bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of longitudinal and radial characteristics of intra‐anal pressures using 3D high‐definition anorectal manometry between children with anoretal malformations and functional constipation
Authors: Ambartsumyan Lusine , Shaffer Michele , Carlin Kristen , Nurko Samuel
Published: September 2020

Background

Pathophysiology of fecal incontinence (FI) in children with anorectal malformations (AM) is not well understood. Standard or high‐resolution anorectal manometry (ARM) does not identify radial asymmetry or localize abnormal sphincter function. 3D high‐definition anorectal manometry (HDARM) provides detailed topographic and 3D pressure gradient representation of anal canal.

Aims

To compare intra‐anal pressure profiles between children with AM and controls using HDARM and to determine the association between manometric properties and reported predictors of fecal continence (AM type, spinal anomaly, and sacral integrity).

Methods

HDARM tracings of 30 children with AM and FI referred for ARM were compared with 30 age and sex‐matched children with constipation. 2D pressure profiles were used to measure length of high‐pressure zone (HPZ). Longitudinal and radial measurements of sphincter pressure at rest and squeeze were taken along each segment in 3D topographic views and compared between groups.

Key Results

3D measurements demonstrated longitudinal and radial differences between groups along all quadrants of HPZ. At rest, intra‐anal pressures were lower along the four segments longitudinally across the anal canal and radially along the quadrants in AM group (P < .01). At squeeze, all quadrant pressures were lower in segments 1‐4 in AM group (P < .01). Sensation was abnormal in AM group (P < .01). Intra‐anal pressures longitudinally and radially were not associated with predictors of fecal continence.

Conclusions and Inferences

Children with AM had abnormal sensation and lower pressures longitudinally and radially along all quadrants of anal canal. Manometric properties at rest were not associated with reported predictors of fecal continence.
The theory of caritative caring: Katie Eriksson’s theory of caritative caring presented from a human science point of view
Authors: Näsman Yvonne
Published: September 2020

The Finnish nursing theorist Katie Eriksson's (1943–2019) theory of caritative caring represents a non‐medical paradigm concerning the phenomena of nursing. The aim of this article was to present an oversight of the development of Eriksson's theory of caritative caring from a human science point of view. The historical development of the theory is outlined, combined with a brief overview of its philosophical connections, its impact on contemporary caring science research and its implications for nursing care. Caring science is considered a human science in the Nordic tradition, as it is deeply rooted in basic issues of human life and existence. The key ideas of Eriksson's theory of caritative caring are linked to the metaparadigm concepts of human being, health and suffering, caring and environment. All of these are permeated with the ethos of caritative caring, that is, the caritas thought of human love and mercy, and the honouring of the absolute dignity of human beings. Epistemologically, Gadamer is the most influential philosopher when it comes to the theory of caritative caring. Eriksson's theory is used in, for example, intercultural caring, caring for patients suffering from addiction, the importance of aesthetic surroundings, providing ethically good care for older people and mothers as patients in psychiatric care. In these fields of research, Eriksson's ideas of ethics, caring and suffering are highlighted in various clinical contexts. Beyond the areas of nursing care in which Eriksson's work has been cited and developed, there are at least two areas that have been actively enhanced by her works: the field of leadership and education for nursing teachers. According to Eriksson, it is momentous to ponder scientific results as not limited to empirically strengthened, randomized outcomes. Part of making the results of scientific work evident is up to the individual nurses and their being in the world.
Anatomic Restoration of Triple Disruption of the Superior Shoulder Suspensory Complex: A Case Report and Review of the Literature
Authors: Wu Kai , Wu Xiao‐ming , Zha Xiao‐long , Wang Qiu‐gen
Published: September 2020

Background

Multiple disruptions of the superior shoulder suspensory complex (SSSC) involving more than two components are extremely rare. In some extreme situations, three components of the SSSC structure can be involved. The ideal treatment for this type of injury is debatable.

Case presentation

A 21‐year‐old woman was referred to our emergency center following a traffic accident. A three‐dimensional CT scan showed triple disruption of the SSSC involving concomitant ipsilateral fractures of the coracoid, the acromion, and the distal clavicle. The connection between the upper limber and the axial skeleton was destroyed. There was no evidence of associated injury and the neurovascular examination of the injured upper limb was normal. The patient underwent an open reduction and internal fixation to restore the anatomic integrity of the SSSC. The arm was supported in a broad arm sling for 2 weeks after surgery. Gentle passive range of motion activity under analgesic was encouraged from the second day postoperatively. One year and half after the operation, the patient had regained pain free and unrestricted shoulder stability and mobility.

