bluuebunny/crossref_metadata_2025 huggingface dataset:
Why don't children in Uganda have tics? A mixed‐methods study of beliefs, knowledge, and attitudes of health professionals
Authors: Rodin Abigail , Fleetwood‐Meade Kirstie , Gilmour Jane , Kasujja Rosco , Murphy Tara
Published: February 2020

Background

Tourette syndrome (TS) is reported in all cultures, although is speculated to be rare among those of Sub‐Saharan African descent. A lack of research exploring TS in the context of Sub‐Saharan Africa has meant that it is not yet established whether this apparent rarity is due to a true low prevalence or if identification of the condition merely is unrecognized. The present study aimed to explore health professionals’ knowledge and attitudes of the identification, diagnosis and management of TS in Uganda.

Method

A mixed‐methods design was used to collect data from 152 Ugandan healthcare professionals by survey. Of these, 6 professionals took part in semi‐structured interviews. Data gathered were analyzed with descriptive statistics and qualitatively using thematic analysis.

Results

Professionals’ views and experiences led to conclusions addressing (a) perceived challenges in diagnosing and treating TS in a Ugandan healthcare setting, (b) the role of cultural factors in help‐seeking behaviors, and (c) ways by which efforts can be made to build capacity in awareness and clinical care.

Conclusions

The findings suggest that TS is present in Uganda, but a number of factors hinder detection rates causing it to be under‐reported in the population. This study highlights the need for more focused and adequate training for all healthcare professionals in Uganda and education campaigns to increase awareness among the general public.

Key Practitioner Message

Little is currently known about the presentation of or understanding by professionals around Tourette syndrome in Sub‐Saharan Africa.

This study found health professionals in Uganda indicated a number of factors which interact and negatively impact recognition rates of tic disorders. This included limited training, exposure, and misconceptions, contributing to a lack of clinical awareness and attention.

They also reported a lack of help‐seeking behaviors due to parental perceptions and Ugandan traditional, cultural and religious beliefs.

Professionals perceive that there are likely large numbers of undiagnosed and untreated children with Tourette syndrome in Uganda.

This supports existing literature regarding the diagnostic challenges of neurodevelopmental disorders in Africa and provides an alternative explanation for the assumption that tic disorders may be rare and possible absent in Sub‐Saharan Africa.

There is a need to develop adequate training regarding tic disorders for all healthcare professionals working in Uganda as well as education campaigns for the general public to increase awareness.
ConceptGraph: A Formal Model for Interpretation and Reasoning During Visual Analysis
Authors: Karer B. , Scheler I. , Hagen H. , Leitte H.
Published: February 2020

In order to discuss the kinds of reasoning a visualization supports and the conclusions that can be drawn within the analysis context, a theoretical framework is needed that enables a formal treatment of the reasoning process. Such a model needs to encompass three stages of the visualization pipeline: encoding, decoding and interpretation. The encoding details how data are transformed into a visualization and what can be seen in the visualization. The decoding explains how humans construct graphical contexts inside the depicted visualization and how they interpret them assigning meaning to displayed structures according to a formal reasoning strategy. In the presented model, we adapt and combine theories for the different steps into a unified formal framework such that the analysis process is modelled as an assignment of meaning to displayed structures according to a formal reasoning strategy. Additionally, we propose the ConceptGraph, a combined graph‐based representation of the finite‐state transducers resulting from the three stages, that can be used to formalize and understand the reasoning process. We apply the new model to several visualization types and investigate reasoning strategies for various tasks.
Total factor productivity change in hog production and Quebec's revenue insurance program
Authors: Singbo Alphonse , Larue Bruno , Tamini Lota D.
Published: February 2020

Quebec's hog industry is supported by a revenue insurance program that guarantees a minimum price, but it also faces strict environmental constraints. Under price volatility, risk‐averse farms may contract their output enough to produce under increasing returns. We show that the subsidy and downside risk reduction effects of the revenue insurance program tend to stimulate output and increase the likelihood of production under increasing returns. Environmental constraints that raise the cost of manure management and limit areas under cultivation also increase the likelihood of decreasing returns. Scale efficiency and technical efficiency measures are obtained through a parametric decomposition of total factor productivity (TFP) obtained from the estimation of an output distance function. As in hog studies pertaining to other countries, we found a TFP average annual growth of 5.2% between 2004 and 2012. Scale efficiency is much lower than in other countries, as per our prior about the program's distortions and environmental constraints. Integrating annual TFP gains into the setting of the minimum guaranteed price could reduce program costs by $12 million per year. About $70–80 million per year could be saved by investing in extension activities that would bring increase the level of technical efficiency of inefficient farms to the provincial average. A metatechnology frontier approach allowing for an endogenous input was also implemented to assess the robustness of the scale efficiency results.
Positive illusions determine quality of life in drug‐resistant epilepsy
Authors: Wilson Sarah J. , Rayner Genevieve , Pieters Jessamae
Published: February 2020

Objective

Humans use a complex system of protective cognitive biases or "positive illusions" that foster emotional well‐being and subjective quality of life. This study examined the role of positive illusions in patient adjustment to drug‐resistant epilepsy and its surgical treatment.

