Amount Of Resin Research Articles

LOAD TRANSFER RESTORATION AT JOINTS

The development of a cost-effective method for restoring load transfer at concrete pavement joints has significant implications for maintaining the longevity and usability of roadways. Recognizing early signs of damage in concrete pavements, a French team proposed an innovative solution to restore load transfer by using a method that involves minimal machinery and low amounts of resin for anchoring. This method notably differs from existing techniques by its efficiency, reduced costs, and ability to handle high traffic levels without significant road closures. Initial in-situ tests demonstrated the method's effectiveness in reducing deflections and ensuring the perfect transmission of loads across joints, suggesting its short-term viability. The method, characterized by drilling holes across the joint and inserting a specially designed connector, addresses the challenges of early joint deterioration without extensive machining or the use of large quantities of resin. Further developments led to the design of a complex key that combined metallic and spring elements to ensure constant compression and adaptability to thermal conditions. However, this approach was eventually simplified to a connector system that achieved the desired load transfer restoration with even greater efficiency. Practical applications of this method on French roadways and the development of specialized machinery for rapid installation highlight its potential to significantly extend the service life of concrete pavements at a lower cost compared to traditional maintenance strategies. This method's adoption could transform concrete pavement maintenance, offering a sustainable solution to common deterioration challenges faced worldwide. (Abstract generated by AI tool ChatGPT 4)

Plant Resin Delivery by Nanovectors as an Emerging Approach to Boost Solubility, Permeability and Bioavailability.

Resins are complex mixtures of natural constituents containing non-volatile and volatile terpenes, in combination with gums and polyphenols, used since ancient times for their medicinal properties. Current research has evidenced their therapeutic value with a plethora of activities. The main limits of resins and their constituents for their clinical use are low water solubility, poor stability and bioavailability. Therefore, nanovectors including vesicles, solid lipid nanoparticles, micelles, nanoemulsions, microemulsions and mesoporic nanoparticles have been investigated to optimize the biopharmaceutical properties after topical or oral administration of resins or fractions from them, including essential oils or single constituents. In this review, we report the results evidencing that developed nanovectors were able to entrap high amounts of resins or their components, modify the release properties, enhance their cellular uptake and penetration across biological barriers and optimize the biopharmaceutical properties. In addition, the resins or their fractions as enhancer penetration molecules can optimize the architecture and properties of nanovectors in their capacity to circumvent biological barriers. Although no clinical studies have been reported until now, nanovectors represent a huge platform for upgrading therapies and emerging new treatments of resins such as wound healing therapy.

SHEAR STRENGTH PARAMETERS AND DEFORMABILITY PROPERTIES OF SILICATE-BASED RESIN ADDED SAND-TYPE SOIL SPECIMENS

In this study, the shear strength, uniaxial compressive strength (UCS) values and deformability properties of silicate-based polymer resin added silty sand type soil specimens were examined through a series of experimental studies. Although the UCS and shear strength values increased, minor decreases in the internal friction angle values were measured as the resin ratio increased. It was determined that the main reason for the improvement in strength values due to the increase in resin content is the increase in cohesion values. It was found that the UCS values calculated according to the cohesion and internal friction angle parameters of the Mohr & Coulomb failure criterion (UCSc) were 2.6-3.0 times lower than the values obtained from the direct UCS experiment. According to this finding, it was concluded that the Mohr & Coulomb failure criterion is not properly usable to represent the mechanical behaviors of resin added sands. As another outcome, the ratio between UCS/UCSc slightly decreased with an increase in the resin amount. In other words, it has been determined that the Mohr&Coulomb failure criterion gives a bit more inaccurate results for the specimens with low binder contents. With the increase in the resin content ratio, significant increases were obtained in both elastic modulus and ductility properties of the samples. It has been evaluated that the silicate-based polymer resin binder is advantageous to provide significant increases in the toughness and energy absorption capacity of soils.

