bluuebunny/crossref_metadata_2025 huggingface dataset:
Orta Kariyer Evresinde Bulunan Akademisyenlerin Akademisyenlik Mesleğine Yönelik Görüşleri
Authors: TÜLÜBAŞ Tijen , GÖKTÜRK Şöheyda
Published: January 2019

Akademisyenler ortaya koydukları her türlü çalışma ile üniversitelerin
önemli işlevlerini yerine getirmekte, üniversitelerin bugünü ve geleceğini
belirlemektedirler. Bu bakımdan akademisyenlik mesleğine yönelik çalışmaların
sonuçları her bakımdan önemli katkılar sağlamaktadır. Bu araştırmanın amacı,
orta kariyer evresinde bulunan akademisyenlerin akademisyenlik mesleğine
yönelik görüşlerini irdelemektir. Akademisyenliğin kendi başına bir meslek olup
olmadığı üzerine tartışmalar bulunmakla birlikte, akademisyenliği farklı
uzmanlık alanlarını kapsayan bir meslek olarak tanımlayan çalışmalar sayıca
daha fazladır. Mevcut araştırma akademisyenliği bir meslek olarak ele almakta,
bu mesleği yürütenlerin görüşleri doğrultusunda mesleğin temel özelliklerini
tanımlayacak bulgulara odaklanmaktadır. Araştırma, her bir katılımcının (case)
kendisine has yaşantılarına dayalı olarak akademisyenliğinin algılanan temel
değer ve niteliklerini tanımlamayı hedeflediğinden kolektif araçsal durum
çalışması deseninde tasarlanmış ve devlet üniversitelerinde görev yapmakta
olan, farklı alan uzmanlığına, cinsiyete, unvana ve yaşa sahip 24 orta kariyer
evresi akademisyen ile yürütülmüştür. Orta kariyer evresi mesleki etkinlik
açısından farklı değişim ve tecrübeleri barındıran bir dönem olarak önemli
görülmekle birlikte araştırmalarda göz ardı edilen bir dönem olduğu sıklıkla
belirtilmektedir. Bu bakımdan mevcut çalışmanın orta kariyer evresinde bulunan
akademisyenlerle yürütülmesi tercih edilmiştir. Araştırmanın verileri açık-uçlu
yarı yapılandırılmış görüşme formu kullanılarak elde edilmiş, elde edilen
veriler içerik analizine tabi tutulmuştur. İçerik analizinde toplan yedi
kategori elde edilmiştir. Araştırma bulguları; akademisyenlerin mesleği, iki
yönlü bir meslek, usta-çırak ilişkisiyle edinilen bir meslek, edinilmesi ve
yürütülmesi zor bir meslek, hayatın her yerinde olan bir meslek, para için
yapılmayacak bir meslek, özdenetime dayalı bir meslek ve toplumsal saygınlığı
olan bir meslek olarak tanımladıklarını göstermektedir. Katılımcıların
akademisyenlik mesleğinin özü ile ilgili ortaya koydukları bu görüşlerin,
akademisyenlerin çalışma yaşantılarına yönelik yapılacak düzenlemelerde dikkate
alınması, alınan kararların uygulamaya konulması ve etkili sonuçlar
üretebilmesi bakımından önemlidir.
Ters Yüz Öğrenme Yaklaşımının Öğrencilerin Akademik Başarılarına Etkisi: Mikroişlemci/Mikrodenetleyiciler II Dersinin Uygulaması
Authors: DEVECİ TOPAL Arzu , AKHİSAR Ümmühan
Published: January 2019

Internet teknolojisinin hayatımıza girmesiyle birlikte yeni öğrenme ve
öğretme yaklaşımları ortaya çıkmaya başlamıştır. Bu yaklaşımlardan biri olan
ters yüz öğrenme modelinde öğretmen önceden belirlediği materyalleri
öğrencileri ile ders öncesinde paylaşmakta ve ilgili konu öğretimi bu kaynaklar
vasıtasıyla sınıf dışında eş zamanlı olmayan biçimde gerçekleştirilmekte; sınıf
içinde ise etkileşimli, aktif ve işbirlikli problem çözme etkinlikleri ve konu
pekiştirme çalışmaları uygulanmaktadır. Bu araştırmada amaç,
“Mikroişlemciler/Mikrodenetleyiciler II” dersinin öğrenme süreçlerinde uygulama
etkinliklerinin artırılarak daha etkili ve kalıcı öğrenmenin gerçekleşmesinde
ters yüz edilmiş öğrenme modelinin öğrenci başarısına etkisini ve öğrencilerin
bu yaklaşım hakkındaki düşüncelerini belirlemektir. Çalışmada
nicel ve nitel veri toplama yöntemleri ile gerçek deneme modellerinden biri
olan son test kontrol gruplu model kullanılmıştır.  Bu çalışmanın örneklemini Kocaeli
Üniversitesi Hereke Meslek Yüksekokulu Elektronik Teknolojisi Programında
2016-2017 eğitim öğretim yılında öğrenim gören ve derse devam eden 67 öğrenci
oluşturmaktadır. Derse devam eden 34 öğrenci deney grubuna, 33 öğrenci kontrol grubuna rastgele
atanmıştır. Bu amaçla tersyüz öğrenme modeline yönelik Moodle öğrenme yönetim
sistemine uyumlu SCORM paketler hazırlanmış ve kısa sınavlar oluşturulmuştur.
Öğrencilerin akademik başarılarını ölçmek için başarı testi geliştirilmiş ve
nitel veri toplama aracı olarak yarı yapılandırılmış görüşme formu aracılığıyla
odak grup görüşmesi yapılmıştır. Elde edilen bulgulara göre ters yüz öğrenme
ortamının öğrencilerin akademik başarısına anlamlı bir etkisinin olmadığı
belirlenmiştir. Öte yandan öğrenciler ters yüz öğrenme ortamı hakkında olumlu
görüş belirtmiş ve bu tür bir ortamın öğrenmelerine katkı sağlayacağını ifade
etmişlerdir
Agency, identity and learning at turning points in women’s lives
Authors: Biasin Chiara , Evans Karen
Published: January 2019

