bluuebunny/crossref_metadata_2025 huggingface dataset:
Response of unconfined turbidity current to relay‐ramp topography: insights from process‐based numerical modelling
Authors: Ge Zhiyuan , Nemec Wojciech , Gawthorpe Rob L. , Rotevatn Atle , Hansen Ernst W. M.
Published: July 2017

This natural‐scale experimental study combines structural modelling of soft‐linked normal‐fault relays with a CFD (computational fluid dynamics) numerical simulation of a range of unconfined turbidity currents overrunning the relay‐system topography. The flow, released from an upslope inlet gate 2000‐m wide and 50‐m to 100‐m high, rapidly expands and adjusts its thickness, velocity and sediment load to the substrate slope of 1.5°. A lower initial sediment concentration or smaller thickness renders the quasi‐steady flow slower and its sediment‐transport capacity lower. A 3D pattern of large interfering Kelvin‐Helmholtz waves causes fluctuations of the local flow velocity magnitude and sediment concentration. Four zones of preferential sediment deposition are recognized: a near‐gate zone of abrupt flow expansion and self‐regulation; a flow‐transverse zone on the counter‐slope of fault footwall edges; a flow‐transverse zone at the fault‐scarp toes and a similar transverse zone near the crest of the hanging wall counter‐slopes. The sand deposited on the counter‐slope tends to be re‐entrained and fed back to the current by a secondary reverse underflow. The spatial extent and sediment accumulation capacity of depozones depend upon the released current volume. The impact of relay system on an overrunning current depends upon the fault separation distance and stage of tectonic evolution. An early‐stage relay system, with small vertical displacement and little overlap of faults, is bypassed by the current with minimum flow disturbance and no pronounced deposition. An advanced‐stage system, with greater fault displacement and overlap, gives a similar hydraulic effect as a single fault segment if the fault separation is small. If the separation is relatively large, the flow tends to be internally redirected sideways from the ramp into the hanging wall synclinal depressions. Since normal‐fault relays are common features in extensional basins, the study bears important implications for turbiditic slope‐fan models and for the spatial sand prediction in subsurface exploration of faulted submarine slopes.
Assessment of colorectal length using the electromagnetic capsule tracking system: a comparative validation study in healthy subjects
Authors: Mark E. B. , Poulsen J. L. , Haase A. M. , Frøkjær J. B. , Schlageter V. , Scott S. M. , Krogh K. , Drewes A. M.
Published: July 2017

Aim

We aimed to determine colorectal length with the 3D‐Transit system by describing a ‘centreline’ of capsule movement and comparing it with known anatomy, as determined by magnetic resonance imaging (MRI). Further, we aimed to test the day‐to‐day variation of colorectal length assessed with the system.

Method

The 3D‐Transit system consists of electromagnetic capsules that can be tracked as they traverse the gastrointestinal tract. Twenty‐five healthy subjects were examined with both 3D‐Transit and MRI. Another 21 healthy subjects were examined with 3D‐Transit on two consecutive days.

Results

Computation of colorectal length from capsule passage was possible for 60 of the 67 3D‐Transit recordings. The length of the colorectum measured with MRI and 3D‐Transit was 95 (75–153) cm and 99 (77–147) cm, respectively (P = 0.15). The coefficient of variation (CV) between MRI and 3D‐Transit was 7.8%. Apart from the caecum/ascending colon being 26% (P = 0.002) shorter on MRI, there were no other differences in total or segmental colorectal lengths between methods (all P > 0.05). The length of the colorectum measured with 3D‐Transit on two consecutive days was 102 (73–119) cm and 103 (75–123) cm (P = 0.67). The CV between days was 7.3%.

Conclusion

The 3D‐Transit system allows accurate and reliable determination of colorectal length compared with MRI‐derived colorectal length and between days. Antegrade or retrograde capsule movement relative to this centreline, as well as the length and speed of movements, may be determined by future studies to allow better classification and treatment in patients with dysmotility.
The use of porcine urinary bladder matrix (UBM) to repair a perforated corneal ulcer with iris prolapse in a horse
Authors: Davis A. M. , Riggs C. M. , Chow D. W. Y.
Published: July 2017

This report describes the use of porcine urinary bladder matrix (UBM) to repair a full thickness defect in the cornea of a Thoroughbred racehorse. The horse presented with acute keratomalacia of the right eye of 12 h duration that had rapidly progressed to perforation of the cornea with partial iris prolapse. The cornea was surgically debrided with the horse under general anaesthesia and the defect repaired withACell multilayer wound matrix. A temporary tarsorrhaphy was performed. The defect in the cornea was successfully repaired and the horse regained vision in the eye. Four months after surgery the defect was still undergoing remodelling and the area of opacity in the cornea was progressively reducing.
Aspiration pneumonitis (Mendelson's syndrome) as perianaesthetic complication occurring in two horses: A case report
Authors: Monticelli P. , Adami C.
Published: July 2017