Methods

One hundred fifty people participated, including 93 focal epilepsy patients being evaluated for surgery and 57 sociodemographically matched healthy controls. We purpose‐built computer software, "Living With Epilepsy," to assess the impact of positive illusions on patient perceptions of their current life, and administered well‐validated questionnaires of depression (Neurological Disorders Depression Inventory for Epilepsy), anxiety (Patient Health Questionnaire for Generalized Anxiety Disorder–7 items), and health‐related quality of life (HRQOL; Epilepsy Surgery Inventory–55) before and at 3 and 12 months after surgery.

Results

We identified two patient groups: those with "high positive illusions" (53%) about their epilepsy and those with "low positive illusions" (47%), with no differences between sociodemographic or epilepsy variables (all P > .05). Before epilepsy surgery, patients with high positive illusions exhibited fewer symptoms of depression (P < .001) and anxiety (P = .002) and higher HRQOL (P ≥ .002 ≤ 0.046) than those with low positive illusions. A subset of patients proceeded with surgery (n = 34 at 3 months; n = 26 at 12 months). They showed that the beneficial impact of having high positive illusions re‐emerged 12 months postsurgery, with patients reporting lower depression and anxiety (P = .006) and elevated HRQOL (P = .036) compared to low positive illusions patients, independent of seizure outcome (P > .05).

Significance

These findings point to an active psychological process in drug‐resistant patients, where approximately half generate strong positive illusions about their life with epilepsy, maintaining their mood and subjective well‐being. Those who use this psychological mechanism show better adjustment 12 months postsurgery independent of seizure outcome, providing a potential new target for psychological treatment in patients with epilepsy.
Global meta‐analysis of over 50 years of multidisciplinary and international collaborations on transmissible cancers
Authors: Dujon Antoine M. , Schofield Gail , Bramwell Georgina , Raven Nynke , Hamede Rodrigo , Thomas Frédéric , Ujvari Beata
Published: February 2020

Although transmissible cancers have, so far, only been documented in three independent animal groups, they not only impact animals that have high economic, environmental and social significance, but they are also one of the most virulent parasitic life forms. Currently known transmissible cancers traverse terrestrial and marine environments, and are predicted to be more widely distributed across animal groups; thus, the implementation of effective collaborative scientific networks is important for combating existing and emerging forms. Here, we quantify how collaborative effort on the three known transmissible cancers has advanced through the formation of collaborative networks among institutions and disciplines. These three cancers occur in bivalves (invertebrates—disseminated neoplasia; DN), Tasmanian devils (vertebrate—marsupial; devil facial tumour disease; DFTD) and dogs (vertebrate—eutherian mammal; canine transmissible venereal tumour; CTVT). Research on CTVT and DN has been conducted since 1876 and 1969, respectively, whereas systematic research on DFTD only started in 2006. Yet, collaborative effort on all three diseases is global, encompassing six major Scopus subject areas. Collaborations steadily increased between 1963 and 2006 for CTVT and DN, with similar acceleration for all three cancers since 2006. Network analyses demonstrated that scientists are organizing themselves into efficient collaborative networks; however, these networks appear to be far stronger for DFTD and DN, possibly due to the recent detection of new strains adding impetus to research and associated publications (enhancing citation trajectories). In particular, global and multidisciplinary collaborations formed almost immediately after DFTD research was initiated, leading to similar research effort and relatively greater research outputs compared to the other two diseases. Therefore, in the event of outbreaks of new lineages of existing transmissible cancers, or the discovery of new transmissible cancers in the future, the rapid formation of international collaborations spanning relevant disciplines is vital for the efficient management of these diseases.
Forecasting the future state of the economy in the United States: The role of tradable “new” risk factors
Authors: Shi Qi , Li Bin
Published: February 2020

We investigate the predictive power of several innovative tradable risk factors that have proved to be competent factors in recent asset pricing studies. Our evidence indicates that all these risk factors can predict the future state of the economy to some significant extent, and they appear to perform better in short‐horizon than in long‐horizon forecasting. Using a bootstrap simulation, our estimations of bootstrapped critical values robustly reject the criticism that our significance of statistics is overstated or understated. Such results lend support to Cochrane's argument: that a competent pricing risk factor in a plausible pricing kernel may predict the future state of economy.
The optimal use of automated office blood pressure measurement in clinical practice
Authors: Andreadis Emmanuel A. , Geladari Charalampia V. , Angelopoulos Epameinondas T.
Published: February 2020

