This study is to determine the support mechanism of pre-stressed expandable props for the stope roof in room- and-pillar mining, which is crucial for maintaining stability and preventing roof collapse in mines. Utiliz...This study is to determine the support mechanism of pre-stressed expandable props for the stope roof in room- and-pillar mining, which is crucial for maintaining stability and preventing roof collapse in mines. Utilizing an engineering case from a gold mine in Dandong, China, a laboratory-based similar test is conducted to extract the actual roof characteristic curve. This test continues until the mining stope collapses due to a U-shaped failure. Concurrently, a semi-theoretical method for obtaining the roof characteristic curve is proposed and verified against the actual curve. The semi-theoretical method calculated that the support force and vertical displacement at the demarcation point between the elastic and plastic zones of the roof characteristic curve are 5.0 MPa and 8.20 mm, respectively, corroborating well with the laboratory-based similar test results of 0.22 MPa and 0.730 mm. The weakening factor for the plastic zone in the roof characteristic curve was semi-theoretically estimated to be 0.75. The intersection between the actual roof characteristic curve and the support characteristic curves of expandable props, natural pillars, and concrete props indicates that the expandable prop is the most effective “yielding support” for the stope roof in room-and-pillar mining. That is, the deformation and failure of the stope roof can be effectively controlled with proper release of roof stress. This study provides practical insights for optimizing support strategies in room-and-pillar mining, enhancing the safety and efficiency of mining operations.展开更多
The expandable graphite(EG)modified TiO_(2) nanocomposites were prepared by the high shearmethod using the TiO_(2) nanoparticles(NPs)and EG as precursors,in which the amount of EG doped in TiO_(2) was 10 wt.%.Followed...The expandable graphite(EG)modified TiO_(2) nanocomposites were prepared by the high shearmethod using the TiO_(2) nanoparticles(NPs)and EG as precursors,in which the amount of EG doped in TiO_(2) was 10 wt.%.Followed by the impregnation method,adjusting the pH of the solution to 10,and using the electrostatic adsorption to achieve spatial confinement,the Pt elementswere mainly distributed on the exposed TiO_(2),thus generating the Pt/10EG-TiO_(2)-10 catalyst.The best CO oxidation activity with the excellent resistance to H_(2)O and SO_(2) was obtained over the Pt/10EG-TiO_(2)-10 catalyst:CO conversion after 36 hr of the reaction was ca.85%under the harsh condition of 10 vol.%H_(2)O and 100 ppm SO_(2) at a high gaseous hourly space velocity(GHSV)of 400,000 hr−1.Physicochemical properties of the catalystswere characterized by various techniques.The results showed that the electrostatic adsorption,which riveted the Pt elements mainly on the exposed TiO_(2) of the support surface,reduced the dispersion of Pt NPs on EG and achieved the effective dispersion of Pt NPs,hence significantly improving CO oxidation activity over the Pt/10EG-TiO_(2)-10 catalyst.The 10 wt.%EG doped in TiO_(2) caused the TiO_(2) support to form a more hydrophobic surface,which reduced the adsorption of H_(2)O and SO_(2) on the catalyst,greatly inhibited deposition of the TiOSO_(4) and formation of the PtSO4 species as well as suppressed the oxidation of SO_(2),thus resulting in an improvement in the resistance to H_(2)O and SO_(2) of the Pt/10EG-TiO_(2)-10 catalyst.展开更多
Approximately 45 percent of malignant bone tumors are seen under the age of 16 and one of the important results of growth plate sacrification in patients with immature skeletons is limb inequality.Until the early 1990...Approximately 45 percent of malignant bone tumors are seen under the age of 16 and one of the important results of growth plate sacrification in patients with immature skeletons is limb inequality.Until the early 1990s,the treatment options for these patients were rotationplasty or amputation.Multimodal approaches that combine imaging,chemotherapy,and surgical techniques have enabled the development of limb-preserving methods with satisfactory results.In order to overcome inequality problems,expandable prostheses have been developed in the 1980s.Extendable endoprosthesis replacements have been improved over the years and are now an established and safe alternative.Noninvasive prostheses appear to be advantageous compared to minimally invasive expandable prostheses that require multiple surgical procedures,but the complication rate remains high.Therefore,although expandable prostheses are not the definitive answer to the treatment of bone sarcomas in skeletally immature children,they are still a suitable interim choice until full adulthood is achieved.Due to reported high complication rates,the procedures require significant experience and are recommended for use only in specialized cancer centers.展开更多
AIM： To describe a simple one-step method involving percutaneous transhepatic insertion of an expandable metal stent （EMS） used in the treatment of obstructive jaundice caused by unresectable malignancies. METHODS...AIM： To describe a simple one-step method involving percutaneous transhepatic insertion of an expandable metal stent （EMS） used in the treatment of obstructive jaundice caused by unresectable malignancies. METHODS： Fourteen patients diagnosed with obstructive jaundice due to unresectable malignancies were included in the study. The malignancies in these patients were a result of very advanced carcinoma or old age. Percutaneous transhepatic cholangiography was performed under ultrasonographic guidance. After a catheter with an inner metallic guide was advanced into the duodenum, an EMS was placed in the common bile duct, between a point 1 cm beyond the papilla of Vater and the entrance to the hepatic hilum. In cases where it was difficult to span the distance using just a single EMS, an additional stent was positioned. A drainage catheter was left in place to act as a hemostat. The catheter was removed after resolution of cholestasis and stent patency was confirmed 2 or 3 d post-procedure. RESULTS： One-step insertion of the EMS was achieved in all patients with a procedure mean time of 24.4 min. Out of the patients who required 2 EMS, 4 needed a procedure time exceeding 30 min. The mean time for removal of the catheter post-procedure was 2.3 d. All patients died of malignancy with a mean follow-up time of 7.8 mo. No stent-related complication or stent obstruction was encountered. CONCLUSIONS： One-step percutaneous transhepaticinsertion of EMS is a simple procedure for resolving biliary obstruction and can effectively improve the patient＇s quality of life.展开更多
In this paper, thermoexpandable polymeric microspheres were prepared by suspension polymerization with acrylonitrile （AN） and methyl methacrylate （MMA） as monomers and/-butane as a blowing agent. The micromorpholo...In this paper, thermoexpandable polymeric microspheres were prepared by suspension polymerization with acrylonitrile （AN） and methyl methacrylate （MMA） as monomers and/-butane as a blowing agent. The micromorphology and thermal stability were researched by polarized microscopy and TGA. The diameter of the expandable microspheres increased from about 20μm （unexpanded） to 40-80 μm （expanded） upon heating. The maximum expansion volume was higher than 22 times of the original volume and the density of the expanded microspheres was about 16.7 kg/m3. The blowing agent content in microspheres was about 20 wt% and To.e., Tm.e. and To.s. were 80℃, 120-130℃ and 140-145℃, respectively.展开更多
