Journal of Research of the National Institute of Standards and Technology最新文献_第5页

DNA Origami Design: A How-To Tutorial. DNA折纸设计:如何教程

IF 1.3 4区工程技术

Journal of Research of the National Institute of Standards and Technology Pub Date : 2021-01-08 eCollection Date: 2021-01-01 DOI: 10.6028/jres.126.001

Jacob M Majikes, J Alexander Liddle

引用次数: 0

Fast Methods for Finding Multiple Effective Influencers in Real Networks. 在真实网络中寻找多个有效影响者的快速方法

IF 1.3 4区工程技术

Journal of Research of the National Institute of Standards and Technology Pub Date : 2020-12-31 eCollection Date: 2020-01-01 DOI: 10.6028/jres.125.036

Fern Y Hunt, Roldan Pozo

引用次数: 0

Fused Filament Fabrication Printer Modifed to Dispense Cement Paste for Concrete Additive Manufacturing Studies. 用于混凝土增材制造的水泥浆料熔丝制造打印机的改进研究

IF 1.3 4区工程技术

Journal of Research of the National Institute of Standards and Technology Pub Date : 2020-11-24 eCollection Date: 2020-01-01 DOI: 10.6028/jres.125.034

Scott Z Jones

{"title":"Fused Filament Fabrication Printer Modifed to Dispense Cement Paste for Concrete Additive Manufacturing Studies.","authors":"Scott Z Jones","doi":"10.6028/jres.125.034","DOIUrl":"10.6028/jres.125.034","url":null,"abstract":"Additive manufacturing (AM) with cement-based materials is an emerging technology that has the potential to revolutionize concrete construction. The placement process is quite complex, requiring suffcient flow properties as the material leaves the nozzle, and suffcient stiffening properties before the subsequent layer is placed. Precise control of material proportions and in-line monitoring of the time-dependent rheology are required to ensure the successful adoption of AM in the concrete construction community. To facilitate the study of the rheological properties of cementitious materials, as they pertain to AM, a commercial bench-top fused filament fabrication three-dimensional (3-D) printer was modifed to dispense cement paste mixtures. Modifcations included the design and assembly of a pumping system and software modifcations to the 3-D printer's firmware that were necessary to accommodate the new hardware. After assembly, a series of tests were conducted to verify machine movements and to calibrate the number of step pulses required per unit volume of extruded paste. The resulting software modifications and configuration files are publicly available.","PeriodicalId":54766,"journal":{"name":"Journal of Research of the National Institute of Standards and Technology","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2020-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11374360/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47377864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

An Initial Look at Federal Offices of Research and Technology Applications. 联邦研究和技术应用办公室初探

IF 1.3 4区工程技术

Journal of Research of the National Institute of Standards and Technology Pub Date : 2020-11-19 eCollection Date: 2020-01-01 DOI: 10.6028/jres.125.033

Nicole Gingrich, Michael Hall, Isaac Patterson

{"title":"An Initial Look at Federal Offices of Research and Technology Applications.","authors":"Nicole Gingrich, Michael Hall, Isaac Patterson","doi":"10.6028/jres.125.033","DOIUrl":"10.6028/jres.125.033","url":null,"abstract":"In Science-The Endless Frontier, Vannevar Bush wrote that reaping the potential benefits of science conducted at federal laboratories requires the discoveries made in the laboratories be transferred to society. In federal laboratories, Offices of Research and Technology Applications (ORTAs) are tasked with transferring laboratory-developed technologies to the market, allowing society to reap the benefits provided by scientific investments. In fiscal year 2016, the Technology Partnerships Office of the National Institute of Standards and Technology (NIST) conducted a first-of-its-kind survey of the ORTAs of more than 50 federal laboratories to obtain information on their organization and operation. We present descriptive analyses of the responses to this survey in two topical areas: organizational characteristics and technology transfer characteristics. We disaggregated the data across the dimension of budget size to describe similarities and differences in responses across the budget categories. Among the relationships we observed, we found that ORTAs with larger technology transfer budgets report higher frequencies of conducting internal technology transfer activities, such as patent prosecution (e.g., drafting patents, filing patent applications, and responding to actions from the patent office) and market analysis. Additionally, we provide context to the data by summarizing the relevant research on ORTAs at universities, and we present potential inferences that may be drawn from that body of research and applied to the data on ORTAs at federal laboratories.","PeriodicalId":54766,"journal":{"name":"Journal of Research of the National Institute of Standards and Technology","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2020-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10878689/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46559896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Parallel Generalized Real Symmetric-Definite Eigenvalue Problem. 并行广义实对称-确定特征值问题

IF 1.3 4区工程技术

Journal of Research of the National Institute of Standards and Technology Pub Date : 2020-11-06 eCollection Date: 2020-01-01 DOI: 10.6028/jres.125.032

James S Sims, María Bélen Ruiz

引用次数: 0

X-ray Computed Tomography Data of Additive Manufacturing Metrology Testbed (AMMT) Parts: "Overhang Part X4". 增材制造计量试验台(AMMT)零件的x射线计算机断层扫描数据:“悬垂部分X4”

IF 1.3 4区工程技术

Journal of Research of the National Institute of Standards and Technology Pub Date : 2020-10-01 eCollection Date: 2020-01-01 DOI: 10.6028/jres.125.031

