Volcanic products of Lipari (Aeolian islands,Italy): Multivariate analysis of petrographic and radiometric data

A petrographic and radiometric study, along with statistical multivariate analysis of volcanic products of the island of Lipari (Aeolian islands, Italy) was carried out. The volcanological history of Lipari was reconstructed defining two stages (pre- and post-erosive stages) further on subdivided in four volcanic phases, each of which characterized by products with a particular chemical composition and separated by stratigraphic unconformities. The correlations between petrographic features, determined by X-ray fluorescence, and volcanological history of the island highlight a gradual differentiation with younger rocks showing a more acid chemical composition than the older ones. Radiometric features, and in particular the content of primordial radionuclides ²³⁸U, ²³²Th and ⁴⁰K, have been measured through gamma-ray spectrometry with hyper-pure germanium detector.The different volcanic lithologies, such as basalts, andesites and rhyolites, have been characterized by petrographic diagrams. The calculated dose rate has also been used as an additional classification parameter.Older products show low alkali content than the younger ones. This is related with the increasing of incompatible elements, such as uranium and thorium, in the younger products.Principal components and hierarchical clustering statistical analyses have provided additional information on sample differentiation and similarities.     

EPR data on volcanic siliceous glasses from the Eastern Rhodopes (Bulgaria) and the Lipari Island (Italy)

High-silica content natural volcanic glasses of different colour from the Studen Kladenetz, Ustra and Tatarevo paleovolcanoes (Eastern Rhodopes, Bulgaria) and from the Lipari Island (Aeolean Islands, Italy) are studied by EPR in order to obtain data on the type of paramagnetic defects and their influence on the processes of pumice formation and on the nature of colouration of the glasses. According to the EPR data, the content of both the structural Fe³⁺ and Fe microphases correlates to the colour of the pumices and the perlites (reverse tendency for the Fe³⁺ signal). In some samples an EPR spectrum of Mn²⁺ has been observed. The colour of pumices from the Lipari Island changes from black to white as the degree of vesiculation increases. *** DIRECT SUPPORT *** A03QQ020 00015     

Bronze Age pottery from the Aeolian Islands: definition of Temper Compositional Reference Units by an integrated mineralogical and microchemical approach

An integrated microchemical–petrographic approach is here proposed to discriminate the provenance of archaeological pottery artefacts from distinct production centres. Our study focuses on a statistically significant sampling (n=186) of volcanic temper-bearing potteries representative of the manufacturing and dispersion among the islands of the Aeolian Archipelago during the Bronze Age. The widespread establishment of new settlements and the abundant recovery of Aeolian-made ceramic in southern Italy attest for the increased vitality of the Archipelago during the Capo Graziano culture (Early Bronze Age–Middle Bronze Age 2; 2300–1430 BC). Potteries from three of the main known ancient communities (Lipari, Filicudi and Stromboli) have been studied integrating old collections and newly excavated material. Volcanic tempers have been first investigated through multivariate analyses of relative abundances of mineral and rock clasts along with petrographic characters. In addition, we performed in-situ mineral chemistry microanalyses by Electron Microprobe and Laser Ablation—Inductively Coupled Plasma Mass Spectrometry to assess major and trace element composition of the most common mineral phases. Four Temper Compositional Reference Units have been recognised based on compositional trends. Two units (AI and AX) are unequivocally distinct by their peculiar trace element enrichment and petrographic composition; they mostly contain samples from the sites of Lipari and Stromboli, respectively. Units AIV and AVIII, restricted to the sites of Filicudi and Stromboli, show distinct petrographic characters but overlapped geochemical fingerprints.     

Pigments characterization of polychrome vases production at Lipára: New insights by noninvasive spectroscopic methods

One of the most impressive Sicilian pottery production is attributed to the so‐called Lipari Painter and his followers, whose vessels—found in the archeological site of Lipari (Aeolian Island, Sicily)—are decorated with characteristic blue, red, and white figures. From the archeological point of view, these artworks keep open many questions concerning dating, production technique, and cultural background. In this context, new data on the manufacture procedures and on the raw materials used for the pigments may contribute to a deeper comprehension of this early Hellenistic vase tradition. The preciousness of the vessels, exhibited at the Archeological Museum of Lipari, imposed the use of in situ nondestructive methods to address new insights on the nature of the colored layers. Thus, analyses by Raman and X‐ray fluorescence spectroscopy have been performed with portable instruments on a selection of vessels certainly attributed to Lipari Painter and to some others of his followers. The results of this study testify the use of different pigments: kaolin and gypsum, probably supplied locally, for white layers; Egyptian blue for blue hues; red ochre for brown‐reddish hues; and cinnabar for pink and red‐purple nuances. The identification of both Egyptian blue and cinnabar opens an interesting discussion about dating and circulation of the raw materials.     

