Combined Optimal Dispatch of Thermal Power Generators and Energy Storage Considering Thermal Power Deep Peak Clipping and Wind Energy Emission Grading Punishment

Peak load and wind energy emission pressure rise more as wind energy penetration keeps growing,which affects the stabilization of the PS(power system).This paper suggests integrated optimal dispatching of thermal power generators and BESS(battery energy storage system)taking wind energy emission grading punishment and deep peak clipping into consideration.Firstly,in order to minimize wind abandonment,a hierarchical wind abandonment penalty strategy based on fuzzy control is designed and introduced,and the optimal grid-connected power of wind energy is determined as a result of minimizing the peak cutting cost of the system.Secondly,considering BESS and thermal power,the management approach of BESS-assisted virtual peak clipping of thermal power generators is aimed at reducing the degree of deep peak clipping of thermal power generators and optimizing the output of thermal power generators and the charging and discharging power of BESS.Finally,Give an example of how this strategy has been effective in reducing abandonment rates by 0.66% and 7.46% individually for different wind penetration programs,and the daily average can reduce the peak clipping power output of thermal power generators by 42.97 and 72.31 MWh and enhances the effect and economy of system peak clipping.

High-grade pancreatic intraepithelial neoplasia diagnosed based on changes in magnetic resonance cholangiopancreatography findings:A case report

BACKGROUND High-grade pancreatic intraepithelial neoplasia(PanIN)exhibits no mass and is not detected by any examination modalities.However,it can be diagnosed by pancreatic juice cytology from indirect findings.Most previous cases were diagnosed based on findings of a focal stricture of the main pancreatic duct(MPD)and caudal MPD dilatation and subsequent pancreatic juice cytology using endoscopic retrograde cholangiopancreatography(ERCP).We experienced a case of high-grade PanIN with an unclear MPD over a 20-mm range,but without caudal MPD dilatation on magnetic resonance cholangiopancreatography(MRCP).CASE SUMMARY A 60-year-old female patient underwent computed tomography for a follow-up of uterine cancer post-excision,which revealed pancreatic cysts.MRCP revealed an unclear MPD of the pancreatic body at a 20-mm length without caudal MPD dilatation.Thus,course observation was performed.After 24 mo,MRCP revealed an increased caudal MPD caliber and a larger pancreatic cyst.We performed ERCP and detected atypical cells suspected of adenocarcinoma by serial pancreatic juice aspiration cytology examination.We performed a distal pancreatectomy and obtained a histopathological diagnosis of high-grade PanIN.Pancreatic parenchyma invasion was not observed,and curative resection was achieved.CONCLUSION High-grade Pan-IN may cause MPD narrowing in a long range without caudal MPD dilatation.

Large Conventional Osteosarcoma of the Proximal Humerus in a 13-Year-Old Child: Case Report

Introduction: Osteosarcoma is the most common primary malignant bone tumor in children. It is highly aggressive and has a poor prognosis. A late presentation modifies and makes difficult the management affecting the survival of children. We report the case of a large conventional osteosarcoma in a 13-year-old girl. Case Presentation: Adolescent girl admitted for painful swelling of the left shoulder with absolute functional impotence of the thoracic limb and severe anemia. The painful swelling was thought to have been caused by a minor trauma that had occurred six months previously. The patient’s general condition was poor, and she presented with a large, shiny, painful mass over the shoulder and upper 2/3 of the left arm, measuring 28 cm long by 28 cm wide and 57 cm in circumference, and a large fistulous axillary adenopathy. CT scan showed a tumour lesion of the left humerus with liver and lung metastases, raising suspicion of osteogenic osteosarcoma. The tumor was classified according to TNM staging: T2N1M1(a + b). Management was modified when uncontrolled bleeding developed. It consisted of an extended amputation of the left thoracic limb. Pathological analysis showed a high-grade conventional osteosarcoma. Quality improvement was obtained for thirty days, followed by the onset of dyspnea. The evolution was towards death at forty days post-operatively. Conclusion: Osteosarcoma is a highly aggressive cancer. Delayed treatment leads to a fatal outcome. Early diagnosis is one of the challenges to be met in order to improve survival.