Conclusion

The manifestations of multiple disruptions of the SSSC may be variable. This case illustrated the challenges of treating the multiple disruption of the SSSC structure. It also showed that surgical intervention for this rare combination injury yields an excellent functional result. The good outcome achieved in this patient demonstrates that surgical intervention might be an optional resolution for multiple disruptions of the SSSC.
Radiofrequency catheter ablation of premature ventricular contractions from the mitral annulus in patients without structural heart disease
Authors: Antoku Yoshibumi , Takemoto Masao , Tanaka Atsushi , Mito Takahiro , Masumoto Akihiro , Ueno Takafumi , Tsuchihashi Takuya
Published: September 2020

Introduction

We previously reported the clinical benefits of radiofrequency catheter ablation (RFCA) of premature ventricular contractions (PVCs) from the right ventricular outflow tract or near the His‐bundle, which can often deteriorate the clinical status. PVCs from the mitral valve (MA‐PVCs) also often deteriorate the patients’ clinical status. This study aimed to evaluate the effect of ablating MA‐PVCs with RFCA from a trans‐interatrial septal approach on the clinical status in symptomatic patients with frequent MA‐PVCs without structural heart disease.

Methods

The frequency of PVCs per the total heart beats by 24‐hours Holter monitoring and New York Heart Association (NYHA) functional class in 22 patients with MA‐PVCs were evaluated before and 6 months after RFCA.

Results

Procedural success was achieved in 20 (91%) of 22 patients. Of the 22 patients, in 15 (68%) and 1 (5%) patient, a successful RFCA on the left ventricular side of the MA using the trans‐interatrial septal approach and trans‐coronary sinus approach was achieved. Interestingly, in four (18%) patients, a successful RFCA on the left atrial (LA) side of the MA using a trans‐interatrial septal approach was achieved. Ablating MA‐PVCs readily improved the NYHA functional class compared to that before. A ≥0.62 peak deflection index and ≤30 years old may be one of the important predictors of successfully ablated MA‐PVCs from the LA side of the MA.

Conclusions

RFCA produces clinical benefits in patients with MA‐PVCs. Further, it may be necessary to initially consider a trans‐interatrial septal approach to ablate these PVCs.
Making nice or faking nice? Exploring supervisors’ two‐faced response to their past abusive behavior
Authors: McClean Shawn T. , Courtright Stephen H. , Yim Junhyok , Smith Troy A.
Published: September 2020

Although extant research has shown that abusive supervision is a destructive and immoral form of leader behavior, theory provides conflicting perspectives on how supervisors respond to their own abusive behavior. We therefore draw upon and integrate moral cleansing theory and impression management and construction theory to explore whether and when supervisors engage in genuine reparations or impression management following episodes of abusive behavior. Results taken from a 3‐week, experience sampling study of supervisors suggest support for the impression management path; following episodes of abusive behavior, supervisors higher on symbolized moral identity become more concerned with their image, and thus engage in increased ingratiation, self‐promotion, and exemplification toward their subordinates. In contrast, we found no support for the genuine, moral cleansing path. This study thus extends knowledge regarding supervisors’ responses to their own abusive behavior, challenging the existing notion that such responses are genuine and focused on addressing the moral implications of the behavior.
Navigating relational turbulence in the wake of weight loss transitions: A support marshaling analysis
Authors: Crowley John P. , Burke Tricia , Denes Amanda , Allred Ryan , Carberry Emmalene
Published: September 2020

The current study sought to investigate how individuals optimize their partner's support during a weight transition to accomplish their weight loss goals. A theoretical model was tested to determine the role of support marshaling in managing the relational turbulence associated with weight transitions. Path modeling broadly identified that support marshaling is a useful framework from which to consider how relational turbulence associated with weight transitions influences health behaviors. The results identify that partner facilitation and interference are both directly related to health behaviors and indirectly related to health behaviors through support marshaling. Theoretical implications for relational turbulence and support marshaling are discussed with regard to their ability to account for weight‐related behavior changes.
Scent chemistry and pollinators in the holoparasitic plant Cynomorium songaricum (Cynomoriaceae)
Authors: Wang D. , Yu H. , Chen G.
Published: September 2020

Holoparasitic plants are interesting heterotrophic angiosperms. However, carrion‐ or faeces‐mimicking is rarely described for such plants. There is no information on the pollination biology of Cynomoriaceae, despite the fact that these plants are rare and vulnerable. This is the first study to reveal pollination in a member of this family, Cynomorium songaricum, a root holoparasite with a distinctive and putrid floral odour.

From 2016 to 2018, we studied the floral volatiles, floral visitors and pollinators, behavioural responses of visitors to floral volatiles, breeding system, flowering phenology and floral biology of two wild populations of C. songaricum in Alxa, Inner Mongolia, China.

A total of 42 volatiles were identified in inflorescences of C. songaricum. Among these volatiles are compounds known as typical carrion scents, such as p‐cresol, indole, dimethyl disulphide and 1‐octen‐3‐ol. C. songaricum is pollinated by various Diptera, such as Musca domestica, M. stabulans (Muscidae), Delia setigera, D. platura (Anthomyiidae), Lucilia sericata, L. caesar (Calliphoridae), Wohlfahrtia indigens, Sarcophaga noverca, S. crassipalpis and Sarcophila meridionalis (Sarcophagidae). The inflorescence scent of C. songaricum attracted these pollinators. The plants significantly benefit from insect pollination, although wind can be a pollen vector in the absence of pollinators. C. songaricum is a cross‐pollinated, self‐incompatible plant.

