bluuebunny/crossref_metadata_2025 huggingface dataset:
Superficial Parotidectomy by Retrograde Facial Nerve Dissection
Authors: Gurung Narendra Vikram , Shrestha D , Acharya A , Gurung A , Shrestha S , Poudel SR , Chapagain A , Regmi SM
Published: August 2017

Introduction: Tumors of the salivary gland are relatively uncommon and represent less than two percentage of all head and neck neoplasms. Parotid gland tumor comprises 85% of the salivary gland tumors of which 80% are being benign. Superficial parotidectomy is the commonest procedure done for parotid tumors which can be performed by either anteretrograde or retrograde facial nerve dissection technique.Methods: Outcome of 60 patients after superficial parotidectomy with retrograde facial nerve dissection has been studied.Results: Total of 60 patients had been studied. Complications like facial nerve weakness, Freys syndrome, salivary fistula, and wound infection were taken into account. Among them, 13.33% patients developed temporary facial nerve weakness, followed by temporary salivary fistula, 1.6%. None of the patients developed any severe complication.Conclusion: Superficial parotidectomy by retrograde facial nerve dissection is an easy technique to carry out with low complication rate and without compromising surgical outcome.Journal of Gandaki Medical CollegeVol. 10, No. 1, 2017, page: 25-27
Medical Waste Storage Practice in Health Care Institutions of Pokhara Sub-metropolitan City
Authors: Baral Prakash , Banstola R , Nepal D , Baral P
Published: August 2017

Introduction: Medical wastes include all the waste generated by health care establishments, research facilities, and laboratories. Medi­cal waste is any waste that is generated in the diagnosis, treatment or immunization of human beings or animals, in research pertaining there to or in the productions or testing of biological culture.Methods: The fourteen numbers of health care institutions (HCIs) having inpatient facilities, were sampled for the study. After taking ob­servation, the collected information was entered into a computer. Basi­cally, the percentages, projection analysis, simple average, and scenario analysis were used as an analysis tools.Results: Out of the HCIs surveyed, only 21.43% of them had a separate room assigned for primary storage of all sorts of waste and remaining 78.57% of them had open storage facilities for un-segregated mass of waste nearby the incineration area or open burning area.Conclusion: There was lack of appropriate information on waste stor­age practices, and unaware of designing central storage system in HCIs. In most of the HCIs, a separate storage room was not assigned for stor­age of all sorts of waste.Journal of Gandaki Medical CollegeVol. 10, No. 1, 2017, page: 31-33
A Healthy City Project: A Case Study of Wonju City, South Korea and its Relevance to the Cities in Nepal
Authors: Sharma Bimala , Nam EW
Published: August 2017

Introduction: One of the goals of sustainable development is to make cities inclusive, safe, resilient and sustainable. The healthy city approach is becoming increasingly important in addressing a large number of urban health problems and promoting healthy lifestyles in city dwellers.Objectives: We performed a case study of the healthy city project in Wonju, South Korea to find out its characteristics and approaches, and to explore its relevance to the cities in Nepal.Methods: We conducted a case study of the healthy city Wonju project by reviewing relevant published articles and web pages of the city (http://healthycity.wonju.go.kr), alliance for healthy cities, Korean statistical information service and World Health Organization. We also reviewed articles and documents related to healthy cities in South-East Asian countries and Nepal.Results: The healthy city Wonju project, started in 2004, executed its five-year plan between 2006 and 2010, and is currently running with its 10 year long-term plan (2011- 2020). For its success, Wonju City has been awarded six times by WHO. Recently, Wonju city organized the seventh global conference of the AFHC in August, 2016 in Wonju with the main theme of “our cities, our health, our future”. Key features of the healthy city Wonju project included: Strong political commitment of local government, financing the healthy city initiative with tobacco consumption tax, partnerships with universities, well organized healthy city teams under city administration, coordination with national and regional healthy cities alliance, community participation, and involvement in research for evidence-based planning and evaluation. Nepal, one of the fast urbanizing countries in South-East Asia faces large number of urban health problems.Conclusions: Though numbers of cities and city dwellers are increasing rapidly, Nepal lacks healthy city projects and networking. The approaches of healthy city Wonju might be useful for developing countries such as Nepal to initiate and develop healthy cities projects in a sustainable way. Journal of Gandaki Medical CollegeVol. 10, No. 1, 2017, page: 34-42
Micro Health Project
Authors: Khadka Ajay , Sharma S , Regmi S , Chapagain S , Lamichhane B , Baral S , Thapa P , KC Ankur , Thapa A , Mandal B , Khadka P , Poudel A , Khanal S , Shrestha U
Published: August 2017

