Miracle-dz/UniFAR-FTUs huggingface dataset:
Noise Consideration of the Variable Capacitance Parametric Amplifier

This paper describes a model of the variable capacitance diode in which the spreading resistance is considered as the source of amplifier noise. Gain and noise figure calculations are made for this model and experimental results obtained at 5.84 kmc while pumping at 11.7 kmc are presented for gallium arsenide, silicon and germanium diodes. The qauntity 1/ωC0Rss defined as a quality factor" where Rs, is the spreading resistance and C0 is the static capacitance at zero bias point. Computations of minimum noise figure, optimum load admittance, optimum pumping factor, are all given in terms of the parameter ωC0Rs. The essential differences between single- and double-sideband reception are discussed. Over a range of sufficiently large values of the parameter ωC0Rs, there is a reasonable correlation of the theory developed with the measurements performed on most of the diodes. In the range of relatively small values of ωC0Rs, the model proves inadequate to describe some diodes properly and suggests the need for introducing extra noise sources. These noise sources are also discussed. Of the experimental data obtained thus far, the best result has been with a gallium arsenide diode which yields a 0.9 db double-sideband noise figure and, equivalently, 3.9 db for single-sideband operation with 16 db gain and 25 mc of single-sideband frequency bandwidth.
A Magnetic Amplifier for Radio Telephony

A magnetic amplifying device is described for permitting the control of radio frequency currents by varying the saturation of the iron core of an inductance included in the radio frequency circuit. The arrangement of windings of the amplifier is such that the controlling winding has no radio frequency E. M. F. induced in it, nor does it induce currents in the radio frequency coils. Various arrangements of this amplifier in connection with a solid steel rotor, radio frequency alternator are shown, notably those in series with the alternator and those in parallel. "Short-circuiting" condensers are connected to each of the radio frequency coils. A shunt condenser across both coils and their "short-circuiting" condensers increases the sensitiveness for reasons which are given. Another condenser inserted in series with the entire amplifier is employed to obtain linear proportionality of amplification and increased sensitiveness. The ratio of amplification is found to be proportional to the ratio of the frequency of the radio current to that of the controlling current. The control of the output of a 75 K. W. alternator of radio frequency for telephonic purposes is then shown by oscillograms to be accurate, and the numerical characteristics of alternator and amplifier separately and in combination are given.
Heat Losses in the Conductors of Alternating-Current Machines

The principal object of this paper is to show how hyperbolic functions of complex angles may be applied to the solution of the problem of heat losses in rectangular conductors that are embedded in open slots. A certain knowledge of the functions themselves is presupposed. Inasmuch, however, as they are handled like trigometric functions of real angles-except in regard to the plus and minus signs-it is a simple matter to acquire the requisite technical skill to use them. The hyperbolic function of a complex angle, consisting as it does of a real and an imaginary part, may represent a vector-the real part being the component of the vector along the horizontal, and the imaginary part, component along the vertical. Thus, for example, A sinh (x + j x) represents a vector just as A e j θ A/θ, A (cos θ + j sin θ) represent vectors. Considerable experience has shown that the vector method for handling a-c. problems is much superior to the original method in which simple trigonometric functions were used. With this lesson before us, it should require but little contact with the problem at hand to demonstrate the superiority of the vector method, even though it employs the possibly unfamiliar hyperbolic quantities. These hyperbolic vectors have been used for a number of years in the analysis of problems involving a-c. circuits, which have distributed inductance and capacitance, and have proved their usefulness.
The Constants in the Equation for Atmospheric Refractive Index at Radio Frequencies

Recent improvements in microwave techniques have resulted in precise measurements which indicate that the conventional constants K1 = 79°K/mb and K2′=4,800°K in the expression for the refractivity of air, N=(n-1) 106=[K1/T](p+ K2'e/T) should be revised. Various laboratories appear to have arrived at this conclusion independently. In much of radio propagation work the absolute value of the refractive index of the atmosphere is of small moment. However, in some work it is important and it seems highly desirable to decide upon a particular set of constants. Through consideration of the various recent experiments this paper arrives at a relation 77.6 e N = ~ p + 4,810-T T where p=total pressure in millibars e=partial pressure of water vapor in millibars T=absolute temperature=°C+273 This expression is considered to be good to 0.5 per cent in N for frequencies up to 30,000 mc and normally encountered ranges of temperatures, pressure and humidity.
Experience and recent developments in central station protective features

The protective features described in this paper are some of those now in use on the system of the Public Service Electric Co. which serves a population of about 2,200,000. The most interesting protective devices and schemes discussed in this paper are as follows: Aluminum cell arresters; arcing ground suppressor; faulty cable localizer; cable testing; high potential and high frequency testing; generator bus connection scheme; exciter connection scheme; reactors; relays; multi-recorder; insulation resistance recorder; air washers; resistance bulbs and thermo-couples; dampers on air blast transformers; coherer alarm devices; potential indicating devices.
“Doubtful accepting”: A grounded theory study of living with cardiac resynchronization therapy

