Penetration Of Acid Research Articles

HT Stimulation Fluid Based On GLDA Meets Productivity, Environmental Need

Technology Update Industry operations are shifting toward high-temperature (HT) downhole set-tings, expensive tubular metallurgy, and extended reach wells, while health, safety, and environmental requirements become stricter. Consequently, conventional stimulation treatments, such as applications using hydrochloric acid-based fluids, will no longer meet the industry’s needs as operational environments evolve. A new stimulation fluid developed by AkzoNobel, Dissolvine StimWell, is based on glutamic acid diacetic acid (GLDA) and has been successfully applied in the field. GLDA has high thermal stability and low corrosion potential, and is an effective stimulation fluid without adverse environmental impact. A vertical gas well in a deep, sour carbonate reservoir was successfully stimulated using GLDA. Previous matrix stimulation treatments with conventional acids in this HT gas well did not sustain the performance, and a fracture treatment was considered for the well. However, the case proved that matrix acidizing with the GLDA-based fluid was the best stimulation method for the well in terms of cost-effectiveness and regulatory issues. Stimulation Purpose The object of stimulation is to remove the production zone damage caused by the drilling and completion processes in sandstone reservoirs, and to create channels or wormholes in carbonate reservoirs. Although an industry workhorse for decades, hydrochloric acid (HCl) often produces subpar stimulation results, especially at high temperatures, because of its fast reaction near the wellbore, low acid penetration, and high corrosivity. Many problems may occur during sandstone acidizing with HCl/hydrofluoric mud acid, such as decomposition of clays in HCl acids, precipitation caused by the presence of fluoride, silica gel filming, and colloidal silica gel precipitation. As a result, mud acid may cause significant damage to sandstone reservoirs, especially for those with a high content of calcite or clays such as illite. The desirable alternative stimulation fluid would be suitable for all of these conditions, be globally applicable, and have an acceptable environmental profile. Fluids based on GLDA meet those requirements. The fluids are effective in improving permeability in carbonate and sandstone formations. Many additives such as iron control agents that are required in other fluids are not needed in GLDA-based stimulation fluids.

Experimental Study and Reactive Transport Modeling of Boric Acid Leaching of Concrete

Borated water leakage through spent fuel pools (SFPs) at pressurized water reactors is a concern because it could cause corrosion of reinforcement steel in the concrete structure, compromise the integrity of the structure, or cause unmonitored releases of contaminated water to the environment. Experimental data indicate that pH is a critical parameter that determines the corrosion susceptibility of rebar in borated water and the degree of concrete degradation by boric acid leaching. In this study, reactive transport modeling of concrete leaching by borated water was performed to provide information on the solution pH in the concrete crack or matrix and the degree of concrete degradation at different locations of an SFP concrete structure exposed to borated water. Simulations up to 100 years were performed using different boric acid concentrations, crack apertures, and solution flow rates. Concrete cylinders were immersed in boric acid solutions for several months and the mineralogical changes and boric acid penetration in the concrete cylinder were evaluated as a function of time. The depths of concrete leaching by boric acid solution derived from the reactive transport simulations were compared with the measured boric acid penetration depth.

Transepidermal retinoic acid delivery using ablative fractional radiofrequency associated with acoustic pressure ultrasound for stretch marks treatment

Striae distensae (SD) treatment still remains a therapeutic challenge to dermatologists. Ablative fractional laser and radiofrequency (RF) enhance skin-drug permeability for SD treatment. To clinically evaluate the efficacy and safety as well as patient's satisfaction in relation to a method using ablative fractional RF associated with retinoic acid 0.05% cream and an acoustic pressure wave ultrasound (US) in patients with alba-type SD on the breast. Eight patients with alba-type SD on the breast were treated with three step procedure: (1) fractional ablative RF for skin perforation; (2) topical application of retinoic acid 0.05% on the perforated skin; and (3) US was applied to enhance the retinoic acid penetration into the skin. Other eight patients with alba-type SD on the abdominal area were submitted to RF treatment isolated without retinoic acid or US. Three of them were submitted to skin biopsies. Three patients with SD on the breast area improved from "severe" to "moderate;" two patients improved from "severe" to "mild;" two patients from "moderate" to "mild;" one patient from "marked" to "mild." Clinical assessment demonstrated significant improvement in the appearance of SD in all patients treated with RF associated with retinoic acid 0.05% cream and US (P = 0.008), with low incidence of side effects and high level of patient's satisfaction. Among the patients treated only with RF, two patients improved from "severe" to "marked;" one patient from "marked" to "moderate;" and one patient improved from "marked" to "mild." Four patients did not show any sort of improvement. Clinical assessment demonstrated no significant improvement in the appearance of SD treated with RF isolated with low incidence of side effects, but low-level of patient's satisfaction. Ablative fractional RF and acoustic pressure US associated with retinoic acid 0.05% cream is safe and effective for alba-type SD treatment.

