bluuebunny/crossref_metadata_2025 huggingface dataset:
The Application Research of Amplitude Spectrum in the Coating Layer Thickness Detection
Authors: Zhang Ji Tang , Peng Bin Bin
Published: May 2011

The caoting layer of each industry structure detected by ultrasonic testing is one commonly used thickness detection technique. This article proposed a method which used the extreme value of resonant amplitude spectrum to extract the thickness feature value, it can solve the feature value extraction difficult question which caused by two situations of time domain signals aliasing when the coating layer thickness is quite small and signals weak when signal attenuates seriously. And when the extreme point distributed unevenly in the actual detection, some measurements to improve the feature value extraction precision are proposed, which increased the detection signal-to-noise rated effectively. Take the structure of steel shell bonding rubber coating layer as the detection object, the detection experiment is studied to confirm its validity.
A Control System Based on the Fuzzy Self-Tuning PID Controller for Three-Phase Rectifier
Authors: Zhang Guang Guo , Jiang Wei
Published: May 2011

The rectifier implements bidirectional power flow, sinusoidal current and unit power factor control in grid side. This paper describes the design and implementation of the current inner-loop and the voltage outer-loop based on space vector pulse width modulation (SVPWM). A control system based on the fuzzy self-tuning PID for three-phase rectifier is proposed in this paper. The new algorithm based on the fuzzy self-tuning PID can improve the performance of the system. Also, the overshoot of the voltage fluctuation is reduced. Simulation and experimentation results show that the validity of the proposed strategy.
Influence of Ball Milling Parameters on Preparation of Ti50Cu23Ni20Sn7 Amorphous Alloys Powder
Authors: Wang Ge , Li Qiang , Gao Ying , Gao Jing Na , Zhu Yu Ying , Chao Zhi Gang
Published: May 2011

Ti50Cu23Ni20Sn7 amorphous alloys powder was prepared by mechanical alloying (MA) in a high-energy planetary ball mill. Milling parameters such as rotational velocity of ball mill, ball to powder weight ratio as well as milling time were throughly investigated. Mechanism of mechanical alloying was throughly discussed.
Kinematic Analysis of Power Drive Transmission System of High-Performance Four-Wheel Off-Road Vehicles
Authors: Ren Ai Hua , Sun Chuan Qiong , Liu Yong De
Published: May 2011

Firstly the schematic diagram and working principle of this power drive transmission system of high-performance four-wheel off-road vehicles are introduced. And then the kinematic characteristic of the device is analyzed based on an off-road vehicle.
Effect of Dressing Load and Speed on Removal Rate in the Chemical Mechanical Polishing Process
Authors: Tsai Ming Yi , Chen W.K. , Tsai Hung Jung
Published: May 2011

A pad conditioner or diamond disk is needed to regenerate the asperity structure of the pad and recover its designated role in the chemical mechanical polishing process. In this paper, the effect of dressing load and speed on removal rate of oxidized wafers were investigated using a polycrystalline diamond disk and brazed diamond disk. It was found that polycrystalline diamond disk enable the manufacturer to tightly control diamond leveling and the cutter’s shape by comparison with a brazed diamond disk that contains discrete diamond grits of random orientation. Experimental results revealed that for polycrystalline diamond disk, the removal rate of oxidized wafer displayed an almost unchanged curve when the load was less than 4kg, but the removal rate of oxidized wafer for brazed diamond disk initially increased with the dressing load, reaching a maximum value at a dressing load of approximately 4 kg. Then, it decreased slowly with further increases of the dressing load. The removal rate of oxidized wafer remains unchanged with dressing speed.
Web Service Composition Algorithm
Authors: Song Ya Juan , Liu Lei , Yang Dong
Published: May 2011

Web service composition is very important in web service technology. Domain Ontology is used for semantic web service match and automatic web service composition. When a web service is registered, it will be related to the concepts in the domain ontology with its output concepts. To start a semantic match or composition starts, only the related web service with the annotated concept will be used. The approach can deal with not only the sequential but also the parallel service composition problems The proposed approach was verified by experiments and case studies.
Research on Improved Genetic Algorithm for Heterogeneous Open Vehicle Routing Problem
Authors: Ren Chun Yu
Published: May 2011

This paper studies heterogeneous open vehicle routing problem. Since the standard genetic algorithm is short of convergent speed and partial searching ability as well as easily premature, improved genetic algorithm is then adopted as an optimized solution. Firstly, sequence of real numbers coding is used to simplify the problem; it may construct the initial solution pertinently in order to improve the feasibility. The individual amount control choice strategy can guard the diversity of group. The adopting some arithmetic crossover operator can enhance local search ability of the chromosome. Finally, comparing to standard genetic algorithm, simulation results demonstrate the effectiveness and good quality.
A New Architecture for Large Data Warehouse
Authors: Li Gang , Qian Xing San , Ye Chun Ming
Published: May 2011

Data warehouse is playing a more and more important role in company’s decision making; it is the basis for a typical business intelligence solution. The paper points out the reasons why data warehouse projects failed and by analyzing the current data warehouse architectures, as well as technologies used in industry, a new data warehouse architecture is proposed which has many advantages over current ones, for example, it is extensible, reusable, flexible and with high performance and lower cost.
Motion Control System Design of a Humanoid Robot Based on Stereo Vision
Authors: Du Qin Jun , Sun Chao , Huang Xing Guo
Published: May 2011

