreover, the binary programmability approach utilized here should help to develop an effective programming scheme for future SET or CMOS-SET hybrid CNN implementations. Along with the neuron structure, its operation description and simulation results of the 8 x 8 network are presented.

  12. Backyard Telescopes Watch an Expanding Binary

    Science.gov (United States)

    Kohler, Susanna

    2018-01-01

    What can you do with a team of people armed with backyard telescopes and a decade of patience? Test how binary star systems evolve under Einsteins general theory of relativity!Unusual VariablesCataclysmic variables irregularly brightening binary stars consisting of an accreting white dwarf and a donor star are a favorite target among amateur astronomers: theyre detectable even with small telescopes, and theres a lot we can learn about stellar astrophysics by observing them, if were patient.Diagram of a cataclysmic variable. In an AM CVn, the donor is most likely a white dwarf as well, or a low-mass helium star. [Philip D. Hall]Among the large family of cataclysmic variables is one unusual type: the extremely short-period AM Canum Venaticorum (AM CVn) stars. These rare variables (only 40 are known) are unique in having spectra dominated by helium, suggesting that they contain little or no hydrogen. Because of this, scientists have speculated that the donor stars in these systems are either white dwarfs themselves or very low-mass helium stars.Why study AM CVn stars? Because their unusual configuration allows us to predict the behavior of their orbital evolution. According to the general theory of relativity, the two components of an AM CVn will spiral closer and closer as the system loses angular momentum to gravitational-wave emission. Eventually they will get so close that the low-mass companion star overflows its Roche lobe, beginning mass transfer to the white dwarf. At this point, the orbital evolution will reverse and the binary orbit will expand, increasing its period.CBA member Enrique de Miguel, lead author on the study, with his backyard telescope in Huelva, Spain. [Enrique de Miguel]Backyard Astronomy Hard at WorkMeasuring the evolution of an AM CVns orbital period is the best way to confirm this model, but this is no simple task! To observe this evolution, we first need a system with a period that can be very precisely measured best achieved with an

  13. LIGO Finds Lightest Black-Hole Binary

    Science.gov (United States)

    Kohler, Susanna

    2017-11-01

    Wednesdayevening the Laser Interferometer Gravitational-wave Observatory (LIGO) collaboration quietly mentioned that theyd found gravitational waves from yet another black-hole binary back in June. This casual announcement reveals what is so far the lightest pair of black holes weve watched merge opening the door for comparisons to the black holes weve detected by electromagnetic means.A Routine DetectionThe chirp signal of GW170608 detected by LIGO Hanford and LIGO Livingston. [LIGO collaboration 2017]After the fanfare of the previous four black-hole-binary merger announcements over the past year and a half as well as the announcement of the one neutron-star binary merger in August GW170608 marks our entry into the era in which gravitational-wave detections are officially routine.GW170608, a gravitational-wave signal from the merger of two black holes roughly a billion light-years away, was detected in June of this year. This detection occurred after wed already found gravitational waves from several black-hole binaries with the two LIGO detectors in the U.S., but before the Virgo interferometer came online in Europe and increased the joint ability of the detectors to localize sources.Mass estimates for the two components of GW170608 using different models. [LIGO collaboration 2017]Overall, GW170608 is fairly unremarkable: it was detected by both LIGO Hanford and LIGO Livingston some 7 ms apart, and the signal looks not unlike those of the previous LIGO detections. But because were still in the early days of gravitational-wave astronomy, every discovery is still remarkable in some way! GW170608 stands out as being the lightest pair of black holes weve yet to see merge, with component masses before the merger estimated at 12 and 7 times the mass of the Sun.Why Size MattersWith the exception of GW151226, the gravitational-wave signal discovered on Boxing Day last year, all of the black holes that have been discovered by LIGO/Virgo have been quite large: the masses

  14. Binary to Octal and Octal to Binary Code Converter Using Mach-Zehnder Interferometer for High Speed Communication

    Science.gov (United States)

    Pal, Amrindra; Kumar, Santosh; Sharma, Sandeep

    2017-05-01

    Binary to octal and octal to binary code converter is a device that allows placing digital information from many inputs to many outputs. Any application of combinational logic circuit can be implemented by using external gates. In this paper, binary to octal and octal to binary code converter is proposed using electro-optic effect inside lithium-niobate based Mach-Zehnder interferometers (MZIs). The MZI structures have powerful capability to switching an optical input signal to a desired output port. The paper constitutes a mathematical description of the proposed device and thereafter simulation using MATLAB. The study is verified using beam propagation method (BPM).

  15. Perceptual biases for rhythm: The Mismatch Negativity latency indexes the privileged status of binary vs non-binary interval ratios.

    Science.gov (United States)

    Pablos Martin, X; Deltenre, P; Hoonhorst, I; Markessis, E; Rossion, B; Colin, C

    2007-12-01

    Rhythm perception appears to be non-linear as human subjects are better at discriminating, categorizing and reproducing rhythms containing binary vs non-binary (e.a. 1:2 vs 1:3) as well as metrical vs non-metrical (e.a. 1:2 vs 1:2.5) interval ratios. This study examined the representation of binary and non-binary interval ratios within the sensory memory, thus yielding a truly sensory, pre-motor, attention-independent neural representation of rhythmical intervals. Five interval ratios, one binary, flanked by four non-binary ones, were compared on the basis of the MMN they evoked when contrasted against a common standard interval. For all five intervals, the larger the contrast was, the larger the MMN amplitude was. The binary interval evoked a significantly much shorter (by at least 23 ms) MMN latency than the other intervals, whereas no latency difference was observed between the four non-binary intervals. These results show that the privileged perceptual status of binary rhythmical intervals is already present in the sensory representations found in echoic memory at an early, automatic, pre-perceptual and pre-motor level. MMN latency can be used to study rhythm perception at a truly sensory level, without any contribution from the motor system.

  16. Squeezing-enhanced phase-shift-keyed binary communication in noisy channels

    Science.gov (United States)

    Chesi, Giovanni; Olivares, Stefano; Paris, Matteo G. A.

    2018-03-01

    We address binary phase-shift-keyed communication channels based on Gaussian states and prove that squeezing improves state discrimination at fixed energy of the channel, and also in the presence of phase diffusion. We then assess performances of homodyne detection against the ultimate quantum limits to discrimination and show that homodyning achieves optimality in the large-noise regime. Finally, we consider noise in the preparation of the seed signal (before phase encoding) and show that, also in this case, squeezing may improve state discrimination in realistic conditions.

  17. Study of solid-state stability of the ZOTO binary system

    OpenAIRE

    WAGHULEY, Sandeep Anandrao

    2013-01-01

    The ZOTO binary system contains different compositions of zinc oxide (ZnO) and tin oxide (SnO2). These are important semiconductors and have been intensively explored for various applications. SnO2, ZnO, and different mole ratios (70:30, 40:60, 30:70, and 20:80 SnO2:ZnO) of the ZOTO system were prepared through proper thermal treatment in powder form. The comparative solid-state stability was investigated using thermogravimetric and differential thermal analysis (TG-DTA). The stabi...

  18. MARVELS Radial Velocity Solutions to Seven Kepler Eclipsing Binaries

    Science.gov (United States)

    Heslar, Michael Francis; Thomas, Neil B.; Ge, Jian; Ma, Bo; Herczeg, Alec; Reyes, Alan; SDSS-III MARVELS Team

    2016-01-01

    Eclipsing binaries serve momentous purposes to improve the basis of understanding aspects of stellar astrophysics, such as the accurate calculation of the physical parameters of stars and the enigmatic mass-radius relationship of M and K dwarfs. We report the investigation results of 7 eclipsing binary candidates, initially identified by the Kepler mission, overlapped with the radial velocity observations from the SDSS-III Multi-Object APO Radial-Velocity Exoplanet Large-Area Survey (MARVELS). The RV extractions and spectroscopic solutions of these eclipsing binaries were generated by the University of Florida's 1D data pipeline with a median RV precision of ~60-100 m/s, which was utilized for the DR12 data release. We performed the cross-reference fitting of the MARVELS RV data and the Kepler photometric fluxes obtained from the Kepler Eclipsing Binary Catalog (V2) and modelled the 7 eclipsing binaries in the BinaryMaker3 and PHOEBE programs. This analysis accurately determined the absolute physical and orbital parameters of each binary. Most of the companion stars were determined to have masses of K and M dwarf stars (0.3-0.8 M⊙), and allowed for an investigation into the mass-radius relationship of M and K dwarfs. Among the cases are KIC 9163796, a 122.2 day period "heartbeat star", a recently-discovered class of eccentric binaries known for tidal distortions and pulsations, with a high eccentricity (e~0.75) and KIC 11244501, a 0.29 day period, contact binary with a double-lined spectrum and mass ratio (q~0.45). We also report on the possible reclassification of 2 Kepler eclipsing binary candidates as background eclipsing binaries based on the analysis of the flux measurements, flux ratios of the spectroscopic and photometric solutions, the differences in the FOVs, the image processing of Kepler, and RV and spectral analysis of MARVELS.

  19. Study of component distribution in pharmaceutical binary powder mixtures by near infrared chemical imaging

    Directory of Open Access Journals (Sweden)

    Manel Bautista

    2012-12-01

    Full Text Available Near infrared chemical imaging (NIR-CI has recently emerged as an effective technique for extracting spatial information from pharmaceutical products in an expeditious, non-destructive and non-invasive manner. These features have turned it into a useful tool for controlling various steps in drug production processes. Imaging techniques provide a vast amount of both spatial and spectral information that can be acquired in a very short time. Such a huge amount of data requires the use of efficient and fast methods to extract the relevant information. Chemometric methods have proved especially useful for this purpose. In this study, we assessed the usefulness of the correlation coefficient (CC between the spectra of samples, the pure spectra of the active pharmaceutical ingredient (API and we assessed the excipients to check for correct ingredient distribution in pharmaceutical binary preparations blended in the laboratory. Visual information about pharmaceutical component distribution can be obtained by using the CC. The performance of this model construction methodology for binary samples was compared with other various common multivariate methods including partial least squares, multivariate curve resolution and classical least squares. Based on the results, correlation coefficients are a powerful tool for the rapid assessment of correct component distribution and for quantitative analysis of pharmaceutical binary formulations. For samples of three or more components it has been shown that if the objective is only to determine uniformity of blending, then the CC image map is very good for this, and easy and fast to compute.

  20. Organometallic Routes into the Nanorealms of Binary Fe-Si Phases

    Directory of Open Access Journals (Sweden)

    Teddy M. Keller

    2010-02-01

    Full Text Available The Fe-Si binary system provides several iron silicides that have varied and exceptional material properties with applications in the electronic industry. The well known Fe-Si binary silicides are Fe3Si, Fe5Si3, FeSi, a-FeSi2 and b-FeSi2. While the iron-rich silicides Fe3Si and Fe5Si3 are known to be room temperature ferromagnets, the stoichiometric FeSi is the only known transition metal Kondo insulator. Furthermore, Fe5Si3 has also been demonstrated to exhibit giant magnetoresistance (GMR. The silicon-rich b-FeSi2 is a direct band gap material usable in light emitting diode (LED applications. Typically, these silicides are synthesized by traditional solid-state reactions or by ion beam-induced mixing (IBM of alternating metal and silicon layers. Alternatively, the utilization of organometallic compounds with reactive transition metal (Fe-carbon bonds has opened various routes for the preparation of these silicides and the silicon-stabilized bcc- and fcc-Fe phases contained in the Fe-Si binary phase diagram. The unique interfacial interactions of carbon with the Fe and Si components have resulted in the preferential formation of nanoscale versions of these materials. This review will discuss such reactions.

  1. Biomimetic superhydrophobic surface of high adhesion fabricated with micronano binary structure on aluminum alloy.

    Science.gov (United States)

    Liu, Yan; Liu, Jindan; Li, Shuyi; Liu, Jiaan; Han, Zhiwu; Ren, Luquan

    2013-09-25

    Triggered by the microstructure characteristics of the surfaces of typical plant leaves such as the petals of red roses, a biomimetic superhydrophobic surface with high adhesion is successfully fabricated on aluminum alloy. The essential procedure is that samples were processed by a laser, then immersed and etched in nitric acid and copper nitrate, and finally modified by DTS (CH3(CH2)11Si(OCH3)3). The obtained surfaces exhibit a binary structure consisting of microscale crater-like pits and nanoscale reticula. The superhydrophobicity can be simultaneously affected by the micronano binary structure and chemical composition of the surface. The contact angle of the superhydrophobic surface reaches up to 158.8 ± 2°. Especially, the surface with micronano binary structure is revealed to be an excellent adhesive property with petal-effect. Moreover, the superhydrophobic surfaces show excellent stability in aqueous solution with a large pH range and after being exposed long-term in air. In this way, the multifunctional biomimetic structural surface of the aluminum alloy is fabricated. Furthermore, the preparation technology in this article provides a new route for other metal materials.

  2. Organometallic Routes into the Nanorealms of Binary Fe-Si Phases

    Science.gov (United States)

    Kolel-Veetil, Manoj K.; Keller, Teddy M.

    2010-01-01

    The Fe-Si binary system provides several iron silicides that have varied and exceptional material properties with applications in the electronic industry. The well known Fe-Si binary silicides are Fe3Si, Fe5Si3, FeSi, α-FeSi2 and β-FeSi2. While the iron-rich silicides Fe3Si and Fe5Si3 are known to be room temperature ferromagnets, the stoichiometric FeSi is the only known transition metal Kondo insulator. Furthermore, Fe5Si3 has also been demonstrated to exhibit giant magnetoresistance (GMR). The silicon-rich β-FeSi2 is a direct band gap material usable in light emitting diode (LED) applications. Typically, these silicides are synthesized by traditional solid-state reactions or by ion beam-induced mixing (IBM) of alternating metal and silicon layers. Alternatively, the utilization of organometallic compounds with reactive transition metal (Fe)-carbon bonds has opened various routes for the preparation of these silicides and the silicon-stabilized bcc- and fcc-Fe phases contained in the Fe-Si binary phase diagram. The unique interfacial interactions of carbon with the Fe and Si components have resulted in the preferential formation of nanoscale versions of these materials. This review will discuss such reactions.

  3. Programmable spectral design and the binary supergrating

    Science.gov (United States)

    Levner, Daniel

    Spectral operations such as wavelength selection, power level manipulation, and chromatic dispersion control are key to many processes in optical telecommunication, spectroscopy, and sensing. In their simplest forms, these functions can be performed using a number of successful devices such as the Fraunhofer ("diffraction") grating, Bragg grating, thin-film filter (TFF), and dispersion-compensating fiber (DCF). More complicated manipulations, however, often require either problematic cascades of many simple elements, the use of custom technologies that offer little adjustment, or the implementation of fully programmable devices, which allow for the desired spectral function to be synthesized ab initio. Here, I present the Binary Supergrating (BSG), a novel technology that permits the programmable and near-arbitrary control of optical amplitude and phase using a simple, robust and practical form. This guided-wave form consists of an aperiodic sequence of binary elements; the sequence, determined through the process of BSG synthesis, encodes an optical program that defines device functionality. The ability to derive optical programs that address broad spectral demands is central to the BSG's extensive capabilities. In consequence, I present a powerful approach to synthesis that exploits existing knowledge in the design of "analog" gratings. This approach is based on a two-step process, which first derives an analog diffractive structure using the best available methods and then transforms it into binary form. Accordingly, I discuss the notion of diffractive structure transformation and introduce the principle of key information. I identify such key information and illustrate its application in grating quantizers based on an atypical form of Delta-Sigma modulation. As a digital approach to spectral engineering, the BSG presents many of the same advantages offered by the digital approach to electronic signal processing (DSP) over its analog predecessors. As such, it

  4. Preparation and Characterization of Acrylonitrile Copolymers by Emulsion Technique

    International Nuclear Information System (INIS)

    El-Halawany, N.R.; Abd El-Ghaffar, M.A.; Mokhtar, S.M.

    2005-01-01

    Acrylonitrile (AN) binary copolymers with styrene (St) and maleic acid (MA) of different compositions were prepared by free radical emulsion copolymerization using potassium persulfate and sodium bisulfite as a redox pair initiation system and sodium dodecyl benzene sulfonate as an emulsifier. Based on the copolymerization data of the (AN/St) and (AN/MA) in emulsion polymerization process, the reactivity ratios of the prepared copolymers were investigated by different methods. Thermogravimetric analysis and X-ray diffraction were studied to characterize the prepared copolymers. Physicomechanical properties of some copolymeric lattices films were also identified

  5. Binary classification posed as a quadratically constrained quadratic ...

    Indian Academy of Sciences (India)

    DEEPAK KUMAR

    Binary classification is one of the active research areas in machine learning [4, 5]. There are several ways to train a binary classifier. The features and the class labels of the training data set can be stored and retrieved during classifica- tion using the nearest neighbor approach [6]. A hyperplane is learnt for classification by ...

  6. Neutron Stars in X-ray Binaries and their Environments

    Indian Academy of Sciences (India)

    The X-ray pulsars among the binary neutron stars provide excellent handle to make accurate measurement of the orbital parameters and thus also evolution of the binray orbits that take place over time scale of a fraction of a million years to tens of millions of years. The orbital period evolution of X-ray binaries have shown ...

  7. Phase separation in binary hard-core mixtures

    NARCIS (Netherlands)

    Dijkstra, Marjolein; Frenkel, D.; Hansen, J.-P.

    1994-01-01

    We report the observation of a purely entropic demixing transition in a three-dimensional binary hard-core mixture by computer simulations. This transition is observed in a lattice model of a binary hard-core mixture of parallel cubes provided that the size asymmetry of the large and small particles

  8. Research note : Miscibility behaviour of binary mixtures of benzyl ...

    African Journals Online (AJOL)

    Miscibility of binary mixtures of benzyl benzoate and liquid paraffin as functions of temperature and composition has been determined using phase separation method. The binary mixtures demonstrated a critical (upper) solution temperature of 35 °C at 101325 Nm-2 with a mixing gap. A tie-line drawn at 28 °C across the ...

  9. Progenitor models of Wolf-Rayet+O binary systems

    NARCIS (Netherlands)

    Petrovic, J.; Langer, N.

    2007-01-01

    Since close WR+O binaries are the result of a strong interaction of both stars in massive close binary systems, they can be used to constrain the highly uncertain mass and angular momentum budget during the major mass- transfer phase. We explore the progenitor evolution of the three best suited WR+O

  10. Grammar-Based Specification and Parsing of Binary File Formats

    Directory of Open Access Journals (Sweden)

    William Underwood

    2012-03-01

    Full Text Available The capability to validate and view or play binary file formats, as well as to convert binary file formats to standard or current file formats, is critically important to the preservation of digital data and records. This paper describes the extension of context-free grammars from strings to binary files. Binary files are arrays of data types, such as long and short integers, floating-point numbers and pointers, as well as characters. The concept of an attribute grammar is extended to these context-free array grammars. This attribute grammar has been used to define a number of chunk-based and directory-based binary file formats. A parser generator has been used with some of these grammars to generate syntax checkers (recognizers for validating binary file formats. Among the potential benefits of an attribute grammar-based approach to specification and parsing of binary file formats is that attribute grammars not only support format validation, but support generation of error messages during validation of format, validation of semantic constraints, attribute value extraction (characterization, generation of viewers or players for file formats, and conversion to current or standard file formats. The significance of these results is that with these extensions to core computer science concepts, traditional parser/compiler technologies can potentially be used as a part of a general, cost effective curation strategy for binary file formats.

