Refractory

In this study, optimization of some parameters of stirred mill on ultra-fine grinding of refractory Au/Ag ores was performed. A three-level Box-Behnken design combining a response surface methodology (RSM) with quadratic programming (QP) was employed for modelling and optimization of some operating parameters in ultra-fine grinding. Grinding tests were carried out in a laboratory scale pin-type vertical stirred mill. The relationship between the response, i.e. d 80 size, and four grinding parameters, i.e. ball diameter, grinding time, ball charge ratio and stirrer revolution was presented as empirical model equations. Analysis of variance showed a high coefficient of determination value (R 2 = 0.9698), thus ensuring a satisfactory of the second-order regression model with the experimental data. The model equations were then optimized using the quadratic programming method to minimize for d 80 size within the experimental range studied. The optimum conditions were found to be 1.61 mm for ball diameter, 11.50 min for grinding time, 80% for ball charge ratio and 745 rpm for stirrer revolution for this grinding process. In order to verify the improvement of grinding performance using the optimal level of control factors three verification experiments were conducted, and the results for d 80 was 3.37 μm, which were smaller than those obtained in the initial tests.

In this study, optimization of some parameters of stirred mill on ultra-fine grinding of refractory Au/Ag ores was performed. A three-level Box-Behnken design combining a response surface methodology (RSM) with quadratic programming (QP) was employed for modelling and optimization of some operating parameters in ultra-fine grinding. Grinding tests were carried out in a laboratory scale pin-type vertical stirred mill. The relationship between the response, i.e. d 80 size, and four grinding parameters, i.e. ball diameter, grinding time, ball charge ratio and stirrer revolution was presented as empirical model equations. Analysis of variance showed a high coefficient of determination value (R 2 = 0.9698), thus ensuring a satisfactory of the second-order regression model with the experimental data. The model equations were then optimized using the quadratic programming method to minimize for d 80 size within the experimental range studied. The optimum conditions were found to be 1.61 mm for ball diameter, 11.50 min for grinding time, 80% for ball charge ratio and 745 rpm for stirrer revolution for this grinding process. In order to verify the improvement of grinding performance using the optimal level of control factors three verification experiments were conducted, and the results for d 80 was 3.37 μm, which were smaller than those obtained in the initial tests.

A study on castables refractories used in Blast Furnaces runners is presented. The objective is to increase the knowledge on the behavior of this type of materials. This study includes a characterization of the refractory material, both before and after use. The analysis of the sintering reaction, the study on silicon carbide dissociation and the thermodynamical interpretation on the SiC-CO system, jointly with the post mortem study results permitted to identify the carbon oxidation mechanisms of the several runner zones. Finally, the equilibrium phase diagram analysis and thermal profile diagram of the blast furnace runner let us to establish key factors on castable refractory wear in service.

The productivity of high speed milling operations is limited by the onset of self-excited vibrations known as chatter. Unless avoided, chatter vibrations may cause large dynamic loads damaging the machine spindle, cutting tool, or workpiece and leave behind a poor surface finish. The cutting force magnitude is proportional to the thickness of the chip removed from the workpiece. Many researchers focused on the development of analytical and numerical methods for the prediction of chatter. However, the applicability of these methods in industrial conditions is limited, since they require accurate modelling of machining system dynamics and of cutting forces. In this study, chatter prediction was investigated for orthogonal cutting in turning operations. Therefore, the linear analysis of the single degree of freedom (SDOF) model was performed by applying oriented transfer function (OTF) and \tau decomposition form to Nyquist criteria. Machine chatter frequency predictions obtained from both forms were compared with modal analysis and cutting tests.

Background: Paradoxically, some reports in the literature support the use of antipsychotics in the treatment of Obsessive Compulsive Disorder (OCD), while other reports suggest that antipsychotics can exacerbate OCD symptoms. To date, there is no published systematic review of the relationship between OCD symptoms and antipsychotic drugs. Methods: A Medline and PsychInfo search (1980 -2003) was conducted to collect published reports of the interactions between antipsychotics and OCD symptoms. Results: In the treatment of refractory OCD, case series, open label trials and placebo-controlled trials were found suggesting efficacy of antipsychotic augmentation to ongoing antidepressant treatment. In the placebo-controlled trials with haloperidol, risperidone, olanzapine, and quetiapine, a significantly higher response rate (46 -71%) was found for the antipsychotic groups, compared to no response for the placebo groups. Reports of exacerbation of OCD symptoms with the use of atypical antipsychotics were limited to individuals with a primary psychotic disorder. Limitations: Definition of response in most of these treatment studies was based on a modest reduction of OCD symptoms, and no studies were available on long-term efficacy. There were also no published reports that systematically evaluated the incidence of OCD symptoms associated with atypical antipsychotics. Conclusions: All antipsychotics mentioned above had short-term controlled evidence to support their use as augmenting agents in the treatment of refractory OCD. The suggested management of OCD induction/exacerbation due to atypical antipsychotics is to increase the dose of the atypical antipsychotic and/or add a selective serotonin reuptake inhibitor. D