Our findings suggest that C. songaricum releases malodorous volatiles to attract Diptera to achieve pollination. This new example lays the foundation for further comparative studies in other members of this plant group and contributes to a better understanding of fly‐pollinated, carrion mimicking plants.
Aquatic invertebrate assemblages as potential indicators of restoration conditions in wetlands of Northeastern China
Authors: Lu Kangle , Wu Haitao , Guan Qiang , Lu Xianguo
Published: September 2020

Wetland restoration has been implemented widely but evaluation of the effectiveness of wetland restoration has been limited. In this study, we aimed to investigate the utility of aquatic invertebrate assemblages as potential indicators of restoration condition in wetlands of the Sanjiang Plain, Northeastern China. Results from non‐metric multidimensional scaling analysis of invertebrate assemblages showed that study wetlands (n = 16) divided into two groups: natural wetlands and wetlands that have been restored for 4 years were classified as a group, and impaired wetlands and wetlands restored for only 1 year were classified into another group. After 4 years of recovery, 47.9% of invertebrate taxa found at the natural wetlands could also be found at the restored wetlands, primarily insects with aerial dispersal capabilities for rapid colonization. Indicator species analysis identified differences in community composition among wetland types, and Amphiagrion sp. and Bezzia sp. were indicators of the restored wetlands. In Northeastern China, aquatic invertebrate assemblages and certain indicator species may provide robust measures of wetland restoration. It is urgent for further exploration to monitor restored wetlands in the long‐time series and fully assess the efficiency of the restoration.
Accountability in transnational governance: The partial organization of voluntary sustainability standards in long‐term account‐giving
Authors: Arnold Nadine
Published: September 2020

Transnational sustainability governance often builds upon standards. Considering that the rise of transnational governance has blurred accountability relations, this article interrogates how and with what consequences a standards development organization (SDO) mobilizes standards for the sake of accountability. Following a partial organization perspective, standards are conceptualized as combinations of organizational elements that enhance accountability both retrospectively and prospectively. A historical case study of the Fairtrade program details the argument and shows how the SDO modified standards aligned with institutional expectations. As the alteration of one organizational element led to a chain reaction, the standards unintentionally transformed from an organizationally lenient tool into a sophisticated blend of organizational elements. Thus, the standards strengthened the accountability of those being governed, while accountability to the public was enhanced by changes in the organizational structure of the SDO. The article contributes to a nuanced understanding of the link between accountability and standards, highlighting their contingency and context dependency.
A Queer Sociology: On Power, Race, and Decentering Whiteness
Authors: Moussawi Ghassan , Vidal‐Ortiz Salvador
Published: September 2020

In this article, we argue for “a queer sociology” that centers race and processes of racialization, while naming and decentering Whiteness. “A queer sociology” is a field that foregrounds relations of power, particularly: race, class, empire, gender and gender identity, and sexuality, and that does not use queer in a reductionist way (or merely in reference to LGBT identity‐based projects). We question the uses of queer theory in sociology and show how previous iterations miss/ignore multiple genealogies of the field, like Black feminist thought, women of color feminisms, and the queer of color critique. “A queer sociology” centers power relations beyond gender and sexuality, recognizing the invisible and overarching work of Whiteness and the US (as unnamed centers of analyses) in structuring not only the sociology of sexualities, but sociological thinking overall. We invite sociology to engage with our theorization of “a queer sociology” as a way to transform our categories of analysis and how we conceive of power.
Community‐engaged sustainable health care education
Authors: Teherani Arianne , Nikjoo Arya , den Boer Alanya , Tong Michelle Sun , Desai Anya
Published: September 2020

Background

Climate and ecological changes substantially impact human health. Sustainable health care education (SHE) teaches health professions students about the interdependence of ecosystems and human health, the health sector's impact on the environment, and sustainable solutions for both ecosystems and human health. Yet little is understood about the methods used to facilitate SHE learning within the local context. Community‐engaged medical education (CEME), a concept used in medicine and other health professions, underscores the relationship between the community served and education, which is both interdependent and reciprocal. Our objective was to characterise how SHE could be made relevant to the local context and the health of the community.

Methods

Qualitative content analysis was used to explore the perspectives of faculty members, community experts and health professions students on the relationship between SHE and CEME. Semi‐structured interviews were conducted with 51 participants between March 2016 and May 2017.

Results

Participants highlighted that it was vital for students to become familiar with real‐world, locally relevant issues by collaborating with community members and identifying opportunities for engagement. For optimal learning, CEME experiences should be accompanied by relevant curricular changes. Educational partnerships with local organisations, societies and activists provide continuing opportunities for dialogue about, and integration of, SHE.