No published reports on the occurrence of Mendelson's syndrome (pneumonitis caused by aspiration during anaesthesia) in horses were found in the literature. Although the peculiar anatomy of the equine stomach makes horses less prone than other species to regurgitate, gastric reflux may still occur in horses with colic under certain circumstances. The colic horses in this report had in common stomach impaction, abdominal distention and preanaesthetic placement of a nasogastric tube, which was not withdrawn prior to induction. In both cases, a significant volume of gastric reflux was noted pouring from the endotracheal tube during general anaesthesia for exploratory laparotomy. It was hypothesised that the cause of gastric reflux was the combination of increased intra‐abdominal pressure and patency of the cardia, and that inhalation of gastric content occurred at induction, before tracheal intubation. Treatment, which failed to improve oxygenation, consisted of repositioning of the horses to facilitate passive drainage of gastric content from the airways, active suction through the endotracheal tubes, ventilation strategies, improvement of haemodynamics to increase the pulmonary perfusion, and administration of bronchodilators. One horse was subjected to euthanasia owing to poor prognosis. Aspiration pneumonitis should be regarded as a life‐threatening, although rare, perianaesthetic complication in equine colic cases. Patency of the cardia and increased intra‐abdominal pressure are possible predisposing factors. Partial or even total withdrawal of the nasogastric tube prior to anaesthetic induction and tracheal intubation performed with the horse positioned in sternal recumbency may be undertaken as preventive measures in patients at high risk of developing Mendelson's syndrome.
Renal vein dilation predicts poor outcome in patients with refractory cirrhotic ascites
Authors: Matsumoto Naoki , Ogawa Masahiro , Kumagawa Mariko , Watanabe Yukinobu , Hirayama Midori , Miura Takao , Nakagawara Hiroshi , Matsuoka Shunichi , Moriyama Mitsuhiko , Fujikawa Hirotoshi
Published: July 2017

Aim

Renal venous hypertension is known to be associated with worsening of renal function in patients with decompensated heart failure. Intra‐abdominal hypertension including cirrhotic ascites also leads to renal venous hypertension. We aimed to clarify the effect of renal venous hypertension on cirrhotic ascites.

Methods

Two hepatologists measured the left renal vein diameter in 142 consecutive patients with refractory cirrhotic ascites using non‐contrast computed tomography. The renal vein diameter was measured at the renal vein main trunk and upstream of the confluence of collateral veins.

Results

The inter‐observer agreements were high for the measurements of the left renal vein (r = 0.918, P < 0.001). The median overall survival for patients with renal vein diameter ≥11 mm was less than that for patients with renal vein diameter <11 mm (P < 0.001; 2.5 vs. 32.0 months). One‐year survival rates were 15.3% versus 66.4%. Multivariate analysis revealed renal vein diameter ≥11 mm (hazard ratio, 2.94; P < 0.001; 95% confidence interval, 1.67–5.20) and a high Model for End‐stage Liver Disease score combined with serum sodium level (MELD‐Na) (hazard ratio, 3.39; P < 0.001; 95% confidence interval, 2.00–5.74) were significant independent predictors of mortality.

Conclusions

Renal vein dilation is a risk factor of mortality in patients with refractory cirrhotic ascites, independent of the MELD‐Na score.
Effects of mesiodens on adjacent permanent teeth: a retrospective study in Korean children based on cone‐beam computed tomography
Authors: Kim Yuhyun , Jeong Taesung , Kim Jiyeon , Shin Jonghyun , Kim Shin
Published: July 2017

Background

Mesiodens can be associated with several complications. The optimal age for treatment, however, remains controversial.

Aim

To investigate the three‐dimensional (3D) positions of mesiodens using cone‐beam computed tomography (CBCT) and determine the association of eruption‐related complications of mesiodens with these 3D positions and delayed development of the central incisors.

Design

In total, 293 Korean children (383 supernumerary teeth) aged 4–10 years with no history of orthodontic treatment were included. CBCT and panoramic radiography data for all patients were retrospectively investigated with regard to the 3D positions of mesiodens, apical maturity of the permanent first molars, delayed development of the central incisors relative to the apical maturity of the permanent first molars (Nolla's stage), and eruption‐related complications of mesiodens.

Results

Eruption‐related complications were not correlated with any 3D characteristic other than the ‘within the arch’ position of mesiodens, while they showed a significant correlation with delayed development of the central incisors (P < 0.05).

Conclusions

Mesiodens caused eruption‐related complications in 33.7% patients. Moreover, the risk of these complications was higher when mesiodens caused delayed development of the central incisors. These findings can aid clinicians in planning appropriate and timely treatment for mesiodens, with focus on minimising patient discomfort.
Infection with influenza A(H1N1)pdm09 during the first wave of the 2009 pandemic: Evidence from a longitudinal seroepidemiologic study in Dhaka, Bangladesh
Authors: Nasreen Sharifa , Rahman Mustafizur , Hancock Kathy , Katz Jacqueline M. , Goswami Doli , Sturm‐Ramirez Katharine , Holiday Crystal , Jefferson Stacie , Branch Alicia , Wang David , Veguilla Vic , Widdowson Marc‐Alain , Fry Alicia M. , Brooks W. Abdullah
Published: July 2017

Background

We determined influenza A(H1N1)pdm09 antibody levels before and after the first wave of the pandemic in an urban community in Dhaka, Bangladesh.

Methods

We identified a cohort of households by stratified random sampling. We collected baseline serum specimens during July‐August 2009, just prior to the initial wave of the 2009 pandemic in this community and a second specimen during November 2009, after the pandemic peak. Paired sera were tested for antibodies against A(H1N1)pdm09 virus using microneutralization assay and hemagglutinin inhibition (HI) assay. A fourfold increase in antibody titer by either assay with a titer of ≥40 in the convalescent sera was considered a seroconversion. At baseline, an HI titer of ≥40 was considered seropositive. We collected information on clinical illness from weekly home visits.