Equilibrium of a two-route system with delayed information feedback strategies

In intelligent transport system, some advanced information feedback strategies have been developed to reduce the oscillations and enhance the capacity on the road level. However, seldom strategies have considered the information delay and user equilibrium (UE) objective. Here, a derivative cost feedback strategy (DCFS) is proposed to reduce the influence of the delay, based on the UE principle. The simulation results show that in both no-delay and delay information cases, DCFS are the best and can make the system reaching the UE. Because DCFS can predict the trend of the travel cost.     

Ultrasonic extraction of oil from tobacco (Nicotiana tabacum L.) seeds

The ultrasonic extraction (UE) of oil from the seeds of a semi-oriental tobacco (Nicotiana tabacum L.) plant strain by using n-hexane and petroleum ether was studied at different temperatures and seeds-to-solvent ratios. The oil yield depended on the seed comminution, the extraction temperature, the seeds-to-solvent ratio and the type of solvent. The oil yield was much higher if the seeds were ground before extraction. The oil yield increased with increasing the extraction temperature and with decreasing the seeds-to-solvent ratio. n-Hexane was somewhat more efficient in the oil extraction than petroleum ether. In recovering the tobacco seed oil (TSO), the UE was less efficient than the Soxhlet extraction. The advantage of the UE was a relatively high oil yield at 25 degrees C in a shorter time. The kinetics of UE of TSO was described using the model of unsteady diffusion through plant material.     

Impact of ultrasound-assisted extraction on quality and photostability of the Pothomorphe umbellata extracts

Pothomorphe umbellata (L.) Miq. is a Brazilian shrub with therapeutic and economic applications. There are some reports on the technological development of P. umbellata preparations; however, there are no studies on the influence of non-conventional extraction procedures on the quality of P. umbellata extracts. The aim of this study was to evaluate the effects of the ultrasound-assisted extraction (UE) parameters upon the extraction yield (EY%) of 4-nerolidylcatechol (4-NC) and the antioxidant activity of P. umbellata extracts using a factorial design and response surface methodology. Extracts obtained by UE and percolation were compared, and the photostability of 4-NC was evaluated via the exposure of UVA and visible light to the samples. The most influential variables observed for the UE were the ethanol-to-water and drug-to-solvent ratios. UE improved the extraction kinetics of 4-NC from plant material and improved the antioxidant activity of the extracts. Some of the ultrasound extracts showed an antioxidant activity that was not proportional to their 4-NC concentration, which suggests the presence of other active antioxidant compounds in these P. umbellata extracts. There was no significant difference in the photostability of 4-NC between the percolated and ultrasound extracts. Surprisingly, the isolated 4-NC material was significantly more stable when exposed to UVA-visible light compared to 4-NC in the plant extracts.     

A fuzzy logic approach to modeling the underground economy in Taiwan

The size of the ‘underground economy’ (UE) is valuable information in the formulation of macroeconomic and fiscal policy. This study applies fuzzy set theory and fuzzy logic to model Taiwan's UE over the period from 1960 to 2003. Two major factors affecting the size of the UE, the effective tax rate and the degree of government regulation, are used. The size of Taiwan's UE is scaled and compared with those of other models. Although our approach yields different estimates, similar patterns and leading are exhibited throughout the period. The advantage of applying fuzzy logic is twofold. First, it can avoid the complex calculations in conventional econometric models. Second, fuzzy rules with linguistic terms are easy for human to understand.     

RAT selection for IoT devices in HetNets: Reinforcement learning with hybrid SMDP algorithm

Due to the increasing deployment of heterogeneous networks (HetNets), the selection of which radio access technologies (RATs) for Internet of Things (IoT) devices such as user equipments (UEs) has recently received extensive attention in mobility management research. Most of existing RAT selection methods only optimize the selection strategies from the UE side or network side, which results in heavy network congestion, poor user experience and system utility degradation. In this paper the UE side and the network side are considered comprehensively, based on the game theory (GT) model we propose a reinforcement learning with assisted network information algorithm to overcome the crucial points. The assisted information is formulated as a semi-Markov decision process (SMDP) provided for UEs to make accurate decisions, and we adopt the iteration approach to reach the optimal policy. Moreover, we investigate the impacts of different parameters on the system utility and handover performance. Numerical results validate that our proposed algorithm can mitigate unnecessary handovers and improve system throughputs.     

