bluuebunny/crossref_metadata_2025_split huggingface dataset:
From Precollege to Career: Barriers Facing Historically Marginalized Students and Evidence‐Based Solutions
Authors: Thiem Kelsey C. , Dasgupta Nilanjana 
Published: January 2022

AbstractAlthough the United States population is growing increasingly diverse, the diversity within higher education is not keeping pace. Contributing to the underrepresentation of students from historically marginalized groups are a variety of interconnected systemic barriers that prevent students from entering college, from thriving while there, and from persisting through to graduation. Here, we use the stereotype inoculation model as a guiding framework not only to identify these barriers and their psychological effects on students but also to highlight evidence‐based solutions that colleges and universities can implement to lower these barriers. As a function of our chosen model, we focus on features of educational environments that signal a lack of psychological fit among students from historically marginalized groups. Furthermore, we highlight interventions that can be implemented at the institutional level to change the educational environment and make higher education settings more inclusive and equitable.
Impact of COVID‐19 in hematopoietic stem cell transplant recipients: A systematic review and meta‐analysis
Authors: Shahzad Moazzam , Chaudhary Sibgha Gull , Zafar Muhammad U. , Hassan Maha A. , Hussain Ali , Ali Fatima , Anwar Iqra , Ahmed Mamoon , Ahmed Nausheen , Khurana Sharad , Rauf Muhammad A. , Anwar Faiz , Hematti Peiman , Callander Natalie S. , Abhyankar Sunil H. , McGuirk Joseph P. , Mushtaq Muhammad Umair 
Published: January 2022

AbstractBackgroundHematopoietic stem cell transplant (HSCT) recipients are at increased risk of mortality and morbidity with coronavirus disease 2019 (COVID‐19) due to severe immune dysfunction.MethodsA literature search was performed on PubMed, Cochrane, and Clinical trials.gov from the date of inception to 12/08/2021. We identified 19 original studies reporting data on COVID‐19 in HSCT recipients after screening 292 articles. Data were extracted following preferred reporting items for systematic reviews and meta‐analysis guidelines. Quality evaluation was done using the National Institutes of Health (NIH) quality assessment tool. Inter‐study variance was calculated using Der Simonian–Laird Estimator. Pooled analysis was conducted using MetaXL. A random‐effects model was used to estimate the proportions with 95% confidence intervals (CI).ResultsOf 6711 patients in 19 studies, 2031 HSCT patients with severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection were analyzed. The median age of patients was 56.9 (range 1–81.6) years, and 63% patients were men according to 14 studies. The median time from transplant to SARS‐CoV‐2 infection for autologous (auto) and allogeneic (allo) HSCT patients was 23.2 (0.33–350.5) months and 16.4 (0.2–292.7) months, respectively. The median follow‐up time after COVID‐19 diagnosis was 28 (0–262) days. The COVID‐19 mortality rate was 19% (95% CI 0.15–0.24, I2 = 76%, n = 373/2031). The pooled mortality rate was 17% (95% CI 0.12–0.24, I2 = 78%, n = 147/904) in auto‐HSCT patients and 21% (95% CI 0.16–0.25, I2 = 60%, n = 231/1103) in allo‐HSCT patients.ConclusionsHSCT recipients have a high risk of mortality and clinical complications due to COVID‐19. There is a need for ongoing vigilance, masks, and social distancing, vaccination, and aggressive management of SARS‐CoV‐2 infection in HSCT recipients.
Evaluation of Adhesive Interface Properties in Honeycomb Sandwich Structure Using Guided Waves
Authors: Negi Parambeer Singh , Koodalil Dileep , Balasubramaniam Krishnan 
Published: January 2022