  11. Formation of Thorne–Żytkow objects in close binaries

    Indian Academy of Sciences (India)

    Bumareyamu Hutilukejiang

    2018-03-06

    Zytkow, may form as a result of unstable mass transfer in a massive X-ray binary after a neutron star (NS) is engulfed in the envelope of its companion star. Using a rapid binary evolution program and the Monte Carlo method, ...

  12. Resonant Tidal Forcing in Close Binaries: Implications for CVs

    Science.gov (United States)

    Ford, K. E. Saavik; McKernan, Barry; Schwab, Elliana

    2018-01-01

    Resonant tidal forcing occurs when the tidal forcing frequency of a binary matches a quadrupolar oscillation mode of one of the binary members and energy is transferred from the orbit of the binary to the mode. Tidal locking permits ongoing resonant driving of modes even as binary orbital parameters change. At small binary separations during tidal lock, a significant fraction of binary orbital energy can be deposited quickly into a resonant mode and the binary decays faster than via the emission of gravitational radiation alone. Here we discuss some of the implications of resonant tidal forcing for the class of binaries known as Cataclysmic Variable (CV) stars. We show that resonant tidal forcing of the donor’s Roche lobe could explain the observed 2‑3hr period gap in CVs, assuming modest orbital eccentricities are allowed (eb ∼ 0.03), and can be complementary or an alternative to, existing models. Sudden collapse of the companion orbit, yielding a Type Ia supernova is disfavoured, since Hydrogen is not observed in Type Ia supernova spectra. Therefore, resonance must generally be truncated, probably via mass loss from the Roche lobe or orbital perturbation, ultimately producing a short period CV containing an ’overheated’ white dwarf.

  13. Lamellar-in-lamellar structure of binary linear multiblock copolymers

    NARCIS (Netherlands)

    Klymko, T.; Subbotin, A.; ten Brinke, G.

    2008-01-01

    A theoretical description of the lamellar-in-lamellar self-assembly of binary A-b-(B-b-A)(m)-b-B-b-A multiblock copolymers in the strong segregation limit is presented. The essential difference between this binary multiblock system and the previously considered C-b-(B-b-A)(m)-b-B-b-C ternary

  14. Binary sequence detector uses minimum number of decision elements

    Science.gov (United States)

    Perlman, M.

    1966-01-01

    Detector of an n bit binary sequence code within a serial binary data system assigns states to memory elements of a code sequence detector by employing the same order of states for the sequence detector as that of the sequence generator when the linear recursion relationship employed by the sequence generator is given.

  15. White dwarf-red dwarf binaries in the Galaxy

    NARCIS (Netherlands)

    Besselaar, E.J.M. van den

    2007-01-01

    This PhD thesis shows several studies on white dwarf - red dwarf binaries. White dwarfs are the end products of most stars and red dwarfs are normal hydrogen burning low-mass stars. White dwarf - red dwarf binaries are both blue (white dwarf) and red (red dwarf). Together with the fact that they are

  16. Binary GCD like Algorithms for Some Complex Quadratic Rings

    DEFF Research Database (Denmark)

    Agarwal, Saurabh; Frandsen, Gudmund Skovbjerg

    2004-01-01

    binary gcd like algorithms for the ring of integers in and , one now has binary gcd like algorithms for all complex quadratic Euclidean domains. The running time of our algorithms is O(n 2) in each ring. While there exists an O(n 2) algorithm for computing the gcd in quadratic number rings by Erich...

  17. Observer bias in randomised clinical trials with binary outcomes

    DEFF Research Database (Denmark)

    Hróbjartsson, Asbjørn; Thomsen, Ann Sofia Skou; Emanuelsson, Frida

    2012-01-01

    To evaluate the impact of non-blinded outcome assessment on estimated treatment effects in randomised clinical trials with binary outcomes.......To evaluate the impact of non-blinded outcome assessment on estimated treatment effects in randomised clinical trials with binary outcomes....

  18. The Cool Surfaces of Binaries Near-Earth Asteroids

    NARCIS (Netherlands)

    Delbo, Marco; Walsh, K.; Mueller, M.

    2008-01-01

    We present results from thermal-infrared observations of binary near-Earth asteroids (NEAs). These objects, in general, have surface temperatures cooler than the average values for non-binary NEAs. We discuss how this may be evidence of higher-than-average surface thermal inertia. The comparison of

  19. Dielectric studies of binary mixtures of -propyl alcohol and ...

    Indian Academy of Sciences (India)

    Dielectric constant (') and dielectric loss (") of -propyl alcohol (PA), ethylenediamine (EDA) and their binary mixtures, for different mole fractions of ethylenediamine have been experimentally measured at 11.15 GHz microwave frequency. Values of density (), viscosity () and square refractive index ( n D 2 ) of binary ...

  20. Thin shell morphology in the circumstellar medium of massive binaries

    NARCIS (Netherlands)

    van Marle, A. J.; Keppens, R.; Meliani, Z.

    2011-01-01

    Context. In massive binaries, the powerful stellar winds of the two stars collide, leading to the formation of shock-dominated environments that can be modeled only in 3D. Aims. We investigate the morphology of the collision-front shell between the stellar winds of binary components in two

  1. Excess molar volumes and isentropic compressibilities of binary ...

    Indian Academy of Sciences (India)

    Excess molar volumes (E) and deviation in isentropic compressibilities (s) have been investigated from the density and speed of sound measurements of six binary liquid mixtures containing -alkanes over the entire range of composition at 298.15 K. Excess molar volume exhibits inversion in sign in one binary ...

  2. Putting Continuous Metaheuristics to Work in Binary Search Spaces

    Directory of Open Access Journals (Sweden)

    Broderick Crawford

    2017-01-01

    Full Text Available In the real world, there are a number of optimization problems whose search space is restricted to take binary values; however, there are many continuous metaheuristics with good results in continuous search spaces. These algorithms must be adapted to solve binary problems. This paper surveys articles focused on the binarization of metaheuristics designed for continuous optimization.

  3. Binary pattern analysis for 3D facial action unit detection

    NARCIS (Netherlands)

    Sandbach, Georgia; Zafeiriou, Stefanos; Pantic, Maja

    2012-01-01

    In this paper we propose new binary pattern features for use in the problem of 3D facial action unit (AU) detection. Two representations of 3D facial geometries are employed, the depth map and the Azimuthal Projection Distance Image (APDI). To these the traditional Local Binary Pattern is applied,

  4. Excess molar volumes and isentropic compressibilities of binary ...

    Indian Academy of Sciences (India)

    and transport properties of n-alkanes and their mixtures. Several workers [1–4] have pre- viously studied excess properties of binary liquid mixtures containing chloroalkanes. In our [5–8] systematic investigation of the thermodynamic, acoustic and transport prop- erties of binary liquid mixtures, we have reported viscosities, ...

  5. IUE observations of the eclipsing binary Epsilon Aurigae

    International Nuclear Information System (INIS)

    Hack, M.; Selvelli, P.L.

    1978-01-01

    It is stated that the eclipsing binary Epsilon Aur is a most peculiar binary system and it has not been explained satisfactorily. Observations of this system using the International Ultraviolet Explorer (IUE) collected at the Villafranca Satellite Tracking Station of the European Space Agency are here reported. (author)

  6. Binary Biometric Representation through Pairwise Adaptive Phase Quantization

    NARCIS (Netherlands)

    Chen, C.; Veldhuis, Raymond N.J.

    Extracting binary strings from real-valued biometric templates is a fundamental step in template compression and protection systems, such as fuzzy commitment, fuzzy extractor, secure sketch, and helper data systems. Quantization and coding is the straightforward way to extract binary representations

  7. First Hα and Revised Photometric Studies of Contact Binary ...

    Indian Academy of Sciences (India)

    Common among the variable stars are the contact binaries which form an excellent source in determining the stellar parameters with high degree of accuracy (Southworth. 2012). These binaries which are also referred to as W Ursae Majoris (W UMa) stars occur when both components of the system fill their Roche lobes ...

  8. Absolute dimensions of eclipsing binaries XXVII. V1130 tauri

    DEFF Research Database (Denmark)

    Clausen, Jens Viggo; Olsen, E, H.; Helt, B. E.

    2010-01-01

    stars: evolution / stars: fundamental parameters / stars: individual: V1130¿Tau / binaries: eclipsing / techniques: photometric / techniques: radial velocities Udgivelsesdato: 17 Feb.......stars: evolution / stars: fundamental parameters / stars: individual: V1130¿Tau / binaries: eclipsing / techniques: photometric / techniques: radial velocities Udgivelsesdato: 17 Feb....

  9. Black Hole/Pulsar Binaries in the Galaxy

    Science.gov (United States)

    Shao, Yong; Li, Xiang-Dong

    2018-04-01

    We have performed population synthesis calculation on the formation of binaries containing a black hole (BH) and a neutron star (NS) in the Galactic disk. Some of important input parameters, especially for the treatment of common envelope evolution, are updated in the calculation. We have discussed the uncertainties from the star formation rate of the Galaxy and the velocity distribution of NS kicks on the birthrate (˜ 0.6-13 Myr^{-1}) of BH/NS binaries. From incident BH/NS binaries, by modelling the orbital evolution duo to gravitational wave radiation and the NS evolution as radio pulsars, we obtain the distributions of the observable parameters such as the orbital period, eccentricity and pulse period of the BH/pulsar binaries. We estimate that there may be ˜3 - 80 BH/pulsar binaries in the Galactic disk and around 10% of them could be detected by the Five-hundred-meter Aperture Spherical radio Telescope.

  10. Orbital motion in pre-main sequence binaries

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, G. H. [The CHARA Array of Georgia State University, Mount Wilson Observatory, Mount Wilson, CA 91023 (United States); Prato, L. [Lowell Observatory, 1400 West Mars Hill Road, Flagstaff, AZ 86001 (United States); Simon, M. [Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794 (United States); Patience, J., E-mail: schaefer@chara-array.org [Astrophysics Group, School of Physics, University of Exeter, Exeter, EX4 4QL (United Kingdom)

    2014-06-01

    We present results from our ongoing program to map the visual orbits of pre-main sequence (PMS) binaries in the Taurus star forming region using adaptive optics imaging at the Keck Observatory. We combine our results with measurements reported in the literature to analyze the orbital motion for each binary. We present preliminary orbits for DF Tau, T Tau S, ZZ Tau, and the Pleiades binary HBC 351. Seven additional binaries show curvature in their relative motion. Currently, we can place lower limits on the orbital periods for these systems; full solutions will be possible with more orbital coverage. Five other binaries show motion that is indistinguishable from linear motion. We suspect that these systems are bound and might show curvature with additional measurements in the future. The observations reported herein lay critical groundwork toward the goal of measuring precise masses for low-mass PMS stars.

  11. Dynamic Inertia Weight Binary Bat Algorithm with Neighborhood Search

    Directory of Open Access Journals (Sweden)

    Xingwang Huang

    2017-01-01

    Full Text Available Binary bat algorithm (BBA is a binary version of the bat algorithm (BA. It has been proven that BBA is competitive compared to other binary heuristic algorithms. Since the update processes of velocity in the algorithm are consistent with BA, in some cases, this algorithm also faces the premature convergence problem. This paper proposes an improved binary bat algorithm (IBBA to solve this problem. To evaluate the performance of IBBA, standard benchmark functions and zero-one knapsack problems have been employed. The numeric results obtained by benchmark functions experiment prove that the proposed approach greatly outperforms the original BBA and binary particle swarm optimization (BPSO. Compared with several other heuristic algorithms on zero-one knapsack problems, it also verifies that the proposed algorithm is more able to avoid local minima.

  12. What fraction of white dwarfs are members of binary systems?

    International Nuclear Information System (INIS)

    Holberg, J B

    2009-01-01

    White dwarfs were originally discovered as the subordinate faint companions of bright nearby stars (i.e. Sirius B and 40 Eri B). Several general categories of binary systems involving white dwarfs are recognized: Sirius-like systems, where the white dwarf may be difficult to detect, binary systems containing white dwarfs and low mass stars, where the white dwarf is often readily discerned; and double degenerate systems. Different modes of white dwarf discovery influence our perception of both the overall binary fraction and the nature of these systems; proper motion surveys emphasize resolved systems, while photometric surveys emphasize unresolved systems containing relatively hot white dwarfs. Recent studies of the local white dwarf population offer some hope of achieving realistic estimates of the relative number of binary systems containing white dwarfs. A sample of 132 white dwarfs within 20 pc indicates that an individual white dwarf has a probability of 32 ± 8% of occurring within a binary or multiple star system.

  13. A binary electrolyte model of a cylindrical alkaline cell

    Science.gov (United States)

    Kriegsmann, J. J.; Cheh, H. Y.

    A cylindrical alkaline cell is modeled as a binary electrolyte system by assuming the direct electrochemical formation of ZnO in the anode. Justifications for replacing the dissolution-precipitation mechanism are provided. Compared to the original model, the binary electrolyte model has a more understandable model formulation, more consistent physical property data, and greater flexibility in certain instances. The binary electrolyte model predicts a longer cell life and higher operating voltage than the ternary electrolyte model for the test case discharge rate. There are no numerical difficulties associated with the zincate ion in the binary electrolyte model, because this species is not considered. The characteristics and advantages of the simplified anode behavior are discussed. An application of the binary electrolyte model is included.

  14. Binary classification of items of interest in a repeatable process

    Science.gov (United States)

    Abell, Jeffrey A.; Spicer, John Patrick; Wincek, Michael Anthony; Wang, Hui; Chakraborty, Debejyo

    2014-06-24

    A system includes host and learning machines in electrical communication with sensors positioned with respect to an item of interest, e.g., a weld, and memory. The host executes instructions from memory to predict a binary quality status of the item. The learning machine receives signals from the sensor(s), identifies candidate features, and extracts features from the candidates that are more predictive of the binary quality status relative to other candidate features. The learning machine maps the extracted features to a dimensional space that includes most of the items from a passing binary class and excludes all or most of the items from a failing binary class. The host also compares the received signals for a subsequent item of interest to the dimensional space to thereby predict, in real time, the binary quality status of the subsequent item of interest.

  15. Non-negative Matrix Factorization for Binary Data

    DEFF Research Database (Denmark)

    Larsen, Jacob Søgaard; Clemmensen, Line Katrine Harder

    We propose the Logistic Non-negative Matrix Factorization for decomposition of binary data. Binary data are frequently generated in e.g. text analysis, sensory data, market basket data etc. A common method for analysing non-negative data is the Non-negative Matrix Factorization, though...... this is in theory not appropriate for binary data, and thus we propose a novel Non-negative Matrix Factorization based on the logistic link function. Furthermore we generalize the method to handle missing data. The formulation of the method is compared to a previously proposed method (Tome et al., 2015). We compare...... the performance of the Logistic Non-negative Matrix Factorization to Least Squares Non-negative Matrix Factorization and Kullback-Leibler (KL) Non-negative Matrix Factorization on sets of binary data: a synthetic dataset, a set of student comments on their professors collected in a binary term-document matrix...

  16. Local binary patterns new variants and applications

    CERN Document Server

    Jain, Lakhmi; Nanni, Loris; Lumini, Alessandra

    2014-01-01

    This book introduces Local Binary Patterns (LBP), arguably one of the most powerful texture descriptors, and LBP variants. This volume provides the latest reviews of the literature and a presentation of some of the best LBP variants by researchers at the forefront of textual analysis research and research on LBP descriptors and variants. The value of LBP variants is illustrated with reported experiments using many databases representing a diversity of computer vision applications in medicine, biometrics, and other areas. There is also a chapter that provides an excellent theoretical foundation for texture analysis and LBP in particular. A special section focuses on LBP and LBP variants in the area of face recognition, including thermal face recognition. This book will be of value to anyone already in the field as well as to those interested in learning more about this powerful family of texture descriptors.

  17. Some Bounds on Binary LCD Codes

    OpenAIRE

    Galvez, Lucky; Kim, Jon-Lark; Lee, Nari; Roe, Young Gun; Won, Byung-Sun

    2017-01-01

    A linear code with a complementary dual (or LCD code) is defined to be a linear code $C$ whose dual code $C^{\\perp}$ satisfies $C \\cap C^{\\perp}$= $\\left\\{ \\mathbf{0}\\right\\} $. Let $LCD{[}n,k{]}$ denote the maximum of possible values of $d$ among $[n,k,d]$ binary LCD codes. We give exact values of $LCD{[}n,k{]}$ for $1 \\le k \\le n \\le 12$. We also show that $LCD[n,n-i]=2$ for any $i\\geq2$ and $n\\geq2^{i}$. Furthermore, we show that $LCD[n,k]\\leq LCD[n,k-1]$ for $k$ odd and $LCD[n,k]\\leq LCD[...

  18. Dual jets from binary black holes.

    Science.gov (United States)

    Palenzuela, Carlos; Lehner, Luis; Liebling, Steven L

    2010-08-20

    The coalescence of supermassive black holes--a natural outcome when galaxies merge--should produce gravitational waves and would likely be associated with energetic electromagnetic events. We have studied the coalescence of such binary black holes within an external magnetic field produced by the expected circumbinary disk surrounding them. Solving the Einstein equations to describe black holes interacting with surrounding plasma, we present numerical evidence for possible jets driven by these systems. Extending the process described by Blandford and Znajek for a single, spinning black hole, the picture that emerges suggests that the electromagnetic field extracts energy from the orbiting black holes, which ultimately merge and settle into the standard Blandford-Znajek scenario. Emissions along these jets could potentially be observable at large distances.

  19. Predicting binary choices from probability phrase meanings.

    Science.gov (United States)

    Wallsten, Thomas S; Jang, Yoonhee

    2008-08-01

    The issues of how individuals decide which of two events is more likely and of how they understand probability phrases both involve judging relative likelihoods. In this study, we investigated whether derived scales representing probability phrase meanings could be used within a choice model to predict independently observed binary choices. If they can, this simultaneously provides support for our model and suggests that the phrase meanings are measured meaningfully. The model assumes that, when deciding which of two events is more likely, judges take a single sample from memory regarding each event and respond accordingly. The model predicts choice probabilities by using the scaled meanings of individually selected probability phrases as proxies for confidence distributions associated with sampling from memory. Predictions are sustained for 34 of 41 participants but, nevertheless, are biased slightly low. Sequential sampling models improve the fit. The results have both theoretical and applied implications.

