检索结果-南通市图书馆

Bone cement adhesion on ceramic surfaces—Surface activation of retention surfaces of knee endoprostheses by atmospheric pressure plasma *** surface treatment

在线全文

学校读者我要写书评

暂无评论

Journal of Advanced Ceramics 2016年第2期5卷 137-144页

作者： B.marx C.marx R.marx U.REISGEN D.C.WIRTZ ISF Welding and Joining Institute RWTH Aachen University Pontstrasse 49 52062 Aachen GermanyCC&A Medical Components Ltd. Center for Biomedical Engineering Pauwelsstrasse 17 52074 Aachen Germany CC&A Medical Components Ltd. Center for Biomedical Engineering Pauwelsstrasse 17 52074 Aachen Germany ISF Welding and Joining Institute RWTH Aachen University Pontstrasse 49 52062 Aachen Germany Orthopaedics and Traumatology Clinic University Hospital Bonn Sigmund-Freud-Strasse 25 53127 Bonn Germany

CoCrMo alloys are contraindicated for allergy sufferers. For these patients, uncemented and cemented prostheses made of titanium alloy are indicated. Knee prostheses machined from that alloy, however, may have poor tribological behavior. Therefore, for allergy sufferers, knee replacements in form of cemented high-strength oxide ceramic prostheses which reveal excellent tribological behavior are suitable. In addition, the rate of particle induced aseptic loosening may be reduced. For adhesion of bone cement, the smooth ceramic surface, however, exposes inefficient mechanical retention spots as compared with a textured metal surface. Undercuts generated by corundum blasting, which in the short and intermediate term are highly efficient on a CoCrMo surface, are not appropriate on a ceramic surface due to the brittleness of ceramics. The corresponding textures may initiate cracks which will weaken the strength of a ceramic prosthesis. Due to the lack of textures, mechanical retention is poor or even not existent. Micromotions are facilitated and early aseptic loosening is predictable. Instead silicoating of the ceramic surface will allow specific adhesion and result in better hydrolytic stability of bonding, thereby preventing early aseptic loosening. Silicoating, however, presupposes a clean and chemically active surface which may be achieved by atmospheric plasma or thermal surface treatment. In order to evaluate the effectiveness of silicoating, the bond strengths of atmospheric plasma versus thermal surface treated and silicoated ZPTA (zirconia platelets toughened alumina) surfaces were compared with “as-fired” surfaces by utilizing TiAlV probes (diameter: 6 mm) for traction-adhesive strength test. After preparing samples for traction-adhesive strength test (sequence: ceramic substrate, silicate layer and penetrated silane, protective lacquer (PolyMA), bone cement, TiAlV probe), they were aged up to 150 days at 37°C in Ringer’s solution. The bond strengths observed

关键词： total knee replacement out of oxide ceramics aseptic loosening allergenic potential atmospheric plasma treatment silicoating hydrolytic stability

Effect of age and different doses of dietary vitamin E on breast meat qualitative characteristics of finishing broilers

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Animal Nutrition 2021年第1期7卷 163-167页

作者： Vivian Vieira Francielle O.marx Lucas S.Bassi Marley C.Santos alexandre Oba Simone Gisele de Oliveira alex Maiorka Federal University of Paraná Curitiba80035-050Brazil State University of Londrina Londrina86055-900Brazil

The supplementation of vitamin E on broiler chicken diets is essential to the prevention of lipid oxidation reactions in the meat and improvement of meat *** objective of this study was to assess the effect of different doses of dietary vitamin E on breast meat quality of broiler chickens in the finishing *** doses of vitamin E were used(30,90,150,210,and 270 mg/kg feed)in broilers'diets from 42 to 54 d of age.A completely randomized design was conducted,followed by a split-plot,where the vitamin E dose was considered as the whole plot,and broilers'age at slaughter was the *** meat quality was assessed at 4 different ages(45,48,51,and 54 d old),using 50 birds per age,totaling 200 *** quality characteristics evaluated were:pH at 24 h post mortem,color(brightness,redness,and yellowness),water holding capacity,cooking loss,shear force,and lipid *** was no interaction between age and dose of vitamin E for meat quality characteristics(P>0.05).The age at slaughter had a quadratic effect(P<0.05)on pH,brightness,redness,and water holding *** pH values were higher in the breast meat of older birds(51 and 52 d old),breast meat of younger birds(48 d)had a more reddish *** force value was higher in breast meat of birds slaughtered at later ages(P<0.01),as a linear age-effect was *** increased linearly(P<0.05)with higher vitamin doses,whereas treatments did not alter yellowness,cooking loss,and lipid *** this study,increasing vitamin E doses in the finishing period increased the brightness of broiler breast meat,whereas slaughtering at later ages resulted in greater meat pH and shear force value.