Results

We tested 779 paired sera from the participants. At baseline, before the pandemic wave, 1% overall and 3% of persons >60 years old were seropositive. After the first wave of the pandemic, 211 (27%) individuals seroconverted against A(H1N1)pdm09. Children aged 5‐17 years had the highest proportion (37%) of seroconversion. Among 264 (34%) persons with information on clinical illness, 191 (72%) had illness >3 weeks prior to collection of the follow‐up sera and 73 (38%) seroconverted. Sixteen (22%) of these 73 seroconverted participants reported no clinical illness.

Conclusion

After the first pandemic wave in Dhaka, one in four persons were infected by A(H1N1)pdm09 virus and the highest burden of infection was among the school‐aged children. Seroprevalence studies supplement traditional surveillance systems to estimate infection burden.
A simple synthesis of the refractory ceramic sulfide CeS by electron beam irradiation
Authors: Panetta Riccardo , Latini Alessandro
Published: July 2017

A new, relatively fast and simple synthesis of the refractory sulfide CeS using electron beam irradiation has been developed. Differently from the most common procedures involving highly reactive and/or toxic precursors such as cerium hydride and carbon disulfide, the approach here presented is based on the electron beam irradiation of pellets composed of a mixture of cerium sesquisulfide, cerium dioxide and graphite powders, i.e., nontoxic and nonreactive materials in ambient conditions that do not need any special caution during their use. CeS with a purity ≥98 wt% has been obtained, being Ce2O2S the impurity and whose amount can be lowered by annealing on a graphite surface.
Structure and conductivity of yttria and scandia‐doped zirconia crystals grown by skull melting
Authors: Borik Mihail A. , Bredikhin Sergey I. , Bublik Vladimir T. , Kulebyakin Aleksej V. , Kuritsyna Irina E. , Lomonova Elena E. , Milovich Philipp O. , Myzina Valentina A. , Osiko Vyacheslav V. , Ryabochkina Polina A. , Tabachkova Nataliya Y.
Published: July 2017

In this paper a detailed study of the (ZrO2)1‐x(Y2O3)x (x=0.025–0.15), (ZrO2)1‐x(Sc2O3)x (x = 0.06 – 0.11) and (ZrO2)1‐x‐y(Sc2O3)x(Y2O3)y (x=0.07 – 0.11; y=0.01 – 0.04) solid solution crystals grown by skull melting technique is presented. The structure, phase composition, and ion conductivity of the obtained crystals were investigated by X‐ray diffraction, transmission electron microscopy, Raman scattering spectroscopy, and impedance spectroscopy. Maximum conductivity as (ZrO2)1‐x(Y2O3)x and (ZrO2)1‐x(Sc2O3)x solid solution crystals is observed for the compositions containing 10 mol% stabilizing oxide, and the conductivity of 10ScSZ is ~3 times higher than for 10YSZ. Experiments on crystal growth (ZrO2)1‐x‐y(Sc2O3)x(Y2O3)y solid solutions showed that uniform, transparent crystals 7Sc3YSZ, 7Sc4YSZ, 8Sc2YSZ, 8Sc3YSZ, 9Sc2YSZ, 9Sc3YSZ, 10Sc1YSZ, and 10Sc2YSZ are single phase crystal containing t″ phase. It is established that a necessary condition of melt growth of (ZrO2)1‐x‐y(Sc2O3)x(Y2O3)y single‐phase crystals is the total concentration of the stabilizing oxides from 10 to 12 mol%. The addition of Y2O3 affects the (ZrO2)1‐x‐y(Sc2O3)x(Y2O3)y solid solution conductivity different ways and depends on the Sc2O3 content in the starting composition. The effects of structure, phase composition, concentration, and type of stabilizing oxides on the electrical characteristics of obtained crystals are discussed.
Defective Y2O3−x–driven anomalous photocatalytic enhancement using Y2O3−x–TiO2−x nanorod composite composition spreads
Authors: Rosell Neon Vicente Bacarro , Chen Yen‐Ting , Chang Kao‐Shuo
Published: July 2017

Synergistic photocatalysis is reported, using the optimal amounts of oxygen vacancies of high‐k materials and nanoarchitecture maneuvering by employing a combinatorial sputtering approach. The highlights include (i) the successful fabrication of samples using combinatorial sputtering; (ii) a systematic investigation of the coupling effect between Y2O3−x and TiO2−x; (iii) elucidating charge carrier transport through current‐voltage (I‐V) and capacitance‐voltage (C‐V) characterizations; and (iv) providing an alternative application for high‐dielectric constant (high‐k) materials in photocatalysis. The simple yet effective composition spread technique rapidly determined that Sample 6 (4 at% Y2O3−x‐96 at% TiO2−x, TiO2−x‐rich on the Y2O3−x–TiO2−x nanorod composite composition spread) exhibited the highest photocatalytic efficiency (i.e., approximately 3.4 times and 1.4 times higher than that of P25 and pure TiO2−x nanorods, respectively). The predominant factor was determined to be electron migration along defective Y2O3−x nanorods to the sample surface. The extracted mobility was discovered to be an order of magnitude greater than that of pure TiO2−x. The photoelectrochemical stability and reusability were also demonstrated.
Contrasting patterns of X‐chromosome divergence underlie multiple sex‐ratio polymorphisms in stalk‐eyed flies
Authors: Paczolt K. A. , Reinhardt J. A. , Wilkinson G. S.
Published: July 2017