Vision is an important means of the humanoid robot to get external environmental information; vision system is an important part of humanoid robot. The system of a humanoid robot with the functions of visual perception and object manipulation is very complex because the body of the humanoid robot possesses many joint units and sensors. Two computers linked by Memolink communication unit is adopted to meet the needs of real time motion control and visual information processing tasks. The motion control system included coordination control computer, the distributed DSP joint controllers, DC motor drivers and sensors. Linux and real-time RT-Linux OS are used as the operating system to achieve the real-time control capability.
Numerical Study for Centrifugal Fan Based on Parametric Method
Authors: Zhang Lei , Wang Song Ling , Wu Dian Fa , Zhang Qian
Published: May 2011

This paper takes G4-73 centrifugal fan as the reference model. A practical parametric software platform was developed with VB Programming languages and Fluent software. Numerical simulation based on k-e turbulence model in the same flow rate was taken using the platform. The results show that the total pressure and efficiency of fans will be ideal when the blade angle take 45 degree, which is the design value. However, the best impeller width gotten from numerical simulation is smaller than the design value, that is, 18.5 cm is the most suitable value. The conclusion is of great significance for the subsequent optimization and reconstruction of fan.
Probabilistic Analysis of One-Dimensional Consolidation with Monte Carlo Simulations
Authors: Li Xiao Yong , Hu Liao Qi
Published: May 2011

Themeasured coefficient of consolidation can have a substantial degreeof variation even in a uniform clay layer. This paper examines the variability of one-dimensional consolidationsolutions through a probabilistic analysis. The spatial probabilistic characteristics for the coefficient of vertical consolidation are studied. The influence of a spatially random coefficient of consolidation on one-dimensional consolidation has been studied using the probabilistic method. In the probabilistic analysis, the adequacy of distribution model for coefficient of consolidation is tested using experimental data. A sensitivity analysis of the degree of consolidation to uncertain parameters is presented for clay soil. It is the analysis result that probability distribution type of vertical consolidation has a considerable influence on degree of consolidation. Theresults are discussed in terms of confidence level.
Thermal and Structural Analysis of Asphaltine in Heavy Oil before and after the Hydrogen Donor Catalytic Reaction of Upgrading and Viscosity Reduction under the Effect of Auxiliary Agents
Authors: Zhao Fa Jun , Liu Yong Jian , Qi Xian You , Wang He , Zhao Jie
Published: May 2011

This paper applies high-pressure reactor to simulate conditions of thermal recovery and uses formic acid as hydrogen donor body, self-made oil-soluble organic nickel salt as catalyst and urea as auxiliary agents to conduct the study on of heavy oil. By TG-DTA, IR and NMR spectra, it makes an analysis on thermal transformation behavior and structural changes of asphaltine in heavy oil before and after the reaction of upgrading and viscosity reduction under the effect of auxiliary agents. The results show that the stability of the asphaltine in heavy oil after aquathermolysis reaction of hydrogen donor catalyzing is decreased. Infrared spectroscopy analysis reveals that the absorption peaks of IR functional groups of asphaltine in heavy oil is unchanged and the addition of auxiliary agents basically does not change the structure of asphaltine. NMR structural analysis shows that.
Stability of the Jeffcott Rotor with Local Rubbing
Authors: Li He , Chen Xiao Zhe , Wen Bang Chun
Published: May 2011

The stability and bifurcation behavior of Jeffcott rotor with local rubbing are investigated in terms of Hartman-Grobman theorem in this paper. The case with double zero real part of eigenvalues is analyzed by means of the theory of center manifold and n-dimension Hopf bifurcation. Along with discussion for the effects of parameters on system stability and bifurcation behavior, numerical simulation of rotor locus is conducted and the stability condition is derived.
Research about Implementation Strategies in JMI System of Third-Party Logistics Enterprise
Authors: Gu Yuan Yan , Wu Gong Xin
Published: May 2011

Jointly Managed Inventory(JMI) can balance upstream and downstream enterprises' risk-sharing authority and responsibility by the coordination of their common stock, suppliers and manufacturers, and can share their joint stock of raw materials, manufacturers and sale agents can share and sales their joint stock of finished product. Third-party stock mode is one of the typical implementation modes in JMI system. In the paper, we tried to discusses and analyse the key points in implementation strategies in JMI system of third-party logistics enterprise.
Covalent Bond Cluster Effects and Phase Transitions in Superconductor Mg1-xAlxB2 Compounds
Authors: Bao Yan , Zhao Yuan , Zhu Ni
Published: May 2011

First-principle calculations were performed for the study of the superconductor MgB2 and AlB2. The doping effect of compound Mg1-xAlxB2 was analyzed by supercell method. Band structure, electronic bands structure, total and partial densities of states were calculated and analyzed in detail. Covalent bond effects (CBC) appeared in the electronic bands structure when doping Al to MgB2. It is found that this CBC effects on Mg1-xAlxB2 samples have prominent relations to superconductivity. The study of the density of state indicates that the superconductivity decreases with the increase of compound Al. In particular, there exists the transition of superconductor to non-superconductor with the change of x. The theoretical predictions agreed well with experimental measurements.
Relational Similarity Measure: An Approach Combining Wikipedia and WordNet
Authors: Cao Yan Jiao , Lu Zhao , Cai Song Mei
Published: May 2011

