Thick Paste Research Articles

Quality Control of Thick Film Hybrid Integrated Circuit Process Design and Manufacturing

With the continuous upgrading of the technological content of electronic products, higher requirements have been put forward for the manufacturing process of thick film hybrid integrated circuits, resulting in the manufacturing process of thick film hybrid integrated circuits. Thick-film hybrid integrated circuits are an important realization method of microelectronic components. They are widely used in many fields such as civil, military, and aerospace satellites. An important reason is that the thick film process has a super high cost performance compared with other process realization methods. Thick film conductive paste is the most core material in the thick film process. Its interconnection performance such as sintering and welding directly affects the performance of the finished thick film components. Therefore, the thick film conductive paste interconnection under specific process conditions is evaluated. Related performance is crucial. In the mass production process of thick film hybrid integrated circuits, it is particularly important to control the quality and increase the product growth rate. This paper introduces the description of the quality management of the rear-film hybrid integrated circuit production line in the aspects of thick-film hybrid integrated circuit quality system construction, raw material procurement, supplier management, project quality management, on-site management, etc. The manufacturing process of the back-film hybrid integrated circuit briefly introduced has stable performance, high reliability and wide application fields in terms of manufacturing characteristics. Studies have shown that the manufacturing process is suitable for mass automated production, and has the advantages of simple process, low investment, and quick results.

Low-Cost Purification of Metallurgical Silicon for Photovoltaic Application.(Dept.E)

A new, simple, low-cost technique for the preparation of solar-grade silicon, based on acid-treatment and high-temperature phosphorus-pentoxide gettering of metallurgical-grade silicon for removing the harmful metallic impurities is reported. The starting material is pulverized metallurgical-grade silicon. Purification is achieved by continuously boiling the silicon in a mixture of acids under reflux conditions for about 14 days, replacing the acid by a fresh mixture every 3-5 days. Iron content in the silicon and in the extracted acids has determined using & spectrophotometric technique. Acid leaching was found to be affective in appreciably reducing the content of harmful metallic impurities. Gettering with phosphorus pentoxide was used to achieve further purification of the acid-treated silicon. A thick paste of the acid-leached silicon 5% by weight of phosphorus pentoxide and de-ionized water was heated at 1050 oC for 4 days in a clean quartz container in air. The resulting charge was treated with hydroflouric acid to remove the phosphosilicate glass, and then cleaned and refluxed with agua regia for several days. The iron content in the silicon was further reduced to 150 - 250 ppm. The acid-leached and gettered silicon was used to produce a large area substrate using melting and unidirectional solidification, for solar cell fabrication. The substrate had a resistivity of 0.03 Ԛ c.m and was n-type, making it very suitable for solar cell fabrication.

Nutritional characteristics and phytochemical screening of traditional panai (Borassus flabellifer) olai kozhukattai

Panai Olai Kozhukattai (POK) or simply palm leaf dumpling is a traditional south Indian delicacy which is very much popular in Tamil Nadu, India. POK preparation by traditional methods involves mixing all the ingredients to form a thick paste, which is then wrapped in tender palm leaf strips and cooked using steam under pressure. The present paper is the first-ever attempt on studying the nutritional characteristics of POK. MATERIAL AND METHODS: The nutritional analysis of POK involves proximate analysis, and vitamin and mineral composition. RESULTS: The proximate analysis results demonstrated that POK is nutritionally predominant over the other South Indian breakfast foods. High levels of fat-soluble vitamins were present in POK. Water-soluble vitamins including niacin, pyridoxine, thiamine, and riboflavin were found in POK and with a high percentage of riboflavin. Among the mineral elements analyzed, the concentration of potassium in POK sample was the highest followed by magnesium, phosphorous, manganese, zinc, iron, and selenium. The study also documented a protocol of POK preparation. It is believed that the steaming in the palm leaves gives the palm leaf flavor to POK and it also transfers phytonutrients into the product from the palm leaves. Hence, the paper also focuses on investigating the presence of essential bioactive compounds in POK using qualitative phytochemical tests. The phytochemical screening of methanol extracts of POK revealed the presence of certain phytochemicals such as flavonoids, alkaloids, glycosides, and saponins and total flavonoid content of POK was estimated to be 148.25 mg/100 g. CONCLUSION: Overall, the study leads to the documentation of a preparation protocol along with the nutritional and phytochemical aspects of traditional POK with a view to promoting its consumption in other parts of the world.

