bluuebunny/crossref_metadata_2025 huggingface dataset:
Magnetotransport Properties of MnGeAs2 Films
Authors: Kim Yun Ki , Ketterson J.B.
Published: April 2017

MnGeAs2 thin films were successfully deposited on GaAs(100) substrate. The films exhibited room-temperature ferromagnetism with TC ~ 330 K, based on both magnetization and resistance measurements at temperatures from 5 to 370 K. The coercive fields at 5 and 300 K were 2100 and 50 Oe. The anomalous Hall effect was observed, suggesting the existence of spin polarized carriers in MnGeAs2 thin films. The magnetoresistance (MR) measurements showed very small change (~ 0.1% at 5 K) in resistance at low temperature. The MR value at 5 K was smaller than that (~ 9% at 305 K) at room temperature (305 K). Type of majority carriers in the films was determined to be n-type by Hall measurement above the transition temperature. The effective carrier density was 1.8´1020 cm-3. The diode current-voltage characteristics were shown in a hetero-junction MnGeAs2 film on a conducting p-type GaAs substrate.
Iron as a Promising Alloying Element for the Cost Reduction of Titanium Alloys: A Review
Authors: Abdalla Ayad Omran , Amrin Astuty , Muhammad Sallehuddin , Azmah Hanim Mohd Ariff
Published: April 2017

This article focuses on the effect of iron (Fe) addition on the fabrication of Ti-alloys. Fe is a potential inexpensive element that can be added to Ti-alloys to reduce their cost. This metal can also be used to replace expensive β-stabilizing alloying elements, such as vanadium (V) and molybdenum (Mo), for Ti-alloys. Fe has also been utilized as a novel cost-effective alloying element to decrease Ti-alloy costs and to design other alloys, such as Ti metal 62S (Ti-6Al-1.7Fe-0.1Si) and Ti-Fe-O-N Ti-alloy. This technical perspective has been further applied to fabricate new Ti-alloys. For example, Ti8LC and Ti-5.5Al-1Fe with good mechanical features have been developed as novel Ti-alloys in China and Japan, respectively. Nowadays, vanadium (V) of Ti-6Al-4V alloy is completely replaced with Fe to produce Ti-Al-Fe alloy series. Three new alloys, namely, Ti-6Al-xFe, where x = 1, 2, and 3 wt%, are introduced to examine the effect of Fe addition on the microstructure and mechanical properties of Ti-alloys.
Compute-Aided Design of Low Pressure Die-Casting Process of A356 Aluminum Wheels
Authors: Huang Pei Hsing , Wu Wei Jen , Shieh Chung Han
Published: April 2017

The lightweight design of aluminum automobile wheel can easily bring about all kinds of defects during die-casting, which often causes wheel frame deformation and creep damages in the future use and in turn affects traffic safety. To understand the evolution of mold flow, temperature field, and solidification, the low pressure die-casting processes of A356 aluminum wheel were simulated by Anycasting software package. Various casting parameters combined with the designs of flow channel and overflows were adopted to reduce the defects occurred in wheel products. In addition, we adopted the retained melt modulus (RMM) to predict the position of defects to be formed as well as their distribution so as to eliminate the shrinkage voids and porosity defects during die-casting. The research findings showed that the setting up of overflow tank could effectively prevent the formation of shrinkage void and porosity of die-castings and significantly promote the quality and productivity of die-casting wheel products.
Analysis of Overall Heat Transfer Coefficient of Composite Panels for Thermal Insulation
Authors: Jamiru Tamba , Adekomaya Oludaisi , Sadiku Rotimi , Huan Zhongie
Published: April 2017

Heat infiltration through the external wall of refrigerated vehicles has been a concern to food industries considering high thermal load required to sustain unbroken cold chain. In this research, experiments were carried out with known fibres contents laid out at various orientations and the effect on the heat transfer measured. The results indicate that the estimated overall heat transfer coefficient of the composite reinforced with 10%wt. of fibre at 0o orientation (G10E) offers the lowest U value of 0.386950 W/m2K and 0.196680 W/m2K for 50 mm and 100 mm insulation thicknesses respectively. The effect of fiber orientation in the composite panel in energy saving was to a large extent minimal when compared to the un-oriented composite panel
A Study on Automatic Sludge Discharger of a Water Tank of Intermediate Treatment Contractors of Construction Waste
Authors: Oh Gui Ho , Oh Sung Hoon
Published: April 2017

While an intermediate treatment contractor of construction waste extracts renewable fuels from construction wastes, water is stored in a water tank and a considerable amount of sludge remain in the water. In this respect, the present study designed an apparatus to automatically discharge sludge from the water tank. The discharging process of the apparatus is as follows: it sucks sludge along with water of the water tank into a storage tank. Sludge and water stay for a certain time period until the former settles. And water drains out from the storage tank, being separated from sludge that still remains in the storage tank. The amount of sludge to discharge depends on its storage time in the tank. Therefore, the duration of settlement was measured to find an optimal time. Discharging test was repeated. An impeller was installed on top of the storage tank to know how it affects sludge settlement. Using the collected data, this study confirmed the factors necessary for smooth discharging of sludge.
Ultrasonic Estimation of Volume Fraction of Kelvin Structure Using Micro-Structural Model
Authors: Kim Woo Chan Ethan , Yang Seung Yong , Kim Noh Yu
Published: April 2017

