bluuebunny/crossref_metadata_2025 huggingface dataset:
Long‐Term Effect of Four Surgical Periodontal Therapies and One Non‐Surgical Therapy: A Systematic Review and Meta‐Analysis
Authors: Mailoa James , Lin Guo‐Hao , Khoshkam Vahid , MacEachern Mark , Chan Hsun‐Liang , Wang Hom‐Lay
Published: June 2015

Background: The aim of this systematic review is to evaluate the long term (≥2 years) effect of four surgical and non‐surgical therapies in treating periodontal disease.

Methods: An electronic search of four databases and a hand search of peer‐reviewed journals for relevant articles were conducted. Prospective human controlled clinical trials were included that compared surgical therapy to non‐surgical therapy in ≥10 patients diagnosed with chronic periodontitis with a follow‐up period of ≥2 years and that reported change in probing depth (PD) and clinical attachment level (CAL) after the therapy. Random effect meta‐analysis was performed to compare the outcome of surgical and non‐surgical therapy in shallow, moderate, and deep PD.

Results: Eight human prospective clinical trials were included. In 1‐ to 3‐mm PD, scaling and root planing (SRP), modified Widman flap (MWF), and osseous surgery (OS) resulted in 23.2%, 39.4%, and 61.39% CAL loss, respectively; SRP, MWF, and OS resulted in increased mean PD of 2.5%, 3.3%, and 6.3%, respectively. In 4‐ to 6‐mm PD, SRP, MWF, and OS resulted in 8.4%, 6.5%, and 5.22% CAL gain, respectively; SRP, MWF, and OS resulted in 18.7%, 25.4%, and 30.8% PD reduction, respectively. In PD ≥7 mm, SRP, MWF, and OS resulted in 9.8%, 14.2%, and 9.38% CAL gain, respectively; SRP, MWF, and OS resulted in mean PD reduction of 21.6%, 33.1%, and 42.8%, respectively.

Conclusions: Surgical therapy had significantly more CAL loss than non‐surgical therapy in shallow PD. In moderate PD, MWF had significantly more PD reduction than SRP, and there was significantly less CAL gain with surgical therapy. In deep PD, OS had significantly higher PD reduction than SRP.
Deja vu for Petroleum Engineers: A Cautionary Tale
Authors: Fernandez Tony
Published: June 2015

What’s Ahead–From TWA’s Editor-in-Chief

I remember my first year in the industry very fondly: it was 2006, oil prices had been climbing steadily for over half a decade, and the “big crew change” was starting to become dinner table discussion. The brain drain that would eventually come from the retirement of senior employees was imminent, experts advised, and it seemed like companies were taking advantage of the good times to hire like crazy as they positioned themselves to hedge the effect on their operations.

I vividly remember a recruitment event organized by a large independent during the ATCE for which they rented the entire Sea World theme park in San Antonio and threw a party for us. It was an extraordinarily memorable event for any impressionable recent grad, and the future seemed prosperous. The Petroleum Economist encapsulated the hiring spree by quoting the head of US recruiting for one of the supermajors as saying, “Times are very good for us…and we are expanding– USD 60 [a barrel] oil will do a lot for your business. At the same time…a large number of employees are in their 50s and we need to increase our hiring across the board.”

Academia listened to industry’s pleas for help, experiencing a meteoric rise in petroleum engineering enrollment not seen since the 1980s (Fig 1). Unfortunately, those students in the 1980s largely found themselves unemployed upon graduation as a result of cost-cutting measures following the oil price collapse of 1987, the result of which became the very same “lost generation” of talent that evidently now needs to be bridged by the big crew change.

Fast-forward to today and, after some wild swings in commodity prices, to be sure, we nonetheless see oil once again hovering at around the same USD 60 mark which I fondly recall from the birth of my career. But a quick study of the headlines paints a starkly different picture this time around, as seemingly every company is either laying off people, freezing hiring, or doing both. An onslaught of such headlines has turned the mood in university campuses to an anxious and somber (if not pessimistic) one, which is completely opposite to the confident euphoria when I was there. I encourage you to read the TWAInterAct section, which features comments from SPE student chapter presidents on how the price drop is affecting students.
How Petroleum Industry Young Professionals Can Survive the Oil Price Volatility
Authors: Okoroafor Rita , Munisteri Islin , Sturgess David , Zafar Asif
Published: June 2015

Soft Skills

Never mistake a lack of volatility for stability. Due to many influencing factors, the oil and gas industry has experienced several cycles of meteoric rises and plunges in oil price. With the volatility of oil prices comes key business decisions in the industry, which may or may not directly affect the career of young professionals (YPs). Fig. 1 shows the monthly crude oil prices from 1946 to November 2014, adjusted for inflation. Following significant oil price peaks, for example, in 1979 and 2008, were the declines. Below are some of the historically consistent reactions during downturns in oil prices:

An increased drive to develop alternative (and cheaper) sources of energy

Increased employment in industries other than the oil and gas industry*

Enrollment in petroleum engineering education decreased, but after staying steady for a few more years near the peak

Job cuts in organizations directly or indirectly related to the oil and gas industry

Job restructuring, such as giving international staff new roles in their home countries, within the oil and gas industry

Knowing that oil price is cyclic in nature and very volatile, how can one apply the past lessons today?