Community health diagnosis is a comprehensive assessment of health status of the community in relation to its social, physical and biological environment. The purpose of community health diagnosis is to define existing problems, determine available resources and set priorities for planning, implementing and evaluating health action, by and for the community. The community health diagnosis program began on 4th September 2015 and continued till 13th September 2015 in ward no 1 and 5 Rupakot VDC, Kaski, Nepal. The program was organized in following phases: data collection, data analysis, first community presentation, prioritization of need and planning of micro health project (MHP), implementation and evaluation of MHP, and final community presentation. On the basis of the observed and the felt needs of the community, we found the real needs and prioritized them as follows. For community: Proper water purification, information about common diseases, KAP on diseases, knowledge on TB and DOTS. For school-going children: Education on environmental sanitation, education on personal hygiene - teeth brushing and hand washing, adolescent health education. We launched micro health project (MHP) on these topics, conducting school-based as well as community-based programs. Journal of Gandaki Medical College Vol. 10, No. 1, 2017, Page: 59-62
Neuronavigation and 3D fluoroscopy–guided lag screw reduction and osteosynthesis for traumatic spondylolistheses of the axis: a path worth exploring?
Authors: Zeden Jan-Philip , Müller Jan-Uwe , Mohamed El Refaee Ehab Ahmed , Schroeder Henry W. S. , Pillich Dirk T.
Published: August 2017

OBJECTIVE

In traumatic spondylolistheses of the axis, there is a marked heterogeneity of the observed injury patterns, with a wide range of the severity—from stable fractures, which can be treated conservatively with very good success, to highly unstable fractures, which should be treated surgically. A number of classification systems have been devised to assess the instability of the injuries and to derive a corresponding therapy recommendation. In particular, the results and recommendations regarding medium-severity cases are still inconclusive. Minimally invasive percutaneous procedures performed using modern techniques such as 3D fluoroscopy and neuronavigation have the potential for improvements in the therapeutic outcome and procedural morbidity against open surgical procedures and conservative therapy.

METHODS

A minimally invasive method using 3D fluoroscopy and neuronavigation for percutaneous lag screw osteosynthesis of the pars interarticularis was performed in 12 patients with a Levine-Edwards Type II fracture. Ten patients had an isolated hangman’s fracture and 2 patients had an additional odontoid fracture of the axis (Type II according to the Anderson and D’Alonzo classification system). Complications, operating parameters, screw positions, and bony fusion were evaluated for the description and evaluation of the technique.

RESULTS

In 6 men and 6 women, percutaneous lag screw osteosynthesis was performed successfully. Correct placement could be verified postoperatively for all inserted screws. In the case series, nonunion was not observed. In all patients with a complete follow-up, a bony fusion, an intact vertebral alignment, and no deformity could be detected on CT scans obtained after 3 months.

CONCLUSIONS

The percutaneous pars interarticularis lag screw osteosynthesis is a minimally invasive and mobility-preserving surgical technique. Its advantages over alternative methods are its minimal invasiveness, a shortened treatment time, and high fusion rates. The benefits are offset by the risk of injury to the vertebral arteries. The lag screw osteosynthesis is only possible with Levine-Edwards Type II fractures, because the intervertebral joints to C-3 are functionally preserved. A further development and evaluation of the operative technique as well as comparison with conservative and alternative surgical treatment options are deemed necessary.
Explaining the orthography–phonology interface in written corpora: an Optimality–Theoretic approach
Authors: Yildiz Yasemin
Published: August 2017

This paper has two goals. The first goal is to contribute to the literature of Second Language Writing Systems (L2WS) by focussing on the British University in Dubai (BUiD) and the Arab Learner Corpus (BALC). The second is to demonstrate the close orthography–phonology interface in L2WS and critically address the issue of reform in a script. Unlike previous studies, which provide a holistic and descriptive analysis of all possible spelling errors of Arab learners of English (e.g., Haggan, 1991 ; and Randall and Groom, 2009 ), this study is different in two ways. First, BALC will be interpreted within a markedness framework and a constraint-based theory known as Optimality Theory. Second, particular emphasis will be given to the erroneous spelling forms which appear in lexical items exclusively with complex onset and coda clusters at the phonological level. The motive for this study is to look beyond spelling errors and bridge linguistic theory with learner corpora. The sub-corpora will be identified and categorised by using the Wmatrix3 program ( Rayson, 2003 , 2005 ). The fulfilment of the above goals will provide new insights for researchers and teachers who are working closely in the areas of L2WS and learner corpora.
Patterns of verbal agreement with collective nouns taking pluralof-dependents: a corpus-based analysis of syntactic distance
Authors: Fernández-Pena Yolanda
Published: August 2017

In this study, I investigate the patterns of verbal agreement of twenty-three singular collective nouns in English which take plural of-dependents (e.g., a group of children or a bunch of people). The main aim is to explore the extent to which this constituent may influence the number of the main verb, by considering factors such as the role of overt morphological markers for number in the oblique noun and the influence of syntactic distance on the patterns of verbal agreement. The data will show strong conditioning effects of the plural of-dependent on the verb, in triggering plural verbal number, for example. Contrary to what has been claimed hitherto, syntactic distance does not result in an increase of semantic (i.e., plural) agreement in this type of construction. In fact, the non-overtly marked plural noun people, whose influence on verbal agreement is strong in local syntactic domains, shows a considerable decrease in the proportion of plural verbal forms which it takes with increasing distance, contrary to overtly marked plural nouns. Finally, in light of the grammaticalisation suffered by homologous constructions such as a lot of, I will also consider the role of verbal agreement in the possible idiomatisation of the structures that I scrutinise here.
Colossal magnetoresistance manganites
Authors: Bebenin N G , Zainullina R I , Ustinov V V
Published: August 2017