A quantitative ultrasound (QUS) method is developed for estimation of volume fraction of porous Kelvin structure to understand acoustic characteristics of trabecular bone. A Kelvin cellular specimen composed of isotropic tetra-kaidecahedron was produced by 3D printer with ABS plastic material to simulate artificial trabecular bone. The unit cell of Kelvin specimen has a size of 3.4mm and 81% of porosity. The specimen was completely filled with paraffin wax as a substitute of bone marrow. The speed of sound (SOS) of the wax-filled Kelvin specimen was measured using the time-of-flight (TOF) of ultrasound. Based on micro-structural model, shape parameters of Kelvin specimen is correlated with SOS and elastic constant to evaluate volume fraction of the specimen quantitatively. 25.8% of volume fraction was estimated for the Kelvin specimen which has actual volume fraction of 19%. It is concluded from experiment that the ultrasonic method developed in this study is effective and can be applied to diagnose and monitor osteoporosis.
Research on Location Method of PD Signal for Metal-Clad Switchgear
Authors: Wei Bin , Yu Guo Fu , Liu Fei , Sun Hao Jie , Li Hong Jie
Published: April 2017

It is well known that the occurrence of partial discharge phenomena within switchgears can lead to their destruction. Early detection can avoid failures of electrical equipment. The work of this paper mainly provides theoretic foundation for precise partial discharge (PD) location in switchgears. Hyperboloid method and spatial grid search method are proposed to locate PD source with transient earth voltage (TEV) test. Finite-difference time-domain (FDTD) is used to simulate the propagation process of TEV signal and validate the proposed method. Laboratory test on operating switchgear was conducted and the test results were in consistent with the simulation.
XPS Studies of the Graded Band Gap AlxGa1-xN Material Grown by MOCVD
Authors: Fu Xiao Qian , Li Yang , Li Zhi Ming , Zhang Chun Wei , Wang Xiao Hui
Published: April 2017

To characterize the properties of the as-grown AlxGa1-xN material for producing high property AlxGa1-xN photocathode in ultraviolet (UV) detection, the Ar+ sputtering and X-ray photoelectric spectroscopy (XPS) scan are performed. XPS spectra indicates that although processed with chemical solutions, AlxGa1-xN still contains large amount of carbon and oxide on the surface, which can be completely removed by Ar+ sputtering within few minutes. Ga3d and Al2p curves show that there are other compounds of Ga and Al on the surface but both become very concentrated when sputtering continues. The proportion of Al increases and that of Ga decreases gradually from surface to AlN bulk, which testify the graded band gap profile of the AlxGa1-xN sample. There is always a very slight amount of oxygen in the AlN layer, which is regarded as native element during material growth. At the interface of AlN and sapphire, an abrupt transition appears which can influence the properties of the AlxGa1-xN photocathode when it works with the transmittance mode
High-Temperature Corrosion of Incoloy Alloy 800 in N2/H2S Gas
Authors: Kim Min Jung , Lee Dong Bok
Published: April 2017

The nickel-iron-chromium-based alloy, Incoloy alloy 800, was corroded at 600, 700 and 800 °C for 10-70 h under 1 atm of total pressure in three different atmospheres, viz., 1 atm of N2, N2/H2O, and N2/H2O/H2S-mixed gases. The corrosion rates always increased with addition of H2O and, much more seriously, with the addition of H2S gas. In N2 and N2/H2O gases, oxidation prevailed. In N2/H2O/H2S gases, sulfidation dominated. The corrosion resistance increased in the T22 steel displayed better resistance to oxidation and sulfidation than Fe-2Mn-0.5Si steel, owing to the presence of Cr. Strong enrichment of Cr and the presence of Ni and Fe were noticeable in the inner scale. Chromium sulfidized to FeCr2S4 in N2/H2O/H2S gases, which was responsible for the enhanced sulfidation resistance of T22 compared with Fe-2.0Mn-0.5Si steel.
Half Metallic Behavior in H-Terminated Zigzag BC2N Nanoribbons
Authors: Xiao Xiang , Li Hong , Tie Jun , Lu Jing
Published: April 2017

We study structural, stability, electronic and magnetic properties of zigzag-edged BC2N nanoribbons (ZBC2NNRs) with H-termination in the view of first principles calculations. Four kinds of edge arrangements are considered, labeled as B-C, N-C, N-B, and C-C. Interestingly, we find these four types of H-terminated ZBC2NNRs have various electronic structures. The half-metal and semi-metal are obtained depending on the edge atom alignment. The B-C and N-C ZBC2NNRs with H-termination are half-metals with antiferromagnetic (AFM) ground states. The magnetic moments of the antiferromagnetic (AFM) state always prefer to locate at the ribbon edges. However, the N-B and C-C ZBC2NNRs show spin-unpolarized semi-metallic behaviors at ground states. Our results suggest that the H-terminated ZBC2NNRs can be a promising candidate material in nanoelectronics and nanospintronics.
Measurement Uncertainty Calculation of the Shear Stress in the Shear Tests
Authors: Mantilla J.N.R. , Smits M.A. , Pizzol V.D. , Krüger P.V. , Rezende M.A.P. , Alves R.C. , Carrasco E.V.M.
Published: April 2017