This paper aims to determine the load bearing capacity of pre-stressed expandable props with different geometries and load eccentricities for flexible support in underground mining or excavation.It is deduced that the...This paper aims to determine the load bearing capacity of pre-stressed expandable props with different geometries and load eccentricities for flexible support in underground mining or excavation.It is deduced that the expandable device could have much higher strength(>89 MPa)by laboratory tests,and the load bearing capacity of the expandable prop may depend on the stability of the supporting steel pipe structure.A good agreement was found between the laboratory test and numerical results in terms of the load bearing capacity and the final macro-bending failure pattern for expandable props with heights of 1.5 and 2.7 m,and the theoretical calculation for the strength of traditional steel structures is not directly suitable for the expandable props.Moreover,additional numerical simulations were performed for the expandable props with different normalized slenderness ratiosλ_(n)and loading eccentric distances e.The variation of stability coefficient of the expandable prop is in line with the Perry-Robertson equation and its correlation coefficients are fitted as a of 0.979 and b of 0.314.For estimating the load bearing capacity of the expandable props,the strength equation for traditional steel structures is improved by introducing a bending magnification factor and by modifying the normalized slenderness ratio to a converted slenderness ratio.Based on the underground field monitoring for the strength of expandable props with different heights,the empirical eccentric distances were back calculated,and a safety factor is introduced to obtain the designed strength of the expandable prop.In addition,a four-step design procedure is proposed for the expandable prop.展开更多
Cellular foams are widely applied as protective and energy absorption materials in both civil and military fields. A facile and simple one-step heating method to fabricate polymeric foams is measured by adopting therm...Cellular foams are widely applied as protective and energy absorption materials in both civil and military fields. A facile and simple one-step heating method to fabricate polymeric foams is measured by adopting thermally expandable microspheres(TEMs). The ideal foaming parameters for various density foams were determined. Moreover, a mechanical testing machine and split Hopkinson bar(SHPB) were utilized to explore the quasi-static and dynamic compressive properties. Results showed that the cell sizes of the as-prepared TEMs foams were in the micrometer range of 11 μm to 20 μm with a uniform cell size distribution. All the foams exhibited good compressive behavior under both quasi-static and high strain rate conditions, and were related to both foam densities and strain rates. The compressive strength of the TEMs foams at 8400s^(-1) was up to 4 times higher than that at 10^(-4)s^(-1). The effects exerted by the strain rate and sample density were evaluated by a power law equation. With increasing density, the strain rate effect was more prominent. At quasistatic strain rates below 3000s^(-1) regime, initial cell wall buckling and subsequent cellular structure flattening were the main failure mechanisms. However, in the high strain rate(HSR) regime(above 5000s^(-1)), the foams were split into pieces by the following transverse inertia force.展开更多
AIM:To investigate and evaluate the technical feasibility and clinical effectiveness of fluoroscopically guided peroral uncovered expandable metal stent placement to treat gastric outlet and duodenal obstructions. MET...AIM:To investigate and evaluate the technical feasibility and clinical effectiveness of fluoroscopically guided peroral uncovered expandable metal stent placement to treat gastric outlet and duodenal obstructions. METHODS:Fifteen consecutive patients underwent peroral placement of Wallstent^(TM)Enteral Endoprosthesis to treat gastric outlet and duodenal obstructions(14 malignant,1 benign).All procedures were completed under fluoroscopic guidance without endoscopic assistance.Follow-up was completed until the patients died or were lost,and the clinical outcomes were analyzed. RESULTS:The technique success rate was 100%,and the oral intake was maintained in 12 of 14 patients varying from 7 d to 270 d.Two patients remained unable to resume oral intake,although their stents were proven to be patent with the barium study.One patient with acute necrotizing pancreatitis underwent enteral stenting to treat intestinal obstruction,and nausea and vomiting disappeared.Ten patients died during the follow- up period,and their mean oral intake time was 50 d. No procedure-related complications occurred.Stent migration to the gastric antrum occurred in one patient 1 year after the procedure,a tumor grew at the proximal end of the stent in another patient 38 d post-stent insertion. CONCLUSION:Fluoroscopically guided peroral metal stent implantation is a safe and effective method to treat malignant gastrointestinal obstructions,and complications can be ignored based on our short-term study.Indications for this procedure should be discreetly considered because a few patients may not benefit from gastrointestinal insertion,but some benign gastrointestinal obstructions can be treated using this procedure.展开更多
Vanadium redox flow battery(VRFB)is one of the most promising large-scale energy storage systems,which ranges from kilowatt to megawatt.Nevertheless,poor electrochemical activity of electrode for two redox couples sti...Vanadium redox flow battery(VRFB)is one of the most promising large-scale energy storage systems,which ranges from kilowatt to megawatt.Nevertheless,poor electrochemical activity of electrode for two redox couples still restricts the extensive applications of VRFB.Compared with V^(2+)/V^(3+)redox reaction,V^(2+)/V^(3+)reaction plays a more significant role in voltage loss of VRFB owing to slow heterogeneous electron transfer rate.Herein,N-doped carbon materials derived from scaphium scaphigerum have been developed as negative electrocatalyst by hydrothermal carbonization and high-temperature nitridation treatments.The undoped carbon material hardly has electrocatalytic ability for V^(2+)/V^(3+)reaction.Based on this,N-doped carbon materials with urea as nitrogen source exhibit excellent electrocatalytic properties.And the material nitrided at 850°C(SSC/N-850)exhibits the best performance among those from700 to 1000℃.SSC/N-850 can accelerate the electrode process including V^(2+)/V^(3+)reaction and mass transfer of active ions due to the large reaction place,more active sites,and good hydrophilicity.The effect of catalyst on comprehensive performance of cell was evaluated.SSC/N-850 can improve the charge-discharge performance greatly.Utilization of SSC/N-850 can lessen the electrochemical polarization of cell,further resulting in increased discharge capacity and energy efficiency.Discharge capacity and energy efficiency increase by 81.5%and 9.8%by using SSC/N-850 as negative catalyst at 150 m A cm^(-2),respectively.Our study reveals that the developed biomass-derived carbon materials are the low-cost and efficient negative electrocatalyst for VRFB system.展开更多
Endoscopic ultrasound-guided drainage has recently been recommended for increasing the drainage rate of endoscopically managed pancreatic fluid collections and decreasing the morbidity associated with conventional end...Endoscopic ultrasound-guided drainage has recently been recommended for increasing the drainage rate of endoscopically managed pancreatic fluid collections and decreasing the morbidity associated with conventional endoscopic trans-mural drainage. The type of stent used for endoscopic drainage is currently a major area of interest. A covered self expandable metallic stent (CSEMS) is an alternative to conventional drainage with plastic stents because it offers the option of providing a larger-diameter access fi stula for drainage, and may increase the fi nal success rate. One problem with CSEMS is dislodgement, so a metallic stent with flared or looped ends at both extremities may be the best option. An 85-year-old woman with severe comorbidity was treated with percutaneous approach for a large (20 cm) pancreatic pseudocyst with corpuscolated material inside. This approach failed. The patient was transferred to our institute for EUS-guided transmural drainage. EUS confi rmed a large, anechoic cyst with hyperechoic material inside. Because the cyst was large and contained mixed and corpusculated fluid, we used a metallic stent for drainage. To avoid migration of the stent and potential mucosal growth above the stent, a plastic prosthesis (7 cm, 10 Fr) with flaps at the tips was inserted inside the CSEMS. Two months later an esophagogastroduodenoscopy was done, and showed patency of the SEMS and plastic stents, which were then removed with a polypectomy snare. The patient experienced no further problems.展开更多
