Fragile Structure Research Articles

Effect of triethanolamine on cement paste exposed to external sulfate attack

Triethanolamine (TEA) is a multifunctional organic additive, applied chiefly to a grinding aid and accelerator for cement. Its effect on cement paste in a sulfate-rich environment remains still unclear and elusive. In this paper, the expansion and mechanical performance of cement paste under external sulfate attack were measured. Thermodynamic model lent itself to estimate the correlation between triethanolamine and generated products content ahead of quantified phase analysis. The transformation of internal component was surveyed by multiple technologies of thermal gravimetric (TG), scanning electron microscope (SEM), X-ray diffraction (XRD), and nuclear magnetic resonance (NMR), while inductively coupled plasma (ICP) was applied to investigate the evolution of interstitial ion concentration. Furthermore, the changes of pore structure over immersion time were separately figured and tabulated by virtue of mercury intrusion porosimetry (MIP). The above analysis shows that when cement paste suffers sulfate attack, triethanolamine intensifies the formation of calcite and exacerbates the decalcification of C-S-H, promoting a large quantity of insoluble precipitation including mirabilite of abundant crystalline water which accounts essentially for severe damage. Determined after comprehensive evaluation, the addition of TEA is conducive to the emergence of physical sulfate attack and an increment of the total porosity and permeability, contributing to an extension of microcracks and a more fragile structure, ultimately makes cement paste appear as a reduction in strength and stiffness.

SOCIAL ENGAGEMENT IN OLDER PEOPLE LIVING WITH HIV

Abstract More than 50% of people with HIV (PWH) are at least 50 years old. PWH experience a high prevalence of multiple chronic conditions and fragile social structures. Although social engagement may be protective against detrimental physical, cognitive, and mental health outcomes, there is limited evidence on older PWH’s social engagement and associated factors in engaging with family, friends, and community. This study sought to examine social engagement in a population of older PWH, using the 13-item Frequency of Leisure Activities Scale from the Research on Older Adults with HIV (ROAH 2.0) study at the Weill Cornell Campus in New York City. We conducted factor and regression analyses to characterize social engagement activities and examine their relationships with AIDS diagnosis, social vulnerability index (SVI), financial strain, loneliness, HIV-related stigma, and depressive symptoms, controlling for demographic factors. PWH (n=349, age range=50-84) were less engaged in social (Mean=1.31; SD=0.71) and cultural-physical (e.g. attending cultural events) (Mean=1.55; SD=0.78) than media-based activities (Mean=3.09; SD=0.72), with Omega reliability estimated at 0.716, 0.651, and 0.620 respectively. Having AIDS, experiencing increased HIV-related stigma, loneliness, and depressive symptoms were associated with low social activity engagement (F(6, 316) = 9.87, p < .001). High SVI score and financial strain were negatively associated with engagement in cultural-physical activities (F(5, 317) = 2.61, p < .001). Increased depressive symptoms were negatively associated with engagement in media-based activities (F(4, 318) = 5.88, p < .001). The findings provide foundations for future research to improve our understanding of social engagement in older PWH.

Regenerating Saffron (Crocus sativus L.) from Corm Lateral Buds via Indirect Somatic Embryogenesis.