Stability, transdermal penetration, and cutaneous effects of ascorbic acid and its derivatives

Topically applied antioxidants exert their benefits by offering protection from damaging free radicals and over-the-counter cosmeceuticals incorporating antioxidants are among the most popular anti-aging products available. One potent antioxidant of particular note, vitamin C, has been extensively utilized because it possesses a variety of other cutaneous benefits including photoprotection from UV A & B, neocollagenesis, inhibition of melanogenesis and improvement of a variety of inflammatory skin disorders. However, the instability of this water-soluble vitamin, together with difficulties associated with its topical delivery, has presented issues for the formulation chemist. This article reviews the scientific data and clinical studies that underpin the stability, percutaneous absorption, and cutaneous effects of vitamin C together with its commonly utilized, commercially available derivatives.

Biofilms of a Bacillus subtilis Hospital Isolate Protect Staphylococcus aureus from Biocide Action

The development of a biofilm constitutes a survival strategy by providing bacteria a protective environment safe from stresses such as microbicide action and can thus lead to important health-care problems. In this study, biofilm resistance of a Bacillus subtilis strain (called hereafter NDmedical) recently isolated from endoscope washer-disinfectors to peracetic acid was investigated and its ability to protect the pathogen Staphylococcus aureus in mixed biofilms was evaluated. Biocide action within Bacillus subtilis biofilms was visualised in real time using a non-invasive 4D confocal imaging method. The resistance of single species and mixed biofilms to peracetic acid was quantified using standard plate counting methods and their architecture was explored using confocal imaging and electronic microscopy. The results showed that the NDmedical strain demonstrates the ability to make very large amount of biofilm together with hyper-resistance to the concentration of PAA used in many formulations (3500 ppm). Evidences strongly suggest that the enhanced resistance of the NDmedical strain was related to the specific three-dimensional structure of the biofilm and the large amount of the extracellular matrix produced which can hinder the penetration of peracetic acid. When grown in mixed biofilm with Staphylococcus aureus, the NDmedical strain demonstrated the ability to protect the pathogen from PAA action, thus enabling its persistence in the environment. This work points out the ability of bacteria to adapt to an extremely hostile environment, and the necessity of considering multi-organism ecosystems instead of single species model to decipher the mechanisms of biofilm resistance to antimicrobials agents.

RNA and DNA Association to Zwitterionic and Charged Monolayers at the Air–Liquid Interface

The objective of this work is to establish under which conditions short RNA molecules (similar to miRNA) associate with zwitterionic phospholipids and how this differs from the association with cationic surfactants. We study how the base pairing (i.e., single stranded versus double stranded nucleic acids) and the length of the nucleic acid and the charge of the lipid/surfactant monolayer affect the association behavior. For this purpose, we study the adsorption of nucleic acids to monolayers composed of dipalmitoyl phosphatidylcholine (DPPC) or dioctadecyl-dimethyl-ammoniumbromide (DODAB) using the surface film balance, neutron reflectometry, and fluorescence microscopy. The monolayer studies with the surface film balance suggested that short single-stranded ssRNA associates with liquid expanded zwitterionic phospholipid monolayers, whereas less or no association is detected for double-stranded dsRNA and dsDNA. In order to quantify the interaction and to determine the location of the nucleic acid in the lipid/surfactant monolayer we performed neutron reflectometry measurements. It was shown that ssRNA adsorbs to and penetrates the liquid expanded monolayers, whereas there is no penetration of nucleic acids into the liquid condensed monolayer. No adsorption was detected for dsDNA to zwitterionic monolayers. On the basis of these results, we propose that the association is driven by the hydrophobic interactions between the exposed hydrophobic bases of the ssRNA and the hydrocarbon chains of the phospholipids. The addition of ssRNA also influences domain formation in the DPPC monolayer, leading to fractal-like interconnected domains. The experimental results are discussed in terms of the implication for biological processes and new leads for applications in medicine and biotechnology.