Technogenic hazards coefficient of sand-resin mixtures in foundry manufacturing

Purpose. To carry out a comparative quantitative assessment of environmental and sanitary-hygienic hazards of utilizing synthetic resins for manufacturing molds and rods in foundry production. Methodology. Quarry quartz sand brand 1K2O202, furan resin brand Permaset 839 and catalyst Permacat 128, aluminum alloy AL2, gray cast iron SCh200, carbon steel 30L, bronze BrА9Zh3L were used in the work. Chromel-alumel thermocouples completed with electronic potentiometer were used for thermography. Molds were made from quartz sand, furan resin and catalyst mixture. Casting mold heating depth determination from casting to temperatures above 400 °C was carried out by its thermogram graphical processing, which was obtained after casting mold pouring with aluminum alloy, bronze, gray cast iron and carbon steel. Findings. Among those studied, the most dangerous are urea-phenol-formaldehyde, urea-formaldehyde and urea-furan resins, and the least dangerous are phenol-formaldehyde and phenol-formaldehyde-furan resins. Ecological and sanitary-hygienic hazard level when using resin mixtures increases with increasing resin amount in mixture, castings walls thickness, their surface area, as well as with increasing temperature of melt poured into the mold. Originality. For the first time, in relation to foundry molds and rods in foundry production manufacturing, technogenic hazard coefficient (THC) has been developed and its value has been calculated. This, in fact, is air volume (m3) containing maximum permissible concentration of carcinogenic or poisonous substances released as a result of mold organic binder material destruction when pouring aluminum alloy, bronze, cast iron or steel. Practical value. The use of the research results makes it possible to increase the level of predicting accuracy of technogenic (sanitary, hygienic and environmental) hazards, accuracy level of calculating ventilation systems capacities in foundries, taking into account the serial castings production, castings structural features, as well as binding materials nature for foundry molds and rods for such castings.

INVESTIGATION OF EXPANDED CLAY AGGREGATE AND PINE RESIN ADDED PLASTER WITH CEMENT IN BIOMEDICAL MATERIAL STORAGE INSULATION

In this study, the aim was to produce cement-plaster with expanded clay aggregate and pine resin as additives to enhance the strength for the preservation of medical and biomedical materials in storage facilities, without being affected by heat and humidity, instead of traditional aggregates. In the prepared samples for the experimental study, expanded clay aggregate with particle sizes of 0-2 mm and 2-4 mm was mixed with cement binder in weight percentages of 20%, 40%, 60%, and 80%. Additionally, resin was added to the mixtures in weight percentages of 0%, 0.5%, 1%, and 2%. A total of 32 samples were produced. In the study, resin-enhanced CEM IV/B 32.5 R type pozzolanic cement were used. As the amount of resin added to the samples increased, the thermal conductivity and compressive strength decreased. The lowest thermal conductivity was observed in samples with 2-4 mm particle size, 80% expanded clay aggregate, and 2% resin content in cement-based samples at 0.152 W/mK. The highest compressive strength was observed in cement-based samples, with 22.5 MPa for the resin-free sample containing 0-2 mm particle size and 20% expanded clay aggregate. The water absorption rate of the samples remained below the critical value of 30% in cement-based samples.

Influence of fly ash and waste tire rubber particles on mechanical and tribological properties of composite brake linings

AbstractTo investigate the influence of waste tire rubber (WTR) and fly ash (FA) on mechanical and tribological properties of composite brake linings, 8 different formulations of 8–40 wt% FA and 10–12 wt% WTR were selected. The mechanical tests showed that high amounts of resin and FA result in the highest hardness. The inclusion of WTR, decreased hardness and internal shear strength; however, increased the acetone extraction and resistance to coefficient of friction (COF) fluctuations. With the use of WTR, steady COF fluctuations with the temperature changes are achieved. The tribological properties were evaluated with both a drum‐type and disc‐type dynamometer by the SAE‐J661 standard. Reduced COF fluctuations were observed in <15 wt% FA and 10 wt% WTR containing samples. The highest COF was obtained for the 14 wt% FA and the lowest wear rate for the samples containing 8 wt% FA. The brake composites exhibited consistent COF in the range of 0.34–0.52, and wear rates lower than 7 wt%. Two compositions containing 40 and 25 wt% FA (no WTR), and one containing 10 wt% WTR and 8 wt% FA provided the best results. Finally, four best compositions were selected and worn surfaces were analyzed with SEM after full‐scale dynamometer tests.Highlights Three composites with high waste percentage were successfully manufactured Fly ash and waste rubber are used without any post‐processing to cut costs Waste rubber increased resistance to COF fluctuations with temperature change Full‐scale dynamometer tests are performed for friction and wear properties Worn surfaces were analyzed with SEM method

