bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of a hybrid double stator bearingless switched reluctance motor
Authors: Sun Yukun , Yang Fan , Yuan Ye , Yu Fengyuan , Xiang Qianwen , Zhu Zhiying
Published: October 2018

A hybrid double stator bearingless switched reluctance motor with advantages of high suspension output, small loss and weak coupling is presented. This motor can realise electric/power generation and radial two‐degree‐of‐freedom suspension. The biased magnetic field for producing radial force is provided by a permanent magnet, which reduces system power consumption. Self‐decoupling is realised between a torque system and suspension system according to the mechanical structure design. Furthermore, the radial force is approximately constant when the suspension current is constant, thereby improving the controllability of the system. The operation principle is introduced and the electromagnetic characteristics are analysed through the time‐stepping finite element method. This analysis verifies the effectiveness of the theoretical analysis.
Agent‐based ARP cache poisoning detection in switched LAN environments
Authors: Sakhawat Daniyal , Khan Abdul Nasir , Aslam Mudassar , Chronopoulos Anthony T.
Published: October 2018

Address resolution protocol (ARP) cache poisoning is mostly used to perform man‐in‐the‐middle (MITM) and denial of service (DoS) attacks for sniffing and network services disruption, respectively, in switch LAN networks. The former attack affects the privacy of a network user, whereas the latter attack causes huge damage to networks in terms of unavailability of services. There are many security solutions that provide protection against such type of attacks at firewall level with the assumption that an insider attack does not exist. However, the most damaging and severe attacks on universities database servers to well‐known banking system have been caused by insider malicious users. In this study, the authors propose an agent‐based ARP cache poisoning detection (AACPD) scheme that detects the MITM and DoS attacks in a switch LAN environment. The objective of this scheme is to provide protection from insider malicious users. The proposed AACPD is compared with similar existing schemes in a real‐time environment. The experimental results show that AACPD efficiently and accurately detects attackers with minimum effect on network performance as compared to similar existing schemes.
The overhead transmission line protection scheme for the voltage‐source converter‐based HVDC grids
Authors: Wang Yanting , Zhang Baohui , Fan Xinkai
Published: October 2018

The fast DC line protection technology is one of the main challenges to high‐voltage direct current (HVDC) grids. Based on the Zhangbei HVDC grid project, this paper proposes a non‐unit overhead transmission line protection scheme for bipolar voltage‐source converter‐based HVDC grids equipped with DC circuit breakers. The voltage gradient is used to detect faults rapidly and start the protection algorithm, and the voltage derivative criterion is adopted to discriminate the internal faults from the external ones. Two kinds of faulty pole identification methods are proposed based on the propagation characteristics between the line‐ and zero‐mode voltages, ensuring the selectivity of the protection. The Zhangbei HVDC grid model is built in power systems computer‐aided design/electromagnetic transients including DC and the performance of the proposed protection scheme is verified by simulation results of various fault conditions.
Shockwave phenomena in an inhibited gas‐to‐liquid hydrocarbon transformer oil under lightning impulse voltages
Authors: Lu Wu , Li Feng , Gao Yuan , Zhao Wenbin
Published: October 2018

Gas‐to‐liquid (GTL) transformer oil is increasingly considered as an alternative to conventional mineral oils, due to its consistent performance, high purity and essentially free of sulphur. This high interest has led to growing research attention on streamer and breakdown performance of GTL oil. A large effort has been made to characterise the streamer phenomena of GTL oil. However, the secondary effect of shockwaves, which are produced synchronously with the propagation of streamers, is not well studied. Shockwave phenomena in a GTL oil under standard lightning impulse voltages were studied using a 10 mm point‐plane gap and the Schlieren photograph technology. Shockwave propagation velocity and shape were measured in order to quantitatively describe the pressure profiles inside the streamer channels.
Pumped energy storage system technology and its AC–DC interface topology, modelling and control analysis: a review
Authors: Bitew Girmaw Teshager , Han Minxiao , Mekonnen Sifrash A. , Patrobers Simiyu , Khan Zmarrak W. , Tuan Luu K.
Published: October 2018

Pumped‐storage hydropower plants can contribute to a better integration of intermittent renewable energy and to balance generation and demand in real time by providing rapid response generation. The utilisation of variable‐speed pump‐turbine units with a doubly fed induction machine is being progressively applied due to its overall efficiency and high level of operating flexibility. This study presents state‐of‐the‐art pumped energy storage system technology and its AC–DC interface topology, modelling, simulation and control analysis. It also provides information on the existing global capacities, technological development, topologies and control strategies of the pumped‐storage system. This report also outlines the analysis of dynamic performances of the system. It also attempts to recommend the future works in this area. This study concludes that pumped storage is the most suitable technology for small autonomous island grids and massive energy storage, where the energy efficiency of pumped storage varies in practice. Around the world, the size of the pumped‐storage plant mostly lies in the range of a small size to 3060 MW. The back‐to‐back voltage source converter topology is mostly conducted due to its significant features. Due to its imperative features, the vector control strategy is widely used. The pumped‐storage plant is dedicated to power management and stability regulation of grid and isolated power systems.
Power conditioning system control strategy for cascaded H‐bridge converter battery energy storage system
Authors: Hasabelrasul Hashim , Yan Xiangwu , Gadalla Abuzaid Saeed
Published: October 2018