Relational similarities between two pairs of words are the degrees of their semantic relations. Vector Space Model (VSM) is used to measure the relational similarity between two pairs of words, however it needs create patterns manually and these patterns are limited. Recently, Latent Relational Analysis (LRA) is proposed and achieves state-of-art results. However, it is time-consuming and cannot express implicit semantic relations. In this study, we propose a new approach to measure relational similarities between two pairs of words by combining Wordnet3.0 and the Web-Wikipedia, thus implicit semantic relations from the very large corpus can be mined. The proposed approach mainly possesses two characters: (1) A new method is proposed in the pattern extraction step, which considers various part-of-speeches of words. (2)Wordnet3.0 is applied to calculate the semantic relatedness between a pair of words so that the implicit semantic relation of the two words can be expressed. Experimental evaluation based on the 374 SAT multiple-choice word-analogy questions, the precision of the proposed approach is 43.9%, which is lower than that of LRA suggested by Turney in 2005, but the suggested approach mainly focuses on mining the semantic relations among words.
Process Optimization for the Side-Plate of the Core Part in Parallel Flow Evaporator
Authors: Liu Ming Jun , Zhao Zhen Yu , Liu Bai
Published: May 2011

The forming scheme of a side-plate of the core part in parallel flow evaporator was studied. Two forming schemes were compared and the explicit dynamic software DYNAFORM was applied to make simulations about the forming processes. According to comparisons between two forming schemes, the optimized scheme and process parameters were determined. Multi-station dies were designed based on the optimized process. Successful experiments with the dies showed that numerical simulation provided an efficient way for the optimization of the forming scheme in the side-plate production.
Operating Parameters’ Influence on the Specific Volume of Extrusion Puffed Food
Authors: Bu Chi Wu
Published: May 2011

Twin-screw extruder is the main equipment for puffed food processing. Corn powder as the main raw material, barrel temperature, screw speed and feed rate of the extruder as the independent variables, specific volume of the extrusion product as the objective function, experiment has been carried out base on factorial design method. How the independent variables influence the objective function has been analyzed. Values of the operating parameters to get optimal specific volume has been gained.
A Method of Audio Digital Watermark Based on Discrete Wavelet Transform and Quantization Index Modulation
Authors: He Pan Li , Fan Tie Sheng
Published: May 2011

When a digital watermark is directly embedded into low frequency part of audio, sensitive noises maybe occur. In the paper, a method of audio digital watermark based on quantization index modulation is proposed to solve the problem. At first, audio signal is divided to fragment by audio mask effect. Then low frequency part of discrete wavelet transform (DWT) is extracted. Scrambling watermark is embedded into the low frequency part by quantization index modulation (QIM). The experiment results show that the presented method has a good capacity to fight many attacks.
Screening on Three High Efficient Antagonistic Fungi of Colletotrichum gloeosporioides
Authors: Liu Ju Nang , Zhou Jian Hong , Yang Lei , Zhou Guo Ying
Published: May 2011

Camellia anthrax disease is the main disease in producing areas of China. It occurred widespread, caused fruit and flowers dropped seriously, resulting in huge economic losses. In this paper, we separated pathogen with organizational separation method from the diseased leaves and fruit which were infected by Camellia anthrax. Then we proved, by Koch rule, it was pathogen which caused Camellia anthrax disease. According to their morphological characteristics, we identified that it was Colletotrichum gloeosporioides. From the Camellia healthy leaves, we isolated totally 125 strains endophytic fungi. Through the primary screening, 13 strains were detected had inhibited on Colletotrichum gloeosporioides. After the secondary screening, we obtained three strong antagonistic fungi, numbered Cd7, Sy3, Hy19, the inhibition rates separately were 60.3%, 59.7%, 57.8% on the PAD flat.
Adiabatic Shear Localization in High Speed Cutting of Hardened Steel
Authors: Duan Chun Zheng , Kong Wei Sen , Wang Zhao Xi , Wang Min Jie
Published: May 2011

The formation and development of adiabatic shear localization in serrated chips have great significance to study of mechanism of high speed cutting. This paper investigates the theory prediction and experimental verification of the critical cutting speed of adiabatic shear localization, distribution of adiabatic shear band in serrated chip and the geometry of adiabatic shear band during high speed cutting of hardened steel. The results indicated that the theoretical prediction of critical cutting speed is consistent with the experimental results.With the increase of cutting speed, the width and spacing of adiabatic shear bands in the serrated chips decrease linearly. There are two types of adiabatic shear bands during the formation and development of adiabatic shear localization, i.e. the deformation shear band and the transformed shear band.
Appliance on Evaluation of Type Selection for Agricultural Machinery Based on Grey Relational Analysis Method
Authors: Xie Yan , Li Mu
Published: May 2011

