1,792 research outputs found
New Perspectives on Catalytic Hydrogen Production by the Reforming, Partial Oxidation and Decomposition of Methane and Biogas
The article provides a short review on catalyst-based processes for the production of hydrogen starting from methane, both of fossil origin and from sustainable processes. The three main paths of steam- and dry-reforming, partial oxidation and thermo-catalytic decomposition are briefly introduced and compared, above all with reference to the latest publications available and to new catalysts which obey the criteria of lower environmental impact and minimize the content of critical raw materials. The novel strategies based on chemical looping with CO2 utilization, membrane separation, electrical-assisted (plasma and microwave) processes, multistage reactors and catalyst patterning are also illustrated as the most promising perspective for CH4 reforming, especially on small and medium scale. Although these strategies should only be considered at a limited level of technological readiness, research on these topics, including catalyst development and process optimization, represents the crucial challenge for the scientific community
Neogene to Quaternary evolution of the Calabrian Subduction System, (Central Mediterranean)
We construct an ESE striking to WNW geological cross-section across the Calabrian Subduction System (Central
Mediterranean) using seismic near vertical profiles and field data. The interpreted profiles were time-to-depth
converted, merged and translated in a geological section stretching from the Marsili Oceanic Basin (Southern
Tyrrhenian Sea) to the Ionian accretionary complex . Moving toward the east, the resulting section through the
Paola, Amantea, and Crati basins, the Coastal Chain and Sila Massif and Crotone basin. The maximum elongation
of these basins change progressively moving toward the east: from NNW in the Paola to NS in the Crati to the NNE
in the Crotone basins. Data we present suggest that: Across the Calabria Tyrrhenian Continental Margin (CTCM),
top of Kabilian-Calabrian Unit (KCU) is laterally variable in depth forming basins, which are separated by major
structures with contractional or transcurrent kinematics, filled by Oligo-Miocene clastic to evaporitic deposits up to
1500m thick. Plio-Quaternary deposits display a remarkable variation in thickness from 4.5 km in the Paola Basin
to less than 400m in the central sector of the margin. Plio-Quaternary sediments are internally sub-divisible into
four sub-units (namely D1-D4) separated by tectonics enhanced angular unconformities. W-ward vergent reverse
faults with limited vertical displacement offset the top of KCU as well as the Oligo-Miocene sedimentary and evaporitic
units in the eastern side of the Paola basin. On land (Amantea \u2013 Crati) and farther to the east (Crotone basin)
below a Messinian-Pleistocene deposits the top of KCU is variable structured and covered by a Oligo-Miocene
clastic deposits with different thickness. The Plio-Quaternary deposits, unconformably overlay the Messinian and
older deposits, show the maximum thickness in the Crotone basin. Two main tectonic unconformities within the
Plio-Quaternary deposits have been recognised allowing the separation of this unit into three sub-units. In the
offshore portion of the Crotone basin, SE-ward reverse faults dissect the KCU and the Oligo-Miocene up to the
Messinian deposits. While the pre-Messinian tectonic history across the Calabrian Subduction System seems to
be quite similar, a main reorganization of the system occurring during the (?) early and (?) middle-Pliocene. Geometrical
and stratigraphic relationship show that several W-ward and E-ward vergent reverse faults in the Paola
and Crotone basins, respectively, cut and offset Messinian evaporites and older sedimentary units, controlling the
geometry of the basins. In the Paola Basin the amount of subsidence gradually increase during deposition of subunits
D2 and D3, which are probably Pliocene in age. On land, the evidence of the unconformities in the Crotone
basin indicate that Pliocene deposition occurring during the uplift of the Sila Massif. Therefore uplift of the Sila
range occurred during the strong subsidence of the Paola and Crotone basins.
