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Salomón Hakim (1922–2011) was a Colombian neurosurgeon and brain scientist This biography examines the social and cultural background through which he emerged as an inquisitive and multi-dimensional surgeon-scientist, and his lifelong contributions to the specialty of neurosurgery. With empirical knowledge in applied medical physics, electronics, electricity and chemistry, he understood the paradoxical phenomenon of symptomatic hydrocephalus with normal cerebrospinal fluid pressure. This ultimately led Hakim to describe in exquisite detail the physics of the cranial cavity and brain hydrodynamics. His name is intertwined with the identification of the entity of a syndrome which had not previously been addressed in the medical literature: Normal Pressure Hydrocephalus (Hakim's syndrome). Additionally, he designed and built various models of valved shunting devices to treat the condition (eg the Hakim programmable valve). Through his selflessness and cogent work, Hakim left a legacy and intellectual heritage that has allowed many colleagues worldwide to save thousands of lives who would be otherwise condemned to oblivion. [ABSTRACT FROM AUTHOR]

This study aims to determine the use of experimental videos of hydraulic concepts (Pascal's law) of everyday products in the learning process for 10 students with special needs and 10 vocational school students. We used both quantitative and qualitative methods. Experimental videos were used in the learning process for supporting demonstration activities of hydraulic concepts using tools and materials from everyday products. Pretest and posttest were carried out to determine the level of understanding of students. The results showed that the level of understanding of students had increased after using experimental videos in the learning process. The use of experimental video learning media that is tailored to the needs of the students makes it easier for students to understand the material being taught. In addition, the use of tools and materials for everyday products makes it easier for students with special needs to understand the material being taught. This is because they find it easier to understand something concrete, simple, and repetitive or they often encounter it in their daily activities. The use of experimental videos can be used as an alternative learning media for students with special needs and students in general in vocational school during the pandemic. [ABSTRACT FROM AUTHOR]

Through an in-depth analysis of the notes that Leibniz made while reading Pascal's manuscript treatise on conic sections, we aim to show the real extension of what he called "hexagrammum mysticum", and to highlight the main results he achieved in this field, as well as proposing plausible proofs of them according to the methods he seems to have developed. [ABSTRACT FROM AUTHOR]

An amniotic sheet is a septation in the amniotic cavity with a perforation that allows amniotic fluid to pass through. Although the incidence of abnormal placental implantation is higher in such cases, the management recommendations remain unclear. We report a case of an amniotic sheet with a hammock-like placenta located in the center of the uterine cavity. A 25-year-old woman with a history of two dilation and curettage procedures was found to have an amniotic cavity separated by a septum that contained part of the placenta. At gestational Week 32, magnetic resonance images revealed that the placenta was attached from the anterior to posterior uterine walls and resembled a hammock hanging in the center of the uterus. Subsequently, continuous intravenous administration of ritodrine hydrochloride and magnesium sulfate were given. The pregnancy was extended to Week 36. Elective cesarean section was performed, and a 3212-g female infant was delivered. Thus, owing to the risk of umbilical cord complications and placental injury secondary to premature rupture of membranes, aggressive and careful perinatal management is required in such cases.

In this paper a direct generalisation of the recombining binomial tree model by Cox et al. (J Financ Econ 7:229-263, 1979) based on the Pascal’s simplex is constructed. This discrete model can be used to approximate the prices of derivatives on multiple assets in a Black-Scholes market environment. The generalisation keeps most aspects of the binomial model intact, of which the following are the most important: The direct link to the Pascal’s simplex (which specialises to Pascal’s triangle in the binomial case); the matching of moments of the (log-transformed) process; convergence to the correct option prices both for European and American options, when the time step length goes to zero and the completeness of the model, at least for sufficiently small time step. The goal of this paper is to present basic theoretical aspects of this approach. However, we also illustrate the approach by a number of example calculations. Further possible developments of this approach are discussed in a final section. [ABSTRACT FROM AUTHOR]

A new smart U-shaped triboelectric nanogenerator (TENG) was reported basing on solid-liquid contact triboelectrification and the Pascal's law, in which the complicated mechanical motions can be transmitted into liquid pressure and electricity signal. The U-shaped TENG driven by inertial force and air flow is designed as an energy harvesting device to collect the mechanical energy with a stable peak output voltage and current of about 20 V and 400 nA, respectively. The relationship between the output performance and the water sliding conditions is investigated in detail with a stable peak output performance at the point of resonance. The U-shaped TENG can also be working as smart multifunctional sensors to detect the displacement, pressure, torsion, and so on. As a self-powered displacement sensor, the U-shaped TENG shows a high sensitivity of 0.91 V mm −1 and 8.50 nA mm −1 . As a pressure sensor, it also exhibits a high sensitivity of 4.41 V kPa −1 and 72.94 nA kPa −1 , respectively. This work expands the practical applications of the solid-liquid triboelectrification based TENGs for energy harvesting and smart sensors in wide fields with advantages of simple fabrication, low cost, portable and self-powered properties. [ABSTRACT FROM AUTHOR]