This evidence‐based article endorses the use of automated office blood pressure (AOBP). AOBP is the most favorable office blood pressure (BP) measuring technique as it provides accurate readings with 3‐15 mm Hg lower values than the casual conventional office measurements with auscultatory or semi‐automated oscillometric devices and relates closely to awake ABP readings. The AOBP technique seems to be superior to conventional office BP in predicting hypertension‐mediated organ damage and appears to be equally reliable to awake ABP in the prediction of cardiovascular (CV) disease. AOBP readings should be obtained either unattended, with the patient alone in the examination room, or attended with the presence of personnel in the room but with no talking to the patient, although this recommendation is not frequently followed in routine clinical practice. To optimize office BP readings, the type of device, the rest period before AOBP measurements (preceding rest), and the time intervals between measurements were evaluated. As AOBP readings have the advantage of removing many confounding factors, the authors propose to perform measurements with a preceding rest in all patients at the initial visit; if AOBP readings remain <130 mm Hg in subsequent visits, measurements could be accepted, otherwise, if are higher, patients should be evaluated by out‐of‐office BP measurements.
Dental disease in alpacas. Part 2: Risk factors associated with diastemata, periodontitis, occlusal pulp exposure, wear abnormalities, and malpositioned teeth
Authors: Proost Kirsten , Pardon Bart , Pollaris Elke , Flahou Thijs , Vlaminck Lieven
Published: February 2020

Background

Dental disorders, of which tooth root abscesses are best documented, are highly prevalent in alpacas. Identification of risk factors can be valuable for prevention of dental disorders in this species.

Hypothesis/Objectives

To identify risk factors associated with wear abnormalities, malpositioning, diastemata, periodontal disease (PD), and occlusal pulp exposure at the level of the cheek teeth.

Animals

Two hundred twenty‐eight alpacas (Vicugna pacos) from 25 farms.

Methods

Cross‐sectional study. Dental examinations were performed on sedated animals. Risk factors were determined by clinical examination and interview. Multivariable logistic regression was used to identify risk factors for wear abnormalities, malpositioned teeth, diastemata, PD, and occlusal pulp exposure.

Results

Mandibular swelling was significantly associated with PD (odds ratio [OR], 11.37; 95% confidence interval [CI], 3.27‐48.81; P < .001). Nearly 73% of included animals with mandibular swelling concurrently had PD. For every increase in herd size of 1 animal, the risk for PD increased by 2% (95% CI, 1‐4%; P = .01). The association between severe stages of PD and body condition score (BCS) indicates a painful situation, impairing animal welfare (P < .001). For each 1‐day increase in interval between pasture cleanings, the odds of finding pulp exposure for a single animal was estimated to increase by 1% (95% CI, 0‐2%; P = .05).

Conclusion and Clinical Importance

Simple management tools such as measuring BCS, palpating the mandible for bony swellings, removing feces from pasture on a regular basis and decreasing herd size might help identify animals at risk for dental disorders or prevent their development.
Invited Review: The role and contribution of transcriptional enhancers in brain cancer
Authors: Arabzade A. , Stuckert A. J. , Bertrand K. C. , Mack S. C.
Published: February 2020

Genetic alterations identified across several paediatric and adult brain tumours reveal recurrent disruption of active chromatin landscapes and dysregulation of transcriptional programmes. Noncoding elements, specifically enhancers, are central to these mechanisms, and are influenced by developmental and neural gene regulatory signatures. Epigenomic and transcriptomic methods and techniques have facilitated detection of active enhancers, and characterization of brain tumours integrated with genomic structural information. These datasets have provided new insights into the mechanisms of transcriptional control that are profoundly altered in childhood and adult brain cancer; offering new ideas and molecular targets for therapeutic intervention. This review summarizes recent advances in our understanding of active transcriptional programmes of brain cancer, their impact on tumour development, and research areas for further exploration.
The alternative oxidase pathway is involved in optimizing photosynthesis inMedicago truncatulainfected byFusarium oxysporumandRhizoctonia solani
Authors: Batnini Marwa , Fernández Del‐Saz Néstor , Fullana‐Pericàs Mateu , Palma Francisco , Haddoudi Imen , Mrabet Moncef , Ribas‐Carbo Miquel , Mhadhbi Haythem
Published: February 2020

Phytopathogen infection alters primary metabolism status and plant development. The alternative oxidase (AOX) has been hypothesized to increase under pathogen attack preventing reductions, thus optimizing photosynthesis and growth. In this study, two genotypes ofMedicago truncatula, one relatively resistant (Jemalong A17) and one susceptible (TN1.11), were infected withFusarium oxysporumandRhizoctonia solani. The in vivo foliar respiratory activities of the cytochrome oxidase pathway (COP) and the alternative oxidase pathway (AOP) were measured using the oxygen isotope fractionation. Gas exchange and photosynthesis‐related parameters were measured and calculated together with antioxidant enzymes activities and organic acids contents. Our results show that the in vivo activity of AOX (valt) plays a role under fungal infection. When infected withR. solani, the increase of valtin A17 was concomitant to an increase in net assimilation, in mesophyll conductance, to an improvement in the maximum velocity of Rubisco carboxylation and to unchanged malate content. However, underF. oxysporuminfection, the induced valtwas accompanied by an enhancement in the antioxidant enzymes, superoxide dismutase (SOD; EC1.15.1.1), catalase (CAT; EC1.11.1.6) and guaiacol peroxidase (GPX; EC1.11.1.7), activities and to an unchanged tricarboxylic acid cycle intermediates. These results provide new insight into the role of the in vivo activity of AOX in coordinating primary metabolism interactions that, partly, modulate the relative resistance ofM. truncatulato diseases caused by soil‐borne pathogenic fungi.
A new HLA‐C allele, HLA‐C*07:02:83, identified in a Chinese family
Authors: Zhao Jiawei , Zhang Yan , Li Qinghua , Wei Hui , Wang Xiaojing
Published: February 2020