A dual phase genetic algorithm for improved initial access in 5G millimeter wave communication

Initial access (IA) in 5G millimeter wave (mmWave) communication is the problem of establishing a directional link between the base station (BS) and the user equipment (UE). For a multiple-input multiple-output (MIMO) system, where both the BS and UE have many antennas, finding the optimal beams can be prohibitively expensive in terms of delay and computation. In this work, we propose a meta-heuristic approach which is a modified dual-phase genetic algorithm. Since it is a meta-heuristic approach, it is generic and hence does not require extensive modifications to apply to different scenarios, it also does not require context information such as prior knowledge of channel state or statistics of user behavior. The proposed method is using iterative search for the optimal beams, but switch to a different fine-grained search phase on later iterations in order to quickly converge to the local optimum. The effect of this approach is analyzed in terms of capacity achieved vs number of transmit and receive antennas at BS and UE, codebook size, outage probability, total transmitted power, and other parameters specific to this particular dual-phase method. The proposed work has shown improved performance when compared to the existing similar work done in Souto et al. (2019) in terms of capacity achieved (2.12%), reduced power consumption (8.57%), and reduced IA delay (35% to 50%).     

Ultrasound biomicroscopy measurement of skin thickness change induced by cosmetic treatment with ultrasound stimulation

Moisturizing creams and lotions are commonly used in daily life for beauty and treatment of different skin conditions such as dryness and wrinkling, and ultrasound stimulation has been used to enhance the delivery of ingredients into skin. However, there is a lack of convenient methods to study the effect of ultrasound stimulation on lotion absorption by skin in vivo. Ultrasound biomicroscopy was adopted as a viable tool in this study to investigate the effectiveness of ultrasound stimulation on the enhancement of lotion delivery into skin. The forearm skin of 10 male and 10 female young subjects was tested at three different sites, including two lotion treatment sites with (Ultrasound Equipment – UE ON) and without (UE OFF) ultrasound stimulation and a control site without any lotion treatment. 1 MHz ultrasound with a duty cycle of 1.7%, a spatial peak temporal peak pressure of 195 kPa and an average power of 0.43 W was used for the stimulation. The skin thickness before, immediately after (0 min), and 15 and 30 min after the treatment was measured by an ultrasound biomicroscopic system (55 MHz). It was found that the skin thickness significantly increased immediately after the lotion treatment for both UE ON (from 1.379 ± 0.187 mm to 1.466 ± 0.182 mm, p < 0.001) and UE OFF (from 1.396 ± 0.193 mm to 1.430 ± 0.194 mm, p < 0.001) groups. Further comparison between the two groups revealed that the skin thickness increase of UE ON group was significantly larger than that of UE OFF group (6.5 ± 2.4% vs. 2.5 ± 1.3%, p < 0.001). Furthermore, it was disclosed that the enhancement of lotion delivery by ultrasound stimulation was more effective for the female subjects than the male subjects (7.6 ± 2.3% vs. 5.4 ± 2.0% immediately after treatment, p = 0.017). In conclusion, this study demonstrated that ultrasound biomicroscopy was a feasible method for studying the effectiveness of lotion treatment in vivo, and ultrasound stimulation was effective to enhance the rate of lotion absorption into skin.     

Dynamical evolution processes of traffic flow and travel cost in urban transportation networks

Considering such a fact that travellers dynamically adjust their routes and the resultant link traffic flows in a network evolve over time, this paper proposes a dynamical evolutionary model of the traffic assignment problem with endogenous origin-destination （OD） demands. The model＇s stability is analysed and the resultant user equilibrium （UE） state is shown to be stable under certain conditions. Numerical results in a grid network indicate that the model can generate convergent flow patterns and finally terminates at the UE state. Impacts by the parameters associated with OD demand function and link cost function are also investigated.     

溶解有机物三维荧光光谱技术在赤潮藻识别中的应用

将赤潮藻生长过程中产生的荧光溶解有机物(fluorescent dissolved organic matter,FDOM)的三维荧光光谱与主成分分析相结合,尝试建立了我国沿海10种常见赤潮藻的识别测定技术.用主成分分析提取三维荧光光谱第一主成分载荷谱作为识别特征谱,建立了浮游植物荧光特征谱库,在此基础上利用Bayes...     

Shallow acceptor wavefunctions with correct asymptotic behaviour

The wavefunction of the shallow acceptor in Ge is studied in the spherical approximation of Baldereschi and Lipari. The solution of the acceptor problem in the asymptotic limit is used for construction of trial functions. The functions composed of a few exponentials yield the ground state energy of ?9.9 meV and possess the asymptotic behaviour accounting well for the hopping conductivity dependence on the acceptor concentration.     

Excitation spectrum of the lithium acceptor in CdTe and estimation of the valence band parameters

The infrared absorption of lithium doped CdTe shows sharp lines in the energy range 30–80 meV which are attributed to electronic transitions from the ground state to the excited states in the lithium acceptor and LO phonon assisted transitions. This excitation spectrum is analyzed using the theory of Baldereschi and Lipari what leads to a determination of the Luttinger valence band parameters.     

