Case studies of up-cycling of partially crystallized ceramic waste in highly porous glass-ceramics

Highly porous glass-based materials represent a solution for thermal insulation. However, the manufacturing costs still affect their extensive use. The present investigation proposes savings in the production of foams by use of discarded materials, such as polishing residue or vitrified asbestos-containing waste, minimizing additives and processing temperatures. Aqueous suspensions of powders, mixed with soda-lime glass, underwent progressive gelation due to alkali activation. An extensive foaming was determined by mechanical stirring, with the help of a surfactant. Finally, a firing step yielded foams exhibiting excellent strength-to-density ratios, due to densification and control of crystal phases, both supported by the glass addition

Multilayer GZ/YSZ thermal barrier coating from suspension and solution precursor plasma spray

Gas turbines rely on thermal barrier coating (TBC) to thermally insulate the nickel-based superalloys underneath during operation; however, current TBCs, yttria stabilised zirconia (YSZ), limit the operating temperature and hence efficiency. At an operating temperature above 1200 °C, YSZ is susceptible to failure due to phase instability and CMAS (Calcia-Magnesia-Alumina-Silica) attack. Gadolinium zirconates (GZ) could overcome the drawback of YSZ, complementing each other with the multi-layer approach. This study introduces a novel approach utilising axial suspension plasma spray (ASPS) and axial solution precursor plasma spray (ASPPS) to produce a double-layer and a triple-layer TBCs with improved CMAS resistance. The former comprised suspension plasma sprayed GZ and YSZ layers while the latter had an additional dense layer deposited through a solution precursor to minimise the columnar gaps that pre-existed in the SPS GZ layer, thus resisting CMAS infiltration. Both coatings performed similarly in furnace cycling test (FCT) and burner rig testing (BRT). In the CMAS test, the triple-layer coating exhibited better CMAS reactivity, as evidenced by the limited CMAS infiltration observed on the surface

FMECA and FTA analysis applied to the manufacturing process of pulsating heat pipes

Pulsating heat pipes (PHPs) offer significant advantages for the thermal control of electronic components due to their simple manufacturing and high heat transfer rates. The reliability of PHPs has traditionally been assessed through long-life testing, but detailed reliability analyses from an equipment perspective are limited. The study of PHP reliability is essential due to its application and operational conditions. For instance, in aerospace applications these devices operate under severe conditions, and maintenance or replacement is impossible during operation, making them critical components in system functionality. The reliability analysis of PHPs focuses on the manufacturing process, considering future operating conditions. Although preliminary PHP testing will be conducted on Earth, laboratory conditions are less stringent due to the difficulty of replicating launch acceleration and space conditions for long-term testing under microgravity. This study presents an FMECA (Failure Modes, Effects, and Criticality Analysis) of the pulsating heat pipe manufacturing process, breaking down the production of each component. The results indicate that the most critical point is concentrated in the assembly of these components, leading to a higher incidence of welding failures. It recommends further work to improve welding and analyze mechanical stresses within the heat pipe

Adrenalectomía laparoscópica por metástasis metácrona. Experiencia en 12 casos

To assess the peroperative and oncological results of laparoscopic adrenalectomy for an isolated metastasis. MATERIAL AND METHODS: A retrospective, descriptive study was conducted of 12 laparoscopic adrenalectomies performed for metastases out of a total of 40 adrenalectomies performed from May 1998 to April 2009. The primary tumor was pulmonary in 7 patients, renal in 3, and colonic in 2. Demographic data collected included median age, operating time, blood loss, complications, tumor size, and length of hospital stay. The Kaplan-Meier method was used to analyze survival. RESULTS: Operating time was 150 min (range, 90-206). Peroperative bleeding was 60 ml (range, 15-150). Peroperative complications occurred in 3% of patients. Tumor size was 4.5 cm (range, 1.3-8.5). No positive margins were seen in the resected specimens. Hospital stay was 3 days (range 3-5). Actuarial survival was 55.6% at 23 months (range, 2-38) with mean and median follow-up times of 20.9 and 23 months. CONCLUSIONS: In selected patients, laparoscopic adrenalectomy for metastasis is a safe procedure with oncological results superimposable to those of open surgery

Nefrectomía parcial laparoscópica. Análisis de los primeros 30 casos de nuestra serie y revisión de la literatura