The type selection for agricultural machinery generally depends on the selector’s experiences at the present time. It exist some subjectivity and one-sidedness unavoidably. On the basis of the characteristics of complexity and the uncertainty of optimal selection for agricultural machinery, grey relational analysis model in agricultural machinery multi-type selection application has been put forward in this paper. The index system of influencing agricultural machinery type selection is determined. Application model and procedures of the grey relational analysis method are introduced. According to the degree how close it is with the ideal dot, the optimal type is easy to be selected out. Through the optimization analysis type selection for the agricultural transporter, it is proved that the optimal type selection for agricultural machinery based on grey relational analysis has the strong recognition judgment ability. It is convenient, quantitative, and strict. It provided a new method and a possible new way for evaluation of agricultural machinery type selecting．
Renal Function but Not Asymmetric Dimethylarginine Is Independently Associated with Retinopathy in Type 2 Diabetes
Authors: Krzyzanowska Katarzyna , Mittermayer Friedrich , Schernthaner Gerit H. , Brunner Simon , Brix Johanna M. , Aschauer Stefan , Höllerl Florian , Wolzt Michael , Schernthaner Guntram
Published: May 2011

Background. Asymmetric dimethylarginine (ADMA) is associated with macrovascular disease and possibly with microangiopathy in type 2 diabetes (T2DM). We tested the hypothesis that ADMA is related to diabetic retinopathy (DR) independently of macrovascular disease.Methods. This cross-sectional study included 127 T2DM patients selected to achieve equal distributions of patients with and without macrovascular disease in the groups with and without DR.Results. Patients with DR had increased ADMA, longer diabetes duration, and reduced glomerular filtration rate (GFR). ADMA correlated with GFR (; ), diabetes duration (; ), and age (; ). Logistic regression analysis revealed an association of ADMA with DR. After adjustment for macrovascular disease, this association remained significant (OR 1.48; 95% CI: 1.02–2.15; ). Inclusion of GFR and T2DM duration into the model abolished this significant relationship. GFR remained the only independent predictor for DR. A 10 mL/min/1.73 m2GFR decrease was associated with DR in a multivariate model (OR 1.30; 95% CI: 1.08–1.56; ).Conclusions. These findings indicate an association between ADMA and DR in T2DM independent of macrovascular disease. This relationship is modified by GFR, the only parameter significantly related to DR in multivariate analysis.
Relationship between Angiotensin-Converting Enzyme Insertion/Deletion Gene Polymorphism and Susceptibility of Minimal Change Nephrotic Syndrome: A Meta-Analysis
Authors: Zhou Tian-Biao , Qin Yuan-Han , Su Li-Na , Lei Feng-Ying , Huang Wei-Fang , Zhao Yan-Jun
Published: May 2011

Aim. This meta-analysis was performed to evaluate the association between ACE I/D gene polymorphism and MCNS susceptibility.Method. A predefined literature search and selection of eligible relevant studies were performed to collect the data from electronic databases.Results. Six articles were identified for the analysis of association between ACE I/D gene polymorphism and MCNS risk, including 4 for Asians, one in Caucasian population and one for Africans. There was a markedly positive association between D allele or DD genotype and MCNS susceptibility in Asians (D:P=.01, DD:P=.02), but not for Caucasians and Africans (Caucasians: D:P=.16, DD:P=.98; Africans: D:P=.81, DD:P=.49). Furthermore, the II genotype seemed not to play a protective role against MCNS risk for Asians, Caucasians and Africans (P=.12,P=.09,P=.76, resp.). Interestingly, there was also significant association between ACE I/D gene polymorphism and MCNS susceptibility in overall populations (D:P=.007, DD:P=.04, II:P=.03).Conclusion. D allele or DD genotype might be a significant genetic molecular marker for MCNS susceptibility in Asians and overall populations, but not for Caucasians and Africans. More larger and rigorous genetic epidemiological investigations are required to further explore this association.
Ram Sperm Motility Parameters under The Influence of Epidermal Growth Factor
Authors: Špaleková Eliška , Makarevich Alexander V. , Lukáč Norbert
Published: May 2011

Epidermal growth factor (EGF) is one of the important cytokines that play a role in fertility. It is known that EGF affects both male and female reproduction, but its effect on sperm parameters is not fully understood. Up to the present, the effect of EGF on ram sperm motility parameters has not been published. We analyzed motility parameters of ejaculates after 24, 48, and 72 hours from the EGF addition. EGF was added to chilled ram sperm at concentrations of 0, 100, 200, and 400 ng⋅ml−1. Analyses were realized using computer, assisted semen analyzer (CASA)—Hamilton Thorn motility analyzer (version 7). The effect of EGF was already visible after 30 min of incubation. Significant effect on ram sperm total motility and progressive movement was observed at higher EGF concentrations after 48 h of incubation. Our results show that EGF affects sperm motility parameters depending on concentration and time of exposure.
Wat op dees (van) aarde beteken die einde van tradisionele metafisiese taal oor God? In gesprek met die Nuwe-Testamentikus Andries Gideon van Aarde oor sy verstaan van ‘n postsekulêre spiritualiteit
Authors: Veldsman Daniël P.
Published: May 2011