Be a High Performer

It is true that at USD 30/bbl no job is indispensable. Nonetheless, being a high performer improves your chances of surviving the volatile times while actively advancing your career. High performers are characterized by their ability to deliver consistent and excellent results with a reputation for being competent and trustworthy. They master technical challenges, continually refine their leadership skills, and act as role models with a positive attitude that enthuses the company culture.
Nodal Analysis for Unconventional Reservoirs—Principles and Application
Authors: Zhou Wentao , Banerjee Raj , Proano Eduardo
Published: June 2015

Nodal analysis is the standard technique used to evaluate the performance of integrated production systems. Two curves represent the capacities of the inflow and of the outflow, and the intersection of the two curves gives the solution operating point. Limitations of traditional nodal analysis include:

Results are offered only at a snapshot, not as a function of time. Inflow-performance-relationship (IPR) models are limited, with none available for shale gas wells. Analysis is performed on a well-by-well basis, with no account of multiwell interference.

We propose a new nodal-analysis method that enables the study of transient production systems, such as unconventional reservoirs, with IPR models generated from a high-speed semianalytical reservoir simulator and outflow curves generated from a steady-state pipeline simulator. The use of analytical reservoir simulation allows accurate, reliable modeling of the real inflow system. The new approach studies the time-lapse behavior of the system, with consideration of production history and neighboring-well interference.

This new method enables the study of transient deliverability at the wellhead, where the measurement is usually available, and shows the time-lapse relationship between wellhead pressure and production rate. We provide examples of wellhead deliverability and choke management and explain advantages of the method with case studies involving tight and shale wells. The method is also applied to design and optimize artificial lift in unconventional wells and to study the method's validity over time. In addition, we discuss an example of operational well dynamics with time-lapse nodal analysis.

Furthermore, this new method generates discussion about some concepts that are often taken for granted—What should be the definition of IPR in a transient production system? On the IPR curve, is the zero-rate-pressure the reservoir pressure? Can IPR curves at two different timesteps cross each other? Finding the answers to these questions will help us better understand production systems.

The commonly used productivity-index (PI) method is reviewed and compared with the new method. Results show that one should not use the PI method when well operational conditions change.
A meta-modeling framework for a specific social domain: Public opinion event
Authors: Fan Zongchen , Qiu Xiaogang , Dai Weihui , Ge Yuanzheng , Liu Liang , Duan Yunsuo
Published: June 2015

Due to the extensive social influence in modern information communication
environment, public opinion event has caused significant attention in
emergency management by the government. The formation and evolution of
public opinion event is a dynamically interactive process affected by the
participant?s complicated psychology and behaviors. Agent-based modeling
method can provide an effective and powerful tool to investigate the
emerging phenomena in a social simulation system. Although many
methodologies have been presented to support the standardized modeling, but
the transition from expertise or theory model to computing simulation model
is still a hard work for the sociologist, who usually lack of the required
technological skills. In order to step over this barrier, we propose a
domain-expert oriented methodology to guide the modeling process in a
specific social domain, and design a meta-modeling framework based on the
paradigm of Agent-Event-Environment (AEE) which can be considered as a basis
of developing a visual modeling environment or tools. By the application in
the real case of a major public opinion event, the proposed method has been
verified effectively and efficiently. Research work of this article provides
a valuable framework and methodology to deal with the transition of
expertise or theoretical knowledge into computing simulation for a specific
social domain.
Multimedia congestion control in wireless sensor networks
Authors: Bok Kyoungsoo , Ryu Eunkyung , Park Junho , Jung Jaijin , Yoo Jaesoo
Published: June 2015

In this paper, we propose a new congestion control scheme to minimize data
loss and maintain data quality in wireless multimedia sensor networks. The
proposed scheme extracts and transfers dynamic regions by considering
monitoring characteristics over multimedia sensor network environments to
reduce the transferred data. Furthermore, it can reduce the packet size by
deleting and transferring low-priority bit data by considering multimedia
data characteristics during congestion situations to minimize packet loss.
To show the superiority of the proposed scheme, we compare it with the
existing congestion control schemes through simulation.
A connectivity monitoring model of opportunistic sensor network based on evolving graph
Authors: Shu Jian , Jiang Shandong , Liu Qun , Liu Linlan , Geng Xiaotian
Published: June 2015

Connectivity is one of the most important parameters in network monitoring.
The connectivity model of Opportunistic Sensor Networks (OSN) can hardly be
established by traditional graph models due to the fact that its
connectivity is timing correlative and evolutionary, which makes it
extremely difficult to monitor an OSN. In order to solve the monitoring
problem, this paper builds an evolving graph model based on the theory of
evolving graph as a description of an OSN. It defines a series of parameters
to measure the connectivity of the OSN and establishes an monitoring model.
Meanwhile, this paper gives the key algorithms in building the model, the
Evolving-Graph-Modeling (EGM) algorithm and the Connected-Journey (CJ)
algorithm. The rationality of the monitoring model has been proven by a
prototype system and the simulation results. Extensive simulation results
show that the proposed connectivity monitoring model can indicate real
circumstances of OSN? connectivity, and it is applicable to monitoring an
opportunistic sensor network.
On the security enhancement of integrated electronic patient records information systems
Authors: Khan Muhammad , Chaturvedi Ankita , Mishra Dheerendra , Kumari Saru
Published: June 2015