Characterization of the expansion due to the delayed ettringite formation at the cement paste-aggregate interface

Delayed Ettringite Formation (DEF), is one of the different Internal Sulfate Attack (ISA), is a slow chemical reaction that can be responsible for the degradation of cementitious materials, through the swelling of the material followed by crack diffusion in the structure. The objective of this study is the experimental characterization at the local scale (10 x 10 x 30 mm3 samples) of the concrete reached by DEF. The composite samples, consist of a 15 mm thick cement paste placed in contact with a siliceous aggregate. The shape of these samples makes it possible to study the mechanical behavior of the interface between the cement paste and the aggregate. This zone is identified as a privileged zone of the development of DEF. Given the slowness of this pathology, the experimental setting in the laboratory is accelerated by choosing conditions favoring the appearance of DEF. The tests are exploited at the local scale by measuring expansions by image correlation of the degraded samples and by scanning electron microscope observations. The results showed a higher expansion at the cement paste-aggregate interface compared to the cement paste. A tensile test performed at local scale allowed to characterize the impact of DEF on mechanical properties of the cement paste-aggregate interface. A drop in strength was observed with heterogeneous formation and localization of ettringite inside the interface.

A Novel Method to Fabricate a Thick-Film Cu Electrode Fired in Air Through Printing Al Electrode and Reduction-Oxidation Substitution Reaction

The thick-film conductor pastes that are applied most widely are Ag and Cu due to their high conductivity. Ag paste can be sintered in air to have high conductivity, but its disadvantage is the overly high cost. Contrarily, although Cu thick paste is not expensive in terms of materials, Cu thick-film paste must be sintered in a reducing atmosphere to obtain high conductivity, which leads to high processing costs. A novel method for fabricating the base metal electrode Cu in an air atmosphere for high-temperature firing was successfully developed based on thick-film screen-printing Al pastes utilizing a reduction-oxidation substitution reaction. To make an excellent Cu electrode that can be substituted for a thick-film Al electrode, Al paste with high solid content, a large Al powder particle size, a CuSO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> solution with low pH, high temperature, and proper soaking time are all positive parameters. The first thick-film screen-printing Cu electrode with high conductivity ( > 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-6 </sup> Ω), which is comparable with a thick-film Ag electrode, was successfully fabricated in air firing instead of reducing atmosphere firing.

Feasibility study on co-pyrolyzation of microplastic extraction in conventional sewage sludge for the cementitious application

Numbers of research discovered the contamination of microplastics [MPs] in the wastewater. It is estimated the amount of sludge waste will increase by 9.1% per year. It is beneficial if the sewage sludge can be turned in to useful products. In this research, the objective is to study the suitability of sewage sludge containing MPs as a cementitious material and to identify the suitable temperature of the co-pyrolysis to achieve the desired characterization. The co-pyrolysis process is done by addition of 30 g of thick paste sewage sludge that has been heated at temperature 250℃ with the 67% of PET. Then, pyrolyzed at temperature 400℃, 500℃ and 600℃ to form biochar. Few analyses are performed to study the suitability of this sample as cementitious material at varies temperature such as SEM, EDX and FTIR analysis. From the SEM analysis, it can be concluded that sample of sewage sludge with the addition of PET at temperature 600℃ pyrolyzed was the best sample due to complete pore structure and highest Al, Si and Fe components are found in the sample (600˚C) using EDX. The heat flow and temperature for the sample (600˚C) are 2.86 MW and 82 ˚C respectively are higher as compared to the samples (400˚C & 500 ˚C) confirmed by DSC. The PET improves the thermal stability of biochar because it could withstand higher heat of melting and crystallization. Based on FTIR result, this biochar consists of functional group of SiO2 and SO2. In conclusion, this biochar can be categorized as highly active pozzolanic material due to SiO2 content less than 65% and Al2O3 content less than 46% and it is suitable several applications such as raw material in concrete products, feedstock in the production of cement, fill material for structural applications, and soil modification.