What does the end of traditional metaphysical language about God mean? In conversation with New Testament scholar Andries Gideon van Aarde on his understanding of a postsecular spiritualitySouth African New Testament scholar Van Aarde’s explorative search for a new direction in theological reflection is explicated in this article with reference to his discussion of Peter Berger and Charles Taylor’s contemporary contributions, which Van Aarde takes as vantage point to articulate the meaning of his ‘courage to be a religious person today’. The articulation of his ‘courage’ to pursue a post-theistic understanding of a contemporary Christian religiosity (read: spirituality) that is non-fundamentalistic, non-populist and post-secular is discussed. At the same time, the basic tenets of his explorations are indicated, being constituted – negatively – by a de-centering of the power of institutional religion and, positively, by the enchantment of a Biblical hermeneutics that does not emphasise a proposition-like and moral code-like reading strategy. Finally, his ‘new direction’, which finds expression in the articulation of a ‘spirituality of living faith’, is scrutinised. It exposes the shortcomings in his (individualistic) exposition within the new correlation of modernisation and pluralism, causing it subsequently to bypass the necessary contemporary outcome in social embodiment.
The influence of cultural practices on the HIV and AIDS pandemic in Zambia
Authors: Moyo Nolipher , Müller Julian C.
Published: May 2011

Culture plays a significant role in people’s lives in Zambia and in Africa as a whole. Consequently, there is a need to take Zambian or African culture seriously in order to look at the salient elements of cultural practices in rites of passage that influence the spread of HIV and AIDS. This article analyses four rites of passage associated with birth, puberty, marriage and death. There are numerous rites of passage in Zambian culture. Some of these rites help to curb the spread of HIV and AIDS, whilst others exacerbate the spread of the virus. Using the Reformed Church in Zambia Bible Study Method of Subgroups, discussions were held that allowed victims of cultural practices to tell their stories using the narrative model. This article sought to shed light on cultural practices that exacerbate HIV and AIDS and more importantly, provide culturally sensitive alternatives to these harmful practices.
Prevalence of Connective Tissue Diseases in Egyptian Patients Presenting with Fever of Unknown Origin
Authors: Abdelbaky Mohamad S. , Mansour Howaida E. , Ibrahim Shafika I. , Hassan Iman A.
Published: May 2011

Objective

To estimate the prevalence of connective tissue diseases in patients presenting with fever of unknown origin (FUO).

Patients and Methods

In this study thirty patients diagnosed as FUO (Group 1), in 2008, were included in an observational study and diagnostic workup. Additionally, retrospective analysis of seventy patients’ files (Group 2), for patients who presented with prolonged unexplained pyrexia to the same hospital in the previous two years, was performed. Patients were subjected to: full clinical assessment including full history taking, thorough clinical examination, laboratory investigations including the basic investigations for patients with prolonged fever, complete blood count, erythrocytes sedimentation rate, urine analysis and culture, blood culture, sputum culture and plain chest X ray. Further diagnostic work up and/or procedures were requested according to the potential diagnostic clues (PDC) present in every patient.

Results

Out of 100 FUO patients, 50% were found to have infectious diseases, 24% were found to have connective tissue diseases, 8% miscellaneous causes and 7% neoplastic diseases ( P < 0.05). In 11 patients no definite cause for FUO could be identified. Connective tissue patients were: eight systemic lupus patients (33.3%), five patients with familial mediterranean fever (20.8%), four patients with rheumatoid arthritis (16.6%), three patients (12.5%) with Still's disease and Rheumatic fever and one patient with Behçet syndrome/Crohn's disease (4.3%), ( P < 0.05).

Conclusions

Despite the advanced technology, FUO remains a challenging medical problem. Infections were the most common cause of FUO in Egypt, confirming the trends found in other parts of the world. There was an increased prevalence of connective tissue patients presented with prolonged unexplained fever. A keen clinical eye, meticulous history taking and repeated physical examination remained the most important diagnostic tools in FUO patients.
The biology of Canadian weeds. 128. Leucanthemum vulgare Lam.
Authors: Clements David R. , Cole Dan E. , King Jane , McClay Alec
Published: May 2011

Leucanthemum vulgare Lam. (Asteraceae), known as ox-eye daisy, is a familiar perennial herb with white ray florets and yellow disc florets. It commonly inhabits roadside ver ges, pastures and old fields from Newfoundland to British Columbia, and also as far north as the Yukon Territory. Introduced from Europe, L. vulgare was well established in North America by 1800. The Canadian distribution of L. vulgare has expanded in many areas recently, particularly in western Canada. It can form dense populations that may reduce diversity of natural vegetation or pasture quality, and also serves as a host and reservoir for several species of polyphagous gall-forming Meloidogyne nematodes that feed on crops. It is considered a noxious weed under provincial legislation in Quebec, Manitoba, Alberta and British Columbia, as well as under the Canada Seeds Act. Control efforts are sometimes complicated by difficulties in distinguishing ox-eye daisy from some forms of the commercially available Shasta daisy ( L. × superbum).
Writing Gave Me a Voice: A Spanish‐Dominant Teachers Writing Workshop
Authors: SPENCE LUCY K. , CARDENAS‐CORTEZ KAREN
Published: May 2011