The objective of this paper is to present a methodology for the measurement of the uncertainty in the calculation result in the shear strength test. Is intended with this work is to gather subsidies to justify the adoption of the measurement of the uncertainty in calculation procedure as a regulatory requirement and part of the report of wood characterization tests. The motivation for submitting this proposal is due to the difficulty in reaching some technical requirements specified by the rules, especially the requirement on "quality assurance testing and calibration results". The proposed methodology consolidates the procedures necessary to obtain the individual measurement uncertainty of the failure stress and the mean result of the uncertainty of failure stress. This methodology meets the requirements of a quality management system. The uncertainty values of the individual results of failure stress were negligible indicating a high-quality equipment and good calibration of them. The uncertainty of the measurement of the mean failure stress was considerable, indicating the importance of their consideration in the safety of wooden structures.
Experimental Validation of Splitting Tensile Strength of Self Consolidating Concrete
Authors: Mohamed Osama Ahmed , Najm Omar Fawwaz
Published: April 2017

The American Concrete Institute (ACI) code of concrete design ACI 318, and many other concrete codes report expressions for estimating splitting tensile strength as a function of the specified concrete compressive strength. However, for self-consolidating concreate, research is still needed to develop reliable expressions for the prediction of splitting tensile strength. Mohamed et al. [1] proposed an expression for splitting tensile strength of sustainable self-consolidating concrete in which cement was partially replaced with fly Ash, silica fume, and ground granulated blast furnace slag (GGBS). This paper presents validation of the splitting tensile strength expression using additional test data in which concrete mixes were prepared using various water/cement ratios. expression developed by Mohamed et. al. [1] exhibits excellent correlation with test data as demonstrated in this paper.
Influences of Scarf-Joint of the Laminae in the Strength and Elasticity of Glued Laminated Timber Beams
Authors: Carrasco E.V.M. , Mantilla J.N.R. , Smits M.A. , Pizzol V.D. , Krüger P.V. , Rezende M.A.P. , Alves R.C.
Published: April 2017

The objective of this work is to determinate the influence of the scarf-jointed in the strength and the modulus of elasticity of the glued laminated timber beam. To determine this influence, several tests with the outer laminae with scarf-joint and the bevel with different inclinations has been made. The models were made of Parana Pine, Araucaria angustifolia. For the tests were performed three points bending. With the load values and the deflection at mid-span and by linear regression were determined the effective elastic modulus. The results indicate that the performance is reduced considerably in the presence of a scarf-joint in the external laminae and also the reduction is greater when the scarf angle increases.
Prediction of Soil Creep Deformation Using Unequal Interval Multivariable Grey Model
Authors: Zhi Qing , Song Jing Ran , Guo Zheng Xing
Published: April 2017

Arch bridges will produce horizontal internal force at arch springing under vertical load. The horizontal internal forces and displacement of abutments have significant influences on structural behavior of arch bridge, which was located at soft soil foundation. One of the effective methods to solve the problem is applied the pre-pushing technique behind abutment by two horizontal anti-slide slab. However, there is soil creep deformation at the arch springing under the long-term vertical load. Therefore, an unequal interval multivariable grey model was established to predict the soil creep deformation. This grey model was extended by a single point and equal interval model. The modeling steps are also proposed in this paper. And then the calculated results by the proposed model will compared with the measured results and the results of Burgers model. The compared results showed that it can precisely and effectively predict the amplitude of the creep deformations.
A Study of Adobes Made with No Usual Soils Concerning Grain Size Distribution Test
Authors: Rezende M.A.P. , Alves R.C. , Carrasco E.V.M. , Mantilla J.N.R. , Smits M.A. , Pizzol V.D. , Krüger P.V.
Published: April 2017

This article presents and discusses an adobe production with shows a clay/silt/sand proportion that is completely different from that recommended by most authors and construction associations. The main objective was to improve comprehension of earth behaviors as building material by studying these two atypical cases of adobe production. The soil was analyzed by different tests as the grain size distribution test and Atterberg limits. Adobe resistance was tested using a methodology proposed by Proterra network which was created by a group of researchers from different Iberian American laboratories. This methodology was used in Ph.D. thesis, too. The results show a soil with 1% clay and 65.1 silte and an average of resistance of 2.11 MPa for the adobes. These results show the importance of the clay mineral structure and the complexity of the soil behavior, indicating the need for additional studies.
Structural Features of the Carbon Material Synthesized by Plasma-Arc Method at Low Buffer Gas Pressure
Authors: Zaikovskii Alexey V.
Published: April 2017

The carbon material was synthesized by the plasma-arc method at the buffer gas pressure of 3 Torr. The material has physical properties different from the properties of the material synthesized at pressure of 25 Torr and higher. The low pressure of buffer gas leads to formation of materials consisting of carbon nanoparticles with average size lower than 10nm. The nanoparticles have form of carbon globules, which consist of the graphite-like structure. This structure is the composition of the stacked, twisted and closed nanofragments of graphene. The dominating interlayer distance in the structure is 0.4 nm. The dominating size of crystallinity La is 2.7nm. The graphite-like structure allows to enhance the electrical conductivity in compare with the material synthesized at buffer gas pressure of 25 Torr and higher. Nevertheless the conductivity of the material is significantly lower than the conductivity of pure graphite because of the contact resistance arising from the presence of the outer layer of amorphous carbon on some globules and the presence of the globules of fully amorphous carbon.
Construction Scope: Quality, Budget and Timeline ‘Small’ Endeavours, Portuguese Context
Authors: Cortiços Nuno Dinis Costa Areias
Published: April 2017