Saffron (Crocus sativus L.), being one of the distinguished commercial spice crops in the world, is in demand for its culinary, colorant, and pharmaceutical benefits. In this study, a novel indirect somatic embryogenesis (SE) system was, thus, established for the study of this plant. To this end, firstly, the lateral buds were cultured. Then, the cultures were transformed using Murashige and Skoog (MS) medium supplemented with either 6-benzyladenine (BA: 5 and 10 mg/L), naphthalene acetic acid (NAA: 0, 1, and 2 mg/L), or trans-zeatin (tZ: 0, 0.5, and 1.0 mg/L), before being classified into four structures: white globular (WG), yellow compact nodular (YCN), yellow-brown fragile (YBF), and dark-brown porous (DBP). As soon as BA (10 mg/L) and NAA (2 mg/L) were added, elevated percentages of white globular calli (56.8%) and white globular calli (31.5%) structures were induced. Additionally, 6-benzyladenine (5 mg/L) and naphthalene acetic acid (1 mg/L) allowed the formation of yellow-brown fragile structures, and the combination of 6-benzyladenine (10 mg/L) with trans-zeatin (1 mg/L) formed the DBP structures. After three months, the white globular calli were incubated using the MS basal medium, before being augmented with thidiazuron (TDZ: 1 mg/L) and picloram (PIC: 2 mg/L), from which 60% of the cases matured into shoots and, ultimately, cormlets. Morphoanatomical analyses also showed that the white globular calli cells were closely arranged, as they had a dense cytoplasm, a significant vascular differentiation, and embryoids. Furthermore, the yellow compact nodular structures were characterized by a strong differentiation capacity and contained many meristematic cells with high caryomitosis centers. We observed that the yellow-brown fragile calli had looser cell arrangements, with a vascular structure located on the protoderm edge, while there was no obvious cellular arrangement in the dark-brown porous structures. The induction of the adventitious buds in vivo on the MS medium that was supplemented with thidiazuron and picloram accordingly demonstrated the highest rates (60%) of white globular calli.

One-pot coatable fluorinated polyurethane resin solution for robust superhydrophobic anti-fouling surface

Superhydrophobic coating materials have considerable potential in a wide range of industrial applications because of their anti-fouling properties. However, their application is limited due to the instability caused by their fragile structure, resulting in superhydrophobic failure. Moreover, achieving superhydrophobic materials requires complex processes and specialized equipment. Polyurethane (PU) is a promising as a material for superhydrophobic coatings because of its inherent advantages such as adhesion properties and mechanical toughness. In this study, a fluorinated polyurethane (FPU) solution was synthesized using a one-pot method. Further, two types of particles with varying solvent miscibility were blended into an FPU solution. The alterations in surface morphologies, resulting from variations in evaporation conditions due to the different particle compositions, were confirmed through scanning electron microscopy (SEM), which leads to a difference in hydrophobicity. The prepared coating material was shown to tiny thorn-like surface morphology, which allowed it to demonstrate a high water contact angle of 157°, along with additional anti-fouling properties. Furthermore, the resulting superhydrophobic coating materials demonstrate mechanical robustness under cyclic tape peel test even after 10 cycles and cross-cut test Our study offers an effective approach for achieving superhydrophobic properties while maintaining mechanical durability, thereby advancing the development of high-performance superhydrophobic materials.

Enhancing resilience of agricultural microgrid through electricity–heat–water based multi-energy hub considering irradiation intensity uncertainty

Agricultural microgrid propounds a tailored and cost-effective platform for multi-energy supply in rural areas but also faces the challenge of supply outages because of the fragile grid structure. This paper proposes an electricity–heat–water based multi-energy hub (EHWbMEH) to enhance the resilience of agricultural microgrid, with the objectives of minimization of operation cost and maximization of resilience. To this end, the stochastic characteristics and coupling relationship of photovoltaic and solar thermal outputs are first investigated by introducing expected power not served and expected power curtailment. Subsequently, the EHWbMEH consisting of energy conversion, storage, and distribution devices is developed to ensure the resilience of the agricultural microgrid during supply outages. On this basis, a multi-objective resilience-economic operation model for EHWbMEH considering irradiation intensity uncertainty is presented, and the Pareto frontier is derived by applying the multiple preys based evolutionary predator and prey strategy. According to the simulation results, when the electricity, heat, and water supply are interrupted, the total operation cost of the optimal trade-off solution is $3740.141, while the electricity, heat, and water load resilience can reach 63.37%, 84.72%, and 80.55%, respectively. Case studies demonstrate the effectiveness and performance of the proposed method.