Sex‐linked segregation distorters cause offspring sex ratios to differ from equality. Theory predicts that such selfish alleles may either go to fixation and cause extinction, reach a stable polymorphism or initiate an evolutionary arms race with genetic modifiers. The extent to which a sex ratio distorter follows any of these trajectories in nature is poorly known. Here, we used X‐linked sequence and simple tandem repeat data for three sympatric species of stalk‐eyed flies (Teleopsis whitei and two cryptic species of T. dalmanni) to infer the evolution of distorting X chromosomes. By screening large numbers of field and recently laboratory‐bred flies, we found no evidence of males with strongly female‐biased sex ratio phenotypes (SR) in one species but high frequencies of SR males in the other two species. In the two species with SR males, we find contrasting patterns of X‐chromosome evolution. T. dalmanni‐1 shows chromosome‐wide differences between sex‐ratio (XSR) and standard (XST) X chromosomes consistent with a relatively old sex‐ratio haplotype based on evidence including genetic divergence, an inversion polymorphism and reduced recombination among XSR chromosomes relative to XST chromosomes. In contrast, we found no evidence of genetic divergence on the X between males with female‐biased and nonbiased sex ratios in T. whitei. Taken with previous studies that found evidence of genetic suppression of sex ratio distortion in this clade, our results illustrate that sex ratio modification in these flies is undergoing recurrent evolution with diverse genomic consequences.
Novel ex vivo training model for freehand insertion using a double‐bending peroral direct cholangioscope
Authors: Naito Sakiko Tsukamoto , Itoi Takao , Yamamoto Kenjiro , Tsuchiya Takayoshi , Tsuji Shujiro , Tanaka Reina , Honjo Mitsuyoshi , Mukai Shuntaro , Matsunami Yukitoshi , Asai Yasutsugu , Nagakawa Yuichi , Ikeuchi Nobuhito , Sofuni Atsushi
Published: July 2017

Background and Aim

Several experts of direct peroral videocholangioscopy (D‐PVCS) using a conventional ultraslim endoscope have reported its usefulness for the diagnosis and therapy of biliary tract diseases. We have additionally developed a dedicated double‐bending D‐PVCS technique for freehand scope insertion. In this study, we developed an ex vivo training model for the freehand double‐bending D‐PVCS technique and compared it with the technique using a conventional ultraslim endoscope.

Methods

The ex vivo model was made for training using a U‐shape insertion pattern. A third prototype endoscope and an ultraslim upper gastrointestinal endoscope were used. Two experts and nine non‐experts performed D‐PVCS using the freehand technique.

Results

The two experts could not advance the tip of the endoscope to the hilar portion using the freehand technique, but they could achieve technical successful insertion to the hilar portion with the third prototype cholangioscope using the freehand technique alone. The non‐experts could not advance the tip of the endoscope to the bile duct using the freehand technique. On the other hand, two (22.2%) non‐experts could advance the tip of the third prototype cholangioscope using the freehand technique before the training conducted by the experts. After the training, all the non‐experts could advance the tip of the third prototype cholangioscope to the hilar portion.

Conclusions

The novel ex vivo model using a third prototype cholangioscope was useful for training in the use of the freehand D‐PVCS technique.
Intussusception in celiac disease: Is it a common feature in children?
Authors: Borkar Vibhor V , Poddar Ujjal , Thakral Anuj , Agarwal Jaya , Srivastava Anshu , Yachha Surender Kumar , Kumar Sheo
Published: July 2017

Background and Aim

There are sporadic reports of occurrence of intussusception in celiac disease (CD) but no systematic study yet. We prospectively studied the prevalence and natural history of intussusception in newly diagnosed CD.

Methods

From January 2010 to October 2013, 150 children, diagnosed to have CD on the basis of positive serology and duodenal biopsy, were recruited in this study. Abdominal ultrasonography was carried out before starting gluten‐free diet (GFD) and repeated in those who had intussusception, on day 3 and then weekly till the resolution of intussusception.

Results

The median age was 72 (range, 16–204) months, and 79 (53%) were boys. Diarrhea was the presenting symptom in 119 (79%) cases. A total of 45 intussusceptions were detected in 37 (25%) children. Out of 45 intussusceptions, 95% involved small bowel. All but one had asymptomatic intussusception. On GFD, intussusception resolved spontaneously within 7 days in 65%, within 14 days in 84%, and within 28 days in 92% of cases, and none required surgical or hydrostatic reduction. On univariate analysis, younger age, low weight z score, presentation with diarrhea, abdominal distension, rickets, lower serum albumin, more severe villous atrophy, and refeeding syndrome were more common in children with intussusception. On multivariate analysis, abdominal distension and hypoalbuminemia were found to be significantly associated with intussusception.