Heart failure is associated with low quality of life and a high mortality rate. There is limited information about patients' experiences of living with cardiac resynchronization therapy (CRT). In the present study, we sought to explore the process of living with CRT defibrillator. This qualitative study was completed from December 2014 to April 2016 using a grounded theory approach. Twenty semistructured interviews were held with 17 patients with heart failure. Data analysis was done via a previously-published approach. The core category of the process of living with the device is "doubtful accepting". This process includes three sequential phases: losing integrity, attempting to cope with the device, and coexisting. The process takes place in a context of barriers and facilitators, and results in a wide spectrum of outcomes, from frustration to empowerment. Nurses' awareness of this process can help them provide higher quality care, strengthen facilitators and reduce barriers to the process, and enable patients to effectively use coping strategies.
A New Wide-Range, High-Frequency Oscillator

A new tube is described which is fundamentally a Barkhausen oscillator with an electron gun and a cavity resonator. The tube is inherently inefficient, but is capable of tuning over extremely wide frequency ranges. For one single tube, for instance, the wavelength ranges from 4.5 to 12 cm and the output power from 0.1 to 1.0 watt.
Protein kinase CK2 modulation of pyruvate kinase M isoforms augments the Warburg effect in cancer cells

Protein kinase CK2 is active in cancer cells. Previously, we reported that increased CK2 activity could induce epithelial mesenchymal transition of cancer cells. CK2 also induced epithelial mesenchymal transition in colon cancer cell lines such as HT29 and SW620, and the transitioned cells (CK2α cells) became more proliferative than the controls. We assumed that CK2 could affect cancer cell growth by modulating their energy metabolism. Here, we examined the molecular effects of CK2 on the glucose metabolism of cancer cells. We found that CK2α cells consumed more glucose and produced more lactate than control cells did. An XF glycolysis stress test showed that aerobic glycolysis was augmented up to the cancer cell’s maximal glycolytic capacity in CK2α cells. Molecular analysis revealed that pyruvate kinase M1 was downregulated and pyruvate kinase M2 was nuclear localized in CK2α cells. Consequently, the expression and activity of lactate dehydrogenase A (LDHA) were upregulated. Treatment with FX11—a specific LDHA inhibitor—or clustered regularly interspaced short palindromic repeats (CRISPR)‐mediated knockout of LDHA inhibited the CK2‐driven proliferation of cancer cells. We conclude that CK2 augments the Warburg effect, resulting in increased proliferation of cancer cells.
Clock tree distribution

The semiconductor industry is moving toward submicron and deep submicron (0.5 μm and below) technologies. As the chip size keeps decreasing, the chip capacity keeps increasing. New challenges are appearing on high speed ASIC (Application Specified Integrated Circuit) design. Building a balanced clock tree is now essential for the success of any advanced VLSI (Very Large Scale Integration) design. The interconnect wire delay is as important as the logic gate delay.
The Moon as Source for G/T Measurements

For large-aperture antennas, it is customary to utilize radio stars in order to determine the receiving gain to temperature ratio. In the case of small-aperture antennas, which not only have reduced gain but usually higher system noise temperature as well, the y factors obtained from the radio star measurements are so small that the measurement error is intolerable. The moon, on the other hand, provides a power flux density higher by at least one order of magnitude compared to the strongest radio star, and the resulting y factors are usable. G/T ratios determined from moon measurements agree well with expected values.
The immediate and 1-week effects of mid-thoracic thrust manipulation on lower extremity passive range of motion

ABSTRACT Background Research suggests that spinal manipulation may effect motion. Less clear is whether this effect is limited to localized responses or may involve generalizable changes. Objective: To determine whether Mid-thoracic manipulation (MTM) would result in a significant change in the lower extremity passive straight leg raise (PSLR) range of motion immediately and after 1 week. Methods: Twenty-three healthy subjects were randomly assigned in a double-blinded study. An experimental group received MTM and a control group received a sham intervention. PSLR measurements were taken prior to, immediately after, and one week after the intervention. Results: Mixed model repeated measure analysis of variance was used to determine that there was a significant interaction between MTM and time (F(2, 21) = 3.84, p < 0.05). Post hoc tests revealed a significant difference between the pretest to immediate posttest values (p < 0.05, SE = 1.47). PSLR in the MTM group increased 10.3° while the sham group increased 1.9°. Difference was non-significant between pretest and 1-week follow-up (p = 0.129, SE = 2.46). Conclusions: MTM may immediately increase lower extremity passive range of motion, but the effect was lost by the 1-week follow-up. This supports evolving research suggesting that spinal manipulation may have a generalized but transient physiological effect.
Compensation of an error-sampled system by a multirate controller