Assessment of fiber loading effects on mechanical properties and prediction of mechanical properties via artificial neural networks of hybrid jute /sheep wool epoxy composites

Abstract The primary purpose of this study is to realize the effect of fibre loading on mechanical properties like tensile, bending, impact, interlaminar shear strength and fracture toughness of hybrid composites made of alkaline treated jute and sheep wool hybrid fibres and epoxy. A series of composite laminates were prepared with varying fibre (30%, 40%, 50% and 60%) loadings using hand layup technique. The findings indicated that hybrid composite with equal amount of fiber and resin (JW50) showed a higher strength of 40 MPa against tensile load, maximum strength of 99 MPa against bending load, superior interlaminar shear strength (ILSS) of 3.09 MPa, and a maximum fracture toughness of 72 MPa.m1/2 compared to other fibre loadings. In terms of impact test, JW50 displayed the highest impact strength of 85.98 J/m, underscoring its exceptional capacity to absorb energy compared to other composites. The mechanical strengths of these composites were also predicted using an Artificial Neural Network (ANN) model, which generated accuracy of 87.46% for tensile strength, 86.31% for flexural strength, and 83.52% for impact strength. The absolute percentage errors were found to be 12.53%, 13.68%, and 16.47%, respectively, demonstrating the model’s reliability in estimating composite properties based on fibre content and composition. SEM images of fractured samples under tensile load reveal that higher resin content reduces fibre-matrix bonding, while a balanced fibre-to-resin ratio improves load transfer, but too much fibre leads to debonding due to inadequate resin justifying the experimental results.

Effects of hot-pressing parameters on the properties of waste Tetra Pak/bamboo composites

Waste Tetra Pak containers, from the same brand of milk, were crushed into fibers. They were formed into composites with 40-mesh bamboo fibers with phenolic resin and hot pressed with different parameters. The effects of hot-pressing temperature, hot-pressing time, hot-pressing pressure, phenolic resin amount, and the ratio of Tetra Pak and bamboo on the elastic modulus, static bending strength, internal adhesive bonding strength, and 24 h thickness swelling rate of the composites were investigated by orthogonal testing. The results showed that during the hot-pressing process, hot-pressing temperature was the most important factor for the elastic modulus and static bending strength of the composites and the hot-pressing pressure was the most important factor for the 24 h thickness swelling of the composites. Optimal hot-pressing parameters of TP/bamboo composites were a hot-pressing temperature of 180 °C, hot-pressing time of 16 min, hot-pressing pressure of 1.0 MPa, phenolic resin amount of 12%, and ratio of Tetra Pak/bamboo of 9:1, in which the least phenolic resin and the most Tetra Pak materials were added. Moreover, the elastic modulus was 7670 MPa, the bending strength was 40 MPa, the internal adhesive bonding strength was 0.86 MPa, and 24 h thickness swelling rate was 10.6%, meeting the requirements for MDF in different states.

Utilization of Waste Melamine Formaldehyde Resin As an Enhancer in g-C3N4 Photocatalyst and Photoelectrochemical Applications

Melamine Formaldehyde resin (MF), one of the thermoset plastic frequently used for cook wares, adhesive, insulator and coatings because of its thermostability, mechanical strength, electronic insulation and ease of manufacture. However, because of above properties of MF resin, it is hard to recycle after used, which causes serious environmental contamination. To overcome this drawback of after-used MF resin, we introduce a method on utilizing after-used MF resin for an enhancer of g-C3N4 photocatalyst, inspired by pristine methodologies to synthesize g-C3N4 photocatalyst.The pristine g-C3N4 photocatalyst is synthesized by heat polymerization of urea, dicyandiamide(DCDA) and melamine and it utilize widely as a photocatalytst because it has a suitable band gap for visible light absorption, high chemical stability, and high thermal stability. However, high electron-hole recombination rate of g-C3N4 photocatalyst regarded as the reason decreases photocatalytic activity of g-C3N4 photocatalyst.Therefore, in this study, after-used MF resin as an enhancer during g-C3N4 photocatalyst syntehsis process, to improve photocatalytic activity of g-C3N4. The pure g-C3N4 photocatalyst was synthesized by heat polyemrization of urea and MF resin added g-C3N4 photocatalyst (MR X, X is the amount of added MF resin) was synthesized by adding certain amount of MF resin during g-C3N4 synthesis process. Comparing photocatalytic activity between pure g-C3N4 and MR photocatalyst was carried out by Methyl Orange (MO) degradation under 1 sun illumination. Finally, pure g-C3N4 and MR photocatalyst was fabricated as an photoelectrode and their oxygen evolution reaction(OER) activity was analyzed by electrochemical analysis techniques.