Template-Free Growth of Novel Hydroxyapatite Nanorings: Formation Mechanism and Their Enhanced Functional Properties

Template-free, single crystalline novel hydroxyapatite (HAp) nanorings with an inner diameter of 70 nm were grown by a combined high gravity and hydrothermal approach. Nanodisks were suggested to be formed by oriented aggregation and Ostwald ripening of mostly calcium pyrophosphate nanospheres prepared initially by the high gravity method with a stepwise increase of flow rate of phosphate solution. The prolonged hydrothermal treatment of nanodisks appeared to induce the nanoring formation via acid penetration along the dislocations in HAp nanodisks. The presence of edge dislocations in the central region of nanodisks was confirmed by high resolution transmission electron microscopy. The mechanical evaluation of high molecular weight polyethylene (HMWPE) composite with various shaped HAp nanocrystals and in vitro cellular analysis of HAp nanocrystals revealed that mechanical and bioactive performances improved with an increase of the specific surface area of HAp nanocrystals. The enhanced mechanical performance of HMWPE/HAp nanoring composite and the excellent cell viability for HAp nanorings are attributed to the superior interface bonding and cell activity, respectively, both of which are enhanced by the high specific surface area.

HCl/Formic In-Situ-Gelled Acids as Diverting Agents for Carbonate Acidizing

Summary In highly heterogeneous carbonate reservoirs, several acid systems have been used to enhance acid diversion during matrix acidizing such as surfactant-based acids and in-situ-gelled acids. In-situ-gelled acids are also used to reduce leakoff rate in acid fracturing. The main acid used in this system is hydrochloric acid (HCl). However, high reaction rates and severity of corrosion problems, especially for wells completed with Cr-based tubulars, limit the use of HCl at high temperatures. On the other hand, mixing organic acids with HCl either increases the acid penetration or reduces the necessary strength of HCl and the necessary load of the corrosion inhibitors. A few studies addressed the systems that use both advantages. The objective of this work is to investigate the behavior and the performance of different in-situ-gelled HCl/formic acid blends as diverting agents by conducting viscosity measurements, reaction-rate measurements using the rotating-disk apparatus, and through coreflood study. Formic acid was blended with HCl, and four in-situ-gelled acids were examined. Formic acid concentration varied from 0 to 6.31 wt%, and HCl concentration ranged from 0 to 5 wt%. Pink Desert limestone was used for reaction-rate and coreflood experiments. The rotating-disk apparatus was used to measure the reaction rate at 250°F at disk rotational speeds of 100 and 1,000 rev/min. The effect of formic acid concentration and zirconium crosslinking on the reaction rate was examined. Coreflood experiments were conducted at 250°F using two different rates of injection (2 and 10 cm3/min), and the core samples were imaged using a computed-tomography (CT) scan technique after each coreflood experiment. Increasing formic acid concentration decreased the reaction rate of in-situ-gelled HCl/formic acid with calcite at both low and high disk rotational speeds. This was confirmed by viscosity measurements, which showed that increasing formic acid concentration increased the viscosity of the live acids and decreased the viscosity of the spent acids. Coreflood results showed that increasing formic acid concentration in HCl/formic acid blends reduced acid ability for diversion. In the selected range of acid concentration and for the type of polymer and crosslinking agent used, the in-situ HCl/formic acid behaved more like gelled acid and reached a breakthrough in all coreflood experiments. The higher the formic acid concentration, the higher the pore volume of the acid required to break through.

The Use of Mammalian Cultured Cells Loaded with a Fluorescent Dye Shows Specific Membrane Penetration of Undissociated Acetic Acid

Acetic acid induces unique physiological responses in mammalian cells. Our previous study found that fura-2-loaded human embryonic kidney (HEK) 293T cells showed a robust intracellular fluorescence response immediately after stimulation with acetic acid, and no such response in the case of citric acid. In the present study, we aimed to identify the unique characteristics of acetic acid responsible for this phenomenon. We found that one such feature is its hydrophobicity. We also discovered that acetic acid induces cell responses by intracellular acidification. Of the components of acetic acid in solution (protons, acetate ions, and undissociated acetic acid), undissociated acetic acid might be the functional unit that penetrates the lipid bilayer of cell membranes to acidify the intracellular environment, thereby inducing cell responses. The method used in this study might be convenient in evaluating the intracellular acidification of cultured cells by acids in the external environment.

