bluuebunny/crossref_metadata_2025_split huggingface dataset:
Underground and Out of Sight
Authors: Kosowatz John 
Published: March 2021

Abstract
Workers recently finished the last piece of tunnel for Kuala Lumpur’s second metro line, capping a program where autonomous tunneling machines have been operating remotely since 2016. Getting to that point took a poke by a seasoned tunneling director and TBM manager who found an unlikely duo of young, computer savvy, code-writing engineers who brought steering, advancement, excavation, and slurry operations under one operating system.
The Determination of the Expansion Forces in Piping by Model Test
Authors: Semar Harold W. 
Published: March 2021

Abstract
The paper describes apparatus for testing models of piping installations to determine the forces set up in the full-size installation due to expansion. The method consists in fixing one end of the model in a slide which can be moved a measured amount, and measuring the forces at the other end by means of a fixture which holds that end rigidly in place and permits measurement of six forces in three coordinate planes, which are the equivalent of forces in coordinate directions plus moments in coordinate planes. The slide of the movable end is placed so that its direction of motion coincides with the direction of the pipe expansion.
A complete example is given showing the steps in determining the end reactions of an inlet pipe for a steam turbine.
The Distribution of Load on the Threads of Screws
Authors: Goodier J. N. 
Published: March 2021

Abstract
The distribution of load on the threads of screws and the types of deformation affecting it have been investigated by means of extensometer measurements made on the outside of the nut. The types of deformation characteristic of concentrations of load on different parts of the thread were found by using a bolt carrying only a single turn of thread. At low loads the deformations of nuts with complete bolts closely resemble the effects of the artificial concentration of load on the base part of the thread, whereas there are marked contrasts with the effects of loads concentrated at the middle or at the free end. At higher loads a more uniform distribution is indicated. Similar conclusions follow from the application of an approximate method for deducing the distribution from the deformation measurements.
It is shown that the distribution is governed by (a) stretch and compression in bolt and nut, respectively, which are primarily responsible for concentration at the base; and (b) by bending of the thread, circumferential stretch (at the base), and contraction (near the free end) of the nut wall, which have comparable effects in reducing the concentration.
Stresses and Deflections of Three-Dimensional Pipe Bends
Authors: Poritsky H. , Snively H. D. 
Published: March 2021

Abstract
Many treatments of stresses of three-dimensional pipe bends have appeared in recent times. While the calculation of these stresses and deflections is perfectly straightforward, it is still very complicated. It is believed that the analogy to which attention is called in this paper should be of considerable assistance in simplifying these calculations by pointing out their similarity to familiar dynamical concepts involving products and moments of inertia and moments of momentum.
Measurement of Impact Strains by a Carbon-Strip Extensometer
Authors: Fanning R. , Bassett W. V. 
Published: March 2021

Abstract
This paper describes a method of experimentally ascertaining the actual stress-time curve in a mechanical part subjected to an impact blow. The apparatus consists of a resistance strain gage in conjunction with a high-speed recording oscillograph, the combination being sufficiently rapid in response to record strain variations occurring within a few microseconds. Consequently, the strains during impact are recorded with sufficient accuracy for detailed analysis.
Longitudinal strain waves in long bars striking end to end have been subjected to theoretical analysis and have served as a subject for testing of the apparatus. The theory is reviewed in this paper, and computed results based thereon are compared with experimental data. The agreement is shown to be satisfactory, the form being as predicted and the magnitude within a few per cent of the computed value.
The strain waves and reflections occurring in this simple case are surprisingly complex. An investigation of other impact problems by this method, such as the correlation of standard impact tests of materials, might well yield information of considerable value.
The Normal Modes of Vibrations of Beams Having Noncollinear Elastic and Mass Axes
Authors: Garland Clyne F. 
Published: March 2021