We review lattice, thermodynamic, transport, high-frequency, and optical properties of Re1 − x

Dx
MnO3 manganites, where Re is a rare earth and D is usually an alkaline-earth element. Colossal magnetoresistance (CMR) is the most famous effect observed in manganites near the Curie temperature T
C. It is shown that the temperature and magnetic field dependences of the magnetocaloric effect, resistivity, magnetoresistance, Hall effect, and thermopower near T
C depend on whether the magnetic transition is of first or second order. The possibility of applying the well-known Banerjee criterion to inhomogeneous ferromagnets is discussed. Special attention is paid to various inhomogeneities characteristic of the manganites, including the coexistence of different crystallographic phases, metallic inclusions in the semiconductor matrix, and polarons.
Assessing the Ability of the DDES Turbulence Modeling Approach to Simulate the Wake of a Bluff Body
Authors: Boudreau Matthieu , Dumas Guy , Veilleux Jean-Christophe
Published: August 2017

A detailed numerical investigation of the flow behind a square cylinder at a Reynolds number of 21,400 is conducted to assess the ability of the delayed detached-eddy simulation (DDES) modeling approach to accurately predict the velocity recovery in the wake of a bluff body. Three-dimensional unsteady Reynolds-averaged Navier–Stokes (URANS) and DDES simulations making use of the Spalart–Allmaras turbulence model are carried out using the open-source computational fluid dynamics (CFD) toolbox OpenFOAM-2.1.x, and are compared with available experimental velocity measurements. It is found that the DDES simulation tends to overestimate the averaged streamwise velocity component, especially in the near wake, but a better agreement with the experimental data is observed further downstream of the body. The velocity fluctuations also match reasonably well with the experimental data. Moreover, it is found that the spanwise domain length has a significant impact on the flow, especially regarding the fluctuations of the drag coefficient. Nonetheless, for both the averaged and fluctuating velocity components, the DDES approach is shown to be superior to the URANS approach. Therefore, for engineering purposes, it is found that the DDES approach is a suitable choice to simulate and characterize the velocity recovery in a wake.
A Biomechanical Study for Developing Wearable-Sensor System to Prevent Hip Fractures among Seniors
Authors: Shan Gongbing , Zhang Xiang , Meng Mingliang , Wilde Brandie
Published: August 2017

As the population ages, falls are becoming a major health problem, not only for those with some degree of balance or mobility impairment, but also among healthy active seniors. Previous studies suggest that the degradation of human sensorimotor function related to age contributes to falls. Hip bones are among the most frequently fractured body parts resulting from falls. Hip fractures are a frequent cause of early death, functional dependence, and high medical care costs. The current prevention method is to use hip protectors. Unfortunately, it often fails to do so because the pocket containing the pad can move away from the area during falls. Additionally, some seniors refuse to use hip protectors because they find them constraining. Hence, a new protector that is only activated during a fall is much desired. The current study explored the possibility via biomechanical analyses for building a wearable sensor system that triggers a mini-airbag system during a fall, i.e., the air-pad is only present for protection when a fall occurs. The results have revealed that two sensors placed on the left and right shoulder would be best for a detection of any-direction fall and could be applied for building a wearable sensor system for prevention of hip fractures resulting from falls.
Monitoring of Land-Surface Deformation in the Karamay Oilfield, Xinjiang, China, Using SAR Interferometry
Authors: Aimaiti Yusupujiang , Yamazaki Fumio , Liu Wen , Kasimu Alimujiang
Published: August 2017

Synthetic Aperture Radar (SAR) interferometry is a technique that provides high-resolution measurements of the ground displacement associated with various geophysical processes. To investigate the land-surface deformation in Karamay, a typical oil-producing city in the Xinjiang Uyghur Autonomous Region, China, Advanced Land Observing Satellite (ALOS) Phased Array L-band Synthetic Aperture Radar (PALSAR) data were acquired for the period from 2007 to 2009, and a two-pass differential SAR interferometry (D-InSAR) process was applied. The experimental results showed that two sites in the north-eastern part of the city exhibit a clear indication of land deformation. For a further evaluation of the D-InSAR result, the Persistent Scatterer (PS) and Small Baseline Subset (SBAS)-InSAR techniques were applied for 21 time series Environmental Satellite (ENVISAT) C-band Advanced Synthetic Aperture Radar (ASAR) data from 2003 to 2010. The comparison between the D-InSAR and SBAS-InSAR measurements had better agreement than that from the PS-InSAR measurement. The maximum deformation rate attributed to subsurface water injection for the period from 2003 to 2010 was up to approximately 33 mm/year in the line of sight (LOS) direction. The interferometric phase change from November 2007 to June 2010 showed a clear deformation pattern, and the rebound center has been expanding in scale and increasing in quantity.
Electromagnetic Field Analysis of an Electric Dipole Antenna Based on a Surface Integral Equation in Multilayered Dissipative Media
Authors: Xu Yidong , Xue Wei , Li Yingsong , Guo Lili , Shang Wenjing
Published: August 2017