Large capability for a cascaded H‐bridge converter battery energy storage system is one of the effective tools to solve the grid‐connection problem of renewable energy resource such as large‐scale wind farm. The power conditioning system (PCS) control strategy is used proportional‐resonant regulator to implement the control with decoupled current control for instantaneous power. The balancing control of the state of charge (SOC) is divided into individual balancing control between bridges is implemented by means of the proportional controller and cluster control between three phases is based on the zero‐sequence‐voltage injection. The system designed in high‐power medium voltage 6.6 kV combining 30 LiFePO4 (lithium iron phosphate) battery units with cascaded H‐bridge multilevel inverter. The simulation results of SOC balancing control was carried out. As a result, a steady‐state error of PCS can be smaller and three‐phase output power balancing has been achieved, thus, a system simulation model has verified the effectiveness of control strategy. The waveforms of PCS in quadrant operation show voltage and current at active power 1 MW.
Probabilistic analysis of payback period for AC–DC transmission and distribution asset expansion projects
Authors: Bin Li , Shahzad Muhammad , Bing Qi , Shoukat Muhammad U. , Fahal Nabeel A.M. , Simiyu Patrobers , Islam Rabiul
Published: October 2018

In this study, a new concept of statistical distribution of payback period is calculated for AC–DC transmission and distribution asset expansion projects. For calculation of the payback period, uncertainty is considered with cost and benefit. The Gaussian distribution is considered for correlated input cost and benefit variates. For more examination point of view, the distribution of the payback period is calculated with different correlation coefficients between cost and benefit. The main advantage of this study is to draw the probability distribution function of the payback period in terms of cost and benefit because most of the industrialist are often interested in cost and benefit analysis of AC–DC transmission and distribution asset expansion projects. An example is considered for evaluation of the proposed model.
The responses of the earth’s magnetopause and bow shock to the IMF Bz and the solar wind dynamic pressure: a parametric study using the AMR-CESE-MHD model
Authors: Wang Juan , Guo Zhifang , Ge Yasong S. , Du Aimin , Huang Can , Qin Pengfei
Published: October 2018

We have used the AMR-CESE-MHD model to investigate the influences of the IMF Bz and the upstream solar wind dynamic pressure (Dp) on Earth’s magnetopause and bow shock. Our results present that the earthward displacement of the magnetopause increases with the intensity of the IMF Bz. The increase of the northward IMF Bz also brings the magnetopause closer to the Earth even though with a small distance. Our simulation results show that the subsolar bow shock during the southward IMF is much closer to the Earth than during the northward IMF. As the intensity of IMF Bz increases (also the total field strength), the subsolar bow shock moves sunward as the solar wind magnetosonic Mach number decreases. The sunward movement of the subsolar bow shock during southward IMF are much smaller than that during northward IMF, which indicates that the decrease of solar wind magnetosonic Mach number hardly changes the subsolar bow shock location during southward IMF. Our simulations also show that the effects of upstream solar wind dynamic pressure (Dp) changes on both the subsolar magnetopause and bow shock locations are much more significant than those due to the IMF changes, which is consistent with previous studies. However, in our simulations the earthward displacement of the subsolar magnetopause during high solar wind Dp is greater than that predicted by the empirical models.
Mucopolysaccharidosis and Adulthood: Genetics, Inheritance, and Reproductive Options
Authors: Wilson Alison , Lavery Christine , Stewart Fiona , Thomas Sophie , Cavell Deborah , Brandon Rebecca , Murphy Elaine , Wilcox Gisella , Talaulikar Vikram
Published: October 2018

The mucopolysaccharide diseases are a group of heterogeneous, inherited conditions that are characterized by the deficiency of specific lysosomal enzymes. These lysosomal enzymes are responsible for the breakdown of glycosaminoglycans (GAGs), which are a key component of connective tissue. When lysosomal enzymes are deficient, the resultant build-up of GAGs impacts on cellular functioning. The resultant clinical manifestations are multisystemic, progressive, and life-limiting. Although each condition is characterized by its own constellation of symptoms; there is a great deal of heterogeneity and overlap in the clinical manifestations (both within and between mucopolysaccharidosis [MPS] subtypes). Increasing understanding of the genetic and biochemical basis of the MPS diseases has paved the way for a wave of exciting developments in their treatment and management. New treatments have changed the face of many of the MPS diseases; and as a result, management has moved beyond the pediatric clinic into the adult clinic. For the first time, individuals with MPS are living into adulthood with fewer limitations than the natural course of their disease would predict. It is essential that in this new age of MPS disease management, early diagnosis achieved and those at risk of having a child affected by one of these conditions are appropriately counseled in relation to their reproductive options. It is also important that individuals with MPS are counseled independently, at an appropriate age (or when they have capacity) about the basis of their disease and what this means for them. Here we discuss the diagnosis and inheritance of the MPS conditions; specifically focusing on genetic counseling requirements. We also discuss the outcomes of a research study, undertaken by the UK Mucopolysaccharide Disease Society, into the experiences of women with MPS who have had successful pregnancies.
Daily Life Coping with Mucopolysaccharidoses: A Few Devices Showing the Possibilities of Helping Morquio Patients
Authors: Wiesbauer Widmer Christine , Wiesbauer Alfred , Wiesbauer Sophie
Published: October 2018