Debate regarding appropriate instructional practices for linguistically and culturally diverse students led to a study of a bilingual Latina teacher's third‐grade writing workshop. Qualitative research methods were used to provide a rich description of context, instruction, and participation. This was combined with the teacher's personal narrative of her own experience becoming a bilingual writer and its influence upon her teaching. Her instructional approach was embedded in social practice. Dramatizations, visual representations, computer‐based research, and traditional texts afforded exposure to ways of speaking, being, and understanding the world. Students were provided with many opportunities to write within a community of practice, focusing on persuasive essay and other genres such as personal narrative and informational reports.
Drop size distribution comparisons between Parsivel and 2-D video disdrometers
Authors: Thurai M. , Petersen W. A. , Tokay A. , Schultz C. , Gatlin P.
Published: May 2011

Abstract. Measurements from a 2-D video disdrometer (2DVD) have been used for drop size distribution (DSD) comparisons with co-located Parsivel measurements in Huntsville, Alabama. The comparisons were made in terms of the mass-weighted mean diameter, Dm, the standard deviation of the mass-spectrum, σm, and the rainfall rate, R, all based on 1-min DSD from the two instruments. Time series comparisons show close agreement in all three parameters for cases where R was less than 20 mm h−1. In four cases, discrepancies in all three parameters were seen for "heavy" events, with the Parsivel showing higher Dm, σm and R, when R reached high values (particularly above 30 mm h−1). Possible causes for the discrepancies include the presence of a small percentage of non-fully melted hydrometers, with higher than expected fall velocity and with very different axis ratios as compared with rain, indicating small hail or ice pellets or graupel. We also present here Parsivel-to-Parsivel comparisons as well as comparisons between two 2DVD instruments, namely a low-profile unit and the latest generation, "compact unit" which was installed at the same site in November 2009. The comparisons are included to assess the variability between the same types of instrument. Correlation coefficients and the fractional standard errors are compared.
Quantifying in-situ gas hydrates at active seep sites in the eastern Black Sea using pressure coring technique
Authors: Heeschen K. , Haeckel M. , Klaucke I. , Ivanov M. K. , Bohrmann G.
Published: May 2011

Abstract. In the eastern Black Sea, we determined methane (CH4) concentrations, gas hydrate volumes and their vertical distribution from combined gas and chloride (Cl−) measurements within pressurized sediment cores. The total gas volume collected from the cores corresponds to concentrations of 1.2–1.4 mol of methane per kg porewater at in-situ pressure, which is equivalent to a gas hydrate saturation of 15–18% of pore volume and amongst the highest values detected in shallow seep sediments. At the central seep site, a high-resolution Cl− profile resolves the upper gas hydrate stability boundary and a continuous layer of hydrates in a sediment column of 120 cm thickness. Including this information, a more precise gas hydrate saturation of 22–24% pore volume can be calculated. This is higher in comparison to a saturation calculated from the Cl− profile alone, resulting in 14.4%. The likely explanation is an active gas hydrate formation from CH4 gas ebullition. The hydrocarbons at Batumi Seep are of shallow biogenic origin (CH4 > 99.6%), at Pechori Mound they originate from deeper thermocatalytic processes as indicated by the lower ratios of C1 to C2–C3 and the presence of C5.
Modelling post-fire vegetation recovery in Portugal
Authors: Bastos A. , Gouveia C. , DaCamara C. C. , Trigo R. M.
Published: May 2011

Abstract. Wildfires in Mediterranean Europe have been increasing in number and extension over the last decades and constitute one of the major disturbances of these ecosystems. Portugal is the country with more burnt area in the last decade and the years of 2003 and 2005 were particularly devastating, the total burned areas of 425 000 and 338 000 ha being several times higher than the corresponding average. The year of 2005 further coincided with one of the most severe droughts since early 20th century. Due to different responses of vegetation to diverse fire regimes and to the complexity of landscape structures, fires have complex effects on vegetation recovery. Remote sensing has revealed to be a powerful tool in studying vegetation dynamics and in monitoring post-fire vegetation recovery, which is crucial to land-management and to prevent erosion. The main goals of the present work are (i) to assess the accuracy of a vegetation recovery model previously developed by the authors; (ii) to assess the model's performance, namely its sensitivity to initial conditions, to the temporal length of the input dataset and to missing data; (iii) to study vegetation recovery over two selected areas that were affected by two large wildfire events in the fire seasons of 2003 and 2005, respectively. The study relies on monthly values of NDVI over 11 yr (1998–2009), at 1 × 1 km spatial resolution, as obtained by the VEGETATION instrument. According to results from sensitivity analysis, the model is robust and able to provide good estimations of recovery times of vegetation when the regeneration process is regular, even when missing data is present. In what respect to the two selected burnt scars, results indicate that fire damage is a determinant factor of regeneration, as less damaged vegetation recovers more rapidly, which is mainly justified by the high coverage of Pinus Pinaster over the area, and by the fact that coniferous forests tend to recover slower than transitional woodland-shrub, which tend to dominate the areas following the fire event.
Probabilistic assessments of climate change impacts on durum wheat in the Mediterranean region
Authors: Ferrise R. , Moriondo M. , Bindi M.
Published: May 2011

