Abstract: Boc(Boc= tert-butoxycarbonyl)-p-nitro-L-phenylalanyl-p-nitro-L-phenylalanine, a dipeptide characterized by acentric symmetry, self-assembles into micro-tapes. This study explores its thermal, structural, and nonlinear optical properties. Thermo-gravimetric analysis reveals an onset degradation temperature of 190 ºC, with primary and secondary peaks at 202 ºC and 220 ºC, respectively. The crystal structure of the dipeptide was determined through single crystal X-ray diffraction at 100 K, confirming its crystallization in space group P2 with two molecules per unit cell. Additionally, optical second harmonic generation polarimetry indicates a significant nonlinear optical response, with an effective coefficient (deff) estimated to be at least 0.52 pm/V. This value is only four times lower than that of state-of-the-art phase-matched β-barium borate nonlinear crystals, highlighting the potential of this dipeptide in nonlinear optical applications.

Abstract:

In this paper we consider time as a property of a preparation or a quantum system and investigate whether it is an epistemic property according to Harrigan and Spekkens’ criterion [Found Phys 40, 125–157 (2010)]. To be precise, using a tabletop setup where the predictions of quantum mechanics and general relativity can be combined, we prepare a quantum state such that it is a quantum superposition of the different durations ticked by a quantum mechanical clock moving in spacetime. Such a preparation provides a quantum system that includes time as an intrinsic property. Indeed, changing the weights in the superposition changes the time as an expectation value as well as the possible different clock readings and histories. With a proof similar to the Pusey-Barrett-Rudolph (PBR) theorem [Nature Phys 8, 475–478 (2012)], it is shown that time in quantum theory is not an epistemic notion, but has ontological reality. In fact, the PBR theorem implies an ontic notion of time. Indeed, by proving that the quantum state is a physical property, the PBR theorem requires quantum state reduction to be a physical process. In this case, quantum probabilities are intrinsic probabilities without epistemic origin, and they generate a genuinely new sequence of events. This novelty introduced by quantum probabilities can be interpreted as time. However, although the PBR theorem implies this result, it does not prove it. First, an additional assumption is required to ensure the intrinsic character of quantum probabilities. Second, the PBR theorem is not constructed to prove that time is ontic, but to prove that ψ is ontic. All these issues are discussed in detail in the paper.

Abstract: In this paper we propose new entropy of the apparent horizon $S_h=(1/\beta)\arctan(\beta S_{BH})$, where $S_{BH}$ is the Bekenstein--Hawking entropy. As parameter $\beta\rightarrow 0$ one comes to the Bekenstein--Hawking entropy. This allows us to consider the generalised Friedmann--Lema\^{i}tre--Robertson--Walker (FLRW) equations for the barotropic matter fluid with $p=w\rho$ for arbitrary equation of state parameter $w$. We obtain the matter pressure $p$ and density energy $\rho$ corresponding to the apparent horizon. The modified Friedmann's equations are found. The addition term in the second modified Friedmann's equation plays the role of a dynamical cosmological constant. The dark energy density, pressure and the deceleration parameter are found. It was shown that at some parameters $w$ and $\beta$ we can have two phases, acceleration and deceleration or the eternal inflation. The model under consideration by using the holographic principle describes the universe inflation. Thus, we consider the holographic dark energy model with the generalised entropy of the apparent horizon. New cosmology based on the generalized entropy can be of interest for a description of inflation and late time of the universe evolution.

Abstract: The high speeds seen in rapidly rotating pulsars after supernova explosions present a longstanding puzzle in astrophysics. Numerous theories have been suggested over the years to explain this sudden "kick" imparted to the neutron star, yet each comes with its own set of challenges and limitations. Key explanations for pulsar kicks include hydrodynamic instabilities in supernovae, anisotropic neutrino emission, asymmetries in the magnetic field, binary system disruption, and physics beyond the Standard Model. Unraveling the origins of pulsar kicks not only enhances our understanding of supernova mechanisms but also opens up possibilities for exploring new physics. In this brief review, we will introduce pulsar kicks, examine the leading hypotheses, and explore future directions for this intriguing phenomenon.

Abstract:

The exact nature of gravity remains unknown and widely debated despite the established theory of gravity (ETG) being more than a hundred years old. This paper presents a new theory on the cause of gravity and its effects. It demonstrates the shortcomings in the existing theory, including the lack of a full explanation of how matter warps space-time, the medium that fills empty space throughout the universe, as well as some inconsistency regarding the mechanism that causes one object to move towards another one. The new theory is then presented in two parts, starting with a description of the conditions necessary for one object to attract another one, followed by full details of the movement mechanism that is triggered when these conditions exist. The theory provides a complete explanation of gravity and its effect on matter.