Discussion

The integration of SHE through CEME will draw the community voice into the curriculum and will compel students to connect CEME SHE learning to their continuing education. The credible and respected role of the health professionals and health professions institutions provide a foundation for the development of community partnerships and the promotion of SHE.

The integration of SHE through CEME will draw the community voice into the curriculum and will compel students to connect CEME SHE learning to their continuing education
Successful cord blood transplantation for myelodysplastic syndrome complicated by Mycobacterium kansasii pneumonia
Authors: Yamada Arisa , Akahane Daigo , Katagiri Seiichiro , Yoshizawa Seiichiro , Furuya Nahoko , Fujimoto Hiroaki , Gotoh Moritaka , Gotoh Akihiko
Published: September 2020

Non‐tuberculous mycobacterial (NTM) disease is a rare cause of neutropenic fever in patients with hematological malignancies. There are few studies on the optimal management for such patients with NTM. We report a case of myelodysplastic syndrome (MDS) treated by umbilical cord blood transplantation (CBT) after Mycobacterium kansasii (M kansasii) pneumonia. A 38‐year‐old man diagnosed with MDS developed severe pneumonia during induction chemotherapy. Repeated sputum culture uncovered mycobacterium infection. Then, by the polymerase chain reaction of the bronchial lavage fluid, M kansasii infection was proven. After 140 days of anti‐NTM therapy, CBT was successfully carried out and the patient recovered without recurrence of NTM infection. This case provides valuable evidence that hematopoietic stem cell transplantation is feasible after a reliable diagnosis and continuous anti‐NTM therapy.
Surgical treatment and outcome of complete unilateral urinary tract duplication in a dog
Authors: Sprocatti Mara , Reese David , Charlesworth Tim
Published: September 2020

Objective

To report the surgical technique and outcome for correction of complete unilateral duplication of the left urinary tract in a dog.

Animals

One 7‐month‐old entire male Jack Russell terrier.

Study design

Case report

Methods

A dog was referred for investigation because of urinary incontinence (UI), preputial irritation (pruritus), diphallia, and cryptorchidism. Computed tomography including urethrographic studies revealed a left duplex kidney, double ectopic left ureters, and a duplex urinary bladder comprising two halves separated by a median septum, each of which emptied into a separate urethra which coursed through separate penises. The left testis was abdominally retained. The right upper urinary tract was considered normal, and the right testis was within the scrotum. Left sided ureteronephrectomy was performed, the median bladder septum was ablated, and the left urethra was ligated. The left penis was partially amputated, and the dog was castrated.

Results

Urinary incontinence was improved but persisted after surgery. After repeat imaging, revision surgery was performed 3 months later in which the distal stumps of the (left) ectopic ureters were found to be filling with urine from the right urethra. Urinary incontinence resolved after resection of these ureteric stumps from the prostate and complete transection of the left urethra.

Conclusion

Extensive surgery with resection and correction of urinary tract duplication was successful in resolving UI in this case. Urogenital duplication should be considered a rare cause of UI. The presence of external congenital deformity (eg, diphallia) should alert clinicians to the possibility of significant concurrent internal abnormalities.
Thermal Comfort and Energy Savings in a Simulated Office Conditioned by a Transient Personalized Ventilator and a Displacement Ventilation System
Authors: Al Assad Douaa , Ghali Kamel , Ghaddar Nesreen , Katramiz Elvire
Published: September 2020

The aim of this work is to evaluate the performance of an intermittent personalized ventilation (IPV) system assisting a displacement ventilation (DV) system to improve thermal comfort and save energy. This will be conducted by developing a transient 3D computational fluid dynamics (CFD) model of an occupied office space equipped with systems. The occupant is modeled by a heated thermal manikin replicating the human body. The CFD model is coupled with a transient bio-heat model to compute segmental skin temperatures and their rate of change. The latter are taken as input into Zhang’s comfort model to predict and overall thermal comfort.

The model was used to conduct a case study, where the overall thermal comfort and energy savings will be assessed for the IPV + DV These results will be compared with those of steady personalized ventilation (PV) + DV and standalone DV systems. By varying the IPV frequency in the typical indoor range of [0.3 Hz – 1 Hz], it was found that the IPV + DV system was able to enhance comfort compared to steady PV + DV and a standalone DV. In addition, an energy analysis was conducted and it was shown that the IPV was able to achieve considerable energy savings compared to a steady PV + DV at the same thermal comfort level. Moreover, relaxing the DV supply temperature to higher occupied zone temperatures, can provide additional energy savings while still maintaining comfort levels in the space.
A Thermally Actuated Microvalve for Irrigation in Precision Agriculture Applications
Authors: Bamido Alaba , Thyagarajan Ashok , Shettigar Nandan , Banerjee Debjyoti
Published: September 2020