Abstract. Recently, the availability of multi-model ensemble prediction methods has permitted a shift from a scenario-based approach to a risk-based approach in assessing the effects of climate change. This provides more useful information to decision-makers who need probability estimates to assess the seriousness of the projected impacts. In this study, a probabilistic framework for evaluating the risk of durum wheat yield shortfall over the Mediterranean Basin has been exploited. An artificial neural network, trained to emulate the outputs of a process-based crop growth model, has been adopted to create yield response surfaces which are then overlaid with probabilistic projections of future temperature and precipitation changes in order to estimate probabilistic projections of future yields. The risk is calculated as the relative frequency of projected yields below a selected threshold. In contrast to previous studies, which suggest that the beneficial effects of elevated atmospheric CO2 concentration over the next few decades would outweigh the detrimental effects of the early stages of climatic warming and drying, the results of this study are of greater concern.
A statistical permafrost distribution model for the European Alps
Authors: Boeckli L. , Brenning A. , Gruber S. , Noetzli J.
Published: May 2011

Abstract. Permafrost distribution modeling in densely populated mountain regions is an important task to support the construction of infrastructure and for the assessment of climate change effects on permafrost and related natural systems. In order to analyze permafrost distribution and evolution on an Alpine-wide scale, one consistent model for the entire domain is needed. We present a statistical permafrost model for the entire Alps based on rock glacier inventories and rock surface temperatures. Starting from an integrated model framework, two different sub-models were developed, one for debris covered areas (debris model) and one for steep rock faces (rock model). For the debris model a generalized linear mixed-effect model (GLMM) was used to predict the probability of a rock glacier being intact as opposed to relict. The model is based on the explanatory variables mean annual air temperature (MAAT), potential incoming solar radiation (PISR) and the mean annual sum of precipitation (PRECIP), and achieves an excellent discrimination (area under the receiver-operating characteristic, AUROC = 0.91). Surprisingly, the probability of a rock glacier being intact is positively associated with increasing PRECIP for given MAAT and PISR conditions. The rock model was calibrated with mean annual rock surface temperatures (MARST) and is based on MAAT and PISR. The linear regression achieves a root mean square error (RMSE) of 1.6 °C. The final model combines the two sub-models and accounts for the different scales used for model calibration. Further steps to transfer this model into a map-based product are outlined.
Unresolved questions in the regulation of skeletal muscle insulin action by reactive oxygen species
Authors: Gallero Samantha , Persson Kaspar W. , Henríquez‐Olguín Carlos
Published: May 2024

Reactive oxygen species (ROS) are well‐established signaling molecules implicated in a wide range of cellular processes, including both oxidative stress and intracellular redox signaling. In the context of insulin action within its target tissues, ROS have been reported to exert both positive and negative regulatory effects. However, the precise molecular mechanisms underlying this duality remain unclear. This Review examines the complex role of ROS in insulin action, with a particular focus on skeletal muscle. We aim to address three critical aspects: (a) the proposed intracellular pro‐oxidative redox shift elicited by insulin, (b) the evidence supporting that redox‐sensitive cysteine modifications impact insulin signaling and action, and (c) cellular mechanisms underlying how ROS can paradoxically act as both enhancers and inhibitors of insulin action. This Review underscores the urgent need for more systematic research to identify specific reactive species, redox targets, and the physiological significance of redox signaling in maintaining insulin action and metabolic health, with a particular emphasis on human skeletal muscle.
Multifunctional Design of Triply Periodic Minimal Surface Structures for Temporary Pediatric Fixation Devices
Authors: Ebrahimzadeh Dehaghani Ali , Javanbakht Zia , Barzan Martina , Lloyd David G. , Feih Stefanie
Published: May 2024

Fracture fixation and limb deformity correction in pediatric orthopedics often use temporary metallic fixation devices. These devices’ higher stiffness compared to cortical bone leads to stress shielding, causing significant bone density reduction, periprosthetic loosening, and bone growth interference. The 3D‐printed triply periodic minimal surface (TPMS) structures present a promising engineering solution to match bone stiffness while ensuring reliable implant strength. In this study, finite‐element modeling and experimental testing are employed to identify optimal multifunctional TPMS‐based lattices that meet the required design constraints of 1) stiffness in the range of cortical bone, 2) strength in the range of cortical bone, 3) minimum osteointegration to facilitate the implant removal after healing, and 4) manufacturability with limited defect sensitivity. Six different types of TPMS structures in Ti–6Al–4V material manufactured via laser powder bed fusion are evaluated for their ability to target the lower and upper bounds of pediatric cortical bone stiffness. Lattices based on the Primitive unit cell design are superior, demonstrating the highest strength/stiffness ratio, best manufacturability, and potentially reduced osteointegration due to larger pore size, smaller surface area, and smallest negative Gaussian curvature compared to other investigated TPMS types.
Microstructure and Properties Evolution of 7075 Al Alloy in Hot Rolling and Short Process Heat Treatment
Authors: Shao Bin , Liu Jiabin , Su Heng , Zong Yingying , Shan Debin , Guo Bin
Published: May 2024

