Mediterranean winter rainfall in phase with African monsoons during the past 1.36 million years

Mediterranean climates are characterized by strong seasonal contrasts between dry summers and wet winters. Changes in winter rainfall are critical for regional socioeconomic development, but are difficult to simulate accurately1 and reconstruct on Quaternary timescales. This is partly because regional hydroclimate records that cover multiple glacial–interglacial cycles2,3 with different orbital geometries, global ice volume and atmospheric greenhouse gas concentrations are scarce. Moreover, the underlying mechanisms of change and their persistence remain unexplored. Here we show that, over the past 1.36 million years, wet winters in the northcentral Mediterranean tend to occur with high contrasts in local, seasonal insolation and a vigorous African summer monsoon. Our proxy time series from Lake Ohrid on the Balkan Peninsula, together with a 784,000-year transient climate model hindcast, suggest that increased sea surface temperatures amplify local cyclone development and refuel North Atlantic low-pressure systems that enter the Mediterranean during phases of low continental ice volume and high concentrations of atmospheric greenhouse gases. A comparison with modern reanalysis data shows that current drivers of the amount of rainfall in the Mediterranean share some similarities to those that drive the reconstructed increases in precipitation. Our data cover multiple insolation maxima and are therefore an important benchmark for testing climate model performance

Hafnium carbide as a barrier in multilayer coatings by chemical vapor deposition (CVD)

Hafnium Carbide (HfC) is used as a wear resistant coating for hard metal cutting tools as well as a barrier for oxygen in multilayer coatings to protect Carbon Fibre reinforced Carbon composite materials (CFC) at high temperatures. Chemical Vapor Deposition (CVD) allows the production of this refractory carbide above temperatures of 850°C, far away from its melting point of 3930°C. Hafnium (IV) chloride (HfCl4) and methane (CH4) in an excess of hydrogen (H2) are used as precursors. The reproducibility and the standard deviation of the process was tested at constant process conditions. The effect of the deposition conditions such as total pressure, molar fraction of hydrogen and the influence of additional hydrogen chloride in the reaction gas on the HfC - deposition rate (dpr) is investigated. The composition of the HfC layers was determined using Electron Probe Micro Analysis (EPMA). The oxidation stability of multilayer coated CFC composites is tested in a thermobalance, in a temperature range between 380° and 868°C

Investigations on TiN, TiC and Ti(CN) obtained by chemical vapor deposition

The paper presents the results of the chemical vapour deposition (CVD) of TiN, TiC and Ti(CN) using TiCl4, H2, N2 and CH4 as educts. The influence of the deposition conditions like temperature, total pressure and composition of the reaction gases on the deposition process is studied and a model for the deposition rate is proposed. The deposition process of TiN, TiC and Ti(CN) up to a TiCl4 partial pressure of 3.8 kPa can well be described by a power law of first order. Reducing the total pressure results in an increased deposition rate, higher apparent activation energy, lower depletion of the reaction gas and more uniform coatings. The composition of TiN and TiC films is not stoichiometric with respect to N and C (TiN0.6, TiC0.7) and independent of the deposition conditions. The composition of Ti(CN) can be changed by varying the reaction temperature, which allows to deposit graded layers. Ceramics coated with TiN and Ti(CN) achieve the lowest value of electrical resistivity (34 µohm.cm) at a layer thickness of 11 µm. For TiC a 25 µm layer is needed in order to achieve a minimum value of 209 µohm.cm

A SIGNAL ENHANCED PORTABLE RAMAN PROBE FOR ANESTHETIC GAS MONITORING

The spontaneous Raman scattering technique is an excellent tool for a quantitative analysis of multi-species gas mixtures. It is a noninvasive optical method for species identification and gas phase concentration measurement of all Raman active molecules, since the intensity of the species specific Raman signal is linearly dependent on the concentration. Applying a continuous wave (CW) laser it typically takes a few seconds to capture a gas phase Raman spectrum at room temperature. Nevertheless in contrast to these advantages the weak Raman signal intensity is a major drawback. Thus, it is still challenging to detect gas phase Raman spectra in alow-pressure regime with a temporal resolution of only a few 100 ms. In this work a fully functional gas phase Raman system for measurements in the low-pressure regime (p ≥ 980 hPa (absolute)) is presented. It overcomes the drawback of a weak Raman signal by using a multipass cavity. A description of the sensor setup and of the multipass arrangement will be presented. Moreover the complete functionality of the sensor system will be demonstrated by measurements at an anesthesia simulator under clinical relevant conditions and in comparison to a conventional gas monitor

Decision-making in cold chain logistics using data analytics: a literature review

