scholarly journals Gizzard vs. teeth, it's a tie: food-processing efficiency in herbivorous birds and mammals and implications for dinosaur feeding strategies

Paleobiology ◽  
2011 ◽  
Vol 37 (4) ◽  
pp. 577-586 ◽  
Author(s):  
Julia Fritz ◽  
Jürgen Hummel ◽  
Ellen Kienzle ◽  
Oliver Wings ◽  
W. Jürgen Streich ◽  
...  

Particle size reduction is a primary means of improving efficiency in herbivores. The mode of food particle size reduction is one of the main differences between herbivorous birds (gizzard) and mammals (teeth). For a quantitative comparison of the efficiency of food comminution, we investigated mean fecal particle sizes (MPS) in 14 herbivorous bird species and compared these with a data set of 111 non-ruminant herbivorous mammal species. In general MPS increased with body mass, but there was no significant difference between birds and mammals, suggesting a comparable efficiency of food processing by gizzards and chewing teeth. The results lead to the intriguing question of why gizzard systems have evolved comparatively rarely among amniote herbivores. Advantages linked to one of the two food comminution systems must, however, be sought in different effects other than size reduction itself. In paleoecological scenarios, the evolution of “dental batteries,” for example in ornithopod dinosaurs, should be considered an advantage compared to absence of mastication, but not compared to gizzard-based herbivory.

Author(s):  
Yang Yang ◽  
Timothy Deines ◽  
Meng Zhang ◽  
Ke Zhang ◽  
Donghai Wang

Biofuel derived from cellulosic biomass is a sustainable alternative to petroleum-based fuel. Pretreatment is an essential step in biofuel production because it accounts for more than 20% of the inputs. Furthermore, particle size reduction as a preprocessing step prior to pretreatment exerts a substantial impact on all following processes. Many studies have investigated the effects of biomass particle size on sugar yield after conventional pretreatments of biomass such as alkaline and dilute acid pretreatments. The similar trends have shown that smaller biomass particle size results in higher sugar yield. Supercritical CO2 (SC-CO2) pretreatment has been applied at 1450 psi, 120 °C for 30 mins in this study as a pretreatment method for biofuel production from cellulosic biomass. As a recyclable green-chemistry method, SC-CO2 pretreatment offers many advantages such as no toxic chemicals added and low-cost input. The objective of this study is to understand the effects of particle size on sugar yield after SC-CO2 pretreatment. Three particle size: 1 mm, 2 mm, and 4 mm were used for size reduction of corn stover. Ethanol and water were used as co-solvents to enhance SC-CO2 pretreatment. Analysis of variance (ANOVA) was performed and it is found that, after SC-CO2 pretreatment, the sugar yields differ significantly between 1 mm and 2 mm, 1 mm and 4 mm. In contrast, there is no significant difference between 2 mm and 4 mm after SC-CO2 pretreatment. 1 mm particle produced the highest sugar yield of 0.115 g glucose per 1 g of dry biomass which is 16.62% and 10.39% higher than the 4 mm and 2 mm corn stover biomass produced.


2018 ◽  
Vol 60 (1) ◽  
pp. 42-45
Author(s):  
Tuan Quang Nguyen ◽  
Van Lam Nguyen ◽  
Thai Son Nguyen ◽  
Thi Minh Hue Pham ◽  
◽  
...  

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 971
Author(s):  
Oktawian Bialas ◽  
Mateusz Lis ◽  
Anna Woźniak ◽  
Marcin Adamiak