  20. Learning from nature: binary cooperative complementary nanomaterials.

    Science.gov (United States)

    Su, Bin; Guo, Wei; Jiang, Lei

    2015-03-01

    In this Review, nature-inspired binary cooperative complementary nanomaterials (BCCNMs), consisting of two components with entirely opposite physiochemical properties at the nanoscale, are presented as a novel concept for the building of promising materials. Once the distance between the two nanoscopic components is comparable to the characteristic length of some physical interactions, the cooperation between these complementary building blocks becomes dominant and endows the macroscopic materials with novel and superior properties. The first implementation of the BCCNMs is the design of bio-inspired smart materials with superwettability and their reversible switching between different wetting states in response to various kinds of external stimuli. Coincidentally, recent studies on other types of functional nanomaterials contribute more examples to support the idea of BCCNMs, which suggests a potential yet comprehensive range of future applications in both materials science and engineering. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Energetic binary collisions in rare gas plasmas

    Science.gov (United States)

    Robinson, R. S.

    1979-01-01

    Calculations have been made of cross sections for energy and momentum transfer in binary collisions between like pairs of Ar, Kr, and Xe atoms in the energy range from about 1 to 1000 eV. These calculations were made using a classical model with pair interaction potentials for the rare gases developed from experimental sources, e.g., investigations of specific heats, viscosities, solid-state parameters, and scattering data. Cross sections in this energy range have not been available. The cross sections exhibit a rapid decrease from accepted values at thermal energies as the interaction energy increases. This behavior can be used to understand directed beam propagation limits as well as particle propagation within a plasma. Experimental data have also been fit to a theoretical expression for the Ar resonance charge exchange cross section over the same energy range.

  2. Renormalization of QED with planar binary trees

    International Nuclear Information System (INIS)

    Brouder, C.

    2001-01-01

    The Dyson relations between renormalized and bare photon and electron propagators Z 3 anti D(q)=D(q) and Z 2 anti S(q)=S(q) are expanded over planar binary trees. This yields explicit recursive relations for the terms of the expansions. When all the trees corresponding to a given power of the electron charge are summed, recursive relations are obtained for the finite coefficients of the renormalized photon and electron propagators. These relations significantly decrease the number of integrals to carry out, as compared to the standard Feynman diagram technique. In the case of massless quantum electrodynamics (QED), the relation between renormalized and bare coefficients of the perturbative expansion is given in terms of a Hopf algebra structure. (orig.)

  3. The binary collision approximation: Background and introduction

    International Nuclear Information System (INIS)

    Robinson, M.T.

    1992-08-01

    The binary collision approximation (BCA) has long been used in computer simulations of the interactions of energetic atoms with solid targets, as well as being the basis of most analytical theory in this area. While mainly a high-energy approximation, the BCA retains qualitative significance at low energies and, with proper formulation, gives useful quantitative information as well. Moreover, computer simulations based on the BCA can achieve good statistics in many situations where those based on full classical dynamical models require the most advanced computer hardware or are even impracticable. The foundations of the BCA in classical scattering are reviewed, including methods of evaluating the scattering integrals, interaction potentials, and electron excitation effects. The explicit evaluation of time at significant points on particle trajectories is discussed, as are scheduling algorithms for ordering the collisions in a developing cascade. An approximate treatment of nearly simultaneous collisions is outlined and the searching algorithms used in MARLOWE are presented

  4. Periastron advance in black-hole binaries.

    Science.gov (United States)

    Le Tiec, Alexandre; Mroué, Abdul H; Barack, Leor; Buonanno, Alessandra; Pfeiffer, Harald P; Sago, Norichika; Taracchini, Andrea

    2011-09-30

    The general relativistic (Mercury-type) periastron advance is calculated here for the first time with exquisite precision in full general relativity. We use accurate numerical relativity simulations of spinless black-hole binaries with mass ratios 1/8≤m(1)/m(2)≤1 and compare with the predictions of several analytic approximation schemes. We find the effective-one-body model to be remarkably accurate and, surprisingly, so also the predictions of self-force theory [replacing m(1)/m(2)→m(1)m(2)/(m(1)+m(2))(2)]. Our results can inform a universal analytic model of the two-body dynamics, crucial for ongoing and future gravitational-wave searches.

  5. Shock waves in binary oxides memristors

    Science.gov (United States)

    Tesler, Federico; Tang, Shao; Dobrosavljević, Vladimir; Rozenberg, Marcelo

    2017-09-01

    Progress of silicon based technology is nearing its physical limit, as minimum feature size of components is reaching a mere 5 nm. The resistive switching behavior of transition metal oxides and the associated memristor device is emerging as a competitive technology for next generation electronics. Significant progress has already been made in the past decade and devices are beginning to hit the market; however, it has been mainly the result of empirical trial and error. Hence, gaining theoretical insight is of essence. In the present work we report a new connection between the resistive switching and shock wave formation, a classic topic of non-linear dynamics. We argue that the profile of oxygen ions that migrate during the commutation in insulating binary oxides may form a shock wave, which propagates through a poorly conductive region of the device. We validate the scenario by means of model simulations.

  6. Solitary waves in dimer binary collision model

    Science.gov (United States)

    Ahsan, Zaid; Jayaprakash, K. R.

    2017-01-01

    Solitary wave propagation in nonlinear diatomic (dimer) chains is a very interesting topic of research in the study of nonlinear lattices. Such waves were recently found to be supported by the essentially nonlinear granular lattice and Toda lattice. An interesting aspect of this discovery is attributed to the realization of a spectrum of the mass ratio (the only system parameter governing the dynamics) that supports the propagation of such waves corresponding to the considered interaction potential. The objective of this exposition is to explore solitary wave propagation in the dimer binary collision (BC) model. Interestingly, the dimer BC model supports solitary wave propagation at a discrete spectrum of mass ratios similar to those observed in granular and Toda dimers. Further, we report a qualitative and one-to-one correspondence between the spectrum of the mass ratio corresponding to the dimer BC model and those corresponding to granular and Toda dimer chains.

  7. Wetting and evaporation of binary mixture drops.

    Science.gov (United States)

    Sefiane, Khellil; David, Samuel; Shanahan, Martin E R

    2008-09-11

    Experimental results on the wetting behavior of water, methanol, and binary mixture sessile drops on a smooth, polymer-coated substrate are reported. The wetting behavior of evaporating water/methanol drops was also studied in a water-saturated environment. Drop parameters (contact angle, shape, and volume) were monitored in time. The effects of the initial relative concentrations on subsequent evaporation and wetting dynamics were investigated. Physical mechanisms responsible for the various types of wetting behavior during different stages are proposed and discussed. Competition between evaporation and hydrodynamic flow are evoked. Using an environment saturated with water vapor allowed further exploration of the controlling mechanisms and underlying processes. Wetting stages attributed to differential evaporation of methanol were identified. Methanol, the more volatile component, evaporates predominantly in the initial stage. The data, however, suggest that a small proportion of methanol remained in the drop after the first stage of evaporation. This residual methanol within the drop seems to influence subsequent wetting behavior strongly.

  8. Using High-Mass X-ray Binaries to Probe Massive Binary Evolution

    Science.gov (United States)

    Garofali, Kristen; Williams, Ben

    2018-01-01

    High-mass X-ray binaries (HMXBs) provide an exciting window into the underlying processes of both binary as well as massive star evolution. Because HMXBs are systems containing a compact object accreting from a high-mass star at close orbital separations they are also likely progenitors of gamma-ray bursts and gravitational wave sources. I will present work on the classification and age measurements of HMXBs in M33 using a combination of deep Chandra X-ray imaging, and archival Hubble Space Telescope data. I am able to constrain the ages of the HMXB candidates by fitting the color-magnitude diagrams of the surrounding stars, which yield the star formation histories of the surrounding region. Unlike the age distributions measured for HMXB populations in the Magellenic Clouds, the age distribution for the HMXB population in M33 contains a number of extremely young (population.

  9. Formation of a contact binary star system

    International Nuclear Information System (INIS)

    Mullen, E.F.F.

    1974-01-01

    The process of forming a contact binary star system is investigated in the light of current knowledge of the W Ursae Majoris type eclipsing binaries and the current rotational braking theories for contracting stars. A preliminary stage of mass transfer is proposed and studied through the use of a computer program which calculates evolutionary model sequences. The detailed development of both stars is followed in these calculations, and findings regarding the internal structure of the star which is receiving the mass are presented. Relaxation of the mass-gaining star is also studied; for these stars of low mass and essentially zero age, the star eventually settles to a state very similar to a zero-age main sequence star of the new mass. A contact system was formed through these calculations; it exhibits the general properties of a W Ursae Majoris system. The initial masses selected for the calculation were 1.29 M/sub solar mass/ and 0.56 M/sub solar mass/. An initial mass transfer rate of about 10 -10 solar masses per year gradually increased to about 10 -8 solar masses per year. After about 2.5 x 10 7 years, the less massive star filled its Roche lobe and an initial contact system was obtained. The final masses were 1.01359 M/sub solar mass/ and 0.83641 M/sub solar mass/. The internal structure of the secondary component is considerably different from that of a main sequence star of the same mass

  10. Unification of binary star ephemeris solutions

    International Nuclear Information System (INIS)

    Wilson, R. E.; Van Hamme, W.

    2014-01-01

    Time-related binary system characteristics such as orbital period, its rate of change, apsidal motion, and variable light-time delay due to a third body, are measured in two ways that can be mutually complementary. The older way is via eclipse timings, while ephemerides by simultaneous whole light and velocity curve analysis have appeared recently. Each has its advantages, for example, eclipse timings typically cover relatively long time spans while whole curves often have densely packed data within specific intervals and allow access to systemic properties that carry additional timing information. Synthesis of the two information sources can be realized in a one step process that combines several data types, with automated weighting based on their standard deviations. Simultaneous light-velocity-timing solutions treat parameters of apsidal motion and the light-time effect coherently with those of period and period change, allow the phenomena to interact iteratively, and produce parameter standard errors based on the quantity and precision of the curves and timings. The logic and mathematics of the unification algorithm are given, including computation of theoretical conjunction times as needed for generation of eclipse timing residuals. Automated determination of eclipse type, recovery from inaccurate starting ephemerides, and automated data weighting are also covered. Computational examples are given for three timing-related cases—steady period change (XY Bootis), apsidal motion (V526 Sagittarii), and the light-time effect due to a binary's reflex motion in a triple system (AR Aurigae). Solutions for all combinations of radial velocity, light curve, and eclipse timing input show consistent results, with a few minor exceptions.

  11. Adsorption of Cr(VI) on cerium immobilized cross-linked chitosan composite in single system and coexisted with Orange II in binary system.

    Science.gov (United States)

    Zhu, Tianyi; Huang, Wei; Zhang, Lingfan; Gao, Jie; Zhang, Wenqing

    2017-10-01

    In this work, cerium immobilized cross-linked chitosan (CTS-Ce) composite, employed as an efficient adsorbent for Cr(VI) in single system and coexisted with Orange II (OII) in binary system, was prepared by co-precipitation method. The as-obtained adsorbent was characterized by FTIR, SEM, EDS and XPS before and after adsorption. The adsorption behaviors of Cr(VI) in single and binary system were systematically studied. The maximum adsorption capacity of Cr(VI) on CTS-Ce (202.8mg/g) was calculated by Langmuir equation in single metal system, but it decreased to 112.9mg/g with initial concentration of 100mg/L OII in binary system at pH 2 and 293K. The adsorption data for Cr(VI) followed the Langmuir model in single system, while fitted Temkin model well in binary system. In both single and binary system, the kinetics of adsorption exhibited pseudo-second order behavior and adsorption capacity increased with increasing temperature. Moreover, the data of thermodynamic parameters (ΔG°0) indicated that the adsorption was a spontaneous and endothermic process. Besides, |ΔG Cr |>|ΔG Cr-OII | at the same temperature further suggested that Cr(VI) was adsorbed on the CTS-Ce composite faster in binary system than in single system. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. New Light Curve Analysis for Large Numbers of Eclipsing Binaries I. Detached and Semi-Detached Binaries

    Directory of Open Access Journals (Sweden)

    Young-Woon Kang

    2010-06-01

    Full Text Available Several survey observations have produced light curves of more than five thousand eclipsing binaries for last 15 years. Future missions such as the Large Synoptic Survey Telescope (LSST, the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS and Gaia are expected to yield hundreds thousands of new variable stars and eclipsing binaries. Current methods require a week to analyze the light curves of an eclipsing binary for its physical and orbital parameters. The current methods of analyzing the light curves will be inadequate to treat the overwhelming influx of new data. Therefore we developed a new method to treat large numbers of light curves of eclipsing binaries. We tested the new method by analyzing more than one hundred light curves of the detached and semi-detached eclipsing binaries discovered in the Small Magellan Cloud and present their fitted light curves with observations.

  13. Runaway stars from young star clusters containing initial binaries. I. Equal-mass, equal-energy binaries

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, P.J.T.; Duncan, M.J.

    1988-07-01

    The production of runaway stars by the dynamical-ejection mechanism in an open star cluster containing 50 percent binaries of equal mass and energy is investigated theoretically by means of numerical simulations using the NBODY5 code of Aarseth (1985). The construction of the models is outlined, and the results are presented graphically and characterized in detail. It is shown that binary-binary collisions capable of producing runaways can occur (via formation and disruption, with some stellar collisions, of hierarchical double binaries) in clusters of relatively low density (e.g., pc-sized clusters of O or B stars). The frequency of binaries in the runaway population is found to vary between 0 and 50 percent, with the majority of runaways being unevolved early-type stars. 38 references.

  14. Formation and Evolution of X-ray Binaries

    Science.gov (United States)

    Shao, Y.

    2017-07-01

    X-ray binaries are a class of binary systems, in which the accretor is a compact star (i.e., black hole, neutron star, or white dwarf). They are one of the most important objects in the universe, which can be used to study not only binary evolution but also accretion disks and compact stars. Statistical investigations of these binaries help to understand the formation and evolution of galaxies, and sometimes provide useful constraints on the cosmological models. The goal of this thesis is to investigate the formation and evolution processes of X-ray binaries including Be/X-ray binaries, low-mass X-ray binaries (LMXBs), ultraluminous X-ray sources (ULXs), and cataclysmic variables. In Chapter 1 we give a brief review on the basic knowledge of the binary evolution. In Chapter 2 we discuss the formation of Be stars through binary interaction. In this chapter we investigate the formation of Be stars resulting from mass transfer in binaries in the Galaxy. Using binary evolution and population synthesis calculations, we find that in Be/neutron star binaries the Be stars have a lower limit of mass ˜ 8 M⊙ if they are formed by a stable (i.e., without the occurrence of common envelope evolution) and nonconservative mass transfer. We demonstrate that the isolated Be stars may originate from both mergers of two main-sequence stars and disrupted Be binaries during the supernova explosions of the primary stars, but mergers seem to play a much more important role. Finally the fraction of Be stars produced by binary interactions in all B type stars can be as high as ˜ 13%-30% , implying that most of Be stars may result from binary interaction. In Chapter 3 we show the evolution of intermediate- and low-mass X-ray binaries (I/LMXBs) and the formation of millisecond pulsars. Comparing the calculated results with the observations of binary radio pulsars, we report the following results: (1) The allowed parameter space for forming binary pulsars in the initial orbital period

  15. Eclipsing binary stars with a δ Scuti component

    Science.gov (United States)

    Kahraman Aliçavuş, F.; Soydugan, E.; Smalley, B.; Kubát, J.

    2017-09-01

    Eclipsing binaries with a δ Sct component are powerful tools to derive the fundamental parameters and probe the internal structure of stars. In this study, spectral analysis of six primary δ Sct components in eclipsing binaries has been performed. Values of Teff, v sin I, and metallicity for the stars have been derived from medium-resolution spectroscopy. Additionally, a revised list of δ Sct stars in eclipsing binaries is presented. In this list, we have only given the δ Sct stars in eclipsing binaries to show the effects of the secondary components and tidal-locking on the pulsations of primary δ Sct components. The stellar pulsation, atmospheric and fundamental parameters (e.g. mass, radius) of 92 δ Sct stars in eclipsing binaries have been gathered. Comparison of the properties of single and eclipsing binary member δ Sct stars has been made. We find that single δ Sct stars pulsate in longer periods and with higher amplitudes than the primary δ Sct components in eclipsing binaries. The v sin I of δ Sct components is found to be significantly lower than that of single δ Sct stars. Relationships between the pulsation periods, amplitudes and stellar parameters in our list have been examined. Significant correlations between the pulsation periods and the orbital periods, Teff, log g, radius, mass ratio, v sin I and the filling factor have been found.

  16. Minimum period and the gap in periods of Cataclysmic binaries

    International Nuclear Information System (INIS)

    Paczynski, B.; Sienkiewicz, R.

    1983-01-01

    The 81 minute cutoff to the orbital periods of hydrogen-rich cataclysmic binaries is consistent with evolution of those systems being dominated by angular momentum losses due to gravitational radiation. Unfortunately, many uncertainties, mainly poorly known atmospheric opacities below 2000 K, make is physically impossible to verify the quadrupole formula for gravitational radiation by using the observed cutoff at 81 minutes. The upper boundary of the gap in orbital periods observed at about 3 hours is almost certainly due to enhanced angular momentum losses from cataclysmic binaries which have longer periods. The physical mechanism of those losses is not identified, but a possible importance of stellar winds is pointed out. The lower boundary of the gap may be explained with the oldest cataclysmic binaries, whose periods evolved past the minimum at 81 minutes and reached the value of 2 hours within about 12 x 10 9 years after the binary had formed. Those binaries should have secondary components of only 0.02 solar masses, and their periods could be used to estimate ages of the oldest cataclysmic stars, and presumably the age of Galaxy. An alternative explanation for the gap requires that binaries should be detached while crossing the gap. A possible mechanism for this phenomenon is discussed. It requires the secondary components to be about 0.2 solar masses in the binaries just below the gap

  17. ``Supermassive Black-Hole Binaries in Merging Cusps''

    Science.gov (United States)

    Milosavljevic, M.; Merritt, D.

    2000-12-01

    We present N-body simulations of the formation and evolution of supermassive black-hole binaries in galactic nuclei. Initial conditions are drawn from a tree-code simulation of the merger of two spherical galaxies containing central point masses and ρ ~ r-2 central density cusps. Once the two black holes form a bound pair at the center of the merged galaxies, the evolution is continued using the Aarseth/Spurzem parallel tree code NBODY6++ at much higher resolution. Immediately following the formation of a hard black-hole binary, the density cusp of the merged galaxies is nearly homologous to the cusps in the initial galaxies. However the central density decreases rapidly as the binary black hole ejects stars which pass near to it, reducing the slope of the cusp from ~ r-2 to ~ r-1. When the distance between the black holes becomes comparable to the average stellar separation in the cusp, the binary begins to wander about the center while engaging in hard encounters with stars on radial orbits that are ejected at high speed. Ejection induces further shrinking of the binary at a decreasing rate. We discuss the dynamics of black hole binaries in the limit of large N, appropriate to real galactic nuclei, and discuss the possibility that supermassive black hole binaries can survive over cosmological times.