Electronic patient records (EPR) information systems maintain the patients?
medical information on the web servers, and remain available to the medical
institutions, practitioners, and the academia. The transmission of data is
being done over the public network, which increases the privacy and security
risk. However, authentication mechanism tries to ensure secure and
authorized communication over insecure public network. In recent years,
several authentication protocols have been proposed, but most of them fail
to satisfy desirable security attributes. In this paper, we discuss the
failure of two authentication protocols for EPR information systems. To
overcome the flows, we present improved scheme for the integrated EPR
information systems. The correctness of proposed protocol is proved using
BAN logic. Moreover, the protocol performs is comparable and security is
efficient than the existing schemes.
A image segmentation algorithm based on differential evolution particle swarm optimization fuzzy c-means clustering
Authors: Liu Jiansheng , Qiao Shangping
Published: June 2015

This paper presents a hybrid differential evolution, particle swarm
optimization and fuzzy c-means clustering algorithm called DEPSO-FCM for
image segmentation. By the use of the differential evolution (DE) algorithm
and particle swarm optimization to solve the FCM image segmentation
influenced by the initial cluster centers and easily into a local optimum.
Empirical results show that the proposed DEPSO-FCM has strong anti-noise
ability; it can improve FCM and get better image segmentation results. In
particular, for the HSI color image segmentation, the DEPSO-FCM can
effectively solve the instability of FCM and the error split because of the
singularity of the H component.
In vitro and in vivo biofilm adhesion to esthetic coated arch wires and its correlation with surface roughness
Authors: Taha Mahasen , El-Fallal Abeer , Degla Heba
Published: June 2015

Objective: 

To evaluate the in vitro ability of esthetic coated rectangular arch wires to retain oral biofilms and in vivo biofilm formation on these wires after 4 and 8 weeks of clinical use and to correlate the findings with the surface roughness of these wires.

Materials and Methods: 

Three brands of esthetic coated nickel-titanium (NiTi) arch wires were selected. Arch wires retrieved after 4 and 8 weeks of intraoral use were obtained from 30 orthodontic patients. Surface roughness (SR) was assessed with an atomic force microscope. In vitro adhesion assays were performed using Streptococcus mutans (MS), Staphylococcus aureus, and Candida albicans. The amount of bacterial adhesion was quantified using the colony-count method. Paired t-test, analysis of variance, post hoc Tukey's test, and Pearson's correlation coefficient test were used for statistical analysis at the .05 level of significance.

Results: 

In vitro bacterial adhesion showed significant differences between wires in terms of MS adhesion (P  =  .01). All wires showed significant increases in SR (P  =  .001 after 4 weeks and .007 after 8 weeks) and biofilm adhesion (P  =  .0001 after 4 weeks and .045 after 8 weeks) after intraoral exposure. A significant positive correlation (P  =  .001 after 4 weeks and .05 after 8 weeks) was observed between these two variables in vivo, but the correlation was not significant for in vitro bacterial adhesion.

Conclusions: 

SR and biofilm adhesion increased after intraoral use at all time intervals. There was a positive correlation between SR and biofilm adhesion in vivo only.
Removal of Abnormal Myofilament O-GlcNAcylation Restores Ca2+ Sensitivity in Diabetic Cardiac Muscle
Authors: Ramirez-Correa Genaro A. , Ma Junfeng , Slawson Chad , Zeidan Quira , Lugo-Fagundo Nahyr S. , Xu Mingguo , Shen Xiaoxu , Gao Wei Dong , Caceres Viviane , Chakir Khalid , DeVine Lauren , Cole Robert N. , Marchionni Luigi , Paolocci Nazareno , Hart Gerald W. , Murphy Anne M.
Published: June 2015

Contractile dysfunction and increased deposition of O-linked β-N-acetyl-d-glucosamine (O-GlcNAc) in cardiac proteins are a hallmark of the diabetic heart. However, whether and how this posttranslational alteration contributes to lower cardiac function remains unclear. Using a refined β-elimination/Michael addition with tandem mass tags (TMT)–labeling proteomic technique, we show that CpOGA, a bacterial analog of O-GlcNAcase (OGA) that cleaves O-GlcNAc in vivo, removes site-specific O-GlcNAcylation from myofilaments, restoring Ca2+ sensitivity in streptozotocin (STZ) diabetic cardiac muscles. We report that in control rat hearts, O-GlcNAc and O-GlcNAc transferase (OGT) are mainly localized at the Z-line, whereas OGA is at the A-band. Conversely, in diabetic hearts O-GlcNAc levels are increased and OGT and OGA delocalized. Consistent changes were found in human diabetic hearts. STZ diabetic hearts display increased physical interactions of OGA with α-actin, tropomyosin, and myosin light chain 1, along with reduced OGT and increased OGA activities. Our study is the first to reveal that specific removal of O-GlcNAcylation restores myofilament response to Ca2+ in diabetic hearts and that altered O-GlcNAcylation is due to the subcellular redistribution of OGT and OGA rather than to changes in their overall activities. Thus, preventing sarcomeric OGT and OGA displacement represents a new possible strategy for treating diabetic cardiomyopathy.
Mismatch of Sleep and Work Timing and Risk of Type 2 Diabetes
Authors: Vetter Céline , Devore Elizabeth E. , Ramin Cody A. , Speizer Frank E. , Willett Walter C. , Schernhammer Eva S.
Published: June 2015

OBJECTIVE

To examine whether a mismatch between chronotype (i.e., preferred sleep timing) and work schedule is associated with type 2 diabetes risk.

