Effect of hydrochloric acid treated neetle fibre on oil absorbency

Hydrochloric acid (HCl) treatment on nettle fibres has been performed to improve the oil absorbency. Box-Behnken experimental design is used to study the influence of parameters, such as treatment time, treatment temperature and concentration on oil absorbency. It is observed that the maximum oil absorbency of 15.39 g/g of nettle fibres is achieved at 2 % of HCl concentration, 75°C of treatment temperature and 60 min of treatment time. Scanning electron microscopic study reveals that the raw nettle fibre surface exhibits waxy and protruding parts, and on HCl treatment the surface becomes rougher. The influence of other parameters such as stirring speed, environmental temperature and reusability on oil absorbency is also studied. Oil sorbed nettle fibres are also subjected to soil burial tests and burning tests. In conclusion, the raw nettle fibres only show an oil absorbency of 9.25 (g/g), whereas HCl treated nettle fibres show a maximum oil absorbency of 15.39 g/g.

Observing CMB polarisation through ice

Ice crystal clouds in the upper troposphere can generate polarisation signals at the uK level. This signal can seriously affect very sensitive ground based searches for E- and B-mode of Cosmic Microwave Background polarisation. In this paper we estimate this effect within the ClOVER experiment observing bands (97, 150 and 220 GHz) for the selected observing site (Llano de Chajnantor, Atacama desert, Chile). The results show that the polarisation signal from the clouds can be of the order of or even bigger than the CMB expected polarisation. Climatological data suggest that this signal is fairly constant over the whole year in Antarctica. On the other hand the stronger seasonal variability in Atacama allows for a 50% of clean observations during the dry season.Comment: 7 Pages, 4 figure

Effect of hydrochloric acid treated neetle fibre on oil absorbency

332-337Hydrochloric acid (HCl) treatment on nettle fibres has been performed to improve the oil absorbency. Box-Behnken experimental design is used to study the influence of parameters, such as treatment time, treatment temperature and concentration on oil absorbency. It is observed that the maximum oil absorbency of 15.39 g/g of nettle fibres is achieved at 2 % of HCl concentration, 75°C of treatment temperature and 60 min of treatment time. Scanning electron microscopic study reveals that the raw nettle fibre surface exhibits waxy and protruding parts, and on HCl treatment the surface becomes rougher. The influence of other parameters such as stirring speed, environmental temperature and reusability on oil absorbency is also studied. Oil sorbed nettle fibres are also subjected to soil burial tests and burning tests. In conclusion, the raw nettle fibres only show an oil absorbency of 9.25 (g/g), whereas HCl treated nettle fibres show a maximum oil absorbency of 15.39 g/g

Synthesis and characterisation of nickel-iron bimetallic oxide nanoparticles via microwave irradiation technique

953-958Nickel- Iron bimetallic oxide nanoparticles have been synthesized in ethylene glycol using microwave irradiation technique. The microwave assisted synthesized Nickel and iron oxide nanoparticles are combined together in 1:1 molar ratio and treated under microwave irradiation followed by calcination to get Ni-Fe bimetallic oxide. The structure and composition of nanoparticles are characterized by UV-visible spectroscopy, FT-IR, X-ray diffraction (XRD), energy dispersion spectroscopy (EDS) and transmission electron microscopy (TEM) techniques. The empirical formula of the nanoparticle is found as Ni1Fe1.6O2.9 at 500 ºC, Ni1Fe1.5O2.6 at 700 ºC and Ni1Fe2O2.7 at 900 ºC by varied reaction conditions. A maximum absorbance of 357.67 nm is observed in UV-visible spectrum. The average size of particles in all cases is found to be ~30 nm as confirmed from TEM images. Antibacterial and antifungal studies have not shown any appreciable results