In this paper, a novel method based on the Poggio–Miller–Chang-Harrington–Wu–Tsai (PMCHWT) integral equation is presented to study the electromagnetic fields excited by vertical or horizontal electric dipoles in the presence of a layered region which consists of K-layered dissipative media and the air above. To transform the continuous integral equation into a block tridiagonal matrix with the feature of convenient solution, the Rao–Wilton–Glisson (RWG) functions are introduced as expansion and testing functions. The electromagnetic fields excited by an electric dipole are calculated and compared with the available results, where the electric dipole antenna is buried in the non-planar air–sea–seabed, air–rock–earth–mine, and multilayered sphere structures. The analysis and computations demonstrate that the method exhibits high accuracy and solving performance in the near field propagation region.
Remote Servo Tuning System for Multi-Axis CNC Machine Tools Using a Virtual Machine Tool Approach
Authors: Lin Chien-Yu , Lee Ching-Hung
Published: August 2017

Servo systems affect the performances of machining in accuracy and surface quality for high speed and precision machine tools. This study introduces an efficient servo tuning technique for Computer Numerical Control (CNC) feed drive systems using particle swarm optimization (PSO) algorithm by virtual machine tool approach. The proposed approach contained a system identification phase and a servo tuning phase based on the same bandwidth for all axes feed drive systems. The PSO algorithm was adopted to obtain the system parameters and maximize the corresponding bandwidth. An efficient two-step servo tuning method based on gain and phase margins was proposed for high speed and precision requirements. All feed drive systems controller gains were optimized simultaneously for synchronization. A remote system called Machine Dr. was established for servo tuning and monitoring. Simulation and experimental results were introduced to illustrate the effectiveness of the proposed approach.
Evaluation of the Common Land Model (CoLM) from the Perspective of Water and Energy Budget Simulation: Towards Inclusion in CMIP6
Authors: Li Chengwei , Lu Hui , Yang Kun , Wright Jonathon S. , Yu Le , Chen Yingying , Huang Xiaomeng , Xu Shiming
Published: August 2017

Land surface models (LSMs) are important tools for simulating energy, water and momentum transfer across the land–atmosphere interface. Many LSMs have been developed over the past 50 years, including the Common Land Model (CoLM), a LSM that has primarily been developed and maintained by Chinese researchers. CoLM has been adopted by several Chinese Earth System Models (GCMs) that will participate in the Coupled Model Intercomparison Project Phase 6 (CMIP6). In this study, we evaluate the performance of CoLM with respect to simulating the water and energy budgets. We compare simulations using the latest version of CoLM (CoLM2014), the previous version of CoLM (CoLM2005) that was used in the Beijing Normal University Earth System Model (BNU-GCM) for CMIP5, and the Community Land Model version 4.5 (CLM4.5) against global diagnostic data and observations. Our results demonstrate that CLM4.5 outperforms CoLM2005 and CoLM2014 in simulating runoff (R), although all three models overestimate runoff in northern Europe and underestimate runoff in North America and East Asia. Simulations of runoff and snow depth (SNDP) are substantially improved in CoLM2014 relative to CoLM2005, particularly in the Northern Hemisphere. The simulated global energy budget is also substantially improved in CoLM2014 relative to CoLM2005. Simulations of sensible heat (SH) based on CoLM2014 compare favorably to those based on CLM4.5, while root-mean-square errors (RMSEs) in net surface radiation indicate that CoLM2014 (RMSE = 16.02 W m−2) outperforms both CoLM2005 (17.41 W m−2) and CLM4.5 (23.73 W m−2). Comparisons at regional scales show that all three models perform poorly in the Amazon region but perform relatively well over the central United States, Siberia and the Tibetan Plateau. Overall, CoLM2014 is improved relative to CoLM2005, and is comparable to CLM4.5 with respect to many aspects of the energy and water budgets. Our evaluation confirms CoLM2014 is suitable for inclusion in Chinese GCMs, which will increase the diversity of LSMs considered during CMIP6.
Organic vs. Conventional Milk: Some Considerations on Fat-Soluble Vitamins and Iodine Content
Authors: Manzi Pamela , Durazzo Alessandra
Published: August 2017

The organic food market is considerably expanding all over the world, and the related dairy market represents its third most important sector. The reason lies in the fact that consumers tend to associate organic dairy products with positive perceptions: organic milk is eco- and animal-friendly, is not produced with antibiotics or hormones, and according to general opinion, provides additional nutrients and beneficial properties. These factors justify its higher cost. These are the reasons that explain extensive research into the comparison of the differences in the amount of chemical compounds between organic and conventional milk. However, it is not simple to ascertain the potential advantage of organic food from the nutritional point of view, because this aspect should be determined within the context of the total diet. Thus, considering all the factors described above, the purpose of this work is to compare the amount of selected nutrients (i.e., iodine and the fat-soluble vitamins such as alfa-tocopherol and beta-carotene) in organic and conventional milk, expressed as the percentage of recommended daily intakes in one serving. In detail, in order to establish the real share of these biologically active compounds to the total diet, their percent contribution was calculated using the Dietary Reference Values for adults (both men and women) adopted by the European Food Safety Authority. According to these preliminary considerations, the higher cost of organic milk can mainly be explained by the high costs of the management of specific farms and no remarkable or substantial benefits in human health can be ascribed to the consumption of organic milk. In this respect, this paper wants to make a small contribution to the estimation of the potential value and nutritional health benefits of organic food, even though further studies are needed.
Positive and Negative Affect More Concurrent among Blacks than Whites
Authors: Lankarani Maryam , Assari Shervin
Published: August 2017

