Simple Diagram Research Articles

Vacuum seagull: Evaluating a three-loop Feynman diagram with three mass scales

We study a 3-loop 5-propagator Feynman Integral, which we call the vacuum seagull, with arbitrary masses and spacetime dimension using the Symmetries of Feynman Integrals method. It is our first example with potential numerators. We determine the associated group $G \subset GL(3)$ which happens to be 5 dimensional and the associated set of 5 differential equations. $G$ is determined by a geometric approach which we term "current freedom". We find the generic $G$-orbit to be co-dimension 0 and hence the method is maximally effective, and the diagram reduces to a line integral over simpler diagrams. For a reduced parameter space with 3 mass scales we are able to present explicit results in terms of special functions. This might be the first such example.

Developing a hazard analysis worksheet in a small food business with the application of a T-shaped matrix diagram

Based on the information obtained from quality/food safety managers, hazard analysis worksheets (HAWs) and flow diagrams were identified, using the ABCD method, as the elements which generate the most extended areas of food safety management systems (FSMSs) based on HACCP procedures. In order to simplify this part of documentation, a shortened form of HAWs designed on the basis of a T-shaped matrix diagram (T-HAWs) was developed. T-HAWs were implemented on a trial basis in three small food businesses (SFBs) for a period of six months. After five months, documentation users evaluated the suitability of both the classic and the new forms of HAWs. The evaluation results were expressed in a numerical form as the documentation usability index (DUI), which values for the classic HAWs amounted from 0.55 to 1.1, and for T-HAWs ranged from 1.3 to 1.8. Student's t-test confirmed the existence of significant differences of the DUI values between both evaluated forms of the HAWs.The study demonstrates that the FSMSs documentation area may be a subject of research aimed at simplifying and reducing the volume of system documents through the use of effective methods and management tools. The T-HAWs developed in this work, in combination with a simplified flow diagram, provided an opportunity for a significant reduction in the classic HACCP plan, which may facilitate the implementation and application of the Codex HACCP principles and HACCP-based procedures in SFBs. Even though the T-HAWs were positively assessed by the users of HACCP documentation, certain limitations were identified, therefore the results of this study should be regarded as preliminary investigations which require to be continued with a greater number of SFBs representing a greater range of food industry sectors included.

Homotopy Type of Intervals of the Second Higher Bruhat Orders

The higher Bruhat order is a poset generalizing the weak order on permutations. Another special case of this poset is an ordering on simple wiring diagrams. For this case, we prove that every interval is either contractible or homotopy equivalent to a sphere. This partially proves a conjecture due to Reiner. Our proof uses some tools developed by Felsner and Weil to study wiring diagrams.

Pure and Intense Green Upconversion Emission and Temperature Sensing Properties of Ba5Gd8Zn4O21:Ho3+/Yb3+ Nanophosphors

Ho3+/Yb3+ co-doped zincate Ba5Gd8Zn4O21 nanophosphors were successfully synthesized by solid-state reaction. The crystal structure and phase purity were measured by X-ray diffraction (XRD) and the luminescence spectra and CIE chromaticity were investigated. The results show that the upconversion (UC) luminescence intensities are heavily dependent on the rare-earth dopant concentration but the emission colors are almost the same. Both the green and red UC emissions under 980 nm excitation are shown to be two-photon processes independent of doping concentrations. Furthermore, the optical temperature sensing performance shows that Ho3+/Yb3+ co-doped Ba5Gd8Zn4O21 nanophosphors are promising candidates for room-temperature applications. The temperature quenching process of green UC emission was modeled using a simplified 4-level diagram and well explained by crossover process and thermal excitation.

Rare-earth free broadband Ca3Mg3P4O16:Mn2+ red phosphor: Synthesis and luminescence properties

Rare-earth-free red-emitting Ca3Mg3P4O16:Mn2+ (CMPO:Mn2+) phosphor is synthesized by high temperature solid-state reaction method in air. The crystal structures and luminescence properties are investigated. Broad emission band peaking at ~ 625nm of CMPO:Mn2+ phosphor with excitation 410nm is observed in the range of 510 − 790nm due to the 4T1(G) → 6A1 transition of the Mn2+ ion. The full width at half-maximum is ~ 120nm. Excitation bands are assigned to the [6A1 → 4E(4D), 4T2(D), [4A1(G), 4E(4G), and 4T1(G)] transitions, respectively. The optimal Mn2+ ion concentration in CMPO:Mn2+ phosphor is ~ 5mol%. The lifetime of CMPO:0.05Mn2+ phosphor is ~ 5.75ms. The luminous mechanism of Mn2+ ion in CMPO:Mn2+ phosphor is explained by Tanabe-Sugano diagram and the simple energy level diagram of Mn2+ ion. The paper content is helpful for the research of novel Mn2+-doped materials.