Recent trends in the applications of sonochemical reactors as an advanced oxidation process for the remediation of microbial hazards associated with water and wastewater: A critical review

Water is one of the major sources that spread human diseases through contamination with bacteria and other pathogenic microorganisms. This review focuses on microbial hazards as they are often present in water and wastewater and cause various human diseases. Among the currently used disinfection methods, sonochemical reactors (SCRs) that produce free radicals combined with advanced oxidation processes (AOPs) have received significant attention from the scientific community. Also, this review discussed various types of cavitation reactors, such as acoustic cavitation reactors (ACRs) utilizing ultrasonic energy (UE), which had been widely employed, involving AOPs for treating contaminated waters. Besides ACRs, hydrodynamic cavitation reactors (HCRs) also effectively destroy and deactivate microorganisms to varying degrees. Cavitation is the fundamental phenomenon responsible for initiating many sonochemical reactions in liquids. Bacterial degradation occurs mainly due to the thinning of microbial membranes, local warming, and the generation of free radicals due to cavitation. Over the years, although extensive investigations have focused on the antimicrobial effects of UE (ultrasonic energy), the primary mechanism underlying the cavitation effects in the disinfection process, inactivation of microbes, and chemical reactions involved are still poorly understood. Therefore, studies under different conditions often lead to inconsistent results. This review investigates and compares other mechanisms and performances from greener and environmentally friendly sonochemical techniques to the remediation of microbial hazards associated with water and wastewater. Finally, the energy aspects, challenges, and recommendations for future perspectives have been provided.     

The Study on Infrared Scattering of Red Tide

Based on analyzing the infrared laser’s transmitting characteristic in the seawater, the concept about the red tide infrared scattering coefficient is introduced. By analyzing the relationship between the red tide infrared scattering coefficient and the red tide’s density, we bring forward a new method of monitoring the red tide based on detecting the red tide infrared scattering coefficient. According to Mie scattering theory, the scattering efficiency factor and the scattering phase function of the red tide particles in the ocean are simulated and calculated. The result proves that, as the radiuses of the red tide particles increase, the scattering efficiency factor oscillates, and the swing decreases gradually, and then approaches to 2. From the results of the scattering phase function, it can find that the scattering of the red tide particles is mainly a forward scattering for the infrared laser. Therefore, by analyzing the scattering efficiency factor and the scattering phase function of the red tide particles in the ocean, it can prove the feasibility of this red tide monitoring method in theory.     

RIS-assisted cell-free massive MIMO systems with reflection area: AP number reduction

Cell-free massive multiple-input multiple-output (MIMO) has been regarded as a promising technology due to high spectral efficiency. However, as large number of access points (APs) are deployed with fibers connecting to the central processing unit, the increase of energy consumption and hardware cost raise concerns. The reconfigurable intelligent surface (RIS) with impressing potential for low energy and cost finds a way to solve this problem. In this paper, we investigate the performance of the cell-free massive MIMO system with a RIS. As RIS can only reflect signals from the front, user equipments (UEs) and APs are divided into two categories according to their relative position with the RIS, i.e., one is on the reflection area of the RIS and the other is not. A closed-form approximation of the UE achievable downlink rate is derived. Based on it, we obtain the optimal RIS position and phase shift that can maximize the UE sum rate, through alternating optimization method. It is found that compared with the cell-free massive MIMO system without RIS, to achieve the same rate performance, the number of required AP in the RIS-assisted system can be significantly reduced. Moreover, as the RIS component increases, the number of required AP can be reduced almost linearly without rate reduction, which means the hardware and energy cost can be greatly cut down. Furthermore, from our simulation results, we can see that when users are densely distributed, the optimal location of the RIS should be closer to users. When users are uniformly distributed, the optimal position of RIS is close to the central position.     

基于SVM方法的赤潮生物优势种航空高光谱识别

赤潮生物优势种的航空高光谱识别可为快速鉴别赤潮及其毒性提供技术基础,为赤潮灾害程度的定级提供支持。文章提出了基于支持向量机(SVM)的赤潮生物优势种航空高光谱识别模型,并以2001年7月16日,2001年8月19日和8月25日的赤潮高光谱数据为例,开展了识别模型的实验应用。识别结果表明：在参考光谱具有较大动态范围的前提下,发展的赤潮生物优势种航空高光谱识别模型不仅能够获得较高的分类精度,而且不受高光谱数据维数高的限制。     

Higher excited states of acceptors in cubic semiconductors

For the first time, higher excited states of shallow acceptors up to the 3s and 4s states are calculated based on the Balderschi and Lipari theory including the cubic correction. The eigenvalues and eigenvectors of the effective mass Hamiltonian for shallow acceptor states were obtained by the finite element method. The resultant sparse matrix is diagonalized by a newly developed Saad's method based on Arnoldi's algorithm. Comparison with experimental spectra on ZnTe:Li and ZnTe:P gives best valence band parameters for ZnTe; μ = 0.60 and δ = 0.12.