HLA‐C*07:02:83 differs from HLA‐C*07:02:01:01 (387C‐ > A, P105P).
Drug‐resistant organisms are common in fecal surveillance cultures, predict bacteremia and correlate with poorer outcomes in patients undergoing allogeneic stem cell transplants
Authors: Korula Anu , Perumalla Susmitha , Devasia Anup J. , Abubacker Fouzia N. , Lakshmi Kavitha M. , Abraham Aby , Mathews Vikram , Srivastava Alok , Anandan Shalini , Veeraraghavan Balaji , George Biju
Published: February 2020

Background

With the increasing incidence of multidrug‐resistant (MDR) organisms and high mortality rates associated with these infections, we describe the spectrum of the major drug‐resistant pathogens identified in fecal surveillance, and re‐visit the use of fecal surveillance in predicting infection with these organisms post‐allogeneic stem cell transplant.

Methods

Data from allogeneic stem cell transplant recipients with common drug‐resistant strains of bacteria in fecal surveillance (Escherichia coli, Klebsiella spp., and Enterococcus spp.) were compared with recipients who did not have the same in fecal surveillance cultures. Baseline characteristics and post‐transplant outcomes including similar drug resistance in blood cultures, severe sepsis, and 100‐day transplant‐related mortality were compared. Multivariate analysis using logistic regression model was used to determine independent predictors of outcome.

Results

In 232 transplants, the prevalence of common drug‐resistant isolates in fecal surveillance cultures was 57.7% (134 out of 232 patients—with a single isolate in 115 and ≥2 isolates in the remaining 19 patients. A total of 164 drug‐resistant isolates were obtained from 134 patients. Of the 164 isolates, 133 (81%) were positive for ESBL screening, 19 (11.5%) for carbapenem‐resistant organisms (CRO) screening, 12 (7.3%) for VRE screening. Patients who had common drug‐resistant pathogens detected in fecal surveillance have significantly higher subsequent blood culture positivity with drug resistance, as well as higher 100‐day mortality. Factors influencing 100‐day mortality included patient's age (P = .001), drug resistance positivity in blood (P < .001), drug resistance in fecal surveillance (P = .011), use of an alternate donor (other than fully matched sibling) (P < .001), GVHD grade 3‐4 (P < .001), and severe sepsis (P < .001). On multivariate analysis, only use of an alternate donor (0.024), severe sepsis (P < .001), and grade 3‐4 GVHD (P < .001) retained significance in predicting 100‐day mortality.

Conclusion

Organisms resistant to 3rd generation cephalosporins are frequently seen on fecal surveillance in the pre‐transplant setting and are associated with a higher incidence of drug‐resistant organisms in subsequent blood cultures (not limited to the same drug resistance pattern as seen in fecal surveillance). Drug‐resistant organisms in fecal surveillance are associated with poorer outcomes following allogeneic stem cell transplant and may be used as a guide to identify patients at risk of subsequently developing a drug‐resistant organism in blood.
Purification of canine albumin by heat denaturation in a plasma bag
Authors: Edwards Thomas H. , Koenig Amie , Thomas LeNae , Sadik Anjam , Edwards James L.
Published: February 2020

Objective

To design and evaluate a method to purify canine albumin from fresh frozen plasma (FFP) or stored plasma (SP) in a manner that could be applied clinically.

Design

In vitro experimental study.

Setting

FDA licensed Blood Bank Laboratory and University biochemistry laboratory.

Animals

None.

Interventions

Using equipment that is typically found in veterinary blood banks, plasma bags were thawed, injected with the heat stabilizing agent, sodium caprylate, and then heated and acidified to denature all but albumin proteins. Albumin‐rich supernatant was removed, the pH was neutralized, and then pasteurized and refrigerated. Albumin and total plasma protein concentrations were measured and the product was cultured for bacteria at 0, 7, 14, 30, and 60 days post‐processing.

Measurements and Main Results

Seventeen bags of plasma were analyzed for purity, yield, and sterility of the finished albumin product. Bags were divided into categories based on the age of the frozen plasma. Mean yield of albumin for all bags was 77.3% and mean purity was 91.2%. There was no difference between old stored plasma, new stored plasma, and FFP with regard to yield (P = 0.31) or purity (P = 0.24) based on one‐way analysis of variances. Overall 1 of 17 bags of plasma (5.9%) tested positive for bacterial contamination on day 60 after processing.