Simultaneous anodic de-lithiation/cathodic lithium-embedded regeneration method for recycling of spent LiFePO4 battery

The widespread use of lithium-ion batteries for energy storage will result in millions of tons of scrapped LiFePO4 (LFP) batteries. Current recycling technologies for LFP cathode materials require harsh acid treatments and are expensive. Hence, in this work, an ingenious electrochemical method is developed to recycle scrapped LFP. Specifically, through the charging/discharging process of an electrolytic system in which both the cathode and anode are scrapped LFP, the anode is de-lithiated to obtain FePO4 (FP), meanwhile, the Li+ from the anode is embedded into the cathode scrapped LFP to achieve regeneration. The experimental results show that the anode de-lithiation rate is 92 % and the cathode regeneration performance is closely related to the driving voltage. A voltage of 1 V converts the FP phase to LFP and effectively eliminates the LFP defect lattice. However, an excessive voltage (1.2 V) leads to an extremely fragile LFP crystal structure, resulting in the ineffective embedment of Li+ into the defective lattice and ineffective capacity restoration. The regenerated LFP exhibits a high restored capacity (136.5 mAh g−1 at 1 C) and excellent stability (95.32 % capacity retention after 300 cycles at 5 C). This novel method does not require an additional Li source, consumes low electrical energy (31.9 kWh t−1) and has a high current efficiency (>98 %), and it yields economic and environmental benefits that will contribute to the sustainable development of the LFP industry.

Boosted Charge-Transfer behavior for ultrafast Zn storage by constructing intrinsic heterojunction of ammonium vanadate nanoribbons coupling with interlaminar MXenes nanosheets

Ammonium vanadate (NH4V4O10, NHVO) is one of the most promising cathode materials for aqueous zinc-ion batteries (ZIBs) owing to its inherent large interplanar spacing, highly reversible electrochemical reaction mechanism and admirable specific capacity. However, the fragile interlayer structure and sluggish electron transport behavior generally cause tardy electrochemical reaction kinetics and result in poor cycling stability and rate capabilities. In this work, a novel intrinsic heterojunction cathode (NHVO@MX) of NHVO nanoribbons coupling with inserted Mxenes (MX) nanosheets is rationally constructed on a flexible carbon cloth substrate for wearable ZIB applications. The intercalated MX nanosheets not only serve as the spacer to isolate the NHVO interlayers as well as efficiently accelerate electron and ion transport behaviors, hence preserving the numerous exposed active areas required for rich and rapid Zn storage. Most impressively, it presents the lowest charge-transfer barrier among all the reported vanadate-based materials induced by the interlaminar MX nanosheets, demonstrated by both experimental measurement and theoretical calculation. As a result, the as-prepared heterojunction cathode delivers high specific capacity of 437 mAh·g−1, excellent rate capability and ultralong cycling life (over 2000 cycles). Therefore, manufacturing the heterojunction laminar cathode with incorporated MX can be considered a prospective strategy for next-generation advanced ZIBs.

Young Palestinians’ struggles for accountability and participation: beyond formal systems and public resistance

Young people worldwide are engaged in diverse forms of participation which offer a pathway for demanding accountability from governance actors. In contexts with fragile governance structures, young people face a unique set of challenges in their efforts to demand accountability or participate in decision-making. The expected relationship between participation and accountability as understood in liberal, democratic settings is often absent and instead demands for accountability are often made through strategies ‘at the margins’. Using Palestine as a case study, we show how young people look for accountability beyond state institutions and the national scale, using diverse strategies depending on their embedded position in society. This analysis sheds light on the complex reality of youth participation and accountability mechanisms in socially, politically and physically contested spaces and, by extension, points towards challenges and opportunities in implementing the Sustainable Development Goals.

Technological challenges in production of goat milk products and strategies to overcome them: a review

SummaryIn comparison to bovine milk, compositional differences in goat milk such as lower αs1‐casein and higher β‐casein content, small‐sized fat globules, higher mineral content and medium‐chain fatty acids generate difficulties in manufacturing goat milk products. Majorly, soft and fragile gel structure, lower yield, salty taste and goaty flavour result in decreased acceptability of goat milk products. Therefore, the present review discusses the technological challenges in preparation of goat milk‐based products, mainly yogurt and cheeses. Understanding the challenges involved in preparing goat milk products and overcoming them by modifying the processing parameters and product formulations could help to improve the quality of goat milk products. Thermal treatment, admixture with bovine milk, enzymatic modifications, and membrane processing have shown promising results in improving the final quality of goat milk products. This review strengthens the existing knowledge for producing goat milk products with improved textural and sensorial attributes.

