DDS System Research Articles

On the dispersionless Davey-Stewartson hierarchy: the tau function, the Riemann-Hilbert problem and the Hamilton-Jacobi theory

The dDS (dispersionless Davey-Stewartson) hierarchy is constructed by two eigenfunctions of a special Hamiltonian vector field. This hierarchy consists of the infinite symmetries of the dDS system. Further, this paper explores the tau function, the Riemann-Hilbert problem and Hamilton-Jacobi theory related to dDS hierarchy.

Constructing and characterizing various multi-component crosslinked epoxy resins based on molecular dynamics simulations with a curing reaction model

Epoxy resins are extensively used as the matrix for carbon-fiber-reinforced plastic (CFRP) in commercial airplanes due to their outstanding thermomechanical properties. Until now, few researchers have simulated multicomponent epoxy resins. In this work, the impact of stoichiometric variations in the base resins in the Di Glycidyl Ether of Bisphenol A (DGEBA)/Tetra Glycidyl Diamino Diphenyl Methane (TGDDM)/4,4′-Diamino Diphenyl Sulfone (4,4′-DDS) system on the curing process and thermomechanical properties is investigated. When the proportions of each component are comparable, the curing process is primarily determined initially by the component with a lower activation energy and subsequently by the component with a relatively greater quantity during the high conversion rate stage. Furthermore, a higher proportion of TGDDM in the DGEBA/TGDDM/4,4′-DDS system results in an increased number of ring structures, which in turn leads to enhanced thermomechanical properties. Our Python-LAMMPS algorithm can be further developed for designing new multi-component epoxy resin materials.

Development of Anti-aging Cosmetics Using Chitosan/ γ-Cyclodextrin/Fucoidan Nanoparticles (Nanogel) Based on the Drug Delivery System

Purpose: This study aimed to develop MARINAVI-FD, a cosmetic material containing γ-cyclodextrin/chitosan/fucoidan nanoparticles, i.e., CH-γ-CD-Fu (Nanogel) based on the DDS system, and anti-aging cosmetics that have proven antioxidant and moisturizing effects.Methods: CH-γ-CD-Fu (nanogel) was identified through electron microscope (scanning electron microscope) analysis and nanoparticle size analysis (dynamic light scattering). Radical scavenging DPPH and ABTS assays were performed. Skin keratinocytes (HaCat cells) was assessed by the MTT assay, and the moisturizing effect was evaluated through enzyme-linked immunosorbent assay. Temperature and storage conditions were checked for the stability of the formulation. In the human body application test, Moisture Meter D Compact device was used.Results: The CH-γ-CD-Fu (Nanogel) has confirmed particle size of approximately 500 nm. In the DPPH and ABTS assays, compared with Fu (foucoidan), the CH-γ-CD-Fu (nanogel) showed higher scavenging ability at treatment concentration of 15.625–500 μg/mL. CH-γ-CD-Fu (Nanogel) showed a survival rate of >80% in skin keratinocytes (HaCat cells) up to a concentration of 5,000 μg/mL. In the measurement of hyaluronic acid production, CH-γ-CD-Fu (Nanogel) showed better production at 194.87 ng/mL than at 121.47 ng/mL at a concentration of 200 μg/mL in the control group. The stability of skin and cream formulations of anti-aging cosmetics containing MARINAVI-FD was confirmed. The moisturizing effect was observed 2.5 mm depth of skin human application.Conclusion: In this study, CH-γ-CD-Fu (nanogel) was used to materialize into anti-aging cosmetics.

A crop water stress index based internet of things decision support system for precision irrigation of wine grape