Abstract: Hawking’s cosmology logically leads to an observed multiverse. This article argues it a superposition of at least three 3-dimensional universes in a 4-dimensional space, which each have two overlapping dimensions with the observed universe. For there is nothing outside it that could disturb the superposition, it could last forever. This explains why dark matter yields a linear decrease of gravity with distance to visible mass at large radii in galaxies. To prove this, all contributions of visible matter in the disks and bulbs, calculated by the SPARC team, have been recalculated to verify the brightness and gas density are correctly interpreted. Lelli and Mistele showed the common way to project dark matter halos around galaxies cannot be valid. Since application of General Relativity would need these halos too, it must be modified with additional terms. Bekenstein’s TeVeS does this. Using TeVeS, a decay of the contribution of dark matter to gravity with the expansion of space is confirmed. This explains the rapid development of large galaxies in the early universe that is reported by Labbé. A new prediction method for rotation velocities that works at all radii in galaxies is offered. It is 25% more accurate than MOND and TeVeS.

Abstract: With the wide application of UAVs in modern intelligent warfare and civil fields, the demand for C-UAS technology is increasingly urgent. Traditional detection methods have many limitations in dealing with "low, slow, and small" targets. This paper presents a pure laser automatic tracking system based on Geiger mode avalanche photodiode (Gm-APD). Combining the target motion state prediction of the Kalman filter and the adaptive target tracking of Camshift, a Cam-Kalm algorithm is proposed to achieve high-precision and stable tracking of moving targets. The system also introduces two-dimensional Gaussian fitting and edge detection algorithms to automatically determine the target's center position and the tracking rectangular box, improving the automation of target tracking. The experimental results show that the system designed in this paper can effectively track UAVs in a 70 m laboratory environment and 3.07 km to 3.32 km long-distance scene and has low center positioning error and MSE. This technology provides a new solution for real-time tracking and ranging of long-distance UAVs, shows the potential of pure laser in long-distance "low-slow-small" target tracking, and provides essential technical support for C-UAS technology.

Abstract: Dynamic power reduction in SRAM (Static Random Access Memory) is essential for improving energy efficiency in modern digital systems, especially in processors and embedded devices. As SRAM power consumption contributes significantly to overall chip power, optimizing power in SRAM is critical. This thesis explores recent techniques for dynamic power reduction in SRAM, with a focus on architectural modifications, dynamic voltage scaling, adaptive voltage supply, and optimized circuit designs. This abstract outlines the need for low-power SRAM in reducing heat, noise, and electro-migration, particularly in high-performance computing. The research highlights how Multi-Tree Voltage Regulator (MTR) techniques and other dynamic power management methods contribute to significant reductions in power and heat generation, thereby enhancing both performance and reliability.

Abstract: We present the growth of nickel oxide (NiO) thin films as a hole transport material in photovoltaic devices using e-beam evaporation technique. Such metal oxide layers were reactively deposited at 200 C substrate temperature using an electron beam evaporator under an oxygen atmosphere. The reactively grown oxide films through electron-beam evaporation have been optimized for carrier transport layers. Optical and structural characterizations were performed using UV–Vis spectrometry, X-ray diffraction technique, contact angle measurements, scanning electron microscopy, hall-effect measurements. The study of these films confirms that NiO layer is a suitable candidate to be used as a hole transport layer based on hall effect measurements. Morphological study using field emission scanning electron microscopy confirmed compact, uniform, and defect-free metal oxide layers growth. Contact angle measurements revealed that the films possessed semi-hydrophilic properties, contributing to improved stability by repelling water from their surfaces. The stoichiometry of the films was influenced by the oxygen pressure during deposition, which affected both their morphological and optical features. NiO films exhibited a transmittance exceeding 80% in the visible spectrum. These findings highlight the potential applications of such nickel oxide films as hole transport material layers.

Abstract:

This study investigated the accuracy and precision of a commercially available PNT solution that uses DGNSS-SBAS technology. Time and position data were sampled at a frequency of 20Hz during both short and long trajectory of a simulated controlled dry-land slalom, as well as during a real-world on-water slalom exercise. The primary objective was to assess the positional accuracy, availability, integrity, and service continuity of the PNT solution while evaluating its ability to differentiate between trajectories. Additionally, the simulated results were compared with an on-water real-world slalom test to validate the findings. The results of the controlled dry-land slalom test indicate that the PNT solution provided accurate measurements with an overall mean±SD Hrms of 0.20±0.02m. The integrity measures, HDOD and PDOP were found to be ideal to excellent, with values of 0.68±0.03, and 1.36±0.07, respectively. The PNT solution utilised an average of 20±1 satellites from the constellation, resulting in an accuracy of <1.5% when measuring the known trajectory of 50 simulated slalom runs. The data from the real-world on-water slalom test supported these findings, providing similar or improved results. Based on these findings, a PNT solution using DGNSS-SBAS can be considered effective means of tracking athlete trajectory in the sport of canoe slalom. Future research should be conducted to quantify its efficacy more precisely.