Objective: Our goal is to analyze the surgical and clinicopathological results of our first 30 laparoscopic partial nephrectomies (LPN) performed consecutively and correlate the results with the literature. Material and methods: This is a cases series, with 30 patients (20 men and 10 women) operated between 2006 and 2008. We assessed the clinicopathological factors and complications. The mean and median follow-up was 25 and 5 months. Results: Resected tumors had an average size of 2.4 cm. 60% of the tumors were malignant. The pathological stage was pT1 in 100% of cases (47% grade I, 53% Fuhrman grade II). Surgical margins were positive in 3 cases, switching to open surgery. Intraoperative bleeding was 74.66 cc (35.7±SD) and 70 cc of mean and median. The mean operative time was 214.4min (±69) and ischemia time of 31.3min (±13.8). Conclusions: Our results are similar to those reported in the literature, except for positive margins and conversion attributable to the learning curve

In-vitro cell interaction and apatite forming ability in simulated body fluid of ICIE16 and 13-93 bioactive glass coatings deposited by an emerging suspension high velocity oxy fuel (SHVOF) thermal spray

ICIE16 and 13-93 bioactive glasses have been proposed as alternative chemically stable compositions in physiological fluid keeping bioactivity comparable to Bioglass®. ICIE16 and 13-93 bioactive glasses coatings were produced via an emerging suspension high-velocity oxy-fuel (SHVOF) thermal spraying technique. Suspensions of ICIE16 and 13-93 with 10 wt% solid loading in isopropanol (IPA) and water were used to produce coatings on AISI304 stainless steel using a flame power of 50 kW and 75 kW. For both glass formulations, the coatings deposited at a lower flame power were more porous, less hard, and less rough (~6% porous and 242 HV) than the coatings obtained at a higher flame power (~4% porosity and 300 HV). ICIE16 coatings showed more dissolution in SBF (simulated body fluid) than the 13-93 coatings. Moreover, the 13-93 glass coating sprayed at 75 kW showed the highest stability in SBF since only 2% of the coating was resorbed in SBF after 7 days of immersion and revealed apatite precipitation after 7 days. In-vitro cell tests, using MG63 cells, showed good cell attachment and proliferation on the surfaces of the coatings, revealing good cytocompatibility. The 13-93 coating sprayed at 75 kW revealed the highest cell proliferation after 7 days of incubation. This can be attributed to the higher surface roughness of the coating (Ra = 6.5 ± 0.6 μm)

Association of crossed renal ectopia and aortic aneurism. Case report

OBJECTIVE: Renal malformations are rare entities and rarely have clinical consequences. Crossed renal ectopia has an incidence of 1/2.000 autopsies. The association with aortic aneurysm is even more exceptional. METHODS: We present our case and perform a bibliographic review. RESULTS: To date and in our knowledge , seven cases of crossed renal ectopia associated with aortic aneurysm were described on the literature. This malformation makes the treatment of the aneurysm more complex. The possibility of renal function decrease caused by injuries to the renal arteries during the surgical procedure is always present. Because of this risk of injury of the kidney during surgery preoperative evaluation of the vascularization must include image technologies as the MRI, CT-angiography or conventional arteriography. During the aortic intervention vascular conservation must be performed and it is necessary to minimize the time of renal ischemia. CONCLUSIONS: The association of crossed renal ectopia and aortic aneurysm is a rare event. The surgical intervention of the aorta does not have to necessarily originate a loss of renal function. Anyway the worsening of the renal clearance must be foreseen

YAG thermal barrier coatings deposited by suspension and solution precursor thermal spray

Yttrium aluminium garnet (YAG) is a promising topcoat material for thermal barrier coatings due to its high temperature stability and better CMAS (calcium-magnesium-alumino-silicate) resistance. YAG topcoats were deposited by suspension and solution precursor high-velocity oxy-fuel (HVOF) thermal spray. The relationships between processing, microstructure and final properties were studied through a range of characterization techniques and thermal cycling tests. The microstructure of the as-sprayed YAG topcoat from stoichiometric solution precursor (SP-YAG) had distributed pores and inter-splat boundaries, while the as-sprayed topcoat produced from suspension (S-YAG) had vertical and branched micro cracks, pores, and inter-splat boundaries. Both as-sprayed coatings were composed of amorphous phase, hexagonal yttrium aluminium perovskite (YAP) and cubic YAG. In thermal cycling tests, 20% of SP-YAG failure was reached after the 10th cycle; whereas, S-YAG reached the failure criteria between the 60th and 70th cycle. The failure of both the SP-YAG and the S-YAG topcoats occurred due to thermal stresses during the thermal cycling