Climate information for building designers: a graphical approach

ABSTRACTDesigning for the climate-responsive built environment is not a new concept. Local climate played a significant part in ancient city and building designs. In contrast, modern built environment professionals increasingly use climate-modifying technologies to nullify the local climatic constraints. The lack of climate considerations is often associated with limited understanding of local climate. Although detailed quantitative climate information is available for thermal performance evaluation tools, its qualitative interpretation is often too simplified to inform design decisions at early design stage. This paper addresses the issues of climate data analysis and presentation, and uses simple graphics to inform building designers about the local climate and encourages them to consider climate in their designs. This paper takes the case of Brisbane's climate, illustrates it through simple diagrams, and redefines seasonal variation into different periods based on comfort conditions. This paper also discusses application of the information in climate-responsive design.

Evaluation of system performance by adding a fourth dimension to turbo code

SummaryDifferent forms of turbo codes (TCs) have already been used in the contemporary message transferring system for transmission of the protected information because of their astonishing bit error rate (BER) behavior. However, it suffers from poor “flattening effect” performance. To overcome this limitation, component encoders having higher memory elements or more number of component encoders may be considered. At the initial segment of this article, the proposal of binary 4‐dimensional turbo code (4D‐TC) with appropriate “generator polynomial” combination and suitable interleaver arrangement has been abridged in Third‐Generation Partnership Project standard. This is an amended form of 3‐dimensional turbo code where some part of the “parity bits” is re‐encoded by the third encoder, and rest part is re‐encoded by the fourth encoder consisting of single memory component. Afterwards, performance of the proposed structure has been assessed by varying block length, number of component encoders, puncturing rate, and channel condition. At the consequent segment, “constricted upper bound” on the BER performances of the 4D‐TC has been assessed by adopting an approach called simplified augmented state diagram. Moreover, an exhaustive analysis has been performed on the novel simplified augmented state diagram approach–based 4D‐TC by fluctuating several internal parameters of the code structure like generator polynomial combination, block length, puncturing rate, interleaver combination, and permeability rate. In this regard, the existing augmented state diagram approach has been considered for comparative analysis as well.

Fluorescence property of novel near-infrared phosphor Ca2MgWO6:Cr3+

A novel near infrared (NIR) emitting long-lasting phosphorescence (LLP) phosphors of Ca2MgWO6:Cr3+ were prepared by solid-state reaction in air. X-ray diffraction patterns showed that the obtained phosphors have a single-phase monoclinic structure and the incorporation of the dopants did not change the crystal structure. When excited at 371 nm, Ca2MgWO6:Cr3+ phosphors show characteristic broadband NIR fluorescence corresponding to the 4T2→4A2 transitions of Cr3+. The optimal Cr3+ doping concentration is 0.4% (mol). The critical distance between Cr3+ ions has been calculated and the concentration quenching type in Ca2MgWO6:Cr3+ was verified to be a dipole-dipole interaction. The optical spectra and the decay curves of the phosphors indicate that there exists efficient energy transfer from host to Cr3+ ions. The Ca2MgWO6:Cr3+ phosphors also exhibit NIR LLP phenomenon which is seldom presented in non-gallate phosphors. Finally, the possible fluorescence and LLP mechanism and possible energy transfer processes in Ca2MgWO6:Cr3+ phosphor are analyzed with simplified energy level diagrams.

Chemical variations within and between the clasts, and the matrix of the Abee enstatite chondrite suggest an impact-based differentiation mechanism

Abee is an enstatite chondrite breccia dominantly composed of kamacite, enstatite, silica, plagioclase, troilite and niningerite. Clasts are up to 220 mm long and vary in shape from angular to rounded. Some clasts are zoned with kamacite-enriched rims that follow the edge of the clast. Spatial compositional variations were examined in a small block to find out more about the petrological processes that produced this rock, particularly the relationship between the clasts, the matrix and the cores/rims of the zoned clasts. Compositional maps produced using a focussed-beam XRF were segmented into clasts and matrix, and rims and cores where possible. Compositions of most clasts, matrix and rim/cores define a simple, linear trend on simple variation diagrams. If it is assumed that all components were derived from an original homogeneous composition then the variation can be explained either by addition of kamacite or by loss of all other phases. Within this overall compositional variation the kamacite content generally increases as follows: matrix < large homogeneous clasts ≈ zoned clast cores < small homogeneous clasts ≈ zoned clast rims. Production of diversity by addition of kamacite to clasts and rim seems to require a complex history as the source cannot have been the current matrix. It is also difficult to produce the observed chemical variations and zoning by partial melting. However, differentiation by removal of all non-metallic phases may result from repeated impacts: Shock waves would deform kamacite whilst fracturing all other phases. The broken grains would then migrate towards the surface of the clasts where they would spall off into the matrix. This process would also lead to the observed rounding of some clasts. We propose that this shock-differentiation process be called ‘smithing’, as it resembles the ancient process of iron refining.