Physical examination of any swelling is the first step in making a diagnosis. Many a times we see a patient with a spherical swelling, which is usually a cyst. The interpretation of physical signs should be based on sound principles of physics. In the present paper, we explain physical characteristics of a swelling (cyst) using principles of fluid mechanics. [ABSTRACT FROM AUTHOR]

Recently, surgical manipulators have been widely used to support human operations, such as surgical operations. These manipulator systems are suitable for careful work, but they have a few problems. One problem is that the manipulators are not equipped with haptic sensing functions. When a manipulator does not employ haptic sensing functions, an operator can only conduct an operation using visual feedback. Therefore, to substitute for visual detection, it is necessary for the operator to use advanced techniques to determine physical contact during an operation. We have developed a new mechanism to solve this problem. A hydraulically driven joint is constructed in a spherical bearing and bellows tubes that enables a haptic sense display for the operator. This system can measure the small forces acting on the tips of the manipulator using Pascal’s principle. A model of the system is derived from the relationship between the internal pressure of the bellows tube and the refraction angles of the joint. In this study, we quantitatively investigated the relationship between the internal pressure of the bellows tubes and the refraction angles of the joint. To estimate the refraction angle, we measured the quantity of water that was provided from syringes. It was confirmed that the developed system allowed for an estimation of both the strength and direction of the external force applied to the manipulator by measuring the bellows tubes’ internal pressure. This report describes the prototype joint. [ABSTRACT FROM AUTHOR]

Given a multi-variable polynomial, there is an associated divided symmetrization (in particular turning it into a symmetric function). Postinkov has found the volume of a permutohedron as a divided symmetrization (DS) of the power of a certain linear form. The main task in this paper is to exhibit and prove closed form DS-formulas for a variety of polynomials and some rational functions. We hope the results to be valuable and available to research practitioners in these areas. In addition, the methods of proof utilized here are simple and amenable to many more analogous computations. [ABSTRACT FROM AUTHOR]

The paper extends a classical result on the convergence of the Krawtchouk polynomials to the Hermite polynomials. We provide a uniform asymptotic expansion in terms of Hermite polynomials and obtain explicit expressions for a few first terms of this expansion. The research is motivated by the study of ergodic sums of the Pascal adic transformation. Bibliography: 10 titles. [ABSTRACT FROM AUTHOR]

We give some alternative forms of the generating functions for the Bernstein basis functions. Using these forms,we derive a collection of functional equations for the generating functions. By applying these equations, we prove some identities for the Bernstein basis functions. Integrating these identities, we derive a variety of identities and formulas, some old and some new, for combinatorial sums involving binomial coefficients, Pascal's rule, Vandermonde's type of convolution, the Bernoulli polynomials, and the Catalan numbers. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The article discusses how misconceptions about density among high school students bring problems to them while learning about Pascal's principle in physics. It highlights a misconception among students that heavy objects sink and light objects float in water, while physics says mass does not affect floating, explains that relationship between volume and sinkability is indirect while the relationship between mass and sinkability is direct, and mentions students' understanding about density.

According to conventionalist accounts of personal identity, persons are constituted in part by practices and attitudes of certain sorts of care. In this paper, we concentrate on the most well-developed and defended version of conventionalism currently on offer (namely, that proposed by David Braddon- Mitchell, Caroline West, and Kristie Miller) and discuss how the conventionalist appears forced either (1) to accept arbitrariness concerning from which perspective to judge one's survival or (2) to maintain egalitarianism at the cost of making 'transfiguring' decisions such as Pascal's Wager rationally intractable. We consider three ways the egalitarian conventionalist could make these choices tractable and show that each one comes at significant cost to the view. We end the paper by considering whether accepting arbitrariness would be a better move for the conventionalist and conclude that, even here, she runs the risk of transfiguring choices being rationally intractable. [ABSTRACT FROM AUTHOR]

A novel, efficient, economical oil collection device, which recovers oils from surface waters using physical principles has been demonstrated. This method has never been used in oil skimmers. The device contains a water-filled vessel open at one end that is positioned above the spilled oil so that the oil entrance opening is leveled with the oil layer on the water surface. The oil moves upward into the vessel displacing the water due to the lower density of the oil. The device has no moving parts. Torricelli's discovery and Pascal's law govern containment of the liquid in the vessel above the water level, while Archimedes' buoyancy force moves oil in the vessel. A collection of thick and thin oil layers on calm water has been shown. This device is very durable, environmentally friendly, recovers pure oil, emits no noise, no pollution, and capable of producing a broad economic impact in the oil clean-up industry by protecting health, life, and the environment. [ABSTRACT FROM AUTHOR]

