Controlling Toughness of Polymer-grafted Nanoparticle Composites for Impact Mitigation

Toughness in an entangled polymer network is typically controlled by the number of load-bearing topological constraints per unit volume. In this work, we demonstrate a new paradigm for controlling toughness...

Differences in the organisation of early pregnancy units and the effect of senior clinician presence, volume of patients and weekend opening on emergency hospital admissions: Findings from the VESPA Study

Objective To determine whether the participation of consultant gynaecologists in delivering early pregnancy care results in a lower rate of acute hospital admissions. Design Prospective cohort study and emergency hospital care audit; data were collected as part of the national prospective mixed-methods VESPA study on the “Variations in the organization of EPAUs in the UK and their effects on clinical, Service and PAtient-centred outcomes”. Setting 44 Early Pregnancy Assessment Units (EPAUs) across the UK randomly selected in balanced numbers from eight pre-defined mutually exclusive strata. Participants 6606 pregnant women (≥16 years old) with suspected first trimester pregnancy complications attending the participating EPAUs or Emergency Departments (ED) from December 2016 to July 2017. Exposures Planned and actual senior clinician presence, unit size, and weekend opening. Main outcome measures Unplanned admissions to hospital following any visit for investigations or treatment for first trimester complications as a proportion of women attending EPAUs. Results 205/6397 (3.2%; 95% CI 2.8–3.7) women were admitted following their EPAU attendance. The admission rate among 44 units ranged from 0% to 13.7% (median 2.8). Neither planned senior clinician presence (p = 0.874) nor unit volume (p = 0.247) were associated with lower admission rates from EPAU, whilst EPAU opening over the weekend resulted in lower admission rates (p = 0.027). 1445/5464 (26.4%; 95%CI 25.3 to 27.6) women were admitted from ED. There was little evidence of an association with planned senior clinician time (p = 0.280) or unit volume (p = 0.647). Keeping an EPAU open over the weekend for an additional hour was associated with 2.4% (95% CI 0.1% to 4.7%) lower odds of an emergency admission from ED. Conclusions Involvement of senior clinicians in delivering early pregnancy care has no significant impact on emergency hospital admissions for early pregnancy complications. Weekend opening, however, may be an effective way of reducing emergency admissions from ED.

The amount of heat input to the weld per unit length and per unit volume

This paper presents a comparative analysis of heat input per unit length and per unit volume for selected methods of welding. The purpose of the analysis is to assess the usability of calculating heat input per volume unit. The interpretation of heat input per unit length according to the standards: QW-409.1 of ASME IX, EN ISO 1011-1 is discussed. The concept of calculating heat input per unit volume is described. For exemplary padded welds and spot welded joints, the heat input values were calculated in accordance with the above-mentioned standards and based on the concept of heat input per unit volume. The study showed a lack of consistency between the individual standards in the interpretation of the heat input. In addition, the practical application of the heat input per unit volume method in calculating the actual amount of heat introduced into the weld was justified.

Displacement prediction and optimization of a non-circular planetary gear hydraulic motor

The non-circular planetary gear hydraulic motor is a low-speed and high-torque hydraulic motor with excellent performance. It has the characteristics of a wide speed range, low weight and is widely used in various fields. Aiming to solve the problem of there being no intuitive formula for calculating the displacement of the non-circular planetary gear hydraulic motor at present, based on the analysis of the effects of structural parameters on the displacement of the motor, this paper proposes a formula for calculating the displacement of a non-circular planetary gear hydraulic motor when the pitch curve of the sun wheel is a high-order ellipse. The formula allows the direct calculation and prediction of the displacement of the motor. To improve the unit volume displacement of the hydraulic motor (which determines the power density of the motor), based on the analysis of the unit volume displacement constraints, an optimization equation is proposed by adding an optimization factor to the original equation of the pitch curve of the sun wheel. It is seen that the addition of the new optimization factor eliminates the self-interlacing of the pitch curve of inner ring gear. This elimination increases the unit volume displacement of the motor.

Comparison of the Efficiency of Solar Collectors in Terms of the Working Medium—Review of Selected Technical Solutions

In Poland, the most commonly used solar fluid in heating installations with solar collectors are 35–50% water propylene glycol solutions or ethyl. These mixtures (with ennobling additives) effectively protect the solar installation against the effects of freezing of the working medium at low outside temperatures prevailing in winter. These solutions, compared to water, are characterized by higher viscosity and lower values of the specific heat in the range of typical working temperatures of the working fluid in the solar circuit, have a higher price per unit volume, and may cause poisoning due to accidental ingestion. It is possible in solar installations operating also in winter use of water only, without the addition of glycols, but then equipment is necessary the automatic control system controlling the installation with the protection function of anti-freeze. The aim of this study is to review selected examples of solar installations in which water was used as the solar fluid, proving the disadvantage of using glycol.