The localized skein algebra is Frobenius

When $A$ in the Kauffman bracket skein relation is a primitive $2N$th root of unity, where $N\geq 3$ is odd, the Kauffman bracket skein algebra $K_N(F)$ of a finite type surface $F$ is a ring extension of the $SL_2\mathbb{C}$-characters $\chi(F)$ of the fundamental group of $F$. We localize by inverting the nonzero characters to get an algebra $S^{-1}K_N(F)$ over the function field of the character variety. We prove that if $F$ is noncompact, the algebra $S^{-1}K_N(F)$ is a symmetric Frobenius algebra. Along the way we prove $K(F)$ is finitely generated, $K_N(F)$ is a finite rank module over $\chi(F)$, and the simple closed curves that make up any simple diagram on $F$ generate a finite field extension of $S^{-1}\chi(F)$ inside $S^{-1}K_N(F)$.

Energy transfer and 1.8 μm emission in Er3+/Tm3+ co-doped fluorogermanate glasses

The 1.8μm down-conversion emission properties of Er3+/Tm3+ co-doped fluorogermanate glasses are investigated under 980nm laser diode (LD) excitation in this paper. The glass properties are systematically evaluated by DSC, XRD, Raman techniques. The spectroscopic properties of Er3+ and Tm3+ including infrared down-conversion (DC) and visible up-conversion (UC) emissions are studied in detail. Meanwhile, the up-conversion emissions at 542nm, 654nm of Er3+ are suppressed with a high amount of Tm2O3 added. The Judd-Ofelt parameters and spontaneous transition probability of Tm3+ are illustrated for radiative properties. Besides, the absorption and emission cross sections of Tm3+ in Er3+/Tm3+ co-doped fluorogermanate glasses are provided as potential candidates for mid-infrared applications. The possible energy transfer mechanism is investigated via simplified energy level diagram, and energy transfer efficiency from Er3+ to Tm3+ is as high as 85.9%. In addition, the energy transfer parameters between Er3+ and Tm3+ are analyzed by the phonon sideband theory. The results indicate that the Er3+/Tm3+ co-doped fluorogermanate glasses have potential applications in mid-infrared lasers.

IR spectroscopic study of the displacement of an SF6 monolayer on graphite by Xe.

We report a study of displacement by xenon of a monolayer of sulphur hexafluoride initially condensed on a graphite surface. Earlier work showed that, below 112 K, Xe displaces SF6 almost completely in a first-order transition. Working at higher temperatures, we show that this system has a simple eutectic-like phase diagram, at least for SF6 not too dilute. In our experiment, both adsorbates are in equilibrium with their respective vapors in a cold cell. In our infrared reflection-absorption spectroscopy measurements, the SF6 coverage on the surface is monitored by the frequency shift due to dynamic dipole coupling of the collective mode of the strong SF6 ν3 vibrational resonance. Simulations relate this frequency shift to the SF6 areal density. Below T ≈ 134 K, with increasing Xe pressure, a small amount Xe dissolves in the solid SF6 monolayer preceding its displacement by a solid predominantly Xe monolayer in a first-order transition. Above 134 K, there is a weaker first-order transition to a mixed liquid monolayer, followed by continuous increase in Xe concentration. If the initial SF6 monolayer is near its melting line, the melting transition on adding Xe appears to become continuous.

A systematic review of the barriers affecting medication adherence in patients with rheumatic diseases.