Conclusions

Sodium caprylate is able to stabilize canine albumin enabling it to withstand heating that denatures other plasma proteins. The resulting albumin product is of sufficient quality to potentially be used therapeutically as a colloidal resuscitative fluid. Further study is needed into its safety and effect in dogs.
Modeling Uncertain and Dynamic Interdependencies of Infrastructure Systems Using Stochastic Block Models
Authors: Yu Jin-Zhu , Baroud Hiba
Published: February 2020

Modeling the resilience of interdependent critical infrastructure (ICI) requires a careful assessment of interdependencies as these systems are becoming increasingly interconnected. The interdependent connections across ICIs are often subject to uncertainty due to the lack of relevant data. Yet, this uncertainty has not been properly characterized. This paper develops an approach to model the resilience of ICIs founded in probabilistic graphical models. The uncertainty of interdependency links between ICIs is modeled using stochastic block models (SBMs). Specifically, the approach estimates the probability of links between individual systems considered as blocks in the SBM. The proposed model employs several attributes as predictors. Two recovery strategies based on static and dynamic component importance ranking are developed and compared. The proposed approach is illustrated with a case study of the interdependent water and power networks in Shelby County, TN. Results show that the probability of interdependency links varies depending on the predictors considered in the estimation. Accounting for the uncertainty in interdependency links allows for a dynamic recovery process. A recovery strategy based on dynamically updated component importance ranking accelerates recovery, thereby improving the resilience of ICIs.
Toward an Integrated Intervention and Assessment of Robot-Based Rehabilitation
Authors: Majidirad Amirhossein , Yihun Yimesker , Cure Laila
Published: February 2020

This study presents robot-based rehabilitation and its assessment. Robotic devices have significantly been useful to help therapists do the training procedure consistently. However, as robotic devices interface with humans, quantifying the interaction and its intended outcomes is still a research challenge. In this study, human–robot interaction during rehabilitation is assessed based on measurable interaction forces and human physiological response data, and correlations are established to plan the intervention and effective limb trajectories within the intended rehabilitation and interaction forces. In this study, the Universal Robot 5 (UR5) is used to guide and support the arm of a subject over a predefined trajectory while recording muscle activities through surface electromyography (sEMG) signals using the Trigno wireless DELSYS devices. The interaction force is measured through the force sensor mounted on the robot end-effector. The force signals and the human physiological data are analyzed and classified to infer the related progress. Feature reduction and selection techniques are used to identify redundant inputs and outputs.
Neumann Boundary Control of a Linear Diffusion System Based on the Equivalent Distributed Control Model
Authors: Hamdadou Dyhia , Maidi Ahmed , Corriou Jean-Pierre
Published: February 2020

This paper deals with the boundary control of a one-dimensional diffusion system with Neumann actuation. The objective is to control a given punctual output. The control design is based on the concept of the characteristic index from geometric control theory. The idea consists of making the boundary condition homogeneous by inserting the manipulated variable into the state equation using a proposed linear transformation. Then, in order to overcome the controllability problem and to have a finite characteristic index, a weighted value of the system state, along the spatial domain, is considered as an auxiliary output. By calculating the successive derivatives of the measured output, a state feedback that enforces a set point tracking of the measured output is developed. The stability of the resulting closed-loop control system is demonstrated based on Lyapunov's method. Then, in order to meet the desired control objective of the punctual output, a control strategy is proposed based on the steady-state analysis. The tracking performance of the developed control strategy is evaluated through numerical simulation by considering the temperature control of a thin metal rod modeled by a linear heat equation.
Real-Time Implementation of Optimal Energy Management in Hybrid Electric Vehicles: Globally Optimal Control of Acceleration Events
Authors: Asher Zachary D. , Trinko David A. , Payne Joshua D. , Geller Benjamin M. , Bradley Thomas H.
Published: February 2020

Widely published research shows that significant fuel economy improvements through optimal control of a vehicle powertrain are possible if the future vehicle velocity is known and real-time optimization calculations can be performed. In this research, however, we seek to advance the field of optimal powertrain control by limiting future vehicle operation knowledge and using no real-time optimization calculations. We have realized optimal control of acceleration events (AEs) in real-time by studying optimal control trends across 384 real world drive cycles and deriving an optimal control strategy for specific acceleration event categories using dynamic programming (DP). This optimal control strategy is then applied to all other acceleration events in its category, as well as separate standard and custom drive cycles using a look-up table. Fuel economy improvements of 2% average for acceleration events and 3.9% for an independent drive cycle were observed when compared to our rigorously validated 2010 Toyota Prius model. Our conclusion is that optimal control can be implemented in real-time using standard vehicle controllers assuming extremely limited information about future vehicle operation is known such as an approximate starting and ending velocity for an acceleration event.
Impact of Wall Waviness on the Convection Patterns Inside a Horizontal Porous Annulus
Authors: Belabid Jabrane
Published: February 2020