This paper discusses the ways in which women aged 50, in two different cultural contexts (United Kingdom and Italy) narrate and portray turning points in their life course. Particular emphasis is put on the relationships between identity, learning and agency that emerge through work, family and life experiences. The reference paradigm is adopted from Narrative Learning Theory and the approach is qualitative and comparative in analysing the participant’s voice. For the UK sample, the data sources are 16 semi-structured interviews, including drawings representing the life course, selected from the study deposited in the UK Archives Data under the “Social Participation and Identity” project; for the Italian sample, the data sources are 28 semistructured interviews and drawings, based on the same selected items of the UK interviews and provided by women living in the North-East of Italy. This study will show how women’s representations of their life course and of turning points in their lives reveal different propensities to reflect on and learn from their own lives. The comparative perspective highlights, through two-level analysis (micro and macro) and by contrasting cultural, relational and social contexts, variations in ways these women are enabled or restricted in moving their lives forward. The research also contributes to methodological insight into the use of drawings in elucidating life course narratives.
A Generalized State-Space Aeroservoelastic Model Based on Tangential Interpolation
Authors: Quero David , Vuillemin Pierre , Poussot-Vassal Charles
Published: January 2019

In this work, a new approach for the generation of a generalized state-space aeroservoelastic model based on tangential interpolation is presented. The resulting system of differential algebraic equations (DAE) is reduced to a set of ordinary differential equations (ODE) by residualization of the non-proper part of the transfer function matrix. The generalized state-space is of minimal order and allows for the application of the force summation method (FSM) for the aircraft loads recovery. Compared to the classical rational function approximation (RFA) approach, the presented method provides a minimal order realization with exact interpolation of the unsteady aerodynamic forces in tangential directions, avoiding any selection of poles (lag states). The new approach is applied first for the generation of an aerodynamic model for the bidimensional unsteady incompressible flow in the time domain. Next, an application on the generation of an aeroservoelastic model for loads evaluation of the flutter reduced order assessment (FERMAT) model under atmospheric disturbances is done, showing an excellent agreement with the reference model in the frequency domain. The proposed aeroservoelastic model of minimal order is suited for loads analysis and multivariable control design, and an application to a gust loads alleviation (GLA) strategy is shown.
S-Allylmercapro-N-Acetylcysteine Attenuates the Oxidation-Induced Lens Opacification and Retinal Pigment Epithelial Cell Death In Vitro
Authors: Savion Naphtali , Dahamshi Samia , Morein Milana , Kotev-Emeth Shlomo
Published: January 2019

The capacity of S-Allylmercapto-N-acetylcysteine (ASSNAC) to protect human retinal pigment epithelial (RPE) cells (line ARPE-19) and porcine lenses from oxidative stress was studied. Confluent ARPE-19 cultures were incubated with ASSNAC or N-acetyl-cysteine (NAC) followed by exposure to oxidants and glutathione level and cell survival were determined. Porcine lenses were incubated with ASSNAC and then exposed to H2O2 followed by lens opacity measurement and determination of glutathione (reduced (GSH) and oxidized (GSSG)) in isolated lens adhering epithelial cells (lens capsule) and fiber cells consisting the lens cortex and nucleus (lens core). In ARPE-19 cultures, ASSNAC (0.2 mM; 24 h) increased glutathione level by 2–2.5-fold with significantly higher increase in GSH compared to NAC treated cultures. Similarly, ex-vivo exposure of lenses to ASSNAC (1 mM) significantly reduced the GSSG level and prevented H2O2 (0.5 mM)-induced lens opacification. These results demonstrate that ASSNAC up-regulates glutathione level in RPE cells and protects them from oxidative stress-induced cell death as well as protects lenses from oxidative stress-induced opacity. Further validation of these results in animal models may suggest a potential use for ASSNAC as a protective therapy in retinal degenerative diseases as well as in attenuation of oxidative stress-induced lens opacity.
Experimental Study on Vibration Control of Suspended Piping System by Single-Sided Pounding Tuned Mass Damper
Authors: Tan Jie , Michael Ho Siu Chun , Zhang Peng , Jiang Jinwei
Published: January 2019

Suspended piping systems often suffer from severe damages when subjected to seismic excitation. Due to the high flexibility of the piping systems, reducing their displacement is important for the prevention of damage during times of disaster. A solution to protecting piping systems during heavy excitation is the use of the emerging pounding tuned mass damper (PTMD) technology. In particular, the single-sided PTMD combines the advantages of the tuned mass damper (TMD) and the impact damper, including the benefits of a simple design and rapid, efficient energy dissipation. In this paper, two single-sided PTMDs (spring steel-type PTMD and simple pendulum-type PTMD) were designed and fabricated. The dampers were tested and compared with the traditional TMD for mitigating free vibration and forced vibration. In the free vibration experiment, both PTMDs suppressed vibrations much faster than the TMD. For the forced vibration test, the frequency response of the piping system was obtained for three conditions: without control, with TMD control, and with PTMD control. These novel results demonstrate that the single-sided PTMD is a cost-effective method for efficiently and passively mitigating the vibration of suspended piping systems. Thus, the single-sided PTMD will be an important tool for increasing the resilience of structures as well as for improving the safety of their occupants.
Broadband Photo-Excited Coherent Acoustic Frequency Combs and Mini-Brillouin-Zone Modes in a MQW-SESAM Structure
Authors: Li Changxiu , Gusev Vitalyi , Dimakis Emmanouil , Dekorsy Thomas , Hettich Mike
Published: January 2019