RESEARCH DESIGN AND METHODS

In the Nurses’ Health Study 2, we followed 64,615 women from 2005 to 2011. Newly developed type 2 diabetes was the outcome measure (n = 1,452). A question on diurnal preference ascertained chronotype in 2009; rotating night shift work exposure was assessed regularly since 1989.

RESULTS

Compared with intermediate chronotypes, early chronotypes had a slightly decreased diabetes risk after multivariable adjustment (odds ratio 0.87 [95% CI 0.77–0.98]), whereas no significant association was observed for late chronotypes (1.04 [0.89–1.21]). Among early chronotypes, risk of type 2 diabetes was modestly reduced when working daytime schedules (0.81 [0.63–1.04]) and remained similarly reduced in women working <10 years of rotating night shifts (0.84 [0.72–0.98]). After ≥10 years of shift work exposure, early chronotypes had a nonsignificant elevated diabetes risk (1.15 [0.81–1.63], Ptrend = 0.014). By contrast, among late chronotypes, the significantly increased diabetes risk observed among day workers (1.51 [1.13–2.02]) appeared largely attenuated if their work schedules included night shifts (<10 years: 0.93 [0.76–1.13]; ≥10 years: 0.87 [0.56–1.34]; Ptrend = 0.14). The interaction between chronotype and shift work exposure was significant (Pinteraction = 0.0004). Analyses restricting to incident cases revealed similar patterns.

CONCLUSIONS

In early chronotypes, type 2 diabetes risk increased with increasing duration of shift work exposure, whereas late types had the highest diabetes risk working daytime schedules. These data add to the growing body of evidence that workers could benefit from shift schedules minimizing interference with chronotype-dependent sleep timing.
Development of a clonal equine myoblast cell line capable of terminal differentiation into mature myotubes in vitro
Authors: Naylor Rosie J. , Piercy Richard J.
Published: June 2015

OBJECTIVE To produce a clonal equine myoblast cell line that retains the ability to divide for multiple passages and differentiate into multinucleated myotubes during specific conditions.

SAMPLE Cultured primary equine skeletal muscle-derived cells from a healthy Thoroughbred.

PROCEDURES Cell cultures were transfected by electroporation with a plasmid (pNIT) that expresses the temperature-sensitive simian vacuolating virus 40 large T antigen (TAg), which can be controlled by a doxycycline-responsive promoter. Cells that stably integrated the TAg were selected and expanded to passage 25. For each passage, differentiation and fusion properties of the cells were determined and immunocytochemical analyses were performed to evaluate expression of TAg and other muscle-specific proteins. Optimum conditions that led to cell differentiation into myotubes were also determined.

RESULTS Compared with nontransfected control cells, myogenic, desmin-positive cells expressed the TAg when incubated at 33°C and could be maintained in culture for numerous passages. Reduced expression of TAg was identified in cells incubated at 37°C or when incubated with doxycycline at 33°C. Expression of TAg was not detected when cells were incubated with doxycycline at 37°C, and when serum was withdrawn from the culture medium, those clones differentiated into a pure population of multinucleated myotubes.

CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that production of an immortalized clonal equine skeletal muscle cell line was possible. A clonal equine skeletal muscle cell line will be a valuable in vitro tool for use in equine physiology and disease research.
Comparison of two- and three-times-daily topical ophthalmic application of 0.005% latanoprost solution in clinically normal dogs
Authors: Tofflemire Kyle L. , Whitley Elizabeth M. , Allbaugh Rachel A. , Ben-Shlomo Gil , Robinson Casey C. , Overton Taryn L. , Thiessen Charlotte E. , Evans Erin A. , Griggs Angel N. , Adelman Sara A. , Ludwig Allison L. , Jens Jackie K. , Ellinwood N. Matthew , Peterson Chimene S. , Whitley R. David
Published: June 2015

OBJECTIVE To determine whether 2- or 3-times-daily application of topical ophthalmic 0.005% latanoprost solution is more effective at lowering intraocular pressure (IOP) in clinically normal dogs.

ANIMALS 9 clinically normal dogs.

PROCEDURES For each dog, I drop of latanoprost 0.005% solution was applied to 1 eye every 8 or 12 hours each day for 5 days; the contralateral eye received topical ophthalmic treatment with 1 drop of saline (0.9% NaCl) solution at the times of latanoprost application. Ocular examinations of both eyes were performed every 6 hours starting 48 hours prior to and ending 42 hours after the treatment period. Following a 5-week washout interval, the procedures were repeated but the previously latanoprost-treated eye of each dog received latanoprost application at the alternate frequency.

RESULTS Mean ± SD IOP reduction in the latanoprost-treated eyes was 31 ± 6.9% with 2-times-daily application and 33 ± 8.2% with 3-times-daily application. A 2-way repeated-measures ANOVA revealed significant differences in IOP with contributions by treatment (2 or 3 times daily), time of day (diurnal variation), and individual dog. The maximum mean daily IOP reduction in latanoprost-treated eyes was detected on day 3 of latanoprost treatment in each group. Eyes treated 3 times daily had significantly smaller pupil diameter and greater conjunctival hyperemia than eyes treated 2 times daily.

CONCLUSIONS AND CLINICAL RELEVANCE The clinical importance of the ocular hypotensive effects of 3-times-daily topical ophthalmic application of 0.005% latanoprost solution in dogs with glaucoma warrants investigation.
Effect of exercise on serum markers of muscle inflammation in Spanish Greyhounds
Authors: Lucas Vanesa , Barrera Rafael , Duque Francisco J. , Ruiz Patricia , Zaragoza Concepcion
Published: June 2015

OBJECTIVE To investigate effects of exercise on hematologic and biochemical values (especially markers of inflammation and muscle damage) in Spanish Greyhounds used for hunting without previous training.