The evolution of the overall structure can be then divided in two different steps: 1)the onset of subsidence started
in the Late Miocene and covered a large areas presently occupied by the Paola and Crotone basins. This basin, was
probably already separated into sub-basins but evolved in a slowly subsiding and poorly deformed area located
between the active accretionary prism and the volcanic arc. Therefore in the Middle-Upper Miocene this basin
could be defined as forearc basin. 2)In the Pliocene the structure of this large basin was fragmented due to the uplift
of a central range (Sila Massif) with an overall pop-up like structure. 3)Uplift of the belt producing subsidence
along the flanks and simultaneously formation of two distinct basins: the Paola and Crotone basins. This process
probably occurred during episodes of fast roll-back of the subducting slab, as attested by the opening of two ocean
floor basins in the back-arc region
phytotherapeutic compound yhk exerts an inhibitory effect on early stage of experimentally induced neoplastic liver lesions
The aim of this study was to investigate the effects of the herbal compound YHK on hepatocarcinogenesis induced by diethylntrosamine (DEN) in Sprague Dawley rats. Rats were randomly divided into 3 groups and followed up for 15 weeks. Groups 1 was given standard food and represented the healthy control. Liver preneoplastic foci were induced using the DEN method in groups 2 and 3 (20 rats each). However, group 3 was concomitantly given 50mg/kg/day of YHK. For quantitative assessment of liver preneoplastic foci, the placental form of glutathione-S-transferase (GST-P) positive foci were measured using immunohistochemical staining and image analysis. Treatment using DEN caused a significant decrease in body weight and increase in liver weight compared to the control group while concomitant supplementation with YHK prevented body weight loss and liver weight increase. As compared to DENonly treated rats, the group given YHK showed a significant decrease in the number, size and volume of GSTP-positive foci. Moreover, co-administration of YHK significantly reduced the incidence, number, size and volume of hepatocellular carcinoma. Anti-inflammatory, anti-fibrotic as well as antioxidative properties of this compound are mechanisms which are likely to be advocated for to explain its protective effect. It is concluded that herbal compound YHK by preventing hepatocarcinogenesis in DEN-induced liver preneoplastic lesions in rats has the potential to a large clinical application as a functional food
Foot dermatitis and productive traits in broiler chickens kept with different stocking densities, litter types and light regimen
The purpose of the research was to study the effects of high and low stocking density of broiler chickens, different types of litter and the adoption of short and long lighting regimen on broiler welfare through the evaluation of their productivity and incidence of foot pad dermatitis. 2,400 male Ross 508 were divided into 8 groups of four replicates each and reared in 32 pens according to a 3 factors experimental design of two levels each: low (LD) or high (HD) stocking density (11 and 14 birds/m2 for LD and HD respectively), chopped straw (CS) or wood shaving (WS) litters and short (SL) or long (LL) light regimens (16 h light and 8 h dark or 23 h light and 1 h dark respectively for SL and LL). Broiler growth rate and feed efficiency were positively influenced by a stocking density lower than 30 kg of live weight per m2. The adoption of a short light regimen reduced feed intake and improved feed conversion rate without modifying body live weight. Chickens reared on wood shaving litter showed a lower incidence of foot pad dermatitis
Egg quality traits of laying hens reared in organic and conventional systems.