Abstract
This analysis deals with vibration characteristics of cantilever beams in which the longitudinal axis, passing through the mass centers of the elementary sections, is not collinear with the longitudinal axis about which the beam tends to twist under the influence of an applied torsional couple. Expressions are derived from which the natural frequencies and normal modes of vibration of such a beam can be determined. The Rayleigh-Ritz method is employed to determine the frequencies and amplitude ratios. Following the development of the general expressions, more specific equations are derived which express the natural frequencies and relative amplitudes of motion in each of two normal modes of vibration.
The theoretical relationships of the several physical properties of the beam to the natural frequencies of vibration are shown graphically. Finally a numerical example is presented for a particular beam, and the computed natural frequencies and normal modes are compared with those determined experimentally.
Strengthening Cylindrical Tanks of Variable Thickness Under External Pressure by Circular Stiffening Rings
Authors: Biezeno C. B. , Koch J. J. 
Published: March 2021

Abstract
In a previous paper the authors discussed the buckling of a cylindrical tank of variable thickness under external pressure, and they developed a method by which the factor of safety against buckling was derived in numerical terms.
This present paper deals with the strengthening of a tank whose factor of safety is insufficient. Obviously, great help may be expected from one or two stiffening circular rings, adjusted in the upper part of the tank, where the thickness of the shell is small. The authors show how to calculate such rings.
On the Zeros of an Undamped Three Degrees-of-Freedom Flexible System
Authors: Rath Siddharth , Cui Leqing , Awtar Shorya 
Published: March 2021

Abstract
This paper presents an investigation of zeros in the SISO dynamics of an undamped three degrees-of-freedom (3DOF) linear time invariant (LTI) flexible system. Of particular interest are non-minimum phase zeros, which severely impact closed-loop performance. This study uses modal decomposition and zero loci to reveal all types of zeros—marginal minimum phase (MMP), real minimum phase (RMP), real non-minimum phase (RNMP), complex minimum phase (CMP), and complex non-minimum phase (CNMP)—that can exist in the system under various parametric conditions. It is shown that if CNMP zeros occur in the dynamics of an undamped LTI flexible system, they will always occur in a quartet of CMP-CNMP zeros. Consequently, the simplest undamped LTI flexible system that can exhibit CNMP zeros in its dynamics is a 3DOF system. Motivated by practical examples of flexible systems that exhibit CNMP zeros, the undamped 3DOF system considered in this paper comprised one rigid-body mode and two flexible modes. For this system, the following conclusions are mathematically established: (1) This system exhibits all possible types of zeros, (2) The precise conditions on modal frequencies and modal residues associated with every possible zero provide a mathematical formulation of the necessary and sufficient conditions for the existence of each type of zero, and (3) Alternating signs of modal residues is a necessary condition for the presence of CNMP zeros in the dynamics of this system. Conversely, avoiding alternating signs of modal residues is a sufficient condition to guarantee the absence of CNMP zeros in this system.
Design of a Tip Appendage for the Control of Tip Leakage Vortices in Axial Flow Fans
Authors: Meyer Thomas O. , van der Spuy Sybrand J. , Meyer Christiaan J. , Corsini Alessandro 
Published: March 2021

Abstract
This article reports on numerical investigations of passive control techniques used for the performance enhancement of a large diameter axial flow cooling fan through modification of the blade tip geometry. Using open-source software, a novel meshing strategy is developed to carry out both steady and unsteady numerical computations of a periodic section of an axial flow fan. Analyzing the flow near the blade tip with a reduction in tip clearance, two predominant flow phenomena are identified. These two flow phenomena are further investigated with the aim of controlling them through implementation of a tip appendage design. Both introduced end-plate designs indicate effective control of each relevant flow phenomena. The constant thickness (CT) end-plate design is found to increase all fan performance characteristics at lower than design point (DP) flowrates, while increasing the fan’s peak efficiency plateau toward the rotor stall margin. However, none of the CT end-plate designs are able to improve the fan’s performance characteristics at its DP. The introduction of a novel trailing-edge (TE) end-plate design is found to increase all fan performance characteristics across the entire evaluated stable operating range, with an indicated increase of 37.3 percent in total-to-static pressure rise and a 2.9 percentage point increase in total-to-static efficiency at the fan’s DP flowrate. The aerodynamic performance results attest to the associated benefits of the investigated passive control techniques.
Electroacupuncture for pain relief in labour inhibits spinal p38 MAPK-mediated prostaglandin E2 release and uterine prostaglandin E2 receptor expression in rats
Authors: Jiang Gui-Xiu , Jiang Qiu-Yan , Mo Hai-Xia , Li Li , Wang Meng-Ying 
Published: March 2021