Background: While positive and negative affect are inversely linked, people may experience and report both positive and negative emotions simultaneously. However, it is unknown if race alters the magnitude of the association between positive and negative affect. The current study compared Black and White Americans for the association between positive and negative affect. Methods: We used data from MIDUS (Midlife in the United States), a national study of Americans with an age range of 25 to 75. A total number of 7108 individuals were followed for 10 years from 1995 to 2004. Positive and negative affect was measured at baseline (1995) and follow-up (2004). Demographic (age and gender), socioeconomic (education and income) as well as health (self-rated health, chronic medical conditions, and body mass index) factors measured at baseline were covariates. A series of linear regressions were used to test the moderating effect of race on the reciprocal association between positive and negative affect at baseline and over time, net of covariates. Results: In the pooled sample, positive and negative affect showed inverse correlation at baseline and over time, net of covariates. Blacks and Whites differed in the magnitude of the association between positive and negative affect, with weaker inverse associations among Blacks compared to Whites, beyond all covariates. Conclusion: Weaker reciprocal association between positive and negative affect in Blacks compared to Whites has implications for cross-racial measurement of affect and mood, including depression. Depression screening programs should be aware that race alters the concordance between positive and negative affect domains and that Blacks endorse higher levels of positive affect compared to Whites in the presence of high negative affect.
Incorporation of Large Impurity Atoms into the Diamond Crystal Lattice: EPR of Split-Vacancy Defects in Diamond
Authors: Nadolinny Vladimir , Komarovskikh Andrey , Palyanov Yuri
Published: August 2017

Diamond is a unique mineral widely used in diverse fields due to its remarkable properties. The development of synthesis technology made it possible to create diamond-based semiconductor devices. In addition, doped diamond can be used as single photon emitters in various luminescence applications. Different properties are the result of the presence of impurities or intrinsic defects in diamond. Thus, the investigation of the defect formation process is of particular interest. Although hydrogen, nitrogen, and boron have been known to form different point defects, the possibility for large impurity atoms to incorporate into the diamond crystal structure has been questioned for a long time. In the current paper, the paramagnetic nickel split-vacancy defect in diamond is described, and the further investigation of nickel-, cobalt-, titanium-, phosphorus-, silicon-, and germanium-related defects is discussed.
The Internal Structure of Yellow Cuboid Diamonds from Alluvial Placers of the Northeastern Siberian Platform
Authors: Ragozin Alexey , Zedgenizov Dmitry , Kuper Konstantin , Kalinina Viktoria , Zemnukhov Alexey
Published: August 2017

Yellow cuboid diamonds are commonly found in diamondiferous alluvial placers of the Northeastern Siberian platform. The internal structure of these diamonds have been studied by optical microscopy, X-Ray topography (XRT) and electron backscatter diffraction (EBSD) techniques. Most of these crystals have typical resorption features and do not preserve primary growth morphology. The resorption leads to an evolution from an originally cubic shape to a rounded tetrahexahedroid. Specific fibrous or columnar internal structure of yellow cuboid diamonds has been revealed. Most of them are strongly deformed. Misorientations of the crystal lattice, found in the samples, may be caused by strains from their fibrous growth or/and post-growth plastic deformation.
Effect of Nitrogen Impurities on the Raman Line Width in Diamond, Revisited
Authors: Surovtsev Nikolay V. , Kupriyanov Igor N.
Published: August 2017

The results of a high-resolution Raman scattering study of a diamond crystal with a high content of single substitutional nitrogen impurities (550 ppm) in the temperature range from 50 to 673 K are presented and compared with the data for defect-free diamond. It is established that the increase of the nitrogen concentration in diamond leads to the temperature-independent increase of the Raman line width. Analysis of the experimental data allows us to conclude that this broadening should be attributed to the defect-induced shortening of the Raman phonon lifetime. We believe that this mechanism is responsible for the increase of the Raman line width caused by most point-like defects in diamond. No pronounced effects of the nitrogen defects on the Raman line position and phonon anharmonicity are observed.
Overview of German Additive Manufacturing Companies
Authors: Baumann Felix , Roller Dieter
Published: August 2017

This dataset is the description of a curated list of companies involved in additive manufacturing in Germany. The companies included are of various categories, such as 3D printing providers, hardware manufacturers, software developers and vendors. The list was compiled through literature and Internet-based research, resulting in the compilation of information from a number of resources, such as the Bundesanzeiger (Federal Gazette), the Registergerichte (Register Courts), the respective websites themselves and a B2B marketplace (Wer liefert Was?). The aim of compiling this list is to provide information to researchers on the current situation of 3D printing in Germany.
Optimization of Active Current for Large-Scale Wind Turbines Integrated into Weak Grids for Power System Transient Stability Improvement
Authors: Zhang Dongliang , Yuan Xiaoming
Published: August 2017