Medication adherence is a crucial part in the management of rheumatic diseases, especially with many such patients requiring long-term medications. In this paper, we aim to systematically review the literature for the factors associated with medication adherence in the rheumatic patient population. We carried out a systematic literature search using PubMed®, PsychInfo® and Embase ® with relevant keywords and employed the PRISMA® criteria. We included English peer-reviewed articles that studied the factors affecting medication adherence in patients with rheumatic diseases, which were assessed by two independent reviewers. Hand searches were conducted and relevant factors were extracted and classified using the World Health Organization (WHO)'s five dimensions of medication adherence. A simple diagram was drawn to summarise the factors extracted. 1977 articles were identified and reviewed and 90 articles were found to be relevant. A total of 17 factors and 38 sub-factors were identified and categorized based on the WHO's five dimensions of medication adherence. A hand model for medication adherence was developed to succinctly summarise these dimension to remind clinicians the importance of medication adherence in daily practice. We conducted a systematic review on the various factors including patient, therapy, condition, health system and socioeconomic-related factors that affected medication adherence in rheumatic patients. We found 17 factors and 38 sub-factors that affected medication adherence in this population. This systematic review can facilitate future focused research in unexplored dimensions.

Formulation-Controlled Positive and Negative First Normal Stress Differences in Waterborne Hydrophobically Modified Ethylene Oxide Urethane (HEUR)-Latex Suspensions.

Hydrophobically modified ethylene oxide urethane (HEUR) associative thickeners are widely used to modify the rheology of waterborne paints. Understanding the normal stress behavior of the HEUR-based paints under high shear is critical for many applications such as brush drag and spreading. We observed that the first normal stress difference, N1, at high shear (large Weissenberg number) can be positive or negative depending on the HEUR hydrophobe strength and concentration. We propose that the algebraic sign of the N1 is primarily controlled by two factors: (a) adsorption of HEURs on the latex surface and (b) the ability of HEURs to form transient molecular bridges between latex particles. Such transient bridges are favored for dispersions with small interparticle distances and dense surface coverages; in these systems; HEUR-bridged latex microstructures flow-align in high shear and exhibit positive N1. In the absence of transient bridges (large interparticle distances, low surface coverage), the dispersion rheology is similar to that of weakly interacting spheres, exhibiting negative N1. The results are summarized in a simplified phase diagram connecting formulation, microstructure, and the N1 behavior.

On g m-boosted follower-amplifier and its novel circuit transformation based mid-band derivations

This brief paper investigates the small-signal mid-band behavior of g m-boosted follower-amplifiers which has not been explored previously and whose analysis is not available in text-books or any other source. Both g m-boosted source follower and g m-boosted emitter follower are considered in the mid-band analysis. A novel circuit/source transformation based “pictorial” technique with progressively simplified circuit diagrams is employed for this mid-band analysis which generally eliminates the need for solving nodal or mesh equations. Final expression is often achieved by inspection of the simplified circuit without the need for circuit analysis. The paper also discusses g m-boosted BiCMOS follower amplifier using substrate PNP device in a pure CMOS process. The analysis demonstrates that the unity gain accuracy of follower-amplifier can be considerably enhanced using the g m-boosting technique without sacrificing bandwidth.

Experimental evidence for diagramming benefits in science writing

Arguing for the need for a scientific research study (i.e. writing an introduction to a research paper) poses significant challenges for students. When faced with these challenges, students often generate overly safe replications (i.e. fail to find and include opposition to their hypothesis) or in contrast include no strong support for their hypothesis (i.e. relevant, valid evidence). How can we support novice scientists in generating and defending high quality hypotheses? A long history of research supports the affordances provided by structured representations of complex information. More recently, argument diagramming has gained traction in instruction for philosophy, social studies, and law. However, its effectiveness for supporting students in science is relatively untested. The purpose of the current study was to test the effectiveness of a simple argument diagram optimized for supporting students’ research writing in psychology. Two groups of undergraduate students in research methods lab courses were randomly assigned to diagramming support or no support. In the research papers, those given diagramming support were more likely to argue for an appropriately ‘risky’ hypothesis and wrote more about the relevance and validity of cited studies. Some of these gains show signs of transfer to a second paper written later in the course that did not require use of the diagramming tool.