Background: p38 mitogen-activated protein kinase (p38 MAPK) activation involves the release of prostaglandin E2 (PGE2) and hyperalgesia. We have previously reported that electroacupuncture (EA) relieves labour pain, but the potential mechanisms remain unclear. Objective: To observe the effects of EA on labour pain intensity, serum PGE2 levels and the p38 MAPK signalling pathway in rats during labour. Methods: Female rats copulated with male rats to induce pregnancy, and then received castor oil to trigger labour. During labour, rats remained untreated (Control group, n=30) or were treated with remifentanil (n=30) or EA at Jiaji (n=30) or SP6+LI4 (n=30), respectively. The warm water tail-flick test was used to assess labour pain. Serum PGE2 levels were measured by ELISA. Protein expression of prostaglandin E2 receptor (PGER2), p38 MAPK and phospholipase A2 (PLA2) were analysed by Western blotting, and mRNA levels were measured by real-time PCR. Results: EA treatment at Jiaji or SP6+LI4 significantly relieved labour pain, decreased serum PGE2 levels and inhibited protein and gene expression of PGER2 in the myometrium. Moreover, EA reduced protein expression of PLA2 and p38 MAPK, and inhibited phosphorylation of p38 MAPK in the lumbar spinal cord but not in the cerebral grey matter. Additionally, EA markedly decreased mRNA levels of p38 MAPK in the lumbar spinal cord and significantly reduced PLA2-IV mRNA levels in both the lumbar spinal cord and cerebral grey matter. Conclusions: This study indicates that EA relieves labour pain through, at least in part, inhibition of spinal p38 MAPK-mediated PGE2 release and uterine PGER2 expression in rats.
Airborne occupational exposures and the risk of developing respiratory symptoms and airway obstruction in the Lifelines Cohort Study
Authors: Faruque Md Omar , Boezen H Marike , Kromhout Hans , Vermeulen Roel , Bültmann Ute , Vonk Judith M 
Published: March 2021

ObjectivesTo date, only a few studies have investigated the associations between occupational exposures and respiratory outcomes longitudinally in the general population. We investigated the associations between occupational exposures and the development of respiratory symptoms and airway obstruction in the Lifelines Cohort Study.MethodsWe included 35 739 occupationally active subjects with data on chronic cough, chronic phlegm, chronic bronchitis or airway obstruction at baseline and approximately 4.5 years follow-up. Exposures to biological dust, mineral dust, gases/fumes, pesticides, solvents and metals in the current job at baseline were estimated with the ALOHA+job-exposure matrix (JEM). Airway obstruction was defined as FEV1/FVC below the lower limit of normal. Logistic regression analysis adjusted for baseline covariates was used to investigate the associations.ResultsAt follow-up, 1888 (6.0%), 1495 (4.7%), 710 (2.5%) and 508 (4.5%) subjects had developed chronic cough, chronic phlegm, chronic bronchitis and airway obstruction, respectively. High exposure to biological dust was associated with a higher odds to develop chronic cough and chronic bronchitis. High exposure to pesticides was associated with a higher odds for the development of all respiratory symptoms and airway obstruction. In the multiple exposures analyses, only the association between pesticides exposure and respiratory symptoms remained.ConclusionsSubjects exposed to high pesticides had a higher odds to develop respiratory symptoms on average 4.5 years later. Control measures should be taken to reduce pesticides exposure among the working population to prevent respiratory symptoms and airway obstruction.
A comprehensive economic assessment of the health effects of tobacco use and implications for tobacco control in Bangladesh
Authors: Nargis Nigar , Faruque Golam Mohiuddin , Ahmed Maruf , Huq Iftekharul , Parven Rehana , Wadood Syed Naimul , Hussain AKM Ghulam , Drope Jeffrey 
Published: March 2021