Mucopolysaccharidoses (MPS) show a strong involvement of the skeleton and the joints and partly a significant reduction in growth. Nevertheless, adult patients are particularly interested in being recognized as integrated members of society, and having families and professions. Because of their physical limitations, they always reach their limits. In recent years, numerous devices have come on the market and/or have been improved, which can make everyday life easier. Various improvements are due to new materials such as carbon or silicon and due to electronics/robotics. Amenities such as automated doors, motion detectors, lifts, smartphones with integrated remote control, among others, originally invented for normal consumers prove to be a great help for handicapped persons. What was meant for the masses proves to be extremely useful for patients with MPS.
Lysosomes and Their Role in Mucopolysaccharide Disorders: New Insights
Authors: Kircher Susanne , Taylor Thomas
Published: October 2018

Mucopolysaccharidoses (MPS) belong to the group of lysosomal storage diseases and are characterized by the deficiency of lysosomal enzymes involved in the degradation of glycosaminoglycans (GAGs). They are caused by inherited enzyme deficiencies that result from mutated genes producing defective enzymes. In MPS, the step-wise degradation process of GAG chains is impaired, and thus pieces of undegraded chains remain in the lysosomes impeding other processes in these cell organelles. Several enzymes—currently 12 are known—are necessary to degrade GAGs to sugars and small chemical substances, such as sulfate- or amino groups, to prepare them for excretion via exocytosis or to reintegrate them into new molecules by recycling. GAGs are major components of the connective tissue but play a role in shaping the vicinity of each cell surface as well; hence, any disturbance in their metabolism causes problems not limited to connective tissue but other tissues and organs. Therefore, MPS are multisystemic diseases involving many organs and restrict a wide range of organ functions. Organomegaly, typical skeletal changes known as “dysostosis multiplex,” excessive storage in the nervous system with neurologic symptoms and impaired cognitive function have been known as the typical symptoms of the first classical MPS types for some time now. Because of new therapies and improved care, the life expectancy of MPS patients has increased significantly. Results of investigations that have only become available recently and new methods allowing for fine-meshed observation have revealed unexpected findings. These outcomes are not limited to excessive storage: patients show unpredictable reactions of the immune system, chronic inflammation, changes in metabolic pathways not directly related to the connective tissue, such as chronic arthritis, osteopenia, Parkinson-like symptoms, signs of dementia, and many more, which suggest that lysosomes have many more roles than just degradation of no longer needed macromolecules.
Albumin, Prealbumin, and Transferrin May Be Predictive of Wound Complications following Total Knee Arthroplasty
Authors: Roche Martin , Law Tsun , Sodhi Nipun , Rosas Samuel , Elson Leah , Summers Spencer , Sabeh Karim , Mont Michael , Kurowicki Jennifer
Published: October 2018

Nutritional status has become increasingly important in optimizing surgical outcomes and preventing postoperative infection and wound complications. However, currently, there is a paucity in the orthopaedics literature investigating the relationship between nutritional status and wound complications following total knee arthroplasty (TKA). Therefore, the purpose of this study was to determine the prevalence of (1) postoperative infections, (2) wound complications, (3) concomitant infection with wound (CoIW) complication, and (4) infection followed by wound complication by using (1) albumin, (2) prealbumin, and (3) transferrin levels as indicators of nutritional status. These four different outcome measures were chosen as they are encountered commonly in daily clinical practice. A retrospective review of a national private payer database for patients who underwent TKA with postoperative infections and wound complications stratified by preoperative serum albumin (normal: 3.5–5 g/dL), prealbumin (normal: 16–35 mg/dL), and transferrin levels (normal: 200–360 mg/dL) between 2007 and 2015 was conducted. Patients were identified by Current Procedural Terminology (CPT), International Classification of Disease, ninth revision (ICD-9) codes, and Logical Observation Identifiers Names and Codes (LOINC). Linear regression was performed to evaluate changes over times. Yearly rates of infection, as well as a correlation and odds ratio analysis of nutritional laboratory values to postoperative complications, were also performed. Our query returned a total of 161,625 TKAs, of which 11,047 (7%) had postoperative wound complications, 18,403 (11%) had infections, 6,296 (34%) had CoIW, and 4,877 (4%) patients with infection developed wound complications. Albumin was the most commonly ordered laboratory test when assessing complications (96%). Wound complications, infections, CoIW, and infection with wound complications after were higher in those below the normal range: albumin <3.5 g/dL (9, 14, 6, and 5%), prealbumin <15 mg/dL (20, 23, 13, and 12%), and transferrin <200 mg/dL (12, 17, 6, and 6%). Preoperative albumin, prealbumin, and transferrin values falling below the normal range represented an increased risk for postoperative complications. Those patients who were in the normal range, however, did not have an increased risk. Therefore, our results suggest that preoperative nutritional optimization can play an important role in reducing the risk for postoperative complications.
The Role of Umbilical Cord Blood Concentration of IGF-I, IGF-II, Leptin, Adiponectin, Ghrelin, Resistin, and Visfatin in Fetal Growth
Authors: Yalinbas Emine , Binay Cigdem , Simsek Enver , Aksit Mehmet
Published: October 2018

Objective Herein, we measured the concentration of insulinlike growth factor I (IGF-I), IGF-II, leptin, adiponectin, ghrelin, resistin, and visfatin in the umbilical cord blood of newborns categorized as “small for gestational age” (SGA), “appropriate for gestational age” (AGA), and “large for gestational age” (LGA). Our aim was to elucidate the link between the levels of these proteins and fetal growth.