In-plane shear behaviour of concrete sandwich panels reinforced with various geogrids

Seismic occurrences have caused severe damage and even the collapse of fragile unreinforced masonry structures. New technologies are replacing these conventional methods of construction; concrete sandwich panels (CSP) are one such technique gaining popularity. In-plane diagonal shear strength of concrete sandwich panels is studied experimentally, and the effect of incorporating geogrids on the deformation capability and load-bearing capacity is reported. Two forms of geogrid material, plastic uniaxial geogrid (PUG) and polyester biaxial geogrids (PBG2 and PBG3) are used to improve the strength and ductility of concrete sandwich panels. Diagonal compression tests have been carried out better to understand the behavior of CSP under in-plane strength. This paper also discusses the effect of the different mixes, the effect of geogrids, load-deformation behaviour, shear capacity, deflection ductility factor, mode of failure, shear strength, and energy dissipation. In contrast to the control specimen, specimens cast with plastic geogrid had a 13.7% and 26% improvement in shear capacity and load-bearing capability for the two types of micro-concrete mixes used in this study. The conclusion reached is that plastic uniaxial geogrid is effective in improving the concrete sandwich panels’ load-bearing capacity, shear capacity, and deformation ability. Polyester biaxial geogrids enhanced the ductility of the concrete sandwich panels.

Advancements in 3D spheroid imaging: Optimised cryosectioning and immunostaining techniques

This article presents a modified protocol for embedding and sectioning spheroids and organoids, which are increasingly used in research due to their ability to emulate living tissue. The modifications aim to reduce the distortion and damage of these fragile structures during the embedding and sectioning process. The new method involves using optimized embedding containers, a modified embedding protocol, and optimized temperatures for cryosectioning. A heat-induced antigen retrieval protocol was tested and found to significantly increase immunostaining intensity without compromising spheroid integrity. The combined approach allowed for the creation of thinner cryosections, leading to clearer and more detailed images. The results suggest that the modified protocol could be widely adopted to enhance the imaging of spheroids and organoids.•Paraformaldehyde fixation of spheroids•Antigen retrieval treatment of spheroids•Embedding in freezing medium and cryosectioning

The Effect of Uncertainty Intolerance on Career Anxiety and Career Change Intention: A Case Study of the Hospitality Industry

Purpose –A sudden development can quickly have an impact on the tourism sector because of its fragile structure. There are likely to be employment concerns in such an industry. In this study, it is aimed to determine the effect of intolerance of uncertainty on career anxiety and career change intention, as well as the direction and strength of this effect in accommodation business employees.Design/Methodology/Approach –The questionnaire technique, one of the quantitative research methodologies, was used in the research. The questionnaire form was administered to 402 Antalya-based employees of accommodation businesses. On the obtained data, confirmatorys factor analysis, correlation analysis, and path analysis were performed.Results –As a result of the statistical data obtained, the relations between the variables were determined, and all four research hypotheses developed in order to test the research model created based on these relations were accepted. According to the results, prospective anxiety (PA), which is a sub-dimension of intolerance of uncertainty (IU), positively affects career anxiety, as does inhibitory anxiety (IA), which is also a sub-dimension of intolerance of uncertainty. In addition, the sub-dimensions (PA) and (IA) of intolerance touncertainty negatively affect career change intention.Discussion –It can be said that employees' intolerance to uncertainty, career anxiety, and career change intentions are generally at a moderate level. It has been revealed that employees with a high level of intolerance to uncertainty do not turn to career changes dueto their fear of uncertainty as well as their increased career anxiety. This result may indicate the existence of unhappy employees in the sector.