A numerical simulation of natural convection in a horizontal porous annulus with an internal wavy surface has been carried out. Governing equations include the heat equation and the hydrodynamics equations under Darcy law and Boussinesq approximation. The mathematical model formulated with the temperature-stream function is solved numerically using the finite difference method with the alternating direction implicit scheme. Results show that the heat transfer and the convective instability depend strongly on the waviness of the inner cylinder. Last, streamlines and isotherms are presented for different waviness parameters of the internal wall for better understanding of the influence of amplitude and number of undulations on the thermo-convective instabilities.
Digital Sequence and Virtual Path Construction-Based Impact Imaging Method for Onboard Monitoring of Aerospace Composite Structures
Authors: Ren Yuanqiang , Qiu Lei , Yuan Shenfang , Lin Xiaodong
Published: February 2020

Because of the rapidly growing use and poor impact resistance of composite materials, impact monitoring of composite structures has become more and more important, especially for aerospace engineering applications. Among the existing impact monitoring methods, piezoelectric transducer (PZT) network and guided wave-based imaging method has proved to be an effective structural health monitoring (SHM) technology. However, the pursuit of accurate localization of ordinary impact imaging methods comes at a cost, the high requirement for the SHM hardware system making these methods inapplicable for onboard impact monitoring. In order to realize accurate impact monitoring of aerospace composite structures onboard, this paper proposes a digital sequence and virtual path construction-based impact imaging method, which is simple enough to work in a digital impact monitor with a greatly simplified hardware system. The monitor is used to convert the impact response signals of PZTs into digital sequences, based on which the method first recognizes the impact occurring sub-region. Then, the virtual pitch–catch paths of the recognized sub-region are innovatively defined and constructed to estimate the impact-induced influence on these paths so that the path-synthesis imaging algorithm-based impact imaging can be performed with little computation cost. To verify the feasibility and effectiveness of the proposed method, a total of 90 impacts are applied on a composite unmanned aerial vehicle (UAV) wing, and experimental results show the good performance of accurate impact imaging and localization.
Dynamic Response of Fractionally Damped Viscoelastic Plates Subjected to a Moving Point Load
Authors: Praharaj Rajendra Kumar , Datta Nabanita , Sunny Mohammed Rabius
Published: February 2020

The dynamic response of fractionally damped viscoelastic plates subjected to a moving point load is investigated. In order to capture the viscoelastic dynamic behavior more accurately, the material is modeled using the fractionally damped Kelvin–Voigt model (rather than the integer-type viscoelastic model). The Riemann–Liouville fractional derivative of order 0 < α ≤ 1 is applied. Galerkin's method and Newton–Raphson technique are used to evaluate the natural frequencies and corresponding damping coefficients. The structure is subject to a moving point load, traveling at different speeds. The modal summation technique is applied to generate the dynamic response of the plate. The influence of the order of the fractional derivative on the free and transient vibrations is studied for different velocities of the moving load. The results are compared with those using the classical integer-type Kelvin–Voigt viscoelastic model. The results show that an increase in the order of the fractional derivative causes a significant decrease in the maximum dynamic amplification factor, especially in the “dynamic zone” of the normalized sweep time. The dynamic behavior of the plate is verified with ansys.
Performance of Public Film Cooling Geometries Produced Through Additive Manufacturing
Authors: Snyder Jacob C. , Thole Karen A.
Published: February 2020

Film cooling is an essential cooling technology to allow modern gas turbines to operate at high temperatures. For years, researchers in this community have worked to improve the effectiveness of film cooling configurations by maximizing the coolant coverage and minimizing the heat flux from the hot gas into the part. Working toward this goal has generated many promising film cooling concepts with unique shapes and configurations. However, until recently, many of these designs were challenging to manufacture in actual turbine hardware due to limitations with legacy manufacturing methods. Now, with the advances in additive manufacturing, it is possible to create turbine parts using high-temperature nickel alloys that feature detailed and unique geometry features. Armed with this new manufacturing power, this study aims to build and test the promising designs from the public literature that were previously difficult or impossible to implement. In this study, different cooling hole designs were manufactured in test coupons using a laser powder bed fusion process. Each nickel alloy coupon featured a single row of engine scale cooling holes, fed by a microchannel. To evaluate performance, the overall cooling effectiveness of each coupon was measured using a matched Biot test at engine relevant conditions. The results showed that certain hole shapes are better suited for additive manufacturing than others and that the manufacturing process can cause significant deviations from the performance reported in the literature.
Effect of 45-deg Rib Orientations on Heat Transfer in a Rotating Two-Pass Channel With Aspect Ratio from 4:1 to 2:1
Authors: Sahin Izzet , Chen Andrew F , Shiau Chao-Cheng , Han Je-Chin , Krewinkel Robert
Published: February 2020

