Core drill's bit is replaceable without withdrawal of drill stem - A concept

Drill bit is divided into several sectors. When collapsed, the outside diameter is forced down the drill stem, when it reaches bottom the sectors are forced outward and form a cutting bit. A dulled bit is retracted by reversal of this procedure

Torsionally rigid and thermally stable boom

Design of rigid thermally stable beryllium copper extendible boom for space application

Tale Of A Non-Interacting Additive In A Lithium-Ion Electrolyte: Effect On Ionic Speciation And Electrochemical Properties

New lithium electrolytes compatible with high energy density cells are critical for lithium metal battery applications, but dendrite formation associated with the use of dilute organic electrolytes complicates their realization. High-concentration electrolytes mitigate some of the issues of the electrolytes but introduce additional problems, such as low conductivity and high cost. Hence, pseudo-concentrated electrolytes, wherein a co-solvent is added to a dilute electrolyte, have been presented as a possible alternative to both dilute and concentrated electrolytes. However, the effect that the co-solvent has on the electrolyte properties at both macroscopic and microscopic levels is unknown. Here, a study of the structure and electrochemical properties of two electrolytes as a function of co-solvent concentration is presented using an array of spectroscopies (FTIR, ATR-FTIR, and nuclear magnetic resonance) and computational methods (density functional theory calculations). The chosen electrolytes comprised two different lithium salts (LiPF6 and LiTFSI) in a mixture of dimethyl carbonate (DMC) with 1,1,1,3,3-pentafluorobutane (PFB) as the co-solvent. Our results show that in the case of the LiPF6/DMC electrolyte, the addition of a co-solvent (PFB) with a larger dielectric constant results in the strengthening of the lithium-anion interaction and the formation of aggregate species since PFB does not interact with the anion. Conversely, in the LiTFSI/DMC electrolyte, the co-solvent appears to interact with the anion via hydrogen bonds, which leads to the dissociation of contact ion pairs. The change in ionic speciation of the electrolytes upon addition of PFB provides a reasonable framework to explain the different trends in both the bulk and interfacial macroscopic properties, such as conductivity, viscosity, and electrochemical stability. Overall, our findings demonstrate that the interactions between the anion and the co-solvent must be taken into consideration when adding a co-solvent because they play a major role in determining the final electrolyte properties

The Effects of Grazing Cover Crops on Animal Performance and Soybean Production

Grazing cover crops has the potential to offset costs incurred with cover crop establishment, thus incentivizing management adoption. Information regarding cover crop species in combination with grazing and their subsequent effects on soybean production is limited. A field trial was conducted in Newton, MS from 2019 to 2021 to assess these effects. Cover crop treatments included oats (O), O + crimson clover (OC), and OC + radish (OCR) were applied in a randomized complete block design with three replications. Cover crops differed in nutritive analysis; O had significantly lower mean CP, but greater total daily nutrients (TDN). Weaned beef steers grazing cover crops had lower ADG in the OCR treatment (3.03 lb hd-1 d-1), compared to O (3.52 lb hd-1 d-1) and OC (3.55 lb hd-1 d-1). No significant difference was observed in soybean grain yield between cover crop treatments. Mean yields were 51.1, 46.1, and 38.7 bu ac-1 for the O, OC, and OCR treatments, respectively. Total net returns for grazing plus soybean production were significantly lower in the OCR ($817.51 ac-1), compared to the O ($1,107.03 ac-1) and OC ($1,071.15 ac-1) treatments. These returns suggest that grazing provides an added value to cover crop establishment and provides incentives for increased revenue for producers willing to combine livestock and row crop enterprises

