bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal and flammability properties of polyethylene composites with fibers to replace natural wood
Authors: Rocha Jairo da Silva , Escócio Viviane A , Visconte Leila LY , Pacheco Élen BAV
Published: March 2021

Composites of high-density polyethylene and lignocellulosic fiber residues from banana, papaya, and peach palm trees, in addition to sponge gourd and coconut fiber, were investigated to identify the least flammable composite as a potential substitute for natural pine wood. The high-density polyethylene/lignocellulosic fiber composites were prepared in a twin-screw extruder, injection molded to obtain specimens, and characterized in terms of thermogravimetry, flammability using the UL-94 burning test and limiting oxygen index, impact resistance and heat deflection temperature. The high-density polyethylene/sponge gourd fiber composite showed the best impact resistance and was selected for further tests, with the addition of 10wt% magnesium hydroxide and (or) rice husk ash as flame retardants. The use of both retardants provided greater thermal stability to the composite. The addition of magnesium hydroxide to the high-density polyethylene/sponge gourd fiber composite improved the flammability properties of horizontal burning and thermal stability and is a potential candidate to replace natural wood.
Reviewing the Structure of Kolb’s Learning Style Inventory From Factor Analysis and Thurstonian Item Response Theory (IRT) Model Approaches
Authors: Calderón Carvajal Carlos , Ximénez Gómez Carmen , Lay-Lisboa Siu , Briceño Mauricio
Published: March 2021

Kolb’s Learning Style Inventory (LSI) continues to generate a great debate among researchers, given the contradictory evidence resulting from its psychometric properties. One primary criticism focuses on the artificiality of the results derived from its internal structure because of the ipsative nature of the forced-choice format. This study seeks to contribute to the resolution of this debate. A short version of Kolb’s LSI with a forced-choice format and an additional inventory scored on a Likert scale was completed by a sample of students of the University Católica del Norte in Antofagasta, Chile. The data obtained from the two forms of the reduced version of the LSI were compared using principal component analysis, confirmatory factor analysis, and the Thurstonian Item Response Theory model. The results support the hypothesis of the existence of four learning mode dimensions. However, they do not support the existence of the learning styles as proposed by Kolb, indicating that said reports are the product of the artificial structure generated by the ipsative forced-choice format .
From Treasure to Trash: The Changing Meaning of Books in the New Social Economy of Higher Education
Authors: Lyng Stephen
Published: March 2021

This paper draws on the findings of an autoethnographic study to discuss significant changes in the character of US institutions of higher education in recent decades. The autoethnography incorporates two forms of evidence: first, a dataset generated from the author’s experiences, observations, communications, and interactions over a 40-year career as a college professor in a wide range of academic settings, and second, a specific event that occurred just weeks before the author’s formal retirement from full-time academic employment. The latter event proved to be analytically important as a crystallizing experience for making sense of the larger body of data collected over the author’s academic career. The event serves as a dramatic illustration of profound changes in how various academic constituencies have come to define the meaning and value of academic books. The paper proposes that the changing meaning of books among key academic actors can be viewed as an important signifier of broader social-economic trends in higher education in the postwar era.
Risk Perception, Preventive Behavior, and Medical Care Avoidance among American Older Adults During the COVID-19 Pandemic
Authors: Lu Peiyi , Kong Dexia , Shelley Mack
Published: March 2021

Objectives: This study investigated the predictors of risk perception and its effect on older adults’ preventive behavior and/or medical care avoidance during the COVID-19 pandemic. Methods: Older respondents (age >50 years) from the MIT COVID-19 Preventive Health Survey reported their social distancing, hand washing, mask wearing, and medical care avoidance between July and October 2020 ( n = 4395). Structural equation models were used. Results: Significant predictors of higher risk perception were female gender, older age, poorer health, city residency, personally knowing someone who had COVID-19, and correct knowledge of vaccine/treatment. Higher risk perception was subsequently associated with higher frequency/probability of practicing preventive behavior and/or avoiding medical care. Knowledge had the strongest path coefficient with risk perception. Discussion: Disseminating correct information to older adults could help them evaluate infection risk accurately. Educational programs on the precautions implemented at clinical settings to ensure patient safety may encourage older adults to seek timely medical care.
Social Isolation Among Older Adults in Long-Term Care: A Scoping Review
Authors: Boamah Sheila A. , Weldrick Rachel , Lee Tin-Suet Joan , Taylor Nicole
Published: March 2021

Objectives: A wealth of literature has established risk factors for social isolation among older people; however, much of this research has focused on community-dwelling populations. Relatively little is known about how risk of social isolation is experienced among those living in long-term care (LTC) homes. We conducted a scoping review to identify possible risk factors for social isolation among older adults living in LTC homes. Methods: A systematic search of five online databases retrieved 1535 unique articles. Eight studies met the inclusion criteria. Results: Thematic analyses revealed that possible risk factors exist at three levels: individual (e.g., communication barriers), systems (e.g., location of LTC facility), and structural factors (e.g., discrimination). Discussion: Our review identified several risk factors for social isolation that have been previously documented in literature, in addition to several risks that may be unique to those living in LTC homes. Results highlight several scholarly and practical implications.
Skyhook control strategy for vehicle suspensions based on the distribution of the operational conditions
Authors: Papaioannou Georgios , Koulocheris Dimitrios , Velenis Efstathios
Published: March 2021