Abstract
A method is presented to evaluate the interfacial weakness of aluminium-based honeycomb sandwich structure (HSS) using Shear Horizontal (SH) guided wave. SH guided waves are sensitive to the interfacial properties since the wave particles vibration is oriented parallel to the adhesive-adherent joints. Periodic permanent magnet (PPM) electromagnetic acoustic transducers (EMATs) are used to excite and detect SH-guided waves. A semi-analytical finite element method is developed to simulate the SH wave propagation in HSS. The boundary stiffness approach is used to model the adhesive-adherent interface. The excitation parameters are chosen such that only SH0 mode is generated in the structure. The interaction of the fundamental SH0 wave mode with various defects and the different interface stiffness is analyzed. The frequency-wavenumber analysis is used to study the effect of interface stiffness on SH wave propagation. The analysis reveals that in a perfect bond, SH0 and S0 guided modes are present. The interaction of SH0 mode with the honeycomb core results in the genesis of S0 mode. Thus, the presence or absence of the S0 mode can be used as an indicator of bond quality.
The findings from the FE simulation are validated against the experiment. The analysis shows a reliable non-destructive evaluation of the interface joint and classifying them as good or bad bonds.
Evaluating the Degree of Nonlinearity by Applying the Nonlinear SPC-I Technique in the FEM Simulation of Materials With Breathing Cracks
Authors: Park SeHyuk , Alnuaimi Hamad , Amjad Umar , Kundu Tribikram 
Published: January 2022

Abstract
Detecting internal defects such as fatigue cracks in their early stages is critically important to avoid catastrophic failures. However, detection of micro-scale defects poses a challenge to NDT/SHM (Non-Destructive Testing & Structural Health Monitoring) community. Conventional linear ultrasonic techniques that use absolute time of flight and attenuation to monitor damage progression encounter difficulty in detecting small defects. On the other hand, nonlinear ultrasonic techniques have been proven to be more reliable and sensitive to micro-scale defects. This study uses the nonlinear Sideband Peak Count Index (SPC-I) technique to evaluate the nonlinearity of the material. The problem is simulated using the finite element method (FEM). Fatigue cracks are simulated as breathing cracks. The problem is modeled as an infinite medium to minimize the geometrical effects such as reflections from the boundaries. A narrow band signal is excited and propagated through the material in a single sided excitation/detection setup. The degree of nonlinearity caused by breathing cracks is investigated for multiple configurations. First, the problem is modeled with no cracks to be taken as a reference condition. Then thick crack and thin crack (breathing crack) are modeled, analyzed, and compared. Finally, problems with different number of breathing cracks are simulated and analyzed. All simulated results are compared to investigate the dependence of the degree of nonlinearity on the density and orientation of the cracks.
Linear and Nonlinear Analysis of Additively Manufactured Material With Different Porosity Induced by Varying Material Printing Speed Using Guided Acoustic Waves
Authors: Park SeHyuk , Alnuaimi Hamad , Hayes Anna , Sitkiewicz Madison , Amjad Umar , Muralidharan Krishna , Kundu Tribikram 
Published: January 2022

Abstract
Guided acoustic wave based techniques have been found to be very effective for damage detection, and both quantitative and qualitative characterization of materials. In this research, guided acoustic wave techniques are used for porosity evaluation of additively manufactured materials. A metal 3D printer, Concept Laser Mlab 200 R Cusing™, is used to manufacture 316L additively manufactured (AM) stainless steel specimens. Two levels of porosity are investigated in this study, which was controlled by a suitable combination of scan speed and laser power. The sample with lower level of porosity is obtained with a low scanning speed. Lead Zirconate Titanate (PZT) transducers are used to generate guided acoustic waves. The signal is excited and propagated through the specimens in a single sided transmission mode setup. Signal processing of the recorded signals for damage analysis involves both linear and nonlinear analyses. Linear ultrasonic parameters such as the time-of-flight and magnitude of the propagating waves are recorded. The nonlinear ultrasonic parameter, the Sideband Peak Count Index (SPC-I) is obtained by a newly developed nonlinear analysis technique. Results obtained for both specimens are analyzed and compared using both linear and nonlinear ultrasonic techniques. Finally, the effectiveness of SPC-I technique in monitoring porosity levels in AM specimens is discussed.
Detection of Defects in Titanium Using Shear Horizontal Guided Waves
Authors: Peyton Christian , Edwards Rachel S. , Dixon Steve , Dutton Ben , Vesga Wilson 
Published: January 2022