The corrosion behavior of expandable tubular materials was investigated in simulated downhole formation water environments using a series of electrochemical techniques. The corrosion morphologies in the real downhole ...The corrosion behavior of expandable tubular materials was investigated in simulated downhole formation water environments using a series of electrochemical techniques. The corrosion morphologies in the real downhole environment after three months of application were also observed by stereology microscopy and scanning electron microscopy （SEM）. The results show that, compared with the unex- panded sample, the area of ferfite increases dramatically after a 7.09% expansion. The expanded material shows a higher corrosion current in the polarization curve and a lower corrosion resistance in the electrochemical impedance spectroscopy （EIS） plot at every studied tempera- ture. The determined critical pitting temperatures （CPT） before and after expansion are 87.5℃and 79.2℃, respectively. SEM observations demonstrate stress corrosion cracks, and CO2 corrosion and H2S corrosion also occur in the downhole environment. Due to additional defects generated during the plastic deformation, the corrosion performance of the expanded tubing deteriorates.展开更多
In this study, a series of flame-retardant polyisocyanurate-polyurethane (PIR-PUR) foams were prepared using various concentrations (0-25% by weight) of expandable graphite (EG) and dimethyl methyl phosphonate (DMMP) ...In this study, a series of flame-retardant polyisocyanurate-polyurethane (PIR-PUR) foams were prepared using various concentrations (0-25% by weight) of expandable graphite (EG) and dimethyl methyl phosphonate (DMMP) (0-7% by weight). The effect of these additives on the properties of the PIR-PUR foams, including physico-mechanical, morphological, flame retardancy, and thermal stability, was studied. Increasing amounts of EG in the PIR-PUR foam caused a significant drop in the compression strength. However, DMMP caused the mechanical properties of PIR-PUR foam to improve compared to foam filled with EG alone. The flame retardancy of PIR-PUR foams containing both EG and DMMP was enhanced significantly compared to EG filled foams. Thermogravimetric analysis (TGA) indicated that EG enhances the thermal stability of PIR-PUR foams but that DMMP decreased it. The morphology of the residual char provided conclusive evidence for the weak thermal stability of foams filled with DMMP.展开更多
The thermally expandable microspheres（TEMs） were prepared via suspension polymerization with acrylonitrile（AN）, methyl methacrylate（MMA） and methyl acrylate（MA） as monomers and n-hexane as the blowing agent. M...The thermally expandable microspheres（TEMs） were prepared via suspension polymerization with acrylonitrile（AN）, methyl methacrylate（MMA） and methyl acrylate（MA） as monomers and n-hexane as the blowing agent. Meanwhile, a novel type of functional and conductive thermal expandable microsphere was obtained through strongly covering the surface of microsphere by conductive polymers with the mass loading of 1.5%. The optimal conditions to prepare high foaming ratio and equally distributed microcapsules were investigated with AN-MMA-MA in the proportion of 70%/20%/10%（m/m/m）, and 25 wt% of n-hexane in oil phase. The further investigation results showed that the unexpanded TEMs were about 30 μm in diameter and the maximum expansion ratio was nearly 125 times of original volume. The polypyrrole（PPy） was smoothly coated on the surface of the TEMs and the expansion property of PPy-coated TEMs was almost the same as the uncoated TEMs. Moreover, the structure and expanding performance of TEMs and PPy-coated TEMs were characterized by scanning electron microscopy（SEM）, laser particle size analyzer and dilatometer（DIL）.展开更多
In this paper,we introduced a novel method to prepare the few-layer nitrogen-doped graphene(FNG)from expandable graphite with melamine.The super-capacitive properties of FNG were thoroughly characterized by a three-el...In this paper,we introduced a novel method to prepare the few-layer nitrogen-doped graphene(FNG)from expandable graphite with melamine.The super-capacitive properties of FNG were thoroughly characterized by a three-electrode system,and the results showed the FNG electrode achieved a specific capacitance as high as 83.8 mF/cm2 together with excellent cycling stability.This method could be a novel approach to combine the pseudo-capacitors and electric double layer capacitors.展开更多
In this study,orthogonal experiments were conducted to investigate the influence of expandable graphite(EG),dimethyl methylphosphonate(DMMP),triethanolamine(TEA),and isocyanate content on the compressive and bonding s...In this study,orthogonal experiments were conducted to investigate the influence of expandable graphite(EG),dimethyl methylphosphonate(DMMP),triethanolamine(TEA),and isocyanate content on the compressive and bonding strengths,oxygen index,and fluidity of rigid polyurethane foam(RPUF).The results revealed that EG significantly increased the oxygen index of RPUF,enlarged the diameter of foam cells,and decreased the cell-closed content in foam;thus,leading to a pressure drop in RPUF.However,excessive EG was capable of reducing the fluidity of polyurethane slurry.TEA exhibited significant influence on the compressive strength of RPUF,which dropped initially,and then increased.DMMP had a remarkable effect on the flame retardant property and compressive strength of RPUF.Compressive strength of RPUF initially displayed an increase followed by a decrease with increasing dosage of DMMP,and achieved the maximum value at DMMP dosage of 4%.DMMP could effectively reduce the diameter of RPUF cells leading to an increase in the percentage of close area in foam.DMMP displayed the flame-retardation effects mainly in the gas phase leading to a significant enhancement in the oxygen index of RPUF.Moreover,the compressive strength and bonding strength of RPUF decrease significantly with the increase of isocyanate content due to the increased blowing efficiency by the CO_2.The oxygen index and flowing length of foam increased with the increase in isocyanate dosage.展开更多
A novel expandable conductor was designed and applied in deep-water drilling to improve the vertical and lateral bearing capacity with a significant reduction of conductor jetting depth and soaking time. The vertical ...A novel expandable conductor was designed and applied in deep-water drilling to improve the vertical and lateral bearing capacity with a significant reduction of conductor jetting depth and soaking time. The vertical and lateral bearing capability of expandable conductors was depicted based on the ultimate subgrade reaction method and pile foundation bearing theory. The load-bearing characteristics of a laboratory-scale expandable conductor were analyzed through laboratory experiments. The serial simulation experiments are accomplished to study the bearing characteristics(vertical ultimate bearing capacity, lateral soil pressure, and lateral displacement) during the conductor soaking process. The laboratory experimental results show that the larger the length and thickness of expandable materials are,the higher the bearing capacity of the wellhead will be. During the conductor soaking process, the soil pressure around the three expandable conductors increases faster, strings representing a stronger squeezing effect and resulting in higher vertical bearing capacity. Furthermore, the lateral displacement of novel expandable conductor is smaller than that of the conventional conductor. All the advantages mentioned above contributed to the reduction of conductor’s jetting depth and soaking time. Lastly, the application workflow of a novel expandable deep-water drilling conductor was established and the autonomous expandable conductor was successfully applied in the South China Sea with a significant reduction of conductor’s jetting depth and soaking time. According to the soil properties and designed installation depth of the surface conductor, the arrangement of expandable materials should be designed reasonably to meet the safety condition and reduce the construction cost of the subsea wellhead.展开更多