C-CORE:Clustering by Code Representation to Prioritize Test Cases in Compiler Testing

Edge devices,due to their limited computational and storage resources,often require the use of compilers for program optimization.Therefore,ensuring the security and reliability of these compilers is of paramount importance in the emerging field of edge AI.One widely used testing method for this purpose is fuzz testing,which detects bugs by inputting random test cases into the target program.However,this process consumes significant time and resources.To improve the efficiency of compiler fuzz testing,it is common practice to utilize test case prioritization techniques.Some researchers use machine learning to predict the code coverage of test cases,aiming to maximize the test capability for the target compiler by increasing the overall predicted coverage of the test cases.Nevertheless,these methods can only forecast the code coverage of the compiler at a specific optimization level,potentially missing many optimization-related bugs.In this paper,we introduce C-CORE(short for Clustering by Code Representation),the first framework to prioritize test cases according to their code representations,which are derived directly from the source codes.This approach avoids being limited to specific compiler states and extends to a broader range of compiler bugs.Specifically,we first train a scaled pre-trained programming language model to capture as many common features as possible from the test cases generated by a fuzzer.Using this pre-trained model,we then train two downstream models:one for predicting the likelihood of triggering a bug and another for identifying code representations associated with bugs.Subsequently,we cluster the test cases according to their code representations and select the highest-scoring test case from each cluster as the high-quality test case.This reduction in redundant testing cases leads to time savings.Comprehensive evaluation results reveal that code representations are better at distinguishing test capabilities,and C-CORE significantly enhances testing efficiency.Across four datasets,C-CORE increases the average of the percentage of faults detected(APFD)value by 0.16 to 0.31 and reduces test time by over 50% in 46% of cases.When compared to the best results from approaches using predicted code coverage,C-CORE improves the APFD value by 1.1% to 12.3% and achieves an overall time-saving of 159.1%.

Anti-EGFR antibody monotherapy for colorectal cancer with severe hyperbilirubinemia: A case report

BACKGROUND Hyperbilirubinemia with hepatic metastases is a common complication and a poor prognostic factor for colorectal cancer(CRC).Effective drainage is often im-possible before initiating systemic chemotherapy,owing to the liver’s diffuse metastatic involvement.Moreover,an appropriate chemotherapeutic approach for the treatment of hyperbilirubinemia is currently unavailable.CASE SUMMARY The patient,a man in his 50s,presented with progressive fatigue and severe jaundice.Computed tomography revealed multiple hepatic masses with thick-ened walls in the sigmoid colon,which was pathologically confirmed as a well-differentiated adenocarcinoma.No RAS or BRAF mutations were detected.The Eastern Cooperative Oncology Group(ECOG)performance status(PS)score was 2.Biliary drainage was impossible due to the absence of a dilated bile duct,and panitumumab monotherapy was promptly initiated.Subsequently,the bilirubin level decreased and then normalized,and the patient’s PS improved to zero ECOG score after four cycles of therapy without significant adverse events.CONCLUSION Anti-EGFR antibody monotherapy is a safe and effective treatment for RAS wild-type CRC and hepatic metastases with severe hyperbilirubinemia.

Concurrent occurrence of adenocarcinoma and urothelial carcinoma of the prostate gland:A case report