In this work, a novel distribution-based control strategy of semi-active vehicle suspensions is tested under different conditions. The novelty lies in the use of an appropriate threshold in the operational condition of the control algorithm, with which the operational conditions severity is quantified and the state of the damper is controlled according to the magnitude of the operational conditions and not their sign. The value of the threshold depends on the vibrations induced to the sprung mass by the road profile. In order to be evaluated, the operational conditions of the algorithm are fitted to a t-student distribution. The cumulative distribution function of this distribution is used in order to decrease the fraction of the sample operating with the damper’s stiff state. The strategy is applied to traditional SH control algorithms and is tested using a quarter car model excited by different road excitations. A sensitivity analysis for various threshold values is performed, investigating the impact of adopting the cumulative distribution functioned (CDF) controller to various performance metrics. The results illustrate an increase of up to 13% in the ride comfort of the passengers and increase of 6% in the road holding of the vehicle. Both are achieved by minimizing the switches of the damping ratio up to 80%.
Pose estimation of a fast tumbling space noncooperative target using the time-of-flight camera
Authors: Wang Qi-shuai , Cai Guo-ping
Published: March 2021

This article proposes a pose estimation method for a fast tumbling space noncooperative target. The core idea of this method is to extract the target’s body-fixed coordinate system by using the geometric characteristics of the target’s point cloud and then by the body-fixed coordinate system to realize pose initialization and pose tracking of the target. In the extraction of the body-fixed coordinate system, a point cloud of the target, which can be obtained by a time-of-flight camera, can be divided into small plane point clouds firstly; then the geometric information of these plane point clouds can be utilized to extract the target’s descriptive structures, such as the target surfaces and the solar panel supports; and finally the body-fixed coordinate system can be determined by the geometric characteristics of these structures. The body-fixed coordinate system obtained above can be used to determine the pose of consecutive point clouds of the target, that is, to realize the pose initialization and the pose tracking, and accumulated bias often emerges in the pose tracking. To mitigate the accumulated bias, a pose graph optimization method is adopted. In the end of this article, the performance of the proposed method is evaluated by numerical simulations. Simulation results show that when the distance between the target and the chaser is 10 m, the errors of the estimation results of the target’s attitude and position are 0.025° and 0.026 m, respectively. This means that the proposed method can achieve high-precision pose estimation of the noncooperative target.
Aerodynamics with state-of-the-art bioinspired technology: Tubercles of humpback whale
Authors: Gopinathan VT , Bruce Ralphin Rose J
Published: March 2021

Bioinspired aerodynamics is an emerging subject in the design of advanced flight vehicles with superior performance and minimum fuel consumption. In the present review article, a comprehensive evaluation is focused on previous studies and investigations toward the performance enhancement of aerodynamic surfaces with leading-edge (LE) tubercles. The implementation of tubercles has been biologically imitated from humpback whale (HW) flippers. Particularly, aerodynamicists are much interested in this bioinspired technology because of the exclusive maneuvering and flow control potential of HW flippers. LE protuberances are considered as a passive flow control method to improve the aerodynamic performance in various applications like aviation, marine, and wind energy. The aerodynamic and hydrodynamic performance variations caused by specific tubercles amplitude and wavelength are also compared through numerical and wind tunnel testing. The prospective utilization of tubercles on boundary layer flow control is measured with regard to conventional and swept-back wing designs. Flow control mechanisms of tubercles are outlined with several interesting facts in addition to the outcomes of various bioinspired aerodynamic investigations in the recent years.
A method for predicting Mach stem height in steady flows
Authors: Choe Song-Guk
Published: March 2021

The prediction of Mach stem height can be important in the design of supersonic intake in supersonic and hypersonic flows. It is also important because of the progress in aircraft and rocket engines. An analytical method of predicting the Mach stem height is necessary in theoretical field of shock reflection and is the basis of the comparable computational fluid dynamics (CFD) method. A method for predicting the Mach stem height in steady flows is performed based on the earlier models. In this article, an analytical model for predicting the Mach stem height is improved based on two main assumptions: one is the calculation of the triple point deflection angle when the Mach stem is an oblique shock and the other is about the shape of the free part of the slip line. Under these assumptions, the relations predicting of Mach stem height in two-dimensional steady flow are derived based on the advanced averaging method of the subsonic flow region. The Mach stem heights are decided solely for the incoming flow Mach numbers and the wedge angles by the improved analytical model. As a result, the Mach stem heights by the model of this article are found to agree well with experimental results at lower Mach numbers, but there are relative errors at higher Mach numbers. The convexity of the slip line is also considered.
The maximum taxiing safe set of the wheel-skid aircraft under optimal control of rudder
Authors: Liang Taotao , Yin Qiaozhi , Fang Wuguan , Wei Xiaohui , Nie Hong
Published: March 2021