The internal cooling passages of gas turbine blades mostly have varying aspect ratios from one passage to another. However, there are limited data available in the open literature that used a reduced cross section and aspect ratio (AR), after the tip turn. Therefore, the current study presents heat transfer and pressure drop of three different α = 45 deg profiled rib orientations, typical parallel (usual), reversed parallel (unusual), and crisscross patterns in a rotating two-pass rectangular channel with AR = 4:1 and 2:1 in the first radially outward flow and second radially inward flow passages, respectively. For each rib orientation, regional averaged heat transfer results are obtained for both the flow passages with the Reynolds number ranging from 10,000 to 70,000 for the first passage and 16,000 to 114,000 for the second passage with a rotational speed range of 0–400 rpm. This results in the highest rotation number of 0.39 and 0.16 for the first and second passage respectively. The effects of rib orientation, aspect ratio variation, 180-deg tip turn, and rotation number on the heat transfer and pressure drop will be addressed. According to the results, for usual, unusual and crisscross rib patterns, increasing rotation number causes the heat transfer to decrease on the leading surface and increase on the trailing surface for the first passage and vice versa for the second passage. The overall heat transfer enhancement of the usual and unusual rib patterns is higher than the crisscross one. In terms of the pressure losses, the crisscross rib pattern has the lowest and the usual rib pattern has the highest-pressure loss coefficients. When pressure loss and heat transfer enhancement are both taken into account together, the crisscross or unusual rib pattern might be an option to use in the internal cooling method. Therefore, the results can be useful for the turbine blade internal cooling design and heat transfer analysis.
Evaluation of Turbulent Spot Production Rate in Boundary Layers Under Variable Pressure Gradients for Gas Turbine Applications
Authors: Dellacasagrande M. , Lengani D. , Simoni D. , Ubaldi M. , Zunino P.
Published: February 2020

The paper presents several results from an experimental data base on transitional boundary layers developing on a flat plate installed within a variable area opening endwall channel. Measurements have been carried out by means of time-resolved particle image velocimetry (PIV). The overall test matrix spans three Reynolds numbers, four freestream turbulence intensity levels, and four different flow pressure gradients. For each condition, 16,000 instantaneous flow fields have been acquired in order to obtain high statistical accuracy. The flow parameters have been varied in order to provide a gradual shift of the mode of transition from a by-pass process to separated flow transition. In order to quantify the influence of the flow parameter variation on the boundary layer transition process, the transition onset and end positions, and the turbulent spot production rate have been evaluated with a wavelet-based intermittency detection technique for every condition exhibiting a complete transition process. The by-pass transition mode has the longest transition length that decreases with increasing the Reynolds number. The transition length of the separated flow case is smaller than the by-pass one, and the variation of the flow parameters has a similar impact. The variation of the inlet turbulence intensity has a small influence on this parameter except for the condition at the highest turbulence intensity that always shows the lowest turbulent spot production rate because a by-pass type transition occurs. This large amount of data has been used to develop new correlations used to predict the spot production rate and the transition length in attached and separated flows.
Ligament and Bone Arch Partition of the Carpal Tunnel by Three-Dimensional Ultrasonography
Authors: Shah Rakshit , Li Zong-Ming
Published: February 2020

The carpal tunnel is geometrically irregular due to the complex composition of many carpal bones intercalated by numerous intercarpal ligaments. The purpose of the study was to investigate the relative contributions of the ligament and bone arches to carpal tunnel space at the proximal, middle, and distal tunnel regions. A catheter ultrasound probe acquired fan-like images inside cadaveric carpal tunnels for three-dimensional reconstruction of the tunnel. The total tunnel volume was 5367.6 ± 940.1 mm3 with contributions of 12.0%, 6.9%, and 4.1% by proximal, middle, and distal ligament arches, respectively, and 27.0%, 25.3%, and 24.7% by proximal, middle, and distal bone arches, respectively. The bone arch occupied more tunnel space than the ligament arch at all regions (p < 0.05). The ligament arch was largest at the proximal region of the tunnel and significantly decreased toward the distal region (p < 0.05). However, the bone arch significantly decreased only from the proximal to middle region (p < 0.05) but not from the middle to distal region (p = 0.311). Consequently, it was observed that the ligament arch was the key contributor to the unequal carpal tunnel space across regions. Partitional and regional tunnel morphometric information may provide a better understanding of tunnel abnormality associated with various wrist pathological conditions. The developed framework of ultrasonography and data processing can be applied to other areas of interest in the musculoskeletal system.
Additive Manufacturing Distortion Compensation Based on Scan Data of Built Geometry
Authors: McConaha Matthew , Anand Sam
Published: February 2020