Power system transient stability is a challenge when integrating large-scale wind turbines into weak grids. This paper addresses the issue of transient stability in such situations by optimizing a wind turbine’s active current behavior. A wind turbine’s active current reference controller and its setting optimization method are proposed based on analyses of two associated problems: the mechanism for improving transient stability of a single (synchronous) machine infinite bus (SMIB) system, as well as the various physical factor dependencies dictating how active and reactive wind turbine currents affect the swing dynamics of synchronous machines. Analysis of the first problem guided the design of the controller’s main structure. Analysis of the second problem guided selection of the control object within a wind turbine’s active and reactive currents, as well as helped recognition of the influential physical factors that must be considered in the parameter setting process. The efficiency of the controller and the validity of the analyses were verified by case studies using Kundur’s two-area system.
Study of a High-Pressure External Gear Pump with a Computational Fluid Dynamic Modeling Approach
Authors: Frosina Emma , Senatore Adolfo , Rigosi Manuel
Published: August 2017

A study on the internal fluid dynamic of a high-pressure external gear pump is described in this paper. The pump has been analyzed with both numerical and experimental techniques. Starting from a geometry of the pump, a three-dimensional computational fluid dynamics (CFD) model has been built up using the commercial code PumpLinx®. All leakages have been taken into account in order to estimate the volumetric efficiency of the pump. Then the pump has been tested on a test bench of Casappa S.p.A. Model results like the volumetric efficiency, absorbed torque, and outlet pressure ripple have been compared with the experimental data. The model has demonstrated the ability to predict with good accuracy the performance of the real pump. The CFD model has been also used to evaluate the effect on the pump performance of clearances in the meshing area. With the validated model the pressure inside the chambers of both driving and driven gears have been studied underlining cavitation in meshing fluid volume of the pump. For this reason, the model has been implemented in order to predict the cavitation phenomena. The analysis has allowed the detection of cavitating areas, especially at high rotation speeds and delivery pressure. Isosurfaces of the fluid volume have been colored as a function of the total gas fraction to underline where the cavitation occurs.
Reconstructed Inter-Annual Variation in September–October Precipitation for the Upper Reaches of the Heihe River and Its Implications for Regional Drought Conditions
Authors: Wang Bo , Chen Tuo , Xu Guobao , Wu Guoju
Published: August 2017

Due to the lack of available long-term climatic records, data related to past autumn precipitation variability throughout Northwest China, especially high-frequency variation, remains limited. In this study, it was found that inter-annual changes in Qinghai spruce radial growth were significantly and negatively (p < 0.05) correlated to inter-annual differences in precipitation during the late growing season (September–October) at all sampling sites in the upper reaches of the Heihe River. Based on the growth–climate relationship, a reconstruction of the inter-annual variation in September–October precipitation from 1839 was developed. With the help of this reconstruction, we successfully captured increased inter-annual variations in September–October precipitation during 1855–1861, 1892–1902, and 1969–1986. Furthermore, we found that increased precipitation variation might be related to variation in the westerlies and instability in the relationship between the regional westerly and precipitation. Moreover, our reconstructed data significantly correlated to the drought index (i.e., October SPEI_01) and moisture-related parameters (i.e., September–October cloud fraction), suggesting that our reconstructed data could be used as an indicator of the drought condition in the Heihe River Basin during the late growing season.
Integration of Fire Risk in a Sustainable Forest Management Model
Authors: Costa Freitas Maria , Xavier António , Fragoso Rui
Published: August 2017

In Mediterranean areas, forest fires are a considerable risk most years. The seasonality of the climate with a dry summer, high temperatures and low rainfall (which implies increased flammability of materials) is one of the main factors in the ignition and progression of fires. This factor conjugated with more favourable biophysical conditions (e.g., high slopes, aspect) leads to easy propagation and the increasingly destructive power of such phenomena. To prevent and reduce the consequences of forest fires, it is necessary to simulate and forecast the territory use and management, not only focused on forest areas, but also on all land uses and agricultural activities that may coexist there, considering the probability of fire occurrence. The objective of this paper is to present a methodological approach to address the integration of fire risk in integrated Mediterranean forest management models. The methodological approach considers simultaneously the climatic conditions through different times of the year (more or less favourable to forest fire damage) and structural conditions addressed to land uses, aspect, slope, roads and demographic density. The methodological approach was implemented in a management area located in the Algarve, in southern Portugal. The results for the Algarve region showed that the proposed approach is very useful for managers, since it allowed the calculation of fire susceptibility, vulnerability and fire damage, according to several climatic scenarios. It also allowed the incorporation of different paths regarding different fire risk conditions and the minimization of risk due to fire damage through different management responses.
Remnant Trees in Enrichment Planted Gaps in Quintana Roo, Mexico: Reasons for Retention and Effects on Seedlings
Authors: Navarro-Martínez Angélica , Palmas Sebastian , Ellis Edward , Blanco-Reyes Pascual , Vargas-Godínez Carolina , Iuit-Jiménez Ana , Hernández-Gómez Irving , Ellis Peter , Álvarez-Ugalde Alfredo , Carrera-Quirino Yavé , Armenta-Montero Samaria , Putz Francis
Published: August 2017

