Real-Gas Effects and Phase Separation in Underexpanded Jets at Engine-Relevant Conditions

A numerical framework implemented in the open-source tool OpenFOAM is presented in this work combining a hybrid, pressure-based solver with a vapor-liquid equilibrium model based on the cubic equation of state. This framework is used in the present work to investigate underexpanded jets at engine-relevant conditions where real-gas effects and mixture induced phase separation are probable to occur. A thorough validation and discussion of the applied vapor-liquid equilibrium model is conducted by means of general thermodynamic relations and measurement data available in the literature. Engine-relevant simulation cases for two different fuels were defined. Analyses of the flow field show that the used fuel has a first order effect on the occurrence of phase separation. In the case of phase separation two different effects could be revealed causing the single-phase instability, namely the strong expansion and the mixing of the fuel with the chamber gas. A comparison of single-phase and two-phase jets disclosed that the phase separation leads to a completely different penetration depth in contrast to single-phase injection and therefore commonly used analytical approaches fail to predict the penetration depth.Comment: Preprint submitted to AIAA Scitech 2018, Kissimmee, Florid

Tear fluid biomarkers in ocular and systemic disease: potential use for predictive, preventive and personalised medicine

In the field of predictive, preventive and personalised medicine, researchers are keen to identify novel and reliable ways to predict and diagnose disease, as well as to monitor patient response to therapeutic agents. In the last decade alone, the sensitivity of profiling technologies has undergone huge improvements in detection sensitivity, thus allowing quantification of minute samples, for example body fluids that were previously difficult to assay. As a consequence, there has been a huge increase in tear fluid investigation, predominantly in the field of ocular surface disease. As tears are a more accessible and less complex body fluid (than serum or plasma) and sampling is much less invasive, research is starting to focus on how disease processes affect the proteomic, lipidomic and metabolomic composition of the tear film. By determining compositional changes to tear profiles, crucial pathways in disease progression may be identified, allowing for more predictive and personalised therapy of the individual. This article will provide an overview of the various putative tear fluid biomarkers that have been identified to date, ranging from ocular surface disease and retinopathies to cancer and multiple sclerosis. Putative tear fluid biomarkers of ocular disorders, as well as the more recent field of systemic disease biomarkers, will be shown

Synthesis and Characterization of Chitosan-Citrate Microparticle Using Ionic Gelation Methods

A study has been conducted aimed to synthesize chitosan-citrate using the ionic gelation method and its characterization with FTIR, SEM, SAA, and PSA, as well as solubility and swelling tests. The results showed that chitosan reacted with sodium citrate producing chitosan-citrate particles. The product of chitosan-citrate has a rough and thickened surface morphology. Surface area is obtained by 35.233 m2/g and pore size is 0.027 cc/g, smaller than chitosan. Based on solubility and swelling tests in acidic, alkaline, and neutral media, chitosan-citrate has good resistance and low swelling effect

Synthesis and Characterization of Activated Carbon from Waste Compedak Fruit (Artocarpus Champeden) Activated H3PO4 as Adsorbent of Methylene Blue

Synthesis of activated carbon from cempedak peel waste is carried out to utilize biomass waste. This study aimed to synthesize and characterize activated carbon from cempedak peel waste. The synthesis was carried out by chemical activation using phosphoric acid with a dry impregnation ratio of 1:4 (g sample:g H3PO4). Samples impregnated for 24 hours were then heated at 250℃—and then calcined at 350℃ and 450℃. The XRD and FTIR characterization results indicated that the activated carbon obtained had an amorphous structure and the activated carbon obtained had hydroxyl, carbonyl, and carboxylic groups. Activated carbon with the highest yield was obtained at a temperature of 350, namely 43%. The results of determining the water content of activated carbon obtained are 8.36% at 350 0C and 7.1% at 450 ℃. The value of water content and ash content of activated carbon from the skin of this cempedak fruit has met the Indonesian National Standard (SNI 06-3730-1995). The best-activated carbon yield was at a calcination temperature of 450, with the percentage of adsorption efficiency on methylene blue of 98.88%