It is currently impossible to control irrigation at the level of a single plant. Even with drip irrigation, in which emitters could conceivably be placed on a plant-by-plant basis, there is no way to control the amount of water emitted according to the needs of the individual plants. If such a capability were practically available on farms, the result would be a step change in precision agriculture, such that the water input for every plant in a farm (or field) could be optimized. Therefore, we are exploring the possibility of developing a microfluidic system that could be controlled, capillary by capillary, to deliver the needed amount of water to individual plants in a large field. The principal aim is to show proof of concept by building and testing a prototype to produce data suggestive of the potential for multiple individually controllable microfluidic ports along a pressurized tube of water. Hence, in this study we perform experiments using a thermally actuated microvalve for irrigation in precision agriculture applications. The microvalve was manufactured using soft-lithography techniques, i.e., using polydimethylsiloxane (PDMS). The active microvalve was designed for a “normally open” configuration and consists of two layers: (1) a flow layer and (2) a control layer. The flow layer contains the water inlet, outlet, and the flow channels for passage of water. The control layer contains an enclosure (chamber) which expands upon heating, which in turn deforms a thin membrane into the flow layer and thus impedes (or reduces) the water flow rate in the flow layer. Both layers are bonded together and then on a glass substrate. The bonded PDMS microvalve and glass assembly is heated to different temperatures for enabling the actuation of the microvalve. Experiments were performed using two microvalves of identical design but with two different actuation fluids. The first design used the control chamber filled the air while the second design used the control chamber containing a Phase Change Material (PCM). Experiments were performed to determine the reduction of water flowrate as the membrane deforms with increase in temperature. Water flows into the inlet of the microvalve from a syringe barrel, with a hydrostatic pressure head of about 0.62 [m]. The water from the microvalve outlet was collected in a 10[ml] pipette. The results show that the water flowrate decreased as the temperature at the base of the microvalve was increased. There was a 60% and 40% reduction in the water flowrate through the microvalve design with control chamber containing air and PCM (phase change material) respectively.
Verification of ANSYS and Matlab Conduction Results Using Analytical Solutions
Authors: McMasters Robert L. , de Monte Filippo , D'Alessandro Giampaolo , Beck James V.
Published: September 2020

A two-dimensional transient thermal conduction problem is examined and numerical solutions to the problem generated by ANSYS and Matlab, employing the finite element method, are compared against an analytical solution. Various different grid densities and time-step combinations are used in the numerical solutions, including some as recommended by default in the ANSYS software, including coarse, medium and fine spatial grids. The transient temperature solutions from the analytical and numerical schemes are compared at four specific locations on the body and time-dependent error curves are generated for each point. Additionally, tabular values of each solution are presented for a more detailed comparison.

The errors found in the numerical solutions by comparing them directly with the analytical solution vary depending primarily on the time step size used. The errors are much larger if calculated using the analytical solution at a given time as a basis of the comparison between the two solutions as opposed to using the steady-state temperature as a basis. The largest errors appear in the early time steps of the problem, which is typically the regime wherein the largest errors occur in mathematical solutions to transient conduction problems. Conversely, errors at larger values of dimensionless time are extremely small and the numerical solutions agree within one tenth of one percent of the analytical solutions at even the worst locations.

In addition to difficulties during the early time values of the problem, temperatures calculated on convective boundaries or prescribed-heat-flux boundaries are locations generating larger-magnitude errors. Corners are particularly difficult locations and require finer gridding and finer time steps in order to generate a very precise solution from a numerical code. These regions are compared, using several grid densities, against the analytical solutions. The analytical solutions are, in turn, intrinsically verified to eight significant digits by comparing similar analytical solutions against one another at very small values of dimensionless time. The solution developed using the Matlab differential equation solver was found to have errors of a similar magnitude to those generated using ANSYS.

Two different test cases are examined for the various numerical solutions using the selected grid densities. The first case involves steady heating on a portion of one surface for a long duration, up to a dimensionless time of 30. The second test case involves constant heating for a dimensionless time of one, immediately followed by an insulated condition on that same surface for another duration of one dimensionless time unit. Although the errors at large times were extremely small, the errors found within the short duration test were more significant.
Experimental and Numerical Study of Nucleate Pool Boiling Heat Transfer and Bubble Dynamics in Saline Solution
Authors: Liu Qi , Wu Yuxin , Zhang Yang , Lyu Junfu
Published: September 2020

A visual pool boiling experimental device based on ITO coating layer heater and high-speed shooting technology was established for studying the bubble behavior and heat transfer characteristics of saline solution, which is of great significance for ensuring heat transfer safety in nuclear power plants, steam injection boilers and seawater desalination. Volume of fluid method was applied to simulate numerically the liquid–vapor phase change by adding source terms in the continuity equation and energy equation. The predictions of the model are quantitatively verified against the experimental data. It can be found based on the experimental data that the pool boiling heat transfer coefficient is enhanced as the salt concentration increases. Visualization studies and numerical data have shown that the presence and precipitation of salt leads to a decrease in the detachment diameter and growth time of the bubble and an increase in the frequency of detachment, thereby increasing the pool boiling heat transfer coefficient.
An Experimental Study on Flow Boiling Heat Transfer Outside Horizontal Enhanced Tubes
Authors: Ma Liangxiang , Zhang Jianghui , Ma Xiang , Gu Zongbao , He Yan , Kukulka David J. , Li Wei
Published: September 2020