Abstract
This paper investigates the interaction behaviour between the fundamental shear horizontal guided wave mode and small defects, in order to understand and develop an improved inspection system for titanium samples. In this work, an extensive range of defect sizes have been simulated using finite element software. The SH0 reflection from a defect has been shown previously to depend on its length as the total reflection consists of reflections from both the front and back face. However, for small defect widths, this work has found that the width also affects this interference, changing the length at which the reflection is largest. In addition, the paper looks at how the size of the defect affects the mode converted S0 reflection and SH0 diffraction. The relationship between the SH0 diffraction and defect size is shown to be more complex compared to the reflections. The mode converted S0 reflection occurs at an angle to the incident wave direction; therefore, the most suitable angle for the detection has been found. Simultaneous measurement of multiple waves would bring benefits to inspection.
A Remote Solitary Wave–based Technique for Monitoring Corrosion in Steel Structures: Numerical Analysis and Experimental Validation
Authors: Jalali Hoda , Rizzo Piervincenzo 
Published: January 2022

Abstract
A new corrosion monitoring technique based on the generation and propagation of highly nonlinear solitary waves in 1D granular crystals has been developed recently. In this method, a monoperiodic array of spherical particles, interacting via Hertzian contact forces, is in point contact with the structure or material to be inspected. The array is part of a wireless unit used to induce the wave in the chain and record the solitary waveform remotely. Compared to classical NDE techniques used for thickness monitoring, the developed method is low cost, portable, and simple. This study presents a numerical and an experimental investigation of the sensitivity of solitary waves to localized corrosion. In the experimental study, a corroding steel plate was monitored using solitary waves to examine the effect of corrosion in the plate on the solitary waves interacting with the plate. Furthermore, a discrete element model was coupled with a finite element model to numerically predict the effect of localized corrosion on the delay and the amplitude of the reflected solitary waves formed at the chain-plate interface. The plate was studied in both pristine and corroded conditions. Furthermore, the study investigated customizing the granular chain design to achieve solitary wave-based sensors that can be used in high-temperature environments with maximum sensitivity to corrosion. The numerical results were in good agreement with experimental results and showed that the reflected solitary waves are affected by the presence and the propagation of corrosion in the plate. It was also shown that the sensitivity of the method increases for thinner plates or when the depth of corrosion exceeds half of the plate thickness.
Evaluating Temper Embrittlement in HY-80 Steel Using Magnetic Barkhausen Noise and Microstructural Characterization
Authors: Roberts Michael , D’Ambra Charles , Schibler Jason , Manuel Michele , Krause Thomas W. , Saleem Aroba 
Published: January 2022

Abstract
HY80 steel is a low-carbon steel known for embodying high strength and toughness properties. This steel is used in submarine applications. Temper embrittlement, which is the reduction of fracture toughness, occurs in steels when subject to aging and drastic temperature fluctuations. These changes occur in submarines over time while in underwater environments. During temper embrittlement, impurity atoms and carbides migrate to grain boundaries, which make the steel more susceptible to fracture. A non-destructive testing (NDT) method is desirable to assess the temper embrittlement damage in HY80. Magnetic Barkhausen Noise (MBN) is of interest as being a potential NDT method for analyzing HY80. Focusing on microstructural characterization and its effect on MBN could have implications for establishing an MBN based method to detect varied stages of temper embrittlement in HY80 steel. In this research, samples of HY80 were prepared and heat treated for 16–336 hours to mimic various degrees of temper embrittlement. Microstructural changes with heat treatment were characterized and connected to the MBN produced at each holding time. Methods consisted of performing scanning electron microscopy (SEM) and using an MBN measurement system. It was observed that as holding time increases, grain size increases and carbide density within the grains decreases. These carbides, which act as pinning sites, make it more difficult for domain walls to move, consequently affecting MBN energy.
Edge Illumination X-Ray Phase Contrast Imaging and Ultrasonic Attenuation for Porosity Quantification in Composite Structures
Authors: Shoukroun Dana , Olivo Sandro , Fromme Paul 
Published: January 2022