Manufacture and characterization of polymer concrete combining inorganic and organic fillers

Polymeric materials in the construction sector, together with inorganic and organic waste, are of great interest. Polymeric concretes have been prepared using a vinylester resin as a matrix and a combination of mineral (slate and granite) and organic (olive pits and hemp fibres) fillers, with the aim of studying the compatibility and the optimal dosages between the components, minimizing the amount of resin used and maximizing the mineral and organic waste. Scanning electron microscopy (SEM-EDX), X-ray diffraction (XRD) and X-ray fluorescence (WDXRF) have been used for the morphological, chemical and mineralogical characterization of the components and samples; hardness, compressive strength and flexural strength tests have been used to determine the mechanical properties. The results allow the adjustment of densification and mechanical behaviour. This will contribute to the valorization of agricultural and quarry waste, reduce the impact on the environment and improve production costs.

Monitoring the anticorrosion performance of developed epoxy-based paint formulations on metallic surfaces by electrochemical impedance spectroscopy

Purpose This study aims to investigate the impact of varying solid ratios in epoxy-based formulations on their corrosion resistance. The amounts of epoxy resin in the formulations were kept constant, and the behavior of paints with varying filler ratios was compared. It also examines the tensiometric and rheological properties of these formulations. Design/methodology/approach Three distinct epoxy-based formulations cured with amine compounds were prepared. The formulations underwent various testing protocols to evaluate their performance: coating tests: coated panels with cross lines were exposed to humidity and corrosive atmospheres. Tensiometric Measurements: Conducted using pendant and sessile drop methods. Rheological characterizations: ıncluded flow tests, oscillatory amplitude sweeps and three-interval thixotropy tests. Corrosion resistance assessment: after the panels were immersed in methanol for one week, measurements were taken using electrochemical impedance spectroscopy. Additional tests: neutral salt spray (NSS) and humidity testing. Findings The study observed that the coated panels, after exposure to NSS and humidity testing, demonstrated corrosion resistance within acceptable limits as defined by the ISO 12944-6 standard. Results indicate that the epoxy-based formulations show potential for improvements in paints and coatings, suggesting promising advancements in their anticorrosion performance. Originality/value This research provides insights into how the solid ratios in epoxy-based formulations influence their performance, particularly in terms of corrosion resistance, tensiometric and rheological properties. The findings contribute to the development of more effective epoxy resin-based coatings for industrial applications.

Effect of Epoxy Resin on the Strength Propery of Portland Cement Concrete

In this study, the strength effect of partially substituting Portland Cement (PC) with epoxy-resin in making concrete was examined. A mix ratio of 1:1.87:2.67 (PC: sand: granite chippings) at water-cement ratio of 0.5 targeting a strength of 30N/mm2 was adopted. The epoxy resin was mixed with hardener at a proportion of 1:0.5 and this mixture was used to replace PC at 10% intervals starting from 0% to 40%. Six cubes were cast for each mix ratio and were cured in water at room temperature for 28 days. The first set of samples were treated by heating them in an oven to a temperature of 1000C for 1 hour before testing in compression while, the other set were not treated. Results showed that as the quantity of epoxy resin in the concrete enlarged the compressive strength values reduced. But a rise was observed at 30%. All concrete produced were structural in nature except for the heated 40% specimen. An optimal replacement strength of 32.10 N/mm2 at 30% inclusion (unheated) and lowest strength of 18.63 N/mm2 at 40% replacement (heated) were obtained. The heated samples experienced further reduction in their compressive strength values. An 8.94% drop in strength was observed between the maximum replacement values for the heated and unheated samples at 30%. In conclusion, epoxy resin concrete can be used for structural works at replacement levels up to 40%. However, if the concrete will be exposed to increased temperature of 1000C, then an optimal replacement level of 30% is recommended.