In this article,two kinds of expandable parallel finite element methods,based on two-grid discretizations,are given to solve the linear elliptic problems.Compared with the classical local and parallel finite element m...In this article,two kinds of expandable parallel finite element methods,based on two-grid discretizations,are given to solve the linear elliptic problems.Compared with the classical local and parallel finite element methods,there are two attractive features of the methods shown in this article:1)a partition of unity is used to generate a series of local and independent subproblems to guarantee the final approximation globally continuous;2)the computational domain of each local subproblem is contained in a ball with radius of O(H)(H is the coarse mesh parameter),which means methods in this article are more suitable for parallel computing in a large parallel computer system.Some a priori error estimation are obtained and optimal error bounds in both H^1-normal and L^2-normal are derived.Finally,numerical results are reported to test and verify the feasibility and validity of our methods.展开更多
We present an in-depth study of the failure phenomenon of solid expandable tubular (SET) due to large expansion ratio in open holes of deep and ultra-deep wells. By examining the post-expansion SET, lots of microcrack...We present an in-depth study of the failure phenomenon of solid expandable tubular (SET) due to large expansion ratio in open holes of deep and ultra-deep wells. By examining the post-expansion SET, lots of microcracks are found on the inner surface of SET. Their morphology and parameters such as length and depth are investigated by use of metallographic microscope and scanning electron microscope (SEM). In addition, the Voronoi cell technique is adopted to characterize the multi-phase material microstructure of the SET. By using the anisotropic elastoplastic material constitutive model and macro/microscopic multi-dimensional cross-scale coupled boundary conditions, a sophisticated and multi-scale finite element model (FEM) of the SET is built successfully to simulate the material microstructure damage for different expansion ratios. The microcrack initiation and growth is simulated, and the structural integrity of the SET is discussed. It is concluded that this multi-scale finite element modeling method could effectively predict the elastoplastic deformation and the microscopic damage initiation and evolution of the SET. It is of great significance as a theoretical analysis tool to optimize the selection of appropriate tubular materials and it could be also used to substantially reduce costly failures of expandable tubulars in the field. This numerical analysis is not only beneficial for understanding the damage process of tubular materials but also effectively guides the engineering application of the SET technology.展开更多
This work reports on the effect of commercial expandable graphite(EG)on the flammability and thermal decomposition properties of PLA-starch blend.The PLA-starch/EG composites were prepared by melt-mixing and their the...This work reports on the effect of commercial expandable graphite(EG)on the flammability and thermal decomposition properties of PLA-starch blend.The PLA-starch/EG composites were prepared by melt-mixing and their thermal stability,volatile pyrolysis products and flammability characteristics were investigated.The char residues of the composites,after combustion in a cone calorimeter,were analyzed with environmental scanning electron microscopy(ESEM).The thermal decomposition stability of the composites improved in the presence of EG.However,the char content was less than expected as per the combination of the wt%EG added into PLA-starch and the%residue of PLA-starch.The flammability performance of the PLA-starch/EG composites improved,especially at 15 wt%EG content,due to a thick and strong worm-like char structure.The peak heat release rate(PHRR)improved by 74%,the total smoke production(TSP)by 40%and the specific extinction area(SEA)by 55%.The improvements are attributed to the ability of EG to exfoliate at increased temperatures during which time three effects occurred:(i)cooling due to an endothermic exfoliation process,(ii)dilution due to release of H2O,SO2 and CO2 gases,and (iii)formation of a protective intumescent char layer.However,the CO and CO2 yields were found to be unfavorably high due to the presence of EG.展开更多
Adhesives are used to bond various substrates such as metals, polymers, ceramics, rubber, wood and wood-based products. The use of adhesive as bonding agent rather than mechanical fasteners like nails results in the p...Adhesives are used to bond various substrates such as metals, polymers, ceramics, rubber, wood and wood-based products. The use of adhesive as bonding agent rather than mechanical fasteners like nails results in the potential for reduced cost and weight of assemblies. However, adhesives are unprotected to a wide range of conditions, such as thermo-mechanical cycling in the environment, creep and fatigue imposed by structural joint configurations, and residual stress due to mismatch of thermal expansion between adhesives and objects. Thus, there will be a need for development of new chemistries and processes for easy repair and reprocessing of bonded structures are becoming of current great interest for the industries. In some cases, to improve the protection of various items/objects during handling and transportation, currently used protective products such as padded wraps, envelopes, packages and containers need to be modified. One technology which can solve the problem is the adhesives modified with thermally expandable particles (TEPs) which can be dismounted by heating the joint in a few seconds. The expandable composition is providing the necessary protective insulation and cushioning required in packages and containers. This paper reviews the application of unexpanded microspheres in the adhesive segment.展开更多
基金Project(2022YFC2903801) supported by the National Key Research and Development Program of ChinaProjects(52374117, 52274115) supported by the National Natural Science Foundation of China。
文摘This study is to determine the support mechanism of pre-stressed expandable props for the stope roof in room- and-pillar mining, which is crucial for maintaining stability and preventing roof collapse in mines. Utilizing an engineering case from a gold mine in Dandong, China, a laboratory-based similar test is conducted to extract the actual roof characteristic curve. This test continues until the mining stope collapses due to a U-shaped failure. Concurrently, a semi-theoretical method for obtaining the roof characteristic curve is proposed and verified against the actual curve. The semi-theoretical method calculated that the support force and vertical displacement at the demarcation point between the elastic and plastic zones of the roof characteristic curve are 5.0 MPa and 8.20 mm, respectively, corroborating well with the laboratory-based similar test results of 0.22 MPa and 0.730 mm. The weakening factor for the plastic zone in the roof characteristic curve was semi-theoretically estimated to be 0.75. The intersection between the actual roof characteristic curve and the support characteristic curves of expandable props, natural pillars, and concrete props indicates that the expandable prop is the most effective “yielding support” for the stope roof in room-and-pillar mining. That is, the deformation and failure of the stope roof can be effectively controlled with proper release of roof stress. This study provides practical insights for optimizing support strategies in room-and-pillar mining, enhancing the safety and efficiency of mining operations.