ANIMALS 32 Spanish Greyhounds and 31 dogs of other breeds.

PROCEDURES Hematologic variables and concentrations of C-reactive protein (CRP) and other biochemical markers were compared in samples obtained from Spanish Greyhounds 24 hours after exercise (eg, a hunting race) and 2 months after exercise (ie, at rest) and from non–Spanish Greyhounds at rest. All dogs were healthy. Hematologic and biochemical analyses were performed within 24 hours after samples were obtained, and results were compared by means of a Student t test.

RESULTS CRP concentration and muscle enzyme (creatine kinase, lactate dehydrogenase, and aspartate aminotransferase) activities were significantly higher and serum iron concentration was significantly lower for Spanish Greyhounds after exercise than at rest. The WBC and neutrophil counts were significantly higher after exercise then at rest. Plasma alanine transaminase activity and total protein, calcium, and phosphorus concentrations were significantly higher after exercise than at rest. Spanish Greyhounds at rest had higher RBC counts, PCVs, and hemoglobin concentrations and lower WBC, neutrophil, and lymphocyte counts, compared with values for non–Spanish Greyhounds at rest.

CONCLUSIONS AND CLINICAL RELEVANCE Exercise of Spanish Greyhounds without prior training activated an acute-phase response represented by an increase in serum CRP concentration and decrease in serum albumin and iron concentrations. These changes, along with leukocytosis and neutrophilia, were indicative of a subclinical inflammatory state in Spanish Greyhounds.
Effects of azathioprine, 6-mercaptopurine, and 6-thioguanine on canine primary hepatocytes
Authors: LaDuke Kathleen E. , Ehling Sarah , Cullen John M. , Bäumer Wolfgang
Published: June 2015

OBJECTIVE To investigate the cytotoxic effects of azathioprine, 6-mercaptopurine, and 6-thioguanine on canine hepatocytes.

SAMPLE Commercially available cryopreserved canine primary hepatocytes.

PROCEDURES The study consisted of 2 trials. In trial 1, hepatocytes were incubated with azathioprine, 6-mercaptopurine, or 6-thioguanine at 1 of 6 concentrations (0.468, 0.937, 1.875, 3.750, 7.500, or 15.000 μmol/L) for 24, 48, or 72 hours. At each time, cell viability and lactate dehydrogenase (LDH) activity were determined for each thiopurine-concentration combination, and alanine aminotransferase (ALT) activity was determined for cells incubated with each thiopurine at a concentration of 15 μmol/L. In trial 2, hepatocytes were incubated with azathioprine, 6-mercaptopurine, or 6-thioguanine at 1 of 3 concentrations (18.75, 37.50, or 75.00 μmol/L) for 24 hours, after which the free glutathione concentration was determined for each thiopurine-concentration combination and compared with that for hepatocytes incubated without a thiopurine (control).

RESULTS Incubation of hepatocytes with each of the 3 thiopurines adversely affected cell viability in a time- and concentration-dependent manner; however, this decrease in cell viability was not accompanied by a concurrent increase in LDH or ALT activity. Likewise, free glutathione concentration for hepatocytes incubated for 24 hours with supratherapeutic thiopurine concentrations (> 18.75 μmol/L) did not differ significantly from that of control cells.

CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that thiopurines adversely affected the viability of canine hepatocytes in a time- and concentration-dependent manner but had a nonsignificant effect on the LDH and ALT activities and free glutathione depletion of those hepatocytes.
Anti-Aging Performance of Cardanol Grafted onto Polypropylene by Reactive Extrusion
Authors: Lin J.-R. , Lin J.-H. , Chen Q.-H.
Published: June 2015

The cardanol grafted onto polypropylene (CAPP) was prepared by reactive extrusion with polypropylene (PP) and natural renewable cardanol, which could improve the inherent defects of PP such as chemical inertness and hydrophobicity. Moreover, the cardanol grafted onto PP could resolve the degradation of PP during the process of reactive extrusion, storage and application. In this paper, the yield strength, tensile strength, elongation at break of modified and unmodified PPs were tested during the aging process. A possible aging mechanim of PP and anti-aging mechanism of cardanol grafted onto PP were proposed. Results showed that the initiator dicumyl peroxide caused the degradation of PP chains during the aging processing. After being aged for 24 h, the yield strength CAPP0 decreased from 28 MPa to 15 MPa and the elongation at break reduced by 795%. CAPPs possessed outstanding anti-aging performance owing to the cross-linking and entanglement of the side chains of cardanol grafted onto PP. The yield strength, tensile strength and the elongation at break of CAPP5 changed lightly even when it was in long-term irradiation for 480 h. The CAPPs had better anti-aging properties than the mixture of PP and 5% of cardanol. CAPP containing 3% of cardanol could effectively prevent the degradation of the main chain polypropylene.
Competition between α and β Crystallization in Isotactic Polypropylene: Effect of Nucleating Agents Composition
Authors: Wang S.-W. , Leng Y.-T. , Jiang J. , Zheng G.-Q. , Li Q.
Published: June 2015