A flow boiling heat transfer experimental investigation on the shell-side of a smooth tube and two enhanced tubes (C-EHT, P-EHT) was performed using R410A as working fluid. The outer surface of the C-EHT tube is covered with special fins having a salient height, and the inner surface has a thread structure with the same distribution density. The outer surface of the P-EHT tube has lots of tiny pits formed by high-strength sandblasting and smooth inner surface. The inlet and outlet vapor quality is 0.2 and 0.8 at a saturation temperature of 279K. The flow boiling experimental results show that the evaporation heat transfer coefficient of C-EHT tube is the largest among the tested tubes. However, for the P-EHT tube, its heat transfer coefficient is lower than that of smooth tube. C-EHT tube with special fins has higher heat transfer area, which can also intensify the interfacial turbulence with increasing fins. The reason why the flow boiling heat transfer coefficient of the P-EHT tube is lower than that of the smooth tube is that the diameter of the pit on P-EHT tube is too small to form the nucleation cites, which results in bubble retention under the condition of low mass flux and deteriorates the flow boiling heat transfer performance.
Micro-Computed Tomography Pore-Scale Study on Natural Convection in a Cubic Cavity Filled With Complex Porous Medium
Authors: Wang Xu , Li Peng , Xu Anyi , Liu Zhenyu
Published: September 2020

A pore-scale numerical simulation was carried out in this study to predict the natural convection in a cubic cavity filled with reconstructed porous medium using lattice Boltzmann Method (LBM). The computational porous domain was established with the micro-computed tomography technique. The natural convection phenomena were predicted with the pore-scale simulation for different thermal boundary conditions and fluid thermal properties. The results show that the natural convection in the present porous domain is more obvious as the side wall is heated compared to that as the bottom wall is heated. The existence of porous structure suppresses the natural convection in the cubic cavity. As Rayleigh number increases, the natural convection in the porous domain is enhanced accordingly. The heat flux distribution on the porous structure surface varies intensively due to the complex flow characteristic in the small pore spaces. The numerical approach presented in this study is to provide a promising solution that can simulate pore-scale natural convection in porous medium and can be further extended for the development of field-scale model for transport processes in porous medium.
Thermally Developing Laminar Liquid Flow and Heat Transfer in Microtubes at Slip Regime
Authors: Gong Wenchi , Shen Jun , Dai Wei
Published: September 2020

Heat transfer enhancement is usually accompanied by an increase in pressure drop. With the implementation of the various drag reduction methods, the researches and applications of DR methods in heat transfer enhancement have attracted more and more attention. The research on drag reduction by introducing superhydrophobic surface shows that the slip regime plays an important role in drag reduction. This study numerically investigated thermally developing laminar liquid flow and heat transfer in microtubes at slip regime, with a hydraulic diameter of 200 μm, a constant heat flux of 105 W/m2, a Re of 100 and a slip length ls ranging from 2 μm to 20 μm. The dimensionless thermal entrance length increases with the increased slip length. The results show that microtube with slip boundary has the larger local Nusselt number and a longer thermal entrance length compared with available experimental data of non-slip boundary. Local and average Nusselt numbers are obtained, and start high and rapidly decrease with the increased dimensionless axial distance. Meanwhile, Nusselt number increases with the increased slip length. The correlations of the dimensionless thermal entrance length and local Nusselt number have mean absolute relative deviation of no more than 0.12% and 1.53% respectively, which can be used to optimize microchannel heat sinks.
Transient Performance of Fixed-Bed Regenerators for Energy Recovery in Building Applications
Authors: Ramin Hadi , Krishnan Easwaran N. , Annadurai Gurubalan , Simonson Carey J.
Published: September 2020

A small-scale test facility is developed to determine the sensible effectiveness of a Fixed-Bed Regenerator (FBR) and the results are used to validate a numerical model. The numerical and experimental results for quasi-steady-state conditions are in a good agreement within the experimental uncertainty bounds. At quasi-steady-state condition, the outlet temperature of FBR varies with time but cyclically repeats itself; this is an important difference between FBR (regenerator) and recuperator heat exchangers. The outlet temperature of recuperator heat exchangers reaches a constant value during the steady-state operation. The quasi-steady-state temperature profile is used to determine the sensible effectiveness of FBRs.

However, FBRs undergo several cycles to reach the quasi-steady-state condition. The prediction of the duration of the transient duration of FBR is important for performance testing that could save money and time. CSA (Canadian Standards Association) recommends operating FBR for at least one hour to achieve a quasi-steady-state condition. This paper addresses the heat transfer behavior of FBRs during their transient operation. The initial transient cycles depend on the cycle period of FBR, air flow rate and the thermal condition of the exchanger at the beginning of the test. The small-scale FBR test facility is used to study the transient behavior of FBRs and this is the main focus of this paper.