The trinomial of the scope, quality, budget and timeline, is an objective by excellence, pursued by those with an active role in the production process, to which the construction sector is no stranger. The ideal is to ensure the satisfaction of the three parameters/variables, by those who seek construction services: Project Owner. Why the Scope is not reached! The causes are divided in two levels: insufficient training, rooted in the Sector, that favours informality; and, lack of data to understand the causes, resulting in no definition or application of corrective measures (good practices guides). The focus of this article is the 'small endeavours', managed by: (1) Real Estate Developer, in control of the different phases, from municipal licensing, through the project and construction license, the remaining will be undertaken by a Builder or Investor, for subsequent sale; or (future) Owner without control of the initial decisions; the concerns of the latter are bound by the binomial Timeline and Budget; or, (2) P.O., from the outset, take control of all phases, always faithful to his idea of the Scope; introduces adjustments and changes defending his point of view or interest without the perception of the real impact of those on the overall satisfaction, focused on the fulfilment of quality achieved.
Precursor Derived Ceramic Method to Fabricate SiC Ceramic Composite Coatings on Metallic Substrates
Authors: Guo Wei Ling , Li En Zhong , Yang Da Xiang
Published: April 2017

In this paper, the polymer precursor derived ceramic (PDC) method, that was used to fabricate the silicon carbide (SiC) ceramic composite coatings on metallic substrates, was briefly summarized. Two different fabrication mechanism of ceramic coatings by PDC method were mainly introduced. One was that Al powder as the active fillers converted into AlN due to the action with N2. The other was that Al powder as the active fillers converted into Al2O3 due to the action with O2. So fabrication mechanism of ceramic coatings by PDC method would be still the research focus in the future. Compared with the other methods, the advantages and disadvantages of PDC method preparing ceramic coatings were displayed. According to the existent problems and future development direction of PDC method, the key research objectives were presented.
Lis1 Regulates Germinal Center B Cell Antigen Acquisition and Affinity Maturation
Authors: Chen Jingjing , Cai Zhenming , Zhang Le , Yin Yuye , Chen Xufeng , Chen Chao , Zhang Yang , Zhai Sulan , Long Xuehui , Liu Xiaolong , Wang Xiaoming
Published: April 2017

The germinal center (GC) is the site where activated B cells undergo rapid expansions, somatic hypermutation, and affinity maturation. Affinity maturation is a process of Ag-driven selection. The amount of Ag acquired and displayed by GC B cells determines whether it can be positively selected, and therefore Ag acquisition has to be tightly regulated to ensure the efficient affinity maturation. Cell expansion provides sufficient quantity of GC B cells and Abs, whereas affinity maturation improves the quality of Abs. In this study, we found that Lis1 is a cell-intrinsic regulator of Ag acquisition capability of GC B cells. Lack of Lis1 resulted in redistribution of polymerized actin and accumulation of F-actin at uropod; larger amounts of Ags were acquired and displayed by GC B cells, which presumably reduced the selection stringency. Affinity maturation was thus compromised in Lis1-deficient mice. Consistently, overexpression of Lis1 in GC B cells led to less Ag acquisition and display. Additionally, Lis1 is required for GC B cell expansion, and Lis1 deficiency blocked the cell cycle at the mitotic phase and GC B cells were prone to apoptosis. Overall, we suggest that Lis1 is required for GC B cell expansion, affinity maturation, and maintaining functional intact GC response, thus ensuring both the quantity and quality of Ab response.
Problems and Solutions in US Refugee Resettlement Policy: An Interview with Liyam Eloul
Authors: Kanof Marisa
Published: April 2017

Liyam Eloul is a trauma therapist specialized in the field of refugee mental health. She received her BA in Cultural Psychology from Queen’s University, Ontario, a graduate diploma in Psychosocial Interventions for Refugees and Forced Migrants at the American University in Cairo, and her MA in International Disaster Psychology from the University of Denver. Eloul has worked with resettled refugee populations in the United States and refugee populations in Egypt, Afghanistan, Syria, Oman, and Jordan. She received a Fulbright Award for cross-cultural trauma research in Oman, and has published on mental health and psychosocial programming in the United States, Oman, and Syria. Currently, Eloul is a Psychotherapist Trainer with the Center for Victims of Torture in Amman, Jordan.
Access to curriculum for students with disabilities at higher education institutions: How does the National University of Lesotho fare?
Authors: Mosia Paseka A. , Phasha Nareadi
Published: April 2017

Background: Creating access to curricula at institutions of higher education for students with disabilities requires a concerted effort from management and other key stakeholders to identify students’ needs and create opportunities for success.Objectives: This paper presents the findings of a study which examined students with disabilities’ access to curricula at a higher education institution in Lesotho.Method: Data for this qualitative study were collected using three methods: in-depth interviews, focus group discussions and document analysis. Eleven students with various types of impairments and 15 academic and non-academic staff members currently working in close proximity to students with disabilities participated in this study.Results: The findings reveal inconsistencies between the institution’s admission policy of non-discrimination according to disability status and its practices. These inconsistencies are discussed under the following themes: (1) access at admission level, (2) management of disability data, (3) support by the special education unit, (4) teaching strategies, (5) support by lecturers, (6) availability of assistive technology, (7) special concessions and (8) students’ coping mechanisms.Conclusion: We recommend that a clear policy concerning the support of students with disabilities be developed with the following aims: guide decisions on how disability data should be used, define roles that different university departments must play in facilitating access to curricula for all students, influence suitable development of teaching and learning resources, stimulate research on success and completion rates of students with disabilities and mandate restructuring of programmes that are currently inaccessible to students with disabilities. Key stakeholders, including students with disabilities, disabled persons’ organisations, disability rights activists, and staff should be involved in such policy design.
Pulmonary agenesis, pulmonary aplasia and pulmonary hypoplasia: Can you differentiate them?
Authors: Verwey Charl , Van der Merwe Cornelis , Pillay Tanyia
Published: April 2017

No abstract available.
Cytomorphologic features distinguishing Bethesda category IV thyroid lesions from parathyroid
Authors: Sung Simon , Saqi Anjali , Margolskee Elizabeth M. , Crapanzano John P.
Published: April 2017

Background:

Thyroid follicular cells share similar cytomorphological features with parathyroid. Without a clinical suspicion, the distinction between a thyroid neoplasm and an intrathyroidal parathyroid can be challenging. The aim of this study was to assess the distinguishing cytomorphological features of parathyroid (including intrathyroidal) and Bethesda category IV (Beth-IV) thyroid follicular lesions, which carry a 15%–30% risk of malignancy and are often followed up with surgical resection.