Chemical and Thermal Analysis

Work has included significant research in several areas aimed at further clarification of the aging and chemical failure mechanism of thermoplastics (PVDF or Tefzel) for pipes. Among the areas investigated were the crystallinity changes associated with both the Coflon and Tefzel after various simulated environmental exposures using X-Ray diffraction analysis. We have found that significant changes in polymer crystallinity levels occur as a function of the exposures. These crystallinity changes may have important consequences on the fracture, fatigue, tensile, and chemical resistance of the materials. We have also noted changes in the molecular weight distribution of the Coflon material using a dual detector Gel Permeation Analysis. Again these changes may result in variation in the mechanical and chemical properties in the material. We conducted numerous analytical studies with methods including X-Ray Diffraction, Gel Permeation Chromatography, Fourier Transform Infrared Spectroscopy, Thermogravimetric Analysis, and Differential Scanning Calorimetry. We investigated a number of aged samples of both Tefzel and Coflon that were forwarded from MERL. Pressurized tests were performed in a modified Fluid G, which we will call G2. In this case the ethylene diamine concentration was increased to 3 percent in methanol. Coflon pipe sections and powdered Coflon were exposed in pressure cells at 1700 psi at three separate test temperatures, 70 C, 110 C, and 130 C. The primary purpose of the pressure tests in Fluid G2 was to further elucidate the aging mechanism of PVDF degradation

Mechanical Effects of Rice Hush Ash in Ultra-High Performance Concretes: A Matrix Study,

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/84784/1/stults-RHA-2009.pd

Usability and Psychosocial Impact of Decision Support to Increase Sexual Health Education in American Indian and Alaska Native Communities

Despite sexual and reproductive health disparities, few evidence-based sexual health education programs exist for American Indian/Alaska Native (AI/AN) youth, with even fewer tools available to assist AI/AN communities in adopting, implementing, and maintaining such programs. iCHAMPSS (Choosing And Maintaining effective Programs for Sex education in Schools) is a theory- and web-based decision-support-system designed to address dissemination barriers and increase the reach and fidelity of evidence-based programs (EBPs), specifically sexual health education programs. To investigate the potential of iCHAMPSS in AI/AN communities, we pilot-tested iCHAMPSS with adult stakeholders (N = 36) from agencies across the country that serve AI/AN communities. Stakeholders were recruited to review selected iCHAMPSS tools over two weeks in spring 2016. Pre- and post-surveys were administered to assess usability constructs, short-term psychosocial outcomes, and perceived feasibility. Data were analyzed using descriptive and non-parametric statistics. iCHAMPSS was perceived as acceptable, easy to use, credible, appealing, more helpful than current resources, and impactful of EBP adoption, implementation, and maintenance. Conversely, using iCHAMPSS significantly increased participants’ perceived barriers to adopting an EBP (p = 0.01). Overall, AI/AN stakeholders responded positively to iCHAMPSS, indicating the potential for adaptation to support the dissemination and implementation of evidence-based sexual health education in AI/AN communities

Associations for Citizen Science: Regional Knowledge, Global Collaboration

Since 2012, three organizations advancing the work of citizen science practitioners have arisen in different regions: The primarily US-based but globally open Citizen Science Association (CSA), the European Citizen Science Association (ECSA), and the Australian Citizen Science Association (ACSA). These associations are moving rapidly to establish themselves and to develop inter-association collaborations. We consider the factors driving this emergence and the significance of this trend for citizen science as a field of practice, as an area of scholarship, and for the culture of scientific research itself

Healthy & Empowered Youth: A Positive Youth Development Program for Native Youth

Introduction: During 2010–2012, Oregon Health & Science University’s Prevention Research Center, a Northwest Tribe, and the Northwest Portland Area Indian Health Board, collaborated to evaluate the Healthy & Empowered Youth Project, a school- and community-based positive youth development program for American Indian and Alaska Native high school students. Methods: The Native STAND (Students Together Against Negative Decisions) curriculum was enhanced with hands-on learning activities in media design to engage students in sexual and reproductive health topics covered by the curriculum. Guest speakers, field trips, and extracurricular activities were added to provide academic enrichment, engage students in cultural activities, and offer opportunities for career development. Students completed comprehensive pre- and postsurveys, and the authors conducted focus groups and key informant interviews with students and teachers. Data analysis was conducted during 2013–2014. Results: Survey findings demonstrated improvements in student leadership and achievement, physical and mental health, and protective sexual health behaviors. The percentage of female teens reporting use of a condom the last time they had sex increased from 17% to 30%, and those who reported ever having been tested for sexually transmitted illnesses doubled from 12% to 24%. Focus group and interview findings indicated similar improvements in student self-esteem, life skills, health behavior, and engagement in community. Conclusions: The Healthy & Empowered Youth Project educated and empowered Native high school students on a variety of sensitive health topics. The media enhancements were central to the program’s success, reinforcing and personalizing classroom lessons and generating health-related videos and posters that resonated with family and friends