Abstract
Carbon fiber reinforced composites are widely used in the aerospace industry, due to their low weight and high strength. Porosity often occurs during the manufacturing of composite structures, which can compromise the structural integrity of the part and affect its mechanical properties. In the aerospace industry a typical requirement for structural components is for the porosity content to be kept below 2%. Non-destructive evaluation (NDE) techniques are used to estimate the porosity content in composite components, the most common being ultrasonic attenuation and X-ray computed tomography (CT).
Planar Edge Illumination X-ray Phase Contrast Imaging (EI XPCI) was used to quantify the porosity content in woven carbon fiber reinforced composite plates with porosity ranging between 0.7% and 10.7%. A new metric was introduced, the standard deviation of the differential phase (STDVDP) signal, which represents the variation of inhomogeneity in the plates for features of a scale equal to or above the system resolution (here 12μm). The SDTVDP was found to have a very high correlation with porosity content estimated from matrix digestion and ultrasonic attenuation, hence providing a promising new methodology to quantify porosity in composite plates.
Combined Inductive and Capacitive NDE Technique for Insulator-Conductor Hybrid Structures
Authors: Zhu Ting , Wen Kaijie , Deng Chengjie , Yin Xiaokang , Zhang Xiaorui , Yuan Xinan , Li Wei , Chen Guoming 
Published: January 2022

Abstract
This paper presents a new inductance-capacitance non-destructive detection technique with a form of planar dual-mode sensor. The detection principle of the sensor in mode-L and mode-C was analyzed, and the feasibility of this new combination of inductance and capacitance nondestructive detection technique was demonstrated. A PCB sensor was designed and manufactured, a further research on the characteristic physical field of the designed sensor using finite element simulation software was presented. A suitable detection system was developed to realize this new dual-mode detection technique using this dual-mode detection sensor. Typical test pieces were prepared and tested. The detection results show that the proposed new inductance-capacitance technique can detect typical defects in both insulator and conductor layers of the insulator-conductor hybrid structure with a good balance of inductance and capacitance performance, indicating that this new detection technique can be further used for insulator-conductor hybrid structures non-destructive testing with the potential for structure detection, quantitative evaluation, damage imaging and other applications.
Aboveground Storage Tanks Leak Detection Through Acoustic Emission Sensor Nodes
Authors: Bogomolov Denis , Testoni Nicola , de Marchi Luca , Borzone Tommaso , Terribile Antonio , Giunta Giuseppe , Marzani Alessandro 
Published: January 2022

Abstract
In oil depots and fuel storage facilities, undetected storage tanks damages can lead to the leakage of the oil stored in the soil leading to pollution and economical losses. Leaks are generally due to the perforation of the storage tank floor due to corrosion. The detection of corrosion and leaks is a complicated task, especially for operative tanks with inaccessible floor for detailed inspections and is generally attempted by mean of acoustic emission systems operating from the outer skin of the tank. In this paper, we present a compact sensor node (SN) designed for long-term and real-time acoustic emission monitoring. The SN exploits up to three inexpensive low-frequency sensors based on piezoelectric diaphragms, and it is capable by means of built-in Digital Signal Processing functionalities to process the acquired time waveforms extracting the AE features usually required by testing protocols. An experimental validation on a floating-roof aboveground storage tank 17 m high and 18 m in diameter, filled with water to a level of about 6.2 m, is proposed. Leaks were induced by opening and closing a drainage valve existing at the bottom skirt of the storage tank while acoustic emission signals were recorded at three sensors and processed in real time. Designed nozzles of different diameter, from 1 mm to 9 mm, where used to simulate leakages of different entities.
The results confirm the possibility of detecting and monitoring leaks of various diameters in the low-frequency region 1–2 kHz not traditionally considered by state-of-art acoustic-emission monitoring systems.
Studies on Novel Hyperlens Concept for Ultrasonic Non Destructive Evaluation
Authors: Kumar Pradeep , Syed Akbar Ali Mohamed Subair , Rajagopal Prabhu 
Published: January 2022