Methods:

A search was performed to identify “parathyroid” diagnoses in parathyroid/thyroid-designated fine-needle aspirations (FNAs) and Beth-IV thyroid FNAs (follicular and Hurthle cell), all with diagnostic confirmation through surgical pathology, immunocytochemical stains, Afirma® analysis, and/or clinical correlation. Unique cytomorphologic features were scored (0-3) or noted as present versus absent. Statistical analysis was performed using R 3.3.1 software.

Results:

We identified five FNA cases with clinical suspicion of parathyroid neoplasm, hyperthyroidism, or thyroid lesion that had an eventual final diagnosis of the parathyroid lesion (all female; age 20–69 years) and 12 Beth-IV diagnoses (11 female, 1 male; age 13–64 years). The following cytomorphologic features are useful distinguishing features (P value): overall pattern (0.001), single cells (0.001), cell size compared to red blood cell (0.01), nuclear irregularity (0.001), presence of nucleoli (0.001), nuclear-to-cytoplasmic ratio (0.007), and nuclear chromatin quality (0.028).

Conclusions:

There are cytomorphologic features that distinguish Beth-IV thyroid lesions and (intrathyroidal) parathyroid. These features can aid in rendering correct diagnoses and appropriate management.
On the universal CH$_ 0$ group of cubic hypersurfaces
Authors: Voisin Claire
Published: April 2017

We study the existence of a Chow-theoretic decomposition of the diagonal of a smooth cubic hypersurface, or equivalently, the universal triviality of its CH

_0

group. We prove that for odd-dimensional cubic hypersurfaces or for cubic fourfolds, this is equivalent to the existence of a cohomological decomposition of the diagonal, and we translate geometrically this last condition. For cubic threefolds

X

, this turns out to be equivalent to the algebraicity of the minimal class

\theta^4/4!

of the intermediate Jacobian

J(X)

. In dimension 4, we show that a special cubic fourfold with discriminant not divisible by 4 has universally trivial CH

_0

group.
Rigidity of smooth critical circle maps
Authors: Guarino Pablo , de Melo Welington
Published: April 2017

We prove that any two

C^3

critical circle maps with the same irrational rotation number of bounded type and the same odd criticality are conjugate to each other by a

C^{1+\alpha}

circle diffeomorphism, for some universal

\alpha>0

.
О средней длине конечных цепных дробей с фиксированным знаменателем
Authors: Bykovskii Victor Alexeevich , Frolenkov Dmitry Andreevich
Published: April 2017

В 1968 г. Х. Хейльбронн доказал асимптотическую формулу для среднего значения длин разложений в непрерывную дробь рациональных чисел с одинаковыми знаменателями. В работе предложен новый метод решения задачи Хейльбронна и ее обобщений. Получены новые оценки остаточных членов, улучшающие предшествующие результаты Дж. Портера (1975 г.) и А. В. Устинова (2005 г.).
Библиография: 28 названий.
Релаксация и управляемость в задачах оптимального управления
Authors: Avakov Evgeny Rachievich , Magaril-Il'yaev Georgii Georgievich
Published: April 2017

Исследуются взаимосвязи необходимых условий минимума в абстрактной задаче оптимального управления, условий минимума в соответствующей релаксационной (ослабленной) задаче и достаточных условий локальной управляемости управляемой системы. Полученные результаты применяются к задаче оптимального управления достаточно общего вида.
Библиография: 7 названий.
Связь вида нормы и геометрии минимальных сетей
Authors: Laut Il'ya Leonidovich
Published: April 2017

Исследуется задача, обратная задаче поиска минимальных сетей Штейнера в нормированных пространствах. А именно, пусть дано нормированное пространство, в котором для каждого конечного множества точек известны все кратчайшие сети. Требуется описать все нормы, для которых кратчайшие сети такие же, как в данном нормированном пространстве. В работе приводятся краткий обзор известных результатов и доказательство уникальности набора минимальных сетей Штейнера для каждого двумерного нормированного пространства со строго выпуклой дифференцируемой нормой. Кроме того, получены доказательства непрерывности координат подвижных вершин и определено направление поворота невырожденной минимальной параметрической сети при малых деформациях граничного множества в двумерном пространстве со строго выпуклой дифференцируемой нормой.
Библиография: 15 названий.
О классах Бэра ляпуновских инвариантов
Authors: Bykov Vladimir Vladislavovich
Published: April 2017