BackgroundDespite modest progress in reducing tobacco use, tobacco remains one of the major risk factors for non-communicable diseases in Bangladesh.MethodsUsing disease-specific, prevalence-based, cost-of-illness approach, this research estimated the economic costs of tobacco use and exposure to secondhand smoke based on data collected from a nationally representative survey of 10 119 households in 2018.ResultsThe study estimated that 1.5 million adults were suffering from tobacco-attributable diseases and 61 000 children were suffering from diseases due to exposure to secondhand smoke in Bangladesh in 2018. Tobacco use caused 125 718 deaths in that year, accounting for 13.5% of all-cause deaths. The total economic cost was 305.6 billion Bangladeshi taka (BDT) (equivalent to 1.4% of gross domestic product or US$3.61 billion), including direct costs (private and public health expenditures) of BDT83.9 billion and indirect costs (productivity loss due to morbidity and premature mortality) of BDT221.7 billion. The total economic cost of tobacco more than doubled since 2004.ConclusionTobacco use imposes a significant and increasing disease and financial burden on society. The enormous tobacco-attributable healthcare costs and productivity loss underscore the need to strengthen the implementation of tobacco control policies to curb the epidemic.
Predictive Accuracy of a Polygenic Risk Score for Postoperative Atrial Fibrillation After Cardiac Surgery
Authors: Kertai Miklos D. , Mosley Jonathan D. , He Jing , Ramakrishnan Abinaya , Abdelmalak Mark J. , Hong Yurim , Shoemaker M. Benjamin , Roden Dan M. , Bastarache Lisa 
Published: March 2021

Background:
Postoperative atrial fibrillation (PoAF) remains a significant risk factor for increased morbidity and mortality after cardiac surgery. The ability to accurately identify patients at risk through clinical risk factors is limited. There is growing evidence that polygenic risk contributes significantly to PoAF and incorporating measures of genetic risk could enhance prediction.

Methods:
A retrospective cohort study of 1047 patients of White European ancestry who underwent either coronary artery bypass grafting or valve surgery at a tertiary academic center and were free from a history or persistent preoperative atrial fibrillation. The primary outcome was defined as PoAF based on postoperative ECG reports, medical record documentation, and changes in medication. The exposure was a polygenic risk score (PRS) comprising 2746 single-nucleotide polymorphisms previously associated with atrial fibrillation risk. The prediction of PoAF risk was assessed using measures of model discrimination, calibration, and net reclassification improvement.

Results:

A total of 259 patients (24.7%) developed PoAF. The PRS was significantly associated with a higher risk for PoAF (odds ratio, 1.63 per SD increase in PRS [95% CI, 1.41–1.90]). Addition of PRS to patient- and procedure-related predictors of PoAF significantly increased the C statistic from 0.742 to 0.782 (change in C statistic, 0.040 [95% CI, 0.021–0.060]) while maintaining good calibration. The addition of the PRS to patient- and procedure-related predictors of PoAF improved model fit (likelihood ratio test,
P
=2.8×10
−15
) and significantly improved measures of reclassification (net reclassification improvement, 0.158 [95% CI, 0.066–0.274]).

Conclusions:
The PRS for PoAF was associated with improved discrimination, calibration, and risk reclassification compared with conventional clinical predictors suggesting that a PoAF PRS may enhance risk prediction of PoAF in patients undergoing coronary artery bypass grafting or valve surgery.
Jesuits and Conversos as a “Tragic Couple”: Introductory Remarks
Authors: Stuczynski Claude B. 
Published: March 2021

Abstract
This article introduces the phenomenon of Jesuit-converso interactions, mostly in the early modern Iberian world. It summarizes the shifting attitudes of the Society of Jesus vis-à-vis New Christians of Jewish origin as actual or potential Jesuits and maps the multifaceted and variegated interplay between Jesuit priests and converso laymen, understood as a “tragic couple” relationship. This brief survey emphasizes the historiographical contribution of the last generations of Jesuit scholars, and of the five articles included in this special issue of the Journal of Jesuit Studies, to disclose a more overt “historical memory” of the Society of Jesus.
4. Jordan
Authors: Tweissi Basim 
Published: March 2021