Isolation of Carrageenan from Eucheuma cottonii by Variying Alkaline Solutions

The carrageenan can be isolated by combining alkaline KOH, NaOH, and Ca(OH)2 solutions. Alkaline solutions of KOH: NaOH, KOH: Ca(OH)2, and NaOH: Ca(OH)2 were combined to extract carrageenan. The amount of the solution was varied, the carrageenan groups were characterized using FTIR, and the carrageenan’s gel strength was tested. The extraction results obtained the highest yield in the combination of alkaline solutions Ca(OH)2 80%+KOH 20%, which is equal to 70.18% FTIR test results for carrageenan produced from the extraction of Eucheuma cottonii seaweed showed absorption showing the type of kappa (κ) carrageenan. The highest gel strength test results were obtained in an alkaline solution of Ca(OH)2 80%: NaOH 20%, which was 252.5 g bloom, and the lowest was made in a solution of Ca(OH)2 80%: KOH 20%, which was 21.0 g bloom

Ekstraksi Dan Karakterisasi Kitosan Dari Kulit Udang Windu (Penaeus monodon) Serta Proses Depolimerisasi Kitosan Dengan Hidrogen Peroksida Berdasarkan Variasi Suhu Pemanasan

An extraction of chitin from shell of the tiger shrimp (Penaeus monodon), a convertion chitin into chitosan and depolymerization chitosan into oligochitosan using hydrogen peroxide based on variations in heating temperature have been done. Chitosan had depolymerized and it’s molecular weight had tested by end group analysis method and it’s degree of deacetylation had tested by UV-Vis spectrophotometry method. Oligochitosan had obtained from the conversion of chitin is isolated from the shell of tiger shrimp and from commercial chitin. The content of chitin obtained in tiger shrimp shells was 35.90% while the result of the conversion of commercial chitin into chitosan amounted to 62.33%.  Characterization of functional groups using FTIR spectrophotometry showed that the conversion of chitosan from chitin commercial have absorption bands of 3617.56 (OH), 3050.47 - 3127.63 (-NH stretching), 2894.24 (-CH methylene), 1679.06 (-C = O), 1564.30 (-NH bending), and 1076.30 cm-1 (-CO-). The commercial chitosan which is characterized by FTIR spectrophotometric method also supports the results of the conversion of chitosan from chitin commercial.  In the process of depolymerization of chitosan by hydrogen peroxide was found that the greater heating temperature was used, the smaller the percent yield and molecular weight of oligochitosan were at 40 oC, 50 oC, 60 oC and 70 oC gained weight average molecular oligochitosan were 1030.12 g/mol, 1019, 28 g/mol, 978.12 g/mol, and 908.82 g/mol, respectivel

Ekstraksi Dan Karakterisasi Kitosan Dari Kulit Udang Windu (Penaeus monodon) Serta Proses Depolimerisasi Kitosan Dengan Hidrogen Peroksida Berdasarkan Variasi Suhu Pemanasan

An extraction of chitin from shell of the tiger shrimp (Penaeus monodon), a convertion chitin into chitosan and depolymerization chitosan into oligochitosan using hydrogen peroxide based on variations in heating temperature have been done. Chitosan had depolymerized and it’s molecular weight had tested by end group analysis method and it’s degree of deacetylation had tested by UV-Vis spectrophotometry method. Oligochitosan had obtained from the conversion of chitin is isolated from the shell of tiger shrimp and from commercial chitin. The content of chitin obtained in tiger shrimp shells was 35.90% while the result of the conversion of commercial chitin into chitosan amounted to 62.33%.  Characterization of functional groups using FTIR spectrophotometry showed that the conversion of chitosan from chitin commercial have absorption bands of 3617.56 (OH), 3050.47 - 3127.63 (-NH stretching), 2894.24 (-CH methylene), 1679.06 (-C = O), 1564.30 (-NH bending), and 1076.30 cm-1 (-CO-). The commercial chitosan which is characterized by FTIR spectrophotometric method also supports the results of the conversion of chitosan from chitin commercial.  In the process of depolymerization of chitosan by hydrogen peroxide was found that the greater heating temperature was used, the smaller the percent yield and molecular weight of oligochitosan were at 40 oC, 50 oC, 60 oC and 70 oC gained weight average molecular oligochitosan were 1030.12 g/mol, 1019, 28 g/mol, 978.12 g/mol, and 908.82 g/mol, respectivel