Conclusions

Intussusception is frequently (25%) seen in children with newly diagnosed CD, generally asymptomatic and resolves spontaneously on GFD. It is often associated with more severe disease. Children with CD and intussusception should not be subjected to surgical/radiological intervention.
Presidential Address: The Scientific Outlook in Financial Economics
Authors: HARVEY CAMPBELL R.
Published: July 2017

Given the competition for top journal space, there is an incentive to produce “significant” results. With the combination of unreported tests, lack of adjustment for multiple tests, and direct and indirect p‐hacking, many of the results being published will fail to hold up in the future. In addition, there are basic issues with the interpretation of statistical significance. Increasing thresholds may be necessary, but still may not be sufficient: if the effect being studied is rare, even t > 3 will produce a large number of false positives. Here I explore the meaning and limitations of a p‐value. I offer a simple alternative (the minimum Bayes factor). I present guidelines for a robust, transparent research culture in financial economics. Finally, I offer some thoughts on the importance of risk‐taking (from the perspective of authors and editors) to advance our field.

Empirical research in financial economics relies too much on p‐values, which are poorly understood in the first place.

Journals want to publish papers with positive results and this incentivizes researchers to engage in data mining and “p‐hacking.”

The outcome will likely be an embarrassing number of false positives—effects that will not be repeated in the future.

The minimum Bayes factor (which is a function of the p‐value) combined with prior odds provides a simple solution that can be reported alongside the usual p‐value.

The Bayesianized p‐value answers the question: What is the probability that the null is true?

The same technique can be used to answer: What threshold of t‐statistic do I need so that there is only a 5% chance that the null is true?

The threshold depends on the economic plausibility of the hypothesis.
Incidence, predictive factors and impacts of acute kidney injury in cirrhotic patients hospitalized for cellulitis
Authors: Garcia Garcia de Paredes Ana , Tellez Luis , Rodriguez‐Gandia Miguel Angel , Martinez Javier , Rodriguez de Santiago Enrique , Aguilera Castro Lara , Gea Francisco , Albillos Agustín
Published: July 2017

Background & Aims

Cellulitis is a common infection in patients with cirrhosis but its impact on progression of liver disease has been hardly addressed. This study examines the incidence of acute kidney injury (AKI), predictive factors and its impacts on mortality in cirrhotic patients hospitalized for cellulitis.

Methods

Retrospective data from cirrhotic patients hospitalized for cellulitis over the period January 2006 to September 2015 were analysed. AKI was defined according to revised criteria of the International Club of Ascites.

Results

A total of 101 episodes of cellulitis were examined (70.3% men; mean age 60.6 ± 13.6 years). Of patients, 27% met criteria for acute on chronic liver failure (ACLF) (grade 1: 63%; grade 2: 22%; grade 3: 15%). AKI was recorded in 50.5% (type 1: 67%; type 2: 19%; type 3: 14%). AKI was present on admission in 21 of the 51 patients (41%) who developed it. In the remaining 30 patients (59%), AKI appeared during hospitalization and its development was associated with a MELD score >14 (70% vs 30%, P=.024). In‐hospital mortality was 10% and all patients who died had AKI. A high MELD score on admission, AKI and ACLF were associated with in‐hospital mortality (P<.05). One‐month transplant‐free survival was 84% (70% vs 98% in patients with and without AKI, P=.001).

Conclusions

In cirrhotic patients, cellulitis is a serious infection that often leads to AKI and ACLF. AKI is a strong predictor of mortality in this setting.
Manufacturer Rebate Competition in a Supply Chain with a Common Retailer
Authors: Ha Albert Y. , Shang Weixin , Wang Yunjie
Published: July 2017

We consider manufacturer rebate competition in a supply chain with two competing manufacturers selling to a common retailer. We fully characterize the manufacturers’ equilibrium rebate decisions and show how they depend on parameters such as the fixed cost of a rebate program, market size, the redemption rate of rebate, the proportion of rebate‐sensitive consumers in the market and competition intensity. Interestingly, more intense competition induces a manufacturer to lower rebate value or stop offering rebate entirely. Without rebate, it is known that more intense competition hurts the manufacturers and benefits the retailer. With rebate, however, more intense competition could benefit the manufacturers and hurt the retailer. We find similar counterintuitive results when there is a change in some other parameters. We also consider the case when the retailer subsidizes the manufacturers sequentially to offer rebate programs. We fully characterize the retailer's optimal subsidy strategy, and show that subsidy always benefits the retailer but may benefit or hurt the manufacturers. When the retailer wants to induce both manufacturers to offer rebate, he always prefers to subsidize the manufacturer with a higher fixed cost first. Sometimes the other manufacturer will then voluntarily offer rebate even without subsidy.
Mitigating Inventory Overstocking: Optimal Order‐up‐to Level to Achieve a Target Fill Rate over a Finite Horizon
Authors: Tan Yinliang (Ricky) , Paul Anand A. , Deng Qi , Wei Lai
Published: July 2017