Показано отсутствие связи (кроме естественной) между классами Бэра инвариантов преобразований Ляпунова в компактно-открытой и равномерной топологиях на пространстве линейных дифференциальных систем.
Установлено, что в представлении функционала на пространстве систем с компактно-открытой топологией в виде повторного предела от кратной последовательности непрерывных функционалов последние можно выбрать так, чтобы они определялись значениями коэффициентов системы на конечном отрезке полуоси (своем для каждого функционала).
Доказано, что показатели Ляпунова нельзя представить как предел от последовательности (не обязательно непрерывных) функционалов, каждый из которых зависит только от сужения системы на конечный отрезок полуоси.
Библиография: 28 названий.
The Roles of Ti Particles in Improving the Corrosion Resistance of Electrochemically Assembled Ni-Ti Composite Coatings
Authors: Zhao Yuantao , Wang Lianbo , Qin Zhenbo , Wang Chengxi , Xu Zhou , Jiang Chuanhai , Ji Vincent
Published: April 2017

The influences of co-deposited Ti particles on corrosion behavior of electrodeposited Ni-Ti coatings were investigated. The co-deposited Ti particles caused the refined crystallite size and random-oriented texture of Ni-Ti coating. In 3.5 wt% sodium chloride (NaCl) solution, the buried Ti particles in Ni matrix blocked the corrosion path and rapid intercrystalline corrosion. The inert TiO2 could form on the exposed Ti particles and hinder localized corrosion. In 10 wt% sodium hydroxide (NaOH) solution, Ni matrix crystallites, refined by co-deposited Ti particles, contributed to formation of the passive Ni(OH)2 film. The corrosion current of Ni-Ti coating decreased by about one order of magnitude in both solutions with respect to pure Ni coating, demonstrating the co-deposited Ti particles greatly improved the corrosion resistance of Ni-Ti composite coatings. Finally, a corrosion mechanism was built to explain the co-deposited Ti particles improved corrosion resistance of the Ni-Ti composite coatings.
The Environmental Documentary
Authors: Duvall John A.
Published: April 2017

The Environmental Documentary provides the first extensive coverage of the most important environmental films of the decade, including their approach to their topics and their impacts on public opinion and political debate. While documentaries with themes of environmental activism date back at least to Pare Lorenz's films of the 1930s, no previous decade has produced the number and quality of films that engage environmental issues from an activist viewpoint. The convergence of high profile issues like climate change, fossil fuel depletion, animal abuse, and corporate malfeasance has combined with the miniaturization of high quality recording equipment and the expansion of documentary programming to produce an unprecedented number of important and influential documentary productions.

The text examines the processes of production and distribution that have produced this explosion in documentaries. The films range from a high-profile Hollywood production with theatrical distribution like An Inconvenient Truth, to shorter independently produced films like The End of Suburbia that have reached a small audience of activists through video distribution, interviews with many of the filmmakers, and word of mouth.
Lower-tropospheric CO2 from near-infrared ACOS-GOSAT observations
Authors: Kulawik Susan S. , O'Dell Chris , Payne Vivienne H. , Kuai Le , Worden Helen M. , Biraud Sebastien C. , Sweeney Colm , Stephens Britton , Iraci Laura T. , Yates Emma L. , Tanaka Tomoaki
Published: April 2017

Abstract. We present two new products from near-infrared Greenhouse Gases Observing Satellite (GOSAT) observations: lowermost tropospheric (LMT, from 0 to 2.5 km) and upper tropospheric–stratospheric (U, above 2.5 km) carbon dioxide partial column mixing ratios. We compare these new products to aircraft profiles and remote surface flask measurements and find that the seasonal and year-to-year variations in the new partial column mixing ratios significantly improve upon the Atmospheric CO2 Observations from Space (ACOS) and GOSAT (ACOS-GOSAT) initial guess and/or a priori, with distinct patterns in the LMT and U seasonal cycles that match validation data. For land monthly averages, we find errors of 1.9, 0.7, and 0.8 ppm for retrieved GOSAT LMT, U, and XCO2; for ocean monthly averages, we find errors of 0.7, 0.5, and 0.5 ppm for retrieved GOSAT LMT, U, and XCO2. In the southern hemispheric biomass burning season, the new partial columns show similar patterns to MODIS fire maps and MOPITT multispectral CO for both vertical levels, despite a flat ACOS-GOSAT prior, and a CO–CO2 emission factor comparable to published values. The difference of LMT and U, useful for evaluation of model transport error, has also been validated with a monthly average error of 0.8 (1.4) ppm for ocean (land). LMT is more locally influenced than U, meaning that local fluxes can now be better separated from CO2 transported from far away.
The ion trap aerosol mass spectrometer: field intercomparison with the ToF-AMS and the capability of differentiating organic compound classes via MS-MS
Authors: Fachinger Johannes R. W. , Gallavardin Stéphane J. , Helleis Frank , Fachinger Friederike , Drewnick Frank , Borrmann Stephan
Published: April 2017

Abstract. Further development and optimisation of a previously described ion trap aerosol mass spectrometer (IT-AMS) are presented, which resulted in more reproducible and robust operation and allowed for the instrument's first field deployment. Results from this 11-day-long measurement indicate that the instrument is capable of providing quantitative information on organics, nitrate, and sulfate mass concentrations with reasonable detection limits (0.5–1.4 µg m−3 for 1 h averages) and that results obtained with the IT-AMS can directly be related to those from Aerodyne aerosol mass spectrometers. The capability of the IT-AMS to elucidate the structure of fragment ions is demonstrated via an MS4 study on tryptophan. Detection limits are demonstrated to be sufficiently low to allow for MS2 studies not only in laboratory but also in field measurements under favourable conditions or with the use of an aerosol concentrator. In laboratory studies the capability of the IT-AMS to differentiate [C4Hy]+ and [C3HyO]+ fragments at the nominal m∕z 55 and 57 via their characteristic fragmentation patterns in MS2 experiments is demonstrated. Furthermore, with the IT-AMS it is possible to distinguish between fragments of the same elemental composition ([C2H4O2]+ at m∕z 60 and [C3H5O2]+ at m∕z 73) originating from different compound classes (carboxylic acids and sugars) due to their different molecular structure. These findings constitute a proof of concept and could provide a new means of distinguishing between these two compound classes in ambient organic aerosol.
Sandpile-based model for capturing magnitude distributions and spatiotemporal clustering and separation in regional earthquakes
Authors: Batac Rene C. , Paguirigan Jr. Antonino A. , Tarun Anjali B. , Longjas Anthony G.
Published: April 2017