A special type of multirate sampled-data system, i.e., a system which contains switches operating with different sampling periods, is discussed in this paper. It is shown, after a brief outline of the multirate mathematics, how a multirate controller can be designed to compensate an error-sampled feedback system. Such a controller can be realized as a pulsed network which in response to input samples at time t = 0, T, 2T, . produces output samples at time t = 0, T/n, 2T/n, . (where n is an integer), any output sample being a linear combination of the past and present inputs and outputs. The multirate controller achieves a lower intersampling ripple and a faster settling time in comparison with its single-rate predecessor at no increase, in most cases, in the number of the required storage elements.
Evolutionary repurposing of a sulfatase: A new Michaelis complex leads to efficient transition state charge offset

Significance The versatility of promiscuous enzymes plays a key role in the evolution of catalysts. This work addresses the molecular mechanism of repurposing a promiscuous enzyme by laboratory evolution and reveals that mutations distinct from the catalytic machinery reshaped the active site. Evolution fine-tuned binding of a previously disfavored Michaelis complex (E·S), repositioning the promiscuous substrate to enable better charge offset during leaving group departure in the transition state. The functional transition relies on maintaining the reactivity of existing catalytic groups in a permissive active-site architecture, able to accommodate multiple substrate binding modes, without requiring changes in conformational dynamics. Such a parsimonious route to higher efficiency illustrates a molecular scenario in which catalytic promiscuity facilitates short adaptive pathways of evolution. The recruitment and evolutionary optimization of promiscuous enzymes is key to the rapid adaptation of organisms to changing environments. Our understanding of the precise mechanisms underlying enzyme repurposing is, however, limited: What are the active-site features that enable the molecular recognition of multiple substrates with contrasting catalytic requirements? To gain insights into the molecular determinants of adaptation in promiscuous enzymes, we performed the laboratory evolution of an arylsulfatase to improve its initially weak phenylphosphonate hydrolase activity. The evolutionary trajectory led to a 100,000-fold enhancement of phenylphosphonate hydrolysis, while the native sulfate and promiscuous phosphate mono- and diester hydrolyses were only marginally affected (≤50-fold). Structural, kinetic, and in silico characterizations of the evolutionary intermediates revealed that two key mutations, T50A and M72V, locally reshaped the active site, improving access to the catalytic machinery for the phosphonate. Measured transition state (TS) charge changes along the trajectory suggest the creation of a new Michaelis complex (E•S, enzyme–substrate), with enhanced leaving group stabilization in the TS for the promiscuous phosphonate (β leaving group from −1.08 to −0.42). Rather than altering the catalytic machinery, evolutionary repurposing was achieved by fine-tuning the molecular recognition of the phosphonate in the Michaelis complex, and by extension, also in the TS. This molecular scenario constitutes a mechanistic alternative to adaptation solely based on enzyme flexibility and conformational selection. Instead, rapid functional transitions between distinct chemical reactions rely on the high reactivity of permissive active-site architectures that allow multiple substrate binding modes.
Precision Stabilization Systems

This paper discusses the relationships that must be considered in analyzing the design and performance of typical precision stabilization systems. In particular, the disturbance inputs that are due to kinematic and geometrical coupling are examined in depth by considering systems implemented with either a conventional two-axis gimbal or a traditional half-angle mirror assembly. The disturbance coupling that is associated with the gimbal drive actuators and the effect of structural compliance on the stabilization control loops are also discussed in detail. Other aspects of stabilization system design that are considered include the potential improvements in performance that can be achieved by using appropriate multiaxis gimbal configurations and by utilizing the angular pointing characterisitics of beam expansion telescopes.
A method for estimating optimal crystal cuts and propagation directions for excitation of piezoelectric surface waves

A criterion for judging the relative effeciency of excitation of piezoelectric surface waves as a function of crystal plate orientation and propagation direction is developed. This criterion is based on a velocity change upon application of a thin conducting sheet to the surface. Plots of surface wave velocity for various orientations of the crystal surface are presented as a function of propagation direction for the conducting sheet in contact with and infinitely far removed from the crystal surface. A plot of a typical velocity variation as a function of height of the conducting sheet is also presented. Evidence in support of the criterion of using velocity changes as an indicator of efficiency is presented in the form of mechanical displacement and electric potential plots for several orientations and propagation directions. All velocity displacements and potential calculations were carried out under the assumption that the crystal medium was lithium niobate.
Convolution and Correlation Using Nonlinear Interactions of Lamb Waves

Excitation of Lamb waves in several of the lower order modes has been demonstrated on polarized plates of PZT using interdigital transducers. It is shown that these waves cannot only be used in dispersive delay lines, but also that convolution and correlation can be efficiently performed using the nonlinear interaction between acoustic plate waves propagating in the same or different modes. The fact that plate modes exist with a broad range of velocities while they maintain the accessibility and high energy density of surface waves enables these devices to combine the advantages of pre- vious bulk and surface wave methods.
Shear stress promotes differentiation of stem cells from human exfoliated deciduous teeth into endothelial cells via the downstream pathway of VEGF-Notch signaling