Directional stability during the roll-out phase is crucial to the safety and reusability of the aircraft. Because of the mechanical properties, the wheel-skid aircraft is more prone to produce course instability. To address this issue, the taxiing safe set of the wheel-skid aircraft is discussed based on the reachability theory. A dynamic model of the on-ground aircraft is established firstly, considering the complex condition of the ground loads. Then, the particular Hamilton–Jacobi partial differential equation is used to obtain the safe set. According to the safe set results, the optimal control of the rudder is built in the state space. Its effectiveness is verified by the comparison with other robust methods. In addition, three structural parameters are selected to analyze the influences on the safe set. Results indicate that the maximum safe yaw angle increases from [Formula: see text] to [Formula: see text] at 70 m/s under the optimal control of the rudder when the steering of nose wheel is locked. The safe boundary in the middle–high-speed region expands by 43.5% under the rudder control. Because of the mechanical properties, uncontrollable deflection will appear due to the asymmetric disturbances when the longitudinal velocity is lower than 42 m/s.
Design of the symmetric tuned mass damper for torsional vibration control of the rotating shaft
Authors: Nguyen Duy-Chinh
Published: March 2021

The shaft is one of the most important parts of the machine, and it is used to transmit torque. However, the shaft does not always rotate at constant angular velocity due to sudden acceleration or deceleration or due to unstable current. The rotation of the shaft varies with time, which causes torsional vibration on the rotating shaft. To the best of the author’s knowledge, there is no study on designing a symmetric tuned mass damper (STMD) for the rotating shaft with variable angular velocity. Therefore, the purpose of this study is to design an optimal STMD to reduce torsional vibration for the rotating shaft with variable angular velocity. First, the author designs an optimal STMD for the rotating shaft by the fixed-points theory. Second, the optimal parameters of the STMD are obtained by using the minimum quadratic torque method. The optimal parameters of the STMD are defined in analytic and explicit forms, helping researchers to easily design an optimal STMD when applying to reduce torsional vibration for the rotating shaft. Finally, to evaluate the reliability of the designed optimal STMD, Maple software is used to simulate the vibration of the rotating shaft attached with the optimal STMD, as well as to help the readers to have a visual view on the effect of reducing torsional vibration of the rotating shaft.
L1 Adaptive integrated guidance and control for flexible hypersonic flight vehicle in the presence of dynamic uncertainties
Authors: Khankalantary Saeed , Rezaee Ahvanouee H , Mohammadkhani Hassan
Published: March 2021

In this article, an integrated guidance and control design method for general nonlinear flexible hypersonic flight vehicles in the presence of dynamic uncertainties based on the [Formula: see text] adaptive state feedback control approach is presented. Initially, the 6-degree-of-freedom integrated guidance and autopilot dynamic model is organized using the combination of flexible uncertain hypersonic flight vehicle dynamic model and hypersonic flight vehicle-target relative motion model whereas aerodynamic and model uncertainties, cross-coupling effects, and disturbances are considered. The proposed integrated guidance and control method based on [Formula: see text] adaptive control scheme afterward is designed to realize control objectives including closed-loop stability, high-performance target interception, state regulation, uncertainties compensation, and reduction of the adverse flexibility effects on the overall performance. The whole Targets are proven thereupon based on the Lyapunov theory. Finally, the three-dimensional simulation results confirm the effectiveness of suggested integrated guidance and control law not only in closed-loop stability but also in high-performance target interception using the smooth control input.
An online estimation algorithm to predict external forces acting on a front-end loader
Authors: Madau Riccardo , Colombara Daniele , Alexander Addison , Vacca Andrea , Mazza Luigi
Published: March 2021

One of the most significant goals of earthmoving equipment is to maximize productivity during loading cycles. A real-time knowledge of the forces exchanged between the machine implement and the surrounding, that is, while digging, can be used in different ways to increase productivity. It can be used to determine the amount of material moved by the machine; or to find the optimal bucket trajectory; moreover, as input to traction control systems. This article presents an online force estimation algorithm able to predict vertical and horizontal forces exchanged between the front-loader and the surrounding environment, as well as the reaction forces through the implement itself. Taking the case of a 14-ton wheel loader as reference, this article illustrates the development of a simulation model for the analysis of the machine digging system, along with the instrumentation and testing of the proposed estimation algorithm. The model is divided into two sections describing, respectively, system kinematic and system dynamics. The kinematic model of the front-loader is compared against measurements, and results show an average error lower than 1%. The dynamic model predicts both hydraulic and dynamic features of the machine implement, achieving an accuracy on the payload mass within 2%–3%, even during dynamic conditions. The estimated pushing force reflects the expected behavior when tested for various pushing efforts and in different ground conditions. Eventually, the algorithm was tested on a complete loading cycle and the results show good consistency considering the measured front-loader trajectory and vehicle speed. The proposed model overcomes some drawbacks of the currently used technologies. For example, it allows for an online estimation of the bucket forces for any position of the implement. Although the results discussed in this article pertain to a specific reference machine, the proposed method can be extended to most wheel loaders equipped with standard digging equipment.
Establishment and functioning of the savanna marshes of the Lopé National Park in Gabon since the termination of the African humid period and the arrival of humans 2500 years ago
Authors: Bremond Laurent , Oslisly Richard , Sebag David , Bentaleb Ilham , Favier Charly , Henga-Botsikabobe Karl , Mvoubou Makaya , Ngomanda Alfred , de Saulieu Geoffroy ,   Ecotrop Team
Published: March 2021

