Synthesis and characterization of chitosan/montmorillonite nanocomposites for application as edible coating

Edible coating can improve fruits shelf life and, consequently, reduce their waste. Chitosan, which presents a potential for chemical modifications and capacity to form films, can be an alternative for coating due to its biocompatibility, biodegradability, and antimicrobial properties. Chitosan film can be obtained through casting method presenting suitable mechanical properties, such as resistance to traction and elongation, ability to adhere to surfaces and selective permeability to gases, such as O2 and CO2. However, it is highly permeable to water vapor, which can limit its potential coating use. The properties of chitosan films can be improved through the formation of composites by inserting nanoclays as montmorillonite in the polymeric matrix. The objective of this study was to develop and characterize chitosan/montmorillonite nanocomposites for fruit coating aiming for future applications in the field of smart packaging. Nanocomposites were characterized by its microstructure, thermal, mechanical, and physicochemical properties. X-ray diffraction analysis indicated changes in crystallinity with the insertion of montmorillonite. Nanocomposites became more transparent and significantly reduced its water permeability rate with 0.5% w/w montmorillonite addition. Elastic rigidity and tensile strength of the films were improved. Chitosan/montmorillonite nanocomposites demonstrated the potential to improve the storage time of Williams pears.

A study of fungicidal and anti-phenol oxidase activity of some α-amino phosphonate derivatives

Background Developing new pesticides with multi-function may be a suitable strategy to save time and cost and reduce the emergence of resistant strains of pests and pathogens. The organophosphorus derivatives have not been widely used in agriculture as fungicides. In this work, a series of six α-amino phosphonate derivatives were prepared and tested for their fungicidal and anti-phenol oxidase activities. Results The prepared compounds revealed a promising anti-fungal activity against Macrophomina phaseolina and Pythium aphanidermatum, especially M4, with MIC of 62 mg/L for M. phaseolina. M4 did not affect the fungus permeability rate of the cell membrane; however, it displayed a significant efficiency on mycelial soluble protein content. M4 and M3 with a hydroxyl group on the aniline moiety exhibited an observed anti-phenol oxidase activity. M4 inhibited the enzyme at 1 mg/mL. The DFT theoretical study revealed a significant correlation between the substituents of aniline moiety and the bioactivity of the studied compounds. The negative charge conspicuously influenced the anti-phenol oxidase activity. Conclusions Our findings suggest the studied compounds as bases to design more effective α-amino phosphonate fungicides with additional anti-phenol oxidase activity. Graphic abstract

Uncertainties in Non-Domestic Energy Performance Certificate Generating in the UK

In light of the recent launch of the Minimum Energy Efficiency Standard targeting the energy performance of commercial buildings, this study compares the energy performance certificates of three UK hotels generated by two different software, EDSL TAS and SBEM, both accredited by the UK government for the purpose. Upon finding the results discrepant, the study finds that the two software’s different assumptions for the air permeability rate contribute to the discrepancy. While modifying this value makes the results from the two software more aligned, further issues regarding the validation process arise. The study continues to find that the underlying issue can be found within the National Calculation Methodology’s assumption about domestic hot water consumption in hotels. These assumptions are compulsory to follow when generating a non-domestic energy performance certificate in the UK, therefore, any uncertainties within them can affect all the buildings seeking an energy performance certificate within that sector. Finally, the study discusses that, for meeting the carbon dioxide mitigation goals, it is necessary to make changes to the current procedure of energy performance certificate generating in the UK to increase its reliability.

Avaliação das taxas de permeabilidade intra-lote auxiliada por imagens de RPA

The urbanization process of the municipality of Irati-PR occurred in an intense and accelerated way, being unavoidable the ground waterproofing through buildings, pavements of the streets, walks and patios. Due to this process, several factors of the natural environment are modified, for example, the soil reduces the infiltration capacity, implying an increase in the surface runoff rate and its velocity, contributing significantly to floods occurrence. Therefore, the work objective is to evaluate the urban environmental quality in a neighborhood of the Irati city, Paraná State, using very high spatial resolution images. The vectorization technique on screen allows mapping the permeable areas within the lots and estimating in square kilometers their occupation. With the percentage of permeability, the comparison with the minimum permeability rate required by municipal legislation can be carried out. The study result showed that of the 82 lots analyzed, 47.56% are irregular with the legislation. Through the results obtained, the conditions of each court were evaluated concerning the confrontation with the current legislation.