The temperature profile during the transient condition of FBR is obtained and the results are compared with the numerical model. The effects of the mass flow rate of air and the cycle duration on the transient period of FBR are studied. The results show that FBR reaches a quasi-steady state operation in less than 30 minutes. The results will be useful for understanding the time required for performance testing, which will reduce the cost and time of each test.
Furnace Design for Improved Exhaust Gas Circulation and Heat Transfer Efficiency
Authors: Brimmo Ayoola T. , Ali Mohamed I. Hassan
Published: September 2020

In the aluminum production industry, metal furnaces are operated by diffusion flame over the metal surface to maintain the aluminum metal at the set point temperature for alloying and casting. Heat is transferred from the flame and its exhaust gases to the metal surface via radiation and convection. The exhaust gases leaves through the furnace’s chimney carrying a significant amount of waste heat to the atmosphere. Furnace efficiency could be improved by enhancing the heat transfer inside the furnace. In this study, a validated full-scale 3-D CFD model of a natural gas fired aluminum furnace is developed to investigate the effect of flue gas ventilation configurations and burner operating conditions on the heat transfer inside the furnace. Onsite measurements are carried out for the fuel and airflow rates as well as flue gas temperature. Four flue ventilation configurations are considered with eight furnace’s operation modes. The flue-gas’s waste-heat varies from 49–58%, with the highest value occurring at the high-fire operating mode. This indicates a significant room for improvement in the furnace performance. Results suggest that a symmetrical positioning of the exhaust duct favors effective exhaust gas circulation within the furnace and hence, increases hot-gases’ heat-transfer effectiveness inside the furnace. These results provide some guidelines for optimal aluminum reverberatory furnace designs and operation.
On Classification and Quantification of Sensory Parameters in Judging Mirror Surface: Appearance of a Turned Aluminum Alloy Surface
Authors: Ihara Motohiro , Yamaji Iwao , Matsubara Atsushi
Published: September 2020

Machined surfaces are judged to determine machining conditions. Quantitative parameters like surface roughness and sensory parameters, such as glossiness, cloudiness, sense of discomfort and so on, of the tester, are used as the criteria. Sensory parameters can be dominant especially in judging mirror surfaces with low surface roughness. Such parameters and their representations, however, depend on each tester’s experience. Consequently, we cannot quantitatively evaluate mirror surfaces considering human sensory parameters. In this research, we aim to classify and quantify sensory parameters, and evaluate mirror surfaces quantitatively. In this report, We analyzed the appearance of the turned surface of an aluminum alloy (A2017) under different cutting conditions, focusing on ‘glossy’ and ‘cloudy’ surfaces. Two testers visually inspected the surfaces. The surface shape was measured with a surface roughness measuring device. Additionally, images of the surfaces were obtained with two different illumination configurations. Consequently, it was expected that fine irregularities on the surface influenced the surface appearance and images. Furthermore, the distribution of the light reflection coefficient was calculated from the measured shape data, based on the Beckmann’s theory on the scattering of electromagnetic waves. Consequently, the sensory evaluation, the surface images and the calculation of the light reflection coefficient provided the same trends and conclusions.
Behavior Modeling for Product Design Support Focusing on Topological Information of Components
Authors: Hatano Itsuki , Wakamatsu Hidefumi , Morinaga Eiji
Published: September 2020

In recent years, with globalization in industry, there is a concern about increase of defects caused by using products in unexpected ways. To solve this problem, a method to predict such defects in a product in advance in the design stage has been proposed, in which behavior of a product and physical phenomena caused by a way of usage are represented by Petri net. However, in order to achieve a more accurate prediction, it is necessary to consider topological information about components of a product. In this research, we aim to represent topological information about elements of an electric circuit, and to make it possible to detect failures in cooperation with the method of the previous research. By modeling each element of an electrical circuit by Petri net and connecting them each other, it is possible to build a model that represents topological information about the circuit, and it can be checked whether there is a closed circuit and which element the current flows through. In addition, by reflecting the information about the circuit to the conventional model, more accurate failure detection can be performed. The fundamental effectiveness of the method was shown by case studies using an example circuit.
Application of MOSA Algorithm in Gleeble Testing Model Updating
Authors: Xu Dong , Zhou Kai , Tang J.
Published: September 2020

This research concerns the parametric identification of Johnson-Cook constitutive model which is frequently used to describe the mechanical behavior of metal material at high temperature. An improved multi-objective simulated annealing (MOSA) algorithm is introduced to update Johnson-Cook model based on Gleeble testing data for Steel T24. Our case study produces Pareto solutions ranked by the error corresponding to each parameter to be optimized. This algorithm improves the previous methods and yields a more suitable solution corresponding to the actual situation.
Changes in noise levels in the city of Madrid during COVID-19 lockdown in 2020
Authors: Asensio César , Pavón Ignacio , de Arcas Guillermo
Published: September 2020