Distribution of ecosystem service potential in marginal agroecosystems in a mosaic-type landscape under exploratory scenarios

ABSTRACT Land-use change in agriculturally marginal mosaic-type landscapes involves economic, environmental, and social aspects and can lead to social and economic problems in rural areas. This study focuses on the western part of Vidzeme Uplands, Latvia, which has been heavily impacted by rural depopulation and agricultural land abandonment. The research explores the value of low-intensity agroecosystems in agriculturally marginal landscapes using an ecosystem service approach. Three scenarios were developed: a ‘business as usual’ scenario, a ‘no subsidies’ scenario, and a ‘payments for ecosystem services’ scenario. The ‘business as usual’ scenario shows a pattern of subtle intensification, while the ‘no subsidies’ scenario predicts a significant loss of low-intensity agroecosystems and their services. The ‘payments for ecosystem services’ scenario estimates the safeguarding of essential regulatory ecosystem services, ensuring the potential supply of provisioning services, and maintaining the fragile structure of the marginal mosaic-type landscape.

Heidegger’s Worldview – Freedom, Control and Affectivity

The tendency of individuals to protect their own worldview by rejecting information and phenomena that cannot be reconciled with it is a significant issue in today’s polarised society. This paper aims to gain a deeper insight into this tendency towards exclusion and the impact it has on worldview by examining a particular interpretation of worldview developed in the late 1930s by Martin Heidegger. It is a radical account that portrays a highly restrictive and extremely closed-off model of worldview, within which exclusion plays a key role. The impact of this exclusion on the nature and shape of worldview is explored by analysing worldview from three distinct perspectives focusing on (1) its appearance, marked by freedom and safety, (2) its inner dynamic, marked by absolute control, and (3) its affective background, marked by frantic struggle and dread. The analysis reveals a dread-fuelled, highly reactionary, and thus extremely fragile structure that is fundamentally shaped by the endless effort to conceal the exclusion on which it is built, resulting in a complete inability to engage with that which is excluded without severely endangering the very existence of that worldview.

Towards Safer All-Solid-State Lithium Metal Batteries by an Artificial Protection Layers

Lithium ion batteries (LIB) are representing a milestone in electrochemical energy storage and are still the state-of-the-art battery system for various mobile and stationary energy storage applications. However, the practical energy density of LIBs starts to reach an asymptotic limit. Beside LIBs, an auspicious variety of battery systems comprising a better option for specific applications in terms of e.g. energy density, so establishing a diversity of specific battery systems for specific applications is a good strategy.[1 ] After initially paving the way for the LIB, the lithium metal battery (LMB) experiences a revival due to an outstanding theoretical specific capacity (3 860 mAh g−1) and low electrochemical potential (−3.04 V vs. SHE). However, continuous electrolyte consumption, the formation of an inhomogeneous SEI and high surface area lithium (HSAL), whose growth is induced by the heterogeneous and fragile structure of the SEI film, are still dominant challenges that need to be overcome. The liquid electrolytes also deal with safety issues like risk of leakage and flammability. The combination of Li metal with solid polymer electrolytes (SPE) could supress HSAL formation and avoid those safety hazards. However, SPEs deal with poor ionic conductivity at room temperature (10−8 S cm−1 ≤ σ ≤ 10−5 S cm−1) and, additionally, it is necessary to control the Li morphology during electrodeposition/dissolution to realize high-energy all-solid-state batteries (ASSB) based on Li metal anodes.[2 ,3 ] Several artificial protective coatings have been proposed to improve the LMA/SPE interface by facilitating the Li ion flux, promoting a homogeneous Li electrodeposition/dissolution and protecting the LMA against electrolyte degradation as well as enhancing the Li wetting interface. The SPE induces a more flexible interphase that withstands the volume change. Recently, metal oxides coated by atomic layer deposition (ALD) have gained attention due to a great thickness control, the possibility of monolayer deposition as well as a consequential homogeneity of the deposited protection layer. Furthermore, ALD is suitable for roll-to-roll coatings which is feasible for industrial application.[3,4 ] Herein, the setup of Li-metal-polymer batteries (LMP® technology) commercialized by Blue Solutions and applied in their “blue cars” (30 kWh, 100 Wh kg-1) was modified in several points. Li metal was coated with a metal oxide via atomic layer deposition (ALD) to form an intermetallic phase as protective layer and to improve the Li+ flux. The artificial protective coating at Li metal was combined with a PEO- and/or polyether-based SPE and the effect of the modifications on the electrochemical performance in different ASSB setups was investigated and characterized.[1] Placke, T.; Kloepsch, R.; Dühnen, S.; Winter, M. Lithium ion, lithium metal, and alternative rechargeable battery technologies: the odyssey for high energy density. Journal of Solid State Electrochemistry 2017, 21, 1939-1964.[2] Cheng, X.-B.; Zhang, R.; Zhao, C.-Z.; Zhang, Q. Toward Safe Lithium Metal Anode in Rechargeable Batteries: A Review. Chemical Reviews 2017, 117, 10403-10473.[3] Han, Z.; Zhang, C.; Lin, Q.; Zhang, Y.; Deng, Y.; Han, J.; Wu, D.; Kang, F.; Yang, Q. H.; Lv, W. A Protective Layer for Lithium Metal Anode: Why and How. Small Methods 2021, 5, 2001035.[4] Han, Y.; Liu, B.; Xiao, Z.; Zhang, W.; Wang, X.; Pan, G.; Xia, Y.; Xia, X.; Tu, J. Interface issues of lithium metal anode for high‐energy batteries: Challenges, strategies, and perspectives. InfoMat 2021, 3, 155-174.