Blindness

Reviewed by: Blindness Theresa Smalec BLINDNESS. Based on the novel by José Sara-mago, adapted by Simon Stephens. Directed by Walter Meierjohann. Daryl Roth Theatre, New York City. April 10, 2021. I saw Blindness, the first in-person production to open in New York after the yearlong shuttering of theatres forced by COVID-19, on a spring day bustling with people. The city’s apparent normalcy made it easy to “forget” that over 10,000 residents had died of the virus in April 2020 alone, with roughly 35,000 total deaths. Walter Meierjohann’s actor-less audio play about an epidemic of blindness that turned a nation into sightless brutes was narrated by the recorded voice of British actor Juliet Stevenson (Blindness premiered in London). Stevenson recounted the contagion’s dehumanizing effects in the first person, as a character in the play: the wife of an ophthalmologist at a clinic where it began. This wife, who had also worked at the clinic, told us that patients described their blindness as a “thick paste of snowy whiteness.” Her reference to whiteness abruptly jogged my memories of the racial and economic disparities that influenced COVID-related deaths in New York City. While I hoarded toilet paper, my students in the Bronx fell ill. Some lost family. Some joined our Zoom meetings from jobs as essential workers while I taught safely from home. Contrary to New York Times critic Maya Phillips, who claimed Blindness felt “too negligent of the larger social narrative to fully translate what we experienced in the past year,” I thought the play’s multisensory plunge into the plight of a sightless nation challenged privileged audiences (tickets were $116 per pair) to recognize our complicity in the Trump administration’s blinkered, inequitable nonresponse to COVID-19. The narrator/wife was (apparently) the only character who did not lose sight during the pandemic; her resilient vision raised provocative questions about the source of her immunity. Key moments in the drama also made me wonder if others had truly gone blind, or just opted to look away. Any social commentary to grow from Blindness must start with Meierjohann’s use of space, lighting, and recorded sound. Before COVID, directors often deployed such elements to disrupt traditional theatre by staging site-specific pieces or having actors lip-sync recordings of absent others. Here, due to New York’s reopening restrictions, space, light, and sound became necessary surrogates for live performers. There was no formal stage; instead, designer Lizzie Clachan arranged pairs of seats in socially distanced rows throughout the space, where the audience sat. Some pairs of seats faced others like cars at an intersection. Aptly, this was where the action began. Stevenson, the unseen narrator to whom we listened on individual, sterilized headphones provided by the theatre, described traffic waiting for a light change. Red, orange, and green neon tubes hung above us. We saw the lights turn green, but Stephenson said that a car (which we could not see) blocked the road. Her voice shifted from calm, to puzzled, to horrified as she recalled the words the traumatized driver kept repeating when onlookers finally pulled him from his car: “I’ve gone blind!” Click for larger view View full resolution Audiences experience Blindness. (Photo: Helen Maybanks.) From there, Blindness unleashed reminders of the blatant deception and social upheaval that prevailed in 2020, slowly integrating the audience into the plot. [End Page 551] Click for larger view View full resolution Audiences experience Blindness. (Photo: Helen Maybanks.) The narrator told us that the blind man’s fiancée took him to an ophthalmologist, who determined nothing physically wrong. Yet, almost everyone with whom he interacted soon contracted the debilitating whiteness, even the eye doctor. When the latter warned of a looming pandemic, government officials countered there was no proof, no need for alarm. This scene conjured Trump’s chilling admission to Bob Woodward that he knew how serious COVID-19 was early on, but publicly minimized the risks for the sake of business as usual. As with COVID, the situation lurched from unlikely to full panic. The worried narrator confided that her husband had received a call from “The Ministry” directing him to...

Graphene Oxide "Surfactant"-Directed Tunable Concentration of Graphene Dispersion.

Homogeneous graphene dispersions with tunable concentrations are fundamental prerequisites for the preparation of graphene-based materials. Here, a strategy for effectively dispersing graphene using graphene oxide (GO) to produce homogeneous, tunable, and ultrahigh concentration graphene dispersions (>150mg mL-1 ) is proposed. The structure of GO with abundant edge-bound hydrophilic carboxyl groups and in-plane hydrophobic π-conjugated domains allows it to function as a special "surfactant" that enables graphene dispersion. In acidic solutions, GO sheets tend to form edge-to-edge hydrogen bonds and expose the π-conjugated regions which interact with graphene, thereby promoting graphene dispersion. While in alkaline solutions, GO sheets tend to stack in a surface-to-surface manner, thereby blocking the π-conjugated regions and impeding graphene dispersion. As the concentration of GO-dispersed graphene dispersion (GO/G) increases, a continuous transition between four states is obtained, including a dilute dispersion, a thick paste, a free-standing gel, and a kneadable, playdough-like material. Furthermore, GO/G can be applied to create desirable structures including highly conductive graphene films with excellent flexibility, thereby demonstrating an immense potential in flexible composite materials.