The lockdown that Madrid has suffered during the months of March to June 2020 to try to control and minimize the spread of COVID-19 has significantly altered the acoustic environment of the city. The absence of vehicles and people on the streets has led to a noise reduction captured by the monitoring network of the City of Madrid. In this article, an analysis has been carried out to describe the reduction in noise pollution that has occurred and to analyze the changes in the temporal patterns of noise, which are strongly correlated with the adaptation of the population's activity and behavior to the new circumstances. The reduction in the sound level ranged from 4 to 6 dBA for the indicators Ld, Le, and Ln, and this is connected to a significant variation in the daily time patterns, especially during weekends, when the activity started earlier in the morning and lasted longer at midday, decreasing significantly in the afternoon.
Test–Retest Reliability of activPAL in Measuring Sedentary Behavior and Physical Activity in People With Type 2 Diabetes
Authors: Alothman Shaima , Hoover Jeffrey C. , Alshehri Mohammed M. , Alenazi Aqeel M. , Wick Jo , LeMaster Joseph , Rucker Jason , Kluding Patricia M.
Published: September 2020

Background: To investigate how changes in sedentary behavior relate to health outcomes, it is important to establish the test–retest reliability of activity monitors in measuring habitual sedentary behavior in people with type 2 diabetes (T2D) as a prerequisite for interpreting this information. Thus, the authors’ objective was to examine the test–retest reliability of a common activity monitor (activPAL™) in measuring sedentary behavior and physical activity in people with T2D. Methods: Sedentary-time, standing-time, stepping-time, step-count, and sit-to-stand transitions were obtained from two 7-day assessment periods separated by at least 1 week. Test–retest reliability was determined with the intraclass correlation coefficient (ICC) to compare sedentary and activity measures between the 2 time points. Results: A total of 30 participants with self-reported T2D completed the study (age 65 [6] y, 63% women, body mass index 33.3 [5] kg/m2). High test–retest reliability was found for sedentary-time (ICC = .79; 95% confidence interval [CI], .61–.89) and standing-time (ICC = .74; 95% CI, .53–.87). Very high test–retest reliability was found for stepping-time (ICC = .90; 95% CI, .81–.95), step-count (ICC = .91; 95% CI, .83–.96), and sit-to-stand transitions (ICC = .90; 95% CI, .79–.95). Conclusion: The activPAL™ device showed high to very high test–retest reliability in measuring all tested activity categories in people with T2D.
In Vitro
Study To Evaluate the Bioactivity of Freezing a Heparin-Based Dalbavancin Lock Solution
Authors: Rubia Marta , Cordero Andrea , Pérez-Granda María Jesús , Cercenado Emilia , Pascual Cristina , Muñoz Patricia , Guembe María
Published: September 2020

The use of dalbavancin as a catheter lock solution must be addressed in depth before implementation in clinical practice. We assessed whether a heparin-based dalbavancin lock solution could be frozen in single-dose vials for 6 months without affecting its bioactivity against biofilms of methicillin-resistant
Staphylococcus aureus
(MRSA) and methicillin-resistant
Staphylococcus epidermidis
(MRSE). Over 6 months, we tested the bioactivity of a frozen solution of dalbavancin (≈1 mg/ml) plus heparin (60 IU) in terms of CFU counts and metabolic activity against biofilms of
Staphylococcus aureus
ATCC 43300 (MRSA) and
Staphylococcus epidermidis
ATCC 35984 (MRSE).
Possible Involvement of a Tetrathionate Reductase Homolog in Dissimilatory Arsenate Reduction by
Anaeromyxobacter
sp. Strain PSR-1
Authors: Muramatsu Fumika , Tonomura Mimori , Yamada Mikina , Kasahara Yasuhiro , Yamamura Shigeki , Iino Takao , Amachi Seigo
Published: September 2020

Dissimilatory As(V)-reducing prokaryotes play significant roles in arsenic release and contamination in groundwater and threaten the health of people worldwide. Generally, such prokaryotes reduce As(V) by means of a respiratory As(V) reductase designated Arr. However, some dissimilatory As(V)-reducing prokaryotes such as
Anaeromyxobacter
sp. strain PSR-1 lack genes encoding Arr, suggesting the involvement of other protein in As(V) reduction. In this study, using multiple proteomic and transcriptional analyses, it was found that the dissimilatory As(V) reductase of strain PSR-1 was a protein closely related to the tetrathionate reductase catalytic subunit (TtrA). Tetrathionate reductase is known to play a role in anaerobic respiration of
Salmonella
on tetrathionate, but strain PSR-1 showed neither growth on tetrathionate nor significant tetrathionate reductase enzyme activity. These results suggest the possibility that TtrA homologs encoded in a wide variety of archaeal and bacterial genomes might function as dissimilatory As(V) reductases.