Service level agreements (SLAs) are widely adopted performance‐based contracts in operations management practice, and fill rate is the most common performance metric among all the measurements in SLAs. Traditional procedures characterizing the order‐up‐to level satisfying a specified fill rate implicitly assume an infinite performance review horizon. However, in practice, inventory managers are liable to maintain and report fill rates over a finite performance review horizon. This horizon discrepancy leads to deviation between the target fill rate and actual achieved fill rate. In this study, we first examine the behavior of the fill rate distribution over a finite horizon with positive lead time. We analytically prove that the expected fill rate assuming an infinite performance review horizon exceeds the expected fill rate assuming a finite performance review horizon, implying that there exists some inventory “waste” (i.e., overstocking) when the traditional procedure is used. Based on this observation and the complexity of the problem, we propose a simulation‐based algorithm to reduce excess inventory while maintaining the contractual target fill rate. When the lead time is significant relative to the length of the contract horizon, we show that the improvement in the inventory system can be over 5%. Further, we extend our basic setting to incorporate the penalty for failing to meet a target, and show how one can solve large‐scale problems via stochastic approximation. The primary managerial implication of our study is that ignoring the performance review horizon in an SLA will cause overstocking, especially when the lead time is large.
Coordinating Supply Chains via Advance‐Order Discounts, Minimum Order Quantities, and Delegations
Authors: Chintapalli Prashant , Disney Stephen M. , Tang Christopher S.
Published: July 2017

To avoid inventory risks, manufacturers often place rush orders with suppliers only after they receive firm orders from their customers (retailers). Rush orders are costly to both parties because the supplier incurs higher production costs. We consider a situation where the supplier's production cost is reduced if the manufacturer can place some of its order in advance. In addition to the rush order contract with a pre‐established price, we examine whether the supplier should offer advance‐order discounts to encourage the manufacturer to place a portion of its order in advance, even though the manufacturer incurs some inventory risk. While the advance‐order discount contract is Pareto‐improving, our analysis shows that the discount contract cannot coordinate the supply chain. However, if the supplier imposes a pre‐specified minimum order quantity requirement as a qualifier for the manufacturer to receive the advance‐order discount, then such a combined contract can coordinate the supply chain. Furthermore, the combined contract enables the supplier to attain the first‐best solution. We also explore a delegation contract that either party could propose. Under this contract, the manufacturer delegates the ordering and salvaging activities to the supplier in return for a discounted price on all units procured. We find the delegation contract coordinates the supply chain and is Pareto‐improving. We extend our analysis to a setting where the suppliers capacity is limited for advance production but unlimited for rush orders. Our structural results obtained for the one‐supplier‐one‐manufacturer case continue to hold when we have two manufacturers.
Comparative analysis of pathogenic and nonpathogenic Fusarium oxysporum populations associated with banana on a farm in Minas Gerais, Brazil
Authors: Deltour P. , França S. C. , Heyman L. , Pereira O. L. , Höfte M.
Published: July 2017

Fusarium wilt is one of the most devastating diseases on banana. The causal agent, Fusarium oxysporum f. sp. cubense (Foc) is genetically diverse and its origin and virulence are poorly understood. In this study, pathogenic Foc isolates and nonpathogenic F. oxysporum isolates from Minas Gerais in Brazil were compared using EF‐1α and IGS sequences. This allowed the examination of the origin and evolutionary potential of Foc in a country outside the region of origin of the banana plant. Two different sequence types were found among Foc isolates. One appeared to be of local origin because it was identical to the sequence type of the largest group of nonpathogenic isolates. To explore if the ‘local’ Foc isolates had acquired pathogenicity either independently through coevolution with the host, or through horizontal gene transfer (HGT) of pathogenicity genes from other, probably introduced, Foc isolates, the presence and sequence of putative SIX effector genes were analysed. Homologues of SIX1, SIX3 and SIX8 were found. SIX1 sequences were identical and exclusively found in all pathogenic isolates, while variable ratios of sequences of multicopy gene SIX8 were found among nonpathogenic and different pathogenic isolates. This observation supports the HGT hypothesis. Horizontal transfer of genes between isolates of F. oxysporum has important implications for the development of reliable diagnostic tools and effective control measures. Full genome sequencing is required to confirm HGT and to further unravel the virulence mechanisms of forma specialis cubense.
Influence of orthopedic reinforced gloves versus double standard gloves on contamination events during small animal orthopedic surgery
Authors: Hayes Galina , Singh Ameet , Gibson Tom , Moens Noel , Oblak Michelle , Ogilvie Adam , Reynolds Debbie
Published: July 2017

Objective

To determine the influence of orthopedic reinforced gloves on contamination events during small animal orthopedic surgery.

Study design

Prospective randomized controlled trial

Sample population

Two hundred and thirty‐seven pairs of orthopedic gloves (474 gloves) and 203 pairs of double standard gloves (812 gloves) worn during 193 orthopedic procedures.

Methods

Primary and assistant surgeons were randomized to wear either orthopedic reinforced gloves or double gloves. Gloves were leak tested to identify perforations at the end of procedures. Perforations detected intraoperatively or postoperatively were recorded. A contamination event was defined as at least one perforation on either hand for orthopedic reinforced gloves, or a perforation of both the inner and outer glove on the same hand for double gloves.

Results

Baseline characteristics between the 2 intervention groups were similar. There was no difference in contamination events between the double‐gloved and orthopedic gloved groups (OR = 0.95, 95% CI = 0.49‐1.87,P = .89). The same percentage of contamination events (8% glove pairs used) occurred in the double gloved group (17 contamination events) and in the orthopedic gloved group (19 contamination events). The odds of a contamination event increased by 1.02 (95% CI 1.01‐1.03,P < .001) with each additional minute of surgery.