Transhepatic venous access for hemodialysis-single centre expirience

Introduction. A percutaneous transhepatic approach has been used to place tunneled catheters in the inferior vena cava for hemodialysis. This route through the suprahepatic vein could be used to place a tunnelled catheter for permanent haemodialysis without complications and with an excellent permeability rate. Single centre expirience. From 2011 to 2020 in a Military Medical Academy we treated 4 patients with transhepatic central venous catheter for hemodialysis. All of them had exhausted approaches during period of hemodialysis. Arterio-venous fistulas had been thrombosed on the arms, thrombosis subclavian vein billateraly or superior cava veinand complications by femoral catheters was present. Peritoneal dialysis was not possible. Discusion. Limited number of papers descripted outcome of placement transhepatic catheters for hemodialysis. In our expirience one patient needed scroll catheter due hemodialysis had not well outcome, and one patient needed thrombolysis catheter.Two of them are on hemodialysis without complications for 300 and 1650 days. Conclusion. The transhepatic venous access under ultrasound and radioscopic guidance is a simple and safe method. It is an acceptable alternative for permanent haemodialysis catheters when other venous accesses are exhausted, and when it is performed by a well-trained team.

CHANGES IN SOIL PHYSICAL CHARACTERISTICS ON THE SOIL CRUST PROCESS THROUGH THE USE OF CHICKEN MANURE AND POLYACRYLE AMIDE UNDER INTENSE RAINFALL

Soil crust is a soil suface layer which is more compact, harder, and brittle when it is drier than underlaying material. The soil physical characteristics such as aggregate stability, bulk density and soil permeability rate are closely related to this soil crust process. An experiment was conducted to evaluate the effects of chicken manure doses and certain chicken manure with PAM (Polyacrile Amide) to soil aggregate, bulk density and soil permeability rate. The result of this research, were: 1) An incremental addition of chicken manure into soil increased soil aggregation percentage, soil stability and soil permeability rate, and 2) The combined incremental additions of chicken manure with PAM were found to be more effective than only an incremental additions of chicken manure, increasing the aggregation percentage, soil aggregate stability, from the soil one day drainage process, but another case in decreasing the bulk density permeability rate from the soil with the same process.

Experimental Research on the Properties of Rock-Filled Concrete

In order to comprehensively evaluate the properties of rock-filled concrete (RFC) with the strength of C15, lab experimental test and in-situ test are applied to explore the mechanical, hydraulic, ultrasonic characteristics of RFC in Hantang reservoir dam. Four types of defects within RFC are shown from the appearance of borehole cores specimens: (1) large sized voids existing in interfacial transition zone (ITZ) between self-compacting concrete (SCC) and rock block (RB); (2) bad cohesion in ITZ; (3) joints within rock block; (4) voids within SCC. For hydraulic aspects, the average porosity of RFC is 14.10%; the permeability rate of RFC ranges from 2.41 Lu to 10.41 Lu, with the average of 11.32 Lu, occasionally more than 25.52 Lu due to interconnected defects. For ultrasonic aspects, the ultrasonic velocity of RFC conforms to lognormal distribution, with the average of 2993.3 m/s and standard deviation of 650.5 m/s. For mechanical aspects, the average cubic compressive strength of RFC is 22.55 Mpa, with the standard deviation of 4.09 Mp. Thus the data shows a relatively great dispersion due to uneven distribution of some defects in RFC, which deteriorate the quality of RFC. Through the experimental investigation, it is shown that the quality of massive RFC in the Hantang dam is obviously non-homogeneous, mainly influenced by construction technology.

APLIKASI DAN KARAKTERISASI EDIBLE FILM DARI KARAGINAN (Eucheuma cottonii) PADA BUAH

Fruits are perisbable comestible that having short shelf life. The disadvantage of fruits since post harvest to received by consumers in quantity and quality is caused by microorganisms, insect, and the conditions of distribution and storage. Carrageenan edible film packaging is one of proper alternative to increase endurance and shelf life of fruits. It also becoe a solutio for undegradable plastic packaging that causing environmental pollution. Characterization which is common being conducted to edible film are mechanic properties (tensile strength and elongation break), thickness, solubility, water and vapor permeability rate. Several studies show that fruits with carragenan edible film and coating increase the perishable significanly comparing to uncoated fruits (control), so that it could lengthen the shelf life, reduce disappear of the odor,slow down colour change and gase transfer.