This paper analyses the possibility of obtaining surface-infused nano gold particles with the polyether ether ketone (PEEK) using picosecond laser treatment. To fuse particles into polymer, the raw surface of PEEK was sputtered with 99.99% Au and micromachined by an A-355 laser device for gold particle size reduction. Biomimetic pattern and parameters optimization were key properties of the design for biomedical application. The structures were investigated by employing surface topography in the presence of micron and sub-micron features. The energy of the laser beam stating the presence of polymer bond thermalisation with remelting due to high temperature was also taken into the account. The process was suited to avoid intensive surface modification that could compromise the mechanical properties of fragile cardiovascular devices. The initial material analysis was conducted by power–depth dependence using confocal microscopy. The evaluation of gold particle size reduction was performed with scanning electron microscopy (SEM), secondary electron (SE) and quadrant backscatter electron detector (QBSD) and energy dispersive spectroscopy (EDS) analysis. The visibility of the constituted coating was checked by a commercial grade X-ray that is commonly used in hospitals. Attempts to reduce deposited gold coating to the size of Au nanoparticles (Au NPs) and to fuse them into the groove using a laser beam have been successfully completed. The relationship between the laser power and the characteristics of the particles remaining in the laser irradiation area has been established. A significant increase in quantity was achieved using laser power with a minimum power of 15 mW. The obtained results allowed for the continuation of the pilot study for augmented research and material properties analysis.


Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2856
Author(s):  
Gary B. Smejkal ◽  
Edmund Y. Ting ◽  
Karthik Nambi Arul Nambi ◽  
Richard T. Schumacher ◽  
Alexander V. Lazarev

Stable, oil-in-water nanoemulsions containing astaxanthin (AsX) were produced by intense fluid shear forces resulting from pumping a coarse reagent emulsion through a self-throttling annular gap valve at 300 MPa. Compared to crude emulsions prepared by conventional homogenization, a size reduction of over two orders of magnitude was observed for AsX-encapsulated oil droplets following just one pass through the annular valve. In krill oil formulations, the mean hydrodynamic diameter of lipid particles was reduced to 60 nm after only two passes through the valve and reached a minimal size of 24 nm after eight passes. Repeated processing of samples through the valve progressively decreased lipid particle size, with an inflection in the rate of particle size reduction generally observed after 2–4 passes. Krill- and argan oil-based nanoemulsions were produced using an Ultra Shear Technology™ (UST™) approach and characterized in terms of their small particle size, low polydispersity, and stability.


Crystals ◽  
2018 ◽  
Vol 8 (6) ◽  
pp. 249 ◽  
Author(s):  
Zhen-Yu Yang ◽  
Shih-Kuo Yen ◽  
Wei-Syun Hu ◽  
Yu-Zhe Huang ◽  
Tsung-Mao Yang ◽  
...  

1996 ◽  
Vol 18 (2) ◽  
pp. 121-125 ◽  
Author(s):  
M.P. Nandakumar ◽  
M.S. Thakur ◽  
K.S.M.S. Raghavarao ◽  
N.P. Ghildyal

Author(s):  
Rahul Kumar ◽  
Sanjay Kumar ◽  
Pranava Chaudhari ◽  
Amit K. Thakur

Abstract Flufenamic acid (FFA) is a Biopharmaceutical Classification System- II (BCS-II) class drug with poor bioavailability and a lower dissolution rate. Particle size reduction is one of the conventional approaches to increase the dissolution rate and subsequently the bioavailability. The use of the liquid antisolvent method for particle size reduction of FFA was studied in this work. Ethanol and water were used as solvent and antisolvent, respectively. Experimental parameters such as solution concentration (10–40 mg/ml), flow rate (120–480 ml/h), temperature (298–328 K) and stirring speed (200–800 rpm) were investigated. Furthermore, the solid dispersion of FFA was prepared with polyvinylpyrrolidone K-30 (PVP K-30) with different weight ratios (1:1, 1:2, 1:3 and 1:4) and samples were characterized using SEM, FTIR and XRD techniques. The experimental investigation revealed that higher values of concentration, injection rate, stirring speed, along with lower temperature favored the formation of fine particles. SEM analysis revealed that the morphology of raw FFA changed from rock-like to rectangular-like after liquid antisolvent recrystallization. FTIR analysis validated the presence of hydrogen bonding between FFA and PVP in solid dispersion. XRD analysis showed no significant change in the crystallinity of the processed FFA.


Sign in / Sign up

Export Citation Format

Share Document