Holocene paleoecological studies in tropical Africa are rare because most lakes either dried out at the termination of the African Humid Period or have since filled up. However, tropical sedge marshes can be an alternative to perform long-term ecological studies. The Lopé National Park (LNP) in Gabon is a mosaic of forest and savanna enclosed in the equatorial forest, where open areas facilitated the development of peat marshes accumulating several-meter-thick sediment. In order to reconstruct the historical dynamic in these marshes through a local and regional point of view, we compared sedimentological, continuous X-ray fluorescence, and stable isotopic analyses on sediment cores from six herbaceous marshes in the LNP. A reliable chronological frame was based on 50 14C dates, over the last 2500 years in most sites, and reaching 9000 years in one marsh. We show that the origin of these marshes is a major hydrological change, 3450 and 2300 years ago, that affected the entire region, almost concomitantly with the diffusion of Iron Age population. The sedimentation within marshes is homogenous with low intra-site variability. In contrast, high inter-sites variability evidences that the functioning of the marsh itself exerts a much more significant influence than in lakes. However, a regional event is recorded between 1400 and 800 years ago, concurrently with an archeological trace hiatus throughout the forest hinterland of West Central Africa.
Applying Public Health Principles to Better Manage the COVID-19 Pandemic: “Community Participation,” “Equity,” and “Cultural Sensitivity”
Authors: Mahmood Mohammad Afzal , Khan Kausar Saeed , Moss John Robert
Published: March 2021

Although coronavirus vaccine roll-out is beginning, standard public health practices will, for most people, remain their first line of protection for some time. Three principles guiding the pandemic control process, namely community participation, promotion of equity, and cultural sensitivity, can help people adhere to public health advice. These three principles can enhance intervention effectiveness, decreasing the rate of infection and protecting human rights, promoting social harmony and preventing unrest.
Aristotle: Mentor for the Soul
Authors: Shaw Julia Penn
Published: March 2021

Aristotle serves as a valuable, and practical, model for mentors of adult learners. His writings give insight into mentoring even as we practice it today. Although he lived in ancient Greece (c. 384 BCE to 322 BCE) and his audience was aristocratic males, the tenets of his philosophy for adult learning hold true in the present age for learners of any race, class, or gender because they are built on human attributes common to us all. Written from the author’s perspective of more than 15 years of mentoring diverse adult learners, this article distills some principles for mentoring from Aristotle’s work that resonate with current practice: (a) mentor the soul, (b) understand the student’s “puzzle,” (c) trust our senses, and (d) develop excellence. Aristotle ideas give “form” to the task of mentoring, honoring excellence as a virtue to be sought—and achieved—in everyday actions. It is heartening to view the mentoring that we do today as part of a very long and very rich tradition, foundational to Western Civilization.
Quantitative Evaluation of Ankle Instability Using a Capacitance-Type Strain Sensor
Authors: Teramoto Atsushi , Iba Kousuke , Murahashi Yasutaka , Shoji Hiroaki , Hirota Kento , Kawai Makoto , Ikeda Yuma , Imamura Rui , Kamiya Tomoaki , Watanabe Kota , Yamashita Toshihiko
Published: March 2021

Background:

Manual evaluation is an important method for assessing ankle instability, but it is not quantitative. Capacitance-type sensors can be used to measure the distance on the basis of the capacitance value. We applied the sensor to the noninvasive device for measuring ankle instability and showed its utility.

Methods:

First, 5 ankles embalmed by Thiel’s method were used in an experiment using a cadaver. The capacitance-type sensor was fixed alongside the anterior talofibular ligament (ATFL) of a specially made brace, and the anterior drawer test was performed. The test had been performed for the intact ankle, with the ATFL transected and with both the ATFL and calcaneofibular ligament (CFL) transected. The anterior drawer distance was calculated by the sensor. Intra- and interinvestigator reliability were also analyzed. Next, as a clinical study, a brace with a sensor was fitted to 22 ankles of 20 patients with a history of ankle sprain. An anterior drawer test at a load of 150 N was conducted using a Telos stress device. The anterior drawer distances measured by the sensor and based on radiographic images were then compared.

Results:

The mean anterior drawer distances were 3.7 ± 1.0 mm for the intact cadavers, 6.1 ± 1.6 mm with the ATFL transected ( P < .001), and 7.9 ± 1.8 mm with the ATFL and CFL transected ( P < .001). The intrainvestigator intraclass correlation coefficients (ICCs) were 0.862 to 0.939, and the interinvestigator ICC was 0.815. In the experiments on patients, the mean anterior drawer distance measured by the sensor was 2.9 ± 0.9 mm, and it was 2.7 ± 0.9 mm for the radiographic images. The correlation coefficient between the sensor and the radiographic images was 0.843.