Natural forest management in the tropics is often impeded by scarcity of advanced regeneration of commercial species. To supplement natural regeneration in a forest managed by a community in the Selva Maya of Mexico, nursery-grown Swietenia macrophylla seedlings were planted in multiple-tree felling gaps, known as bosquetes. Remnant trees are often left standing in gaps for cultural and economic reasons or due to their official protected status. We focus on these purposefully retained trees and their impacts on planted seedlings. Sampled bosquetes were 400–1800 m2, of which remnant trees covered a mean of 29%. Seedling height growth rates over the first 18 months after out-planting more than doubled with increased canopy openness from 0.09 m year−1 under medium cover to 0.22 m year−1 in full sun. Liana infestations and shoot tip damage were most frequent on seedlings in the open, but, contrary to our expectations, height growth rates were 0.14 m year−1 faster for liana-infested seedlings than non-infested and did not differ between damaged and undamaged seedlings. Apparently the more rapid height growth of well-illuminated seedlings more than compensated for the effects of lianas or shoot tip damage. Despite the abundance of remnant trees and their negative effects on seedling growth, enrichment planting in bosquetes has potential for community-based natural forest management in the tropics in supplementing natural regeneration of commercial species. One obvious recommendation is to leave fewer remnant trees, especially those of commercial species that are non-merchantable due to stem defects and trees retained for no apparent reason, which together constituted half of the remnant crown cover in the sampled bosquetes. Finally, given the rapid growth of lianas and understory palms in large canopy gaps, at least the most vigorous of the planted seedlings should be tended for at least two years.
Recent Patterns in Climate, Vegetation, and Forest Water Use in California Montane Watersheds
Authors: Saksa Philip , Safeeq Mohammad , Dymond Salli
Published: August 2017

California has recently experienced one of the worst droughts on record, negatively impacting forest ecosystems across the state. As a major source of the region’s water supply, it is important to evaluate the vegetation and water balance response of these montane forested watersheds to climate variability across the range of rain- to snow-dominated precipitation regimes. The Standardized Precipitation Index (SPI) and the Standardized Runoff Index (SRI) were used to capture the hydrologic drought signal, and MODIS vegetation indices (i.e., the normalized difference vegetation index and the enhanced vegetation index) were used to evaluate the vegetation and evapotranspiration response in three headwater catchments. The study catchments comprised a low elevation rain-dominated site (Caspar Creek) on the northern California coast, a mid-elevation site with a mix of rain and snow (Providence Creek) in the California Sierra Nevada, and a high elevation snow-dominated site (Bull Creek) in the Sierra Nevada. Lowest SPI values occurred in the third drought year of 2014 for all sites. Lowest SRI was in 2014 for Caspar, but in 2015 for Providence and Bull, reflecting differences in snowpack-delayed runoff and subsurface storage capacity between the lower and higher elevation watersheds. The most accurate water balance closure using evapotranspiration estimates from vegetation indices was within 10% of measured precipitation at snow-dominated Bull. The rain-dominated Caspar watershed had the highest vegetation index values and annual evapotranspiration, with the lowest variability over the previous 13 years (2004–2016). Vegetation index values and annual evapotranspiration decreased with increasing elevation and snow contribution to precipitation. Both snow-influenced Sierra Nevada watersheds showed elevated vegetation and evapotranspiration responses to interannual climate variability. There remains a need for institutional support to expand long-term observations in remote forested mountain watersheds to monitor and research these changing and extreme environmental conditions in source watershed regions.
Seasonal Variation in Fat Quality and Conjugated Linoleic Acid Content of Dairy Products from the Tropics: Evidence of Potential Impact on Human Health
Authors: Nunes Juliana , Silva Monalisa , Perrone Daniel , Torres Alexandre
Published: August 2017

Seasonal variation in conjugated linoleic acid (CLA) content and atherogenicity index (AI) of retail dairy products (whole milk, butter, and prato, a soft yellow cheese) from Brazil was investigated. CLA content of dairy products ranged from 0.55 to 1.53 g CLA/100 g fatty acids and was on average 25% higher during the rainy season compared to the dry season. Dairy products from the rainy season also had lower AI levels, indicating a lower risk of causing cardiovascular disease in consumers. This seasonality led to estimated seasonal variations of milk fat quality consumed by the population of southeastern Brazil, meaning 15% and 19% variation in daily intake of CLA and AI values, respectively. Dietary consumption of CLA (g/day) was greater in the rainy season, despite higher intake of dairy products during the dry season. We show that dairy products produced during the rainy season in Brazil are expected to be more beneficial to human health than are those produced during the dry season.
Characterization and Expression Profiling of Camellia sinensis Cinnamate 4-hydroxylase Genes in Phenylpropanoid Pathways
Authors: Xia Jinxin , Liu Yajun , Yao Shengbo , Li Ming , Zhu Mengqing , Huang Keyi , Gao Liping , Xia Tao
Published: August 2017