  18. Merger rate of primordial black-hole binaries

    Science.gov (United States)

    Ali-Haïmoud, Yacine; Kovetz, Ely D.; Kamionkowski, Marc

    2017-12-01

    Primordial black holes (PBHs) have long been a candidate for the elusive dark matter (DM), and remain poorly constrained in the ˜20 - 100 M⊙ mass range. PBH binaries were recently suggested as the possible source of LIGO's first detections. In this paper, we thoroughly revisit existing estimates of the merger rate of PBH binaries. We compute the probability distribution of orbital parameters for PBH binaries formed in the early Universe, accounting for tidal torquing by all other PBHs, as well as standard large-scale adiabatic perturbations. We then check whether the orbital parameters of PBH binaries formed in the early Universe can be significantly affected between formation and merger. Our analytic estimates indicate that the tidal field of halos and interactions with other PBHs, as well as dynamical friction by unbound standard DM particles, do not do significant work on nor torque PBH binaries. We estimate the torque due to baryon accretion to be much weaker than previous calculations, albeit possibly large enough to significantly affect the eccentricity of typical PBH binaries. We also revisit the PBH-binary merger rate resulting from gravitational capture in present-day halos, accounting for Poisson fluctuations. If binaries formed in the early Universe survive to the present time, as suggested by our analytic estimates, they dominate the total PBH merger rate. Moreover, this merger rate would be orders of magnitude larger than LIGO's current upper limits if PBHs make a significant fraction of the dark matter. As a consequence, LIGO would constrain ˜10 - 300 M⊙ PBHs to constitute no more than ˜1 % of the dark matter. To make this conclusion fully robust, though, numerical study of several complex astrophysical processes—such as the formation of the first PBH halos and how they may affect PBH binaries, as well as the accretion of gas onto an extremely eccentric binary—is needed.

  19. Manifold corrections on spinning compact binaries

    International Nuclear Information System (INIS)

    Zhong Shuangying; Wu Xin

    2010-01-01

    This paper deals mainly with a discussion of three new manifold correction methods and three existing ones, which can numerically preserve or correct all integrals in the conservative post-Newtonian Hamiltonian formulation of spinning compact binaries. Two of them are listed here. One is a new momentum-position scaling scheme for complete consistency of both the total energy and the magnitude of the total angular momentum, and the other is the Nacozy's approach with least-squares correction of the four integrals including the total energy and the total angular momentum vector. The post-Newtonian contributions, the spin effects, and the classification of orbits play an important role in the effectiveness of these six manifold corrections. They are all nearly equivalent to correct the integrals at the level of the machine epsilon for the pure Kepler problem. Once the third-order post-Newtonian contributions are added to the pure orbital part, three of these corrections have only minor effects on controlling the errors of these integrals. When the spin effects are also included, the effectiveness of the Nacozy's approach becomes further weakened, and even gets useless for the chaotic case. In all cases tested, the new momentum-position scaling scheme always shows the optimal performance. It requires a little but not much expensive additional computational cost when the spin effects exist and several time-saving techniques are used. As an interesting case, the efficiency of the correction to chaotic eccentric orbits is generally better than one to quasicircular regular orbits. Besides this, the corrected fast Lyapunov indicators and Lyapunov exponents of chaotic eccentric orbits are large as compared with the uncorrected counterparts. The amplification is a true expression of the original dynamical behavior. With the aid of both the manifold correction added to a certain low-order integration algorithm as a fast and high-precision device and the fast Lyapunov

  20. Massive Black Hole Binaries: Dynamical Evolution and Observational Signatures

    Directory of Open Access Journals (Sweden)

    M. Dotti

    2012-01-01

    Full Text Available The study of the dynamical evolution of massive black hole pairs in mergers is crucial in the context of a hierarchical galaxy formation scenario. The timescales for the formation and the coalescence of black hole binaries are still poorly constrained, resulting in large uncertainties in the expected rate of massive black hole binaries detectable in the electromagnetic and gravitational wave spectra. Here, we review the current theoretical understanding of the black hole pairing in galaxy mergers, with a particular attention to recent developments and open issues. We conclude with a review of the expected observational signatures of massive binaries and of the candidates discussed in literature to date.

  1. Strong binary pulsar constraints on Lorentz violation in gravity.

    Science.gov (United States)

    Yagi, Kent; Blas, Diego; Yunes, Nicolás; Barausse, Enrico

    2014-04-25

    Binary pulsars are excellent laboratories to test the building blocks of Einstein's theory of general relativity. One of these is Lorentz symmetry, which states that physical phenomena appear the same for all inertially moving observers. We study the effect of violations of Lorentz symmetry in the orbital evolution of binary pulsars and find that it induces a much more rapid decay of the binary's orbital period due to the emission of dipolar radiation. The absence of such behavior in recent observations allows us to place the most stringent constraints on Lorentz violation in gravity, thus verifying one of the cornerstones of Einstein's theory much more accurately than any previous gravitational observation.

  2. Creation of an anti-imaging system using binary optics

    Science.gov (United States)

    Wang, Haifeng; Lin, Jian; Zhang, Dawei; Wang, Yang; Gu, Min; Urbach, H. P.; Gan, Fuxi; Zhuang, Songlin

    2016-01-01

    We present a concealing method in which an anti-point spread function (APSF) is generated using binary optics, which produces a large-scale dark area in the focal region that can hide any object located within it. This result is achieved by generating two identical PSFs of opposite signs, one consisting of positive electromagnetic waves from the zero-phase region of the binary optical element and the other consisting of negative electromagnetic waves from the pi-phase region of the binary optical element. PMID:27620068

  3. Strong Binary Pulsar Constraints on Lorentz Violation in Gravity

    CERN Document Server

    Yagi, Kent; Yunes, Nicolas; Barausse, Enrico

    2014-01-01

    Binary pulsars are excellent laboratories to test the building blocks of Einstein's theory of General Relativity. One of these is Lorentz symmetry which states that physical phenomena appear the same for all inertially moving observers. We study the effect of violations of Lorentz symmetry in the orbital evolution of binary pulsars and find that it induces a much more rapid decay of the binary's orbital period due to the emission of dipolar radiation. The absence of such behavior in recent observations allows us to place the most stringent constraints on Lorentz violation in gravity, thus verifying one of the cornerstones of Einstein's theory much more accurately than any previous gravitational observation.

  4. Finding binaries from phase modulation of pulsating stars with Kepler

    Directory of Open Access Journals (Sweden)

    Shibahashi Hiromoto

    2017-01-01

    Full Text Available Binary orbital motion causes a periodic variation in the path length travelled by light emitted from a star towards us. Hence, if the star is pulsating, the observed phase of the pulsation varies over the orbit. Conversely, once we have observed such phase variation, we can extract information about the binary orbit from photometry alone. Continuous and precise space-based photometry has made it possible to measure these light travel time effects on the pulsating stars in binary systems. This opens up a new way of finding unseen brown dwarfs, planets, or massive compact stellar remnants: neutron stars and black holes.

  5. The BANANA Survey: Spin-Orbit Alignment in Binary Stars

    Science.gov (United States)

    Albrecht, Simon; Winn, J. N.; Fabrycky, D. C.; Torres, G.; Setiawan, J.

    2012-04-01

    Binaries are not always neatly aligned. Previous observations of the DI Herculis system showed that the spin axes of both stars are highly inclined with respect to one another and the orbital axis. Here, we report on our ongoing survey to measure relative orientations of spin-axes in a number of eclipsing binary systems. These observations will hopefully lead to new insights into star and planet formation, as different formation scenarios predict different degrees of alignment and different dependencies on the system parameters. Measurements of spin-orbit angles in close binary systems will also create a basis for comparison for similar measurements involving close-in planets.

  6. Estimation of the Ideal Binary Mask using Directional Systems

    DEFF Research Database (Denmark)

    Boldt, Jesper; Kjems, Ulrik; Pedersen, Michael Syskind

    2008-01-01

    The ideal binary mask is often seen as a goal for time-frequency masking algorithms trying to increase speech intelligibility, but the required availability of the unmixed signals makes it difficult to calculate the ideal binary mask in any real-life applications. In this paper we derive the theory...... and the requirements to enable calculations of the ideal binary mask using a directional system without the availability of the unmixed signals. The proposed method has a low complexity and is verified using computer simulation in both ideal and non-ideal setups showing promising results....

  7. THE BINARY FRACTION OF LOW-MASS WHITE DWARFS

    International Nuclear Information System (INIS)

    Brown, Justin M.; Kilic, Mukremin; Brown, Warren R.; Kenyon, Scott J.

    2011-01-01

    We describe spectroscopic observations of 21 low-mass (≤0.45 M sun ) white dwarfs (WDs) from the Palomar-Green survey obtained over four years. We use both radial velocities and infrared photometry to identify binary systems, and find that the fraction of single, low-mass WDs is ≤30%. We discuss the potential formation channels for these single stars including binary mergers of lower-mass objects. However, binary mergers are not likely to explain the observed number of single low-mass WDs. Thus, additional formation channels, such as enhanced mass loss due to winds or interactions with substellar companions, are likely.

  8. Interaction of Massive Black Hole Binaries with Their Stellar Environment. II. Loss Cone Depletion and Binary Orbital Decay

    Science.gov (United States)

    Sesana, Alberto; Haardt, Francesco; Madau, Piero

    2007-05-01

    We study the long-term evolution of massive black hole binaries (MBHBs) at the centers of galaxies using detailed scattering experiments to solve the full three-body problem. Ambient stars drawn from an isotropic Maxwellian distribution unbound to the binary are ejected by the gravitational slingshot. We construct a minimal, hybrid model for the depletion of the loss cone and the orbital decay of the binary and show that secondary slingshots-stars returning on small-impact parameter orbits to have a second superelastic scattering with the MBHB-may considerably help the shrinking of the pair in the case of large binary mass ratios. In the absence of loss cone refilling by two-body relaxation or other processes, the mass ejected before the stalling of a MBHB is half the binary reduced mass. About 50% of the ejected stars are expelled in a ``burst'' lasting ~104 yr M1/46, where M6 is the binary mass in units of 106 Msolar. The loss cone is completely emptied in a few bulge crossing timescales, ~107 yr M1/46. Even in the absence of two-body relaxation or gas dynamical processes, unequal mass and/or eccentric binaries with M6>~0.1 can shrink to the gravitational wave emission regime in less than a Hubble time and are therefore ``safe'' targets for the planned Laser Interferometer Space Antenna.

  9. Magneto Binary Nanofluid Convection in Porous Medium

    Directory of Open Access Journals (Sweden)

    Jyoti Sharma

    2016-01-01

    Full Text Available The effect of an externally impressed magnetic field on the stability of a binary nanofluid layer in porous medium is considered in this work. The conservation equations related to the system are solved using normal mode technique and Galerkin method to analyze the problem. The complex expressions are approximated to get useful results. Mode of heat transfer is stationary for top heavy distribution of nanoparticles in the fluid layer and top heavy nanofluids are very less stable than regular fluids. Oscillatory motions are possible for bottom heavy distribution of nanoparticles and they are not much influenced by properties of different nanoparticles. A comparative analysis of the instability of water based nanofluids with metallic (Cu, Ag and semiconducting (TiO2, SiO2 nanoparticles under the influence of magnetic field is examined. Semiconducting nanofluids are found to be more stable than metallic nanofluids. Porosity destabilizes the layer while solute difference (at the boundaries of the layer stabilizes it. Magnetic field stabilizes the fluid layer system significantly.

  10. A possible binary AGN in Mrk 622?

    Science.gov (United States)

    Benítez, E.; Rodríguez-Espinosa, J. M.; Cruz-González, I.; González-Martín, O.; Negrete, C. A.; Ruschel-Dutra, D.; Gutiérrez, L.; Jiménez-Bailón, E.

    2018-02-01

    Mrk 622 is a Compton thick active galactic nuclei (AGN) and a double-peaked narrow emission line galaxy, thus a dual AGN candidate. In this work, new optical long-slit spectroscopic observations clearly show that this object is rather a triple peaked narrow emission line galaxy, with both blue and red shifted narrow emission lines, as well as a much narrower emission line centred at the host galaxy systemic velocity. The average velocity offset between the blue and red shifted components is ˜500 km s-1, which is producing the apparent double-peaked emission lines. These two components are in the loci of AGN in the Baldwin, Phillips & Terlevich diagrams and are found to be spatially separated by ˜76 pc. Analysis of the optical spatially resolved spectroscopic observations presented in this work favours that Mrk 622 is a system consisting of a composite AGN amidst a binary AGN candidate, likely the result of a recent merger. This notwithstanding, outflows from a starburst, or single AGN could also explain the triple nature of the emission lines.

  11. A zoo of computable binary normal sequences.

    Science.gov (United States)

    Pincus, Steve; Singer, Burton H

    2012-11-20

    Historically there has been a virtual absence of constructive methods to produce broad classes of "certifiably random" infinite sequences, despite considerable interest in this endeavor. Previously, we proved a theorem that yielded explicit algorithms to produce diverse sets of normal numbers, reasonable candidates for random sequences, given their limiting equidistribution of subblocks of all lengths. Herein, we develop this algorithmic approach much further, systematizing the normal number generation process in several ways. We construct delineated, distinct sets of normal numbers (classified by the extent to which initial segments deviate from maximal irregularity), with virtually any allowable specified rate of convergence to 0 of this deviation, encompassing arbitrarily fast and slow rates, and accommodating asymmetric behavior above or below a centered median. As a corollary, we provide an explicit construction of a normal number that satisfies the Law of the Iterated Logarithm. We also produce distinct families of "biased" normal numbers, with virtually any specified rate of convergence of the bias (to 0). This latter theory is in part motivated by the remarkable observation that the binary version of Champernowne's number, which is also normal, is biased-any initial segment has more 1s than 0s. Finally, we construct an interesting normal sequence with arbitrarily fast convergence to equidistribution of singleton blocks, yet arbitrarily slow convergence of pairs, which has profound implications both for probability theory, and for metrics to evaluate the "near-randomness" of sequences.

  12. Neutral hydrogen observations of binary galaxies

    International Nuclear Information System (INIS)

    Moorsel, G.A. van.

    1982-01-01

    The present investigation concerns a detailed neutral hydrogen study of a carefully selected sample of 16 double spiral galaxies with the Westerbork Synthesis Radio Telescope (WSRT). The observational data provide useful material for a number of questions concerning the dynamics of double galaxies, in particular the question of the mass distribution. In Chapter 2 the criteria used to select a sample of double galaxies for observation with the WSRT are discussed. Observing techniques and the reduction of the data using the GIPSY system are described in Chapter 3. Chapters 4 through 7 contain the observational results. In Chapter 8 the method of analysis is described. Masses for the individual galaxies derived from rotation curves are compared with the ''total'' masses estimated from the orbital motion. In this fashion a direct estimate of the amount of dark matter is obtained that avoids the use of mean M/L values. In Chapter 9 a mass estimator for groups is developed in a way analogous to the binary galaxy mass estimator described in Chapter 8. The question of selection effects and the bias of the mass estimator for the point mass model are discussed extensively in Chapter 10. The final results are discussed in Chapter 11. It is shown that the orbital mass exceeds the sum of the individual masses by a large factor for several pairs, indicating either that there is a large amount of dark matter or that something is amiss with the concept of a physical pair. (Auth.)

  13. Preliminary design of a Binary Breeder Reactor

    International Nuclear Information System (INIS)

    Garcia C, E. Y.; Francois, J. L.; Lopez S, R. C.

    2014-10-01

    A binary breeder reactor (BBR) is a reactor that by means of the transmutation and fission process can operates through the depleted uranium burning with a small quantity of fissile material. The advantages of a BBR with relation to other nuclear reactor types are numerous, taking into account their capacity to operate for a long time without requiring fuel reload or re-arrangement. In this work four different simulations are shown carried out with the MCNPX code with libraries Jeff-3.1 to 1200 K. The objective of this study is to compare two different models of BBR: a spherical reactor and a cylindrical one, using two fuel cycles for each one of them (U-Pu and Th-U) and different reflectors for the two different geometries. For all the models a super-criticality state was obtained at least 10.9 years without carrying out some fuel re-arrangement or reload. The plutonium-239 production was achieved in the models where natural uranium was used in the breeding area, while the production of uranium-233 was observed in the cases where thorium was used in the fertile area. Finally, a behavior of stationary wave reactor was observed inside the models of spherical reactor when contemplating the power uniform increment in the breeding area, while inside the cylindrical models was observed the behavior of a traveling wave reactor when registering the displacement of the burnt wave along the cylindrical model. (Author)

  14. Overloaded CDMA Systems with Displaced Binary Signatures

    Directory of Open Access Journals (Sweden)

    Vanhaverbeke Frederik

    2004-01-01

    Full Text Available We extend three types of overloaded CDMA systems, by displacing in time the binary signature sequences of these systems: (1 random spreading (PN, (2 multiple-OCDMA (MO, and (3 PN/OCDMA (PN/O. For each of these systems, we determine the time shifts that minimize the overall multiuser interference power. The achievable channel load with coded and uncoded data is evaluated for the conventional (without displacement and improved (with displacement systems, as well as for systems based on quasi-Welch-bound-equality (QWBE sequences, by means of several types of turbo detectors. For each system, the best performing turbo detector is selected in order to compare the performance of these systems. It is found that the improved systems substantially outperform their original counterparts. With uncoded data, (improved PN/O yields the highest acceptable channel load. For coded data, MO allows for the highest acceptable channel load over all considered systems, both for the conventional and the improved systems. In the latter case, channel loads of about 280% are achievable with a low degradation as compared to a single user system.

  15. Hydrodynamic 'memory' of binary fluid mixtures

    International Nuclear Information System (INIS)

    Kalashnik, M. V.; Ingel, L. Kh.