Study Design A total of 96 term infants were included and categorized into three weight categories. Their venous cord blood samples were collected to measure the levels of IGF-I, IGF-II, leptin, adiponectin, ghrelin, resistin, and visfatin.

Results IGF-I, visfatin, and leptin levels showed significant differences among the groups. Pairwise comparisons showed that adiponectin (p = 0.023), resistin (p = 0.025), and ghrelin (p = 0.005) levels were significantly lower in the SGA group than in the LGA group. Correlation analyses showed a strong association of IGF-1, IGF-II, and leptin levels with birth weight (r = 0.644, p < 0.001; r = 0.441, p < 0.001; and r = 0.404, p < 0.001, respectively).

Conclusion SGA newborns showed a significantly higher visfatin concentration and lower ghrelin, leptin, resistin, and adiponectin levels than the AGA and LGA newborns did.
PaO2/FiO2 Ratio as Predictor of Mortality in Neonates with Meconium Aspiration Syndrome
Authors: Narayanan Anand , Batra Prerna , Faridi Mohammed , Harit Deepika
Published: October 2018

Objectives Partial arterial pressure of oxygen/fraction of oxygen in inspired air (PaO2/FiO2) ratio has been used as a predictor of outcome in some neonatal conditions, but has not been used in meconium aspiration syndrome (MAS). This study was conducted with the objective to study if the PaO2/FiO2 ratio of < 200 at 6, 12, and 24 hours of life can predict mortality in neonates with MAS.

Study Design Two hundred neonates with MAS were included in the study. PaO2/FiO2 ratio was calculated at 6, 12, and 24 hours of life. Sensitivity, specificity, predictive values, and likelihood ratio at cut-off < 200 to predict mortality was calculated.

Results PaO2/FiO2 ratio at cut-off of < 200 was found to predict mortality in neonates with MAS with 94.1% sensitivity and 96.6% specificity. It was also able to predict development of severe MAS.

Conclusion PaO2/FiO2 at < 200 can predict all-cause mortality in neonates with MAS. It can be used as vital tool in identifying newborns at high risk, thus helping in focused care.
Effect of Femoral Antetorsion on Tibiofemoral Translation and Rotation in the Anterior Cruciate Ligament Deficient Knee
Authors: Omar Mohamed , Al Saiegh Yousif , Liodakis Emmanouil , Stuebig Timo , Guenther Daniel , Steimer David , Hawi Nael , Krettek Christian , Suero Eduardo M.
Published: October 2018

We aimed to investigate how increased or decreased femoral antetorsion would affect the biomechanics of the knee in an anterior cruciate ligament (ACL)-deficient cadaveric model. We hypothesized that external or internal rotation of the distal femur, achieved through a femoral osteotomy, would affect the magnitude of tibiofemoral translation and rotation. Navigated measurements of tibiofemoral translation and rotation during the anterior drawer, Lachman, and pivot shift tests were performed on six whole-body cadaveric specimens in each of the following four conditions: native, ACL-deficient knee, ACL-deficient knee and 20-degree internal distal femur rotation, and ACL-deficient knee and 20-degree external distal femur rotation. Increased femoral antetorsion significantly reduced anterior tibial translation in the ACL-deficient knee during the anterior drawer, Lachman, and pivot shift tests (p < 0.05). Conversely, decreasing femoral antetorsion resulted in an increase in anterior tibial translation in the anterior drawer (nonsignificant), Lachman (p < 0.05), and pivot shift (p < 0.05) tests. Internally rotating the distal femur significantly reduced the magnitude of tibial rotation during the pivot shift test in the ACL-deficient knee (p < 0.05), whereas external rotation of the distal femur significantly increased tibial rotation (p < 0.05). The magnitude of femoral antetorsion affects tibiofemoral translation in an ACL-deficient cadaveric mode. Internally rotating the distal femur 20 degrees reduced the magnitude of tibial translation and rotation similar to that of the native knee, whereas externally rotating the distal femur aggravated translational and rotational instability.
Effects of an Intervention to Improve Life-Space Mobility and Self-Efficacy in Patients following Total Knee Arthroplasty
Authors: Hiyama Yoshinori , Kamitani Tsukasa , Mori Kazuaki
Published: October 2018