The microbiology of Greek/Cyprus Trahanas and of Turkish Tarhana: a review of some literature data

Greek and Cyprus Trahanas are the most popular fermented milk-cereal products of Greece and Cyprus, and are produced during summer from fresh ewes’, goats’ milk or a mixture of them. Broken wheat is then added to the fermented milk and heated to cook the mixture and then a thick paste is left to cool and cut into small pieces and left to dry (sun or oven drying). In Greek trahanas, fermentation of the lactic acid bacteria Streptococcus lactis, Streptococcus diacetylactis, Leuconostoc cremoris, Lactobacillus lactis, Lactobacillus casei, Lactobacillus bulgaricus and Lactobacillus acidophilus plays the major acid- and aroma -producing roles. A great biodiversity of microorganisms was observed during Cyprus trahanas fermentation. Lactic acid bacteria (LAB) were the predominant group, followed by yeasts. Lactococcus, Lactobacillus, and yeast species contribute greatly to its fermentation. Turkish Tarhana is the dry form of yoghurt-cereal mixture that is produced by mixing cereal flour, yoghurt, baker’s yeast (Saccharomyces cerevisiae) and cooked vegetables, salt and spices followed by fermentation for one to seven days. The fermented slurry is then air-dried and used in soup making. LAB species found in Tarhana fermentation vary depending on the raw materials, fermentation time and techniques used for its production and play an important role in lactic acid and aromatic compounds formation. Lactococcuslactis spp. lactis, Leuconostoc mesenteroides, Lactobacillus acidophilus, Enterococcus durans, Pediococcus spp., Lactobacillus delbrueckii ssp. lactis and Lactobacillus paracasei bacteria played a role during the fermentation of Tarhana dough. Yeasts were mainly represented by S. cerevisiae.

Feasibility of Mynxgrip®-Assisted Percutaneous Transhepatic Portal Venous Access Closure.

Life-threatening bleeding may occur following percutaneous portal venous access procedures. Various embolic agents have been utilised to minimise this risk, each with their own disadvantages, including inadvertent embolization of the portal vein and inadequate tract embolization. We aim to assess the feasibility of a novel approach to percutaneous portal venous access closure by utilising the MYNXGRIP® vascular closure device (Cardinal Health, USA). This retrospective study analysed 20 patients who underwent interventional radiological procedures with closure of the percutaneous transhepatic portal venous access tract using the MYNXGRIP® closure device with either N-butyl cyanoacrylate or thick gelatin paste. None of these patients demonstrated clinical evidence of post-procedural haemorrhage, which was further confirmed on abdominal imaging in 15 of these patients. MYNXGRIP®-assisted percutaneous transhepatic portal venous access closure is feasible and able to achieve haemostasis with minimal embolization risk.

Finger Metallization Using Pattern Transfer Printing Technology for c-Si Solar Cell

Front metallization of crystalline silicon solar cells requires smaller finger lines in order to collect the generated current from the active area efficiently. Pattern transfer printing (PTP) technology enables finger widths down to 20 μm and aspect ratios above 0.6 using thick film silver paste. This work investigates the influence of PTP process parameters, i.e., laser power and trench geometry, on the finger geometry and the print quality. Silver fingers obtained from four different trench geometries were analyzed and the electrical parameters of corresponding printed solar cells were compared with standard screen-printed solar cells. We observed a strong dependence of the finger aspect ratio and the amount of debris on the laser power that was used during the transfer process. Each trench geometry requires a different laser power, which is related to the ratio between the circumference and the horizontal interface of the trench. Despite a modest FF loss due to higher series resistance, a significant gain in Jsc and a smaller gain in Voc increased the cell efficiency by 0.12%abs for the best group of PTP-printed cells compared with the reference screen-printed cells. Importantly, the amount of silver required was reduced by 54% compared with the screen-printed reference.