BACKGROUND Adenocarcinoma is the most common subtype of prostate cancer.Prostatic urothelial carcinoma(UC)typically originates from the prostatic urethra.The concurrent occurrence of adenocarcinoma and UC of the prostate gland is uncommon.CASE SUMMARY We present the case of an 82-year-old male patient with simultaneous adenocarcinoma and UC of the prostate gland.The patient underwent a transrectal ultrasound-guided biopsy,and the pathology test revealed UC.Subsequently,transurethral laser prostatectomy was performed,and the pathology test indicated adenocarcinoma of the prostate with a Gleason score of 3+4 and highgrade UC.Therefore,the patient was treated with androgen deprivation therapy,systemic chemotherapy,and immunotherapy.Magnetic resonance imaging performed during follow-up revealed a prostate tumor classified as cT2cN1M0,stage IVA.Therefore,the patient underwent robotic-assisted radical prostatectomy and bilateral pelvic lymph node dissection.The final pathology test of the prostate gland revealed acinar-type adenocarcinoma,Gleason pattern 4+3,pT2N0M0,and high-grade UC.The patient regularly presented to the clinic for postoperative follow-up evaluations.He did not experience any urinary discomfort.CONCLUSION According to our literature review,this is the first reported case of coexisting adenocarcinoma and UC of the prostate gland.

Analysis and monitoring of drug therapy in a patient with peptic ulcer complicated by infection:A case report

BACKGROUND The role of primary-level medical pharmacists in medical institutions in China is limited;therefore,it is necessary to explore the role of pharmacists in the process of drug treatment.CASE SUMMARY A Chinese pharmacist participated in the complete treatment of a patient with a duodenal ulcer.The rationale for drug treatment was evaluated,and adjustments were made to the antacid and anti-infective regimen,as well as the dose and frequency of administration.Body temperature,routine blood examination,and adverse drug reactions were strictly monitored.During treatment,the pharmacist recommended anti-infective therapy with ampicillin-sulbactam,which effectively controlled the infection.Additionally,the pharmacist suggested changing famotidine to lansoprazole for acid suppression and gastroprotective treatment,combined with Chinese patent medicine such as Kangfuxin Liquid.This is the first case report of a pharmacist in primary-level medical institutions adjusting drug use for patients with duodenal ulcer and pulmonary infection.CONCLUSION A pharmacist participated in the treatment process,provided individualized medication adjustment,and achieved good clinical results.

Mimicking aneurysm in a patient with chronic occlusion of the left middle cerebral artery:A case report

BACKGROUND With the popularization of various cerebrovascular imaging methods and increased attention to the field,more cerebrovascular diseases are being detected in asymptomatic patients.Different cerebrovascular diseases are typically isolated but occasionally occur simultaneously,causing difficulties in diagnosis and treatment.Morphological changes in the collateral circulation of blood vessels in chronic cerebral artery occlusion patients are slow and dynamic,intercepting morphological development at a specific moment.Excessive reliance on single imaging tests such as digital subtraction cerebral angiography(DSA)can lead to misdiagnosis.CASE SUMMARY We report a 52-year-old male who was admitted to our department for treatment of an unruptured aneurysm during a follow-up examination for brain trauma after 1 mo.Computed tomography(CT)scan was negative,but CT angiography(CTA)revealed a sac-like bulge at the bifurcation of the left middle cerebral artery.DSA revealed an unruptured aneurysm with unique scapular morphology.The stump of a middle cerebral artery occlusion was observed during exposure during aneurysm clipping surgery,and the diagnosis of chronic cerebral artery occlusion was confirmed intraoperatively.This case was confusing because of the peculiar morphology of the arterial stump and compensatory angiogenesis due to multiple cerebral artery stenoses observed on preoperative CTA and DSA.The surgery did not cause secondary damage to the patient,and medical treatment for risk factors was continued postoperatively.CONCLUSION Multiple cerebral arterial stenoses can occur in conjunction with aneurysms or arteriovenous malformations,and their unique morphology can lead to misdiagnosis.

Early adenocarcinoma mixed with a neuroendocrine carcinoma component arising in the gastroesophageal junction: A case report