Respuesta y supervivencia libre de progresión en tumores vesicales en estadiosT2-T4 tratados con tratamiento trimodal de conservación vesical

Objective: Toevaluatetheresponseandthefree-survivalprogressioninpacientsdiagnosed of invasivebladdercancerwhohavebeentreatedwithtransurethralresection, chemotherapyandradiotherapy.Thismultimodaltreatmentiscomparedwithanot random serieofpatientstreatedbyradicalcistectomy. Material andmethods: Retrospectiveanalysisof43casesofinvasivebladdercancertreated with twoschemesofbladderpreservationbetween1994–2007.Theyarecomparedwith145 cases treatedwithradicalcistectomyinthesameperiodoftime. Pronosticvariablesincludedinthestudyareclinicalstage,gradeofdifferentiation, presence ofureteralobstruction,chemotherapymodality,radiotherapydosesandp53and ki-67 expression. Results: Meanandmediantimeare51and39monthsinpatientswithmultimodal treatment.Completeresponseisachievedin72%ofcasestreatedwithbladder preservation.Ureteralobstructionisaprognosticfactor(OR:7,3;p:0,02).72%patientswith complete responsemantainitattheendofthestudy.Noneofanalyzedvariablesare predictors ofmaintenanceoftheresponse. Survivalrateswithaintactbladderwere6977% and6177% atthreeandfiveyears. Radiotherapydosesgreaterthan60Gy(OR:6,1;po0,001) andtheabsenceofureteral obstruction (OR:7,5;po0,002) werepronosticvariables. Free-survivalinpatientswithcompleteresponsewas8077% and58710% atthreeand five years. At theendofthestudy,53,5%ofpatientshadaintactbladderandfree-disease. Inthesameperiodoftime,145radicalcistectomieswereperformedduetomuscleinvasive bladdercancer.Meanandmediantimeinthisgroupwere29and18monthsrespectively. Stadisticalanalysisrevealsaworseclinicalstageinthegroupofpatientstreatedwith multimodaltreatment(p:0.01). Free-survivalwas7275% and6377%at3and5yearsinthegroupofradical cistectomies.Therewasnotstadisticalsignificantdifferencesbetweencistectomiesand bladderpreservation. Conclusions: Patientstreatedwithbladderpreservationhaveafree-survivalsimilartothose tretedwithradicalcistectomy.Radiotherapy doses greaterthan60Gyandabsenceofureteral obstructionwerefree-survivalprognosticvariables

Factores influyentes en el tiempo hasta la progresión bioquímica después de prostatectomía radical

INTRODUCTION: We assessed the time-influencing clinical-pathological factors for biochemical progression of an equal series of patients from a single institution. MATERIALS AND METHODS: Retrospective analysis of 278 patients with biochemical progression following prostatectomy. We considered biochemical progression to be PSA>0.4 ng/ml. We performed the trial using the Cox model (univariate and multivariate) and using the Student's t-test to compare averages. RESULTS: With a mean follow-up of 4 (±3 DE) years, the univariate study showed a mean until progression for the Gleason score 2-6 in the biopsy of 824 days and 543 for the Gleason score 7-10 (p=0.003). For negative surgical margins, the mean was 920 days and 545 for positive margins (p=0.0001). In the case of a Gleason score 2-7 in the specimen, the mean was 806 days and 501 for a Gleason score 8-10 (p=0.001). Lastly, the mean for the cases with Ki-67 negative in the specimen ( 10%) (p=0.003). In the multivariate study, Ki-67 (OR 1.028; IC 95% 1-1.01; p=0.0001) and Gleason score 8-10 (OR 1.62; IC 95% 1.5-2.45; p=0.026) in the specimen, and initial PSA >10 ng/ml (OR 1.02; IC 95% 1.01-1.04; p=0.0001) were independent variables. Using these variables, we designed a predictive model with three groups. The time until the progression of each group was 1,081, 551 and 218 days respectively. CONCLUSION: The Gleason score 7-10 in the prostate biopsy, the presence of Ki-67, the positive margins and the Gleason score 8-10 in the specimen, and the initial PSA > 10 ng/ml are time-influencing factors until biochemical progression. Pathological Gleason score 8-10, PSA > 10 ng/ml and Ki-67 are independent factors