A multiple quantum-well semiconductor saturable absorber mirror (MQW-SESAM) structure has been investigated by femtosecond pump-probe laser spectroscopy at a central wavelength of around 1050 nm. Coherent acoustic phonons are generated and detected over a wide frequency range from ~15 GHz to ~800 GHz. In the optical absorption region, i.e., in the multiple quantum wells (In0.27Ga0.73As), acoustic frequency combs centered at ~365 GHz, with a comb spacing of ~33 GHz, are generated. Most importantly, in the transparent region, i.e., in the distributed Bragg reflector, which is formed by a non-doped long-period semiconductor GaAs/Al0.95Ga0.05As superlattice, the mini-Brillouin-zone center, as well as zone-edge acoustic modes, are observed. The mini-zone-center modes with a fundamental frequency of 32 GHz can be attributed to the spatial modulation of the pump optical interference field with a period very close to that of the distributed Bragg reflector, in combination with the periodic spatial modulation of the electrostriction coefficient in the distributed Bragg reflector. The excitation of mini-zone-edge modes is attributed to the stimulated subharmonic decay of the fundamental center modes. Their subsequent back-folding to the mini-Brillouin-zone center makes them Raman active for the probe light.
Astrophotonic Spectrographs
Authors: Gatkine Pradip , Veilleux Sylvain , Dagenais Mario
Published: January 2019

Astrophotonics is the application of photonic technologies to channel, manipulate, and disperse light from one or more telescopes to achieve scientific objectives in astronomy in an efficient and cost-effective way. Utilizing photonic advantage for astronomical spectroscopy is a promising approach to miniaturizing the next generation of spectrometers for large telescopes. It can be primarily attained by leveraging the two-dimensional nature of photonic structures on a chip or a set of fibers, thus reducing the size of spectroscopic instrumentation to a few centimeters and the weight to a few hundred grams. A wide variety of astrophotonic spectrometers is currently being developed, including arrayed waveguide gratings (AWGs), photonic echelle gratings (PEGs), and Fourier-transform spectrometer (FTS). These astrophotonic devices are flexible, cheaper to mass produce, easier to control, and much less susceptible to vibrations and flexure than conventional astronomical spectrographs. The applications of these spectrographs range from astronomy to biomedical analysis. This paper provides a brief review of this new class of astronomical spectrographs.
Polyurethane-Supported Graphene Oxide Foam Functionalized with Carbon Dots and TiO2 Particles for Photocatalytic Degradation of Dyes
Authors: Liu Tianjiao , Sun Shuwei , Zhou Lin , Li Peng , Su Zhiqiang , Wei Gang
Published: January 2019

The design and optimal synthesis of functional nanomaterials can meet the requirements of energy and environmental science. As a typical photocatalyst, TiO2 can be used to degrade dyes into non-toxic substances. In this work, we demonstrated the in-situ hydrothermal synthesis of carbon quantum dots (CQDs)-modified TiO2 (CQDs/TiO2) particles, and the subsequent fabrication of three-dimensional (3D) graphene oxide (GO) foam doped with CQDs/TiO2 via a facile strategy. By making full use of the up-conversion characteristics of CQDs, the synthesized CQDs/TiO2 exhibited high catalytic activity under visible light. In order to recover the photocatalyst conveniently, CQDs/TiO2 and GO were mixed by ultrasound and loaded on 3D polyurethane foam (PUF) by the multiple impregnation method. It was found that GO, CQDs/TiO2, and PUF reveal synergistic effects on the dye adsorption and photocatalytic degradation processes. The fabricated 3D CQDs/TiO2/GO foam system with a stable structure can maintain a high photocatalytic degradation efficiency after using at least five times. It is expected that the fabricated 3D materials will have potential applications in the fields of oil water separation, the removal of oils, and the photothermal desalination of seawater.
Improved Defect Detection Using Adaptive Leaky NLMS Filter in Guided-Wave Testing of Pipelines
Authors: Nakhli Mahal Houman , Yang Kai , Nandi Asoke K.
Published: January 2019

Ultrasonic guided wave (UGW) testing of pipelines allows long range assessments of pipe integrity from a single point of inspection. This technology uses a number of arrays of transducers, linearly placed apart from each other to generate a single axisymmetric wave mode. The general propagation routine of the device results in a single time domain signal, which is then used by the inspectors to detect the axisymmetric wave for any defect location. Nonetheless, due to inherited characteristics of the UGW and non-ideal testing conditions, non-axisymmetric (flexural) waves will be transmitted and received in the tests. This adds to the complexity of results’ interpretation. In this paper, we implement an adaptive leaky normalized least mean square (NLMS) filter for reducing the effect of non-axisymmetric waves and enhancement of axisymmetric waves. In this approach, no modification in the device hardware is required. This method is validated using the synthesized signal generated by a finite element model (FEM) and real test data gathered from laboratory trials. In laboratory trials, six different sizes of defects with cross-sectional area (CSA) material loss of 8% to 3% (steps of 1%) were tested. To find the optimum frequency, several excitation frequencies in the region of 30–50 kHz (steps of 2 kHz) were used. Furthermore, two sets of parameters were used for the adaptive filter wherein the first set of tests the optimum parameters were set to the FEM test case and, in the second set of tests, the data from the pipe with 4% CSA defect was used. The results demonstrated the capability of this algorithm for enhancing a defect’s signal-to-noise ratio (SNR).
Calligraphic Glass: Making Marks with Glass
Authors: Tani Ayako
Published: January 2019