BACKGROUND Early adenocarcinoma mixed with a neuroendocrine carcinoma(NEC)component arising in the gastroesophageal junctional(GEJ)region is rare and even rarer in young patients.Here,we report such a case in a 29-year-old Chinese man.CASE SUMMARY This patient presented to our hospital with a 3-mo history of dysphagia and regurgitation.Upper endoscopy revealed an elevated nodule in the distal esophagus 1.6 cm above the GEJ line,without Barrett’s esophagus or involvement of the gastric cardia.The nodule was completely resected by endoscopic submu-cosal dissection(ESD).Pathological examination confirmed diagnosis of intra-mucosal adenocarcinoma mixed with an NEC component,measuring 1.5 cm.Immunohistochemically,both adenocarcinoma and NEC components were positive for P53 with a Ki67 index of 90%;NEC was positive for synaptophysin and chromogranin.Next-generation sequencing of 196 genes demonstrated a novel germline mutation of the ERCC3 gene in the DNA repair pathway and a germline mutation of the RNF43 gene,a common gastric cancer driver gene,in addition to pathogenic somatic mutations in P53 and CHEK2 genes.The patient was alive without evidence of the disease 36 mo after ESD.CONCLUSION Early adenocarcinoma with an NEC component arising in the distal esophageal side of the GEJ region showed evidence of gastric origin.

Epithelioid malignant peripheral nerve sheath tumor of the bladder and concomitant urothelial carcinoma: A case report

BACKGROUND Epithelioid malignant peripheral nerve sheath tumor(EMPNST)of the bladder is a rare entity with devastating features.These tumors are thought to originate from malignant transformation of pre-existing schwannomas of pelvic autonomic nerve plexuses,and unlike the conventional malignant peripheral nerve sheath tumor(MPNST),are not associated with neurofibromatosis.The tumor has dis-tinctive morphological,immunohistochemical and molecular features.Addi-tionally,it tends to be more aggressive and have a higher mortality.This is the first case that presents with a synchronous urothelial carcinoma of the bladder and the epithelioid variant of MPNST in the literature.It’s also the second re-ported case of EMPNST originating from the bladder wall.CASE SUMMARY In this case report,we present the detailed clinical course of a 71-year-old patient with EMPNST of the bladder alongside a literature review.CONCLUSION During the management of EMPNST cases,offering aggressive treatment moda-lities to the patient,such as radical cystectomy,is appropriate for the best chance to contain the disease,regardless of the tumor stage and the extent of local disease at initial diagnosis.

Gradient inflammation in the pancreatic stump after pancreaticoduodenectomy:Two case reports and review of literature

BACKGROUND Postoperative pancreatic fistula(POPF)contributes significantly to morbidity and mortality after pancreaticoduodenectomy(PD).However,the underlying mechanisms remain unclear.This study explored this pathology in the pancreatic stumps and elucidated the mechanisms of POPF following PD.CASE SUMMARY Pathological analysis and 16S rRNA gene sequencing were performed on specimens obtained from two patients who underwent complete pancreatectomy for grade C POPF after PD.Gradient inflammation is present in the pancreatic stump.The apoptosis was lower than that in the normal pancreas.Moreover,neu-trophildominated inflammatory cells are concentrated in the ductal system.No-tably,neutrophils migrated through the ductal wall in acinar duct metaplasia-formed ducts.Additionally,evidence indicates that gut microbes migrate from the digestive tract.Gradient inflammation occurs in pancreatic stumps after PD.CONCLUSION The mechanisms underlying POPF include high biochemical activity in the pancreas,mechanical injury,and digestive reflux.To prevent POPF and address pancreatic inflammation and reflux,breaking the link with anastomotic dehi-scence is practical.

Translocation of a fish spike from the pharynx to the thyroid gland:A case report

BACKGROUND A fish spike stuck in the throat is a common ear,nose,and throat(ENT)emergency.However,it is very rare for a fish spike to reach the thyroid tissue through the throat,which is very dangerous and can lead to pharyngeal fistula,cervical abscess,mediastinal abscess,and thyroid abscess.Proper and timely management can help reduce complications,especially in elderly patients.CASE SUMMARY In the case presented here,the causative factor was dentures,but improper management aggravated the condition.In the case presented here,an elderly woman with a history of accidentally swallowing fish bones for 20 d had a sensation of foreign bodies in her throat.Eventually,computed tomography(CT)of the neck showed that the left side of the thyroid gland had a dense shadow in the form of a stripe.CONCLUSION If a fishbone foreign body is not visible during endoscopic examination but the patient has significant symptoms,the surgeon should be aware that the fishbone may be lodged in the thyroid.To avoid a misdiagnosis,ultrasound,CT,and other tests can be used to clarify the diagnosis.T The first step in treating a fish bone in the thyroid gland is to determine the position of the foreign body and the extent of the infection,and to develop a personalized surgical plan for its removal.At the same time,scientific information should be made available to the general public so that people know that if a fish bone is accidentally lodged,they should not force it to be swallowed or be spit out by inducing vomiting,which are incorrect methods and may aggravate the condition or even cause it to migrate outside the cavity,leading to serious complications,as in this reported case.