The goal of irrigation for wine grape grown in arid or semiarid regions is to sustain vine survival and to optimize berry attributes for quality wine production. Precision irrigation of wine grape is impeded by the lack of a smart, decision support system (DSS) to remotely monitor vine water status. The objectives of this study were to: develop and field test an Internet of Things (IoT) DSS system for precision irrigation of wine grape. The IoT system was comprised of a suite of in situ sensors used to monitor real-time weather conditions, grapevine canopy temperature, soil moisture, and irrigation amount. Sensor data were collected and stored on a field deployed data logger that calculated a daily thermal Crop Water Stress Index (CWSI) for grapevine using a neural network model with real-time sensor data model inputs. The data logger also hosted, via a cellular modem, webpages showing a running, 12-day history of daily CWSI, fraction of available soil moisture (fASW), irrigation amount, and other sensor data. The webpages were accessible to vineyard managers via cell phone or computer. The CWSI based IoT DDS system was installed at two small acreage, commercial estate vineyards in southwestern Idaho USA over four growing seasons. At each vineyard site, the DSS was used daily by the vineyard irrigation manager to schedule irrigation events. Neither vineyard manager used any other quantitative vine water status monitoring tool for irrigation management decisions. The midday leaf water potential (LWP) of grapevines was routinely measured by research project personnel. Data collected over the study period at each vineyard showed a significant (p < 0.001) correlation with LWP and fASW, providing evidence that, under the conditions of this study, the daily CWSI based IoT provided automated, remote monitoring of vine water status. Both vineyard managers reported daily use of the DSS for irrigation scheduling decisions. Over the four-year study, each vineyard manager was able to maintain consistent seasonal average CWSI daily values and irrigation application amounts, despite yearly differences in climatic conditions. The results of this study demonstrate that a CWSI based IoT DSS can be used for precision irrigation of wine grape in a commercial vineyard under semiarid growing conditions. The CWSI based IoT DSS used a unique combination of neural network modeling, edge computing, and IoT for real-time vine water stress monitoring for precision irrigation.

Improving diagnostic decision support through deliberate reflection: a proposal.

Digital decision support (DDS) is expected to play an important role in improving a physician's diagnostic performance and reducing the burden of diagnostic error. Studies with currently available DDS systems indicate that they lead to modest gains in diagnostic accuracy, and these systems are expected to evolve to become more effective and user-friendly in the future. In this position paper, we propose that a way towards this future is to rethink DDS systems based on deliberate reflection, a strategy by which physicians systematically review the clinical findings observed in a patient in the light of an initial diagnosis. Deliberate reflection has been demonstrated to improve diagnostic accuracy in several contexts. In this paper, we first describe the deliberate reflection strategy, including the crucial element that would make it useful in the interaction with a DDS system. We examine the nature of conventional DDS systems and their shortcomings. Finally, we propose what DDS based on deliberate reflection might look like, and consider why it would overcome downsides of conventional DDS.

On the dispersionless Davey–Stewartson hierarchy: Zakharov–Shabat equations, twistor structure, and Lax–Sato formalism

AbstractIn this paper, we continue the study of the Davey–Stewartson system, which is one of the most important (2 + 1)‐dimensional integrable models. As we showed in the previous paper, the dDS (dispersionless Davey–Stewartson) system arises from Hamiltonian vector fields Lax pair. A new hierarchy of compatible partial differential equations (PDEs) defining infinitely many symmetries, which is associated with the dDS system, is defined in this paper. We show that this hierarchy arises from the commutation condition of a particular series of one‐parameter Hamiltonian vector fields.

Curing kinetics and thermal properties of imide containing phthalonitrile resin using aromatic amines

Due to their outstanding properties, phthalonitrile based polymers plays an important role in high performance advanced materials evaluated depending upon their curing process and mechanism. Henceforth it is necessary to understand the curing kinetics of bisphthalonitrile monomer having imide linkage using 4, 4’-diaminodiphenylsulfone (DDS) as curing agent for further investigations. Thus, curing kinetics was investigated by recording non-isothermal differential scanning calorimetric (DSC) scans at heating rates of 5 °C, 10 °C, 15 °C and 20 °C/min. Activation energy for bisphthalonitrile/4, 4’-diaminodiphenylsulfone (DDS) system was calculated using Starink method and results give a substantial evidence that Arrhenius activation energy (Ea) are certainly dependent on the structure of monomer and curing agent. The cured FIPN/DDS, ODPA-PN/ DDS systems show comparable high thermal stability and elevated glass transition temperature as compared to Bis-ADPN/ DDS composition. Subsequently, this composition exhibits comparative heat resistance and improved moisture resistance.

On the dispersionless Davey–Stewartson system: Hamiltonian vector field Lax pair and relevant nonlinear Riemann–Hilbert problem for dDS-II system

In this paper, the semiclassical limit of Davey-Stewartson systems are studied. It shows that these dispersionless limited integrable systems of hydrodynamic type, which are defined as dDS (dispersionless Davey-Stewartson) systems, are arisen from the commutation condition of Lax pairs of one-parameter vector fields. The relevant nonlinear Riemann-Hilbert problems with some symmetries for the dDS-II system are also constructed. This kind of Riemann-Hilbert problems are meaningful for applying the formal inverse scattering transform method, recently developed by Manakov and Santini, to study the dDS-II system .