Calligraphic glass is one of the newer developments in contemporary glass art. The long-standing tradition of calligraphy is a rich source of inspiration for the glass artist, glass being a relatively new material for spontaneous mark-making. The investigation of the calligraphic quality of artworks ultimately leads to a discussion of human body movement, because mark-making is fundamentally a kinetic exercise. Often, the artist’s psychological and physical state is more important than the resultant marks. Building upon my doctoral research, which introduced the basic idea and techniques of ‘calligraphic lampworking’, this paper develops the discussion mainly regarding how the artist’s body movement may be manifested as spatial traces made from glass lines.
Aurora A Protein Kinase: To the Centrosome and Beyond
Authors: Magnaghi-Jaulin Laura , Eot-Houllier Grégory , Gallaud Emmanuel , Giet Régis
Published: January 2019

Accurate chromosome segregation requires the perfect spatiotemporal rearrangement of the cellular cytoskeleton. Isolated more than two decades ago from Drosophila, Aurora A is a widespread protein kinase that plays key roles during cell division. Numerous studies have described the localisation of Aurora A at centrosomes, the mitotic spindle, and, more recently, at mitotic centromeres. In this review, we will summarise the cytoskeletal rearrangements regulated by Aurora A during cell division. We will also discuss the recent discoveries showing that Aurora A also controls not only the dynamics of the cortical proteins but also regulates the centromeric proteins, revealing new roles for this kinase during cell division.
Overcoming Intrinsic and Acquired Cetuximab Resistance in RAS Wild-Type Colorectal Cancer: An In Vitro Study on the Expression of HER Receptors and the Potential of Afatinib
Authors: De Pauw Ines , Lardon Filip , Van den Bossche Jolien , Baysal Hasan , Pauwels Patrick , Peeters Marc , Vermorken Jan Baptist , Wouters An
Published: January 2019

The epidermal growth factor receptor (EGFR) is an important therapeutic target in colorectal cancer (CRC). After the initial promising results of EGFR-targeted therapies such as cetuximab, therapeutic resistance poses a challenging problem and limits the success of effective anti-EGFR cancer therapies in the clinic. In order to overcome resistance to these EGFR-targeted therapies, new treatment options are necessary. The objective of this study was to investigate the expression of human epidermal growth factor (HER) receptors and the efficacy of afatinib, a second-generation irreversible EGFR-tyrosine kinase inhibitor, in RAS wild-type CRC cell lines with different cetuximab sensitivities. CRC cell lines with different sensitivities to cetuximab showed rather low EGFR expression but high HER2 and HER3 expression. These results were in line with the The Cancer Genome Atlas (TCGA) data from CRC patients, where higher mRNA levels of HER2 and HER3 were also detected compared to EGFR. Therefore, the targets of afatinib were indeed expressed on the CRC cell lines used in this study and in CRC patients. Furthermore, cetuximab resistance had no significant influence on the expression levels of HER receptors in CRC cell lines (p ≥ 0.652). This study also demonstrated that afatinib was able to induce a concentration-dependent cytotoxic effect in RAS wild-type CRC cell lines with different cetuximab sensitivities. Neither cetuximab resistance (p = 0.233) nor hypoxia (p = 0.157) significantly influenced afatinib’s cytotoxic effect. In conclusion, our preclinical data support the hypothesis that treatment with afatinib might be a promising novel therapeutic strategy for CRC patients experiencing intrinsic and acquired cetuximab resistance.
Mood Disorders, Accelerated Aging, and Inflammation: Is the Link Hidden in Telomeres?
Authors: Squassina Alessio , Pisanu Claudia , Vanni Roberta
Published: January 2019

Mood disorders are associated with an increased risk of aging-related diseases, which greatly contribute to the excess morbidity and mortality observed in affected individuals. Clinical and molecular findings also suggest that mood disorders might be characterized by a permanent state of low-grade inflammation. At the cellular level, aging translates into telomeres shortening. Intriguingly, inflammation and telomere shortening show a bidirectional association: a pro-inflammatory state seems to contribute to aging and telomere dysfunction, and telomere attrition is able to induce low-grade inflammation. Several independent studies have reported shorter telomere length and increased levels of circulating inflammatory cytokines in mood disorders, suggesting a complex interplay between altered inflammatory–immune responses and telomere dynamics in the etiopathogenesis of these disorders. In this review, we critically discuss studies investigating the role of telomere attrition and inflammation in the pathogenesis and course of mood disorders, and in pharmacological treatments with psychotropic medications.
Preliminary Equipment Design for On-Board Hydrogen Production by Steam Reforming in Palladium Membrane Reactors
Authors: Holgado Marina , Alique David
Published: January 2019