    2006-01-01

    A theoretical analysis is presented of hydrostatic adjustment in a two-component fluid system, such as seawater stratified with respect to temperature and salinity. Both linear approximation and nonlinear problem are investigated. It is shown that scenarios of relaxation to a hydrostatically balanced state in binary fluid mixtures may substantially differ from hydrostatic adjustment in fluids that can be stratified only with respect to temperature. In particular, inviscid two-component fluids have 'memory': a horizontally nonuniform disturbance in the initial temperature or salinity distribution does not vanish even at the final stage, transforming into a persistent thermohaline 'trace.' Despite stability of density stratification and convective stability of the fluid system by all known criteria, an initial temperature disturbance may not decay and may even increase in amplitude. Moreover, its sign may change (depending on the relative contributions of temperature and salinity to stable background density stratification). Hydrostatic adjustment may involve development of discontinuous distributions from smooth initial temperature or concentration distributions. These properties of two-component fluids explain, in particular, the occurrence of persistent horizontally or vertically nonuniform temperature and salinity distributions in the ocean, including discontinuous ones

  16. Experimental investigation of stability and extinction coefficient of Al2O3–CuO binary nanoparticles dispersed in ethylene glycol–water mixture for low-temperature direct absorption solar collectors

    International Nuclear Information System (INIS)

    Menbari, Amir; Alemrajabi, Ali Akbar; Ghayeb, Yousef

    2016-01-01

    Highlights: • Viscosity and optical properties of binary nanofluids are investigated. • Effective parameters on stability of binary nanofluids are studied. • At optimal stability condition viscosity and absorbency of nanofluids are optimum. • The extinction coefficient of binary nanofluids is sum of its components ones. - Abstract: Binary nanofluids form a new class of nanofluids made through the simultaneous dispersion of two dissimilar nanoparticles in a base fluid. Two different nanoparticles may behave differently from their constituent components. Given the wide applications of binary nanofluids in a variety of fields, it is important to gain an understanding of the best stability conditions for binary nanofluids. In this work, the effects of such nanofluid properties as pH, surfactant (SHMP) concentration, and ultrasonic time are experimentally investigated on the stability of binary nanofluids. For this purpose, binary nanofluids are prepared using the two-step method. Two dissimilar nanoparticles, i.e. CuO and γ-Al 2 O 3 nanoparticles are dispersed in ethylene glycol and in the ethylene glycol–water mixture to form the desired nanofluids. Results show that at optimal stability conditions, viscosity and absorbency of the nanofluids are minimum and maximum, respectively. Also, the stability optimal parameters of binary nanofluids are found to be different from their corresponding values for each individual nanofluid. The extinction coefficient of the binary nanofluid is found to be approximately equal to the sum of those of the constituent components. Finally, the extinction coefficient of the nanoparticles dispersed in the mixture of ethylene glycol–water is determined to be greater than that of ethylene glycol.

  17. PREPARATION OF NICKEL - COBALT SPINEL OXIDES NixCO3 ...

    African Journals Online (AJOL)

    ABSTRACT. A comparative study of two electro-physical properties (porosity and electrical conductivity) of binary nickel cobalt oxides electrodes with spinels mixed oxides NixCo3-xO4 as active matter, was carried out. Four different routes were used to prepare spinel-type NixCo3-xO4 (0 ≤ x ≤. 2.5) compounds in order to ...

  18. Levetiracetam+nonsteroidal anti-inflammatory drug binary systems: A contribution to the development of new solid dosage forms.

    Science.gov (United States)

    Machado, Sara M T; Castro, Ricardo A E; Maria, Teresa M R; Canotilho, João; Eusébio, M Ermelinda S

    2017-11-25

    A study has been carried out of binary solid systems made up of the antiepileptic drug levetiracetam, LEV, and a nonsteroidal anti-inflammatory drug, NSAID, capable of managing the inflammation that accompanies epileptic activity. One aim of this research was to identify eutectic mixtures and co-crystals, which are able to impact positively on their biopharmaceutical properties. The NSAIDs studied are (S)- and (R,S)-ibuprofen, (S)- and (R,S)-naproxen, (R,S)-ketoprofen and (R,S)-flurbiprofen, all class II in the Biopharmaceutical Classification System. A green mechanochemical methodology has been used to prepare binary mixtures with different molar ratios, and the binary solid-liquid phase diagrams established. For LEV+(S)-ibuprofen, formation of a single (1:1) co-crystal was confirmed; this was found to melt incongruently. The co-crystal was found to be stable in accelerated stability tests. For the other systems, interesting eutectic mixtures were identified, which showed enhanced dissolution rates of the NSAID relative to the pure drug. For LEV+(R,S)-ibuprofen, LEV+(S)-naproxen and LEV+(R,S)-naproxen, the eutectic mixture compositions have the effective doses of both components. All the NSAIDs investigated are chiral, and their racemates are racemic compounds. Levetiracetam, the (S)-enantiomer of etiracetam, was not efficient in enantiomer discrimination, as all the racemic compound structures are present as the prepared solid mixtures. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Structure of binary mixed polymer Langmuir layers

    NARCIS (Netherlands)

    Bernardini, C.

    2012-01-01

    The possibility of preparing 2D stable emulsions through mixing of homopolymers in a Langmuir monolayer is the core topic of this thesis. While colloid science has achieved well established results in the study of bulk dispersed systems, accounts on properties of mixed monomolecular films are fewer,

  20. Structure of binary mixed polymer Langmuir layers

    NARCIS (Netherlands)

    Bernardini, C.

    2012-01-01

    The possibility of preparing 2D stable emulsions through mixing of homopolymers in a Langmuir monolayer is the core topic of this thesis. While colloid science has achieved well established results in the study of bulk dispersed systems, accounts on properties of mixed monomolecular films are

  1. Speech Segregation based on Binary Classification

    Science.gov (United States)

    2016-07-15

    copyright information. 13. SUPPLEMENTARY NOTES. Enter information not included elsewhere such as: prepared in cooperation with; translation of...Audience is a provider of audio and noise suppression processors for mobile equipment, including Android phones. The PI advises the company on speech

  2. Population of Nuclei Via 7Li-Induced Binary Reactions

    Energy Technology Data Exchange (ETDEWEB)

    Clark, Rodney M.; Phair, Larry W.; Descovich, M.; Cromaz, Mario; Deleplanque, M.A.; Fall on, Paul; Lee, I-Yang; Macchiavelli, A.O.; McMahan, Margaret A.; Moretto, Luciano G.; Rodriguez-Vieitez, E.; Sinha,Shrabani; Stephens, Frank S.; Ward, David; Wiedeking, Mathis

    2005-08-08

    The authors have investigated the population of nuclei formed in binary reactions involving {sup 7}Li beams on targets of {sup 160}Gd and {sup 184}W. The {sup 7}Li + {sup 184}W data were taken in the first experiment using the LIBERACE Ge-array in combination with the STARS Si {Delta}E-E telescope system at the 88-Inch Cyclotron of the Lawrence Berkeley National Laboratory. By using the Wilczynski binary transfer model, in combination with a standard evaporation model, they are able to reproduce the experimental results. This is a useful method for predicting the population of neutron-rich heavy nuclei formed in binary reactions involving beams of weakly bound nuclei formed in binary reactions involving beams of weakly bound nuclei and will be of use in future spectroscopic studies.

  3. Analyzing Influenza Virus Sequences using Binary Encoding Approach

    Directory of Open Access Journals (Sweden)

    Ham Ching Lam

    2012-01-01

    Full Text Available Capturing mutation patterns of each individual influenza virus sequence is often challenging; in this paper, we demonstrated that using a binary encoding scheme coupled with dimension reduction technique, we were able to capture the intrinsic mutation pattern of the virus. Our approach looks at the variance between sequences instead of the commonly used p-distance or Hamming distance. We first convert the influenza genetic sequences to a binary strings and form a binary sequence alignment matrix and then apply Principal Component Analysis (PCA to this matrix. PCA also provides identification power to identify reassortant virus by using data projection technique. Due to the sparsity of the binary string, we were able to analyze large volume of influenza sequence data in a very short time. For protein sequences, our scheme also allows the incorporation of biophysical properties of each amino acid. Here, we present various encouraging results from analyzing influenza nucleotide, protein and genome sequences using the proposed approach.

  4. Rotation invariant deep binary hashing for fast image retrieval

    Science.gov (United States)

    Dai, Lai; Liu, Jianming; Jiang, Aiwen

    2017-07-01

    In this paper, we study how to compactly represent image's characteristics for fast image retrieval. We propose supervised rotation invariant compact discriminative binary descriptors through combining convolutional neural network with hashing. In the proposed network, binary codes are learned by employing a hidden layer for representing latent concepts that dominate on class labels. A loss function is proposed to minimize the difference between binary descriptors that describe reference image and the rotated one. Compared with some other supervised methods, the proposed network doesn't have to require pair-wised inputs for binary code learning. Experimental results show that our method is effective and achieves state-of-the-art results on the CIFAR-10 and MNIST datasets.

  5. Contamination of RR Lyrae stars from Binary Evolution Pulsators

    Science.gov (United States)

    Karczmarek, Paulina; Pietrzyński, Grzegorz; Belczyński, Krzysztof; Stępień, Kazimierz; Wiktorowicz, Grzegorz; Iłkiewicz, Krystian

    2016-06-01

    Binary Evolution Pulsator (BEP) is an extremely low-mass member of a binary system, which pulsates as a result of a former mass transfer to its companion. BEP mimics RR Lyrae-type pulsations but has different internal structure and evolution history. We present possible evolution channels to produce BEPs, and evaluate the contamination value, i.e. how many objects classified as RR Lyrae stars can be undetected BEPs. In this analysis we use population synthesis code StarTrack.

  6. KIC 7177553: A QUADRUPLE SYSTEM OF TWO CLOSE BINARIES

    Energy Technology Data Exchange (ETDEWEB)

    Lehmann, H. [Thüringer Landessternwarte Tautenburg, Sternwarte 5, D-07778 Tautenburg (Germany); Borkovits, T. [Baja Astronomical Observatory of Szeged University, H-6500 Baja, Szegedi út, Kt. 766 (Hungary); Rappaport, S. A. [Massachusetts Institute of Technology, Department of Physics, 77 Massachusetts Avenue, Cambridge, MA 02139-4307 (United States); Ngo, H. [California Institute of Technology, Division of Geological and Planetary Sciences, 1200 E. California Boulevard, MC 150-21, Pasadena, CA 91125 (United States); Mawet, D. [California Institute of Technology, Astronomy Dept. MC 249-17, 1200 E. California Boulevard, Pasadena, CA 91125 (United States); Csizmadia, Sz. [German Aerospace Center (DLR), Institut für Planeten-forschung, Rutherfordstraße 2, D-12489 Berlin (Germany); Forgács-Dajka, E., E-mail: lehm@tls-tautenburg.de, E-mail: borko@electra.bajaobs.hu, E-mail: sar@mit.edu, E-mail: hngo@caltech.edu, E-mail: dmawet@astro.caltech.edu, E-mail: szilard.csizmadia@dlr.de, E-mail: e.forgacs-dajka@astro.elte.hu [Astronomical Department, Eötvös University, H-1118 Budapest, Pázmány Péter stny. 1/A (Hungary)

    2016-03-01

    KIC 7177553 was observed by the Kepler satellite to be an eclipsing eccentric binary star system with an 18-day orbital period. Recently, an eclipse timing study of the Kepler binaries has revealed eclipse timing variations (ETVs) in this object with an amplitude of ∼100 s and an outer period of 529 days. The implied mass of the third body is that of a super-Jupiter, but below the mass of a brown dwarf. We therefore embarked on a radial velocity (RV) study of this binary to determine its system configuration and to check the hypothesis that it hosts a giant planet. From the RV measurements, it became immediately obvious that the same Kepler target contains another eccentric binary, this one with a 16.5-day orbital period. Direct imaging using adaptive optics reveals that the two binaries are separated by 0.″4 (∼167 AU) and have nearly the same magnitude (to within 2%). The close angular proximity of the two binaries and very similar γ velocities strongly suggest that KIC 7177553 is one of the rare SB4 systems consisting of two eccentric binaries where at least one system is eclipsing. Both systems consist of slowly rotating, nonevolved, solar-like stars of comparable masses. From the orbital separation and the small difference in γ velocity, we infer that the period of the outer orbit most likely lies in the range of 1000–3000 yr. New images taken over the next few years, as well as the high-precision astrometry of the Gaia satellite mission, will allow us to set much narrower constraints on the system geometry. Finally, we note that the observed ETVs in the Kepler data cannot be produced by the second binary. Further spectroscopic observations on a longer timescale will be required to prove the existence of the massive planet.

  7. Flare Activity of Wide Binary Stars with Kepler

    Science.gov (United States)

    Clarke, Riley W.; Davenport, James R. A.; Covey, Kevin R.; Baranec, Christoph

    2018-01-01

    We present an analysis of flare activity in wide binary stars using a combination of value-added data sets from the NASA Kepler mission. The target list contains a set of previously discovered wide binary star systems identified by proper motions in the Kepler field. We cross-matched these systems with estimates of flare activity for ∼200,000 stars in the Kepler field, allowing us to compare relative flare luminosity between stars in coeval binaries. From a sample of 184 previously known wide binaries in the Kepler field, we find 58 with detectable flare activity in at least 1 component, 33 of which are similar in mass (q > 0.8). Of these 33 equal-mass binaries, the majority display similar (±1 dex) flare luminosity between both stars, as expected for stars of equal mass and age. However, we find two equal-mass pairs where the secondary (lower mass) star is more active than its counterpart, and two equal-mass pairs where the primary star is more active. The stellar rotation periods are also anomalously fast for stars with elevated flare activity. Pairs with discrepant rotation and activity qualitatively seem to have lower mass ratios. These outliers may be due to tidal spin-up, indicating these wide binaries could be hierarchical triple systems. We additionally present high-resolution adaptive optics images for two wide binary systems to test this hypothesis. The demographics of stellar rotation and magnetic activity between stars in wide binaries may be useful indicators for discerning the formation scenarios of these systems.

  8. Thermodynamic analysis of the Ga-Pb binary system

    Directory of Open Access Journals (Sweden)

    Manasijević Dragan

    2003-01-01

    Full Text Available Thermodynamic properties of binary Ga-Pb alloys were investigated experimentally and analytically. Quantitative differential thermal analysis was used for determination of integral mixing enthalpies for the gallium-reach alloys, at the constant temperature inside the liquid two-phase region. Calculation of gallium activities in the temperature range of 800-1000 K was done using Chou’s calculation model developed for binary systems with miscibility gap existence.

  9. Recognition algorithms for binary signed-graphic matroids

    OpenAIRE

    Pitsoulis, Leonidas; Papalamprou, Konstantinos

    2010-01-01

    In this paper we provide two recognition algorithms for the class of signed-graphic matroids along with necessary and sufficient conditions for a matroid to be signed-graphic. Specifically, we provide a polynomial-time algorithm which determines whether a given binary matroid is signed-graphic and an algorithm which determines whether a general matroid given by an independece oracle is binary signed-graphic.

  10. Milankovitch cycles of terrestrial planets in binary star systems

    Science.gov (United States)

    Forgan, Duncan

    2016-12-01

    The habitability of planets in binary star systems depends not only on the radiation environment created by the two stars, but also on the perturbations to planetary orbits and rotation produced by the gravitational field of the binary and neighbouring planets. Habitable planets in binaries may therefore experience significant perturbations in orbit and spin. The direct effects of orbital resonances and secular evolution on the climate of binary planets remain largely unconsidered. We present latitudinal energy balance modelling of exoplanet climates with direct coupling to an N-Body integrator and an obliquity evolution model. This allows us to simultaneously investigate the thermal and dynamical evolution of planets orbiting binary stars, and discover gravito-climatic oscillations on dynamical and secular time-scales. We investigate the Kepler-47 and Alpha Centauri systems as archetypes of P- and S-type binary systems, respectively. In the first case, Earth-like planets would experience rapid Milankovitch cycles (of order 1000 yr) in eccentricity, obliquity and precession, inducing temperature oscillations of similar periods (modulated by other planets in the system). These secular temperature variations have amplitudes similar to those induced on the much shorter time-scale of the binary period. In the Alpha Centauri system, the influence of the secondary produces eccentricity variations on 15 000 yr time-scales. This produces climate oscillations of similar strength to the variation on the orbital time-scale of the binary. Phase drifts between eccentricity and obliquity oscillations creates further cycles that are of order 100 000 yr in duration, which are further modulated by neighbouring planets.

  11. Pattern 1^j0^i avoiding binary words

    Directory of Open Access Journals (Sweden)

    Stefano Bilotta

    2011-08-01

    Full Text Available In this paper we study the enumeration and the construction, according to the number of ones, of particular binary words avoiding a fixed pattern. The growth of such words can be described by particular jumping and marked succession rules. This approach enables us to obtain an algorithm which constructs all binary words having a fixed number of ones and then kills those containing the forbidden pattern.

  12. Hyperspectral image representation and processing with binary partition trees

    OpenAIRE

    Valero Valbuena, Silvia

    2012-01-01

    Premi extraordinari doctorat curs 2011-2012, àmbit Enginyeria de les TIC The optimal exploitation of the information provided by hyperspectral images requires the development of advanced image processing tools. Therefore, under the title Hyperspectral image representation and Processing with Binary Partition Trees, this PhD thesis proposes the construction and the processing of a new region-based hierarchical hyperspectral image representation: the Binary Partition Tree (BPT). This hierarc...

  13. Exergy Losses in the Szewalski Binary Vapor Cycle

    OpenAIRE

    Kowalczyk, Tomasz; Ziółkowski, Paweł; Badur, Janusz

    2015-01-01

    In this publication, we present an energy and exergy analysis of the Szewalski binary vapor cycle based on a model of a supercritical steam power plant. We used energy analysis to conduct a preliminary optimization of the cycle. Exergy loss analysis was employed to perform a comparison of heat-transfer processes, which are essential for hierarchical cycles. The Szewalski binary vapor cycle consists of a steam cycle bottomed with an organic Rankine cycle installation. This coupling has a negat...

  14. The Impact of Gaia and LSST on Binaries and Exoplanets

    DEFF Research Database (Denmark)

    Eyer, L.; Dubath, P.; Mowlavi, N.

    2012-01-01

    Two upcoming large scale surveys, the ESA Gaia and LSST projects, will bring a new era in astronomy. The number of binary systems that will be observed and detected by these projects is enormous, estimations range from millions for Gaia to several tens of millions for LSST. We review some tools t...... that should be developed and also what can be gained from these missions on the subject of binaries and exoplanets from the astrometry, photometry, radial velocity and their alert systems....

  15. The Binary Customer Satisfaction Model in Inventory and Queueing Systems

    OpenAIRE

    Azadivar, Justin Sepehr

    2010-01-01

    This dissertation introduces the Binary Customer Satisfaction Model for addressing logistics issues. In typical logistics problems, the arrival of customers through a demand process is considered external to the management decisions. In practice, it is typically the case that customers will respond to changes is service policy by changing their behavior. The Binary Customer Satisfaction Model provides a simple customer behavior model that directly interacts with the service policy and provide...

  16. Efficient Convolutional Neural Network with Binary Quantization Layer

    OpenAIRE

    Ravanbakhsh, Mahdyar; Mousavi, Hossein; Nabi, Moin; Marcenaro, Lucio; Regazzoni, Carlo

    2016-01-01

    In this paper we introduce a novel method for segmentation that can benefit from general semantics of Convolutional Neural Network (CNN). Our segmentation proposes visually and semantically coherent image segments. We use binary encoding of CNN features to overcome the difficulty of the clustering on the high-dimensional CNN feature space. These binary encoding can be embedded into the CNN as an extra layer at the end of the network. This results in real-time segmentation. To the best of our ...