Conclusion:

We quantitatively evaluated anterior drawer laxity using a capacitance-type sensor and found it had high reproducibility and strongly correlated with stress radiography measurements in patients with ankle instability. Capacitance-type sensors can be used for the safe, simple, and accurate evaluation of ankle instability.
Stability of asymmetric rotors with asymmetric flexible disks
Authors: Khader Naim
Published: March 2021

The presented work examines the dynamic behavior of an asymmetric rotor with asymmetric flexible disk, contrary to previous works on the subject, where researchers examined the effect of either rigid disk asymmetry or disk flexibility at a time. Account for the asymmetry of flexible disk in rotors constitutes the new contribution in this work. The suggested mathematical model combines Lagrangian approach with Rayleigh–Ritz method to derive the governing equations of motion of the rotor. Account for asymmetry of the flexible disk results in complicated and lengthy expressions for the potential and kinetic energies of the rotor, required in the adopted Lagrangian approach. Using symbolic computation simplified the derivation of the governing equations of motion with constant coefficients in terms of rotating coordinate system. Solution of the resulting eigenvalue problem provided numerical results for rotors with symmetric and asymmetric flexible disks, required to assess the effect of disk flexibility and asymmetry on the resulting frequencies and stability boundaries of the examined rotor system.
Acoustic meta-silencer: Toward enabling ultrawide-band air-permeable noise barrier
Authors: Khodaei Mohammad Javad , Mehrvarz Amin , Ghaffarivardavagh Reza , Jalili Nader
Published: March 2021

In this article, we have first presented a metasurface design methodology by coupling the acoustic cavity to the coiled channel. The geometrical design parameters in this structure are subsequently studied both analytically and numerically to identify a road map for silencer design. Next, upon tuning the design parameters, we have introduced an air-permeable noise barrier capable of sound silencing in the ultrawide band of the frequency. It is has been shown that the presented metasurface can achieve +10 dB sound transmission loss from 170 Hz to 1330 Hz (≈3 octaves). Furthermore, we have numerically studied the ventilation and heat transfer performance of the designed metasurface. Enabling noise mitigation by leveraging the proposed metasurface opens up new possibilities ranging from residential and office noise reduction to enabling ultralow noise fan, propellers, and machinery.
Enhanced variable universe fuzzy proportional–integral–derivative control of structural vibration with real-time adaptive contracting–expanding factors
Authors: Liu Gang , Jiang Wei , Wang Qi , Wang Tao
Published: March 2021

A conventional variable universe fuzzy proportional–integral–derivative control approach is widely used for semi-active control in mechanical engineering. The performance of the controller is dependent on an optimal selection of parameters of the contracting–expanding factors. An improved variable universe fuzzy proportional–integral–derivative control algorithm is developed in this study where these parameters are automatically determined in real-time according to the error in the controlled responses and its change rate based on fuzzy logic control. The proposed method is numerically and experimentally illustrated with a three-story frame structure with a magnetorheological damper. The amplitude of displacement, velocity, and acceleration at all floor levels under the proposed control method are smaller than those obtained from existing proportional–integral–derivative, fuzzy, and conventional variable universe fuzzy methods.
Dynamic characterization of a master–slave robotic manipulator using a hybrid grey wolf–whale optimization algorithm
Authors: Obadina Ololade O , Thaha Mohamed A , Althoefer Kaspar , Shaheed Mohammad H
Published: March 2021

This article presents a novel hybrid algorithm based on the grey-wolf optimizer and whale optimization algorithm, referred here as grey-wolf optimizer–whale optimization algorithm, for the dynamic parametric modelling of a four degree-of-freedom master–slave robot manipulator system. The first part of this work consists of testing the feasibility of the grey-wolf optimizer–whale optimization algorithm by comparing its performance with a grey-wolf optimizer, whale optimization algorithm and particle swarm optimization using 10 benchmark functions. The grey-wolf optimizer–whale optimization algorithm is then used for the model identification of an experimental master–slave robot manipulator system using the autoregressive moving average with exogenous inputs model structure. Obtained results demonstrate that the hybrid algorithm is effective and can be a suitable substitute to solve the parameter identification problem of robot models.
Modal characteristics and fluid–structure interaction vibration response of submerged impeller
Authors: Huo Shihui , Huang Hong , Huang Daoqiong , Liu Zhanyi , Chen Hui
Published: March 2021