基金supported by the National Key R&D Program of China (No.2017YFC0210303).
文摘The expandable graphite(EG)modified TiO_(2) nanocomposites were prepared by the high shearmethod using the TiO_(2) nanoparticles(NPs)and EG as precursors,in which the amount of EG doped in TiO_(2) was 10 wt.%.Followed by the impregnation method,adjusting the pH of the solution to 10,and using the electrostatic adsorption to achieve spatial confinement,the Pt elementswere mainly distributed on the exposed TiO_(2),thus generating the Pt/10EG-TiO_(2)-10 catalyst.The best CO oxidation activity with the excellent resistance to H_(2)O and SO_(2) was obtained over the Pt/10EG-TiO_(2)-10 catalyst:CO conversion after 36 hr of the reaction was ca.85%under the harsh condition of 10 vol.%H_(2)O and 100 ppm SO_(2) at a high gaseous hourly space velocity(GHSV)of 400,000 hr−1.Physicochemical properties of the catalystswere characterized by various techniques.The results showed that the electrostatic adsorption,which riveted the Pt elements mainly on the exposed TiO_(2) of the support surface,reduced the dispersion of Pt NPs on EG and achieved the effective dispersion of Pt NPs,hence significantly improving CO oxidation activity over the Pt/10EG-TiO_(2)-10 catalyst.The 10 wt.%EG doped in TiO_(2) caused the TiO_(2) support to form a more hydrophobic surface,which reduced the adsorption of H_(2)O and SO_(2) on the catalyst,greatly inhibited deposition of the TiOSO_(4) and formation of the PtSO4 species as well as suppressed the oxidation of SO_(2),thus resulting in an improvement in the resistance to H_(2)O and SO_(2) of the Pt/10EG-TiO_(2)-10 catalyst.
文摘Approximately 45 percent of malignant bone tumors are seen under the age of 16 and one of the important results of growth plate sacrification in patients with immature skeletons is limb inequality.Until the early 1990s,the treatment options for these patients were rotationplasty or amputation.Multimodal approaches that combine imaging,chemotherapy,and surgical techniques have enabled the development of limb-preserving methods with satisfactory results.In order to overcome inequality problems,expandable prostheses have been developed in the 1980s.Extendable endoprosthesis replacements have been improved over the years and are now an established and safe alternative.Noninvasive prostheses appear to be advantageous compared to minimally invasive expandable prostheses that require multiple surgical procedures,but the complication rate remains high.Therefore,although expandable prostheses are not the definitive answer to the treatment of bone sarcomas in skeletally immature children,they are still a suitable interim choice until full adulthood is achieved.Due to reported high complication rates,the procedures require significant experience and are recommended for use only in specialized cancer centers.
文摘AIM： To describe a simple one-step method involving percutaneous transhepatic insertion of an expandable metal stent （EMS） used in the treatment of obstructive jaundice caused by unresectable malignancies. METHODS： Fourteen patients diagnosed with obstructive jaundice due to unresectable malignancies were included in the study. The malignancies in these patients were a result of very advanced carcinoma or old age. Percutaneous transhepatic cholangiography was performed under ultrasonographic guidance. After a catheter with an inner metallic guide was advanced into the duodenum, an EMS was placed in the common bile duct, between a point 1 cm beyond the papilla of Vater and the entrance to the hepatic hilum. In cases where it was difficult to span the distance using just a single EMS, an additional stent was positioned. A drainage catheter was left in place to act as a hemostat. The catheter was removed after resolution of cholestasis and stent patency was confirmed 2 or 3 d post-procedure. RESULTS： One-step insertion of the EMS was achieved in all patients with a procedure mean time of 24.4 min. Out of the patients who required 2 EMS, 4 needed a procedure time exceeding 30 min. The mean time for removal of the catheter post-procedure was 2.3 d. All patients died of malignancy with a mean follow-up time of 7.8 mo. No stent-related complication or stent obstruction was encountered. CONCLUSIONS： One-step percutaneous transhepaticinsertion of EMS is a simple procedure for resolving biliary obstruction and can effectively improve the patient＇s quality of life.
基金supported by Shandong Provincial Natural Science Foundation,China (No.ZR2013EMM004)
文摘In this paper, thermoexpandable polymeric microspheres were prepared by suspension polymerization with acrylonitrile （AN） and methyl methacrylate （MMA） as monomers and/-butane as a blowing agent. The micromorphology and thermal stability were researched by polarized microscopy and TGA. The diameter of the expandable microspheres increased from about 20μm （unexpanded） to 40-80 μm （expanded） upon heating. The maximum expansion volume was higher than 22 times of the original volume and the density of the expanded microspheres was about 16.7 kg/m3. The blowing agent content in microspheres was about 20 wt% and To.e., Tm.e. and To.s. were 80℃, 120-130℃ and 140-145℃, respectively.