Production of sub-micro sized silver particles by chemical reduction method in an environmentally-friendly manner

Silver nitrate in the solution was reduced in the presence of the dispersants by ascorbic acid, and silver particles were generated. The main goal was to examine the influence of different dispersants. The purpose was to improve the production process of the micro-sized silver powder for thick film silver pastes for applications in the photovoltaic sector and the printed electronics. Relatively high concentrations of the reagents were used to achieve a high yield of silver particles. It was a strict request for highly economic production. This paper shows the possibilities for the routes for future large-scale synthesis and potential industrial production. The particles were analyzed by the X-ray diffraction (XRD), scanning electron microscopy (SEM), and laser diffraction particle size analyzer.

Correlation of the sensory attributes of thick yam paste ( amala ) and the functional and pasting properties of the flour as affected by storage periods and packaging materials

Correlation of the sensory attributes of thick yam paste ( <i>amala</i> ) and the functional and pasting properties of the flour as affected by storage periods and packaging materials

Piezoresistive disposable weight sensor with increased sensitivity

This study presents the design, simulation, implementation, and experimental characterization of a paperbased perforated disposable weight sensor system with a double piezoresistive layer. The demonstrated system is designed to achieve highly sensitive weight sensing operations with low-cost materials. For that purpose, the main fabrication material of the proposed disposable sensor is selected as a 289 $\mu$m thick Strathmore 400 series Bristol paper. Approximately 48 $\mu$m thick piezoresistive graphite paste is coated onto both sides of the paper-based cantilever beam with the aim of acquiring more sensitive weight-sensing capability. Additionally, the proposed paper-based structure has rows of closely spaced perforations at prespecified locations to facilitate the bending of the cantilever beam and to further increase the sensitivity of the system. A peripheral electronic read-out circuitry is developed and integrated into the system. It is experimentally demonstrated that the proposed weight-sensing system can measure miniature weights ranging to 2 g with a resolution of 20 mg. The implemented sensor has a sensitivity of 17.13 mV/mN or 168.01 mV/g. Key words: This study presents the design, simulation, implementation, and experimental characterization of a paperbased perforated disposable weight sensor system with a double piezoresistive layer. The demonstrated system is designed to achieve highly sensitive weight sensing operations with low-cost materials. For that purpose, the main fabrication material of the proposed disposable sensor is selected as a 289$\mu$m thick Strathmore 400 series Bristol paper. Approximately 48 $\mu$m thick piezoresistive graphite paste is coated onto both sides of the paper based cantilever beam with the aim of acquiring more sensitive weight-sensing capability. Additionally, the proposed paper-based structure has rows of closely spaced perforations at prespecified locations to facilitate the bending of the cantilever beam and to further increase the sensitivity of the system. A peripheral electronic read-out circuitry is developed and integrated into the system. It is experimentally demonstrated that the proposed weight-sensing system can measure miniature weights ranging to 2 g with a resolution of 20 mg. The implemented sensor has a sensitivity of 17.13 mV/mN or 168.01 mV/g.

Using the clay slip game in art therapy: a sensory intervention

ABSTRACT The goal of the present study was to achieve a better understanding of the experience of playing with slip and the ways in which participants experience the Clay Slip Game and how they perceive the therapeutic qualities of the material, thus including the potential for art therapists to add the Slip Game to their toolbox. Ten experienced qualified art therapists and 48 art therapy students took part. All participants engaged in the Slip Game during the study and reported their experiences in an interview (therapists) or in written personal reflections (students). Data analysis adhered to the principles of Grounded Theory [Charmaz (2006). Constructing grounded theory: A practical guide through qualitative analysis. London: Sage Publications]. The findings indicate that the experience of the Slip Game is mainly a sensory (tactile), playful, pleasant and calming experience of making without the need to produce an end product. The experience is more internal (meditative) and stimulates feelings of regression. The therapeutic qualities of the material, as discussed by the participants, are related to the regressive and sublimative processes afforded by the material, and as a material that enables sensory, behavioural, emotional, and motor regulation. Plain-language summary Art therapy is a type of psychotherapy that uses artistic materials and creative processes in the therapeutic process. Since art materials are the primary tools through which the art therapy processes occur, therapists need to have an in-depth understanding of the art materials they offer to their clients [Moon (2010). Materials & media in art therapy: Critical understandings of diverse artistic vocabularies. New York, NY: Routledge]. Slip is a mixture of water with an additional substance that produces a thick and saline-type paste [De Montmollin (2010). The barbotine game-challenge of creativity. Antwerpen.]. It can be made by diluting and filtering any kind of clay to make it semi-fluid. Playing with slip as a distinct and separate technique was defined as a ‘game’ by Daniel De Montmollin, a ceramicist. De Montmollin created the Slip Game as a way to help people free themselves from internal and external censorship or criticism. The goal of this study was to understand the participants’ experience of the Slip Game and whether they found the process therapeutic. Forty-eight art therapy students and 10 art therapists took part in the study. After engaging in the Slip Game, the art therapists reported their experiences in an interview and the students wrote personal reflections. These were then analysed using Grounded Theory. The findings show that the participants experienced the Slip Game as mainly sensory and reported it was pleasant, calming, playful and tactile, a way of ‘making’ without the need to produce an end product. They also found the experience to be meditative, that it stimulated feelings of regression and felt that engaging with slip also improved behaviour, emotional control and fine hand-movement skills.