Abstract. We propose a cellular automata model for earthquake occurrences patterned after the sandpile model of self-organized criticality (SOC). By incorporating a single parameter describing the probability to target the most susceptible site, the model successfully reproduces the statistical signatures of seismicity. The energy distributions closely follow power-law probability density functions (PDFs) with a scaling exponent of around −1. 6, consistent with the expectations of the Gutenberg–Richter (GR) law, for a wide range of the targeted triggering probability values. Additionally, for targeted triggering probabilities within the range 0.004–0.007, we observe spatiotemporal distributions that show bimodal behavior, which is not observed previously for the original sandpile. For this critical range of values for the probability, model statistics show remarkable comparison with long-period empirical data from earthquakes from different seismogenic regions. The proposed model has key advantages, the foremost of which is the fact that it simultaneously captures the energy, space, and time statistics of earthquakes by just introducing a single parameter, while introducing minimal parameters in the simple rules of the sandpile. We believe that the critical targeting probability parameterizes the memory that is inherently present in earthquake-generating regions.
A EDUCAÇÃO FÍSICA NO ENSINO MÉDIO INTEGRADO A EDUCAÇÃO PROFISSIONAL E TECNOLÓGICA: PERCEPÇÕES, CURRICULARES
Authors: Boscatto Juliano Daniel , Darido Suraya Cristina
Published: April 2017

O objetivo desse estudo foi identificar como os professores entendem ser a finalidade da EF e quais são os conteúdos de ensino predominantes para o ensino médio integrado a educação profissional em um Instituto Federal localizado no estado de Santa Catarina. A amostra constituiu-se de seis professores de Educação Física de diferentes regiões do estado catarinense. A coleta de dados envolveu análise documental e entrevistas semiestruturadas. A finalidade da Educação Física resume-se em: promoção de saúde; compreensão crítica dos conteúdos de ensino. Os conteúdos de ensino predominantes podem ser classificados em três blocos: práticas corporais relacionadas à saúde, esportes e componentes da cultura corporal
OS TESTES DE APTIDÃO FÍSICA NA EDUCAÇÃO FÍSICA: DA JUSTIÇA COMO EQUIDADE AO DIREITO À EDUCAÇÃO
Authors: Baptista Guilherme Gonçalves , Baptista Juliana Gonçalves
Published: April 2017

É justo limitar a entrada de alunos em cursos de Educação Física devido ao insucesso nos testes físicos? O presente ensaio apresenta reflexões iniciais sobre a legitimidade e as limitações da exigência dos testes de habilidade específica para o ingresso discente nos cursos superiores em Educação Física, trazendo à baila questões sobre justiça e direito à educação. A partir da teoria de justiça rawlsiana, os testes foram mobilizados para problematizar as condições mínimas necessárias para ingresso discente e as próprias identidades profissionais em torno da Educação Física. Notou-se que a exigência de competências mínimas colidia com o processo plural de construção identitária da área e servia, de certo modo, como um limitador da própria condição humana: o direito à educação.
PRÁTICA PEDAGÓGICA DO PROFESSOR DE EDUCAÇÃO FÍSICA NA ESCOLA: DIFICULDADES PERCEBIDAS POR UMA EQUIPE ESCOLAR NA CIDADE DE SÃO PAULO
Authors: Maldonado Daniel Teixeira , Pereira dos Santos Silva Sheila Aparecida
Published: April 2017

O objetivo desse estudo foi identificar e compreender os fatores que dificultam a implementação dos currículos de Educação Física por meio uma pesquisa descritiva de cunho qualitativo, realizada em uma escola municipal da zona leste da cidade de São Paulo. Os principais fatores encontrados foram: descontentamento profissional, jornada de trabalho extensa, baixa remuneração, formação profissional insuficiente e desorganização do trabalho nessa rede. Concluímos que os fatores encontrados se relacionam a diferentes aspectos presentes nas dimensões Institucional/Organizacional e Sociopolítica/Cultural e que, portanto, o professor não é o único responsável pelos possíveis descompassos entre o que é proposto oficialmente pelos órgãos centrais e o que é implementado na escola.
Language Practitioners’ Reflections on Method-based and Post-method Pedagogies
Authors: Soomro Abdul Fattah , Almalki Mansoor S.
Published: April 2017