基金This work was financially supported by the National Key Research and Development Program of China(No.2022YFC2903804)the National Natural Science Foundation of China(Nos.52004054,52274115,51874068 and 52074062).
文摘This paper aims to determine the load bearing capacity of pre-stressed expandable props with different geometries and load eccentricities for flexible support in underground mining or excavation.It is deduced that the expandable device could have much higher strength(>89 MPa)by laboratory tests,and the load bearing capacity of the expandable prop may depend on the stability of the supporting steel pipe structure.A good agreement was found between the laboratory test and numerical results in terms of the load bearing capacity and the final macro-bending failure pattern for expandable props with heights of 1.5 and 2.7 m,and the theoretical calculation for the strength of traditional steel structures is not directly suitable for the expandable props.Moreover,additional numerical simulations were performed for the expandable props with different normalized slenderness ratiosλ_(n)and loading eccentric distances e.The variation of stability coefficient of the expandable prop is in line with the Perry-Robertson equation and its correlation coefficients are fitted as a of 0.979 and b of 0.314.For estimating the load bearing capacity of the expandable props,the strength equation for traditional steel structures is improved by introducing a bending magnification factor and by modifying the normalized slenderness ratio to a converted slenderness ratio.Based on the underground field monitoring for the strength of expandable props with different heights,the empirical eccentric distances were back calculated,and a safety factor is introduced to obtain the designed strength of the expandable prop.In addition,a four-step design procedure is proposed for the expandable prop.
基金financially supported by the National Natural Science Foundation of China(Nos.51572208 and 51521001)the National Key R&D Program of China(No.2018YFB0905600)+2 种基金the 111 Project(No.B13035)the China Postdoctoral Science Foundation(No.2018M632935)the Nature Science Foundation of Hubei Province(No.2016CFA006)
文摘Cellular foams are widely applied as protective and energy absorption materials in both civil and military fields. A facile and simple one-step heating method to fabricate polymeric foams is measured by adopting thermally expandable microspheres(TEMs). The ideal foaming parameters for various density foams were determined. Moreover, a mechanical testing machine and split Hopkinson bar(SHPB) were utilized to explore the quasi-static and dynamic compressive properties. Results showed that the cell sizes of the as-prepared TEMs foams were in the micrometer range of 11 μm to 20 μm with a uniform cell size distribution. All the foams exhibited good compressive behavior under both quasi-static and high strain rate conditions, and were related to both foam densities and strain rates. The compressive strength of the TEMs foams at 8400s^(-1) was up to 4 times higher than that at 10^(-4)s^(-1). The effects exerted by the strain rate and sample density were evaluated by a power law equation. With increasing density, the strain rate effect was more prominent. At quasistatic strain rates below 3000s^(-1) regime, initial cell wall buckling and subsequent cellular structure flattening were the main failure mechanisms. However, in the high strain rate(HSR) regime(above 5000s^(-1)), the foams were split into pieces by the following transverse inertia force.
文摘AIM:To investigate and evaluate the technical feasibility and clinical effectiveness of fluoroscopically guided peroral uncovered expandable metal stent placement to treat gastric outlet and duodenal obstructions. METHODS:Fifteen consecutive patients underwent peroral placement of Wallstent^(TM)Enteral Endoprosthesis to treat gastric outlet and duodenal obstructions(14 malignant,1 benign).All procedures were completed under fluoroscopic guidance without endoscopic assistance.Follow-up was completed until the patients died or were lost,and the clinical outcomes were analyzed. RESULTS:The technique success rate was 100%,and the oral intake was maintained in 12 of 14 patients varying from 7 d to 270 d.Two patients remained unable to resume oral intake,although their stents were proven to be patent with the barium study.One patient with acute necrotizing pancreatitis underwent enteral stenting to treat intestinal obstruction,and nausea and vomiting disappeared.Ten patients died during the follow- up period,and their mean oral intake time was 50 d. No procedure-related complications occurred.Stent migration to the gastric antrum occurred in one patient 1 year after the procedure,a tumor grew at the proximal end of the stent in another patient 38 d post-stent insertion. CONCLUSION:Fluoroscopically guided peroral metal stent implantation is a safe and effective method to treat malignant gastrointestinal obstructions,and complications can be ignored based on our short-term study.Indications for this procedure should be discreetly considered because a few patients may not benefit from gastrointestinal insertion,but some benign gastrointestinal obstructions can be treated using this procedure.
基金financially supported by the National Natural Science Foundation of China(No.51772097)Hebei Natural Science Fund for Distinguished Young Scholar(No.E2019209433)Training Program of Innovation and Entrepreneurship for Undergraduates(No.X2018156,North China University of Science and Technology)。
文摘Vanadium redox flow battery(VRFB)is one of the most promising large-scale energy storage systems,which ranges from kilowatt to megawatt.Nevertheless,poor electrochemical activity of electrode for two redox couples still restricts the extensive applications of VRFB.Compared with V^(2+)/V^(3+)redox reaction,V^(2+)/V^(3+)reaction plays a more significant role in voltage loss of VRFB owing to slow heterogeneous electron transfer rate.Herein,N-doped carbon materials derived from scaphium scaphigerum have been developed as negative electrocatalyst by hydrothermal carbonization and high-temperature nitridation treatments.The undoped carbon material hardly has electrocatalytic ability for V^(2+)/V^(3+)reaction.Based on this,N-doped carbon materials with urea as nitrogen source exhibit excellent electrocatalytic properties.And the material nitrided at 850°C(SSC/N-850)exhibits the best performance among those from700 to 1000℃.SSC/N-850 can accelerate the electrode process including V^(2+)/V^(3+)reaction and mass transfer of active ions due to the large reaction place,more active sites,and good hydrophilicity.The effect of catalyst on comprehensive performance of cell was evaluated.SSC/N-850 can improve the charge-discharge performance greatly.Utilization of SSC/N-850 can lessen the electrochemical polarization of cell,further resulting in increased discharge capacity and energy efficiency.Discharge capacity and energy efficiency increase by 81.5%and 9.8%by using SSC/N-850 as negative catalyst at 150 m A cm^(-2),respectively.Our study reveals that the developed biomass-derived carbon materials are the low-cost and efficient negative electrocatalyst for VRFB system.