Life-space mobility describes the spatial areas through which an individual moves, and the frequency and need for assistance. Although patients with knee osteoarthritis (OA) have shown restricted life-space mobility, total knee arthroplasty (TKA) does not improve it beyond preoperative levels. Life-space mobility after TKA was influenced by self-efficacy for walking tasks; thus, an intervention to improve self-efficacy for walking tasks may contribute to better life-space mobility. We provided a walking event including several walking tasks as the intervention. We assessed the effect of the walking event on life-space mobility and self-efficacy for walking tasks in patients following TKA. In this nonrandomized controlled trial, patients who underwent primary TKA were recruited. After recruitment, patients who could not participate in the walking event due to scheduling conflicts were included in the control group. The walking event consisted of 3.5 km of walking course and included walking tasks as follows: crossing at the crosswalk, walking up- and downstairs without a railing, walking along dirt roads, and walking up and down a slope. The primary outcome was life-space mobility measured using Life-Space Assessment (LSA) and self-efficacy for walking tasks measured using the modified Gait Efficacy Scale (mGES). We enrolled 104 patients, of whom 36 were assigned to the intervention group and participated in the walking event. Participants in the intervention group had significantly better LSA score (adjusted mean difference between groups: 13.9; 95% confidence interval: 12.4–15.5; p < 0.001) and mGES score (adjusted mean difference between groups: 13.8; 95% confidence interval: 12.4–15.1; p < 0.001) than the control group even after adjusting for age, gender, body mass index, elapsed time from surgery, the severity of knee OA of nonoperated limb, and patient-reported functional outcome. The walking event including various walking tasks improved life-space mobility and self-efficacy in patients following TKA. It is important to design a program that can improve self-efficacy for walking tasks through mastery experiences to improve life-space mobility after TKA.
Periprosthetic Fracture following Partial Knee Arthroplasty
Authors: Brown Nicholas M. , Engh Gerard , Fricka Kevin
Published: October 2018

Partial knee arthroplasty is a procedure with long-term successful outcomes. However, there are several potential complications including retained cement fragments, bearing dislocation, infection, component loosening, medial collateral ligament injury, and overcorrection, leading to progressive arthritis. Periprosthetic fracture is an uncommon complication, with multiple reports showing an incidence of less than 1%. Hence, there are no established algorithms to guide treatment. A consecutive series of 2,464 patients who underwent partial knee arthroplasty between January 2009 and April 2017 was reviewed. We identified 16 patients with early periprosthetic fracture, with an incidence of 0.6%. All of these were tibial fractures, which occurred at a mean of 35 days postoperatively. There were 5 males and 11 females, with an average age of 70 years at the time of surgery. Average follow-up was 62 months. Two patients had contralateral compartment insufficiency fractures that were successfully treated nonoperatively, five patients immediately underwent total knee arthroplasty (TKA), and nine patients underwent open reduction internal fixation (ORIF). Two of these cases had a failed ORIF and required conversion to TKA. Seven patients were successfully treated with a medial buttress plate in compression. Average Knee Society Score at final follow-up was 81, and average flexion was 115 degrees, with no patients having greater than 5-degree flexion contracture. Periprosthetic fracture following partial knee arthroplasty resulted in a high rate of conversion TKA. However, ORIF in select patients resulted in fracture healing and retention of the partial knee replacement. All patients were successfully treated with low complication rates, excellent range of motion, and acceptable knee scores at final follow-up.
Carpal Alignment: A New Method for Assessment
Authors: Selles C. , Ras L. , Walenkamp M. , Maas M. , Goslings J. , Schep N.
Published: October 2018

Background Carpal alignment may be used as a tool to evaluate fracture reduction in patients with distal radius fractures. However, there is little consensus on how to measure and quantify carpal alignment.

Purpose The aim of this study was to compare the inter- and intraobserver variability of a new perpendicular method with the existing method in fractured and unfractured wrists. Additionally, the normal distribution of carpal alignment in unfractured wrists was investigated.

Patients and Methods Carpal alignment was assessed on lateral plain radiographs using two different methods, one described by Ng and McQueen and another newly proposed method, the perpendicular method. Using the perpendicular method, the observer draws one line along the inner rim of the volar cortex of the radius and one perpendicular line to the center of the capitate. The carpus is aligned when the line along the inner rim transects the center of the capitate. Three examiners measured the carpal alignment in 50 patients with nonfractured and 50 patients with fractured distal radius. Intra- and interobserver variability for both methods were determined.

Results The interobserver coefficient for the perpendicular method was 0.98 and that for the Ng method was 0.86. The intraobserver coefficients for three examiners were 0.89, 0.62, and 0.63, respectively, for the Ng method. For the perpendicular method, the intraobserver variability was 0.96, 0.89, and 0.72, respectively. In patients with unfractured wrists, the mean perpendicular to the center of the capitate was 0.25 mm dorsally.

Conclusion The new proposed method is a reproducible method for measuring carpal alignment with a high inter- and intraclass coefficient.

Clinical Relevance This method of measurement allows for a reproducible technique for measuring carpal alignment.
Dorsal Lunate Facet Fracture Reduction Using a Bone Reduction Forceps
Authors: Lans Jonathan , Alvarez Josefina , Kachooei Amir , Ozkan Sezai , Jupiter Jesse
Published: October 2018

Background The dorsal lunate facet fragment represents part of a complex articular injury of the distal radius and is challenging to reduce through a standard volar approach. We propose reduction through a standard volar approach and intraoperative dorsal lunate facet reduction using a bone forceps. To evaluate the postoperative reduction, we used computed tomography (CT) scan.