To evaluate the pattern of prescription of antiepileptic drugs (AEDs) and other medications in a representative population of patients with refractory epilepsy attending tertiary referral centres in Italy.Descriptive analysis of data obtained at baseline from 933 adults and 191 children with refractory epilepsy enrolled consecutively in an observational study at 11 tertiary referral centres in Italy. Multivariate logistic regression analysis was used to assess predictors of utilization of the most commonly prescribed AEDs.Polytherapy was used in 79% of adults and 75% of children, with over one-third of adults and children being prescribed ≥3 AEDs. In adults, the most commonly used AEDs were levetiracetam (35%), carbamazepine (34%) and lamotrigine (30%). In children, valproic acid was by far the most commonly used AED (46%), followed by carbamazepine (27%), topiramate (21%), and phenobarbital (20%). The most common AED in partial epilepsy was carbamazepine (331 out of 893 patients, 37%), followed by levetiracetam (33%) and lamotrigine (26%). In generalized or undetermined epilepsies, the AEDs most commonly used were valproic acid (139 out of 223 patients, 62%), lamotrigine (33%) and levetiracetam (28%). Second generation AEDs were prescribed in 81% of adults and 54% of children. Comedications used for indications other than epilepsy were used by 32% of adults and 17% of children.Prescription patterns were consistent with current evidence about the spectrum of efficacy of individual AEDs in different epilepsy syndromes. The high prevalence of polytherapy, including combinations of three or more AEDs, is a cause for concern.

MgAl2O4 (MA) spinel powder was synthesized by heating an equimolar composition of MgO and Al2O3 in LiCl, KCl, or NaCl. The synthesis temperature can be decreased from >1300°C (required by the conventional solid–solid reaction process) to ∼1100°C in LiCl, or to ∼1150°C in KCl or NaCl. The molten salt synthesized MA powder was pseudomorphic and retained, to a large extent, the size and morphology of the original Al2O3 raw material, indicating that a “template formation mechanism” plays an important role in the synthesis process.

Municipal solid waste incineration (MSWI) bottom ash contains a considerable amount of heavy metals. The occurrence and uneven distribution of these heavy metals in bottom ash can increase the complexity of such residues in terms of long-term behavior upon landfilling or recycling. Bottom ashes sampled from three stoker-type incinerators in Japan were analyzed in this paper. This study presents detailed information on the mineralogical characterization of bottom ash constituents and the weathering behavior of these constituents by means of optical microscopy and scanning electron microscopy. It was revealed that bottom ash mainly consists of assorted silicate-based glass phases (48-54 wt% of ash) and mineral phases including melilites, pseudowollastonite, spinels, and metallic inclusions (Fe-P, Fe-S, Fe-Cu, Cu-Sn, Cu-Zn, Cu-S, and Cu-Pb dominated phases), as melt products formed during the incineration process. The compounds embedded in the glass matrix, e.g. spinels and metallic inclusions, played the most important role in concentration of heavy metals (Pb, Zn, Cu, Cr, Mn, Ni, etc.). Other phases such as refractory minerals and ceramics, frequently found in ash, were of less significance in terms of their influence on the involvement of heavy metals. Analysis of lab-scale artificially weathered and 10-year landfilled bottom ash samples revealed that secondary mineralization/alteration of the bottom ash constituents principally carbonation and glass evolution substantially decreased the potential risk of the heavy metals to the surrounding environment.