  17. Binary black holes on a budget: simulations using workstations

    International Nuclear Information System (INIS)

    Marronetti, Pedro; Tichy, Wolfgang; Bruegmann, Bernd; Gonzalez, Jose; Hannam, Mark; Husa, Sascha; Sperhake, Ulrich

    2007-01-01

    Binary black hole simulations have traditionally been computationally very expensive: current simulations are performed in supercomputers involving dozens if not hundreds of processors, thus systematic studies of the parameter space of binary black hole encounters still seem prohibitive with current technology. Here we show how the multi-layered refinement level code BAM can be used on dual processor workstations to simulate certain binary black hole systems. BAM, based on the moving punctures method, provides grid structures composed of boxes of increasing resolution near the centre of the grid. In the case of binaries, the highest resolution boxes are placed around each black hole and they track them in their orbits until the final merger when a single set of levels surrounds the black hole remnant. This is particularly useful when simulating spinning black holes since the gravitational fields gradients are larger. We present simulations of binaries with equal mass black holes with spins parallel to the binary axis and intrinsic magnitude of S/m 2 = 0.75. Our results compare favourably to those of previous simulations of this particular system. We show that the moving punctures method produces stable simulations at maximum spatial resolutions up to M/160 and for durations of up to the equivalent of 20 orbital periods

  18. A New Orbit for the Eclipsing Binary V577 Oph

    Science.gov (United States)

    Jeffery, Elizabeth J.; Barnes, Thomas G., III; Skillen, Ian; Montemayor, Thomas J.

    2017-09-01

    Pulsating stars in eclipsing binary systems are unique objects for providing constraints on stellar models. To fully leverage the information available from the binary system, full orbital radial velocity curves must be obtained. We report 23 radial velocities for components of the eclipsing binary V577 Oph, whose primary star is a δ Sct variable. The velocities cover a nearly complete orbit and a time base of 20 years. We computed orbital elements for the binary and compared them to the ephemeris computed by Creevey et al. The comparison shows marginally different results. In particular, a change in the systemic velocity by -2 km s-1 is suggested by our results. We compare this systemic velocity difference to that expected due to reflex motion of the binary in response to the third body in the system. The systemic velocity difference is consistent with reflex motion, given our mass determination for the eclipsing binary and the orbital parameters determined by Volkov & Volkova for the three-body orbit. We see no evidence for the third body in our spectra, but we do see strong interstellar Na D lines that are consistent in strength with the direction and expected distance of V577 Oph.

  19. Binary Cockroach Swarm Optimization for Combinatorial Optimization Problem

    Directory of Open Access Journals (Sweden)

    Ibidun Christiana Obagbuwa

    2016-09-01

    Full Text Available The Cockroach Swarm Optimization (CSO algorithm is inspired by cockroach social behavior. It is a simple and efficient meta-heuristic algorithm and has been applied to solve global optimization problems successfully. The original CSO algorithm and its variants operate mainly in continuous search space and cannot solve binary-coded optimization problems directly. Many optimization problems have their decision variables in binary. Binary Cockroach Swarm Optimization (BCSO is proposed in this paper to tackle such problems and was evaluated on the popular Traveling Salesman Problem (TSP, which is considered to be an NP-hard Combinatorial Optimization Problem (COP. A transfer function was employed to map a continuous search space CSO to binary search space. The performance of the proposed algorithm was tested firstly on benchmark functions through simulation studies and compared with the performance of existing binary particle swarm optimization and continuous space versions of CSO. The proposed BCSO was adapted to TSP and applied to a set of benchmark instances of symmetric TSP from the TSP library. The results of the proposed Binary Cockroach Swarm Optimization (BCSO algorithm on TSP were compared to other meta-heuristic algorithms.

  20. The Detection and Parameter Estimation of Binary Black Hole Mergers

    Science.gov (United States)

    Biwer, Christopher M.

    In this dissertation we study gravitational-wave data analysis techniques for binary neutron star and black hole mergers. During its first observing run, the Advanced Laser Interferometer Gravitational-wave Observatory (Advanced LIGO) reported the first, direct observations of gravitational waves from two binary black hole mergers. We present the results from the search for binary black hole mergers which unambiguously detected the binary black hole mergers. We determine the effect of calibration errors on the detection statistic of the search. Since the search is not designed to precisely measure the astrophysical parameters of the binary neutron star and black hole mergers, we use Bayesian methods to develop a new parameter estimation analysis. We demonstrate the performance of the analysis on the binary black hole mergers detected during Advanced LIGO's first observing run. We use the parameter estimation analysis to assess the ability of gravitational-wave observatories to observe a gap in the black hole mass distribution between 52 M and 133 M due to pair-instability supernovae. Finally, we use simulated signals added to the Advanced LIGO detectors to validate the search and parameter estimation analyses used to publish the detection of the astrophysical events.

  1. Dynamical evolution of a fictitious population of binary Neptune Trojans

    Science.gov (United States)

    Brunini, Adrián

    2018-03-01

    We present numerical simulations of the evolution of a synthetic population of Binary Neptune Trojans, under the influence of the solar perturbations and tidal friction (the so-called Kozai cycles and tidal friction evolution). Our model includes the dynamical influence of the four giant planets on the heliocentric orbit of the binary centre of mass. In this paper, we explore the evolution of initially tight binaries around the Neptune L4 Lagrange point. We found that the variation of the heliocentric orbital elements due to the libration around the Lagrange point introduces significant changes in the orbital evolution of the binaries. Collisional processes would not play a significant role in the dynamical evolution of Neptune Trojans. After 4.5 × 109 yr of evolution, ˜50 per cent of the synthetic systems end up separated as single objects, most of them with slow diurnal rotation rate. The final orbital distribution of the surviving binary systems is statistically similar to the one found for Kuiper Belt Binaries when collisional evolution is not included in the model. Systems composed by a primary and a small satellite are more fragile than the ones composed by components of similar sizes.

  2. Learning Short Binary Codes for Large-scale Image Retrieval.

    Science.gov (United States)

    Liu, Li; Yu, Mengyang; Shao, Ling

    2017-03-01

    Large-scale visual information retrieval has become an active research area in this big data era. Recently, hashing/binary coding algorithms prove to be effective for scalable retrieval applications. Most existing hashing methods require relatively long binary codes (i.e., over hundreds of bits, sometimes even thousands of bits) to achieve reasonable retrieval accuracies. However, for some realistic and unique applications, such as on wearable or mobile devices, only short binary codes can be used for efficient image retrieval due to the limitation of computational resources or bandwidth on these devices. In this paper, we propose a novel unsupervised hashing approach called min-cost ranking (MCR) specifically for learning powerful short binary codes (i.e., usually the code length shorter than 100 b) for scalable image retrieval tasks. By exploring the discriminative ability of each dimension of data, MCR can generate one bit binary code for each dimension and simultaneously rank the discriminative separability of each bit according to the proposed cost function. Only top-ranked bits with minimum cost-values are then selected and grouped together to compose the final salient binary codes. Extensive experimental results on large-scale retrieval demonstrate that MCR can achieve comparative performance as the state-of-the-art hashing algorithms but with significantly shorter codes, leading to much faster large-scale retrieval.

  3. A New Orbit for the Eclipsing Binary V577 Oph

    Energy Technology Data Exchange (ETDEWEB)

    Jeffery, Elizabeth J. [Physics Department, California Polytechnic State University, San Luis Obispo, CA 93407 (United States); Barnes, Thomas G. III; Montemayor, Thomas J. [The University of Texas at Austin, McDonald Observatory, 1 University Station, C1402, Austin, TX 78712-0259 (United States); Skillen, Ian, E-mail: ejjeffer@calpoly.edu, E-mail: tgb@astro.as.utexas.edu, E-mail: tm@astro.as.utexas.edu, E-mail: wji@ing.iac.es [Isaac Newton Group, Apartado de Correos 321, E-38700 Santa Cruz de La Palma, Canary Islands (Spain)

    2017-09-01

    Pulsating stars in eclipsing binary systems are unique objects for providing constraints on stellar models. To fully leverage the information available from the binary system, full orbital radial velocity curves must be obtained. We report 23 radial velocities for components of the eclipsing binary V577 Oph, whose primary star is a δ Sct variable. The velocities cover a nearly complete orbit and a time base of 20 years. We computed orbital elements for the binary and compared them to the ephemeris computed by Creevey et al. The comparison shows marginally different results. In particular, a change in the systemic velocity by −2 km s{sup −1} is suggested by our results. We compare this systemic velocity difference to that expected due to reflex motion of the binary in response to the third body in the system. The systemic velocity difference is consistent with reflex motion, given our mass determination for the eclipsing binary and the orbital parameters determined by Volkov and Volkova for the three-body orbit. We see no evidence for the third body in our spectra, but we do see strong interstellar Na D lines that are consistent in strength with the direction and expected distance of V577 Oph.

  4. Preparing for Surgery

    Science.gov (United States)

    ... FAQs Preparing for Surgery Page Navigation ▼ ACOG Pregnancy Book Preparing for Surgery Patient Education FAQs Preparing for ... the person who is in charge of giving anesthesia and checking its effects. What can I do ...

  5. Application of wavelet and Fuorier transforms as powerful alternatives for derivative spectrophotometry in analysis of binary mixtures: A comparative study

    Science.gov (United States)

    Hassan, Said A.; Abdel-Gawad, Sherif A.

    2018-02-01

    Two signal processing methods, namely, Continuous Wavelet Transform (CWT) and the second was Discrete Fourier Transform (DFT) were introduced as alternatives to the classical Derivative Spectrophotometry (DS) in analysis of binary mixtures. To show the advantages of these methods, a comparative study was performed on a binary mixture of Naltrexone (NTX) and Bupropion (BUP). The methods were compared by analyzing laboratory prepared mixtures of the two drugs. By comparing performance of the three methods, it was proved that CWT and DFT methods are more efficient and advantageous in analysis of mixtures with overlapped spectra than DS. The three signal processing methods were adopted for the quantification of NTX and BUP in pure and tablet forms. The adopted methods were validated according to the ICH guideline where accuracy, precision and specificity were found to be within appropriate limits.

  6. Complex Macrophase-Separated Nanostructure Induced by Microphase Separation in Binary Blends of Lamellar Diblock Copolymer Thin Films

    DEFF Research Database (Denmark)

    Zhang, Jianqi; Posselt, Dorthe; Smilgies, Detlef-M.

    2014-01-01

    in a one-phase state, indicating that the higher molar mass diblock copolymer dominates the lamellar orientation. The lamellar thickness decreases linearly with increasing volume fraction of the low molar mass diblock copolymer. After SVA, well-defined macrophase-separated nanostructures appear, which......The nanostructures of thin films spin-coated from binary blends of compositionally symmetric polystyrene-b-polybutadiene (PS-b-PB) diblock copolymer having different molar masses are investigated by means of atomic force microscopy (AFM) and grazing-incidence small-angle X-ray scattering (GISAXS......) after spin-coating and after subsequent solvent vapor annealing (SVA). In thin films of the pure diblock copolymers having high or low molar mass, the lamellae are perpendicular or parallel to the substrate, respectively. The as-prepared binary blend thin films feature mainly perpendicular lamellae...

  7. Gene selection using hybrid binary black hole algorithm and modified binary particle swarm optimization.

    Science.gov (United States)

    Pashaei, Elnaz; Pashaei, Elham; Aydin, Nizamettin

    2018-04-14

    In cancer classification, gene selection is an important data preprocessing technique, but it is a difficult task due to the large search space. Accordingly, the objective of this study is to develop a hybrid meta-heuristic Binary Black Hole Algorithm (BBHA) and Binary Particle Swarm Optimization (BPSO) (4-2) model that emphasizes gene selection. In this model, the BBHA is embedded in the BPSO (4-2) algorithm to make the BPSO (4-2) more effective and to facilitate the exploration and exploitation of the BPSO (4-2) algorithm to further improve the performance. This model has been associated with Random Forest Recursive Feature Elimination (RF-RFE) pre-filtering technique. The classifiers which are evaluated in the proposed framework are Sparse Partial Least Squares Discriminant Analysis (SPLSDA); k-nearest neighbor and Naive Bayes. The performance of the proposed method was evaluated on two benchmark and three clinical microarrays. The experimental results and statistical analysis confirm the better performance of the BPSO (4-2)-BBHA compared with the BBHA, the BPSO (4-2) and several state-of-the-art methods in terms of avoiding local minima, convergence rate, accuracy and number of selected genes. The results also show that the BPSO (4-2)-BBHA model can successfully identify known biologically and statistically significant genes from the clinical datasets. Copyright © 2018 Elsevier Inc. All rights reserved.

  8. Outbursts In Symbiotic Binaries (FUSE 2000)

    Science.gov (United States)

    Kenyon, Scott J.; Sonneborn, George (Technical Monitor)

    2002-01-01

    During the past year, we made good progress on analysis of FUSE observations of the symbiotic binary Z And. For background, Z And is a binary system composed of a red giant and a hot component of unknown status. The orbital period is roughly 750 days. The hot component undergoes large-scale eruptions every 10-20 yr. An outburst began several years ago, triggering this FUSE opportunity. First, we obtained an excellent set of ground-based optical data in support, of the FUSE observations. We used FAST, a high throughput low resolution spectrograph on the 1.5-m telescope at Mt. Hopkins, Arizona. A 300 g/ mm grating blazed at 4750 A, a 3 in. slit, and a thinned Loral 512 x 2688 CCD gave us spectra covering 3800-7500 A at a resolution of 6 A. The wavelength solution for each spectrum has a probable error of +/- 0.5 A or better. Most of the resulting spectra have moderate signal-to-noise, S/.N approx. greater than 30 per pixel. The time coverage for these spectra is excellent. Typically, we acquired spectra every 1-2 nights during dark runs at Mt. Hopkins. These data cover most of the rise and all of the decline of the recent outburst. The spectra show a wealth of emission lines, including H I, He I, He II, [Fe V11], and the Raman scattering bands at 6830 A and 7088 A. The Raman bands and other high ionization features vary considerably throughout the outburst. These features will enable us to correlate variations in the FUSE spectra with variations in the optical spectra. Second, we began an analysis of FUSE spectra of Z And. We have carefully examined the spectra, identifying real features and defects. We have identified and measured fluxes for all strong emission lines, including the O VI doublet at 1032 A and 1038 A. These and several other strong emission lines display pronounced P Cygni absorption components indicative of outgrowing gas. We will attempt to correlate these velocities with similar profiles observed on optical spectra. The line velocities - together

  9. A spectroscopic study of southern binary Cepheids

    Science.gov (United States)

    Petterson, O. K. L.; Albrow, Michael D.; Cottrell, P. L.; Fokin, A.

    2004-05-01

    High-resolution spectroscopic observations have been made of a number of southern binary Cepheids to determine their dynamical masses. The stars are part of a long-term program to observe southern variable starsf or which a valuable long-term database has been obtained. The most recent radial velocities have a precision of ~300 ms-1, allowing the detection of velocity differences of ~1 kms-1 with confidence. Masses were determined for three systems: the 9-day Cepheid S Mus (6.0±0.4 MSolar), the double-mode Cepheid Y Car (4.5±1.8 MSolar) and the 5-day Cepheid V350 Sgr (6.0±0.9 MSolar). For five Cepheids (YZ Car, AX Cir, V636 Sco, W Sgr and T Mon) new or improved orbital solutions were found. Line level effects have been observed in several species of lines. Most Cepheids were observed to show the same progression of line level effects. Using non-linear radiative hydrodynamical models, we have compared the results of these models with our observations. These have shown that AX Cir and YZ Car have the following properties: L = 2050 LSolar, M = 4.8 MSolar, Teff = 5900 K and L = 9350 LSolar, M = 7.7 MSolar, Teff = 5590 K. Our models show no strong shockwaves being produced. Good agreement was found between the observed and modelled spectral lines Fe I 5576Å, SiII 6347Å, BaII 5853Å and CaII 8542Å.

  10. Binary analysis: 1. part: definitions and treatment of binary functions; 2. part: applications and functions of trans-coding

    International Nuclear Information System (INIS)

    Vallee, R.L.

    1968-01-01

    The study of binary groups under their mathematical aspects constitutes the matter of binary analysis, the purpose of which consists in developing altogether simple, rigorous and practical methods needed by the technicians, the engineers and all those who may be mainly concerned by digital processing. This subject, fast extending if not determining, however tends actually to play a main part in nuclear electronics as well as in several other research areas. (authors) [fr

  11. Structure of binary mixed polymer Langmuir layers

    OpenAIRE

    Bernardini, C.

    2012-01-01

    The possibility of preparing 2D stable emulsions through mixing of homopolymers in a Langmuir monolayer is the core topic of this thesis. While colloid science has achieved well established results in the study of bulk dispersed systems, accounts on properties of mixed monomolecular films are fewer, and seldom systematic. The aim of this investigation is to contribute to a deeper understanding of the subject, in order to explore opportunities to apply the acquired knowledge to the fabrication...

  12. The Brave New World of Binary Star Studies

    Science.gov (United States)

    Guinan, Edward F.; Engle, Scott G.

    2006-08-01

    In this paper we discuss some of the new and exciting developments in the study of binary stars. Recent technological advances (such as CCDs) now make it possible (even easy) to study faint, astrophysically important binaries that in the past could only be done with large 4 + meter class telescopes. Also, the panoramic nature of CCDs (and the use of mosaics), permit large numbers of stars to be imaged and studied. At this conference, most of the observational material discussed was secured typically with smaller aperture 0.5 - 2 m telescopes. Excellent examples are the discovery of over 104 new ˜13 - 20 mag eclipsing (and interacting) binaries now found in nearby galaxies from the EROS, OGLE, MACHO and DIRECT programs. As briefly discussed here, and in more detail in several papers in this volume, a small fraction of these extragalactic eclipsing binaries are now serving as “standard candles” to secure accurate distances to the Magellanic Clouds, as well as to M31 and M33. Moreover, the discovery of increasingly larger numbers of eclipsing binaries has stimulated the development of automatic methods for reducing and analyzing the light curves of thousands of systems. In the near future, hundreds of thousands (possibly millions) of additional systems are expected to be discovered by Pan-STARRS, the Large Synoptic Survey Telescopes (LSST), and later by GAIA. Over the last decade, new classes of binary systems have also been found which contain Jupiter-size planets and binaries containing pulsating stars. Some examples of these important binaries are discussed. Also discussed are the increasing numbers (now eight) of eclipsing binary planet-star systems that have been found from high precision photometry. These systems are very important since the radii and masses of the hosted planets can be directly measured. Moreover, from the upcoming COROT and KEPLER missions hundreds of additional transiting planet-star systems are expected to be found. All in all, we hope

  13. Pulsed Accretion in the T Tauri Binary TWA 3A

    Energy Technology Data Exchange (ETDEWEB)

    Tofflemire, Benjamin M.; Mathieu, Robert D. [Department of Astronomy, University of Wisconsin–Madison, 475 North Charter Street, Madison, WI 53706 (United States); Herczeg, Gregory J. [The Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China); Akeson, Rachel L.; Ciardi, David R. [NASA Exoplanet Science Institute, IPAC/Caltech, Pasadena, CA 91125 (United States)

    2017-06-20

    TWA 3A is the most recent addition to a small group of young binary systems that both actively accrete from a circumbinary disk and have spectroscopic orbital solutions. As such, it provides a unique opportunity to test binary accretion theory in a well-constrained setting. To examine TWA 3A’s time-variable accretion behavior, we have conducted a two-year, optical photometric monitoring campaign, obtaining dense orbital phase coverage (∼20 observations per orbit) for ∼15 orbital periods. From U -band measurements we derive the time-dependent binary mass accretion rate, finding bursts of accretion near each periastron passage. On average, these enhanced accretion events evolve over orbital phases 0.85 to 1.05, reaching their peak at periastron. The specific accretion rate increases above the quiescent value by a factor of ∼4 on average but the peak can be as high as an order of magnitude in a given orbit. The phase dependence and amplitude of TWA 3A accretion is in good agreement with numerical simulations of binary accretion with similar orbital parameters. In these simulations, periastron accretion bursts are fueled by periodic streams of material from the circumbinary disk that are driven by the binary orbit. We find that TWA 3A’s average accretion behavior is remarkably similar to DQ Tau, another T Tauri binary with similar orbital parameters, but with significantly less variability from orbit to orbit. This is only the second clear case of orbital-phase-dependent accretion in a T Tauri binary.