文摘Endoscopic ultrasound-guided drainage has recently been recommended for increasing the drainage rate of endoscopically managed pancreatic fluid collections and decreasing the morbidity associated with conventional endoscopic trans-mural drainage. The type of stent used for endoscopic drainage is currently a major area of interest. A covered self expandable metallic stent (CSEMS) is an alternative to conventional drainage with plastic stents because it offers the option of providing a larger-diameter access fi stula for drainage, and may increase the fi nal success rate. One problem with CSEMS is dislodgement, so a metallic stent with flared or looped ends at both extremities may be the best option. An 85-year-old woman with severe comorbidity was treated with percutaneous approach for a large (20 cm) pancreatic pseudocyst with corpuscolated material inside. This approach failed. The patient was transferred to our institute for EUS-guided transmural drainage. EUS confi rmed a large, anechoic cyst with hyperechoic material inside. Because the cyst was large and contained mixed and corpusculated fluid, we used a metallic stent for drainage. To avoid migration of the stent and potential mucosal growth above the stent, a plastic prosthesis (7 cm, 10 Fr) with flaps at the tips was inserted inside the CSEMS. Two months later an esophagogastroduodenoscopy was done, and showed patency of the SEMS and plastic stents, which were then removed with a polypectomy snare. The patient experienced no further problems.
基金financially supported by the National Natural Science Foundation of China(No.51222106)the Fundamental Research Funds for the Central Universities of China(No.FRF-TP-14-011C1)
文摘The corrosion behavior of expandable tubular materials was investigated in simulated downhole formation water environments using a series of electrochemical techniques. The corrosion morphologies in the real downhole environment after three months of application were also observed by stereology microscopy and scanning electron microscopy （SEM）. The results show that, compared with the unex- panded sample, the area of ferfite increases dramatically after a 7.09% expansion. The expanded material shows a higher corrosion current in the polarization curve and a lower corrosion resistance in the electrochemical impedance spectroscopy （EIS） plot at every studied tempera- ture. The determined critical pitting temperatures （CPT） before and after expansion are 87.5℃and 79.2℃, respectively. SEM observations demonstrate stress corrosion cracks, and CO2 corrosion and H2S corrosion also occur in the downhole environment. Due to additional defects generated during the plastic deformation, the corrosion performance of the expanded tubing deteriorates.
基金supported by the State Key Program of Coal Joint Funds of National Natural Science Foundation of China (No.51134020)the Natural Science Foundation of Shandong Province(No. ZR2011EL036)the High School Science & Technology Fund Planning Project of Shandong Province (No. JIILD53)
文摘In this study, a series of flame-retardant polyisocyanurate-polyurethane (PIR-PUR) foams were prepared using various concentrations (0-25% by weight) of expandable graphite (EG) and dimethyl methyl phosphonate (DMMP) (0-7% by weight). The effect of these additives on the properties of the PIR-PUR foams, including physico-mechanical, morphological, flame retardancy, and thermal stability, was studied. Increasing amounts of EG in the PIR-PUR foam caused a significant drop in the compression strength. However, DMMP caused the mechanical properties of PIR-PUR foam to improve compared to foam filled with EG alone. The flame retardancy of PIR-PUR foams containing both EG and DMMP was enhanced significantly compared to EG filled foams. Thermogravimetric analysis (TGA) indicated that EG enhances the thermal stability of PIR-PUR foams but that DMMP decreased it. The morphology of the residual char provided conclusive evidence for the weak thermal stability of foams filled with DMMP.
基金the National Natural ScienceFoundation of China(Nos.21206171,21376010)the Project of Natural Science Foundation of Beijing(No.2152012)+1 种基金the Young Elite Teacher Project(No.27170115004/027)the Project of 2011 Collaborative Innovation for Green Printing and Publishing Technology and the Project of Beijing Municipal Commission of Educatio (No.km201410005007)for the financial supports
文摘The thermally expandable microspheres（TEMs） were prepared via suspension polymerization with acrylonitrile（AN）, methyl methacrylate（MMA） and methyl acrylate（MA） as monomers and n-hexane as the blowing agent. Meanwhile, a novel type of functional and conductive thermal expandable microsphere was obtained through strongly covering the surface of microsphere by conductive polymers with the mass loading of 1.5%. The optimal conditions to prepare high foaming ratio and equally distributed microcapsules were investigated with AN-MMA-MA in the proportion of 70%/20%/10%（m/m/m）, and 25 wt% of n-hexane in oil phase. The further investigation results showed that the unexpanded TEMs were about 30 μm in diameter and the maximum expansion ratio was nearly 125 times of original volume. The polypyrrole（PPy） was smoothly coated on the surface of the TEMs and the expansion property of PPy-coated TEMs was almost the same as the uncoated TEMs. Moreover, the structure and expanding performance of TEMs and PPy-coated TEMs were characterized by scanning electron microscopy（SEM）, laser particle size analyzer and dilatometer（DIL）.
基金supported by the National Natural Science Foundation of China(Nos.21271082 and 21371068)。
文摘In this paper,we introduced a novel method to prepare the few-layer nitrogen-doped graphene(FNG)from expandable graphite with melamine.The super-capacitive properties of FNG were thoroughly characterized by a three-electrode system,and the results showed the FNG electrode achieved a specific capacitance as high as 83.8 mF/cm2 together with excellent cycling stability.This method could be a novel approach to combine the pseudo-capacitors and electric double layer capacitors.
基金supported by the National Natural Science Foundation of China(No.51304027)China Postdoctoral Science Foundation(2014M560567 and 2015T80730)+4 种基金Shandong Province Science and Technology Development Plan(2014GSF120012)the State Key Program of Coal Joint Funds of National Natural Science Foundation of China(Nos.51134020 and U1261205)Shandong Province Natural Science Foundation(No.ZR2011EL036)the Doctoral Scientific Research Foundation of Binzhou University(No.2013Y06)the Key Technology Projects for Preventing Major Accident of National Security State Administration of Work Safety
文摘In this study,orthogonal experiments were conducted to investigate the influence of expandable graphite(EG),dimethyl methylphosphonate(DMMP),triethanolamine(TEA),and isocyanate content on the compressive and bonding strengths,oxygen index,and fluidity of rigid polyurethane foam(RPUF).The results revealed that EG significantly increased the oxygen index of RPUF,enlarged the diameter of foam cells,and decreased the cell-closed content in foam;thus,leading to a pressure drop in RPUF.However,excessive EG was capable of reducing the fluidity of polyurethane slurry.TEA exhibited significant influence on the compressive strength of RPUF,which dropped initially,and then increased.DMMP had a remarkable effect on the flame retardant property and compressive strength of RPUF.Compressive strength of RPUF initially displayed an increase followed by a decrease with increasing dosage of DMMP,and achieved the maximum value at DMMP dosage of 4%.DMMP could effectively reduce the diameter of RPUF cells leading to an increase in the percentage of close area in foam.DMMP displayed the flame-retardation effects mainly in the gas phase leading to a significant enhancement in the oxygen index of RPUF.Moreover,the compressive strength and bonding strength of RPUF decrease significantly with the increase of isocyanate content due to the increased blowing efficiency by the CO_2.The oxygen index and flowing length of foam increased with the increase in isocyanate dosage.