Mechanical properties of slip-cast alumina -mullite (AM) refractories were improved significantly by the addition of f 2-Am zircon (ZrSiO 4 ) particles. Fracture behaviour showed mainly transgranular, with some intergranular, fracture. R parameter showed that there was a marked incline in resistance to fracture initiation. Thermal shock tests confirmed that the retained strength and Young's modulus of alumina -mullite -zircon refractories were improved by increasing the quench temperature, indicating higher resistance to crack propagation. D

Objective: To assess an uncontrolled, open-label trial of sleep-disordered breathing (SDB) treatment on two different samples of chronic insomnia patients. Method: In Study 1 (Retrospective), data from one diagnostic and one continuous positive airway pressure (CPAP) titration polysomnogram were compiled from 19 chronic insomnia patients with SDB. Objective polysomnogram indicators of sleep and arousal activity and self-reported sleep quality were measured. In Study 2 (Prospective), clinical outcomes were assessed after sequential cognitive-behavioral therapy (CBT) and SDB therapy (CPAP, oral appliances, or bilateral turbinectomy) were provided to 17 chronic insomnia patients with SDB. Repeat measures included the Insomnia Severity Index, Functional Outcomes of Sleep Questionnaire, Pittsburgh Sleep Quality Index, and self-reported insomnia indices and CPAP use. Results: In Study 1, seven objective measures of sleep and arousal demonstrated or approached significant improvement during one night of CPAP titration. Sixteen of 19 patients reported improvement in sleep quality. In Study 2, Insomnia Severity Index, Functional Outcomes of Sleep Questionnaire, and Pittsburgh Sleep Quality Index improved markedly with CBT followed by SDB treatment and achieved an average outcome equivalent to curative status. Improvements were large for each treatment phase; however, of 17 patients, only 8 attained a nonclinical level of insomnia after CBT compared with 15 patients after SDB therapy was added. Self-reported insomnia indices also improved markedly, and self-reported SDB therapy compliance was high. Conclusions: In one small sample of chronic insomnia patients with SDB, objective measures of insomnia, arousal, and sleep improved during one night of CPAP titration. In a second small sample, validated measures of insomnia, sleep quality, and sleep impairment demonstrated clinical cures or near-cures after combined CBT and SDB therapies. These pilot results suggest a potential value in researching the pathophysiological relationships between SDB and chronic insomnia, which may be particularly relevant to patients with refractory insomnia.

Mechanical properties of slip-cast alumina -mullite (AM) refractories were improved significantly by the addition of f 2-Am zircon (ZrSiO 4 ) particles. Fracture behaviour showed mainly transgranular, with some intergranular, fracture. R parameter showed that there was a marked incline in resistance to fracture initiation. Thermal shock tests confirmed that the retained strength and Young's modulus of alumina -mullite -zircon refractories were improved by increasing the quench temperature, indicating higher resistance to crack propagation. D

There is no standard salvage regimen for AML. We retrospectively compared two commonly used regimens at our institution: CLAG and MEC. The complete response rate (CR) was 37.9% for CLAG (n = 97) and 23.8% for MEC (n = 65) (P = 0.048), with median overall survival (OS) of 7.3 and 4.5 months, respectively (P = 0.05). In primary refractory disease, CR was 45.5% for CLAG and 22.2% for MEC (P = 0.09), with median OS of 11 and 4.5 months, respectively (P = 0.07). In first relapse, CR was 36.8% and 25.9% (P = 0.35) and median OS was 6.7 and 6.7 months, respectively (P = 0.87). Our data support use of CLAG for RR-AML.

A 36-year-old female with metastatic breast cancer involving bones, liver, lung, and pleura/chest wall with worsening back pain received weight-based intravenous (IV) ketamine and was transitioned to oral ketamine for cancer-related neuropathic pain. She had responded poorly to outpatient pain regimen of oxycodone sustained and immediate release, hydromorphone, gabapentin, and duloxetine (approximate 480 mg total oral morphine equivalents [OME]), reporting an initial pain score of 10/10. She was started on hydromorphone parenteral patient-controlled analgesia (PCA) bolus dose in addition to her outpatient regimen. Despite escalating doses of opioids and the addition of a lidocaine 5% patch, the patient's pain remained uncontrolled 6 days after admission. On hospital day 7, utilizing a hospital weight-based ketamine protocol, the patient was started on subanesthetic doses of ketamine at 0.2 mg/kg/h (288 mg/24 h) and titrated over 2 days to 0.4 mg/kg/h (576 mg/24 h). Then, a 3-day rotation from intravenous to oral ketamine was initiated, and the patient was discharged on ketamine oral solution, 75 mg every 8 hours. When the patient's dose was increased to 0.4 mg/kg/h, adequate pain relief was charted by the nurse within 120 minutes, "patient pain free and resting comfortably." Her pain continued to be well managed, with an average pain score of 5/10 with the ketamine continuous infusion and sustained with conversion to oral ketamine without any report of side effects. This was a 37% reduction in pain scores. With the patient's stabilized dose of ketamine, opioid requirements decreased by 61.4% (1017.5 mg reduction in total OME). The use of weight-based dosing of IV continuous infusion and transition to oral ketamine was effective and tolerable in the management of opioid-refractory, neuropathic cancer pain. It is hoped that this case report promotes a discussion regarding ketamine dosing in refractory neuropathic cancer pain.