Based on the different nucleation ability, different contents and proportions of the mixed nucleating agents were melt compounded with pure isotactic polypropylene resins employed in this work, selective β nucleating agent was a compound of pimelic acid and calcium stearate, the α nucleating agent was a type of dibenzylidene sorbitol derivative. The competition attributed to the different type of interactions between a nucleating agent and isotactic polypropylene molecular chains during crystallization was investigated in this research. For a low content of the mixed nucleating agents used, α nucleation dominated the crystallization behavior of isotactic polypropylene, while with an increase of the content of the mixed nucleating agents, the situation was reversed and β nucleation became dominant. In the β dominated region, both of the molecular chain and segmental motions were various with different nucleating agent proportion. Thus, the content and proportion of the components of the nucleating agents were the critical factors in the competition during crystallization.
Thermal and Flexural Properties and Water Absorption of Caulis Spatholobi Residue Fiber Reinforced Biodegradable Poly(propylene carbonate) Composites
Authors: Li W. , Chen F.-Q. , Yin X.-C. , Qu J.-P. , Yan M.
Published: June 2015

This paper investigated and compared the thermal and flexural properties and water absorption of natural caulis spatholobi residue fibers reinforced PPC/CSRF composites. Polypropylene carbonate (PPC) was reinforced by caulis spatholobi residue fibers (CSRF) which had been pretreated by continuous steam explosion. The effect of fiber content (10 to 60 wt%) on the properties and water absorption of PPC/CSRF biodegradable composites was investigated. The thermal properties of PPC/CSRF composites indicated that the addition of CSRF could improve the thermal stability of the composites. The flexural strength and modulus of the composites were found to be improved as the content of fiber increased. From the SEM micrographs, it was found that a small amount of fibers were pulled out on fractured surfaces of the composites, showing good network structure between the fiber and PPC matrix. The water absorption amount of the composites increased with increasing the fiber content. This paper demonstrates that the incorporation of low-cost and biodegradable caulis spatholobi residue fiber into PPC provides a practical way to produce completely biodegradable and cost-competitive composites with good mechanical properties.
Prediction and Validation of Short Fiber Orientation in a Complex Injection Molded Part with Chunky Geometry
Authors: Kleindel S. , Salaberger D. , Eder R. , Schretter H. , Hochenauer C.
Published: June 2015

The paper shows the capability of state-of-the-art models and software to predict the fiber orientation distribution (FOD) on injection molded parts with a complex and thick-walled geometry. Predictions by the standard Folgar-Tucker model and the Reduced Strain Closure model were compared to measurements of the fiber orientation distribution obtained by X-ray Computed Tomography. Measurements and simulations were performed under different processing conditions to investigate the influence of injection velocity and packing pressure on the FOD. It was found that the predicted fiber orientation is in good qualitative agreement with the measurements. The measured orientation shows a distinct shell-core structure with high alignment of the fibers in flow direction in the shell layer and a orientation perpendicular to the flow direction in the core layer. While the orientation in the shell layer is predicted fairly well, a significant deviation is found in the prediction of the orientation in the core layer.
Ice processes and surface ablation in a shallow thermokarst lake in the central Qinghai–Tibetan Plateau
Authors: Huang Wenfeng , Li Runling , Han Hongwei , Niu Fujun , Wu Qingbai , Wang Wenke
Published: June 2015

The Qinghai-Tibetan Plateau (QTP) is characterized by a cold climate and a large number of lakes. The long ice season necessitates study of the widespread ice covers in the region. An unprecedented multidisciplinary field campaign was conducted on lake ice processes in the central QTP during the period 2019–13. The study lake generally froze up in late October or early November, and broke up in mid or late April, with a maximum ice thickness of 50–70 cm. The mass balances at both ice surface and bottom were measured continuously. Significant ice surface sublimation/ablation was detected and accounted for up to 40% of the whole ice thickness over the ice season. A simple heat-transfer model was developed for the surface ice loss. The calculated values were in good agreement with the observations. They also indicated that atmospheric conditions, including low air humidity and prevailing strong winds, are the primary drivers of the ice surface sublimation.
Glacier shrinkage across High Mountain Asia
Authors: Cogley J. Graham
Published: June 2015

An assessment of glacier shrinkage (reduction of area) for all of High Mountain Asia requires a complete compilation of measured rates of change and also a methodology for objective comparison of rates. I present a compilation from 155 publications reporting glacier area changes, and also a methodology that overcomes the main obstacles hindering comparison. Glacier areas are not always assigned uncertainties, and this problem is addressed with an error model derived from published estimates. The problem of discordant survey dates is addressed by interpolating measured areas to fixed dates at pentadal intervals. Interpolation error depends only incoherently on the time span between measurements, but strongly on glacier size: smaller glaciers, in addition to changing more rapidly on average, exhibit more variable rates of change. The overlapping boundaries of study regions are reconciled by mapping all of the information to a 0.5° geographical grid. When coupled with glacier area information from the Randolph Glacier Inventory, the widely observed inverse dependence of shrinkage rates on glacier size shows promise as a tool for treating incomplete spatial coverage. Over High Mountain Asia as a whole from 1960 to 2010, the unweighted average shrinkage rate is –0.57% a–1, but corrections for variable glacier size raise the average to –0.34% a–1, and filling unmeasured gridcells with rates based on size dependence alters the latter estimate to –0.40% a–1. The uncertainties in these rates are large. The Karakoram anomaly is found to be a zonal feature extending well to the east of the Karakoram proper.
5-azacytidine promotes microspore embryogenesis initiation by decreasing global DNA methylation, but prevents subsequent embryo development in rapeseed and barley
Authors: Solís María-Teresa , El-Tantawy Ahmed-Abdalla , Cano Vanesa , Risueño María C. , Testillano Pilar S.
Published: June 2015