Turbo pump is one of the elements with the most complex flow of liquid rocket engine, and as an important component of turbo pump, an impeller is the weak point affecting its reliability. In this study, a noncontact modal characteristic identification technique was proposed for the liquid oxygen pump impeller. Modal characteristics of the impeller under three different submerged media, air, pure water, and brine with same density as liquid oxygen, were tested based on the noncontact modal identification technology. Submersion state directly affects the modal frequencies and damping ratio. The transient vibration response characteristics of the impeller excited by the unsteady flow field was achieved combining with unsteady flow field analysis and transient dynamic analysis in the whole flow passage of the liquid oxygen pump. Vibration responses at different positions of the impeller show 10X and 20X frequencies, and the amplitude at the root of short blade is significant, which needs to be paid more attention in structural design and fatigue evaluation.
On the efficient evaluation of modal density and damping of one-dimensional periodic structures using a dynamic homogenization method
Authors: Ma Yongbin , Deng Zichen
Published: March 2021

Modal density and damping are key parameters for structural vibration analysis. However, the current methods for calculating these properties of periodic structures in high-frequency environment are still insufficient in accuracy and efficiency. In this article, a semi-analytical form for the modal density and damping of longitudinal vibration of one-dimensional periodic structures is proposed based on a dynamic homogenization method. By virtue of asymptotic perturbation expansion, explicit expression is obtained for the dispersion relation. And then, the modal density is obtained in terms of the semi-analytical form by differentiating frequency with respect to wave number. By noting that the high-frequency homogenization method is valid only in the neighborhood of the standing wave frequencies, a weighted technique is introduced to compensate this deficiency. Based on the mode strain energy method, the damping loss factor is also obtained using the high-frequency homogenization results. Because explicit expression can be obtained analytically, the shortage of low computational efficiency and accuracy faced by traditional analysis is significantly made up by the proposed method, which is confirmed by numerical examples.
Maher as the Location of Origin: Examining Home and Displacement in Geo-Familial, Academic, and Spiritual Contexts
Authors: Thatte Asavari
Published: March 2021

In this article, I examine the construct of parental home or maher in my native language Marathi—as a social, emotional, cultural, spiritual, physical, and lived construct. Maher informs my struggle to comprehend the construct of home and its relationship to displacement, loss of familiarity, nostalgia, and the liminal. I juxtapose my experiences of being a newly married woman of Indian origin in the United States, with my experiences of being a new graduate student in a reputed North American university—both simultaneous life events. This article is an autoethnographical reflection on my negotiation of my marital and academic landscapes where I found my identity and ontological orientations challenged. The borderlands that resulted from geo-familial displacement and ontological displacement in academia intersected to create vantage points and liminal spaces that allowed me to explore, re-orient, and assert my ontological roots that are informed by Indian philosophy—specifically, the Advaita Vedanta approach. This article explores the power of art as research and the process of art-making as a process synchronous to researching to explore identity in the making.
Use of therapeutic outcomes monitoring method for performing of pharmaceutical care in oncology patients
Authors: Cataldo Renata RV , Manaças Liliane AR , Figueira Priscila HM , Ferraz Carla VG , Calil-Elias Sabrina
Published: March 2021

This study aimed to implement pharmaceutical care using the therapeutic outcome monitoring (TOM) method for pharmacotherapeutic follow-up of oncological patients. This was a prospective longitudinal study involving patients undergoing oral chemotherapy. The study environment was an outpatient pharmacy at a tertiary-level oncology hospital. Ninety patients who received oral chemotherapy were evaluated, and 27 patients were followed up in accordance with the exclusion criteria and acceptability of participation in the study. The patients were predominantly diagnosed with gynecological tumors, with a mean age of 57.56 ± 13.06. The average consumption of drugs per patient was 4.63 ± 4.85, and more than 55% of patients had undergone oral antineoplastic therapy for more than a year. The main therapeutic groups used were drugs that acted on the gastrointestinal tract and metabolism (34%). All patients had at least one drug-related problem (DRP). In total, 133 DRP were identified. Approximately 33% of patients had DRPs related to antineoplastic therapy; non-adherence, incorrect administration, and the probability of adverse events were among the frequently reported DRPs. We identified 43 negative outcomes associated with medication (NOM), with untreated health problems (47%) and non-quantitative insecurity (30%) being the most frequently reported. 81 pharmaceutical interventions were performed, and 96% were accepted. The main errors avoided with the interventions were untreated health problems, misuse, and interruptions associated with medication administration. The TOM method effectively achieved the desired results of therapy, improving the use of medicines, and thus increasing patient safety.
Ifosfamide-related encephalopathy with severe clinical presentations in children with cancer
Authors: Ataseven Eda , Göktepe Şebnem Önen , Kantar Mehmet
Published: March 2021

Introduction

Ifosfamide is an alkylating agent, mostly used against variety of solid tumors in pediatric oncology practice. Although hemorrhagic cystitis is known as a common adverse effect, encephalopathy is the another one that should be kept in mind. It may occur in 2–5% of the children, and manifested by different clinical spectrums such as somnolence, lethargy, irritability, excitement, disorientation, confusion, weakness, hallucinations, seizures, movement disorders, and coma.

Case report

Herein, we present two patients who developed generalized seizure activity and one who developed coma during ifosfamide infusion. Management and outcome: In the first two patients, ifosfamide infusion was discontinued and intravenous diazepam was given. Their seizure stopped in a few minutes and neurological examination was back to normal, and no focal deficits were observed. In the third patient, ifosfamide infusion was discontinued, methylene blue and thiamine were given. After the tenth dose of methylene blue, she became neurologically normal, without any mental and motor deficit. Nevertheless, later she developed febrile neutropenia, septic shock and she died.