A new type of double dispersion system for water control in fossil hydrogen energy development

Water cut is generally rising with the increase of water injection during water flooding development of fossil hydrogen energy reservoir. Conventional chemical profile control agents fail to work for a long time because they are easily affected by the temperature and salinity of fossil hydrogen energy reservoir to form crossflow channel. In this paper, a new dual-disperse profile control agent and flooding system (DDS) is proposed, which uses polymers and microspheres to plug polymer crossflow and improve oil recovery in fossil hydrogen energy development. The viscosity, suspension property, thermal stability and microsphere size expansion of the DDS are tested, and the oil displacement performance is evaluated. The results show that the viscosity of polymer solution is not affected by the addition of microspheres, and the DDS system has good suspension and thermal stability. Due to the adsorption of microspheres in polymers, the particle size of microspheres tends to increase with time. But the expansion slows down gradually, which is beneficial to deep migration. In terms of plugging efficiency, the optimum concentration of DDS is 1500 mg/L polymer and 500 mg/L microsphere, and the optimum injection volume is 0.5Pv. Compared with single polymer flooding system, the new dual dispersion system has better washing resistance and enhanced oil recovery in fossil hydrogen energy development.

The effect of a novel phosphorus-nitrogen reactive flame retardant curing agent on the performance of epoxy resin

A phosphorus-nitrogen reactive flame retardant curing agent poly-(isophorondiamine spirocyclic pentaerythritol bisphosphonate) (PIPSPB) was synthesized. The chemical structure of the obtained compound was identified by FTIR, 1HNMR, and mass spectroscopies. Different proportions of DDS and PIPSPB were compounded as the curing agents to prepare a series of flame retardant epoxy resins with different phosphorus contents. The curing behavior of E-44/PIPSPB + DDS system was studied by DSC. A series of tests were conducted to characterize E-44/PIPSPB + DDS thermosetting system’s performance. The result demonstrates that the residual carbon content of EP/PIPSPB + DDS system is obviously higher than that of EP/DDS system after 500 °C with the increase of phosphorus content in the system, and the heat release rate of the system during combustion is significantly reduced. The generated phosphorus-containing carbon layer is obviously foamed, which shows that the flame retardancy of the system is the result of the combined action of condensed phase and gas phase. When the phosphorus content is 1.77wt%, EP-3 successfully passed UL94 V-0 flammability rating, the LOI value was as high as 29%, the impact strength and tensile strength of it were 6.08KJ/m2 and 49.10MPa respectively, the adhesive strength could reach 13.89 MPa, the system presents a good overall performance.

Design and development of an interactive mobile-based decision support system for selecting higher education studies

Abstract This work is an attempt to contribute to the knowledge and guidance of young people (lyceum graduates, higher education students and recent graduates) regarding important issues related to their career and vocational prospects. These issues are related to major relevant questions such as 'what' and 'where' to study, as well as the contents and the prospects of all provided specializations by the departments of Greek institutes of higher education. This article focuses on the analysis and the design of a mobile-based decision support system (DSS) to assist its users in getting thoroughly informed about HE studies in Greece, and eventually in choosing their vocational prospects. An extensive literature and applications review has revealed that there are no such DDS systems, giving to this work an innovative character. The article contains all main elements of system's architecture and design including the essential technical information, presents the main features and representative screenshots of the mobile-based application and comes to conclusions and future suggested work.

Study on the DDS Network Information Security Technology

The paper firstly analyzes security and stability existed in the DDS network, and then finds that present DDS regulations cannot guarantee information’s confidentiality and integrity when facing an attack. Based on this, the paper puts forward a core thought of data analysis. According to the draft of DDS information security regulation, the paper analyzes information security threats that the DDS system must face, provides corresponding information security strategies in accordance with data granularity and operation means, and designs and realizes an information security model based on DDS. The security model there into is divided into three levels: boundary security, transmission security and data application security of fine granularity. At the same time, the paper also analyzes several important elements which influence DDS network security in detail, and then designs again the data-centered publication/subscription model. Finally, through the model testing by a lot of experiments, the experimental results show that: the model not only largely improves security of DDS network information, but also has already promoted stability and reliability of data transmission process.