Microspores are reprogrammed by stress in vitro toward embryogenesis. This process is an important tool in breeding to obtain double-haploid plants. DNA methylation is a major epigenetic modification that changes in differentiation and proliferation. We have shown changes in global DNA methylation during microspore reprogramming. 5-Azacytidine (AzaC) cannot be methylated and leads to DNA hypomethylation. AzaC is a useful demethylating agent to study DNA dynamics, with a potential application in microspore embryogenesis. This work analyzes the effects of short and long AzaC treatments on microspore embryogenesis initiation and progression in two species, the dicot Brassica napus and the monocot Hordeum vulgare. This involved the quantitative analyses of proembryo and embryo production, the quantification of DNA methylation, 5-methyl-deoxy-cytidine (5mdC) immunofluorescence and confocal microscopy, and the analysis of chromatin organization (condensation/decondensation) by light and electron microscopy. Four days of AzaC treatments (2.5 μM) increased embryo induction, response associated with a decrease of DNA methylation, modified 5mdC, and heterochromatin patterns compared to untreated embryos. By contrast, longer AzaC treatments diminished embryo production. Similar effects were found in both species, indicating that DNA demethylation promotes microspore reprogramming, totipotency acquisition, and embryogenesis initiation, while embryo differentiation requires de novo DNA methylation and is prevented by AzaC. This suggests a role for DNA methylation in the repression of microspore reprogramming and possibly totipotency acquisition. Results provide new insights into the role of epigenetic modifications in microspore embryogenesis and suggest a potential benefit of inhibitors, such as AzaC, to improve the process efficiency in biotechnology and breeding programs.
Pathways to Low Carbon Building: Reflection on the Special Issue
Authors: Moncaster Alice
Published: June 2015

In 2014, this journal invited me to edit a special issue on low carbon building. We put out a call for papers that offered new perspectives, crossing boundaries between technical and social research approaches. The six papers selected and published have emanated from university departments and research centres of Engineering, Architecture, Energy, Design, Urban Planning, Environment, and Sustainable Building. Together they represent a unique and highly readable snapshot of the multiple approaches to this crucial issue—but they also do more; read as a whole they allow the reader to draw new conclusions about the way forward. This editorial draws together and reflects on the six papers, concluding with recommendations for urgent and vital actions for policy makers, professionals and academics.
Cytokine and Adipokine Levels in Patients with Premalignant Oral Lesions or in Patients with Oral Cancer Who Did or Did Not Receive 1α,25-Dihydroxyvitamin D3 Treatment upon Cancer Diagnosis
Authors: Young M. , Levingston Corinne , Johnson Sara
Published: June 2015

Differences in levels of inflammation-modulating cytokines and adipokines in patients with premalignant oral lesions versus in patients that develop squamous cell carcinoma of the head and neck (HNSCC) were assessed. Also assessed was the impact of treating HNSCC patients with the immune regulatory mediator, 1α,25-dihydroxyvitamin D3 [1,25(OH)2D3], on modulators of inflammation. Compared to healthy controls, patients with premalignant oral lesions had increases in their systemic levels of the inflammatory cytokines IL-6 and IL-17, and increases in the adipokine, leptin. However, levels of these pro-inflammatory cytokines and adipokine were reduced in patients with HNSCC. Treatment of HNSCC patients with 1,25(OH)2D3 increased levels of each of the measured immune mediators. Levels of the anti-inflammatory adipokine, adiponectin, were shifted inversely with the levels of the pro-inflammatory cytokines and with leptin. These studies demonstrate heightened immune reactivity in patients with premalignant lesions, which wanes in patients with HNSCC, but which is restored by treatment with 1,25(OH)2D3.
Improving the Ethanol Oxidation Activity of Pt-Mn Alloys through the Use of Additives during Deposition
Authors: Ghavidel Mohammadreza , Easton E.
Published: June 2015

In this work, sodium citrate (SC) was used as an additive to control the particle size and dispersion of Pt-Mn alloy nanoparticles deposited on a carbon support. SC was chosen, since it was the only additive tested that did not prevent Mn from co-depositing with Pt. The influence of solution pH during deposition and post-deposition heat treatment on the physical and electrochemical properties of the Pt-Mn alloy was examined. It was determined that careful control over pH is required, since above a pH of four, metal deposition was suppressed. Below pH 4, the presence of sodium citrate reduced the particle size and improved the particle dispersion. This also resulted in larger electrochemically-active surface areas and greater activity towards the ethanol oxidation reaction (EOR). Heat treatment of catalysts prepared using the SC additive led to a significant enhancement in EOR activity, eclipsing the highest activity of our best Pt-Mn/C prepared in the absence of SC. XRD studies verified the formation of the Pt-Mn intermetallic phase upon heat treatment. Furthermore, transmission electron microscopy studies revealed that catalysts prepared using the SC additive were more resistant to particle size growth during heat treatment.
Hydrological Impacts of the Changes in Simulated Rainfall Fields on Nakanbe Basin in Burkina Faso
Authors: Ibrahim Boubacar , Karambiri Harouna , Polcher Jan
Published: June 2015