Conclusion

Orthopedic reinforced gloves and double standard gloving were equally effective at preventing contamination events in small animal orthopedic procedures.

Clinical relevance

Surgeons reluctant to double glove due to perceptions of decreased dexterity and discomfort may safely opt for wearing orthopedic gloves, which may improve their compliance.
Numerical Heat Transfer and Entropy Analysis on Liquid Slip Flows Through Parallel-Plate Microchannels
Authors: Shojaeian Mostafa , Nedaei Masoumeh , Yildiz Mehmet , Koşar Ali
Published: July 2017

In this study, two-dimensional (2D) numerical simulations of liquid slip flows in parallel-plate microchannels have been performed to obtain heat transfer characteristics and entropy generation rate under asymmetric heating conditions. Heat transfer analysis has been conducted along with second-law analysis through utilizing temperature-dependent thermophysical properties. The results indicate that temperature-dependent thermophysical properties have a positive effect on convective heat transfer and entropy generation. Nusselt numbers of the upper and lower plates and global entropy generation rates are significantly affected by slip parameter and heat flux ratio. It is shown that Nusselt number of the lower plate may have very large but finite values at a specific heat flux ratio. This finding resembles to analytical solutions, where singularities leading to an infinite Nusselt number exist.
Convective Heat Transfer Enhancement Using Ferrofluid: A Review
Authors: Singh Mehta Jaswinder , Kumar Rajesh , Kumar Harmesh , Garg Harry
Published: July 2017

Ferrofluids, a distinctive class of nanofluid, consists of suspension of magnetic nanoparticles in a nonmagnetic base fluid. Flow and heat transport properties of such a fluid can be manipulated when subjected to external magnetic field and temperature gradient. This unique feature has fascinated researchers across the globe to test its capability as a coolant for miniature electronic devices. The proposed work presents an updated and comprehensive review on ferrofluids with emphasis on heat transfer enhancement of microdevices. Based on the research findings, a number of important variables that have direct bearing on convective heat transport ability of ferrofluid have been recognized. The paper also identifies the key research challenges and opportunities for future research. By critically resolving these challenges, it is anticipated that ferrofluids can make substantial impact as coolant in miniature heat exchangers.
Developments in Nuclear Power and Radioactive Waste Management
Authors: Wong Kaufui V. , Dia Sarah
Published: July 2017

Currently occupying only a small portion of the energy sector, nuclear power is increasingly becoming a promising contender for energy resources of the future. With growing concern of climate change and excessive carbon emissions from fossil fuels, nuclear is widely being pursued as an alternative energy resource that does not produce carbon dioxide. Nuclear power has been the source of environmentally hazardous byproducts of its own, however, and issues with radioactive waste have in many ways halted progress in nuclear power development and implementation. New advances now attempt to solve the many issues of the past, associated mostly with nuclear fission. Some of these developments, including the promising use of nuclear fusion, are evaluated as a means of solving the energy crises as well as the radioactive waste issues.
Tailoring Charge Reactivity Using In-Cylinder Generated Reformate for Gasoline Compression Ignition Strategies
Authors: Ekoto Isaac W. , Wolk Benjamin M. , Northrop William F. , Hansen Nils , Moshammer Kai
Published: July 2017

In-cylinder reforming of injected fuel during a negative valve overlap (NVO) recompression period can be used to optimize main-cycle combustion phasing for low-load low-temperature gasoline combustion (LTGC). The objective of this work is to examine the effects of reformate composition on main-cycle engine performance. An alternate-fire sequence was used to generate a common exhaust temperature and composition boundary condition for a cycle-of-interest, with performance metrics measured for these custom cycles. NVO reformate was also separately collected using a dump-valve apparatus and characterized by both gas chromatography (GC) and photoionization mass spectroscopy (PIMS). To facilitate gas sample analysis, sampling experiments were conducted using a five-component gasoline surrogate (iso-octane, n-heptane, ethanol, 1-hexene, and toluene) that matched the molecular composition, 50% boiling point, and ignition characteristics of the research gasoline. For the gasoline, it was found that an advance of the NVO start-of-injection (SOI) led to a corresponding advance in main-period combustion phasing as the combination of longer residence times and lower amounts of liquid spray piston impingement led to a greater degree of fuel decomposition. The effect was more pronounced as the fraction of total fuel injected in the NVO period increased. Main-period combustion phasing was also found to advance as the main-period fueling decreased. Slower kinetics for leaner mixtures were offset by a combination of increased bulk-gas temperature from higher charge specific heat ratios and increased fuel reactivity due to higher charge reformate fractions.
On Convective Heat Transfer and Flow Dynamics Through a Straight T-Bifurcating Channel
Authors: Abdelhak Lakehal , Nora Nait-Bouda , Julien Pelle , Souad Harmand
Published: July 2017