Hydrogen, as an energy carrier, can take the main role in the transition to a new energy model based on renewable sources. However, its application in the transport sector is limited by its difficult storage and the lack of infrastructure for its distribution. On-board H2 production is proposed as a possible solution to these problems, especially in the case of considering renewable feedstocks such as bio-ethanol or bio-methane. This work addresses a first approach for analyzing the viability of these alternatives by using Pd-membrane reactors in polymer electrolyte membrane fuel cell (PEM-FC) vehicles. It has been demonstrated that the use of Pd-based membrane reactors enhances hydrogen productivity and provides enough pure hydrogen to feed the PEM-FC requirements in one single step. Both alternatives seem to be feasible, although the methane-based on-board hydrogen production offers some additional advantages. For this case, it is possible to generate 1.82 kmol h−1 of pure H2 to feed the PEM-FC while minimizing the CO2 emissions to 71 g CO2/100 km. This value would be under the future emissions limits proposed by the European Union (EU) for year 2020. In this case, the operating conditions of the on-board reformer are T = 650 °C, Pret = 10 bar and H2O/CH4 = 2.25, requiring 1 kg of catalyst load and a membrane area of 1.76 m2.
Fluorescence-Based Detection of Benzene, Toluene, Ethylbenzene, Xylene, and Cumene (BTEXC) Compounds in Fuel-Contaminated Snow Environments
Authors: DiScenza Dana J. , Intravaia Lauren E. , Healy Anna , Dubrawski Sage B. , Levine Mindy
Published: January 2019

Reported herein is the sensitive and selective cyclodextrin-promoted fluorescence detection of benzene, toluene, ethylbenzene, xylene, and cumene (BTEXC) fuel components in contaminated snow samples collected from several locations in the state of Rhode Island. This detection method uses cyclodextrin as a supramolecular scaffold to promote analyte-specific, proximity-induced fluorescence modulation of a high-quantum-yield fluorophore, which leads to unique fluorescence responses for each cyclodextrin-analyte-fluorophore combination investigated and enables unique pattern identifiers for each analyte using linear discriminant analysis (LDA). This detection method operates with high levels of sensitivity (sub-micromolar detection limits), selectivity (100% differentiation between structurally similar compounds, such as ortho-, meta-, and para-xylene isomers), and broad applicability (for different snow samples with varying chemical composition, pH, and electrical conductivity). The high selectivity, sensitivity, and broad applicability of this method indicate significant potential in the development of practical detection devices for aromatic toxicants in complex environments.
Mesoporous Silica SBA-15 Particles in a Detergent Solution as Abrasive and Coating Material for Household Care Cleaning Products
Authors: Plomaritis Athanasios , Giliopoulos Dimitris , Triantafyllidis Konstantinos , Kostoglou Margaritis , Karapantsios Thodoris D.
Published: January 2019

Cleaning products have improved a lot in the last century. The reason for this improvement is not only the use of new surfactants, but also the use of additives that either increase the efficiency of surfactants or act as abrasive agents that increase the mechanical friction during the cleaning process. In this study mesoporous silica (SBA-15) particles are suggested as abrasive additives to a reference detergent as they have a quite soft structure and their shape can act as micro-sponge to collect large amounts of dirt. Indeed, SBA-15 performs very well when added to the detergent, decreasing the effort for primary cleaning of a surface. Furthermore, the properties of the coating layer left behind after primary cleaning with SBA-15 are also examined (i.e., secondary cleaning). It is found that SBA-15 offers no benefit for secondary cleaning. In order to explain this finding, the effect of SBA-15 on the wetting properties of different substrates is studied. It is seen that the SBA-15 coating layer is not uniform. Furthermore, it is seen that dirt is capable of pushing away the coating layer and occupying a large area on the substrate. Contact angle measurements indicate that the substrates become more omniphilic in the presence of SBA-15 coating.
After the Fall: Legacy Effects of Biogenic Structure on Wind-Generated Ecosystem Processes Following Mussel Bed Collapse
Authors: Commito John A. , Jones Brittany R. , Jones Mitchell A. , Winders Sondra E. , Como Serena
Published: January 2019

Blue mussels (Mytilus edulis) are ecosystem engineers with strong effects on species diversity and abundances. Mussel beds appear to be declining in the Gulf of Maine, apparently due to climate change and predation by the invasive green crab, Carcinus maenas. As mussels die, they create a legacy of large expanses of shell biogenic structure. In Maine, USA, we used bottom traps to examine effects of four bottom cover types (i.e., live mussels, whole shells, fragmented shells, bare sediment) and wind condition (i.e., days with high, intermediate, and low values) on flow-related ecosystem processes. Significant differences in transport of sediment, meiofauna, and macrofauna were found among cover types and days, with no significant interaction between the two factors. Wind condition had positive effects on transport. Shell hash, especially fragmented shells, had negative effects, possibly because it acted as bed armor to reduce wind-generated erosion and resuspension. Copepods had the greatest mobility and shortest turnover times (0.15 d), followed by nematodes (1.96 d) and the macrofauna dominant, Tubificoides benedeni (2.35 d). Shell legacy effects may play an important role in soft-bottom system responses to wind-generated ecosystem processes, particularly in collapsed mussel beds, with implications for recolonization, connectivity, and the creation and maintenance of spatial pattern.
Pliocene Origin, Ice Ages and Postglacial Population Expansion Have Influenced a Panmictic Phylogeography of the European Bee-Eater Merops apiaster
Authors: Carneiro de Melo Moura Carina , Bastian Hans-Valentin , Bastian Anita , Wang Erjia , Wang Xiaojuan , Wink Michael
Published: January 2019