Development of thick celery-based paste recipe

This paper is devoted to solving the problem related to increasing the nutritional value of sugar confectionery products, since they are highly consumed among the population. At the same time, they have some disadvantages related to high energy value and lack of vitamins, minerals and food fibres. It is possible to solve this problem by mixing different raw materials. One of the promising raw materials for the food industry is celery, which can become a source of vitamins, minerals and dietary fibres which are needed by human body. The recipe and manufacturing process for cooking thick fruity paste with the use of celery have been developed. Structural and mechanical properties (elasticity, firmness) of thick fruity pastes were studied in order to obtain a product with the desired properties and having the increased nutrition value. Then, regression analysis of the experimental data was performed using Microsoft Office Excel 2007. On the basis of the results thus obtained optimal ratio of ingredients in a thick fruity paste recipe was determined. This food product has high organoleptic, structural-mechanical properties and is a source of food nutrients essential for the body.

Shrinkage and impact strength of fibre-reinforced artificial lightweight aggregate concrete

A sustainable High-Performance Lightweight Aggregate Concrete (HPLWAC) that uses artificial aggregate as part of its coarse ingredients (LWA) as well as being reinforced with single, double, and triple hybrid fibres in many forms, and aspect ratios (l/d) was developed. HPLWAC with a compressive strength of 47MPa and an oven-dry density equal to 1828 kg/m3 at 28 days, was made using various fibres: steel fibres with hooked ends (S1), plastic fibre (P), micro steel fibre (S), and polypropylene fibre (PP). In addition, four mixes of each type of HPLWAC were considered: reference concrete mix, single-fibre reinforced concrete mix, double-hybrid concrete mix, and triple-hybrid concrete mix. Concrete specimens reinforced with the triple hybrid fibre (MAH5) withstood the maximum number of the blows to ultimate failure and first crack. The increments of rate of increase in impact resistance to ultimate failure were 1275, 977, 950, and 862 % at 7, 28, 60, and 90 days compared with the reference concrete. The drying shrinkage related to the concrete sample reinforced with single plastic fibres was reduced in comparison to the reference concrete. The percentage reductions in drying shrinkage of the single fibre (MAP) concrete specimen were 30.54 %, 20.23%, 16.12%, 14.38 %, 14.26 %, and 12.14% at 7, 14, 28, 60, 90, and 180 days respectively. The hybrid fibre-reinforced samples (MAH4 and MAH5) indicated a reduction in drying shrinkage in comparison to the samples reinforced with single plastic fibre (MAP). The percentage decreases in the drying shrinkage for (MAH5) were 58.3%, 40.6 %, 32.7% 26.4%, 252%, and 19.5% at 7, 14, 28, 60, 90, and 180 days, respectively in comparison with the reduced e reference specimen (MAR). SEM indicated that all the specimens of HPLWAC had thick and dense cement pastes with elevated C-S-H content and reduced porosity indicating that high-strength was obtained for such specimens.