Efectos de dos sistemas de labranza sobre poblaciones de arroz rojo (Oryza sativa L.) en un agroecosistema arrocero inundado.

Effects of two tillage systems on red rice (Oryza sativa L.) populations in a flooded rice agroecosystem. The influence of two tillage systems was evaluated on red rice (Oryza sativa L.) populations and other frequent weeds in rice agroecosystems throughout four consecutive cycles of commercial flooded rice. In order to estimate the seed bank size, soil samples from three depths (0 to 5, 5 to 20 and 20 to 40 cm) were taken at the beginning of each crop cycle. The density of the most abundant weeds in the crop area was also measured. In both tillage systems there were significant differences in emerged weeds and seed banks. While the red rice seed bank and its emerged populations on the field presented incremental trends in conventional mechanized sowing (CMS), a progressive decrease in bank size and a lower density was observed in direct seeding into stubble (DSS), during cycles in which no tillage was used. Populations of annual sedges like Cyperus spp. and Fimbristylis milliaceae increased in both tillage systems, with greater intensity in CMS. The vertical distribution of the weed seed bank in the soil was also different for both tillage systems. In DSS more than 66% of the red rice seed bank and 82% of the germinated seeds were found within the first five cm of the soil profile. It is concluded that the DDS system promotes favorable conditions to maintain control over red rice populations and other weeds in flooded rice.

Artesunate-clindamycin multi-kinetics and site-specific oral delivery system for antimalaric combination products

The aim of this work was to study a multi-kinetics and site-specific oral antimalaria drug delivery system (MKS_DDS), containing artesunate and clindamycin, based on the Dome Matrix® module assembly technology. The MKS_DDS assembled system comprises of four modules, i.e., two controlled release (CR) modules for delivery of 160 mg of clindamycin phosphate, one immediate release module containing 50 mg of artesunate and one immediate release module containing 80 mg of clindamycin phosphate. These modules have been assembled in stacked and void configurations. The void configuration is able to float and showed gastro-retentive behavior. The MKS_DDS was investigated for its mechanical characteristics, system behavior during release, drug release rate and mechanism. A bioavailability study (dogs) showed that the clindamycin plasma curve of the MKS_DDS system exhibited a quasi constant release rate, up to 8 h. The MKS_DDS system containing clindamycin and artesunate allows the use of one tablet containing one immediate release dose of artesunate and of clindamycin and a portion of clindamycin released over a prolonged time, by exploiting the gastro-retentive properties of a floating system.

Commentary: Diagnostic change and the increased prevalence of autism

Commentary: Diagnostic change and the increased prevalence of autism

Cure kinetics and catalyzed effect of hydroxyl group of LC diglycidyl ether of bisphenol‐S with aromatic diamines

AbstractThe curing reactions of liquid crystalline 4,4′‐bis‐(2,3‐epoxypropyloxy)‐sulfonyl‐bis(1,4‐phenylene) (p‐BEPSBP) with 4,4′‐diaminodiphenylmethane (DDM) and 4,4′‐diaminodiphenylsulfone (DDS) were investigated by nonisothermal differential scanning calorimeter (DSC). The relationships of Ea with the conversion α in the curing process were determined. The catalyzed activation of hydroxyl group for curing reaction of epoxy resins with amine in DSC experiment was discussed. The results show that these curing reactions can be described by the autocatalytic Šesták‐Berggren model. The curing technical temperature and parameters were obtained, and the even reaction orders m, n, and ΔS for p‐BEPSBP/DDM and p‐BEPSBP/DDS are 0.35, 0.92, −81.94 and 0.13, 1.32, −24.45, respectively. The hydroxyl group has catalyzed activation for the epoxy–amine curing system in the DSC experiment. The average Ea of p‐BEPSBP/DDM is 67.19 kJ mol−1 and is 105.55 kJ mol−1 for the p‐BEPSBP/DDS system, but it is different for the two systems; when benzalcohol as hydroxyl group was added to the curing system, the average Ea of p‐BEPSBP/DDM decreases and increases for p‐BEPSBP/DDS. The crystalline phase had formed in the curing process and was fixed in the system. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Application of the Cozart DDS system to postmortem screening of drugs of abuse in vitreous humor