  14. Eclipsing Binaries From the CSTAR Project at Dome A, Antarctica

    Science.gov (United States)

    Yang, Ming; Zhang, Hui; Wang, Songhu; Zhou, Ji-Lin; Zhou, Xu; Wang, Lingzhi; Wang, Lifan; Wittenmyer, R. A.; Liu, Hui-Gen; Meng, Zeyang; Ashley, M. C. B.; Storey, J. W. V.; Bayliss, D.; Tinney, Chris; Wang, Ying; Wu, Donghong; Liang, Ensi; Yu, Zhouyi; Fan, Zhou; Feng, Long-Long; Gong, Xuefei; Lawrence, J. S.; Liu, Qiang; Luong-Van, D. M.; Ma, Jun; Wu, Zhenyu; Yan, Jun; Yang, Huigen; Yang, Ji; Yuan, Xiangyan; Zhang, Tianmeng; Zhu, Zhenxi; Zou, Hu

    2015-04-01

    The Chinese Small Telescope ARray (CSTAR) has observed an area around the Celestial South Pole at Dome A since 2008. About 20,000 light curves in the i band were obtained during the observation season lasting from 2008 March to July. The photometric precision achieves about 4 mmag at i = 7.5 and 20 mmag at i = 12 within a 30 s exposure time. These light curves are analyzed using Lomb-Scargle, Phase Dispersion Minimization, and Box Least Squares methods to search for periodic signals. False positives may appear as a variable signature caused by contaminating stars and the observation mode of CSTAR. Therefore, the period and position of each variable candidate are checked to eliminate false positives. Eclipsing binaries are removed by visual inspection, frequency spectrum analysis, and a locally linear embedding technique. We identify 53 eclipsing binaries in the field of view of CSTAR, containing 24 detached binaries, 8 semi-detached binaries, 18 contact binaries, and 3 ellipsoidal variables. To derive the parameters of these binaries, we use the Eclipsing Binaries via Artificial Intelligence method. The primary and secondary eclipse timing variations (ETVs) for semi-detached and contact systems are analyzed. Correlated primary and secondary ETVs confirmed by false alarm tests may indicate an unseen perturbing companion. Through ETV analysis, we identify two triple systems (CSTAR J084612.64-883342.9 and CSTAR J220502.55-895206.7). The orbital parameters of the third body in CSTAR J220502.55-895206.7 are derived using a simple dynamical model.

  15. Binary mixtures of waxy wheat and conventional wheat as measured by NIR reflectance.

    Science.gov (United States)

    Delwiche, Stephen R; Graybosch, Robert A

    2016-01-01

    Waxy wheat contains very low concentration (generally industries seek to have a rapid technique to ensure the purity of identity preserved waxy wheat lots. Near infrared (NIR) reflectance spectroscopy, a technique widely used in the cereals industry for proximate analysis, is a logical candidate for measuring contamination level and thus is the subject of this study. Two sets of wheat samples, harvested, prepared and scanned one year apart, were used to evaluate the NIR concept. One year consisted of nine pairs of conventional:waxy preparations, with each preparation consisting of 29 binary mixtures ranging in conventional wheat fraction (by weight) of 0-100% (261 spectral samples). The second year was prepared in the same fashion, with 12 preparations, thus producing 348 spectral samples. One year's samples were controlled for protein content and moisture level between pair components in order to avoid the basis for the conventional wheat fraction models being caused by something other than spectral differences attributed to waxy and nonwaxy endosperm. Likewise the second year was controlled by selection of conventional wheat for mixture preparation based on either protein content or cluster analysis of principal components of candidate spectra. Partial least squares regression, one and two-term linear regression, and support vector machine regression models were examined. Validation statistics arising from sets within the same year or across years were remarkably similar, as were those among the three regression types. A single wavelength on second derivative transformed spectra, namely 2290 nm, was effective at estimating the mixture level by weight, with standard errors of performance in the 6-9% range. Thus, NIR spectroscopy may be used for measuring conventional hard wheat 'contamination' in waxy wheat at mixture levels above 10% w/w. Published by Elsevier B.V.

  16. Optimization of binary breeder reactor VI - An acceptable project of binary breeder reactor

    International Nuclear Information System (INIS)

    Ishiguro, Y.; Dias, A.F.

    1986-05-01

    A binary breeder reactor that achieves desired characteristics reasonably well has been developed. Its design and characteristics are reported. Previous models showed several complications that result from introduction of 233 U/Th fuel in the core of a LMFBR, compared to purely Pu/U fueled ones. In this new model, the core is made larger to achieve higher breeding ratios and longer refueling intervals, the number of fuel assemblies is increased to accomodate a larger number of control rod assemblies required to compensate for reactivity losses and to control oscillations of the power densities, and, consequently, the fuel inventories are higher. High fuel burnups are achieved without too much complications in the refueling schedule and the power densities can be maintained reasonably constant over an operational cycle. Low sodium void reactivity reduce the potential for severe accidents and a reasonably efficient utilization of thorium can be realized. (Author) [pt

  17. The binary eutectic of NSAIDS and two-phase liquid system for enhanced membrane permeation.

    Science.gov (United States)

    Yuan, Xudong; Capomacchia, A C

    2005-01-01

    The eutectic properties of binary mixtures of some nonsteroidal anti-inflammatory drugs (NSAIDs) with ibuprofen were studied using differential scanning calorimetry (DSC) and phase equilibrium diagrams. The melting points of selected NSAIDs were significantly depressed due to binary eutectic formation with ibuprofen. Ketoprofen and ibuprofen were selected to study the effect of eutectic formation on membrane permeation using Franz diffusion cells and snake skin as the model membrane. The presence of aqueous isopropyl alcohol (IPA) was necessary to completely transform the solid drugs into an oily state at ambient temperature. As much as the 99.6% of ibuprofen and the 88.8% of ketoprofen added were found in the oily phase of the two-phase liquid system formed when aqueous IPA was added to the eutectic mixture. Due to the high drug concentration in the oily phase, and maximum thermodynamic activity, the two-phase liquid system showed enhanced membrane permeation rates of ibuprofen (37.5 microg/cm2/hr) and ketoprofen (33.4 microg/cm2/hr) compared to other reference preparations used.

  18. Novel two wavelength spectrophotometric methods for simultaneous determination of binary mixtures with severely overlapping spectra

    Science.gov (United States)

    Lotfy, Hayam M.; Saleh, Sarah S.; Hassan, Nagiba Y.; Salem, Hesham

    2015-02-01

    This work presents the application of different spectrophotometric techniques based on two wavelengths for the determination of severely overlapped spectral components in a binary mixture without prior separation. Four novel spectrophotometric methods were developed namely: induced dual wavelength method (IDW), dual wavelength resolution technique (DWRT), advanced amplitude modulation method (AAM) and induced amplitude modulation method (IAM). The results of the novel methods were compared to that of three well-established methods which were: dual wavelength method (DW), Vierordt's method (VD) and bivariate method (BV). The developed methods were applied for the analysis of the binary mixture of hydrocortisone acetate (HCA) and fusidic acid (FSA) formulated as topical cream accompanied by the determination of methyl paraben and propyl paraben present as preservatives. The specificity of the novel methods was investigated by analyzing laboratory prepared mixtures and the combined dosage form. The methods were validated as per ICH guidelines where accuracy, repeatability, inter-day precision and robustness were found to be within the acceptable limits. The results obtained from the proposed methods were statistically compared with official ones where no significant difference was observed. No difference was observed between the obtained results when compared to the reported HPLC method, which proved that the developed methods could be alternative to HPLC techniques in quality control laboratories.

  19. Generation of Polymer Nanocomposites through Shear-Driven Aggregation of Binary Colloids

    Directory of Open Access Journals (Sweden)

    Xinxin Sheng

    2017-11-01

    Full Text Available Design of polymer nanocomposites has been an intense research topic in recent decades because hybrid nanomaterials are widely used in many fields. Throughout their development, there has often been a challenging issue how one can uniformly distribute nanoparticles (NPs in a polymer matrix, avoiding their agglomeration. In this short review, we first introduce the theory of colloidal aggregation/gelation purely based on intense shear forces. Then, we illustrate a methodology for preparing polymer nanocomposites where the NPs (as fillers are uniformly and randomly distributed inside a matrix of polymer NPs, based on intense shear-driven aggregation of binary colloids, without using any additives. Its feasibility has been demonstrated using two stable binary colloids composed of (1 poly-methyl methacrylate fillers and polystyrene NPs, and (2 graphene oxide sheets (fillers and poly-vinylidene fluoride NPs. The mechanism leading to capturing and distribution of the fillers inside the polymer NP matrix has been illustrated, and the advantages of the proposed methodology compared with the other common methods are also discussed.

  20. Bandwidth enhancement in microwave absorption of binary nanocomposite ferrites hollow microfibers.

    Science.gov (United States)

    Song, Fuzhan; Shen, Xiangqian; Yang, Xinchun; Meng, Xianfeng; Xiang, Jun; Liu, Ruijiang; Dong, Mingdong

    2013-04-01

    The binary Ba0.5Sr0.5Fe12O19 (BSFO)/Ni0.5Zn0.5Fe2O4 (NZFO) nanocomposite ferrites hollow microfibers with high aspect ratios have been prepared by the gel precursor transformation process. These microfibers possess a high specific surface area about 45.2 m2 g(-1), and a ratio of the hollow diameter to the fiber diameter estimated about 5/7. The binary nanocomposite ferrites are formed after the precursor calcined at 750 degrees C for 3 h. Their minimum reflection loss (RL) is -38.1 dB at 10.4 GHz. The microwave absorption bandwidth with RL value exceeding -20 dB covers the whole X-band (8.2-12.4 GHz) and Ku-band (12.4-18 GHz). This enhancement in microwave absorption can be attributed to the exchange-coupling interaction, interfacial polarization and small size effect in nanocomposite hollow microfibers.

  1. Enthalpy relaxation studies of two structurally related amorphous drugs and their binary dispersions.

    Science.gov (United States)

    Bansal, Shyam Sunder; Kaushal, Aditya Mohan; Bansal, Arvind Kumar

    2010-11-01

    The purpose of the current study was to evaluate the enthalpy relaxation behavior of valdecoxib (VLB) and etoricoxib (ETB) and their binary dispersions to derive relaxation constants and to understand their molecular mobilities. Solid dispersions of VLB and ETB were prepared with 1%, 2%, 5%, 10%, 15%, and 20% (w/w) concentrations of polyvinylpyrrolidone (PVP) in situ using differential scanning calorimetry (DSC). Enthalpy relaxation studies were carried out with isothermal storage periods of 1, 2, 4, 6, 16, and 24 hours at 40°C and 0% relative humidity (RH). PVP increased the glass transition temperature (T(g)) and decreased the enthalpy relaxation. Significant differences between two drugs were observed with respect to their relaxation behavior which may be due to differences in intermolecular interactions as predicted by Couchman-Karasz equation and molecular mobility. Kohlrausch-Williams-Watts equation was found to be inadequate in describing complex molecular relaxations in binary dispersions. The enthalpy relaxation behavior of VLB and ETB was found to be significantly different. PVP stabilized VLB significantly; however, its effect on ETB was negligible. The extent of enthalpy relaxation was found to correlate with hydrogen bonding tendency of the drug molecules. The outcome can help in rational designing of amorphous systems with optimal performance.

  2. Electrodeposition and Thermoelectric Properties of Cu-Se Binary Compound Films

    Science.gov (United States)

    Yang, Mengqian; Shen, Zhengwu; Liu, Xiaoqing; Wang, Wei

    2016-03-01

    Cu-Se binary compound films have been prepared by electrodeposition from solutions containing CuSO4, H2SeO3, and H2SO4 and their composition, structure, and thermoelectric performance analyzed. Moving the depositing potential negatively increased the Cu content in the film, remarkably so for relatively low Cu2+ concentration in the solution. X-ray diffraction analysis showed that the phase composition of the films varied with their Cu content. Cu-Se binary compound films electrodeposited from solutions with different concentration ratios of CuSO4 to H2SeO3 showed two different phases: α-Cu2- x Se (monoclinic) with Se content in the range of 33.3 at.% to 33.8 at.%, and β-Cu2Se (cubic) with Se content in the range of 35.3 at.% to 36.0 at.%. The highest power factor for electrodeposited Cu2- x Se film was 0.13 mW/(K2 m) with Seebeck coefficient of 56.0 μV/K.

  3. Synthesis of gelatin nano/submicron particles by binary nonsolvent aided coacervation (BNAC) method.

    Science.gov (United States)

    Patra, Shamayita; Basak, Piyali; Tibarewala, D N

    2016-02-01

    A newly developed modified coacervation method is utilized to synthesize gelatin nano/submicron particles (GN/SPs) as a drug carrier. Binary nonsolvent aided coacervation (BNAC) method is a modified single step coacervation method, which has yielded approximately a threefold lower particle size and higher average yield in terms of weight percentage of around 94% in comparison to the conventional phase separation methods. In this study 0.5% (w/v) gelatin aqueous solution with a binary nonsolvent system of acetone and ethanol was used. Nanoparticle synthesis was optimized with respect to nonsolvent system type and pH. pH7 has resulted a minimum particle size of 55.67 (±43.74) nm in anhydrous medium along with a swollen particle size of 776nm (±38.57) in aqueous medium with a zeta potential of (-16.3±3.51) mV in aqueous medium. Swelling ratio of 13.95 confirms the crosslinked hydrogel nature of the particles. Furthermore, drug loading efficiency of the gelatin particles prepared at 7pH was observed with nitrofurazone as the model drug. Results of drug release study indicate the potential use of GN/SPs as drug loading matrix for wound management such as burn wound management. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Testing the Binary Hypothesis: Pulsar Timing Constraints on Supermassive Black Hole Binary Candidates

    Science.gov (United States)

    Sesana, Alberto; Haiman, Zoltán; Kocsis, Bence; Kelley, Luke Zoltan

    2018-03-01

    The advent of time domain astronomy is revolutionizing our understanding of the universe. Programs such as the Catalina Real-time Transient Survey (CRTS) or the Palomar Transient Factory (PTF) surveyed millions of objects for several years, allowing variability studies on large statistical samples. The inspection of ≈250 k quasars in CRTS resulted in a catalog of 111 potentially periodic sources, put forward as supermassive black hole binary (SMBHB) candidates. A similar investigation on PTF data yielded 33 candidates from a sample of ≈35 k quasars. Working under the SMBHB hypothesis, we compute the implied SMBHB merger rate and we use it to construct the expected gravitational wave background (GWB) at nano-Hz frequencies, probed by pulsar timing arrays (PTAs). After correcting for incompleteness and assuming virial mass estimates, we find that the GWB implied by the CRTS sample exceeds the current most stringent PTA upper limits by almost an order of magnitude. After further correcting for the implicit bias in virial mass measurements, the implied GWB drops significantly but is still in tension with the most stringent PTA upper limits. Similar results hold for the PTF sample. Bayesian model selection shows that the null hypothesis (whereby the candidates are false positives) is preferred over the binary hypothesis at about 2.3σ and 3.6σ for the CRTS and PTF samples respectively. Although not decisive, our analysis highlights the potential of PTAs as astrophysical probes of individual SMBHB candidates and indicates that the CRTS and PTF samples are likely contaminated by several false positives.

  5. UNUSUALLY WIDE BINARIES: ARE THEY WIDE OR UNUSUAL?

    International Nuclear Information System (INIS)

    Kraus, Adam L.; Hillenbrand, Lynne A.

    2009-01-01

    We describe an astrometric and spectroscopic campaign to confirm the youth and association of a complete sample of candidate wide companions in Taurus and Upper Sco. Our survey found 15 new binary systems (three in Taurus and 12 in Upper Sco) with separations of 3''-30'' (500-5000 AU) among all of the known members with masses of 2.5-0.012 M sun . The total sample of 49 wide systems in these two regions conforms to only some expectations from field multiplicity surveys. Higher mass stars have a higher frequency of wide binary companions, and there is a marked paucity of wide binary systems near the substellar regime. However, the separation distribution appears to be log-flat, rather than declining as in the field, and the mass ratio distribution is more biased toward similar-mass companions than the initial mass function or the field G-dwarf distribution. The maximum separation also shows no evidence of a limit at ∼ sun . We attribute this result to the post-natal dynamical sculpting that occurs for most field systems; our binary systems will escape to the field intact, but most field stars are formed in denser clusters and undergo significant dynamical evolution. In summary, only wide binary systems with total masses ∼ sun appear to be 'unusually wide'.

  6. Formation of Thorne-Żytkow objects in close binaries

    Science.gov (United States)

    Hutilukejiang, Bumareyamu; Zhu, Chunhua; Wang, Zhaojun; Lü, Guoliang

    2018-04-01

    Thorne-Żytkow objects (TŻOs), originally proposed by Thorne and Żytkow, may form as a result of unstable mass transfer in a massive X-ray binary after a neutron star (NS) is engulfed in the envelope of its companion star. Using a rapid binary evolution program and the Monte Carlo method, we simulated the formation of TŻOs in close binary stars. The Galactic birth rate of TŻOs is about 1.5× 10^{-4} yr^{-1}. Their progenitors may be composed of a NS and a main-sequence star, a star in the Hertzsprung gap or a core-helium burning, or a naked helium star. The birth rates of TŻOs via the above different progenitors are 1.7× 10^{-5}, 1.2× 10^{-4}, 0.7× 10^{-5}, 0.6× 10^{-5} yr^{-1}, respectively. These progenitors may be massive X-ray binaries. We found that the observational properties of three massive X-ray binaries (SMC X-1, Cen X-3 and LMC X-4) in which the companions of NSs may fill their Roche robes were consistent with those of their progenitors.