Appendiceal intussusception complicated by adenocarcinoma of the cecum:A case report

BACKGROUND Appendiceal intussusception is a pathological condition in which the appendix is inverted into the cecum,which may cause symptoms that resemble those of other gastrointestinal disorders and may induce intestinal obstruction.The rarity of this case presentation is the co-occurrence of appendiceal intussusception and cecal adenocarcinoma,a combination that to our knowledge has not previously been reported in the medical literature.This case provides new insights into the complexities of diagnosing and managing overlapping pathologies.CASE SUMMARY A 25-year-old woman presented with persistent periumbilical pain and bloody stools.An initial biopsy showed cecal cancer;however,subsequent colonoscopy and computed tomography findings raised the suspicion of appendiceal intussus-ception,which was later confirmed postoperatively.This unique case was charac-terized by a combination of intussusception and adenocarcinoma of the cecum.The intervention included a laparoscopic right hemicolectomy,which led to the histopathological diagnosis of mucinous adenocarcinoma with appendiceal intussusception.The patient recovered well postoperatively and was advised to initiate adjuvant chemotherapy.This case highlights not only the importance of considering appendiceal intussusception in the differential diagnosis,but also the possibility of appendicitis and the atypical presentation of neoplastic lesions.CONCLUSIONS Physicians should consider the possibility of appendiceal intussusception in cases of atypical appendicitis,particularly when associated with neoplastic presentation.

Pathologically successful conversion hepatectomy for advanced giant hepatocellular carcinoma after multidisciplinary therapy:A case report and review of literature

BACKGROUND Hepatocellular carcinoma(HCC)is one of the leading causes of death due to its complexity,heterogeneity,rapid metastasis and easy recurrence after surgical resection.We demonstrated that combination therapy with transcatheter arterial chemoembolization(TACE),hepatic arterial infusion chemotherapy(HAIC),Epclusa,Lenvatinib and Sintilimab is useful for patients with advanced HCC.CASE SUMMARY A 69-year-old man who was infected with hepatitis C virus(HCV)30 years previously was admitted to the hospital with abdominal pain.Enhanced computed tomography(CT)revealed a low-density mass in the right lobe of the liver,with a volume of 12.9 cm×9.4 cm×15 cm,and the mass exhibited a“fast-in/fast-out”pattern,with extensive filling defect areas in the right branch of the portal vein and an alpha-fetoprotein level as high as 657 ng/mL.Therefore,he was judged to have advanced HCC.During treatment,the patient received three months of Epclusa,three TACE treatments,two HAIC treatments,three courses of sintilimab,and twenty-one months of lenvatinib.In the third month of treatment,the patient developed severe side effects and had to stop immunotherapy,and the Lenvatinib dose had to be halved.Postoperative pathological diagnosis indicated a complete response.The patient recovered well after the operation,and no tumor recurrence was found.CONCLUSION Multidisciplinary conversion therapy for advanced enormous HCC caused by HCV infection has a significant effect.Individualized drug adjustments should be made during any treatment according to the patient's tolerance to treatment.