Max Praniewicz, Brandon Lane, Felix Kim, Christopher Saldana

引用次数: 0

On The Quotient of a Centralized and a Non-centralized Complex Gaussian Random Variable 关于集中和非集中复高斯随机变量的商

IF 1.5 4区工程技术

Journal of Research of the National Institute of Standards and Technology Pub Date : 2020-09-23 DOI: 10.6028/JRES.125.030

D. Gu

{"title":"On The Quotient of a Centralized and a Non-centralized Complex Gaussian\u0000 Random Variable","authors":"D. Gu","doi":"10.6028/JRES.125.030","DOIUrl":"https://doi.org/10.6028/JRES.125.030","url":null,"abstract":"A detailed investigation of the quotient of two independent complex random variables is presented. The numerator has a zero mean, and the denominator has a non-zero mean. A normalization step is taken prior to the theoretical developments in order to simplify the formulation. Next, an indirect approach is taken to derive the statistics of the modulus and phase angle of the quotient. That in turn enables a straightforward extension of the statistical results to real and imaginary parts. After the normalization procedure, the probability density function of the quotient is found as a function of only the mean of the random variable that corresponds to the denominator term. Asymptotic analysis shows that the quotient closely resembles a normally-distributed complex random variable as the mean becomes large. In addition, the first and second moments, as well as the approximate of the second moment of the clipped random variable, are derived, which are closely related to practical applications in complex-signal processing such as microwave metrology of scattering-parameters. Tolerance intervals associated with the ratio of complex random variables are presented.","PeriodicalId":54766,"journal":{"name":"Journal of Research of the National Institute of Standards and Technology","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2020-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.6028/JRES.125.030","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49089256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Characterization of 3-Dimensional Printing and Casting Materials for use in Magnetic Resonance Imaging Phantoms at 3 T 用于3T磁共振成像显象的三维印刷和铸造材料的表征

IF 1.5 4区工程技术

Journal of Research of the National Institute of Standards and Technology Pub Date : 2020-09-15 DOI: 10.6028/jres.125.028

B. Yunker, K. Stupic, J. Wagner, S. Huddle, R. Shandas, R. Weir, S. Russek, K. Keenan

{"title":"Characterization of 3-Dimensional Printing and Casting Materials for use in Magnetic Resonance Imaging Phantoms at 3 T","authors":"B. Yunker, K. Stupic, J. Wagner, S. Huddle, R. Shandas, R. Weir, S. Russek, K. Keenan","doi":"10.6028/jres.125.028","DOIUrl":"https://doi.org/10.6028/jres.125.028","url":null,"abstract":"Imaging phantoms are used to calibrate and validate the performance of magnetic resonance imaging (MRI) systems. Many new materials have been developed for additive manufacturing (three-dimensional [3D] printing) processes that may be useful in the direct printing or casting of dimensionally accurate, anatomically accurate, patient-specific, and/or biomimetic MRI phantoms. The T1, T2, and T2* spin relaxation times of polymer samples were tested to discover materials for use as tissue mimics and structures in MRI phantoms. This study included a cohort of polymer compounds that was tested in cured form. The cohort consisted of 101 standardized polymer samples fabricated from: two-part silicones and polyurethanes used in commercial casting processes; one-part optically cured polyurethanes used in 3D printing; and fused deposition thermoplastics used in 3D printing. The testing was performed at 3 T using inversion recovery, spin echo, and gradient echo sequences for T1, T2, and T2*, respectively. T1, T2, and T2* values were plotted with error bars to allow the reader to assess how well a polymer matches a tissue for a specific application. A correlation was performed between T1, T2, T2* values and material density, elongation, tensile strength, and hardness. Two silicones, SI_XP-643 and SI_P-45, may be usable mimics for reported liver values; one silicone, SI_XP-643, may be a useful mimic for muscle; one silicone, SI_XP-738, may be a useful mimic for white matter; and four silicones, SI_P-15, SI_GI-1000, SI_GI-1040, and SI_GI-1110, may be usable mimics for spinal cord. Elongation correlated to T2 (p = 0.0007), tensile strength correlated to T1 (p = 0.002), T2 (p = 0.0003), and T2* (p = 0.003). The 80 samples not providing measurable signal with T1, T2, T2* relaxation values too short to measure with the standard sequences, may be useful for MRI-invisible fixturing and medical devices at 3 T.","PeriodicalId":54766,"journal":{"name":"Journal of Research of the National Institute of Standards and Technology","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2020-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43616485","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

Characterization of 3-Dimensional Printing and Casting Materials for use in Computed Tomography and X-ray Imaging Phantoms 用于计算机断层扫描和x射线成像的三维打印和铸造材料的特性

IF 1.5 4区工程技术

Journal of Research of the National Institute of Standards and Technology Pub Date : 2020-09-15 DOI: 10.6028/jres.125.029

B. Yunker, A. Holmgren, K. Stupic, J. Wagner, S. Huddle, R. Shandas, R. Weir, K. Keenan, E. Garboczi, S. Russek

引用次数: 2

Process Monitoring Dataset from the Additive Manufacturing Metrology Testbed (AMMT): Overhang Part X4. 增材制造计量试验台（AMMT）的过程监测数据集：悬置部件X4

IF 1.3 4区工程技术

Journal of Research of the National Institute of Standards and Technology Pub Date : 2020-09-03 eCollection Date: 2020-01-01 DOI: 10.6028/jres.125.027

Brandon Lane, Ho Yeung

引用次数: 0