Evidence of 5-aminolevulinic acid (ALA) penetration increase due to microdrilling in soft tissue using femtosecond laser ablation

Photodynamic therapy (PDT) is a therapeutic technique mainly applied to the treatment of malignant and pre-malignant lesions, which induces cell death by the combined effect of a photosensitizer, irradiation in a proper wavelength, and molecular oxygen. One of the main limitations of PDT using 5-aminolevulinic acid (ALA) is the superficial volume of treatment, mainly due to the limited penetration of topical photosensitization. In this context, the present study investigates if a laser micromachining producing microchannels on the tissue surface could improve ALA penetration and result in an increase in the treatment depth. The laser micromachining under femtosecond regime was performed on the tissue surface of rat livers. Conventional PDT was applied and the induced depth of necrosis with or without laser micromachining was compared. The results showed an increase of more than 20% in the depth of necrosis when the femtosecond laser micromachining was performed before the treatment with the PDT.

Glove material, reservoir formation, and dose affect glove permeation and subsequent skin penetration

Protective gloves are used to reduce dermal exposure when managing chemical exposures at the work place. Different glove materials may offer different degrees of protection. The present study combined the traditional ASTM (American Society for Testing and Materials) model with the Franz diffusion cell to evaluate overall penetration through glove and skin as well as the deposition in the different reservoirs. Benzoic acid was applied on latex or nitrile gloves placed on top of human skin. The amounts of chemical were quantified in the glove material, between glove and skin, within the skin, and in the receptor chamber. Both glove materials reduce total penetration of benzoic acid, but nitrile gloves offer a significantly better protection than latex gloves. This difference was less pronounced at the higher of the two concentrations of benzoic acid applied. Thus, glove types that offer relevant protection at low concentrations does not necessarily give appropriate protection at high concentrations. Significant amounts of benzoic acid could be extracted from the glove materials after exposure. If a chemical is accumulated in the glove material, reuse of single-use gloves should be cautioned. The reuse of gloves is generally not to be recommended without effective decontamination.

Molecular Interactions of Alzheimer's Aβ Protofilaments with Lipid Membranes

Amyloid fibrils and peptide oligomers play central roles in the pathology of Alzheimer's disease, type 2 diabetes, Parkinson's disease, Huntington's disease, and prion-related disease. Here, we investigate the molecular interactions between preformed amyloid β (Aβ) molecular protofilaments and lipid bilayer membranes, in the presence of explicit water molecules, using computational models and all-atom molecular dynamics. These interactions play an important role in the stability and function of both Aβ fibrils and the adjacent cellular membrane. Taking advantage of the symmetry-related and directional properties of the protofilaments, we build models that cover several relative protofilament–membrane orientations. Our molecular dynamics simulations reveal the relative contributions of different structural elements to the dynamics and stability of Aβ protofilament segments near membranes, and the first steps in the mechanism of fibril–membrane interactions. During this process, we observe a significant alteration of the side-chain contact pattern in protofilaments, although a fraction of the characteristic β-sheet content is preserved. As a major driving force, we identify the electrostatic interactions between Aβ charged side chains, including E22, D23, and K28, and lipid headgroups. Together with hydrogen bonding with atoms from lipid headgroups, these interactions can facilitate the penetration of hydrophobic C-terminal amino acids through the lipid headgroup region, which can finally lead both to further loss of the initial fibril structure and to local membrane-thinning effects. Our results may guide new experiments that could test the extent to which the structural features of water-formed amyloid fibrils are preserved, lost, or reshaped by membrane-mediated interactions.

Leaching Mechanism of Cr(VI) from Chromite Ore Processing Residue with Nitric Acid

The leaching behavior of hexavalent chromium (Cr(VI)) and major metal elements relevant to Cr(VI) leaching from chromite ore processing residue (COPR) to HNO3 are investigated by batch leaching tests. According to the test results, aqueous Cr(VI) accounted for 70-80% of the content of total Cr. Cr(VI) concentration was controlled by the dissolution degree of Cr(VI)-bearing minerals (such as hydroandradite) as the pH value ranged from 7.58 to 10.47, and by the adsorption degree of Cr(VI) on metal amorphous precipitates as pH value ranged from 6.18 to 7.58. It takes time for the penetration of acid into COPR and the release of alkalinity from the interior zone of particles. So, it could be speculated that the fine-sized particles would react with acid more effectively. 14mol HNO3 per 1kg COPR is needed to maintain the pH value to achieve 7.5 for 48 hours. This indicates the acid neutralization capacity of the test sample is relatively large. It suggests that the application of acid treatment method for COPR disposal is feasible but costly.

