808 research outputs found
Spinning Tubes: An Authentic Research Experience in a Three-hour Laboratory
We discuss a three-hour laboratory that is a microcosm of physics research, starting with the discovery of an intriguing phenomenon, and including participation in “research conferences” and the interplay of theory and experiment. Students are given a small segment of PVC pipe marked at opposite ends with different symbols and asked to observe what happens when the pipe is placed on a horizontal surface and one end is pushed downward by a finger to initiate a rotation. Most students immediately recognize that the symbol at one end is visible while the other is not, and set about trying to understand why. Students initially work in pairs and are provided with opportunities to request equipment from a “granting agency” and conferences and collaborations are encouraged. Students are quickly caught up in their search for explanations, usually culminating in a full-class effort with significant contributions coming from all students
A market inventory of construction wood for residential building in Europe – in the light of the Green Deal and new circular economy ambitions
Wood is an energy efficient, low carbon construction material that if carefully managed can contribute significantly to European climate policy goals in urban environments. The aim of this study is to assess the current construction wood use intensity  the ratio of apparent national consumption of wood for construction (in m3) to the useful floor area of newly finished dwellings (in m2)  and to identify when and where additional policy measures are required. Results show that Cyprus/Malta have the smallest use with a ratio of 0.01, Estonia/Romania the greatest use with a ratio of 0.32. The need for additional policy measures, was assessed using the Boston Consultancy Group (BCG) matrix with four product development phases, based on the aforementioned ratio versus future growth. Six, twelve, eight and two countries are in the “Introduction“, “Growth”, ”Maturity” and “Decline” phases, respectively. At the EU level, the European Commission should consider introducing a Renewable Material Directive, in which a Non-biogenic Material Comparator shows the average GHG substitution effect of using wood for construction. At the international level, a new harvested wood product (HWP) category in the IPCC Guidelines is recommended for construction wood with a longer lifespan than the current HWP categories
Metabolic Energy Generation In Hydrogenosomes Of The Anaerobic Fungus Neocallimastix - Evidence For A Functional-relationship With Mitochondria
Metabolic Energy Generation In Hydrogenosomes Of The Anaerobic Fungus Neocallimastix - Evidence For A Functional-relationship With Mitochondria
New Types of Thermodynamics from -Dimensional Black Holes
For normal thermodynamic systems superadditivity , homogeneity \H and
concavity \C of the entropy hold, whereas for -dimensional black holes
the latter two properties are violated. We show that -dimensional black
holes exhibit qualitatively new types of thermodynamic behaviour, discussed
here for the first time, in which \C always holds, \H is always violated
and may or may not be violated, depending of the magnitude of the black
hole mass. Hence it is now seen that neither superadditivity nor concavity
encapsulate the meaning of the second law in all situations.Comment: WATPHYS-TH93/05, Latex, 10 pgs. 1 figure (available on request), to
appear in Class. Quant. Gra
Developing and Deploying Security Applications for In-Vehicle Networks
Radiological material transportation is primarily facilitated by heavy-duty
on-road vehicles. Modern vehicles have dozens of electronic control units or
ECUs, which are small, embedded computers that communicate with sensors and
each other for vehicle functionality. ECUs use a standardized network
architecture--Controller Area Network or CAN--which presents grave security
concerns that have been exploited by researchers and hackers alike. For
instance, ECUs can be impersonated by adversaries who have infiltrated an
automotive CAN and disable or invoke unintended vehicle functions such as
brakes, acceleration, or safety mechanisms. Further, the quality of security
approaches varies wildly between manufacturers. Thus, research and development
of after-market security solutions have grown remarkably in recent years. Many
researchers are exploring deployable intrusion detection and prevention
mechanisms using machine learning and data science techniques. However, there
is a gap between developing security system algorithms and deploying prototype
security appliances in-vehicle. In this paper, we, a research team at Oak Ridge
National Laboratory working in this space, highlight challenges in the
development pipeline, and provide techniques to standardize methodology and
overcome technological hurdles.Comment: 10 pages, PATRAM 2
Gravitation and Cosmology in Generalized (1+1)-dimensional dilaton gravity