基金financially supported by the National Natural Science Foundation of China (Grant Nos.51434009 and 51221003)。
文摘A novel expandable conductor was designed and applied in deep-water drilling to improve the vertical and lateral bearing capacity with a significant reduction of conductor jetting depth and soaking time. The vertical and lateral bearing capability of expandable conductors was depicted based on the ultimate subgrade reaction method and pile foundation bearing theory. The load-bearing characteristics of a laboratory-scale expandable conductor were analyzed through laboratory experiments. The serial simulation experiments are accomplished to study the bearing characteristics(vertical ultimate bearing capacity, lateral soil pressure, and lateral displacement) during the conductor soaking process. The laboratory experimental results show that the larger the length and thickness of expandable materials are,the higher the bearing capacity of the wellhead will be. During the conductor soaking process, the soil pressure around the three expandable conductors increases faster, strings representing a stronger squeezing effect and resulting in higher vertical bearing capacity. Furthermore, the lateral displacement of novel expandable conductor is smaller than that of the conventional conductor. All the advantages mentioned above contributed to the reduction of conductor’s jetting depth and soaking time. Lastly, the application workflow of a novel expandable deep-water drilling conductor was established and the autonomous expandable conductor was successfully applied in the South China Sea with a significant reduction of conductor’s jetting depth and soaking time. According to the soil properties and designed installation depth of the surface conductor, the arrangement of expandable materials should be designed reasonably to meet the safety condition and reduce the construction cost of the subsea wellhead.
基金Subsidized by NSFC (11701343)partially supported by NSFC (11571274,11401466)
文摘In this article,two kinds of expandable parallel finite element methods,based on two-grid discretizations,are given to solve the linear elliptic problems.Compared with the classical local and parallel finite element methods,there are two attractive features of the methods shown in this article:1)a partition of unity is used to generate a series of local and independent subproblems to guarantee the final approximation globally continuous;2)the computational domain of each local subproblem is contained in a ball with radius of O(H)(H is the coarse mesh parameter),which means methods in this article are more suitable for parallel computing in a large parallel computer system.Some a priori error estimation are obtained and optimal error bounds in both H^1-normal and L^2-normal are derived.Finally,numerical results are reported to test and verify the feasibility and validity of our methods.
基金Project supported by the National Major Science & Technology Project of China (Grant No. 2016ZX05020-003).
文摘We present an in-depth study of the failure phenomenon of solid expandable tubular (SET) due to large expansion ratio in open holes of deep and ultra-deep wells. By examining the post-expansion SET, lots of microcracks are found on the inner surface of SET. Their morphology and parameters such as length and depth are investigated by use of metallographic microscope and scanning electron microscope (SEM). In addition, the Voronoi cell technique is adopted to characterize the multi-phase material microstructure of the SET. By using the anisotropic elastoplastic material constitutive model and macro/microscopic multi-dimensional cross-scale coupled boundary conditions, a sophisticated and multi-scale finite element model (FEM) of the SET is built successfully to simulate the material microstructure damage for different expansion ratios. The microcrack initiation and growth is simulated, and the structural integrity of the SET is discussed. It is concluded that this multi-scale finite element modeling method could effectively predict the elastoplastic deformation and the microscopic damage initiation and evolution of the SET. It is of great significance as a theoretical analysis tool to optimize the selection of appropriate tubular materials and it could be also used to substantially reduce costly failures of expandable tubulars in the field. This numerical analysis is not only beneficial for understanding the damage process of tubular materials but also effectively guides the engineering application of the SET technology.
文摘This work reports on the effect of commercial expandable graphite(EG)on the flammability and thermal decomposition properties of PLA-starch blend.The PLA-starch/EG composites were prepared by melt-mixing and their thermal stability,volatile pyrolysis products and flammability characteristics were investigated.The char residues of the composites,after combustion in a cone calorimeter,were analyzed with environmental scanning electron microscopy(ESEM).The thermal decomposition stability of the composites improved in the presence of EG.However,the char content was less than expected as per the combination of the wt%EG added into PLA-starch and the%residue of PLA-starch.The flammability performance of the PLA-starch/EG composites improved,especially at 15 wt%EG content,due to a thick and strong worm-like char structure.The peak heat release rate(PHRR)improved by 74%,the total smoke production(TSP)by 40%and the specific extinction area(SEA)by 55%.The improvements are attributed to the ability of EG to exfoliate at increased temperatures during which time three effects occurred:(i)cooling due to an endothermic exfoliation process,(ii)dilution due to release of H2O,SO2 and CO2 gases,and (iii)formation of a protective intumescent char layer.However,the CO and CO2 yields were found to be unfavorably high due to the presence of EG.
文摘Adhesives are used to bond various substrates such as metals, polymers, ceramics, rubber, wood and wood-based products. The use of adhesive as bonding agent rather than mechanical fasteners like nails results in the potential for reduced cost and weight of assemblies. However, adhesives are unprotected to a wide range of conditions, such as thermo-mechanical cycling in the environment, creep and fatigue imposed by structural joint configurations, and residual stress due to mismatch of thermal expansion between adhesives and objects. Thus, there will be a need for development of new chemistries and processes for easy repair and reprocessing of bonded structures are becoming of current great interest for the industries. In some cases, to improve the protection of various items/objects during handling and transportation, currently used protective products such as padded wraps, envelopes, packages and containers need to be modified. One technology which can solve the problem is the adhesives modified with thermally expandable particles (TEPs) which can be dismounted by heating the joint in a few seconds. The expandable composition is providing the necessary protective insulation and cushioning required in packages and containers. This paper reviews the application of unexpanded microspheres in the adhesive segment.