This study aims to compare the physico-chemical properties of eggs (weight, eggshell breakingstrength, Haugh index, yolk colour, lipid, cholesterol, protein, ash and dry matter) laid either by hens reared accordingto the organic method or by caged hens kept in conventional system. More than 1,400 eggs have been analysedat the beginning, in the middle and at the end of the laying cycle in organic and conventional farms. The eggobtained from the organic system were lighter (64.4 vs 66.2 g) being yolk, albumen and eggshell weights statisticallylower in comparison with those produced in conventional system. The yolk/albumen ratio resulted lower inthe organic eggs (0.38 vs 0.39). The percentage of eggshell was not affected by the hen rearing system while theeggshell strength resulted higher in the eggs produced in the conventional system (3.265 vs 3.135 kg). The organicyolks were paler than the conventional ones. Organic eggs showed significantly higher contents of protein (17.1%vs 16.7%) and cholesterol (1.26% vs 1.21%)
Foot dermatitis and productive traits in broiler chickens kept with different stocking densities, bitter types and light regimen
The purpose of the research was to study the effects of high and low stocking density of broilerchickens, different types of litter and the adoption of short and long lighting regimen on broiler welfarethrough the evaluation of their productivity and incidence of foot pad dermatitis. 2,400 male Ross 508 weredivided into 8 groups of four replicates each and reared in 32 pens according to a 3 factors experimental designof two levels each: low (LD) or high (HD) stocking density (11 and 14 birds/m2 for LD and HD respectively),chopped straw (CS) or wood shaving (WS) litters and short (SL) or long (LL) light regimens (16 h light and 8 hdark or 23 h light and 1 h dark respectively for SL and LL). Broiler growth rate and feed efficiency were positivelyinfluenced by a stocking density lower than 30 kg of live weight per m2. The adoption of a short light regimenreduced feed intake and improved feed conversion rate without modifying body live weight. Chickensreared on wood shaving litter showed a lower incidence of foot pad dermatitis
Dietary conjugated linoleic acid supplementation of laying hen: effects on egg fatty acids composition and quality.
In order to assess the effect of dietary supplementation of conjugated linoleic acid (CLA) on fatty acid composition and egg quality, a study was carried out on three groups of laying hens, each of 9 subjects, fed diets supplemented with 0, 1.25 and 2.5% CLA. Increasing CLA concentration in diet, yolk CLA concentration increased from 0.15 (Control) to 6.04 and 11.73 mg/kg (CLA 1.25 and CLA 2.50, respectively). The most representative isomer was cis-9, trans-11. The saturated fatty and monounsaturated fatty acid in yolk increased and decreased, respectively, with CLA supplementation. Egg yield and quality traits did not show any significant difference among groups
Oxidative Stability And Quality Traits Of n-3 Pufa Enriched Chicken Meat
A total of 360 broilers, female Cobb 500, were fed from 21 d to slaughter (46 d) a commercial diet supplemented with 0, 0.5 or 1% Schizochitrium sp. marine algae, as dietary source of n-3 PUFA. Meat with the highest n-3 PUFA content showed a reduced lipid stability, particularly in breast, while the organoleptic properties evaluated in drumsticks were not affected by the dietary treatment. Breast colour was deeper in the group receiving the highest algal supplementation
oxidative stability and sensory and functional properties of eggs from laying hens fed supranutritional doses of vitamins e and c
Abstract This study evaluated the effects of two dietary doses of vitamins E and C supplemented separately and together, on the content of vitamin E in the yolk, on the lipid stability of fresh and stored eggs, and on their sensory and functional properties. Hy-Line Brown hens (n = 216) received a basal diet for 8 wk supplemented with 100 or 200 mg DL-alpha-tocopheryl acetate (E100 or E200, respectively)/kg, 500 or 1,000 mg ascorbic acid (C500 and C1000, respectively)/kg, or 100 mg DL-alpha-tocopheryl acetate plus 500 mg ascorbic acid (E100+C500)/kg, whereas the control group received no supplementation. Fresh eggs and eggs stored 30,60, and 90 d at 4 C or stored 28 d at room temperature were analyzed for vitamin E content and TBA-reactive substances (TBARS). We also evaluated functional properties of fresh and cooked eggs and sensory properties of boiled and scrambled eggs. The yolk content of vitamin E depended on the level of dietary addition and decreased after 90 d of storage at 4 C or after 28 d at 25 C. Vitamin supplementation had no effect on fresh or refrigerated eggs, whereas 4 wk of storage at room temperature increased TBARS in the control and the group supplemented with the highest doses of vitamins. Ascorbic acid improved Haugh units and elasticity of albumen gels, whereas cohesiveness and hardness of yolk, albumen and whole-egg gels were not affected by dietary treatment. Panelists were not able to distinguish treated eggs from control eggs
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