Purpose: The purpose of the paper is to identify the multiple types of data that can be collected and analyzed by practitioners across the cold chain, the ICT infrastructure required to enable data capture and how to utilize the data for decision-making in cold chain logistics. Design/methodology/approach: Content analysis based literature review of 38 selected research articles, published between 2000 and 2016, was used to create an overview of data capture, technologies used for collection and sharing of data, and decision making that can be supported by the data, across the cold chain and for different types of perishable food products. Findings: There is a need to understand how continuous monitoring of conditions such as temperature, humidity, vibration can be translated to support real-time assessment of quality, determination of actual remaining shelf life of products and use of those for decision making in cold chains. Firms across the cold chain need to adopt appropriate technologies suited to the specific contexts to capture data across the cold chain. Analysis of such data over longer periods can also unearth patterns of product deterioration under different transportation conditions, which can lead to redesigning the transportation network to minimize quality loss or to take precautions to avoid the adverse transportation conditions. Research limitations and implications: The findings need to be validated through further empirical research and modeling. There are opportunities to identify all relevant parameters to capture product condition as well as transaction data across the cold chain processes for fish, meat and dairy products. Such data can then be used for supply chain planning and pricing products in the retail stores based on product conditions and traceability information. Addressing some of the above research gaps will call for multi-disciplinary research involving food science and engineering, information technologies, computer science and logistics and supply chain management scholars. Practical implications: The findings of this research can be beneficial for multiple players involved in the cold chain like food processing companies, logistics service providers, ports and wholesalers and retailers to understand how data can be effectively used for better decision-making in cold chain and to invest in the specific technologies which will suit the purpose. To ensure adoption of data analytics across the cold chain, it is also important to identify the player in the cold chain, which will drive and coordinate the effort. Originality/value This paper is one of the earliest to recognize the need for a comprehensive assessment for adoption and application of data analytics in cold chain management and provides directions for future research

Coating of continuous carbon fibers with double layers by chemical vapor deposition

A theoretical approach for the description of the chemical vapor infiltration (CVI) of continuous carbon fiber bundle is used to predict the homogeneity of the infiltration into a fiber bundle as a function of the temperature. Required input for the model is the rate constant of the chemical reaction and the effective diffusion coefficient, including the geometric parameter of the fiber bundle. The mechanical properties of SiC coated carbon fibers are measured in a single filament test and evaluated using the Weibull statistics. SiC nanolayer of about 45 nm thickness decreases the fiber tensile strength to 88 % of the value of an uncoated fiber. On the other hand, pyrolytical carbon (pyC) films improve their mechanical properties. Combining these two effects in applying a double layer coating consisting of pyC/SiC or pyC/TiN in a single step process, it is possible to slightly increase the tensile strength of the carbon fibers. SEM and TEM analysis also show a uniform distribution of the layer thickness within the fiber bundle and confirm the layer thickness measured experimentall

Development and steroidogenic capacity of adult Leydig cell population in experimental conditions of hyperglycemia and obesity

Introduction and Aim: The metabolic syndrome involves various abnormalities like obesity, insulin resistance/ diabetes, hypertension, and hormonal disorders. It is a serious risk factor for male infertility, often associated with compromised hypothalamic-pituitary-gonadal axis. The aim of the present study was to evaluate adult Ley­dig cell (LC) number and steroidogenesis in tandem with macro biomarkers (body and testis weight, fat accumu­lation) in experimental conditions of diabetes mellitus (DM) induced on day 1 (neonatally, NDM) or day 10 (pre­pubertally, PDM); short- and long-term high-fat diet (HFD) with induced obesity in rats since puberty.Results: Significant increase was established in body weight and body fat in short- and long-term HFD. It was as­sociated with a decrease in relative testicular weight in long-term HFD (gonado-somatic index). Epididymal and inguinal adipocyte diameters were increased in the animals from both groups.HFD did not affect significantly serum testosterone and LH levels. Nevertheless, expression of LC key steroido­genic factors and intratesticular testosterone levels were significantly lower in long-term HFD rats, associated with a reduction of the LC number.Hyperglycaemia was confirmed by a significant elevation of blood glucose levels by 15% in adult NDM and by 35% in PDM rats. In NDM body weight and testicular weight were increased but the gonado-somatic index was de­creased by 15%. PDM rats had normal body weight but the testicular weight and gonado-somatic index were de­creased by 30%. Leydig cell number and testosterone production were in normal range in adult NDM, whereas they were significantly decreased in PDM.Conclusion: Our results from the HFD experimental model demonstrated that long-term HFD influenced nega­tively the number of Leydig cells and testosterone production. Prepubertal DM, but not neonatal DM, suppressed Leydig cell development and steroidogenesis in adulthood. Altogether, our data indicated that diabetes and obe­sity affected the size of adult Leydig cell population and testicular steroidogenic function and they were associat­ed with reduced macroparameters - body weight, absolute and relative testicular weight

Rational development of nanomedicines for molecular targeting in periodontal disease

Recent advances in understanding the etiology and pathogenesis of periodontal disease and polymicrobial synergy in the dysbiotic oral microbial community endorsed novel therapeutic targets and assured further improvement in periodontal disease treatment. Moreover, understanding of the events at the molecular level inspired the researchers to alleviate the stress from the disease by applying the bottom-up approach and delivering the drugs at the site of action, using nanoscale medicines. This review is focused on promising strategies for rational design of nanopaharmaceuticals for periodontal disease treatment based on novel therapeutic targets and the potential of advanced concepts for inflammation cascade targeting. Due to their size, nanomedicines are capable to interact with the elements of the immune system through cell receptor binding and to subsequently influence specific intracellular signaling pathways activation. They might also interfere with different signaling molecules continuously involved in the disease progression, in order to abolish cell activation and block the production of proinflammatory substances. Different biomacromolecules can be trafficked to the site of action using nanomedicines for gene targeting: i) decoy oligodeoxynucleotide (ODN) for suppression of NF-?B transcription activity, ii) DNA therapeutics for modulation of cell inflammatory response and iii) siRNA for cytokine production silencing. However, despite the potential of the nanotechnology for improvement of periodontal disease treatment, the translation of nano-drug delivery systems to clinical therapy is hindered by the lack of standard procedures for proper safety and efficacy profile evaluation