Both experimental and numerical studies of a turbulent flow in a bifurcating channel are performed to characterize the dynamical behavior of the flow and its impact on the convective heat transfer on the sides of the branch. This configuration corresponds to the radial vents placed in the stator vertically to the rotor–stator air gap in the electrical machines. Indeed, our analysis focuses on the local convective heat transfer on the vents internal surface under a turbulent mass flow rate. The flow field measurements were carried out with two components particle image velocimetry (PIV) system, and the local heat transfer on the sides of the bifurcation branch was measured using an infrared thermography device. The convective heat transfer and the flow dynamics through the geometry are investigated numerically considering a three-dimensional (3D) flow. The closure system of the Navier–Stokes equations for steady and incompressible flow is based on the low-Reynolds numbers Reynolds stress model (RSM) (RSM-stress-ω). The comparison of the 3D computed results with the measurements in the xy symmetry plane is satisfactory in the vertical and horizontal channels. The numerical prediction of the secondary flow in the vertical branch was analyzed and complements the experimental results. It was particularly noticed that the accelerated flow observed at the right side of the branch's inlet allows more pronounced heat transfer comparatively to the left side. Beyond approximately 7 hydraulic diameters from the entrance of the branch, the Nusselt number curves on the two sides of the branch tend to be the same developed Nusselt number, Nud.
Numerical Estimation of Thermal Radiation Effects on Marangoni Convection of Dusty Fluid
Authors: Siddiqa Sadia , Begum Naheed , Hossain Md. Anwar , Al-Rashed Abdullah A. A. A.
Published: July 2017

In this paper, numerical solutions to thermally radiating Marangoni convection of dusty fluid flow along a vertical wavy surface are established. The results are obtained with the understanding that the dust particles are of uniform size and dispersed in optically thick fluid. The numerical solutions of the dimensionless transformed equations are obtained through straightforward implicit finite difference scheme. In order to analyze the influence of various controlling parameters, results are displayed in the form of rate of heat transfer, skin friction coefficient, velocity and temperature profiles, streamlines, and isotherms. It is observed that the variation in thermal radiation parameter significantly alters the corresponding particle pattern and extensively promotes the heat transfer rate.
Sliding Tribological Behavior of Al–Fe–V–Si–Graphite Solid-Lubricating Composites at Elevated Temperatures
Authors: Tan Hui , Wang Shuai , Cheng Jun , Zhu Shengyu , Yang Jun
Published: July 2017

Aluminum alloy metal matrix composites (Al-MMCs) have been considered as promising materials for aerospace and automotive industries due to their excellent balance of physical, mechanical, and tribological properties. In the present work, the Al–Fe–V–Si alloy matrix composites with 0–20 wt. % copper-coated graphite were fabricated by hot-pressed sintering. The dry sliding tests were carried out at various temperatures ranging from room temperature (RT) to 350 °C. The microstructure, phase, hardness, and worn surface of the sintered composites were examined in detail. The effect of copper-coated graphite amount on the properties of the composite was also investigated. The results show that the Al–Fe–V–Si–graphite composites mainly consist of α-Al, Al8Fe2Si intermetallic, and graphite phases. The addition of Cu-coated graphite can decrease the friction coefficient and wear rate from RT to 350 °C. The Al–Fe–V–Si–graphite composite containing 10 wt. % copper-coated graphite exhibits better wear properties than other composites. The favorable lubricating properties were attributed to the tribolayer with graphite lubricating film formed on the worn surface.
Identification of the Effective Control Parameter to Enhance the Progression Rate of Vibro-Impact Devices With Drift
Authors: Nguyen Van-Du , Ho Huu-Duc , Duong The-Hung , Chu Ngoc-Hung , Ngo Quoc-Huy
Published: July 2017

This paper presents an experimental study to find out an effective parameter which is useful to enhance the progression rate of drifting vibro-impact systems excited by a harmonic force. It is assumed that the system performance would be better if the excitation force stays in a harmonious relationship with the natural motion of the impact mass. This hypothesis has been numerically analyzed and then experimentally verified. The phase lag between the excitation force and the motion of the impact mass is used to identify the best situation, where the system progression rate is maximal. It has been found that the highest progression rate of the system can be obtained when the phase lag is around one-eighth of the excitation period.
A Review of the Rotordynamic Thermally Induced Synchronous Instability (Morton) Effect
Authors: Tong Xiaomeng , Palazzolo Alan , Suh Junho
Published: July 2017

The Morton effect (ME) is a thermally induced instability problem that most commonly appears in rotating shafts with large overhung masses and supported by fluid-film bearings. The time-varying thermal bow, due to the asymmetric journal temperature distribution, may cause intolerable synchronous vibrations that exhibit a hysteresis behavior with respect to rotor speed. First discovered by Morton in the 1970s and theoretically analyzed by Keogh and Morton in the 1990s, the ME is still not fully understood by industry and academia experts. Traditional rotordynamic analysis generally fails to predict the potential existence of ME-induced instability in the design stage or troubleshooting process, and the induced excessive rotor vibrations cannot be effectively suppressed through conventional balancing, due to the continuous fluctuation of vibration amplitude and phase angle. In recent years, a fast growing number of case studies of ME have sparked academic interest in analyzing the causes and solutions of ME, and engineers have moved from an initial trial and error approach to more research inspired modification of the rotor and bearing. To facilitate the understanding of ME, the current review is intended to give the most comprehensive summary of ME in terms of symptoms, causes, prediction theories, and solutions. Published case studies in the past are also analyzed for ME diagnosis based on both the conventional view of critical speed, separation margin (SM), and the more recent view of the rotor thermal bow and instability speed band shifting. Although no universal solutions of ME are reported academically and industrially, recommendations to help avoid the ME are proposed based on both theoretical predictions and case studies.