关键词： Alpha-tocopherol Broiler chicken Meat quality Oxidation Vitamin

A PLS blockchain for IoT applications:protocols and architecture

在线全文

学校读者我要写书评

暂无评论

Cybersecurity 2018年第1期1卷 993-1009页

作者： alex Shafarenko Department of Computer Science University of HertfordshireHatfield AL109ABUK

This paper proposes an architecture and a protocol suite for a permissioned blockchain for a local IoT *** architecture is based on a sealed Sequencer and a Fog Server running(post-quantum)Guy Fawkes *** blocks of the blockchain are stored in networked Content Addressable Storage alongside any user data and validity *** maintain that a typical IoT device can,despite its resource limitations,use our blockchain protocols directly,without a trusted *** includes posting and monitoring transactions as well as off-chain(post-quantum)emergency communications without an explicit public key.

关键词： Blockchain Guy Fawkes protocol Post-quantum HORS-OTS LoRa Concurrent transmission

Indexing structures for the PLS blockchain

在线全文

学校读者我要写书评

暂无评论

Cybersecurity 2021年第1期4卷 561-579页

作者： alex Shafarenko University of Hertfordshire AL109AB HertfordshireUK

This paper studies known indexing structures from a new point of view:minimisation of data exchange between an IoT device acting as a blockchain client and the blockchain server running a protocol suite that includes two Guy Fawkes protocols,PLS and *** PLS blockchain is not a cryptocurrency instrument;it is an immutable ledger offering guaranteed non-repudiation to low-power clients without use of public key *** novelty of the situation is in the fact that every PLS client has to obtain a proof of absence in all blocks of the chain to which its counterparty does not contribute,and we show that it is possible without traversing the block’s Merkle *** obtain weight statistics of a leaf path on a sparse Merkle tree theoretically,as our ground *** the theory we quantify the communication cost of a client interacting with the *** show that large savings can be achieved by providing a bitmap index of the tree compressed using Tunstall’s *** further show that even in the case of correlated access,as in two IoT devices posting messages for each other in consecutive blocks,it is possible to prevent compression degradation by re-randomising the IDs using a pseudorandom bijective *** propose a low-cost function of this kind and evaluate its quality by simulation,using the avalanche criterion.

关键词： PLS blockchain Guy Fawkes protocol Content-addressable storage Data-structure statistics Tunstall coding Pseudorandom bijections

Conics on Barth-Bauer octics

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2024年第7期67卷 1507-1524页

作者： alex Degtyarev Department of Mathematics Bilkent UniversityAnkara06800Turkey

We analyze the configurations of conics and lines on a special class of Kummer octic surfaces. In particular, we bound the number of conics by 176 and show that there is a unique surface with 176 conics, all irreducible: it admits a faithful action of one of the Mukai groups. Therefore, we also discuss conics and lines on Mukai surfaces: we discover a double plane(ramified at a smooth sextic curve) that contains 8,910 smooth conics.

关键词： K3-surface octic surface Kummer surface conic Mukai group

Data Warehouse Design for Big Data in Academia

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2022年第4期71卷 979-992页

作者： alex Rudniy Department of Computing Sciences University of ScrantonScranton18510PAUSA

This paper describes the process of design and construction of a data warehouse(“DW”)for an online learning platform using three prominent technologies,Microsoft SQL Server,MongoDB and Apache *** three systems are evaluated for corpus construction and descriptive *** case also demonstrates the value of evidence-centered design principles for data warehouse design that is sustainable enough to adapt to the demands of handling big data in a variety of ***,the paper addresses maintainability-performance tradeoff,storage considerations and accessibility of big data *** this NSF-sponsored work,the data were processed,transformed,and stored in the three versions of a data warehouse in search for a better performing and more suitable *** data warehouse engines-a relational database,a No-SQL database,and a big data technology for parallel computations-were subjected to principled ***,construction and evaluation of a data warehouse were scrutinized to find improved ways of storing,organizing and extracting *** work also examines building corpora,performing ad-hoc extractions,and ensuring *** was found that Apache Hive demonstrated the best processing time followed by SQL Server and *** the aspect of analytical queries,the SQL Server was a top performer followed by MongoDB and *** paper also discusses a novel process for render students anonymity complying with Family Educational Rights and Privacy Act *** phases for DW design are recommended:1)Establishing goals at the outset based on Evidence-Centered Design principles;2)Recognizing the unique demands of student data and use;3)Adopting a model that integrates cost with technical considerations;4)Designing a comparative database and 5)Planning for a DW design that is *** for future research include attempting DW design in contexts involving larger data sets,more refined operations,and ensu

关键词： Big data data warehouse MongoDB Apache hive SQL server

A New Approach to Multivariate Network Traffic Analysis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Computer Science & Technology 2019年第2期34卷 388-402页

作者： Jinoh Kim alex Sim Department of Computer Science Texas A&M University Commerce 75428 U.S.A. Computational Research Division Lawrence Berkeley National Laboratory Berkeley CA 94720 U.S.A.