Improved Powder Equivalence Model for the Mix Design of Self-Compacting Concrete with Fly Ash and Limestone Powder

The use of fly ash (FA) limestone and powder (LP) in combination with cement in concrete has several practical, ecological, and economic advantages by reducing carbon dioxide emissions, reducing the excessive consumption of natural resources, and contributing to a cleaner production of self-compacting concrete (SCC). A mix design method for SCC based on paste rheological threshold theory can guide the SCC mix design by paste tests. This method can be visualized by the self-compacting paste zone (SCP zone), a plane area where all the mix points meet the paste threshold theory, and SCC zone, a plane area consisting of all the mix points satisfying the criteria of qualified SCC. In the case of cement SCC, the SCP zone coheres with the SCC zone. However, in the case of the addition of FA or LP with different granulometry and shape characteristics from cement, experimental results indicate that the SCP zone is separated from the SCC zone. This work quantitatively studied the influence of FA and LP on the movement of the SCP zone by introducing the improved powder equivalence model. The improved model was obtained by powder equivalence coefficients calculated through the mortar test results with or without FA or LP, instead of SCC tests in the former method. The equivalence coefficients by volume of FA and LP are 0.55 and 0.79, respectively, which means that 1.82 unit volume of FA or 1.27 unit volume of LP is equivalent to one unit volume of cement. The improved powder equivalence model was verified by the successful preparation of SCC incorporating FA or LP simply and effectively. The equivalent SCP zone cohered better with the SCC zone than the former SCP zone, which could guide the quick mix design of SCC without SCC premix tests.

Phase diagram senses orbitals and prompts a fundamental constant

Van der Waals’ discovery of that the volumes of molecules and their intermolecular attraction between them cause the peculiarities of the phase diagrams of gases and liquids1 gave the greatest impact on the progress of science and industry. Unfortunately, the phase charts of solids capable to advance scientific and technical progress remain uncomprehended mystery. Only the certain linear phase boundaries are understood by the struggle of magnetic field B against the thermal agitation2,3. Here we show that the intersection volume of internal atomic orbitals determines the form of phase boundary and, furthermore, energy per unit volume of the intersection is a new fundamental constant v = 8.941 eV/Å3. Together with the known struggle contribution2,3 to TC(B), we found a term proportional to the intersection volume of 3deg and 2p orbitals in the Sm0.55Sr0.45MnO3 manganite. Hysteresis of TC is described by the avalanche-like widening of the intersection volume due to reducing the Coulomb distortion with double-exchange ferromagnetism. The pressure-TC diagram4 of (Sm1-xNdx)0.55Sr0.45MnO3 (x=0, 0.2, 0.4, 0.5) is approximated with the same parameters as the TC(B) diagram of Sm0.55Sr0.45MnO3. Furthermore, the diamond’s melting point 4157oC calculated from the intersection volume of sp3-orbitals is in excellent agreement with the real 4000oC. Tips explaining the puzzling pressure-TN diagrams5-10 of NiS, Ni1-xS1-ySey, BaVS3, V2O3, RNiO3 and ferrites were given. Our discovery is the beginning of condensed-matter geometrodynamics and marks an era of studying phase diagrams to advance condensed-matter physics and tailor new materials with predicted properties necessary in sunrise industries. Moreover, internucleon, interquark and intergluon orbital intersections would be useful for understanding the properties of nuclei, nucleons and quarks.

Consistency of Pituitary Adenoma: Prediction by Pharmacokinetic Dynamic Contrast-Enhanced MRI and Comparison with Histologic Collagen Content

Prediction of tumor consistency is valuable for planning transsphenoidal surgery for pituitary adenoma. A prospective study was conducted involving 49 participants with pituitary adenoma to determine whether quantitative pharmacokinetic analysis of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is useful for predicting consistency of adenomas. Pharmacokinetic parameters in the adenomas including volume of extravascular extracellular space (EES) per unit volume of tissue (ve), blood plasma volume per unit volume of tissue (vp), volume transfer constant between blood plasma and EES (Ktrans), and rate constant between EES and blood plasma (kep) were obtained. The pharmacokinetic parameters and the histologic percentage of collagen content (PCC) were compared between soft and hard adenomas using Mann–Whitney U test. Pearson’s correlation coefficient was used to correlate pharmacokinetic parameters with PCC. Hard adenomas showed significantly higher PCC (44.08 ± 15.14% vs. 6.62 ± 3.47%, p < 0.01), ve (0.332 ± 0.124% vs. 0.221 ± 0.104%, p < 0.01), and Ktrans (0.775 ± 0.401/min vs. 0.601 ± 0.612/min, p = 0.02) than soft adenomas. Moreover, a significant positive correlation was found between ve and PCC (r = 0.601, p < 0.01). The ve derived using DCE-MRI may have predictive value for consistency of pituitary adenoma.