Methods We retrospectively included 60 patients with a median follow-up of 44 weeks. Fracture reduction was evaluated using pre- and direct postoperative CT scans of the wrist, measuring the articular gap and step of the sigmoid notch. The range of motion was evaluated clinically by the treating physician. Bivariate analysis was performed to compare pre- and postoperative radiographic measurements and to compare wrist range of motion.

Results When comparing the injured with the uninjured wrist, there was a significant difference in flexion, extension, pronation, and supination. In 87% of the patients, there was complete radiographic reduction of the fracture.

Conclusion This study shows that dorsal ulnar lunate facet fracture fragments in distal radius fractures can be reduced through a standard volar approach with the help of an intraoperative bone reduction forceps. Using wrist CT, we showed that 87% of the patients with a dorsal ulnar lunate facet fragment had a postoperative articular step or gap of <1 mm.

Level of Evidence: This is a level IV, therapeutic study.
“Post Traumatic Brain Abscess Mimicking as Pneumatocele”: An Uncommon Presentation
Authors: Varshney Rahul , Bhakal Nitin , Gupta L. , Pandey Sharad , Sharma Rajesh
Published: October 2018

Pneumatocele is a very rare complication that follows head injury. Pneumatocele can result due to a craniodural fistula, formed either after a fracture involving air sinuses, roof of middle ear, or depressed fracture of skull. Gas-containing brain abscess is a life-threatening condition, which requires immediate diagnosis and prompt therapeutic intervention. The predisposing factors include hematogenous spread, contiguous infection, and abnormal fistulous communication due to head injury. This is a rare case in which the patient had a history of head trauma due to road traffic accident with frontal contusion and small pneumocephalus, which was managed conservatively 2 years earlier followed by cerebrospinal fluid (CSF) rhinorrhea after 2 months, which was also managed by nonsurgical management. He presented with intractable seizures and features of raised intracranial pressure (ICP) with imaging suggestive of air-containing cavity in frontal region (pneumatocele). Intraoperatively, there was brain abscess with dural defect for which abscess was excised, and dural repair with exteriorization of frontal sinus was done.
On the Moyal deformation of Kapustin-Witten systems
Authors: Cardona S. A. H. , García-Compeán H. , Martínez-Merino A.
Published: October 2018

Using the Weyl-Wigner-Moyal-Groenewold description, a Moyal-deformation of a Kapustin-Witten (KW) system is obtained in this article. Starting from the known solutions of the original equations, some solutions to these deformed equations are obtained. The analytic properties of such solutions are also studied. Finally we find that in the ℏ → 0 limit, the SU(∞) KW equations are obtained.
Optimizing feedstock mixtures of livestock farming wastes to enhance methane yield in biogas production by co-digestion
Authors: Uranga-Soto Manuel Alejandro , Valdez-Torres José Benigno , Báez-Sañudo Manuel Alonzo , Heredia José Basilio , Siller-Cepeda Jorge Humberto , Muy-Rangel María Dolores
Published: October 2018

Different mixtures of feedlot manure, rumen content, and corn stover were used to produce biogas with a large percentage of methane by co-digestion. Biogas components from each mixture were identified and quantified using gas chromatography. Cumulative biogas and methane production was measured for 10 mixtures over the course of 15 days. Response surface methodology was implemented to find the optimum mixture. The largest biogas and methane yields occurred in a mixture composed of 75% feedlot manure, 12.5% ruminal content, and 12.5% corn stover, corresponding to a methane yield of 126 ml CH4·g−1 VS with a 7.5% VS content. These findings show that co-digestion of livestock farming wastes is a promising alternative for the production of renewable energy.
A maximum entropy method for solving the boundary value problem of second order ordinary differential equations
Authors: Jin Congming , Ding Jiu
Published: October 2018

We propose a new method to solve the boundary value problem for a class of second order linear ordinary differential equations, which has a non-negative solution. The method applies the maximum entropy principle to approximating the solution numerically. The theoretical analysis and numerical examples show that our method is convergent.
The dissection of atomic clusters with local structure in Ga-Sn alloy melts
Authors: Zhao Xiaolin , Bai Yanwen , Li XinXin , Wang Changchun , Li Yunfang , Bian Xiufang
Published: October 2018

The statistic short-range order (SRO) structure parameters of the Ga-Sn alloy melt are obtained with the X-ray diffractometer. The local atomic and electronic structures around the absorption atoms of Ga and Sn elements are detected by X-ray absorption fine structure spectrum. Centered on the absorption atom, the atom cluster structure was dissected and the atom cluster model was established. Unlike the ordinary liquid metal structure, the local atomic structure demonstrates that the liquid Ga-Sn alloy is not characterized by a dominant icosahedral short-range order. Specially, Sn atoms aggregate in Ga91.6Sn8.4 alloy, giving rise to a phase separation that exhibits compositional disorder.
Homogenous solidification of undercooled Cu-37.4 wt%Pb monotectic melt
Authors: Sun Xiaosi , Hao Weixin , Ma Teng , Geng Guihong
Published: October 2018