Gay-Lussac's 1801 experiments establishing the law of volumes for gases are brilliantly simple, and he described them with a level of detail that was new to physics writing. But he did not present his actual measurements or tell us how he analyzed them to conclude that between 0 to 100 °C, a volume of any gas will expand by about 37.5%. We review his experiments and conclude that he measured initial and final volumes at slightly different pressures. By using the gas laws and his apparatus diagrams, we corrected his data so that they correspond to constant pressure. His corrected results give ΔV/ V=36.6%, the currently accepted value for nearly ideal gases. Aside from their intrinsic interest, our analyses can provide students intriguing applications of the gas laws and Pascal's law and motivate them to consider Pascal's paradox. We also note the influence of ballooning and of the French Revolution on Gay-Lussac. [ABSTRACT FROM AUTHOR]

Abstract: In response to familiar problems with work on universals, it is proposed that there are genuine and exceptionless linguistic universals, but that they are derived not from data about the properties of individual languages but rather from more basic facts about non-linguistic mechanisms involved in language production, comprehension, and acquisition. The proposal is illustrated with the help of two phenomena, one involving the distribution of voiced stops in phonology and the other pertaining to constraints on filler-gap dependencies in syntax. [ABSTRACT FROM AUTHOR]

Venous obstruction is a major complication of transvenous pacemaker placement. Despite the increasing use of pacemakers and implantable cardiac defibrillators, a lack of understanding remains with regard to risk factors for the development of device-associated venous obstruction. We hypothesize that computational fluid dynamics simulations can reveal prothrombogenic locations and define thrombosis risk based on patient-specific anatomies. Using anatomic data derived from computed tomography, computer models of the superior vena cava, subclavian, innominate, and internal jugular veins were constructed for three adult patients with transvenous pacemakers. These models were used to perform patient-specific simulations examining blood flow velocity, wall shear stress, and blood pressure, both with and without the presence of the pacing leads. To better quantify stasis, mean exposure time fields were computed from the venous blood flow data. In comparing simulations with leads to those without, evident increases in stasis at locations between the leads and along the surface of the vessels closest to the leads were found. These locations correspond to regions at known risk for thrombosis. This work presents a novel application of computational methods to study blood flow changes induced by pacemaker leads and possible complications such as venous occlusion and thrombosis. This methodology may add to our understanding of the development of lead-induced thrombosis and occlusion in the clinical arena, and enable the development of new strategies to avoid such complications. [ABSTRACT FROM AUTHOR]

Traditional water displacement volumetry, based on Archimedes' principle of buoyancy, is considered the gold-standard for limb volume measurement. However, the routine use of this technique is associated with a series of disadvantages: the method is cumbersome to the patient, messy and unhygienic, and it takes a great amount of the examiner's time. This article presents the prototype of a new piece of equipment designed according to Pascal's principle of communicating vases for the direct evaluation of hand volume. [ABSTRACT FROM AUTHOR]

Polynomial recursion is easier to understand than linear homogeneous equations. Second and third degree polynomial recursion equations are developed from finite difference equations. A general recursion formula for nth order polynomials is developed from finite difference equations and given in terms of Pascal's triangle coefficients. Using Excel, several examples of polynomial equations and the resultant recursion formula are given. [ABSTRACT FROM AUTHOR]

Pressure balances are used as primary level reference measurement instruments. These kinds of instruments have wide pressure ranges up to 1 GPa. In such instruments, the uncertainty of the reference pressure value can be lowered to around 6-7 ppms. In pressure balance systems which consist of a prison-cylinder unit, mass set and base, reference pressure is obtained by exerting vertical force from the mass set onto the piston with a well-known effective area. There are many parameters to be considered such as mass, the material of the piston-cylinder unit, the thermal expansion coefficient, temperature, air bouyancy effect, the pressure distortion coefficient, local gravity acceleration, etc. during the calculation of reference pressure value. In this paper, we present and explain the parameters that need to be taken into account in order to accurately calculate the reference pressure value for primary level pressure balances. [ABSTRACT FROM AUTHOR]

The dominance of natural hazards in our environment is very high. Only when natural events occur does one realize their power and consequences. The risk potential of natural hazards and their possible consequences have prompted scientific studies of torrent events and barrier structures. This paper presents a method that allows the assessment of uncertain stress forces and resisting elements. The method is based on a probabilistic approach and includes uncertain parameters regarding acting and resistance in a risk analysis. This way of modelling also enables time changes of the barrier resistance to be taken into account. Basic information on the types of torrential barriers used is given and traditional assessment methods and loads are described. [ABSTRACT FROM AUTHOR]