Oscillations of periods with low and high temperatures during the Quaternary in the northern hemisphere have influenced the genetic composition of birds of the Palearctic. During the last glaciation, ending about 12,000 years ago, a wide area of the northern Palearctic was under lasting ice and, consequently, breeding sites for most bird species were not available. At the same time, a high diversity of habitats was accessible in the subtropical and tropical zones providing breeding grounds and refugia for birds. As a result of long-term climatic oscillations, the migration systems of birds developed. When populations of birds concentrated in refugia during ice ages, genetic differentiation and gene flow between populations from distinct areas was favored. In the present study, we explored the current genetic status of populations of the migratory European bee-eater. We included samples from the entire Palearctic-African distribution range and analyzed them via mitochondrial and nuclear DNA markers. DNA data indicated high genetic connectivity and panmixia between populations from Europe, Asia and Africa. Negative outcomes of Fu’s Fs and Tajima’s D tests point to recent expansion events of the European bee-eater. Speciation of Merops apiaster started during the Pliocene around three million years ago (Mya), with the establishment of haplotype lineages dated to the Middle Pleistocene period circa 0.7 Mya. M. apiaster, which breed in Southern Africa are not distinguished from their European counterparts, indicating a recent separation event. The diversification process of the European bee-eater was influenced by climatic variation during the late Tertiary and Quaternary. Bee-eaters must have repeatedly retracted to refugia in the Mediterranean and subtropical Africa and Asia during ice ages and expanded northwards during warm periods. These processes favored genetic differentiation and repeated lineage mixings, leading to a genetic panmixia, which we still observe today.
AnScalable Matrix Computing Unit Architecture for FPGA, and SCUMO User Design Interface
Authors: Abbaszadeh Asgar , Iakymchuk Taras , Bataller-Mompeán Manuel , Francés-Villora Jose V. , Rosado-Muñoz Alfredo
Published: January 2019

High dimensional matrix algebra is essential in numerous signal processing and machine learning algorithms. This work describes a scalable square matrix-computing unit designed on the basis of circulant matrices. It optimizes data flow for the computation of any sequence of matrix operations removing the need for data movement for intermediate results, together with the individual matrix operations’ performance in direct or transposed form (the transpose matrix operation only requires a data addressing modification). The allowed matrix operations are: matrix-by-matrix addition, subtraction, dot product and multiplication, matrix-by-vector multiplication, and matrix by scalar multiplication. The proposed architecture is fully scalable with the maximum matrix dimension limited by the available resources. In addition, a design environment is also developed, permitting assistance, through a friendly interface, from the customization of the hardware computing unit to the generation of the final synthesizable IP core. For N × N matrices, the architecture requires N ALU-RAM blocks and performs O ( N 2 ) , requiring N 2 + 7 and N + 7 clock cycles for matrix-matrix and matrix-vector operations, respectively. For the tested Virtex7 FPGA device, the computation for 500 × 500 matrices allows a maximum clock frequency of 346 MHz, achieving an overall performance of 173 GOPS. This architecture shows higher performance than other state-of-the-art matrix computing units.
Specific Energy Consumption/Use (SEC) in Energy Management for Improving Energy Efficiency in Industry: Meaning, Usage and Differences
Authors: Lawrence Akvile , Thollander Patrik , Andrei Mariana , Karlsson Magnus
Published: January 2019

Although several research studies have adopted specific energy consumption (SEC) as an indicator of the progress of improved energy efficiency, publications are scarce on critical assessments when using SEC. Given the increasing importance of monitoring improved industrial energy efficiency and the rising popularity of SEC as an energy key performance indicator (e-KPI), an in-depth analysis and problematization on the pros and cons of using SEC would appear to be needed. The aim of this article is to analyse SEC critically in relation to industrial energy efficiency. By using SEC in the pulp and paper industry as an example, the results of this exploratory study show that although SEC is often used as an e-KPI in industry, the comparison is not always straightforward. Challenges emanate from a lack of information about how SEC is calculated. It is likely that SEC is an optimal e-KPI within the same study, when all deployed SECs are calculated in the same way, and with the same underlying assumptions. However, before comparing SEC with other studies, it is recommended that the assumptions on which calculations are based should be scrutinized in order to ensure the validity of the comparisons. The paper remains an important contribution in addition to the available handbooks.
Node Temperature of the Coupled High-Low Energy Grade Flus Gas Waste Heat Recovery System
Authors: Liu Jiayou , Sun Fengzhong
Published: January 2019

Coupled high-low energy grade flus gas waste heat recovery systems (CWHRS) have been applied in power plants to improve unit efficiency. In this study, to evaluate the rationality of waste heat recovery, the energy-grade balance coefficient (EBC) of the CWHRS was derived using the theory of heat balance, exergy balance and energy grade balance. The inlet flue gas temperature (IFT) of the low-temperature economizer was defined as the node temperature of the CWHRS. The optimal node temperature (ONT) was optimal when the absolute value of the EBC was the smallest. The exergy efficiency and EBC of the system installed on a supercritical 600 MW unit were calculated and the result shows that the ONT of the system was about 115 °C, the ONT decreased from about 135 °C to about 113 °C when the IFT increased from 335 °C to 380 °C and the ONT decreased from about 144 °C to about 113 °C when the inlet air temperature increased from −10 °C to 35 °C. The node temperature is recommended as an adjusting parameter of CWHRS to ensure the effect of waste heat recovery.
Study on the Comprehensive Benefit Evaluation of Transnational Power Networking Projects Based on Multi-Project Stakeholder Perspectives
Authors: Zhao Yunqi , Xiang Jing , Xu Jiaming , Li Jinying , Zhang Ning
Published: January 2019