Cinnamate 4-hydroxylase (C4H), a cytochrome P450-dependent monooxygenase, participates in the synthesis of numerous polyphenoid compounds, such as flavonoids and lignins. However, the C4H gene number and function in tea plants are not clear. We screened all available transcriptome and genome databases of tea plants and three C4H genes were identified and named CsC4Ha, CsC4Hb, and CsC4Hc, respectively. Both CsC4Ha and CsC4Hb have 1518-bp open reading frames that encode 505-amino acid proteins. CsC4Hc has a 1635-bp open reading frame that encodes a 544-amino acid protein. Enzymatic analysis of recombinant proteins expressed in yeast showed that the three enzymes catalyzed the formation of p-coumaric acid (4-hydroxy trans-cinnamic acid) from trans-cinnamic acid. Quantitative real-time PCR (qRT-PCR) analysis showed that CsC4Ha was highly expressed in the 4th leaf, CsC4Hb was highly expressed in tender leaves, while CsC4Hc was highly expressed in the young stems. The three CsC4Hs were induced with varying degrees by abiotic stress treatments. These results suggest they may have different subcellular localization and different physiological functions.
Quantum Notes on Classic Places
Authors: Segatto Diego
Published: August 2017

I would like to sing about an unstable, yet constant force that stresses and pushes imagination. It makes cultural and social transformations a process to experience in person. [...]
Challenges in Expanding Access to Dialysis in South Africa—Expensive Modalities, Cost Constraints and Human Rights
Authors: Etheredge Harriet , Fabian June
Published: August 2017

South Africa is a country with two distinct health sectors, which are both characterised by inequalities. Within this context, patients with end stage renal disease face unique and sometimes impenetrable barriers to accessing dialysis. There are a number of reasons for this situation. These include: the South African government’s endorsement of discordant, unequal policies, which disadvantage the most vulnerable; a lack of robust national guidelines; and divisive rationing practices, which are ad hoc and place the burden of responsibility for rationing dialysis on the clinician. In this paper, we trace the socio-economic mechanisms of how we have come to be in this situation, and overlay this with a detailed examination of South African legislation. Finally, we make comprehensive practical recommendations for rectifying the situation, which include engagement with key stakeholders, public–private partnerships, and more equitable funding mechanisms.
Chronic Respiratory Disorders and Their Treatment among Older People with Intellectual Disability and/or Autism Spectrum Disorder in Comparison with the General Population
Authors: Axmon Anna , Höglund Peter , Ahlström Gerd
Published: August 2017

Respiratory disorders are common among people with intellectual disabilities (ID). However, few studies have investigated these disorders among older people with ID. We identified 7936 people, aged 55+ years, with ID and a reference cohort from the general population. Data on diagnoses of chronic respiratory disorders, with a focus on asthma and chronic obstructive pulmonary disease (COPD), were collected, as was information on health care visits due to such disorders. We also added data on the prescription of drugs for obstructive airway diseases. Whereas the risk of having at least one diagnosis of asthma during the study period was similar in the two cohorts, people with ID were less likely than the general population to have been diagnosed with COPD. The same was found for health care visits due to asthma and COPD, respectively. The patterns of drug prescription were similar among people with ID and the general population, with the exception of adrenergics for systemic use, which were more commonly prescribed to people with ID. Thus, older people with ID do not seem to have an increased risk of asthma or COPD. Moreover, the indications are that when diagnosed with any of these disorders, they receive treatment adapted to their particular needs.
Exogenous GR24 Alleviates Cadmium Toxicity by Reducing Cadmium Uptake in Switchgrass (Panicum virgatum) Seedlings
Authors: Tai Zhenglan , Yin Xinqiang , Fang Zhigang , Shi Gaoling , Lou Laiqing , Cai Qingsheng
Published: August 2017

Strigolactones (SLs) are classified into plant hormones, playing a key role as a mediator of plant growth in response to several abiotic stresses, including drought and salinity. However, the role of SLs in cadmium (Cd)-induced stress to plants is still unknown. The physiological responses of switchgrass (Panicum virgatum) stressed in 10 μmol L-1 Cd to exogenous synthetic SLs analog, GR24 were studied in hydroponics. The Cd stress significantly caused the adverse effects on plant growth and root morphology, inhibited photosynthesis, but boosted lipid peroxidation of Switchgrass seedlings. After treatment of 1 μmol L-1 GR24, the above adverse effects caused by Cd stress were significantly alleviated, mainly reflects in improvement of shoot biomass, relative water content, root development, chlorophyll contents, activities of typical antioxidant enzymes, nutrient uptake. The reason for exogenous GR24 alleviating cadmium toxicity might be owing to that exogenous GR24 promoted the content of endogenous SLs, increased some essential element Fe (iron), Zn (zinc), Mn (manganese) and Cu (copper) uptake and reduced cadmium uptake, accumulation and partition in shoot of switchgrass seedlings.