Method-based pedagogies are commonly applied in teaching English as a foreign language all over the world. However, in the last quarter of the 20th century, the concept of such pedagogies based on the application of a single best method in EFL started to be viewed with concerns by some scholars. In response to the growing concern against the concept of a method, some scholars started to offer alternatives to a method in different forms. Kumaravadivelu is one of the scholars who offers his post-method macro-strategic framework as an alternative to method-based pedagogies. This small-scale study explores English language practitioners’ experience and their views about applying method-based and post-method pedagogies. Semi-structured pre- and post-interviews were conducted from eight participants. The pre-interviews investigated the teacher-participants’ views about the method-based pedagogies in practice and the post-interviews aimed at knowing the prospects and concerns in the application of post-method pedagogies in their context. Although participants were skeptical of the concept of methods, they considered them useful in making contribution towards learning and teaching English. They found post-method pedagogies as more preferable option to method-based pedagogies in ELT on the ground; the post-method pedagogies, according to them, give broad directions while specific methods make teachers to work within narrow guidelines. However, they showed certain concerns in the application of such pedagogies in their context.
Porównywalność w czasie informacji o wynikach działalności społecznie odpowiedzialnej firm raportujących według zasad GRI
Authors: Waniak-Michalak Halina
Published: April 2017

Porównywalność w czasie informacji o wynikach działalności społecznie odpowiedzialnej firm raportujących według zasad GRI

The involvement of corporations in corporate social responsibility (CSR) activities with respect for work- ers' rights and ethical principles brings tangible benefits to the enterprise. CSR activities can therefore be considered as an investment, the effects of which should be measured. CSR benefits derive from im- proved assessment of the corporation by the stakeholders and increased social trust. However, in order to achieve the desired results of CSR activities, it is necessary to provide adequate information to customers, employees and owners. Moreover, the measurement of CSR results is necessary to determine the effec- tiveness of the actions taken. The aim of the article was to answer the question if companies present the same measures in successive CSR reports and whether it is possible to compare the CSR activity results for successive years. Examination of 31 CSR reports for two consecutive editions of the reporting showed that companies change the number and type of disclosed measures.
Fine-Needle Aspiration Versus Frozen Section in the Evaluation of Malignant Thyroid Nodules in Patients With the Diagnosis of Suspicious for Malignancy or Malignancy by Fine-Needle Aspiration
Authors: Ye Qin , Woo Jennifer S. , Zhao Qunzi , Wang Ping , Huang Pintong , Chen Lirong , Li Xin , Xu Kanlun , Yong Ying , (Sung-Eun) Yang Stephanie , Rao Jianyu
Published: April 2017

Context.—

The Bethesda System for Reporting Thyroid Cytopathology recommends against the use of intraoperative frozen section (FS) during lobectomy of a thyroid nodule with a fine-needle aspiration (FNA) diagnosis of malignant. Bethesda recommendations for FS in the FNA category of suspicious for malignancy (SFM) is less well-defined. In some institutions in China, FS examination is performed during lobectomy even for FNA-proven malignant cases.

Objective.—

—To compare the efficacy of FNA versus FS in the evaluation of malignant thyroid lesions.

Design.—

A 3-year retrospective analysis from a single institution was performed on cases with an FNA diagnosis of SFM or malignant with subsequent FS examination during thyroidectomy. The results of FNA and FS findings were compared to the final thyroidectomy pathology.

Results.—

—A total of 5832 thyroidectomy procedures were performed: 1265 cases had FNA and FS results available. Fine-needle aspiration gave a diagnosis of SFM to 306 cases and a diagnosis of malignant to 821 cases. Of the SFM cases, 10.5% (32 of 306) had benign/indeterminate, 4.6% (14 of 306) suspicious, and 84.9% (260 of 306) malignant FS results. Final pathology showed 56.3% (18 of 32), 64.3% (9 of 14), and 100% (260 of 260) malignancy rates, respectively. For the malignant FNA group, 10.0% (82 of 821) had benign/indeterminate, 4.4% (36 of 821) suspicious, and 85.6% (703 of 821) malignant FS results. The final pathology showed 96.4% (79 of 82), 97.2% (35 of 36), and 99.9% (702 of 703) malignancy rates, respectively.

Conclusions.—

Frozen section should not be performed for the malignant FNA category because FS evaluation may result in 10% falsely negative findings. Performing FS for SFM may be better justified; however, more than half of FS cases read as benign in this category had malignant final pathology. Therefore, caution should be taken for FS results even in the SFM group.
Quand les Casques bleus passent au vert
Authors: Maertens Lucile
Published: April 2017

À partir d’une enquête menée au sein des Départements des opérations de maintien de la paix et de l’appui aux missions de l’onu, cet article met en évidence un processus d’environnementalisation des opérations de maintien de la paix. Il procède d’une dynamique bottom-up s’inscrivant dans les préoccupations environnementales croissantes qui se développent sur le terrain et d’une logique top-down en se matérialisant par la mise en place, au secrétariat, d’une politique environnementale pour l’ensemble des missions. En dépit d’une mise en oeuvre inégale et d’un verdissement limité, l’appropriation de l’environnement par les Casques bleus répond à des objectifs stratégiques de mise à l’agenda de l’environnement auprès des acteurs sécuritaires et de rapprochement entre environnement et sécurité à l’onu.
Responsabilité environnementale des entreprises et régulation extraterritoriale
Authors: Bommier Swann
Published: April 2017

Dans une économie globalisée, promouvoir la responsabilité environnementale des entreprises est un défi majeur. Des organisations internationales ont peu à peu établi des cadres normatifs et des instances de régulation pour rendre les entreprises redevables de leurs impacts environnementaux devant des audiences transnationales. Durant deux ans, nous avons étudié l’instance de régulation mise en place par l’ocdedans le cadre de ses principes directeurs à l’intention des multinationales. Nous démontrons ici que cette instance ne répond que partiellement aux enjeux environnementaux contemporains : son architecture institutionnelle compromet son indépendance, tandis que son mandat extraterritorial ne parvient pas à envisager les enjeux environnementaux dans leur globalité.