Effects of shear stress on endotheliaxl differentiation of stem cells from human exfoliated deciduous teeth (SHEDs) were investigated. SHEDs were treated with shear stress, then reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was performed to analyse the mRNA expression of arterial markers and western blot analysis was performed to analyse protein expression of angiogenic markers. Additionally, in vitro matrigel angiogenesis assay was performed to evaluate vascular-like structure formation. The secreted protein expression levels of the vascular endothelial growth factor (VEGF) of SHEDs after shear stress was also quantified using corresponding ELISA kits. Untreated SHEDs seeded on Matrigel cannot form vessel-like structures at any time points, whereas groups treated with shear stress formed a few vessel-like structures at 4, 8 and 12 h. When SHEDs were treated with EphrinB2-siRNA for 24, the capability of vessel-like structure formation was suppressed. After being treated with shear stress, the expression of VEGF, VEGFR2, DLL4, Notch1, EphrinB2, Hey1 and Hey2 (arterial markers) gene expression was significantly upregulated, moreover, the protein levels of VEGFR2, EphrinB2, CD31, Notch1, DLL4, Hey1, and Hey2 were also significantly upregulated. Both the mRNA and protein expression levels of EphB4 (venous marker) were downregulated. The average VEGF protein concentration in supernatants secreted by shear stress treated SHEDs groups increased significantly. In conclusion, shear stress was able to induce arterial endothelial differentiation of stem cells from human exfoliated deciduous teeth, and VEGF-DLL4/Notch-EphrinB2 signaling was involved in this process.
Task Difficulty Makes ‘No’ Response Different From ‘Yes’ Response in Detection of Fragmented Object Contours

Two-alternative forced choice tasks are often used in object detection, which regards detecting an object as a ‘yes’ response and detecting no object as a ‘no’ response. Previous studies have suggested that the processing of yes/no responses arises from identical or similar processing. In this study, we investigated the difference of processing between detecting an object (‘yes’ response) and not detecting any object (‘no’ response) by controlling the task difficulty in terms of fragment length and stimulus duration. The results indicated that a ‘yes’ response depends on accurate and stable decisions through grouping processing, and a ‘no’ response might involve two distinct processing, including accurate decisions and intuitive decisions. Accurate decisions of ‘no’ may arise after the rejection of a ‘yes’ response with grouping processing, which is an accurate but slow response in an easy task. Intuitive decisions of ‘no’ arise as the result of breaking down the decision process when the received information was insufficient for grouping processing in a difficult task. Therefore, intuitive decisions of ‘no’ arise quickly but are inaccurate. The different processes associated with yes/no responses were discussed in terms of the hierarchal structure of object recognition, especially with respect to receiving information and grouping.
A nonlinear integrator for servomechanisms

INTEGRATION in the forward part of a servomechanism loop has long been known to reduce steady-state errors. With one perfect integrator, there will be no steady-state error following a simple step-function input; with two tandem integrators there will be no steady-state error due to a ramp input, etc. The major drawback to the linear integrator is the time delay involved. Each linear integrator introduces 90 degrees of phase lag at all frequencies, and so it takes only two integrators to make a basically unstable system. A nonlinear integrator is to be described which is superior in this respect to a linear type.
Equivalent Circuits and Performance Calculations of Canned Motors

In this paper, new equivalent circuits and procedures are given for calculating the speed-, torque-, current-curves, and stray losses of induction motors having solid steel rotors as well as slot-embedded squirrel-cage bars. The new procedures include effects of eddy currents in the solid steel rotor in parallel with the squirrel-cage bar currents, using two alternative forms of the equivalent circuit. It was found that the presence of the solid iron reduced the zigzag leakage reactance of the rotor bars, allowing more tooth frequency currents to flow in these bars; thereby markedly increasing the stray load loss when the air gap is small. By increasing the air gap, this type of loss is markedly reduced. The losses due to phase-belt harmonics can be reduced by interspersing. The test results are in excellent agreement with the calculated values.
A learning method for system identification

A method for system identification is proposed which is based on the error-correcting training procedure in learning machines, and is referred to as "learning identification. " This learning identification is nondisturbing, is applicable to cases where the input signal is random and nonstationary, and can be completed within a short time, so that it may be used to identify linear quasi-time-invariant systems in which some parameters vary slowly in comparison with the time required for identification. This merit also makes it possible to eliminate noise disturbances by means of the moving average method. Computer simulation of the learning identification was carried out and the times required for identification were obtained for various cases. Some modifications of the learning identification were also investigated together with their computer simulations.