Changes in rainfall regime during the last five decades over the West African Sahel have significantly modified the hydrological regime of many rivers with a significant impact on water resources. In this study, the main hydrological processes on the Nakanbe watershed in Burkina Faso are described with two hydrological models: GR2M (lumped and monthly model) and ORCHIDEE (ORganising Carbon and Hydrology In Dynamic EcosystEms) (distributed and half hourly model). Both models were calibrated on the watershed from observed runoff data at Wayen outlet (area of 22,000 km2) for the 1978–1999 period. The mean annual hydrological balance components on the watershed over this period are composed of about 4% of runoff, 10% of groundwater recharge and 86% of actual evapotranspiration for both models. An assessment of the hydrological impacts of the changes in rainfall regime simulated by five regional climate models shows some discrepancies. The hydrological simulations show that the hydrological impacts on the water balance of the watershed come mainly from the changes in rainfall field with regard to the frequency and the intensity of rain events. Compared to the decrease in frequency, it appears that the decrease in the intensity of rain events is much more prejudicial to runoff and groundwater recharge.
On Monotone Embedding in Information Geometry
Authors: Zhang Jun
Published: June 2015

A paper was published (Harsha and Subrahamanian Moosath, 2014) in which the authors claimed to have discovered an extension to Amari's \(\alpha\)-geometry through a general monotone embedding function. It will be pointed out here that this so-called \((F, G)\)-geometry (which includes \(F\)-geometry as a special case) is identical to Zhang's (2004) extension to the \(\alpha\)-geometry, where the name of the pair of monotone embedding functions \(\rho\) and \(\tau\) were used instead of \(F\) and \(H\) used in Harsha and Subrahamanian Moosath (2014). Their weighting function \(G\) for the Riemannian metric appears cosmetically due to a rewrite of the score function in log-representation as opposed to \((\rho, \tau)\)-representation in Zhang (2004). It is further shown here that the resulting metric and \(\alpha\)-connections obtained by Zhang (2004) through arbitrary monotone embeddings is a unique extension of the \(\alpha\)-geometric structure. As a special case, Naudts' (2004) \(\phi\)-logarithm embedding (using the so-called \(\log_\phi\) function) is recovered with the identification \(\rho=\phi, \, \tau=\log_\phi\), with \(\phi\)-exponential \(\exp_\phi\) given by the associated convex function linking the two representations.
Clausius’ Disgregation: A Conceptual Relic that Sheds Light on the Second Law
Authors: Pellegrino Emilio , Ghibaudi Elena , Cerruti Luigi
Published: June 2015

The present work analyzes the cognitive process that led Clausius towards the translation of the Second Law of Thermodynamics into mathematical expressions. We show that Clausius’ original formal expression of the Second Law was achieved by making extensive use of the concept of disgregation, a quantity which has subsequently disappeared from the thermodynamic language. Our analysis demonstrates that disgregation stands as a crucial logical step of such process and sheds light on the comprehension of such fundamental relation. The introduction of entropy—which occurred three years after the first formalization of the Second Law—was aimed at making the Second Law exploitable in practical contexts. The reasons for the disappearance of disgregation, as well as of other “pre-modern” quantities, from the thermodynamics language are discussed.
Effects of Yaw Error on Wind Turbine Running Characteristics Based on the Equivalent Wind Speed Model
Authors: Wan Shuting , Cheng Lifeng , Sheng Xiaoling
Published: June 2015

Natural wind is stochastic, being characterized by its speed and direction which change randomly and frequently. Because of the certain lag in control systems and the yaw body itself, wind turbines cannot be accurately aligned toward the wind direction when the wind speed and wind direction change frequently. Thus, wind turbines often suffer from a series of engineering issues during operation, including frequent yaw, vibration overruns and downtime. This paper aims to study the effects of yaw error on wind turbine running characteristics at different wind speeds and control stages by establishing a wind turbine model, yaw error model and the equivalent wind speed model that includes the wind shear and tower shadow effects. Formulas for the relevant effect coefficients Tc, Sc and Pc were derived. The simulation results indicate that the effects of the aerodynamic torque, rotor speed and power output due to yaw error at different running stages are different and that the effect rules for each coefficient are not identical when the yaw error varies. These results may provide theoretical support for optimizing the yaw control strategies for each stage to increase the running stability of wind turbines and the utilization rate of wind energy.
Improving Transient Stability in a Grid-Connected Squirrel-Cage Induction Generator Wind Turbine System Using a Fuzzy Logic Controller
Authors: Duong Minh , Grimaccia Francesco , Leva Sonia , Mussetta Marco , Le Kim
Published: June 2015

A common problem in wind power plants involves fixed-speed wind turbines. In fact, being equipped with a squirrel-cage induction generator (SCIG), they tend to drain a relevant amount of reactive power from the grid, potentially causing voltage drops and possible voltage instability. To improve SCIG power quality and transient stability, this paper investigates a new control strategy for pitch angle control based on proportional-integral (PI) controller and a fuzzy logic controller (FLC), considering both normal and fault ride-through (FRT) schemes. In the literature, often, the mechanical torque output is assumed constant for a specific wind speed. This might not be accurate, because the mechanical torque-speed typical of a wind turbine depends also on the power coefficient or pitch angle. In this paper, an analytic model of transient stability is proposed using the equivalent circuit of the SCIG and using the concepts of stable and unstable electrical-mechanical equilibrium. The method has been evaluated by comparing the results obtained by the analytic method with the dynamic simulation. The results show that the proposed hybrid controller is effective at smoothing the output power and complying with FRT requirements for SCIG in the power system.