Additive manufacturing (AM) processes such as direct metal laser sintering (DMLS) are highly attractive manufacturing processes due to the ability to create certain geometries which would be prohibitive or even impossible to manufacture by other means. However, with such high thermal gradients which are usually present in these processes, manufacturing distortions may result in the creation of unacceptable parts. This paper presents an approach to compensate input STL files based on registration of the point cloud from sacrificial part builds. A novel strain energy based non-rigid registration algorithm has been developed for robust registration of data points to the original computer-aided design (CAD) model. A neural network based approach is used to learn the deformation of the geometry based on the deviation of the scan geometry. This network is subsequently used to modify the STL file to generate a new compensated STL file. The compensated STL file was validated by building parts and comparing the change in the part distortion.
A Dynamic Modeling Methodology to Estimate the Magnitude of Unwanted Liquid Flows in High Temperature Boiler Components
Authors: de Klerk Gary , Rousseau Pieter , Jestin Louis
Published: February 2020

Due to the penetration of variable renewable energy (VRE) sources into electricity supply grids, conventional coal fired power plants need to operate with greater flexibility while remaining reliable and conserving the lifetime of components. Thick-sectioned components are prone to thermal fatigue cracking as a result of through-wall temperature gradients. These temperature gradients can be significantly amplified during quenching when components at high temperature are unintentionally exposed to colder liquid or steam. Such quench events are known to occur during two-shift operation of a large once-through coal fired tower type boiler. The purpose of this study is to develop and demonstrate a model that can be used to determine the root cause and magnitude of quenching. The model is developed using the least level of detail to make it readily usable by power plant engineers. Two different approaches are used. A liquid tracking model (LTM) was developed from first principles that approximates the liquid level in the superheater as a function of time. The model is presented and verified by comparison with real-plant data. The second approach was to configure a model in flownex, which is a commercially available software package. The LTM model with eight control volumes provided better steam temperature results and was able to simulate the correct superheater pressure behavior without solving the momentum equation. The models proved that a separator overflow was the cause of quenching for this particular case study.
Mild Whole-Body Hyperthermia-Induced Interstitial Fluid Pressure Reduction and Enhanced Nanoparticle Delivery to PC3 Tumors: In Vivo Studies and Micro-Computed Tomography Analyses
Authors: Gu Qimei , Liu Shuaishuai , Saha Ray Arunendra , Florinas Stelios , Christie Ronald James , Daniel Marie-Christine , Bieberich Charles , Ma Ronghui , Zhu Liang
Published: February 2020

In this study, we performed in vivo experiments on mice to evaluate whether whole-body hyperthermia enhances nanoparticle delivery to PC3 (prostatic cancer) tumors. PC3 xenograft tumors in immunodeficient mice were used in this study. The mice in the experimental group were subjected to whole-body hyperthermia by maintaining their body temperatures at 39–40 °C for 1 h. Interstitial fluid pressures (IFPs) in tumors were measured before heating, immediately after, and at 2 and 24 h postheating in both the experimental group and in a control group (without heating). A total of 0.2 ml of a newly developed nanofluid containing gold nanoparticles (AuNPs) was delivered via the tail vein in both groups. The micro-computed tomography (microCT) scanned images of the resected tumors were analyzed to visualize the nanoparticle distribution in the tumors and to quantify the total amount of nanoparticles delivered to the tumors. Statistically significant IFP reductions of 45% right after heating, 47% 2 h after heating, and 52% 24 h after heating were observed in the experimental group. Analyses of microCT scans of the resected tumors illustrated that nanoparticles were more concentrated near the tumor periphery rather than at the tumor center. The 1-h whole-body hyperthermia treatment resulted in more nanoparticles present in the tumor central region than that in the control group. The mass index calculated from the microCT scans suggested overall 42% more nanoparticle delivery in the experimental group than that in the control group. We conclude that 1-h mild whole-body hyperthermia leads to sustained reduction in tumoral IFPs and significantly increases the total amount of targeted gold nanoparticle deposition in PC3 tumors. The present study suggests that mild whole-body hyperthermia is a promising approach for enhancing targeted drug delivery to tumors.
Energy Usage Intensity of Bank Building Stock: A Case Study in Pakistan
Authors: Amber Khuram Pervez , Aslam Muhammad Waqar , Kousar Anila , Khan Muhammad Sajid , Chaudhary Ghulam Qadir , Amar Muhammad
Published: February 2020

Energy usage intensity (EUI, kWh/m2/year) of a building category helps energy managers and building owners in evaluating the energy performance of their buildings. Banks are energy-intensive buildings, but there is limited research published in this highly energy-intensive building category. In this paper, the energy consumption of 98 bank buildings located in different cities of the AJK region of Pakistan has been critically analyzed and their EUI value has been established. Data were collected through site visits, interviews, and questionnaires. Electricity consumption of each bank branch was normalized using the cooling degree days method and respective annual normalized EUIs were calculated. It was found through analysis that three major factors that drive electricity consumption in bank buildings in Pakistan are building's area, the number of workstations, and the number of automatic teller machines. The EUI of banks in Pakistan has been found to be 222 kWh/m2/yr, which is comparable with the same of eight other countries.