7075 aluminum alloy is widely used in the aerospace field because of its low density, high specific strength, high fracture toughness, and good machinability. Herein, the evolution of the microstructure and properties of 7075 aluminum alloy at different temperatures is systematically studied. Based on the rolling and heat treatment process, a short process of rolling and heat treatment is proposed, which can significantly improve the properties. The study finds that the nanophases are distributed in a “streamline‐like” or “lip‐like” shape after rolling. When the rolling temperature is below 550 °C, the phases are mainly Al7Cu2Fe, the grain size does not change significantly, and shear bands appear inside the grains. When rolled at 600 °C, the grains coarsen significantly and the shear bands become longer, resulting in overburning and cracking. The broken phases are smoothed when rolled at 550 °C. It is observed that the nanophases becomes larger. Due to the strain‐strengthening effect, the ultimate tensile strength increases by 6% with little change in elongation. In industrial production, direct aging treatment after high‐temperature rolling can reduce energy consumption and improve production efficiency.
Tumor Cell Membrane‐Camouflaged Vortex Magnetic Nanoannulars Programmed by Low‐Frequency Magnetic Field: A Novel Anti‐Cancer Delivery System in Triple‐Negative Breast Cancer
Authors: Lu Yunshu , Gu Fenfen , Ma Yuwei , Da Xianhong , Li Ruonan , Jiang Lan , Li Xiang , Liu Yan
Published: May 2024

Triple‐negative breast cancer (TNBC), a highly aggressive form of breast cancer, currently lacks targeted therapies and is associated with high recurrence rates in medical practice. In this study, the effectiveness of a specially developed magnetic nanodrug, namely doxorubicin (DOX)‐loaded Fe3O4 vortex magnetic nanoannulars coated with a cancer cell membrane (DOX‐VMAs@CM), against cancer under a varying low‐frequency magnetic field (MF), is investigated. This advanced nanodrug can specifically target and accumulate in tumors. Additionally, it considerably improves tumor suppression compared with that of DOX chemotherapy alone, indicating the possibility of homologous targeting of the cancer cell membrane and the vibrating effect of the MF. The DOX‐VMAs@CM nanoparticles (NPs) exhibit exceptional safety characteristics because of their ability to specifically target tumors. The results of RNA sequencing suggest that the potential mechanisms may involve cellular respiration, cell cycle, and ferroptosis regulation. Altogether, chemotherapy is successfully optimized by implementing a delivery system and MF intervention, and the developed DOX‐VMAs@CM NPs hold significant potential for use in the clinical treatment of TNBC.
Functional Integration of Synthetic Cells into 3D Microfluidic Devices for Artificial Organ‐On‐Chip Technologies
Authors: Hakami Niki , Burgstaller Anna , Gao Ning , Rutz Angela , Mann Stephen , Staufer Oskar
Published: May 2024

Microfluidics plays a pivotal role in organ‐on‐chip technologies and in the study of synthetic cells, especially in the development and analysis of artificial cell models. However, approaches that use synthetic cells as integral functional components for microfluidic systems to shape the microenvironment of natural living cells cultured on‐chip are not explored. Here, colloidosome‐based synthetic cells are integrated into 3D microfluidic devices, pioneering the concept of synthetic cell‐based microenvironments for organs‐on‐chip. Methods are devised to create dense and stable networks of silica colloidosomes, enveloped by supported lipid bilayers, within microfluidic channels. These networks promote receptor‐ligand interactions with on‐chip cultured cells. Furthermore, a technique is introduced for the controlled release of growth factors from the synthetic cells into the channels, using a calcium alginate‐based hydrogel formation within the colloidosomes. To demonstrate the potential of the technology, a modular plug‐and‐play lymph‐node‐on‐a‐chip prototype that guides the expansion of primary human T cells by stimulating receptor ligands on the T cells and modulating their cytokine environment is presented. This integration of synthetic cells into microfluidic systems offers a new direction for organ‐on‐chip technologies and suggests further avenues for exploration in potential therapeutic applications.
Development of Nanopillar Arrays Nanopatterning Without Lift‐Off for Transferable GaN‐Based µLEDs
Authors: Labchir Nabil , Hammami Saber , Baril Kilian , Wehbe Maya , Labau Sebastien , Reche Jerome , Petit‐Etienne Camille , Panabière Marie , Coulon Pierre‐Marie , Alloing Blandine , Munoz Daniel Pino , Zuniga‐Perez Jesus , Gergaud Patrice , Charles Matthew , Gourgon Cécile
Published: May 2024

The mass production of µLEDs requires an upscaling approach on 200 mm wafers, which implies the deployment of a technology that achieves zero defectivity without liftoff. In this report, Nanoimprint lithography (NIL) processing is successfully optimized for nanostructuring GaN‐based Silicon‐On‐Insulator (SOI) substrates. The etching of SiO2/GaN/AlN/Si/SiO2layers using different plasmas is conducted and multi‐layer nanopillars 100–200 mm in diameter are fabricated. This approach generates zero‐defect arrays of pillars, which is particularly advantageous for the growth process. In addition, the SiO2at the bottom of the pillar allows it to twist during the subsequent GaN regrowth, as this layer becomes soft at the growth temperature >1000 °C. This ability to deform enables a coalescence of pillars into layers with reduced dislocation density. As a result, high‐quality GaN microplatelets and µLEDs are grown via a bottom‐up approach based on pendeoepitaxy using metal–organic vapor phase epitaxy (MOVPE). The fabricated µLEDs have a very smooth surface with a roughness of 0.6 nm which facilitated the implementation of an easy and simple transfer protocol. Adhesive tape and metalmetal bonding, are used to bond the µLEDs onto a metal‐coated silicon substrate. The reported findings offer exciting new insights into the development of high‐performance displays.