The solidification behavior and solidification structure evolution of Cu-37.4wt%Pb undercooled melt under different undercoolings were studied by the combination of molten glass purification and cyclic superheating. With the increase in the undercooling, the solidification microstructure undergoes the coarse-fine-coarse-layered transition process and the distribution of Pb particles in the solidified structure is changed accordingly. With the distribution function of the second phase droplet under the combined action of nucleation, growth and deposition, the range for the critical undercooling of undercooled melt required for realizing the homogeneous solidification is obtained by solving and simplifying the function and then experimentally verified.
The effect of the length to diameter ratio on capillary discharge plasmas
Authors: Zhang Jiangbo , Li Xingwen , Yang Weihong , Yan Wenrong , Wei Ding , Liu Yi , Yan Guanghu
Published: October 2018

The capillary geometry of discharge plasma sources determines the performance of capillary plasma generators. In this research, 16 types of generators with different geometric sizes and aspect ratios (the length divided by the diameter of the capillary, ranging from 0.67 to 22) were designed. Plasma parameters, including the temperature, static pressure, and velocity, were calculated and analyzed. The results show that the maximum temperature of the plasma decreased with increasing capillary aspect ratios. However, there was a difference between the temperature distributions above and below an aspect ratio threshold of 8.67. The simulations suggest that the aspect ratio threshold of the static pressure for generating shock waves is 15.33. For aspect ratios lower than this value, the maximum static pressure increased with increases in the aspect ratio. Otherwise, a shock wave would be generated, and the distribution of the static pressure would be consistent with distribution 2 (with a shock wave near the nozzle). The maximum velocity decreased as the capillary aspect ratios increased, with a threshold of 8.67. Since the plasma parameters were exponential functions of the aspect ratios, distribution and variation trends of the plasma parameters for different aspect ratios are proposed. These can be used to adjust the electrothermal plasma parameters and to design plasma generators.
Chain of magnetic tunnel junctions as a spintronic memristor
Authors: Raymenants Eline , Vaysset Adrien , Wan Danny , Manfrini Mauricio , Zografos Odysseas , Bultynck Olivier , Doevenspeck Jonas , Heyns Marc , Radu Iuliana P. , Devolder Thibaut
Published: October 2018

In the context of neuromorphic computation, spintronic memristors are investigated for their use as synaptic weights. In this paper, we propose and experimentally demonstrate a resistive synaptic device based on ten magnetic tunnel junctions (MTJs) connected in a serial configuration. Our device exhibits multiple resistance levels that support its use as a synaptic element. It allows for two operating knobs: external magnetic field and voltage pulses (Spin-Transfer Torque). Moreover, it can be operated in different ways. When varying continuously the amplitude of the voltage pulse and/or the magnetic field, eleven resistance states can be reached. In contrast, if the initial state of the chain is reset between every step, a very large number of levels are reached. Ideally, a total of 2N resistance levels could be accessible. This coincides well with the desired analog-like behavior in ideal memristors. Since this device consists of a scalable number of N MTJs, and MTJ technology is continuously optimized and improved, the proposed memristor shows promise as a scalable synapse solution for neuromorphic hardware implementations.
Particle trajectories and mass transport under mechanically generated nonlinear water waves
Authors: Paprota Maciej , Sulisz Wojciech
Published: October 2018

A theoretical model is developed to study the kinematics of water particles and mass transport of wave-induced flow generated in a closed flume. A semi-analytical pseudo-spectral solution to the problem of mechanically generated nonlinear water waves propagating at a constant depth is derived under the potential flow assumptions. Velocity potential and free-surface displacement functions are represented in a form based on Fourier series. The eigenfunction expansions are resolved by means of a Fast Fourier Transform technique and a higher order time-stepping procedure. The derived nonlinear solution of the wavemaker problem is based on Taylor series representation of the free-surface and wavemaker boundary conditions expanded up to an arbitrary truncation order. This technique is employed to study the evolution of a velocity field and particle trajectories under regular gravity waves generated in a wave flume. The instantaneous velocity fields are integrated in time to calculate the particle trajectories and time-averaged spatial distribution of Lagrangian and Eulerian mean velocities. The theoretical results are compared with the available experimental data. A good agreement is observed, which confirms the applicability of the presented theory to the problems of transport processes associated with the propagation of water waves and their generation in the flume.
Contributions of leading and tailing pulse edges to filamentation and supercontinuum generation of femtosecond pulses in air
Authors: Zhan Lindi , Xu Mengning , Xi Tingting , Hao Zuoqiang
Published: October 2018