CHARACTERISATION OF ACTIVATED CARBON FROM WHITE SNAPPER SCALES (Lates calcarife) WASTE

ABSTRACT               Research on the characterisation of activated carbon of white snapper (Lates calcarifer) scales waste, obtained through carbonisation process, fish scales were put in a furnace at 350 oC for 2 hours. Then cooled and sieved with a 100 mesh sieve, characterised by XRD, resulting in three peaks with the strongest intensity at 2θ regions of 26.45o, 32.69o, and 33.60o respectively. The surface acidity of carbon solids before and after activation were (4.48x10-3 and 7.77x10-3) mol/g, respectively. The activation process of white snapper scales (Lates calcarifer), increases the surface area of carbon can react with other chemicals. Subsequently, it was calcined at 450 oC under vacuum conditions for 2 hours with N2 gas, and characterised by XRD. The results showed a shift in 2θ peaks of 26.52o, 29.66o, and 32.77o, respectively. The carbon was activated by soaking with 3 M KOH activator for 15 hours, washed with distilled water, and dried in an oven at 110°C for 1 hour, characterised by XRD, and the peaks with the strongest intensity were obtained at 26.22°C, 29.12°C, and 32.43°C, with increasing basal spacing.   Keywords: activated carbon, white snapper scales, XR

Tumor growth suppression induced by biomimetic silk fibroin hydrogels

Protein-based hydrogels with distinct conformations which enable encapsulation or differentiation of cells are of great interest in 3D cancer research models. Conformational changes may cause macroscopic shifts in the hydrogels, allowing for its use as biosensors and drug carriers. In depth knowledge on how 3D conformational changes in proteins may affect cell fate and tumor formation is required. Thus, this study reports an enzymatically crosslinked silk fibroin (SF) hydrogel system that can undergo intrinsic conformation changes from random coil to β-sheet conformation. In random coil status, the SF hydrogels are transparent, elastic, and present ionic strength and pH stimuli-responses. The random coil hydrogels become β-sheet conformation after 10 days in vitro incubation and 14 days in vivo subcutaneous implantation in rat. When encapsulated with ATDC-5 cells, the random coil SF hydrogel promotes cell survival up to 7 days, whereas the subsequent β-sheet transition induces cell apoptosis in vitro. HeLa cells are further incorporated in SF hydrogels and the constructs are investigated in vitro and in an in vivo chick chorioallantoic membrane model for tumor formation. In vivo, Angiogenesis and tumor formation are suppressed in SF hydrogels. Therefore, these hydrogels provide new insights for cancer research and uses of biomaterials.The authors would like to thank the Portuguese Foundation for Science and Technology (FCT) project grants OsteoCart (PTDC/CTM-BPC/115977/2009) and Tissue2Tissue (PTDC/CTM/105703/2008) which supported this study. Research leading to these results has also received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement no REGPOT-CT2012-316331-POLARIS. Le-Ping Yan was awarded a PhD scholarship from FCT (SFRH/BD/64717/2009). We also would like to thank FCT for the distinction attributed to J.M. Oliveira under the Investigador FCT program (IF/00423/2012). The authors also like to acknowledge Dr. Mariana B. Oliveira for technical assistance on the dynamic mechanical analysis of the cell-laden hydrogels

Ekstraksi Dan Karakterisasi Kitosan Dari Kulit Udang Windu (Penaeus monodon) Serta Proses Depolimerisasi Kitosan Dengan Hidrogen Peroksida Berdasarkan Variasi Suhu Pemanasan

An extraction of chitin from shell of the tiger shrimp (Penaeus monodon), a convertion chitin into chitosan and depolymerization chitosan into oligochitosan using hydrogen peroxide based on variations in heating temperature have been done. Chitosan had depolymerized and it’s molecular weight had tested by end group analysis method and it’s degree of deacetylation had tested by UV-Vis spectrophotometry method. Oligochitosan had obtained from the conversion of chitin is isolated from the shell of tiger shrimp and from commercial chitin. The content of chitin obtained in tiger shrimp shells was 35.90% while the result of the conversion of commercial chitin into chitosan amounted to 62.33%.  Characterization of functional groups using FTIR spectrophotometry showed that the conversion of chitosan from chitin commercial have absorption bands of 3617.56 (OH), 3050.47 - 3127.63 (-NH stretching), 2894.24 (-CH methylene), 1679.06 (-C = O), 1564.30 (-NH bending), and 1076.30 cm-1 (-CO-). The commercial chitosan which is characterized by FTIR spectrophotometric method also supports the results of the conversion of chitosan from chitin commercial.  In the process of depolymerization of chitosan by hydrogen peroxide was found that the greater heating temperature was used, the smaller the percent yield and molecular weight of oligochitosan were at 40 oC, 50 oC, 60 oC and 70 oC gained weight average molecular oligochitosan were 1030.12 g/mol, 1019, 28 g/mol, 978.12 g/mol, and 908.82 g/mol, respectivel