Discussion

These cases highlight that pediatric oncologists and hematologists should be aware of possibility of severe neurological toxicity after administration of ifosfamide in adolescent patients. Apart from seizure, clinicians should also be prepared to notice drowsiness during ifosfamide infusions in children. Most of the time cessation of ifosfamide and hydration is enough. However, in severe toxicities there is a risk of irreversible neurological damage, and for these patients methylene blue (MB) and thiamine treatment should be kept in mind.
Pluralistic Ignorance Research in Psychology: A Scoping Review of Topic and Method Variation and Directions for Future Research
Authors: Sargent Rikki H. , Newman Leonard S.
Published: March 2021

Pluralistic ignorance occurs when group members mistakenly believe others’ cognitions and/or behaviors are systematically different from their own. More than 20 years have passed since the last review of pluralistic ignorance from a psychological framework, with more than 60 empirical articles assessing pluralistic ignorance published since then. Previous reviews took an almost entirely conceptual approach with minimal review of methodology, making existing reviews outdated and limited in the extent to which they can provide guidelines for researchers. The goal of this review is to evaluate and integrate the literature on pluralistic ignorance, clarify important conceptual issues, identify inconsistencies in the literature, and provide guidance for future research. We provide a comprehensive definition for the phenomenon, with a focus on its status as a group-level phenomenon. We highlight three areas of variation in particular in the current scoping review: variation in topics assessed, variation in measurement, and (especially) variation in methods for assessing the implications of individual-level misperceptions that, in aggregate, lead to pluralistic ignorance. By filling these gaps in the literature, we ultimately hope to motivate further analysis of the phenomenon.
In Silico Analysis of Partial Fatty Acid Desaturase 2 cDNA From Reutealis trisperma (Blanco) Airy Shaw
Authors: Jadid Nurul , Prasetyowati Indah , Rosidah Nur Laili Alfina , Ermavitalini Dini , Nurhatika Sri , Nurhidayati Tutik , Purnobasuki Hery
Published: March 2021

Reutealis trisperma oil is a new source for biodiesel production. The predominant fatty acids in this plant are stearic acid (9%), palmitic acid (10%), oleic acid (12%), linoleic acid (19%), and α-eleostearic acid (51%). The presence of polyunsaturated fatty acids (PUFAs), linoleic acid, and α-eleostearic acid decreases the oxidation stability of R. trisperma biodiesel. Although several studies have suggested that the fatty acid desaturase 2 (FAD2) enzyme is involved in the regulation of fatty acid desaturation, little is known about the genetic information of FAD2 in R. trisperma. The objectives of this study were to isolate, characterize, and determine the relationship between the R. trisperma FAD2 fragment and other Euphorbiaceae plants. cDNA fragments were isolated using reverse transcription polymerase chain reaction (PCR). The DNA sequence obtained by sequencing was used for further analysis. In silico analysis identified the fragment identity, subcellular localization, and phylogenetic construction of the R. trisperma FAD2 cDNA fragment and Euphorbiaceae. The results showed that a 923-bp partial sequence of R. trisperma FAD2 was successfully isolated. Based on in silico analysis, FAD2 was predicted to encode 260 amino acids, had a domain similarity with Omega-6 fatty acid desaturase, and was located in the endoplasmic reticulum membrane. The R. trisperma FAD2 fragment was more closely related to Vernicia fordii (HM755946.1).
Chemical Contamination of Soil on Urban Territories With Aluminum Production in the Baikal Region, Russia
Authors: Grebenshchikova Valentina I , Kuzmin Mikhail I , Rukavishnikov Viktor S , Efimova Natalia V , Donskikh Irina V , Doroshkov Artemiy A
Published: March 2021

The study was conducted in 2 urbanized areas of the Baikal region of Russia. These are the cities of Shelekhov and Tayshet with their suburbs. Aluminum production has been carried out in Shelekhov for over 60 years and in Tayshet for 5 years. The purpose of the study was to determine the pollution of urban soils with toxic elements—Al, F, Be, Li, as well as Cr, Ni, Pb, and so on under the influence of industrial enterprises (aluminum and cable plants, thermal power plants). Also, the purpose of the research was to determine the effect of increased fluorite (F) in the environment on children’s health. Pure aluminum is used much less frequently than in alloys. The addition of various elements (Be, B, Li, Fe, Si, Mg, Mn, Zr, Ag, Pb, Cu, Ni, and others) increases the hardness, density, thermal conductivity, and other properties of the alloys. The area of high F content in urban soil is 15 times higher than the regional context. The maximum content of Na, Be, and Al is 2 to 4 times higher than the regional background. An increased Li content is marked only near aluminum smelters. The F content in urine samples from children living in areas with long-term pollution exposure (Shelekhov) is 1.5 to 2 times higher than in the group of children with a short exposure period (Tayshet).
Diffuse Alveolar Hemorrhage after Receiving Oral Levonorgerstrel for Emergency Contraception: A Case Report
Authors: Georgopoulou Athina , Papadopoulou Efthymia , Moyseos Marianna , Zagalioti Sofia-Chrysovalantou , Hatzis Christos , Karanasios Dimitrios , Tryfon Stavros
Published: March 2021

Introduction:

Drug-induced diffuse alveolar hemorrhage (DAH) has been associated with the administration of various medications, among which levonorgestrel (LN) has not been reported until now.