Influence of Carbon Content on Element Diffusion in Silicon Carbide-Based TRISO Composite Fuel

The coating layers of Tri-structural Isotropic Particles (TRISO) serve to protect the kernel and act as barriers to fission products. Sintering aids in the silicon carbide matrix variably react with TRISO coating layers, leading to the destruction of the coating layers. Investigating how carbon content affects element diffusion in silicon carbide-based TRISO composite fuel is of great significance for predicting reactor safety. In this study, silicon carbide-based TRISO composite fuels with different carbon contents were prepared by adding varying amounts of phenolic resin to the silicon carbide matrix. X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM) were employed to characterize the phase composition, morphology, and microstructure of the composite fuels. The elemental content in each coating layer of TRISO was quantified using Energy-Dispersive X-ray Spectroscopy (EDS). The results demonstrated that the addition of phenolic resin promoted the uniform distribution of sintering aids in the silicon carbide matrix. The atomic percentage (at.%) of aluminum (Al) in the pyrolytic carbon layer of the TRISO particles reached its lowest value of 0.55% when the phenolic resin addition was 1%. This is because the addition of phenolic resin caused the Al and silicon (Si) in the matrix to preferentially react with the carbon in the phenolic resin to form a metastable liquid phase, rather than preferentially consuming the pyrolytic carbon in the outer coating layer of the TRISO particles. The findings suggest that carbon addition through phenolic resin incorporation can effectively mitigate the deleterious reactions between the TRISO coating layers and sintering aids, thereby enhancing the durability and safety of silicon carbide-based TRISO composite fuels.

Integrated deep eutectic solvent extraction and resin adsorption for recovering polyphenols from citrus reticulata Blanco peels: Process optimization, compositional analysis, and activity determination

Integrated deep eutectic solvent extraction and resin adsorption for recovering polyphenols from citrus reticulata Blanco peels: Process optimization, compositional analysis, and activity determination

Analysis of mechanical properties of basalt fabric reinforced fly ash filled vinyl ester composites using multi criteria decision making technique

Analysis of mechanical properties of basalt fabric reinforced fly ash filled vinyl ester composites using multi criteria decision making technique

Ketone modification of alkyd synthesized from waste PET as a sustainable option: A comparative study of coating and thermal properties of alkyd–melamine–ketone resin systems

AbstractThis study aims to prepare alkyd–melamine–ketone combinations from short‐oil alkyd resins synthesized using coconut oil fatty acid and waste poly(ethylene terephthalate) (PET) intermediate (bis(2‐hydroxyethyl) terephthalate, BHET) for coating applications with a green technology approach. For this aim, waste PET flakes obtained from post‐consumer water bottles were depolymerized by the glycolysis reaction. Purified depolymerization intermediate (BHET) was incorporated into the formulation of the four‐component alkyd resin, completely instead of the diol. For comparison, reference alkyds without waste PET were also synthesized. Then, ketone modifications of alkyd resins were carried out using cyclohexanone formaldehyde (CHF) resin by blending method. For this, firstly, melamine formaldehyde (MF) resin was added to the alkyd resin at a ratio of 40% by weight to obtain alkyd–melamine formaldehyde (Alkyd–MF) resin. Then, ketone‐modified blends were prepared at ratios of Alkyd–MF/CHF of 80/20, 70/30, 60/40, and 50/50 by weight. The effect of using ketone (CHF) resin at different ratios and the presence of BHET on the coating properties and thermal behaviors of alkyd–ketone blend films were investigated. At the end of the study, high‐gloss (151–154 GU) and medium‐hard (71–120 König second) films exhibiting excellent adhesion (100%) were obtained from alkyd–ketone blends. In both the reference and PET‐based blend series, adding CHF resin to the alkyd–amino (Alkyd–MF) resin improved all physical coating properties. Moreover, with increasing CHF resin ratios, hardness, gloss, and abrasion properties increased in both series. Although acceptable and usable results have been obtained in all ratios of CHF resin (20%, 30%, 40%, and 50%), the optimum CHF resin ratio for each physical coating properties has changed depending on the desired properties and expectations. These blend films resisted corrosive chemicals such as concentrated alkali, acid, and salt solutions for 72 h without damage, and at the end of the 18 h not affected by water. Acetone, toluene, methanol, and ethyl acetate did not affect these films in any way. All films performed excellently in repeated environmental resistance testing over 10 cycles, simulating changing climate conditions. In the chemical coating tests, superior results were obtained with all CHF resin ratios. The thermal resistance of Alkyd–MF/CHF blend films was found to be quite high. The incorporation of CHF resin into the alkyd–amino (Alkyd–MF) resin improved thermal resistance, and as the amount of CHF resin increased the thermal stability increased in both blend series. Moreover, the thermal resistance of PET‐based blend films was higher than their counterparts in reference blends due to the use of long‐chain BHET having an aromatic unit.Highlights Alkyd–MF/CHF blends using alkyds with and without PET were prepared. Good physical/excellent chemical coating properties/high thermal resistance. Incorporation of CHF into Alkyd–MF improved coating/thermal properties. CHF significantly improved the individual alkali resistances of the alkyd. As CHF increased, physical coating properties/thermal resistance increased. The thermal stabilities of the PET‐based blend were even higher.