  7. Rotational properties of hypermassive neutron stars from binary mergers

    Science.gov (United States)

    Hanauske, Matthias; Takami, Kentaro; Bovard, Luke; Rezzolla, Luciano; Font, José A.; Galeazzi, Filippo; Stöcker, Horst

    2017-08-01

    Determining the differential-rotation law of compact stellar objects produced in binary neutron stars mergers or core-collapse supernovae is an old problem in relativistic astrophysics. Addressing this problem is important because it impacts directly on the maximum mass these objects can attain and, hence, on the threshold to black-hole formation under realistic conditions. Using the results from a large number of numerical simulations in full general relativity of binary neutron star mergers described with various equations of state and masses, we study the rotational properties of the resulting hypermassive neutron stars. We find that the angular-velocity distribution shows only a modest dependence on the equation of state, thus exhibiting the traits of "quasiuniversality" found in other aspects of compact stars, both isolated and in binary systems. The distributions are characterized by an almost uniformly rotating core and a "disk." Such a configuration is significantly different from the j -constant differential-rotation law that is commonly adopted in equilibrium models of differentially rotating stars. Furthermore, the rest-mass contained in such a disk can be quite large, ranging from ≃0.03 M⊙ in the case of high-mass binaries with stiff equations of state, up to ≃0.2 M⊙ for low-mass binaries with soft equations of state. We comment on the astrophysical implications of our findings and on the long-term evolutionary scenarios that can be conjectured on the basis of our simulations.

  8. A DEEPLY ECLIPSING DETACHED DOUBLE HELIUM WHITE DWARF BINARY

    International Nuclear Information System (INIS)

    Parsons, S. G.; Marsh, T. R.; Gaensicke, B. T.; Drake, A. J.; Koester, D.

    2011-01-01

    Using Liverpool Telescope+RISE photometry we identify the 2.78 hr period binary star CSS 41177 as a detached eclipsing double white dwarf binary with a 21,100 K primary star and a 10,500 K secondary star. This makes CSS 41177 only the second known eclipsing double white dwarf binary after NLTT 11748. The 2 minute long primary eclipse is 40% deep and the secondary eclipse 10% deep. From Gemini+GMOS spectroscopy, we measure the radial velocities of both components of the binary from the Hα absorption line cores. These measurements, combined with the light curve information, yield white dwarf masses of M 1 = 0.283 ± 0.064 M sun and M 2 = 0.274 ± 0.034 M sun , making them both helium core white dwarfs. As an eclipsing, double-lined spectroscopic binary, CSS 41177 is ideally suited to measuring precise, model-independent masses and radii. The two white dwarfs will merge in roughly 1.1 Gyr to form a single sdB star.

  9. Busting Up Binaries: Stellar Interactions With Galactic Supermassive Black Holes

    Science.gov (United States)

    Addison, Eric; Larson, S.; Laguna, P.

    2012-05-01

    Gravitational wave astronomy is a new observational tool that will enhance our understanding of the Cosmos. Virtually everything we know about the Cosmos has been learned through observations of light; gravitational waves are a fundamentally different spectrum that can be used to learn about distant astrophysical systems. Einstein's theory of General Relativity predicts the existence of gravitational waves, and it is well known that stellar-mass compact object (CO) binaries will be among the most abundant and easily detectable sources. Extreme mass ratio inspirals are expected to provide an interesting potential source for gravitational wave detectors, however these systems are generally studied in the context of a single star orbiting a black hole. In this work, the case of a CO binary on a parabolic trajectory around a super massive black hole (SMBH) is considered. Numerical simulations are used to explore perturbations to the orbital parameters of the binary after interaction with the SMBH, including de-circularization and possible tidal capture. Additionally, the binary will likely experience an accelerated merger time due to gravitational radiation, which could produce an increase in the predicted CO binary merger rate.

  10. LUT observations of the mass-transferring binary AI Dra

    Science.gov (United States)

    Liao, Wenping; Qian, Shengbang; Li, Linjia; Zhou, Xiao; Zhao, Ergang; Liu, Nianping

    2016-06-01

    Complete UV band light curve of the eclipsing binary AI Dra was observed with the Lunar-based Ultraviolet Telescope (LUT) in October 2014. It is very useful to adopt this continuous and uninterrupted light curve to determine physical and orbital parameters of the binary system. Photometric solutions of the spot model are obtained by using the W-D (Wilson and Devinney) method. It is confirmed that AI Dra is a semi-detached binary with secondary component filling its critical Roche lobe, which indicates that a mass transfer from the secondary component to the primary one should happen. Orbital period analysis based on all available eclipse times suggests a secular period increase and two cyclic variations. The secular period increase was interpreted by mass transfer from the secondary component to the primary one at a rate of 4.12 ×10^{-8}M_{⊙}/yr, which is in agreement with the photometric solutions. Two cyclic oscillations were due to light travel-time effect (LTTE) via the presence of two cool stellar companions in a near 2:1 mean-motion resonance. Both photometric solutions and orbital period analysis confirm that AI Dra is a mass-transferring binary, the massive primary is filling 69 % of its critical Roche lobe. After the primary evolves to fill the critical Roche lobe, the mass transfer will be reversed and the binary will evolve into a contact configuration.

  11. Gravitational waves from spinning compact binaries in hyperbolic orbits

    Science.gov (United States)

    De Vittori, Lorenzo; Gopakumar, Achamveedu; Gupta, Anuradha; Jetzer, Philippe

    2014-12-01

    Compact binaries in hyperbolic orbits are plausible gravitational-wave (GW) sources for the upcoming and planned GW observatories. We develop an efficient prescription to compute post-Newtonian (PN)-accurate ready-to-use GW polarization states for spinning compact binaries, influenced by the dominant-order spin-orbit interactions, in hyperbolic orbits. This is achieved by invoking the 1.5PN-accurate quasi-Keplerian parametrization for the radial sector of the orbital dynamics. We probe the influences of spins and the gravitational radiation reaction on h+ and h× during the hyperbolic passage. It turns out that both polarization states exhibit the memory effect for GWs from spinning compact binaries in hyperbolic orbits. In contrast, only the cross-polarization state exhibits the memory effect for GWs from nonspinning compact binaries. Additionally, we compute 1PN-accurate amplitude corrected GW polarization states for hyperbolic nonspinning compact binaries in a fully parametric manner and perform initial comparisons with the existing waveforms.

  12. Presence of mixed modes in red giants in binary systems

    Directory of Open Access Journals (Sweden)

    Themeßl Nathalie

    2017-01-01

    Full Text Available The frequencies of oscillation modes in stars contain valueable information about the stellar properties. In red giants the frequency spectrum also contains mixed modes, with both pressure (p and gravity (g as restoring force, which are key to understanding the physical conditions in the stellar core. We observe a high fraction of red giants in binary systems, for which g-dominated mixed modes are not pronounced. This trend leads us to investigate whether this is specific for binary systems or a more general feature. We do so by comparing the fraction of stars with only p-dominated mixed modes in binaries and in a larger set of stars from the APOKASC sample. We find only p-dominated mixed modes in about 50% of red giants in detached eclipsing binaries compared to about 4% in the large sample. This could indicate that this phenomenon is tightly related to binarity and that the binary fraction in the APOKASC sample is about 8%.

  13. Binary black hole coalescence in semianalytic puncture evolution

    International Nuclear Information System (INIS)

    Gopakumar, Achamveedu; Schaefer, Gerhard

    2008-01-01

    Binary black hole coalescence is treated semianalytically by a novel approach. Our prescription employs the conservative Skeleton Hamiltonian that describes orbiting Brill-Lindquist wormholes (termed punctures in numerical relativity) within a waveless truncation to the Einstein field equations [G. Faye, P. Jaranowski, and G. Schaefer, Phys. Rev. D 69, 124029 (2004)]. We incorporate, in a transparent Hamiltonian way and in Burke-Thorne gauge structure, the effects of gravitational radiation reaction into the above Skeleton dynamics with the help of 3.5PN accurate angular momentum flux for compact binaries in quasicircular orbits to obtain a semianalytic puncture evolution to model merging black hole binaries. With the help of the TaylorT4 approximant at 3.5PN order, we perform a first-order comparison between gravitational-wave phase evolutions in numerical relativity and our approach for equal-mass binary black holes. This comparison reveals that a modified Skeletonian reactive dynamics that employs flexible parameters will be required to prevent the dephasing between our scheme and numerical relativity, similar to what is pursued in the effective one-body approach. A rough estimate for the gravitational waveform associated with the binary black hole coalescence in our approach is also provided

  14. EVOLUTION OF A RING AROUND THE PLUTO–CHARON BINARY

    Energy Technology Data Exchange (ETDEWEB)

    Bromley, Benjamin C. [Department of Physics and Astronomy, University of Utah, 115 S 1400 E, Rm 201, Salt Lake City, UT 84112 (United States); Kenyon, Scott J., E-mail: bromley@physics.utah.edu, E-mail: skenyon@cfa.harvard.edu [Smithsonian Astrophysical Observatory, 60 Garden St., Cambridge, MA 02138 (United States)

    2015-08-10

    We consider the formation of satellites around the Pluto–Charon binary. An early collision between the two partners likely produced the binary and a narrow ring of debris, out of which arose the moons Styx, Nix, Kerberos, and Hydra. How the satellites emerged from the compact ring is uncertain. Here we show that a particle ring spreads from physical collisions and collective gravitational scattering, similar to migration. Around a binary, these processes take place in the reference frames of “most circular” orbits, akin to circular ones in a Keplerian potential. Ring particles damp to these orbits and avoid destructive collisions. Damping and diffusion also help particles survive dynamical instabilities driven by resonances with the binary. In some situations, particles become trapped near resonances that sweep outward with the tidal evolution of the Pluto–Charon binary. With simple models and numerical experiments, we show how the Pluto–Charon impact ring may have expanded into a broad disk, out of which grew the circumbinary moons. In some scenarios, the ring can spread well beyond the orbit of Hydra, the most distant moon, to form a handful of smaller satellites. If these small moons exist, New Horizons will find them.

  15. Binary pulsars as probes of a Galactic dark matter disk

    Science.gov (United States)

    Caputo, Andrea; Zavala, Jesús; Blas, Diego

    2018-03-01

    As a binary pulsar moves through a wind of dark matter particles, the resulting dynamical friction modifies the binary's orbit. We study this effect for the double disk dark matter (DDDM) scenario, where a fraction of the dark matter is dissipative and settles into a thin disk. For binaries within the dark disk, this effect is enhanced due to the higher dark matter density and lower velocity dispersion of the dark disk, and due to its co-rotation with the baryonic disk. We estimate the effect and compare it with observations for two different limits in the Knudsen number (Kn). First, in the case where DDDM is effectively collisionless within the characteristic scale of the binary (Kn ≫ 1) and ignoring the possible interaction between the pair of dark matter wakes. Second, in the fully collisional case (Kn ≪ 1), where a fluid description can be adopted and the interaction of the pair of wakes is taken into account. We find that the change in the orbital period is of the same order of magnitude in both limits. A comparison with observations reveals good prospects to probe currently allowed DDDM models with timing data from binary pulsars in the near future. We finally comment on the possibility of extending the analysis to the intermediate (rarefied gas) case with Kn ∼ 1.

  16. Stability studies of colloidal silica dispersions in binary solvent mixtures

    International Nuclear Information System (INIS)

    Bean, Keith Howard

    1997-01-01

    A series of monodispersed colloidal silica dispersions, of varying radii, has been prepared. These particles are hydrophilic in nature due to the presence of surface silanol groups. Some of the particles have been rendered hydrophobic by terminally grafting n-alkyl (C 18 ) chains to the surface. The stability of dispersions of these various particles has been studied in binary mixtures of liquids, namely (i) ethanol and cyclohexane, and (ii) benzene and n-heptane. The ethanol - cyclohexane systems have been studied using a variety of techniques. Adsorption excess isotherms have been established and electrophoretic mobility measurements have been made. The predicted stability of the dispersions from D.V.L.O. calculations is compared to the observed stability. The hydrophilic silica particles behave as predicted by the calculations, with the zeta potential decreasing and the van der Waals attraction increasing with increasing cyclohexane concentration. The hydrophobic particles behave differently than expected, and the stability as a function of solvent mixture composition does not show a uniform trend. The effect of varying the coverage of C 18 chains on the surface and the effect of trace water in the systems has also been investigated. Organophilic silica dispersions in benzene - n-heptane solvent mixtures show weak aggregation and phase separation into a diffuse 'gas-like' phase and a more concentrated 'liquid-like' phase, analogous to molecular condensation processes. Calculations of the van der Waals potential as a function of solvent mixture composition show good agreement with the observed stability. Determination of the number of particles in each phase at equilibrium allows the energy of flocculation to be determined using a simple thermodynamic relationship. Finally, the addition of an AB block copolymer to organophilic silica particles in benzene n-heptane solvent mixtures has been shown to have a marked effect on the dispersion stability. This stability

  17. Swelling and mechanical properties of hydrogels composed of binary blends of inter-linked pH-responsive microgel particles.

    Science.gov (United States)

    Milani, Amir H; Bramhill, Jane; Freemont, Anthony J; Saunders, Brian R

    2015-04-07

    We show that a new type of hydrogel can be prepared by covalently inter-linking binary blends of microgel (MG) particles and that the swelling ratio and modulus of the gels can be predicted from their composition. In previous work we established that physical gels of glycidyl methacrylate (GMA) functionalised poly(methyl methacrylate-co-methacrylic acid-co-ethyleneglycol dimethacrylate) microgel particles (GMA-MG) could be covalently inter-linked to give hydrogels, termed doubly crosslinked microgels, DX MGs. We build on this concept here by investigating the properties of DX MGs containing binary blends of GMA-MG particles and glycidyl oligo(ether ester) acrylate-functionalised microgel particles (GOE-MG). These new hydrogels were assembled by inter-linking nanoscale MG building blocks in the absence of small molecule monomers or crosslinkers. The volume fraction of GMA-MG particles used to prepare the GOE-GMA DX MGs was systematically varied. Rheology data showed that inclusion of GMA-MG and GOE-MG within the GOE-GMA DX MGs increased the modulus and yield strain, respectively, compared to the values measured for the respective physical gels. The data for the covalent GOE-GMA DX MG gels showed that the ductility increased with increasing GOE-MG content. GOE provided covalent inter-linking of the MG particles and also acted as a lubricant between particles due to its low Tg. By demonstrating compositionally determined swelling and mechanical properties for DX MG gels prepared using binary blends of MG particles, this study introduces a new, widely applicable, hydrogel construction assembly concept that is not available for conventional hydrogels.

  18. Disordered strictly jammed binary sphere packings attain an anomalously large range of densities

    Science.gov (United States)

    Hopkins, Adam B.; Stillinger, Frank H.; Torquato, Salvatore

    2013-08-01

    Previous attempts to simulate disordered binary sphere packings have been limited in producing mechanically stable, isostatic packings across a broad spectrum of packing fractions. Here we report that disordered strictly jammed binary packings (packings that remain mechanically stable under general shear deformations and compressions) can be produced with an anomalously large range of average packing fractions 0.634≤ϕ≤0.829 for small to large sphere radius ratios α restricted to α≥0.100. Surprisingly, this range of average packing fractions is obtained for packings containing a subset of spheres (called the backbone) that are exactly strictly jammed, exactly isostatic, and also generated from random initial conditions. Additionally, the average packing fractions of these packings at certain α and small sphere relative number concentrations x approach those of the corresponding densest known ordered packings. These findings suggest for entropic reasons that these high-density disordered packings should be good glass formers and that they may be easy to prepare experimentally. We also identify an unusual feature of the packing fraction of jammed backbones (packings with rattlers excluded). The backbone packing fraction is about 0.624 over the majority of the α-x plane, even when large numbers of small spheres are present in the backbone. Over the (relatively small) area of the α-x plane where the backbone is not roughly constant, we find that backbone packing fractions range from about 0.606 to 0.829, with the volume of rattler spheres comprising between 1.6% and 26.9% of total sphere volume. To generate isostatic strictly jammed packings, we use an implementation of the Torquato-Jiao sequential linear programming algorithm [Phys. Rev. EPLEEE81539-375510.1103/PhysRevE.82.061302 82, 061302 (2010)], which is an efficient producer of inherent structures (mechanically stable configurations at the local maxima in the density landscape). The identification and

  19. Disordered strictly jammed binary sphere packings attain an anomalously large range of densities.

    Science.gov (United States)

    Hopkins, Adam B; Stillinger, Frank H; Torquato, Salvatore

    2013-08-01

    Previous attempts to simulate disordered binary sphere packings have been limited in producing mechanically stable, isostatic packings across a broad spectrum of packing fractions. Here we report that disordered strictly jammed binary packings (packings that remain mechanically stable under general shear deformations and compressions) can be produced with an anomalously large range of average packing fractions 0.634≤φ≤0.829 for small to large sphere radius ratios α restricted to α≥0.100. Surprisingly, this range of average packing fractions is obtained for packings containing a subset of spheres (called the backbone) that are exactly strictly jammed, exactly isostatic, and also generated from random initial conditions. Additionally, the average packing fractions of these packings at certain α and small sphere relative number concentrations x approach those of the corresponding densest known ordered packings. These findings suggest for entropic reasons that these high-density disordered packings should be good glass formers and that they may be easy to prepare experimentally. We also identify an unusual feature of the packing fraction of jammed backbones (packings with rattlers excluded). The backbone packing fraction is about 0.624 over the majority of the α-x plane, even when large numbers of small spheres are present in the backbone. Over the (relatively small) area of the α-x plane where the backbone is not roughly constant, we find that backbone packing fractions range from about 0.606 to 0.829, with the volume of rattler spheres comprising between 1.6% and 26.9% of total sphere volume. To generate isostatic strictly jammed packings, we use an implementation of the Torquato-Jiao sequential linear programming algorithm [Phys. Rev. E 82, 061302 (2010)], which is an efficient producer of inherent structures (mechanically stable configurations at the local maxima in the density landscape). The identification and explicit construction of binary packings

  20. Low-latency analysis pipeline for compact binary coalescences in the advanced gravitational wave detector era

    International Nuclear Information System (INIS)

    Adams, T; Buskulic, D; Germain, V; Marion, F; Mours, B; Guidi, G M; Montani, M; Piergiovanni, F; Wang, G

    2016-01-01

    The multi-band template analysis (MBTA) pipeline is a low-latency coincident analysis pipeline for the detection of gravitational waves (GWs) from compact binary coalescences. MBTA runs with a low computational cost, and can identify candidate GW events online with a sub-minute latency. The low computational running cost of MBTA also makes it useful for data quality studies. Events detected by MBTA online can be used to alert astronomical partners for electromagnetic follow-up. We outline the current status of MBTA and give details of recent pipeline upgrades and validation tests that were performed in preparation for the first advanced detector observing period. The MBTA pipeline is ready for the outset of the advanced detector era and the exciting prospects it will bring. (paper)