By simulating the filamentation of femtosecond laser pulses with flat top and different steep leading and tailing edges in air, the influence of pulse edges on the filamentation dynamics and supercontinuum (SC) generation is analyzed. It is found that the filamentation length is determined by the leading edge. The different roles of the pulse edges in the SC generation are further revealed. Under a relative lower laser power, the spectral broadening of the laser pulse originates mainly from the self-phase modulation of both pulse edges induced by the Kerr effect, while under a relative higher power condition, the leading edge plays a dominant role in the blue-side extension of the SC due to electron generation.
Property-structure relationship in lead-free relaxors Ba5RSn3Nb7O30 with tungsten bronze structure
Authors: Yang Zi Jin , Zhu Xiao Li , Liu Xiao Qiang , Chen Xiang Ming
Published: October 2018

Lead-free relaxors Ba5RSn3Nb7O30 (R = La, Nd, Sm) with a tetragonal tungsten bronze structure were prepared by a standard solid-state reaction process, and the dielectric and ferroelectric properties were systematically determined together with the structures and microstructures. Rietveld refinement results suggested that a single-phase tungsten bronze structure in space group P4/mbm was obtained for all the compositions. Both the dielectric constant (ε′) and the dielectric loss (tan δ) exhibited a broad maximum with evident frequency dispersion far below room temperature, which indicated the typical relaxor nature. The selected area electron diffraction patterns revealed that the relaxor behavior in the present system originated from the incommensurate structure modulation. The dark-field transmission electron microscopy images confirmed the presence of polar nanoregions in the areas generating the satellite reflections of incommensurate structure modulation, which implied a possible correlation between the incommensurate structure modulation and polar nanoregions in tungsten bronze relaxors.
Dynamics of aqueous ferrofluid droplets at coflowing liquid-liquid interface under a non-uniform magnetic field
Authors: Banerjee U. , Raj A. , Sen A. K.
Published: October 2018

We report the dynamical behaviour of aqueous ferrofluid droplets (FFDs) of different sizes and concentrations at the interface of coflowing immiscible oils in a microchannel in the presence of the magnetic field. We show that the migration and sorting phenomena are governed by the interplay between magnetic force Fm, non-inertial lift force Fl, and interfacial tension force Fi. Depending on the force ratios, namely, the lift force ratio [KL=Fl/Fi] and magnetic force ratio [KM=Fm/Fi], three different regimes are identified. The results also reveal that the FFD trajectory and migration length (Lmig*) depend on the net force ratio [FR, net=Fm+Fl/Fi] and magnet location xm*. Finally, size-based sorting of FFD is demonstrated, which shows a remarkable improvement in terms of the size range and resolution compared to when the magnetic field is not present.
Small amplitude oscillations of a shape-morphing plate immersed in a viscous fluid near a solid wall
Authors: Ahsan Syed N. , Aureli Matteo
Published: October 2018

In this paper, we investigate small amplitude oscillations of a thin shape-morphing plate submerged in a quiescent, Newtonian, incompressible, viscous fluid in the vicinity of a solid wall. The plate undergoes prescribed, time-varying shape-morphing deformation in phase with the transverse oscillation, consisting of periodic curvature to an arc of a circle. As the presence of the solid wall in close proximity of the oscillating plate is known to significantly increase hydrodynamic damping on the structure due to squeeze film effects, shape-morphing is considered as a potential strategy to modulate and control hydrodynamic forces, as well as power dissipation. Via a rigorous formulation based on unsteady Stokes equations and the boundary element method, we show that the shape-morphing strategy is effective in reducing hydrodynamic forces on the structure as well as hydrodynamic power dissipation due to viscous effects. Additionally, such a reduction is enhanced as the gap between the oscillating plate and the solid wall is reduced. We present a comprehensive parametric study which investigates the effect of oscillation frequency, gap size, and imposed curvature on the hydrodynamic performance of the system and support our findings with asymptotics from inviscid flow theory and lubrication theory. These findings are of direct interest and applicability in several cantilever-based sensing and actuation systems, such as atomic force microscopy and microelectromechanical systems in liquids.
Commutation relations of vertex operators for Uq(sl^(M|N))
Authors: Kojima Takeo
Published: October 2018

We consider commutation relations and invertibility relations of vertex operators for the quantum affine superalgebra Uq(sl^(M|N)) by using bosonization. We show that vertex operators give a representation of the graded Zamolodchikov-Faddeev algebra by direct computation. Invertibility relations of type-II vertex operators for N > M are very similar to those of type-I for M > N.
Asymptotic stability for spectrally stable Lugiato-Lefever solitons in periodic waveguides
Authors: Stanislavova Milena , Stefanov Atanas G.
Published: October 2018

We consider the Lugiato-Lefever model of optical fibers in the periodic context. Spectrally stable periodic steady states were constructed recently in the studies of Delcey and Haragus [Philos. Trans. R. Soc., A 376, 20170188 (2018)]; [Rev. Roumaine Math. Pures Appl. (to be published)]; and Hakkaev et al. (e-print arXiv:1806.04821). The spectrum of the linearization around such solitons consists of simple eigenvalues 0, −2α < 0, while the rest of it is a subset of the vertical line {μ:Rμ=−α}. Assuming such a property abstractly, we show that the linearized operator generates a C0 semigroup and, more importantly, the semigroup obeys (optimal) exponential decay estimates. Our approach is based on the Gearhart-Prüss theorem, where the required resolvent estimates may be of independent interest. These results are applied to the proof of asymptotic stability with phase of the steady states.