We report the efficacy of the ketogenic diet in refractory epilepsies focusing on outcomes with regard to epilepsy syndromes and etiology in children and adults with refractory epilepsy. Sixty-four consecutive children and four adults were prospectively enrolled from 2002 to 2009; seven were excluded from analysis. The classical ketogenic diet was initiated on an inpatient basis with dietary ratios ranging from 2:1 to 4:1 fat to carbohydrate and protein. Patients were classified according to syndrome and etiology using the 1989 and more recent 2010 International League Against Epilepsy (ILAE) classification systems. Responders were defined as >50% reduction in seizure frequency compared to baseline. Syndromes included symptomatic generalized (52), genetic (idiopathic) generalized , and focal epilepsies (2) and etiologies included structural (24), genetic (18), and unknown . Twenty-nine (48%) of 61 patients were responders at 3 months. Two children became seizure-free: one with focal epilepsy of unknown etiology and another with refractory childhood absence epilepsy. Responsive syndromes included migrating partial epilepsy of infancy, childhood absence epilepsy, focal epilepsy, epilepsy with myoclonic-atonic seizures, and Dravet syndrome. Children with lissencephaly and hypoxic ischemic encephalopathy had surprisingly good responses. The ketogenic diet is an effective treatment for children and adults with refractory epilepsy. The response is predicted by type of epilepsy syndrome. Accurate characterization of the electroclinical syndrome is an important factor in decisions about timing of initiation of the ketogenic diet.

Indole is a typical refractory and inhibitory compound present in coking wastewater. The aim of this study was to investigate possible electricity generation with indole degradation in the microbial fuel cell (MFC). Experiments were conducted in two types of the MFC: a continuous-fed MFC (C-MFC) and a batch-fed MFC (B-MFC). In the C-MFC, the maximum power densities reached 45.4, 51.2, and 2.1 W/m 3 , respectively, from using 1000 mg/L glucose, a mixture of 1000 mg/L glucose and 250 mg/L indole, and 250 mg/L indole as the fuel. When using 250 mg/L indole as the fuel, the removal efficiency of indole was up to 88% within 3 h. Increasing indole concentrations from 250 to 1500 mg/L resulted in decrease of the maximum power densities from 2.1 to 0.8 W/m 3 , and average degradation rates from 41.7 to 8.9 mg/(L h). Compared with the C-MFC, the B-MFC increased the maximum power densities from 2.1 to 3.3 W/m 3 and the coulombic efficiencies from 0.7% to 81.5%. Microbial community analyses showed that the addition of indole obviously changes the microbial community of the anode electrode, including the changes of relative abundance and emergence of new species. The results should be useful for treatment of wastewater containing indole.

Mineral phases of three metallurgical cokes were characterized after reactions with CO 2 at 1373 and 1773 K in a horizontal furnace for 2 h using X-ray diffraction (XRD) and scanning electron microscope/energy dispersive spectroscopy (SEM/EDS). After reaction at 1373 K, all cokes displayed an increased degree of mineral decomposition, dissemination within the carbon matrix, and inclusions in pores such that the intensity of transformation varied with coke types. As for the original cokes, XRD analysis of the reacted cokes indicated the presence of quartz, mullite, and high melting point aluminosilicate as the major refractory phases while pyrrhotite, triolite, iron oxides, and metallic iron phases were the main reactive phases. Framboidal sulfide appeared to diminish after CO 2 reactions. Iron-spinel was the common reaction product while olivine was observed in only one coke. All minerals occurred in a wide variety of sizes and distributions such that fine minerals occurred mainly within or close to pores and were comprised of iron sulfide and Al 2 O 3 . At 1773 K, aggregates of Al-silicates decomposed further to form mullite and cristobalite while low melting point Alsilicates transformed to running slag in coke. Iron was observed to occur in many forms including metallic iron, silicates, and oxides but less frequently as sulfides and appeared to occur within or in close proximity to pores. At 1773 K, pore inclusions were the prominent features of the reacted cokes, particularly a high proportion of Al 2 O 3 (corundum). Calcium was observed as silicates as well as thermally stable phosphate and sulfides. This study demonstrated that characteristics of coke minerals after reactions at standard coke strength after reaction (CSR) test temperatures of 1373 and 1773 K were significantly different in terms of phase distribution which would influence coke strength and reactivity accordingly. This study implies that coke properties measured at relatively lower temperatures in the conventional tests may not provide a true assessment of coke performance in an operating blast furnace. Steiler, J. M.; Beppler, E.; Jahusen, U.; Bennington; Willmers, R. R. Assessment of coke degradation in the blast furnace from tuyeres probing investigations.