Network traffic analysis is one of the core functions in network monitoring for effective network operations and *** online traffic analysis has been widely studied,it is still intensively challenging due to several *** of the primary challenges is the heavy volume of traffic to analyze within a finite amount of time due to the increasing network *** important challenge for effective traffic analysis is to support multivariate functions of traffic variables to help administrators identify unexpected network events *** this end,we propose a new approach with the multivariate analysis that offers a high-level summary of the online network *** this approach,the current state of the network will display patterns compiled from a set of traffic variables,and the detection problems in network monitoring(e.g.,change detection and anomaly detection)can be reduced to a pattern identification and classification *** this paper,we introduce our preliminary work with clustered patterns for online,multivariate network traffic analysis with the challenges and limitations we *** then present a grid-based model that is designed to overcome the limitations of the clustered pattern-based *** will discuss the potential of the new model with respect to the technical challenges including streaming-based computation and robustness to outliers.

关键词： network traffic analysis multivariate analysis time-series similarity network monitoring

Generation scenarios of anodic structures and experimental realization of turbulence in unmagnetized plasma

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Plasma Science and Technology 2020年第8期22卷 90-98页

作者： Prince alex Suraj Kumar SINHA Departimento di Fisica G.Occhialini Universita degli studi di MilanoBicoccaI-20126Italy Department of Physics Pondicherry UniversityKalapetPuducherry 605014India

In the present work,we report development of a DC glow discharge plasma(GDP)set-up to study controlled evolution of anodic structures having distinctive geometry,size and layers,generated in front of a positively biased electrode,submerged in unmagnetized *** such an anodic structure,we have also investigated the condition under which the turbulence is *** of these structures,generated in front of a positively biased electrode,depends on multiple parameters such as the ratio of anode to cathode size,electrode separation,gas pressure,biasing configuration such as anode bias,cathode bias and grounding *** attempted to classify different anodic structures observed experimentally,as anode glow,fireball,anode spot,double layer and multiple double layers(MDLs)based on its physical *** these structures the present investigation is focused on *** number of layers,observed in MDLs varied from as high as six to as low as zero,by controlling the operating discharge parameters,*** were carried out using Langmuir *** analysis of floating potential fluctuations corresponds to a multiple anodic structure showed emergence of turbulence,at its critical stage,satisfying condition for self-organized criticality(SOC).This was identified with three slopes observed in the power spectrum,resembling the sand-pile ***,the GDP is completely different from that of the magnetically confined plasma,the nature of turbulence observed with SOC,is very similar to that observed in the scrape of layer of fusion ***,the present investigation could provide new approach to study turbulence of similar nature,under an experimental condition that is free from the complexities of complicated field geometries used in confinement devices.

关键词： glow discharge plasma anode structure multiple anodic double layer turbulence unmagnetized plasma fireball

MAXIMIZING RESTORATION SUCCESS WHEN THE GOOD GROUND IS GONE

在线全文

学校读者我要写书评

暂无评论

Journal of Green Building 2017年第3期12卷 115-123页

作者： alex Zimmerman the Erosion Control Technology Council

INTRODUCTION“The good ground is gone”often refers to the challenging nature of construction sites these *** on steeper slopes and within tighter boundaries while accelerat-ing construction schedules is adding to the challenge of construction *** the revegetation and restoration is unfortunately not planned or timed for successful long-term vegetation *** soil conditions are frequently overlooked and the timing necessary for seed germination,expression,and establishment are rarely factors in determining the schedule of seeding applications for optimum *** too often less than desired results or failure is the accepted *** will increase the future maintenance costs and encourage the repeated“finger pointing”while seeking to blame one cause or ***,this often-repeated process fails to address the fundamental causes and thereby rarely fixes the problems moving *** an effort to break out of this all too often repeated cycle,let’s break down the principle challenges and explore options for successful restoration of challenging ***,long-term revegetation starts with the *** quality soil that takes years to accumulate naturally,revegetation efforts regularly fail or the outcomes are less than *** construction,mining,and general land disturbing activities the soil will be degraded even while practicing the best topsoil harvesting and stock-piling management *** areas where vegetation is desired are essentially mineral without any organic matter or biological *** available,stockpiled topsoil will also degrade;the environment within the pile will create conditions that microbes,essential for plant health,will be negatively *** longer the stripped soils are stockpiled,the more living organisms are *** and even requirements for limiting the depth of the pile to reduce the loss of ben-eficial microbes is rarely possible given the tight bo

关键词： site restoration revegetation vertical task management stabilization methods soil conditions project scheduling erosion control