Abstract
Ultrasonic imaging is widely preferred in the field of non-destructive evaluation, medical diagnostics, and underwater inspection because it offers various advantages such as safety and versatility. However, conventional ultrasonic imaging methods suffer from the poor resolution limit imposed by the loss of information on fine features within the near-field. Metamaterial concepts have attracted much research interest in recent years, yielding extraordinary benefits such as super-resolution imaging, vibration damping, and cloaking. In the context of imaging, Metalenses allow the successful transfer of the information carried by the evanescent waves to far-field by amplifying them and hence help in overcoming the resolution limit. Hyperlenses enable subwavelength resolution along with spatial magnification by transforming evanescent waves scattered past a material artifact into propagating waves at the far-field ‘imaging’ end of the medium. This paper discusses novel radially symmetric ultrasonic hyperlens for imaging defects in the context of non-destructive evaluation, a topic that has not been studied much. The effect of parameters such as defect extent and distance between the lens on the subwavelength imaging of the hyperlens is studied using numerical simulations. This study investigates the magnification achievable using the proposed hyperlens and the effectiveness of this approach for nondestructive evaluation using cost-effective ‘everyday’ transducers.
Biological Mechanisms Underlying the Aging Process: The Ideas and Techniques of Genetics Are Being Used to Obtain New Insight into the Problems of Aging
Authors: Curtis Howard J. 
Published: January 2022

In this article the several theories put forward to explain the biological mechanisms underlying the aging process are examined. The only ones which attack the problem from the point of view of basic biological mechanisms are the wear-and-tear theory and the somatic mutation theory. The finding that radiation accelerates the aging process is a potent tool for attacking the problem experimentally. Experiments with mice specifically designed to verify the wear-and-tear theory showed conclusively that stress per se does not contribute to aging, and no experimental evidence could be found to support the theory.
On the other hand, a great deal of evidence now available indicates that mutations in somatic cells play a dominant role in aging. It is further shown that the organs having cells which frequently undergo cell division take part in the aging process very little, if at all. Organs having cells which seldom, if ever, divide have no opportunity to throw off either spontaneous or induced mutations, and it is these organs which are responsible for the aging of the animal. Spontaneous mutations build up at a rapid rate in these organs. A cell may continue to function normally long after it has suffered a deleterious mutation, and this accounts for much of the delay in the expression of radiation damage. It is suggested that the mutation rates for somatic cells are very much higher than the rates for gametic cells, and that this circumstance insures the death of the individual and the survival of the species.

Reproduced with permission from
Science
. Copyright 1963 American Association for the Advancement of Science.
Evolution of Human Longevity and the Genetic Complexity Governing Aging Rate
Authors: Cutler Richard G. 
Published: January 2022

The genetic complexity of processes governing the aging rate of humans was estimated by determining the maximum rate at which life-span has evolved along the hominid ancestral-descendant sequence. Maximum life-span potential was found to have increased approximately twofold over the past 3 million years, reaching a maximum rate of increase of 14 years per 100,000 years about 100,000 years ago. It is estimated that about 0.6% of the total functional genes have received substitutions leading to one or more adaptive amino acid changes during this 100,000-year time-period. This suggests that aging is not the result of the expression of a large number of independently acting processes. Instead, primary aging processes appear to exist in which only a few genetic changes are necessary to uniformly decrease the aging rate of many different physiological functions.
Reproduced by permission.

Richard G. Cutler, Evolution of Human Longevity and the Genetic Complexity Governing Aging Rate.
Proc. Natl. Acad. Sci. U.S.A.
72
, 4664-4668 (1975).