Effect of Cassava Flour on the Physico-chemical and Sensory Properties of Konkonde, a Traditional Dish Prepared from Unripe Plantain Flour

Plantain flour is gradually finding applications in weaning food supplementation and composite flour preparations in Cote d’Ivoire. This study therefore aimed at evaluating the effect of cassava flour fortification on physicochemical and sensory properties consumer acceptability of plantain flour. The plantain-cassava mixes were prepared from green plantain and cassava. Substituted plantain flour with cassava flour at varying proportions (100:0; 90:10; 80:20; 70:30; 60:40; 50:50) was evaluated for physicochemical and properties. Reconstituted thick paste konkonde” prepared from all the flour samples were evaluated for consumer acceptability. Substitution of unripe plantain flour with cassava flour up to a level of 20% had no significant (p>0.05) effect on the colour, texture and overall acceptability of the konkonde samples. The swelling power and solubility of the flour samples decreased while the water absorption capacity and bulk density increased on cassava substitution. The pasting viscosity analysis showed that cassava flour addition increased the peak viscosity and breakdown of the flour while the peak time and pasting temperature decreased. The sensory evaluation of the reconstituted plantain thick paste indicated a sharp difference at 5 % probability level in all quality attributes between 30 to 40% substitution, while that 30% cassava flour reconstituted “konkonde” was more preferred.

Highly Porous Polymer-Derived Bioceramics Based on a Complex Hardystonite Solid Solution.

Highly porous bioceramics, based on a complex hardystonite solid solution, were developed from silicone resins and micro-sized oxide fillers fired in air at 950 °C. Besides CaO, SrO, MgO, and ZnO precursors, and the commercial embedded silicone resins, calcium borate was essential in providing the liquid phase upon firing and favouring the formation of an unprecedented hardystonite solid solution, corresponding to the formula (Ca0.70Sr0.30)2(Zn0.72Mg0.15Si0.13) (Si0.85B0.15)2O7. Silicone-filler mixtures could be used in the form of thick pastes for direct ink writing of reticulated scaffolds or for direct foaming. The latter shaping option benefited from the use of hydrated calcium borate, which underwent dehydration, with water vapour release, at a low temperature (420 °C). Both scaffolds and foams confirmed the already-obtained phase assemblage, after firing, and exhibited remarkable strength-to-density ratios. Finally, preliminary cell tests excluded any cytotoxicity that could be derived from the formation of a boro-silicate glassy phase.

A major discovery in Permian volcanic rock gas reservoir exploration in the Sichuan Basin and its implications

Recently, a high-yield gas flow of 22.5 × 104 m3/d was achieved in the wildcat well Yongtan 1, deployed by PetroChina Southwest Oil and Gasfield Company, and an extrusive facies volcaniclastic gas reservoir was first discovered in the Sichuan Basin, which is a major breakthrough in the exploration of volcanic rock gas reservoirs. In order to further evaluate the exploration potential in Permian volcanic rock gas reservoirs in this basin, we systematically reviewed and summarized the exploration process of volcanic rocks in this study area, as well as the characteristics of gas reservoirs of well Yongtan 1, the controlling factors and modes of hydrocarbon accumulation. The following findings were obtained. (1) Over the past five decades of gas exploration of volcanic rocks, the change of exploration thought and progress in seismic prediction contribute to a major discovery in this study area, i.e., the well location deployment of Yongtan 1 was determined in the Jianyan area, where the volcanic anomalies of the Permian developed outbursts are well developed and the gas reservoir conditions are favorable. This also proves that another new gas exploration area in this basin was found. (2) From the data of Yongtan 1, we found high-quality volcanic porous reservoirs with a thickness of over 100 m developed in the Permian strata, the effusive volcanic rock types dominated by breccia and tuffaceous breccia, reservoir space composed of dissolution pores, interbreccia dissolution pores, and other pores, the porosity of which is 6.68%–13.22% and 10.26% on average, the permeability 0.01–4.43 mD and 2.35 mD on average. (3) This abnormally high pressure gas reservoir was buried 4500–6000 m deep underground with the middle formation pressure being 125.625 MPa and the pressure coefficient being up to 2.22. Methane content in the minor H2S-bearing produced gas flow reached up to 99.03%. (4) Volcanic rocks in the Jianyang–Zhongjiang–Santai area are developed, and they are adjacent to the Cambrian high-quality source rocks in the Deyang–Anyue rifting. The early extensional deep faults play a role in connecting source and storage. There are many sets of caprocks, such as the Upper Permian Longtan Formation and Lower Triassic layered thick paste rocks, providing conditions for forming large-scale tectonic–lithologic composite trap gas reservoirs, and the favorable exploration area reaches up to 6000 km2. In conclusion, this major discovery not only proves that Permian volcanic rocks in the Sichuan Basin has large potential for oil and gas exploration, but reaffirms the confidence in changing our exploration thought, speeding up new exploration zones and areas, and discovering more and bigger gas fields.