Interconnection of transnational power grids plays an important role in realizing the optimal allocation of energy resources. It can also deepen regional economic cooperation, achieve energy conservation and emission reduction, and improve people’s livelihood. This paper constructs a comprehensive benefit evaluation index system for transnational power networking projects which is suitable for the four stakeholders of investors, international lending institutions, sending-oriented states, and receiving-oriented states. Therefore, on the basis of this index system, this paper adopted the weight determination method based on the order relation method and Gini coefficient method to synthesize subjective and objective information. Then the comprehensive benefit evaluation of such projects was carried out by matter-element extension model with grey relational projection value. Therefore, the problem with the Euclid approach degree leading to a low discrimination of many samples to be evaluated was effectively solved. The final empirical analysis results showed that the focus and evaluation results of the comprehensive benefits of such projects from the perspective of different stakeholders were quite different. The results of comprehensive benefit evaluation will improve the accuracy of decision-making and the objectivity of evaluation, so as to provide decision-making references for different stakeholders.
Process Technologies and Projects for BioLPG
Authors: Johnson Eric
Published: January 2019

Liquified petroleum gas (LPG)—currently consumed at some 300 million tonnes per year—consists of propane, butane, or a mixture of the two. Most of the world’s LPG is fossil, but recently, BioLPG has been commercialized as well. This paper reviews all possible synthesis routes to BioLPG: conventional chemical processes, biological processes, advanced chemical processes, and other. Processes are described, and projects are documented as of early 2018. The paper was compiled through an extensive literature review and a series of interviews with participants and stakeholders. Only one process is already commercial: hydrotreatment of bio-oils. Another, fermentation of sugars, has reached demonstration scale. The process with the largest potential for volume is gaseous conversion and synthesis of two feedstocks, cellulosics or organic wastes. In most cases, BioLPG is produced as a byproduct, i.e., a minor output of a multi-product process. BioLPG’s proportion of output varies according to detailed process design: for example, the advanced chemical processes can produce BioLPG at anywhere from 0–10% of output. All these processes and projects will be of interest to researchers, developers and LPG producers/marketers.
Creep Behaviors of Methane Hydrate-Bearing Frozen Sediments
Authors: Li Yanghui , Wu Peng , Sun Xiang , Liu Weiguo , Song Yongchen , Zhao Jiafei
Published: January 2019

Creep behaviors of methane hydrate-bearing frozen specimens are important to predict the long-term stability of the hydrate-bearing layers in Arctic and permafrost regions. In this study, a series of creep tests were conducted, and the results indicated that: (1) higher deviator stress (external load) results in larger initial strain, axial strain, and strain rate at a specific elapsed time. Under low deviator stress levels, the axial strain is not large and does not get into the tertiary creep stage in comparison with that under high deviator stress, which can be even up to 35% and can cause failure; (2) both axial strain and strain rate of methane hydrate-bearing frozen specimens increase with the enhancement of deviator stress, the decrease of confining pressure, and the decrease of temperature; (3) the specimens will be damaged rather than in stable creep stage during creeping when the deviator stress exceeds the quasi-static strength of the specimens.
A Multi-Layer Coordinated Control Scheme to Improve the Operation Friendliness of Grid-Connected Multiple Microgrids
Authors: Wu Pan , Huang Wentao , Tai Nengling , Ma Zhoujun , Zheng Xiaodong , Zhang Yong
Published: January 2019

Multiple microgrids (MMGs) are clusters of interconnected microgrids that have great potential for integrating a large number of distributed renewable energies (DREs). The grid-connected control scheme is important for the exploration of the MMGs’ operation potential. In this paper, a multi-layer coordinated control scheme for DC interconnected MMGs is proposed to optimize their operation and improve their operation friendliness. An adaptive droop control method is designed for the DC connection interfaces of the MMGs to adaptively manage the power exchange among the sub-microgrids. Meanwhile, the strategy of power fluctuation suppression is developed for the hybrid energy storage system (HESS) in the MMGs. The coordination among the sub-microgrids and the HESS is then clarified by the proposed control scheme to optimize the AC tie-line power and make the MMGs a highly coordinated collective. A case study is performed in PSCAD/EMTDC based on the demonstration project in Guangxi, China. The results show that the proposed multi-layer coordinated control scheme realizes the coordinated operation of the MMGs, fully exploits the complementarity of the MMGs, and improves the operation friendliness among the sub-microgrids and the utility grid. Thus the integration and utilization of a large number of DREs is enhanced.
Applying the Smart Grid Architecture Model for Designing and Validating System-of-Systems in the Power and Energy Domain: A European Perspective
Authors: Uslar Mathias , Rohjans Sebastian , Neureiter Christian , Pröstl Andrén Filip , Velasquez Jorge , Steinbrink Cornelius , Efthymiou Venizelos , Migliavacca Gianluigi , Horsmanheimo Seppo , Brunner Helfried , Strasser Thomas I.
Published: January 2019