Successful management of severe hypoglycemia induced by total parenteral nutrition in patients with hepatocellular injury: Three cases reports

BACKGROUND Glucose imbalance is common in total parenteral nutrition(TPN).Hypoglycemia seems to be less frequent than hyperglycemia,but it influences the clinical outcome to a greater extent.Therefore,it should be effectively prevented and treated.However,there is no relevant report on how to treat hypoglycemia caused by TPN in patients with liver cell injury.CASE SUMMARY We present three patients with liver cell injury who developed severe hypo-glycemia during or after TPN infusion.The causes of severe hypoglycemia and glucose-raising strategies were discussed.According to the physiological charac-teristics of the hepatocellular injury,the ratio of nutrition components prescribed in TPN was appropriately adjusted for the three cases.We simultaneously reduced the dose of insulin and fat emulsion,and increased the dose of glucose in TPN.The blood glucose level was restored to normal range and clinical symptoms were eliminated.CONCLUSION When hypoglycemia occurs during or after TPN in patients with hepatocellular injury,physicians need to simultaneously reduce insulin and fat emulsion,and increase glucose,and correct severe hypoglycemia in time to reduce its adverse consequences.

Double casing warhead with sandwiched charge:The axial distribution of fragments velocities

The double casing warhead with sandwiched charge is a novel fragmentation warhead that can produce two groups of fragments with different velocity,and the previous work has presented a calculation formula to determine the maximum fragment velocity.The current work builds on the published formula to further develop a formula for calculating the axial distribution characteristics of the fragment velocity.For this type of warhead,the simulation of the dispersion characteristics of the detonation products at different positions shows that the detonation products at the ends have a much larger axial velocity than those in the middle,and the detonation products have a greater axial dispersion velocity when they are closer to the central axis.The loading process and the fragment velocity vary with the axial position for both casing layers,and the total velocity of the fragments is the vector sum of the radial velocity and the axial velocity.At the same axial position,the acceleration time of the inner casing is greater than that of the outer casing.For the same casing,the fragments generated at the ends have a longer acceleration time than the fragments from the middle.The proposed formula is validated with the X-ray radiography results of the four warheads previously tested experimentally and the 3D smoothedparticle hydrodynamics numerical simulation results of several series of new warheads with different configurations.The formula can accurately and reliably calculate the fragment velocity when the lengthto-diameter ratio of the charge is greater than 1.5 and the thickness of the casing is less than 20%its inner radius.This work thus provides a key reference for the theoretical analysis and the design of warheads with multiple casings.

Reconstruction of cervical necrotizing fasciitis defect with the modified keystone flap technique:Two case reports

BACKGROUND Cervical necrotizing fasciitis(CNF)is a rare,aggressive form of deep neck space infection with significant morbidity and mortality rates.Serial surgical debridement acts as the cornerstone of CNF treatment;however,it often results in defects requiring complex reconstructions.CASE SUMMARY We report two cases in which the keystone flap(KF)was used for CNF defect coverage:Case 1,an 85-year-old patient with CNF in the anterior neck,and Case 2,a 54-year-old patient with CNF in the posterior neck.Both patients received empirical intravenous antibiotic therapy and underwent serial debridement,enabling adequate wound preparation and stabilization.The final defect size measured 5.5 cm×12 cm in Case 1 and 6 cm×11 cm in Case 2.For defect coverage,we employed an 8 cm×19 cm type II KF based on perforators from the superior thyroid artery in Case 1 and a 9 cm×18 cm type II KF based on perforators from the transverse cervical artery in Case 2.Both flaps showed complete survival.No postoperative complications occurred in both cases,and favorable outcomes were observed at 7-and 6-month follow-ups in case 1 and 2,respectively.CONCLUSION We effectively treated CNF-associated defects using the KF technique;KF is viable for covering CNF defects in carefully selected cases.