The state of the Martian climate

60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

State of the climate in 2018

In 2018, the dominant greenhouse gases released into Earth’s atmosphere—carbon dioxide, methane, and nitrous oxide—continued their increase. The annual global average carbon dioxide concentration at Earth’s surface was 407.4 ± 0.1 ppm, the highest in the modern instrumental record and in ice core records dating back 800 000 years. Combined, greenhouse gases and several halogenated gases contribute just over 3 W m−2 to radiative forcing and represent a nearly 43% increase since 1990. Carbon dioxide is responsible for about 65% of this radiative forcing. With a weak La Niña in early 2018 transitioning to a weak El Niño by the year’s end, the global surface (land and ocean) temperature was the fourth highest on record, with only 2015 through 2017 being warmer. Several European countries reported record high annual temperatures. There were also more high, and fewer low, temperature extremes than in nearly all of the 68-year extremes record. Madagascar recorded a record daily temperature of 40.5°C in Morondava in March, while South Korea set its record high of 41.0°C in August in Hongcheon. Nawabshah, Pakistan, recorded its highest temperature of 50.2°C, which may be a new daily world record for April. Globally, the annual lower troposphere temperature was third to seventh highest, depending on the dataset analyzed. The lower stratospheric temperature was approximately fifth lowest. The 2018 Arctic land surface temperature was 1.2°C above the 1981–2010 average, tying for third highest in the 118-year record, following 2016 and 2017. June’s Arctic snow cover extent was almost half of what it was 35 years ago. Across Greenland, however, regional summer temperatures were generally below or near average. Additionally, a satellite survey of 47 glaciers in Greenland indicated a net increase in area for the first time since records began in 1999. Increasing permafrost temperatures were reported at most observation sites in the Arctic, with the overall increase of 0.1°–0.2°C between 2017 and 2018 being comparable to the highest rate of warming ever observed in the region. On 17 March, Arctic sea ice extent marked the second smallest annual maximum in the 38-year record, larger than only 2017. The minimum extent in 2018 was reached on 19 September and again on 23 September, tying 2008 and 2010 for the sixth lowest extent on record. The 23 September date tied 1997 as the latest sea ice minimum date on record. First-year ice now dominates the ice cover, comprising 77% of the March 2018 ice pack compared to 55% during the 1980s. Because thinner, younger ice is more vulnerable to melting out in summer, this shift in sea ice age has contributed to the decreasing trend in minimum ice extent. Regionally, Bering Sea ice extent was at record lows for almost the entire 2017/18 ice season. For the Antarctic continent as a whole, 2018 was warmer than average. On the highest points of the Antarctic Plateau, the automatic weather station Relay (74°S) broke or tied six monthly temperature records throughout the year, with August breaking its record by nearly 8°C. However, cool conditions in the western Bellingshausen Sea and Amundsen Sea sector contributed to a low melt season overall for 2017/18. High SSTs contributed to low summer sea ice extent in the Ross and Weddell Seas in 2018, underpinning the second lowest Antarctic summer minimum sea ice extent on record. Despite conducive conditions for its formation, the ozone hole at its maximum extent in September was near the 2000–18 mean, likely due to an ongoing slow decline in stratospheric chlorine monoxide concentration. Across the oceans, globally averaged SST decreased slightly since the record El Niño year of 2016 but was still far above the climatological mean. On average, SST is increasing at a rate of 0.10° ± 0.01°C decade−1 since 1950. The warming appeared largest in the tropical Indian Ocean and smallest in the North Pacific. The deeper ocean continues to warm year after year. For the seventh consecutive year, global annual mean sea level became the highest in the 26-year record, rising to 81 mm above the 1993 average. As anticipated in a warming climate, the hydrological cycle over the ocean is accelerating: dry regions are becoming drier and wet regions rainier. Closer to the equator, 95 named tropical storms were observed during 2018, well above the 1981–2010 average of 82. Eleven tropical cyclones reached Saffir–Simpson scale Category 5 intensity. North Atlantic Major Hurricane Michael’s landfall intensity of 140 kt was the fourth strongest for any continental U.S. hurricane landfall in the 168-year record. Michael caused more than 30 fatalities and $25 billion (U.S. dollars) in damages. In the western North Pacific, Super Typhoon Mangkhut led to 160 fatalities and$6 billion (U.S. dollars) in damages across the Philippines, Hong Kong, Macau, mainland China, Guam, and the Northern Mariana Islands. Tropical Storm Son-Tinh was responsible for 170 fatalities in Vietnam and Laos. Nearly all the islands of Micronesia experienced at least moderate impacts from various tropical cyclones. Across land, many areas around the globe received copious precipitation, notable at different time scales. Rodrigues and Réunion Island near southern Africa each reported their third wettest year on record. In Hawaii, 1262 mm precipitation at Waipā Gardens (Kauai) on 14–15 April set a new U.S. record for 24-h precipitation. In Brazil, the city of Belo Horizonte received nearly 75 mm of rain in just 20 minutes, nearly half its monthly average. Globally, fire activity during 2018 was the lowest since the start of the record in 1997, with a combined burned area of about 500 million hectares. This reinforced the long-term downward trend in fire emissions driven by changes in land use in frequently burning savannas. However, wildfires burned 3.5 million hectares across the United States, well above the 2000–10 average of 2.7 million hectares. Combined, U.S. wildfire damages for the 2017 and 2018 wildfire seasons exceeded $40 billion (U.S. dollars)

Effect of Alkali Treatment of Nettle Fibers on Oil Absorbency

Nettle is a cellulosic plant fiber with a reasonably large lumen and they are a cheap, easily renewable source of fibers with the potential for oil absorbency. To the author’s best knowledge, there are no published data available on the oil absorbency behavior of alkali-treated nettle fibers. In this work, alkali treatment on nettle fibers was carried out with a view to improve their oil absorbency. The effects of treatment time, temperature, concentration, and solid: liquor ratio of nettle fibers on oil absorbency was assessed. As compared to raw nettle fibers, the oil absorbency of alkali-treated nettle fibers was considerably higher. Nettle fibers were also characterized by FTIR, TGA, SEM, and reusability tests. Oil absorbency capacity of alkali-treated nettle fibers has also been compared with other natural materials

Hot Water Treatment on Nettle Fibers: An Environment-Friendly/Economical Process for the Production of Oil Sorbent

In this work, “green” oil sorbent was prepared from nettle fibers by hot water treatment. Effects of hot water treatment temperature, oil-sorbent contact time and reusability on oil absorbency were investigated systematically. Maximum oil absorbency of 15.89 g/g against engine oil and 13.10 g/g against diesel oil was achieved at hot water treatment temperature 100°C and oil-sorbent contact time 15 min. SEM was used to characterize the surface morphology and FTIR confirmed the chemical changes after hot water treatment. Thermal stability of the nettle fibers before and after hot water treatment was analyzed by TGA. A comparison of oil sorption capacity of nettle fibers treated with different solvents/chemicals is also presented. This work demonstrates that hot water-treated nettle fibers are an economical and eco-friendly biosorbent for oil spill removal applications