Unraveling the deterioration mechanism of dough during whole wheat flour processing: A case study of gluten protein containing arabinoxylan with different molecular weights

This study aims to the effect of arabinoxylan (AX) on gluten quality. Ultrasonic treatment is utilized to degrade water unextractable arabinoxylans (WUAX) from wheat bran, which obtains three molecular weights of AX. The results indicate that the shear viscosity and particle size of AX were decreased and the ζ-potential was increased after ultrasonic treatment. Analysis of the gluten shows that the free SH of gluten with 6% WUAX, SAX10, and SAX30 (ultrasound duration for 10 min and 30 min) was increased by 51.9%, 48.1%, and 17.0%, respectively, whereas the free SH of 2% SAX30-gluten was increased by 19.8%. Furthermore, WUAX impaired the viscoelasticity properties of gluten, while SAX30 improved the viscoelasticity of gluten. WUAX induced the open, fragile, and discontinuous structure of gluten. On the contrary, SAX30 promoted the formation of the compact and regular gluten structure. Overall, ultrasonic as a non-chemical treatment could be used to improve the quality of whole-wheat foods.

Evaluation and Optimization of Particle Removal with a Resist Peeling Method

The removal of particle contamination is key to maximize yield. Some common particle removal techniques are not relevant anymore when complex and fragile structures are present on the surface. This led to the development of new cleaning processes based on innovative concepts to improve particle removal efficiency without any pattern damage. Some of these processes rely on a resist film lift off. One of these particle removal processes is studied in this paper. The process consists in some resist spin-coating followed by a diluted ammonia dispense to remove this film, which results in particle removal. This specific resist film is made of two immiscible organic polymers. A study was conducted to understand how the organization of these two polymers in the film is key for the film lift-off and the cleaning efficiency. This organization was shown to depend on the substrate contact angle and the resist formulation. A surface preparation is required on hydrophobic surface to reduce their water contact angle and ensure the efficiency of the process. As a result, compared to a high velocity aerosol cleaning technique, this resist peeling process requires multiple steps and a significant process time. A Particle Removal Efficiency study was then performed on blanket wafers to determine and understand how the different process parameters impacted on the cleaning efficiency. It led to the optimization of this process efficiency on blanket wafers. A comparison between an optimized process and a high velocity aerosol cleaning technique underlined the potential of such a process. Compared to high velocity aerosol cleaning, it demonstrated higher efficiency on blanket wafers, without causing any pattern damage on patterned wafers. These results lead to promising perspectives for using this process in the cleaning of fragile structure or targeting small particles with high adhesion.