Leaching Mechanism of Cr(VI) from Chromite Ore Processing Residue with Nitric Acid

The leaching behavior of hexavalent chromium (Cr(VI)) and major metal elements relevant to Cr(VI) leaching from chromite ore processing residue (COPR) to HNO3 are investigated by batch leaching tests. According to the test results, aqueous Cr(VI) accounted for 70-80% of the content of total Cr. Cr(VI) concentration was controlled by the dissolution degree of Cr(VI)-bearing minerals (such as hydroandradite) as the pH value ranged from 7.58 to 10.47, and by the adsorption degree of Cr(VI) on metal amorphous precipitates as pH value ranged from 6.18 to 7.58. It takes time for the penetration of acid into COPR and the release of alkalinity from the interior zone of particles. So, it could be speculated that the fine-sized particles would react with acid more effectively. 14mol HNO3 per 1kg COPR is needed to maintain the pH value to achieve 7.5 for 48 hours. This indicates the acid neutralization capacity of the test sample is relatively large. It suggests that the application of acid treatment method for COPR disposal is feasible but costly.

In Situ Hydrolysis of Imine Derivatives on Au(111) for the Formation of Aromatic Mixed Self-Assembled Monolayers: Multitechnique Analysis of This Tunable Surface Modification

This paper presents a novel method for preparing aromatic, mixed self-assembled monolayers (SAMs) with a dilute surface fraction coverage of protonated amine via in situ hydrolysis of C═N double bond on gold surface. Two imine compounds, (4'-(4-(trifluoromethyl)benzylideneamino)biphenyl-4-yl)methanethiol (CF(3)-C(6)H(4)-CH═N-C(6)H(4)-C(6)H(4)-CH(2)-SH, TFBABPMT) and (4'-(4-cyanobenzylideneamino)biphenyl-4-yl)methanethiol (CN-C(6)H(4)-CH═N-C(6)H(4)-C(6)H(4)-CH(2)-SH, CBABPMT), self-assembled on Au(111) to form highly ordered monolayers, which was demonstrated by infrared reflection absorption spectroscopy (IRRAS) and X-ray photoelectron spectroscopy (XPS). A nearly upright molecular orientation for CF(3)- and CN-terminated SAM was detected by near edge X-ray absorption fine structure (NEXAFS) measurements. Afterward, the acidic catalyzed hydrolysis was carried out in chloroform or an aqueous solution of acetic acid (pH = 3). Systematic studies of this hydrolysis process for CN-terminated SAM in acetic acid at 25 °C were performed by NEXAFS measurements. It was found that about 30% of the imine double bonds gradually cleaved in the first 40 min. Subsequently, a larger hydrolysis rate was observed due to the freer penetration of acetic acid in the SAM and resultant more open molecular packing. Furthermore, the molecular orientation in mixed SAMs did not change during the whole hydrolysis process. This partially hydrolyzed surface contains a controlled amount of free amines/ammonium ions which can be used for further chemical modifications.

Acid and salt uptake during the marinatig process of Engraulis anchoita fillets influence of the solution: fish ratio and agitation

The aims of this research were to determine the effect of different conditions of the marination stage on the salt and acid uptake, immersion time, and sensorial characteristics during the marinating process of anchovy (Engraulis anchoita). Different solution:fish ratios and the agitation effect during this stage were analyzed. The ratios used were: 0.77:1, 3:1 and 10:1 (with and without agitation). An increase of marinating solution:fish ratio causes a higher speed of acid and salt penetration The product obtained with the 10:1 ratio had a dry and fibrous texture and a slightly salty taste. Salt concentration was statistically significantly lower (p < 0.01) in the samples with agitation. Agitation did not influence the acid uptake, and the salt penetration speed decreased, but rancidity was detected in this product. The ratio 3:1 decreases the marinating time without damaging sensory attributes and can be used in the fish marinating process.