Case Presentation:

This case study describes a 42-year-old woman who presented with hemoptysis, hypoxemia, and radiological depiction of ground glass opacities, 3 days after she had received emergency contraceptive medication containing levonorgestrel. Emergent bronchoscopy was performed, and BAL was diagnostic of diffuse alveolar hemorrhage (DAH). A thorough diagnostic approach was followed, in order to detect the underlying pathological condition that induced DAH. The absence of other identifiable pathological conditions in this patient raised suspicion of LN’s potential causative role.

Conclusion:

DAH has not been reported as an adverse effect of LN until now. However, LN has been found to exert immunomodulatory effects and to present potential for manifestations of vasculitis as well as severe hypersensitivity reactions. These mechanisms may have been implicated in the development of DAH in our patient, who presented no other pathological conditions.
The employment and mental health impact of integrated Improving Access to Psychological Therapies: Evidence on secondary health care utilization from a pragmatic trial in three English counties
Authors: Toffolutti Veronica , Stuckler David , McKee Martin , Wolsey Ineke , Chapman Judith , J Pimm Theo , Ryder Joanne , Salt Heather , M Clark David
Published: March 2021

Objective

Patients with a combination of long-term physical health problems can face barriers in obtaining appropriate treatment for co-existing mental health problems. This paper evaluates the impact of integrating the improving access to psychological therapies services (IAPT) model with services addressing physical health problems. We ask whether such services can reduce secondary health care utilization costs and improve the employment prospects of those so affected.

Methods

We used a stepped-wedge design of two cohorts of a total of 1,096 patients with depression and/or anxiety and comorbid long-term physical health conditions from three counties within the Thames Valley from March to August 2017. Panels were balanced. Difference-in-difference models were employed in an intention-to-treat analysis.

Results

The new Integrated-IAPT was associated with a decrease of 6.15 (95% CI: −6.84 to −5.45) [4.83 (95% CI: −5.47 to −4.19]) points in the Patient Health Questionnaire-9 [generalized anxiety disorder-7] and £360 (95% CI: –£559 to –£162) in terms of secondary health care utilization costs per person in the first three months of treatment. The Integrated-IAPT was also associated with an 8.44% (95% CI: 1.93% to 14.9%) increased probability that those who were unemployed transitioned to employment.

Conclusions

Mental health treatment in care model with Integrated-IAPT seems to have significantly reduced secondary health care utilization costs among persons with long-term physical health conditions and increased their probability of employment.
Association between single session service attendance and clinical characteristics in administrative data
Authors: Edbrooke-Childs Julian , Hayes Daniel , Lane Rebecca , Liverpool Shaun , Jacob Jenna , Deighton Jessica
Published: March 2021

A large proportion of young people accessing specialist mental health services do so for a single session. The aim of the present study was to examine the characteristics of young people attending specialist mental health services for a single session and to examine associations between single session attendance and clinical characteristics. Secondary analysis of administrative data on N = 23,300 young people (mean age = 12.73 years, 57% female, 64% White British) was conducted. The mean number of sessions attended was 4.33 and 46% (10,669) attended for a single session. Multilevel logistic regression analysis showed that younger children, Black young people (OR = 1.20, 95% CI = 1.01–1.43) or those whose ethnicity was not stated (OR = 1.25, 95% CI = 1.15–1.35), young people with peer relationship difficulties (OR = 1.11, 95% CI = 1.04–1.19) or low frequency problems (OR = 1.06, 95% CI = 0.99–1.14), and those with more complexity factors (OR = 1.07, 95% CI = 1.04–1.10) were more likely to attend services for a single session. The present study sets out research questions to prompt future research: (1) the experience of attending services for a single session, (2) identifying groups of single session attenders who do not require further support compared to those who are not able to sustain engagement with more sessions, and (3) whether new care pathways are needed for these groups who currently access specialist mental health services for a single session.
Self-compassion as predictor of daily physical symptoms and chronic illness across older adulthood
Authors: Herriot Heather , Wrosch Carsten
Published: March 2021

This study examined whether self-compassion could benefit daily physical symptoms and chronic illness in early and advanced old age. The hypotheses were evaluated in a 4-year longitudinal study of 264 older adults. Results showed that self-compassion predicted lower levels of daily physical symptoms across the study period in advanced, but not early, old age ( T-ratio = −1.93, p = 0.05). In addition, self-compassion was associated with fewer increases in chronic illness in advanced, but not early, old age ( T-ratio = − 2.45, p < 0.02). The results of this study suggest that self-compassion may be particularly adaptive towards the end of life.