Changes in macrophage infiltration and podocyte injury in lupus nephritis patients with repeated renal biopsy: Report of three cases

BACKGROUND In this study,we retrospectively analysed macrophage infiltration and podocyte injury in three patients with diffuse proliferative lupus nephritis(LN)who un-derwent repeated renal biopsy.CASE SUMMARY Clinical data of three diffuse proliferative LN patients with different pathological characteristics(case 1 was LN IV-G(A),case 2 was LN IV-G(A)+V,and case 3 was LN IV-G(A)+thrombotic microangiopathy)were reviewed.All patients underwent repeated renal biopsies 6 mo later,and renal biopsy specimens were studied.Macrophage infiltration was assessed by CD68 expression detected by immunohistochemical staining,and an immunofluorescence assay was used to detect podocin expression to assess podocyte damage.After treatment,Case 1 changed to LN III-(A),Case 2 remained as type V LN lesions,and Case 3,which changed to LN IV-S(A),had the worst prognosis.We observed reduced macro-phage infiltration after therapy.However,two of the patients with active lesions after treatment still showed macrophage infiltration in the renal interstitium.Before treatment,the three patients showed discontinuous expression of podocin.Notably,the integrity of podocin was restored after treatment in Case 1.CONCLUSION It may be possible to reverse podocyte damage and decrease the infiltrating ma-crophages in LN patients through effective treatment.

Paradoxical herniation associated with hyperbaric oxygen therapy after decompressive craniectomy: A case report

BACKGROUND Whether hyperbaric oxygen therapy(HBOT)can cause paradoxical herniation is still unclear.CASE SUMMARY A 65-year-old patient who was comatose due to brain trauma underwent decompressive craniotomy and gradually regained consciousness after surgery.HBOT was administered 22 d after surgery due to speech impairment.Paradoxical herniation appeared on the second day after treatment,and the patient’s condition worsened after receiving mannitol treatment at the rehabilitation hospital.After timely skull repair,the paradoxical herniation was resolved,and the patient regained consciousness and had a good recovery as observed at the follow-up visit.CONCLUSION Paradoxical herniation is rare and may be caused by HBOT.However,the underlying mechanism is unknown,and the understanding of this phenomenon is insufficient.The use of mannitol may worsen this condition.Timely skull repair can treat paradoxical herniation and prevent serious complications.

Evaluation of the injection and plugging ability of a novel epoxy resin in cement cracks

Sustained casing pressure(SCP)is a crucial issue in the oil and gas production lifecycle.Epoxy resins,exhibiting exceptional compressive strength,ductility,and shear bonding strength,have the potential to form reliable barriers.The injectivity and sealing capacity of the epoxy resin is crucial parameters for the success of shallow remediation operations.This study aimed to develop and assess a novel solid-free resin sealant as an alternative to Portland cement for mitigating fluid leakage.The investigation evaluated the viscosity,compressive strength,and brittleness index of the epoxy resin sealant,as well as its tangential and normal shear strengths in conjunction with casing steel.The flow characteristics and sealing abilities of conventional cement and epoxy resin were comparatively analyzed in cracks.The results showed that the application of a viscosity reducer facilitated control over the curing time of the epoxy resin,ranging from 1.5 to 6 h,and reduced the initial viscosity from 865.53 to 118.71 m Pa,s.The mechanical properties of the epoxy resin initially increased with a rise in curing agent content before experiencing a minor decrease.The epoxy resin containing 30%curing agent exhibited optimal mechanical properties.After a 14-day curing period,the epoxy resin's compressive strength reached81.37 MPa,2.12 times higher than that of cement,whereas the elastic modulus of cement was 2.99 times greater than that of the epoxy resin.The brittleness index of epoxy resin is only 3.42,demonstrating high flexibility and toughness.The tangential and normal shear strengths of the epoxy resin exceeded those of cement by 3.17 and 2.82 times,respectively.In a 0.5 mm-wide crack,the injection pressure of the epoxy resin remained below 0.075 MPa,indicating superior injection and flow capabilities.Conversely,the injection pressure of cement surged dramatically to 2.61 MPa within 5 min.The breakthrough pressure of0.5 PV epoxy resin reached 7.53 MPa,decreasing the crack's permeability to 0.02 D,a mere 9.49%of the permeability observed following cement plugging.Upon sealing a 2 mm-wide crack using epoxy resin,the maximum breakthrough pressure attained 5.47 MPa,3.48 times of cement.These results suggest that epoxy resin sealant can be employed safely and effectively to seal cracks in the cement.