Bioretention cells filled with epoxy resin-modified loess for stormwater purification

Bioretention cells filled with epoxy resin-modified loess for stormwater purification

THE EFFECT OF TREATING HEAVY OIL WITH ISOPROPYL ALCOHOL ON THE COMPOSITION AND STRUCTURE OF RESINS

The effect of heavy oil treatment with isopropyl alcohol (IPA) for 8 h at a temperature of 25-100 °C on the composition and structure of resins is investigated. The objects of investigation were heavy oil from the Zyuzeevskoye field (the Republic of Tatarstan) and resins isolated from this oil. It is established that the resin content increases by almost 3 wt% as a result of heavy oil treatment with IPA at 100 °C. It is shown than an increase in the temperature of oil - IPA (20 wt%) mixture treatment from 25 to 100 °C causes an increase in sulphur and oxygen content in resins by 0.5 and 0.8 wt%, respectively, and a decrease in the Н/С atomic ratio from 1.40 to 1.38. The aromaticity factor of resins increases by 0.17 %, while the fraction of aliphatic carbon decreases. It is concluded that oil treatment with isopropyl alcohol, aimed at a decrease in the content of resinous and asphaltenic substances, is unreasonable because it causes unfavourable formation of the additional amount of resins.

Trace amounts of silica and epoxy resin driven MXene-based flexible electrode coupled with good cycle stability

Trace amounts of silica and epoxy resin driven MXene-based flexible electrode coupled with good cycle stability

Preparation and characterization of ox bone powder and bamboo fibers reinforced hybrid epoxy composites

Composite materials are one of the fastest growing when compared with metal, ceramic, and polymer due to their high specific strength, stiffness, and versatile application in various fields. This study aimed to develop an ox bone powder and bamboo fiber-reinforced hybrid epoxy composite for stock and bumper applications and investigate the effect of the reinforcements on the composite’s mechanical properties. The reinforcements used in this work were random orientations of animal bone (ox) powder of 75 microns and bamboo fiber. The matrix used for this work was epoxy resin. Composite materials were prepared using the hand layup method with a 40% weight fraction of reinforcement (bone powder and bamboo fiber) and a 60% weight fraction of epoxy resin matrix. Five different combinations of bone powder and bamboo fiber with a fixed amount of epoxy resin were used for this work. The combinations of bamboo fiber and bone powder were: 40% bamboo fiber with 0% bone powder; 30% bamboo fiber with 10% bone powder; 20% bamboo fiber with 20% bone powder; and 0% bamboo fiber with 40% bone powder. The mechanical properties studied were compressive strength, impact strength, and flexural strength. In addition, water absorption was studied for all combinations. The maximum results of the flexural and impact strengths were 278.91 MPa and 7.5 J/m, respectively, at a 0:40 (bone powder: bamboo fiber) composite. The maximum compressive strength and the lowest absorption obtained were 283.3 MPa and 1.05%, respectively, at the 40:0 (bone powder: bamboo fiber) composite. For the hybrid composite case, optimal flexural and impact strengths were 236.72 MPa and 6.66 J/m, respectively, and water absorption was 1.52% at 10:30 (bone powder: bamboo fiber). Since reasonable flexural strength, impact strength, and water absorption were obtained with the hybrid composite of 10:30 (bone powder: bamboo fiber), this combination of the hybrid composite is recommended for stock and bumper applications.