As an alternative in the energetic utilization of energy of periodical nature, it becomes a study of generators to use directly the movements translational, without the need to make conversions to rotational energy. The operation of the generator is based on the law of induction of Faraday, in the same way that makes all the electrical machines. This document is focused on the use of the waves as part of the tidal power, it is therefore requires the implementation of some concepts of the hydrostatic and statistical data of the waves for a supposed place of mounting the machine. With the previous information is developed a program in Matlab® to provide the necessary data for the subsequent design of the machine. [ABSTRACT FROM AUTHOR]

The article explains the use of tabulated diamagnetic susceptibilities, or empirical Pascal's constants, to correct for the fundamental or underlying diamagnetism of a paramagnetic compound. According to the authors, diamagnetism is a property of all atoms in molecules. They add that a compound having unpaired electrons, but with an abundance of other paired electrons, like a metalloprotein, may display diamagnetism at room temperature in a bulk measurement. The authors also discuss the origin of the diamagnetic correction factors, organized tables of constants, a simple method for estimating the correct order of magnitude for the diamagnetic correction for any given compound and a working example for the magnetic susceptibility of copper acetate.

Abstract  A general description is given of the mathematical modelling of physical properties of liquid mixtures, with an emphasis on the early progress in mathematical representation of mixtures’ thermodynamics. The core issue is employing long polynomials to represent mixing data accurately, without having to optimise a large number of independent parameters. This is for instance done by deriving the long polynomials from explicit (analytical) models with few independent parameters. It is shown that this field evolved not by gradual changes in model complexity and accuracy, but rather in bursts, followed by pausing for several years or decades whenever researchers hit computational or conceptual limitations. One such limitation that still exists is the Taylor expansion of the above mentioned analytical models. This article presents a novel use of Pascal’s triangle that turns this computationally “hard” problem into a trivial iterative procedure, suitable for standard office spreadsheets. The process of transforming this hard problem into a soft problem may be described as deciphering. The present author conjectures that for every parametric function for which a polynomial expansion can be made, there is a corresponding coefficient pattern involving Pascal’s triangle and/or other binomial sequences and matrices. [ABSTRACT FROM AUTHOR]

An analytical Pascal matrix transform is proposed for conversions of transfer functions between s- and z-domains. The transform is formulated uniformly for first-order a-to-z transforms, and its Pascal matrix is derived logically and analytically. The inverse transform is then formed in terms of its forward transform matrices without computing the matrix in verses. Computation examples show that the presented Pascal matrix transform works simply and efficiently. [ABSTRACT FROM AUTHOR]

Let P=[pi,j]i,j⩾0 be an infinite matrix whose entries satisfy pi,j=λpi-1,j+μpi,j-1+νpi-1,j-1 for i,j⩾1, and whose first column respectively row satisfy linear recurrences with constant coefficients of orders ρ respectively σ. Then we show that its principal minors dn satisfy dn=∑j=1δcjωjndn-j where cj are constants, ω=λμ+ν, and δ=ρ+σ-2ρ-1. This implies a recent conjecture of Bacher [J. Théor. Nombres Bordeaux 14 (2002) 19–41]. The tools that we use are a formula for the generating function of a matrix product, and the fact that the principal minors of every band-diagonal matrix satisfy a nontrivial linear recurrence. [Copyright &y& Elsevier]

The chief purpose of this activity is to strengthen students' understanding of concepts of floatation such as surface area and pressure {weight per unit area) via snowshoes. Students brainstorm, make predictions, perform calculations, and practice communication skills through interviewing elders and experts. This activity lets students see the marvelous relationship between the structural features of animals and their environment. They also get a better understanding of how humans have become better adapted to their environment by copying animals like the snowshoe hare. Students build their own snowshoes. and teachers have the opportunity to introduce American-Indian culture or integrate other social studies themes. [ABSTRACT FROM AUTHOR]

Shares some of the aspects of Pascal matrix that show how it is related to other matrices. Matrix creation and its creatures; Details on vector function; Relationship between the matrices P and S.

The purpose of this correspondence is to present an approach for verifying that explicitly stated integrity constraints are not violated by certain transactions. We utilize a relational model wherein constraints are given in a language based on the first-order predicate calculus. Transactions are written in terms of a Pascal-like host language with embedded first-order predicate calculus capabilities allowing queries and updates. The technique for proving consistency of the transactions is based upon the Hoare axiomatic approach. We illustrate the method by means of an explicit example of a database updated by four types of transaction. A generalized transaction consistency verifier embodying this approach would considerably enhance transaction programming in a relational database management system. [ABSTRACT FROM AUTHOR]

The article focuses on the Cartesian diver experiment in science. The experiment involves two bottles and two small plastic vials wherein the bottle will be squeezed and one of the vials will sink to the bottom of the bottle. The application of the Archimedes Principle and the Pascal's principle to the experiment is discussed. Steps to making one's own Cartesian Diver are provided.