Anaesthesia for cardioversion

External direct current (DC) cardioversion refers to the application of a synchronized electrical shock across a patient’s chest using a defibrillator. The aim being to convert abnormal tachyarrhythmias back into sinus rhythm. Anaesthetists are often requested to provide anaesthesia for cardioversion because it is an extremely stimulating and painful procedure, which requires an appropriate depth of anaesthesia to be tolerated without adverse psychological consequences.1 This may involve emergency scenarios in unfamiliar locations such as Coronary Care Units (CCUs) and Emergency Departments, as well as the more commonly performed elective case. Anaesthetists may also need to perform cardioversion themselves in theatre or Critical Care settings. An understanding of both the theoretical and practical aspects of this procedure are essential to perform cardioversion safely and hence form the basis of this review. The early 20th century saw a rapid expansion of the electrical power industry and accidents associated with electrocution. It soon became apparent that most deaths were due to ventricular fibrillation (VF). Ironically research at the time suggested that alternating current (AC) was more effective at terminating VF than DC. As a result the earliest defibrillators in the USA utilized AC shocks. In the USSR defibrillator development followed a different path, largely due to the work of Naum Gurvich.2 In 1939, Gurvich and Yuniev proposed using a single capacitor discharge to defibrillate VF. By 1952 Gurvich had designed the first commercially available transthoracic DC defibrillator that became rapidly utilized throughout the Soviet Union. It was only 10 yr later in 1962 that Lown reported the successful use of DC cardioversion to treat cardiac arrhythmias which revolutionized practice in the USA and elsewhere. ### Simple defibrillator function Modern defibrillators have become far more sophisticated than simple circuit diagrams suggest. They still rely on a power source which charges a capacitor, generating a potential difference …

L1157-B1, a factory of complex organic molecules in a solar-type star-forming region

Abstract We report on a systematic search for oxygen-bearing complex organic molecules (COMs) in the solar-like protostellar shock region L1157-B1, as part of the IRAM Large Program ‘Astrochemical Surveys At IRAM’. Several COMs are unambiguously detected, some for the first time, such as ketene H2CCO, dimethyl ether (CH3OCH3) and glycolaldehyde (HCOCH2OH), and others firmly confirmed, such as formic acid (HCOOH) and ethanol (C2H5OH). Thanks to the high sensitivity of the observations and full coverage of the 1, 2 and 3 mm wavelength bands, we detected numerous (∼10–125) lines from each of the detected species. Based on a simple rotational diagram analysis, we derive the excitation conditions and the column densities of the detected COMs. Combining our new results with those previously obtained towards other protostellar objects, we found a good correlation between ethanol, methanol and glycolaldehyde. We discuss the implications of these results on the possible formation routes of ethanol and glycolaldehyde.

An accurate and efficient approach to geometric modeling of undeformed chips in five-axis CNC milling

Many important and complex parts, such as aero-engine compressors and automotive punch dies, are often machined in five-axis computer numerically controlled (CNC) milling. To machine the parts with accurate dimensions and shapes and low machining costs it is necessary to construct 3D models of the finished parts in the geometric simulation and in-process workpiece models of the parts in the physical simulation of their five-axis milling. A kernel technique of the geometric and the physical simulations is to accurately and efficiently model the geometry of the workpiece material removed at every moment of the machining, which is the instantaneous, undeformed chip geometry. Although in the past decades much research has been conducted on modeling cutter swept volumes in CNC milling to represent the finished part geometry in the geometric simulation, it is very time consuming to calculate the instantaneous, undeformed chip geometries using the cutter swept volumes. Besides, the existing method of modeling undeformed chip geometry in three-axis milling cannot be used for that in five-axis milling. To address this problem, our work proposes an accurate and efficient approach. In this article, a generic theory about the boundary of the area covered by the instantaneous cutting edges on a workpiece layer at any moment is established, which is called the boundary theory. A simple diagram of determining the boundary is invented, which is called boundary construction diagram. This approach lays a theoretical foundation for the geometric and the physical simulations of five-axis milling and will significantly promote them for high performance machining in industry.

Numerical modeling of a compositional flow for chemical EOR and its stability analysis

A new two-dimensional surfactant flooding simulator for a three-component (water, petroleum, chemical), two-phase (aqueous, oleous) system in porous media is developed and analyzed. The compositional physical model is governed by a system of non-linear partial differential equations composed of Darcy’s and mass conservation equations. The system is then numerically solved by a finite difference method using the IMPEC (IMplicit Pressure and Explicit Concentration) scheme. Physical properties are described by a set of concentration-dependent algebraic equations. Additionally, a novel numerical stability analysis is presented in order to study the robustness of the new simulator. The oil recovery factor showed a strong dependency on the surfactant properties and phase behavior, which should be carefully evaluated. In order to achieve this, the new simulator utilizes and modifies a simplified ternary diagram to model accurately the component partitioning. Results showed that surfactant partitioning is the most relevant parameter in the recovery process. Numerically speaking, the simulator behaved according to the results obtained in the matrix stability analysis. Using the non-iterative IMPEC, a critical time value was found beyond which the system yielded large oscillatory values for the produced flowrates. The simulator can be employed to design and optimize chemicals used in enhanced oil recovery (EOR) processes before field application.