This chapter will shed light on the main features of the Jordanian media system and how it relates to the political, economic, and legal systems. It focuses on the efforts to develop a sustainable media industry under difficult circumstances. For many decades, Jordan navigated the turbulent waters of the Middle East, the scene of devastating regional wars, civil wars, uprisings, and political instability, all of which undermined the efforts for political reform and the development of a healthy, robust media.
The pathobiology of thrombosis, microvascular disease, and hemorrhage in the myeloproliferative neoplasms
Authors: Hasselbalch Hans Carl , Elvers Margitta , Schafer Andrew I. 
Published: March 2021

Abstract
Thrombotic, vascular, and bleeding complications are the most common causes of morbidity and mortality in the Philadelphia chromosome–negative myeloproliferative neoplasms (MPNs). In these disorders, circulating red cells, leukocytes, and platelets, as well as some vascular endothelial cells, each have abnormalities that are cell-intrinsic to the MPN driver mutations they harbor (eg, JAK2 V617F). When these cells are activated in the MPNs, their interactions with each other create a highly proadhesive and prothrombotic milieu in the circulation that predisposes patients with MPN to venous, arterial, and microvascular thrombosis and occlusive disease. Bleeding problems in the MPNs are caused by the MPN blood cell-initiated development of acquired von Willebrand disease. The inflammatory state created by MPN stem cells in their microenvironment extends systemically to amplify the clinical thrombotic tendency and, at the same time, preferentially promote further MPN stem cell clonal expansion, thereby generating a vicious cycle that favors a prothrombotic state in these diseases.
Annual incidence and severity of acute episodes in hereditary thrombotic thrombocytopenic purpura
Authors: Tarasco Erika , Bütikofer Lukas , Friedman Kenneth D. , George James N. , Hrachovinova Ingrid , Knöbl Paul N. , Matsumoto Masanori , von Krogh Anne Sophie , Aebi-Huber Isabella , Cermakova Zuzana , Górska-Kosicka Magdalena , Jalowiec Katarzyna A. , Largiadèr Carlo R. , Prohászka Zoltán , Sinkovits György , Windyga Jerzy , Lämmle Bernhard , Kremer Hovinga Johanna A. 
Published: March 2021

Abstract
Hereditary thrombotic thrombocytopenic purpura (hTTP) is a rare thrombotic microangiopathy characterized by severe congenital ADAMTS13 deficiency and recurring acute episodes causing morbidity and premature death. Information on the annual incidence and severity of acute episodes in patients with hTTP is largely lacking. This study reports prospective data on 87 patients from the Hereditary TTP Registry (clinicaltrials.gov #NCT01257269) for survival, frequency, and severity of acute episodes from enrollment until December 2019. The 87 patients, followed up for a median of 4.2 years (range, 0.01-15 years), had a median age at overt disease onset and at clinical diagnosis of 4.6 years and 18 years (range, 0.0-70 years for both), respectively. Forty-three patients received regular plasma prophylaxis, whereas 22 did not, and treatment changed over time or was unknown in the remaining 22. Forty-three patients experienced 131 acute episodes, of which 91 (69%) occurred in patients receiving regular prophylaxis. This resulted in an annual incidence of acute episodes of 0.36 (95% confidence interval [CI], 0.29-0.44) with regular plasma treatment and of 0.41 (95% CI, 0.30-0.56) without regular plasma treatment. More than one-third of acute episodes (n = 51) were documented in children &lt;10 years of age at enrollment and were often triggered by infections. Their annual incidence of acute episodes was significantly higher than in patients aged &gt;40 years (1.18 [95% CI, 0.88-1.55] vs 0.14 [95% CI, 0.08-0.23]). The prophylactic plasma infusion regimens used were insufficient to prevent acute episodes in many patients. Such regimens are burdensome, and caregivers, patients, and their guardians are reluctant to start regular plasma infusions, from which children particularly would benefit.