LARGE-AREA FABRICATION OF A HARD AND WEAR-RESISTANT SUPERHYDROPHOBIC MATERIAl

Different types of superhydrophobic materials have been fabricated by constructing surfaces with low surface energy and micro-nanostructures, most of which are coatings. Due to the fragile rough structure of the coating, it is very easy to lose its superhydrophobic properties when exposed to friction, corrosion, high temperature, and other effects of the external environment. This has largely hindered the large-scale application of superhydrophobic materials. Here, a rigid superhydrophobic material with polyurethane foam as the substrate, polytetrafluoroethylene (PTFE) nanoparticles as the matrix phase, and carbon nanotubes as the reinforcing phase have been reported. The fabricated material showed excellent superhydrophobicity (157∘ ± 1∘) and robustness. The contact angle of the superhydrophobic material surface remained above 150∘ and the rolling angle below 10∘ after 1000 cycles (distance is 40[Formula: see text]m) of abrasion using 800 # sandpaper at pressure of 5[Formula: see text]kPa.

Soil Structure in Volcanic Pumice Soil of Dozou-sawa River Evaluated from In Situ and Laboratory Tests

Abstract Volcanic pumice soils are widely distributed in many countries and sometimes cause severe geo-disasters including large-scale slope failures and long-distance debris flows triggered by seismic ground motion. However, the understanding of the mechanical properties of volcanic pumice soils is still limited because volcanic pumice soils generally have a sensitive structure and are typically distributed in mountain areas that are sometimes difficult to approach. In this study, a portable in situ direct shear test apparatus was developed to evaluate shear strengths of a volcanic pumice soil without disturbing the natural soil structure. A series of in situ direct shear tests was conducted for the volcanic pumice soil in Dozou-sawa river, where a large-scale slope failure followed by debris flow occurred in the 2008 Iwate-Miyagi Nairiku Earthquake. A series of laboratory direct shear tests and triaxial tests were also carried out with intact and reconstituted specimens. The in situ direct shear tests and laboratory direct shear tests using intact specimens showed consistent shear strength. Intact specimens had an extremely loose and sensitive structure because of highly crushable porous particles and a very loose soil skeleton sustained by weak cementation between particles. Such a fragile soil structure could never be reproduced in reconstituted specimens. It was confirmed that the soil structure significantly affected peak shear strengths. For the evaluation of mechanical behavior of such sensitive soils, it is important to use as few disturbed specimens as possible. The newly developed in situ direct shear test apparatus was confirmed to be an effective tool to simply evaluate the shear strength of sensitive volcanic pumice soils on site under low disturbed conditions.

The quality of whipped cream: Effect of polyglycerol ester on the crystallization of fat blend and the properties of interface

This study investigated the effect of polyglycerol ester (PGE) on the crystallization of fat blend and the properties of interface, as well as their influence on the quality of whipped cream. PGE, as a nucleation inducer, facilitated the nucleation of fat blend, thereby forming small and uniform crystals. When PGE concentration was lower than 0.10 wt%, PGE coexisted with sodium caseinate (SC) at oil-water interface, decreasing the interfacial tension as well as increasing the interfacial elasticity modulus (E′) and the interfacial protein concentration (ζ), therefore improving the stability of emulsions. Moreover, PGE could increase the extent of partial coalescence and the ζ in whipped creams, leading to the formation of firmly foam structures, which in turn increased the firmness and decreased the serum loss. When PGE concentration was higher than 0.10 wt%, PGE displaced SC, decreasing the E′ and the ζ, thereby some large and irregular fat globules were observed in emulsions which caused the instability of emulsions. Besides, low degree of partial coalescence and ζ resulted in the formation of loose and fragile foam structures, thereby decreasing the firmness and increasing the serum loss of whipped creams. Overall, this study could provide theoretical guidance on how to accurately control and modify the quality of whipped creams.