The continuously increasing complexity of modern and sustainable power and energy systems leads to a wide range of solutions developed by industry and academia. To manage such complex system-of-systems, proper engineering and validation approaches, methods, concepts, and corresponding tools are necessary. The Smart Grid Architecture Model (SGAM), an approach that has been developed during the last couple of years, provides a very good and structured basis for the design, development, and validation of new solutions and technologies. This review therefore provides a comprehensive overview of the state-of-the-art and related work for the theory, distribution, and use of the aforementioned architectural concept. The article itself provides an overview of the overall method and introduces the theoretical fundamentals behind this approach. Its usage is demonstrated in several European and national research and development projects. Finally, an outlook about future trends, potential adaptations, and extensions is provided as well.
Numerical Analysis of Transient Pressure Behaviors with Shale Gas MFHWs Interference
Authors: Gao Dapeng , Liu Yuewu , Wang Daigang , Han Guofeng
Published: January 2019

After the large-scale horizontal well pattern development in shale gas fields, the problem of fast pressure drop and gas well abandonment caused by well interference becomes more serious. It is urgent to understand the downhole transient pressure and flow characteristics of multi-stage fracturing horizontal well (MFHW) with interference. Therefore, the reservoir around the MFHW is divided into three regions: fracturing fracture, Stimulated reservoir volume (SRV), and unmodified matrix. Then, multi-region coupled flow model is established according to reservoir physical property and flow mechanism of each part. The model is numerically solved using the perpendicular bisection (PEBI) grids and the finite volume method. The accuracy of the model is verified by analyzing the measured pressure recovery data of one practical shale gas well and fitting the monitoring data of the later production pressure. Finally, this model is used to analyze the effects of factors, such as hydraulic fractures’ connectivity, well distance, the number of neighboring wells and well pattern arrangement, on the transient pressure and seepage characteristics of the well. The study shows that the pressure recovery double logarithmic curves fall in later part when the well is disturbed by a neighboring production well. The earlier and more severe the interference, the sooner the curve falls off and the larger the amplitude shows. If the well distance is closer, and if there are more neighboring wells and interconnected corresponding fracturing segments, the more severe interference appears among the wells. Moreover, the well interference may still exist even without interlinked fractures or SRV. Especially, severe interference will affect production when the hydraulic fractures are connected directly, and the interference is weaker when only SRV induced fracture network combined between wells, which is beneficial to production sometimes. When severe well interference occurs, periodic well shut-in is needed to help restore the reservoir pressure and output capacity. In the meanwhile, the daily output should be controlled reasonably to prolong the stable production time. This research will help to understand the impact of well interference to gas production, and to optimize the well spacing and achieve satisfied performance.
Flow and Fast Fourier Transform Analyses for Tip Clearance Effect in an Operating Kaplan Turbine
Authors: Kim Hyoung-Ho , Rakibuzzaman Md , Kim Kyungwuk , Suh Sang-Ho
Published: January 2019

The Kaplan turbine is an axial propeller-type turbine that can simultaneously control guide vanes and runner blades, thus allowing its application in a wide range of operations. Here, turbine tip clearance plays a crucial role in turbine design and operation as high tip clearance flow can lead to a change in the flow pattern, resulting in a loss of efficiency and finally the breakdown of hydro turbines. This research investigates tip clearance flow characteristics and undertakes a transient fast Fourier transform (FFT) analysis of a Kaplan turbine. In this study, the computational fluid dynamics method was used to investigate the Kaplan turbine performance with tip clearance gaps at different operating conditions. Numerical performance was verified with experimental results. In particular, a parametric study was carried out including the different geometrical parameters such as tip clearance between stationary and rotating chambers. In addition, an FFT analysis was performed by monitoring dynamic pressure fluctuation on the rotor. Here, increases in tip clearance were shown to occur with decreases in efficiency owing to unsteady flow. With this study’s focus on analyzing the flow of the tip clearance and its effect on turbine performance as well as hydraulic efficiency, it aims to improve the understanding on the flow field in a Kaplan turbine.
The Importance of Sensory Lexicons for Research and Development of Food Products
Authors: Suwonsichon Suntaree
Published: January 2019

A lexicon is a set of standardized vocabularies developed by highly trained panelists for describing a wide array of sensory attributes present in a product. A number of lexicons have been developed to document and describe sensory perception of a variety of food categories.The current review provides examples of recently developed sensory lexicons for fruits and vegetables; grains and nuts; beverages; bakery, dairy, soy and meat products; and foods for animals. Applications of sensory lexicons as an effective communication tool and a guidance tool for new product development processes, quality control, product improvement, measuring changes during product shelf life, and breeding new plant cultivars are also discussed and demonstrated through research in the field.
AMON Multimessenger Alerts: Past and Future
Authors: Ayala Solares Hugo
Published: January 2019

The Astrophysical Multimessenger Observatory Network (AMON) was founded to tie the world’s high-energy and multimessenger observatories into a single network, with the purpose to enable the discovering of multimessenger sources, to exploit these sources for purposes of astrophysics, fundamental physics, and cosmology, and to explore archival datasets for evidence of multimessenger source populations. Contributions of AMON to date include the GCN prompt alerts for likely-cosmic neutrinos, multiple follow-up campaigns for likely-cosmic neutrinos including the IceCube-170922A event, and several archival searches for transient and flaring γ + ν and ν + CR multimessenger sources. Given the new dawn of multimessenger astronomy recently realized with the detection of the neutron binary star merger and the possible γ + ν coincidence detection from the blazar TXS0506+056, in 2019, we are planning to commission several multimessenger alert streams, including GW + γ and high-energy γ + ν coincidence alerts. We will briefly summarize the current status of AMON and review our monitoring plans for high-energy and multimessenger AMON alerts during what promises to be a very exciting year for multimessenger astrophysics.