Hasil untuk "Engineering"

C. Crowe, D. Elger

S. Sandler

A. Bourgoyne, M. Chenevert, K. Millheim et al.

An industry and academic standard, Applied Drilling Engineering presents engineering science fundamentals as well as examples of engineering applications involving those fundamentals. Two appendices are included, along with numerous examples. Answers are included for every end-of-chapter question. Solutions to Chapter 8 (http://go.spe.org/ADEsolutions)

F. L. Matthews, R. Rawlings

N. Nise

Deborah J. Mayhew

N. Maluf

S. Campbell

Shoufeng Yang, K. Leong, Z. Du et al.

Tissue engineering (TE) is an important emerging area in biomedical engineering for creating biological alternatives for harvested tissues, implants, and prostheses. In TE, a highly porous artificial extracellular matrix or scaffold is required to accommodate mammalian cells and guide their growth and tissue regeneration in three-dimension (3D). However, existing 3D scaffolds for TE proved less than ideal for actual applications because they lack mechanical strength, interconnected channels, and controlled porosity or pores distribution. In this paper, the authors review the application and advancement of rapid prototyping (RP) techniques in the design and creation of synthetic scaffolds for use in TE. We also review the advantages and benefits, and limitations and shortcomings of current RP techniques as well as the future direction of RP development in TE scaffold fabrication.

Megan Meece

U. Leonhardt, T. Philbin

In electrical engineering metamaterials have been developed that offer unprecedented control over electromagnetic fields. Here, we show that general relativity provides the theoretical tools for designing devices made of such versatile materials. Given a desired device function, the theory describes the electromagnetic properties that turn this function into fact. We consider media that facilitate space-time transformations and include negative refraction. Our theory unifies the concepts operating behind the scenes of perfect invisibility devices, perfect lenses, the optical Aharonov–Bohm effect and electromagnetic analogues of the event horizon, and may lead to further applications.

LI Wenwen, YUAN Ruiming, ZHOU Hui et al.

Aiming at the influence of the fast, large range and random change of dynamic load current on the electricity metering, this paper firstly establishes a non-stationary random process modulation model and bimodal modulation model for complex dynamic power signal, and derives model parameters such as quasi-steady term and dynamic term amplitude. Based on the first spline least squares empirical mode decomposition (FS-EMD) method, a parameter extraction method for the amplitude model of quasi-steady and dynamic terms is proposed, the correctness of the method is demonstrated through the decomposition of power signals from electrified railway traction substations and arc furnaces. By mapping the amplitude domain model parameters, the important characteristic parameters in amplitude domain representing complex dynamic electric energy signals are constructed, and four important features are extracted. Finally, the dynamic error tests conducted on electricity meters reveal that the four significant parameters identified herein act as critical factors triggering the meter's performance to exceed tolerance thresholds.

J. Nichol, A. Khademhosseini

A. Hastings, J. E. Byers, J. Crooks et al.

J. Mitchell, J. C. Santamarina

Elinor Randi Schoenfeld, Tracy Trimboli, Kaylyn Schwartz et al.

By 2050, most adults aged 65 and older in the United States will want to age independently at home, a goal that will strain healthcare resources. Adults aged 50 and older (N = 112) were recruited for study participation between 2018 and 2022. They completed surveys and participated in discussion sessions to explore their needs and opinions regarding smart home sensors. Survey results indicated that older adults’ comfort with smart home sensors increased with their perceived need for monitoring when home alone (OR = 1.46; <i>p</i> = 0.012) or sick/recovering from an illness (OR = 2.21; <i>p</i> < 0.001). When sick compared to when healthy, individuals were 2.65 times more likely to prefer installing multiple sensors in the living room, 1.75 times more likely in the kitchen, 3.66 times more likely in the bedroom, and 3.41 times more likely in the bathroom (<i>p</i> < 0.05). Regarding data sharing, participants were most willing to share information with healthcare providers and family members on a regular basis (80 and 81%, respectively) and 71% on a regular basis or when sick/recovering. Comfort with data sharing with professional caregivers (OR = 1.67; <i>p</i> = 0.0017) and monitoring companies (OR = 1.34; <i>p</i> = 0.030) significantly increased when sick/recovering. Discussion sessions highlighted overwhelming concerns about personal security/privacy, loss of independence, and ethical issues in data collection. Participants emphasized the need for new systems to be flexible, cost-effective, user-friendly, and respectful of user autonomy, accommodating diverse life stages, comfort levels, home environments, income levels, and support structures. Insights are now informing sensor data collection in our model home. Study findings underscore the importance of involving potential users in technology development to create effective and acceptable solutions for aging in place.