Effect of ionization and vehicle on skin absorption and penetration of azelaic acid

Objective: The aim of this study is to investigate the effect of ionization and vehicle of topical formulations on skin absorption and penetration of azelaic acid (AZA).Materials and methods: In vitro transport of AZA was determined for two topical formulations containing AZA with pH values of 3.9 and 4.9, respectively. FINACEA® (15% AZA gel), a US Food and Drug Administration approved drug for treatment of acne and rosacea, was also used for comparison. Release profile and flux of AZA were determined in an in vitro hairless mouse skin model using Franz Diffusion Cell.Results: The data have shown that a higher concentration of AZA is retained in the epidermis/dermis layer and the whole skin for the formulation with pH = 4.9 as compared to that with pH = 3.9 at an active loading level of 2.82 mg/cm2. In addition, the flux of ionized species of AZA in the pH 4.9 formulation (128.4 ± 35.9 μg/cm2/h) is approximately five-fold greater than that in the pH 3.9 formulation (27.7 ± 4.0 μg/cm2/h). The results suggest that the ionized AZA penetrates through the skin and accounts for majority of the total flux.Discussion and conclusion: This study has demonstrated that the penetration and absorption of AZA show a strong pH- and vehicle-dependency. Solubilization is the rate-limiting step in percutaneous absorption of AZA.

Cellular fusion and whitening effect of a chitosan derivative coated liposome

In this study, a derivative of chitosan, N-(2-hydroxyl) propyl-3-trimethyl ammonium chitosan chloride (HTCC), was coated onto the liposomes made of cholesterol and 1,2-palmitoyl-sn-glycero-3-phosphatidylcholine (DPPC). These coated liposomes were loaded with kojic acid for skin whitening. The appearance of liposome was examined using transmission electron microscope (TEM), and the coating of HTCC to the liposome was confirmed by infrared spectroscopy. By labeling with Dil, the fusion of liposome with the cell membrane of L929 fibroblast and B16-F10 melanoma was improved by the coating of HTCC. Based on the results of Franz cell experiment, the penetration of kojic acid (KA) through skin was improved by using HTCC-coating liposomes. Furthermore, the cell proliferation of L929 was not affected by HTCC-coating liposomes, while that of B16-F10 was reduced slightly with the increase of the concentration of HTCC-loading liposome. The degree of skin whitening was determined based on the melanin content in B-16-F10 cells. The results showed that the level of melanin synthesis was lower when KA was delivered using HTCC-coating liposome instead of traditional liposome.

Acid Leakoff Mechanism in Acid Fracturing of Naturally Fractured Carbonate Oil Reservoirs

In acid fracturing, excessive acid leakoff is thought to be the main reason that limits fracture propagation and live acid penetration distance. Since most carbonates are naturally fractured, we developed a new model in this paper to simulate acid leakoff into a naturally fractured carbonate oil reservoir during acid fracturing. Our model incorporates the acid-rock reaction, fracture width variation due to rock dissolution on the fractured surfaces, and fluid flow in naturally fractured carbonate oil reservoirs. Given the information of the reservoir, injected acid, and pressure in the hydraulic facture and the reservoir, the model predicts acid leakoff with time. In this study, we found that acid leakoff mechanism in naturally fractured carbonates is much different from that in reservoirs without natural fractures. Widened natural fractures by acid-rock reaction act as high-conductivity conduits allowing leakoff acid to penetrate deeper into the formation, resulting in serious leakoff. Wide natural fractures have a dominant effect on acid leakoff compared to micro-fractures and matrix.

A micromechanical study on longitudinal strength of fibrous composites exposed to acidic environment

In this study, a new model is presented to calculate longitudinal strength of unidirectional E-glass/epoxy composites exposed to sulfuric acid environment using the micromechanics theorem. Mechanical properties degradation of resin and fibers, acid penetration depth in the composites over the exposure times and thermal residual stresses are the main parameters affecting the strength of composites. Thus, corrosion tests are separately performed on the glass fibers and epoxy resin and their mechanical properties degradation are measured. The EDX (Energy Dispersive X-ray Microanalysis) analysis is then used to study the elements composition of glass fibers embedded in the composites. The results are utilized to calculate the acid penetration depth in the composites. Furthermore, thermal residual stresses are calculated in two different ways, the micromechanics theorem and a Representative Volume Element (RVE) model using the FEM method. Finally, the magnitude of strength of degraded composites is calculated with and without including thermal residual stresses. Compared to the experimental results, the strength results including thermal residual stresses calculated by the RVE model reveal the most accurate results.