The analysis of drugs of abuse in human specimens is essential in forensic medicine. This study evaluated the use of Cozart DDS for postmortem screening of some drugs of abuse in vitreous humor (VH) prior to forensic autopsies. The Cozart DDS is an on-site drug detection system that has been validated for oral fluid. Seventy-one VH specimens were obtained from cadavers. Causes of death included injury, drug poisoning, natural disorders, and traffic accidents. The samples were tested for cannabis, cocaine, opiate, amphetamine, and methamphetamine. Thirty-three of 71 samples were positive for drugs of abuse (42% for cocaine, 28% for cannabis, 26% for opiates, and 3% for methamphetamine). The positive specimens for opiates and methamphetamine were reexamined by gas chromatography-mass spectrometry (GC-MS); benzoylecgonine (cocaine product) was detected by liquid chromatography-tandem mass spectrometry (LC-MS-MS). All positive results for cocaine or its products and opiates by the Cozart test were confirmed by MS analysis, whereas one positive result for methamphetamine was negative by MS. The Cozart DDS system is generally a useful screening test for VH specimens prior to autopsies, because of its simplicity and rapidness.

Novel nitrogen‐containing epoxy resin. II. Cure kinetics by differential scanning calorimetry

AbstractThe isothermal and nonisothermal cure behaviors of a novel nitrogen‐containing epoxy resin (XT resin) were studied by differential scanning calorimetry (DSC). Various kinetic parameters and details of cure process were obtained based on the Avrami theory. The results indicated that Avrami method is suitable for calculating the kinetic parameters up to the gel point at least. The apparent activation energy (Ea) for isothermal cure process was in agreement with that for nonisothermal cure process. Ea value in the early stage (78.5–81.0 KJ mol−1) was about three times than that in the later stage (23.3–26.5 KJ mol−1). The kinetic results from Avrami theory may present a combined effect of all factors, and which is helpful to understand the cure technique for XT–DDS system. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3483–3489, 2006

On the crystallization of calcium carbonate modulated by anionic surfactants

Crystallization experiments of calcium carbonate (CaCO 3) in the presence of different anionic surfactants are carried out by rapidly mixing CaCl 2 with Na 2CO 3 in aqueous solutions. The selected anionic surfactants are sodium dodecylsulfate (SDS), sodium dodecylsulfonate (DDS), and sodium dodecylbenzenesulfonate (SDBS), respectively. The concentration and the head group of the anionic surfactants intensively influence the crystalline phase and morphology of the precipitated crystals. When the concentration is as low as 0.05 mM, the crystal particles obtained in the presence of all the investigated anionic surfactants are rhombohedral calcite crystals. As the surfactant concentration is increased to 0.5 mM, vaterite crystals are produced in SDBS system, while for SDS and DDS systems, there is no obvious change both for the crystalline phase and morphology of CaCO 3. As the surfactant concentration is further increased to as high as 5 mM, vaterite particles are produced in SDBS system, and hollow-spherical calcite crystals obtained in the presence of SDS, whereas rhombohedral calcite crystals in DDS system. Possible formation mechanism of different CaCO 3 polymorphs from different anionic surfactants solutions is proposed based on the experimental results.

A New Dental Approach for Reducing Food Intake

A behavioral recommendation for weight loss is reduction of size of bites of food. This "proof of concept" study tested the efficacy of a new, patented, dental approach, the DDS System, for reducing food intake. This removable tool is inserted into the upper palate of the mouth, reducing the size of the oral cavity, thereby potentially reducing bite size. Thirty-two adults (18 to 65 years) with BMI between 27 and 40 were randomly assigned to the control or experimental conditions. Participants ate all meals and stayed between meals at a research center. Day 1 served as baseline for both groups. On Day 2, experimental participants utilized the tool during meals. Changes in subjective ratings of hunger and satiety were measured using visual analog scales before and after each meal. Food intake difference scores were calculated for each participant (Day 2 - Day 1). Analysis of covariance on difference scores, using baseline as a covariate, showed that the experimental group ate significantly less (p < 0.05) on the second day (M = -659.2 kcal/d) compared with the control group (M = -125.9 kcal/d). Analysis of covariance, with ratings on Day 1 as a covariate, revealed that the experimental and control group did not differ on visual analog scale difference scores (premeal - postmeal) from Day 1 to Day 2. These findings suggest that use of this tool during meals significantly reduced food intake. This reduction of food intake was not associated with changes in ratings of hunger or satiety.