W. Furian, T. Sauter

<p>This study investigates simulated glacial lake outburst floods (GLOFs) at five glacial lakes in the Everest region of Nepal using the three-dimensional model OpenFOAM. It presents the evolution of GLOF characteristics in the 21st century considering different moraine breach scenarios and two Shared Socioeconomic Pathways scenarios. The results demonstrate that in low-magnitude scenarios, the five lakes generate GLOFs that inundate between 0.35 and 2.23 km<span class="inline-formula">²</span> of agricultural land with an average water depth of 0.9 to 3.58 m. These GLOFs reach distances of 59 to 84 km, affect 30 to 88 km of roads or trails, and inundate 183 to 1699 buildings with 1.2 to 4.9 m of water. In higher scenarios, GLOFs can extend over 100 km and also affect larger settlements in the foothills. Between 80 and 100 km of roads, 735 to 1989 houses and 0.85 to 3.52 km<span class="inline-formula">²</span> of agricultural land could be inundated, with average water depths of up to 10 m. The high precision of the 3D flood modeling, with detailed simulations of turbulence and viscosity, provides valuable insights into 21st-century GLOF evolution, supporting more accurate risk assessments and effective adaptation strategies.</p>

Zabin K. Bagewadi, Gouri H. Illanad, T. M. Yunus Khan et al.

Abstract The current investigation reports anti-cancer, antioxidant and antibacterial potential of L-Glutaminase (Streptomyces roseolus strain ZKB1) and L-Glutaminase capped nanoparticles. The highest L-Glutaminase production of 9.57 U/mL was achieved on the 4th day of fermentation when L-Glutamine was used as the sole carbon and nitrogen source. Enhanced recycling stability was observed after 6 cycles using L-Glutaminase immobilized in 3% agar and agarose matrices. Free and immobilized L- Glutaminase showed K m of 13.89 ± 0.8 and 7.13 ± 0.3 mM and V max of 18.40 ± 1.5 and 24.21 ± 1.7 U/mg respectively. L- Glutaminase capped silver (AgNP) and zinc oxide (ZnONP) nanoparticles were synthesized and structurally characterized using UV visible spectroscopy, FTIR, SEM–EDS, XRD and AFM. L- Glutaminase capped AgNP and ZnONP exhibited good thermal stability with five and three stages weight loss pattern respectively based on TGA. L-Glutaminase capped AgNP exhibited highest inhibitory activity against B. subtilis (45 $$\pm$$ ± 0.5 mm) and E. coli (33 $$\pm$$ ± 0.8 mm) whereas, L-Glutaminase capped ZnONP demonstrated highest inhibition against E. coli (30 $$\pm$$ ± 0.3 mm) and B. cereus (25 $$\pm$$ ± 0.5 mm). Increased nanoparticles concentration exhibited increased inhibitory potential as compared to wild L-Glutaminase and lowest MIC of 0.09 µg/mL was exhibited against B. cereus. L-Glutaminase capped nanoparticles demonstrated significant antioxidant properties through in-vitro ABTS and DPPH radical scavenging assays in a dosage-dependent manner. L-Glutaminase and capped AgNP and ZnONP, demonstrated pronounced cell cytotoxicity against MCF-7 cancerous cell line with 57.17 µg/mL, 8.13 µg/mL and 28.31 µg/mL IC50 values respectively, suggesting promising properties as anticancer agents in enzyme-based therapy. The results reveal promising biological activities with potential applications in healthcare sector. Graphical Abstract

Ziqian Wang, Yuhan Qian, Tengteng Sun et al.

Ti-modified AlCuMg alloys have demonstrated great potential in improving the printability and mechanical properties of conventional Al alloys processed by laser powder-bed fusion (LPBF). However, an effective material design method, which considers processing parameters and solidification microstructure, is currently absent. Accordingly, the present work proposed a comprehensive model with which the formation of hot-tearing cracks and lack-of-fusion pores could be more efficiently predicted. The hot-tearing factor was an assistant in the tailoring of crack-free Ti-modified AlCuMg alloys, while the lack-of-fusion factor suggested a volumetric energy density for better printability. This hot-tearing factor could also serve as the supplementary method for evaluating the crack susceptibility of AlCuMg alloys. The microstructure evolution and mechanical properties were also investigated to achieve an optimal processing window for these alloys, which could satisfy the dual requirements of higher mechanical properties and better formability. It was believed that this comprehensive model would facilitate the tailoring of crack-free AlCuMg alloys and the optimisation of processing parameters in a time-efficient manner with high precision.

Robin Kimmel, Judith Michael, Andreas Wortmann et al.

Digital twins promise a better understanding and use of complex systems. To this end, they represent these systems at their runtime and may interact with them to control their processes. Software engineering is a wicked challenge in which stakeholders from many domains collaborate to produce software artifacts together. In the presence of skilled software engineer shortage, our vision is to leverage DTs as means for better rep- resenting, understanding, and optimizing software engineering processes to (i) enable software experts making the best use of their time and (ii) support domain experts in producing high-quality software. This paper outlines why this would be beneficial, what such a digital twin could look like, and what is missing for realizing and deploying software engineering digital twins.