The actions of the ``'' and string-inspired theories of gravity in (1+1)
dimensions are generalized into one single action which is characterized by two
functions. We discuss differing interpretations of the matter stress-energy
tensor, and show how two such different interpretations can yield two different
sets of field equations from this action. The weak-field approximation,
post-Newtonian expansion, hydrostatic equilibrium state of star and
two-dimensional cosmology are studied separately by using the two sets of field
equations. Some properties in the ``'' and string-inspired theories are
shown to be generic in the theory induced by the generalized action.Comment: 34 page
Theory of Unconventional Spin Density Wave: A Possible Mechanism of the Micromagnetism in U-based Heavy Fermion Compounds
We propose a novel spin density wave (SDW) state as a possible mechanism of
the anomalous antiferromagnetism, so-called the micromagnetism, in URu_2Si_2
below 17.5[K]. In this new SDW, the electron-hole pair amplitude changes its
sign in the momentum space as in the case of the unconventional
superconductivity. It is shown that this state can be realized in an extended
Hubbard model within the mean field theory. We also examine some characteristic
properties of this SDW to compare with the experimental results. All these
properties well explain the unsolved problem of the micromagnetism.Comment: REVTeX v3.1, 4 pages, 5 figure
Patient satisfaction and amenorrhea rate after endometrial ablation by ThermaChoice III or NovaSure: a retrospective cohort study
Heavy menstrual bleeding poses an important health problem, which can be managed, besides other treatments, with endometrial ablation. Nowadays, the bipolar radio frequency device (NovaSure) is the most commonly used device for endometrial ablation, followed by the thermal balloon device (ThermaChoice III). Thus far, studies looking at treatment outcomes have mainly been done comparing NovaSure with the older ThermaChoice (I–II) devices. The aim of this study is to compare the effectiveness of the improved ThermaChoice III with NovaSure. Patients treated with ThermaChoice III at the Ziekenhuisgroep Twente hospital and NovaSure at the Medisch Spectrum Twente hospital were included in the study. The primary outcome measure was patient satisfaction after treatment, measured by the condition-specific menorrhagia multi-attribute scale (MMAS). The secondary outcome measure was effectiveness of the treatment, measured by the amenorrhea rate and the hysterectomy rate. Five hundred fourteen patients were included in this study; of these, 216 patients were treated with ThermaChoice III and 289 patients with NovaSure. The score on the condition-specific MMAS was high for both groups, without a significant difference between the groups (88.8 vs 86.5, p = 0.183). The amenorrhea rate was significantly higher in the NovaSure group (45 vs 27 %, p = 0.001). The hysterectomy rate was slightly higher in the ThermaChoice III group, without a significant difference between the groups (19 compared to 13 %, p = 0.066). Patient satisfaction is comparable in patients treated with ThermaChoice III or NovaSure. However, NovaSure endometrial ablation leads to a significantly higher amenorrhea rat
High intensity interval training improves liver and adipose tissue insulin sensitivity
Objective: Endurance exercise training reduces insulin resistance, adipose tissue inflammation and non-alcoholic fatty liver disease (NAFLD), an effect often associated with modest weight loss. Recent studies have indicated that high-intensity interval training (HIIT) lowers blood glucose in individuals with type 2 diabetes independently of weight loss; however, the organs affected and mechanisms mediating the glucose lowering effects are not known. Intense exercise increases phosphorylation and inhibition of acetyl-CoA carboxylase (ACC) by AMP-activated protein kinase (AMPK) in muscle, adipose tissue and liver. AMPK and ACC are key enzymes regulating fatty acid metabolism, liver fat content, adipose tissue inflammation and insulin sensitivity but the importance of this pathway in regulating insulin sensitivity with HIIT is unknown. Methods: In the current study, the effects of 6 weeks of HIIT were examined using obese mice with serine–alanine knock-in mutations on the AMPK phosphorylation sites of ACC1 and ACC2 (AccDKI) or wild-type (WT) controls. Results: HIIT lowered blood glucose and increased exercise capacity, food intake, basal activity levels, carbohydrate oxidation and liver and adipose tissue insulin sensitivity in HFD-fed WT and AccDKI mice. These changes occurred independently of weight loss or reductions in adiposity, inflammation and liver lipid content. Conclusions: These data indicate that HIIT lowers blood glucose levels by improving adipose and liver insulin sensitivity independently of changes in adiposity, adipose tissue inflammation, liver lipid content or AMPK phosphorylation of ACC
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