Advanced oxidation processes (AOPs) such as Fenton, electro-Fenton and photo-Fenton have been applied effectively to remove refractory organics from landfill leachate. The Fenton reaction is based on the addition of hydrogen peroxide to the wastewater or leachate in the presence of ferrous salt as a catalyst. The use of this technique has proved to be one of the best compromises for landfill leachate treatment because of its environmental and economical advantages. Fenton process has been used successfully to mineralize wide range of organic constituents present in landfill leachate particularly those recalcitrant to biological degradation. The present study reviews the use of Fenton and related processes in terms of their increased application to landfill leachate. The effects of various operating parameters and their optimum ranges for maximum COD and color removal are reviewed with the conclusion that the Fenton and related processes are effective and competitive with other techn...

Tannery wastewater contains high concentrations of organic matter (COD) with a significant percentage of refractory organic compounds, ammonium substances, salts (i.e. chloride and sulphate) as well as sulphur. Contaminants have to be removed in order to avoid significant environmental impacts. This paper presents the results obtained from a pilot scale study developed in the tannery district of Solofra in Southern Italy. It was aimed at evaluating the reuse of wastewater produced in the retanning process. The treatment process consisted of a biological treatment, as a pre-treatment, followed by a physico-chemical process (with a polymer as a coagulant) and reverse osmosis with a plane membrane. The biological pre-treatment was able to remove approx. 67% of COD, while the membrane system completed the purification process with the removal of the refractory organic compounds (chloride and sulphate). In the test carried out, the combination of a biological pre-treatment with a plane membrane system showed satisfactory results in terms of wastewater recovery and reuse in the tannery production cycle.

Advanced oxidation processes (AOPs) such as Fenton, electro-Fenton and photo-Fenton have been applied effectively to remove refractory organics from landfill leachate. The Fenton reaction is based on the addition of hydrogen peroxide to the wastewater or leachate in the presence of ferrous salt as a catalyst. The use of this technique has proved to be one of the best compromises for landfill leachate treatment because of its environmental and economical advantages. Fenton process has been used successfully to mineralize wide range of organic constituents present in landfill leachate particularly those recalcitrant to biological degradation. The present study reviews the use of Fenton and related processes in terms of their increased application to landfill leachate. The effects of various operating parameters and their optimum ranges for maximum COD and color removal are reviewed with the conclusion that the Fenton and related processes are effective and competitive with other technologies for degradation of both raw and pre-treated landfill leachate.

This information is current as of ABSTRACT Objective: To investigate clinical, neuropsychological, and MRI abnormalities (gray matter atrophy [GMA] and white matter atrophy [WMA]) in surgical mesial temporal lobe epilepsy (MTLE) patients with and without familial antecedent for epilepsy.

Summary: Purpose: Angelman syndrome (AS) is a neurogenetic disorder characterized by developmental delay and a frequently refractory epileptic condition. Valproate, clonazepam and/or phenytoin are said to be the most effective antiepileptic drugs (AEDs) against the seizures in AS. Experience with the newer AEDs is very limited despite their better safety profile and tolerability. Considering its favorable side effect profile and its effectiveness against both partial and generalized seizures, we hypothesized that lamotrigine (LTG) might be more efficacious and better tolerated.Methods: Potential patients for this retrospective study were identified from the epilepsy clinics at Notre-Dame, Sainte-Justine, and Yale New Haven hospitals. Patients were included in the study if they had AS along with refractory seizures. The medical record of each patient was reviewed with interest on seizure types, previous AEDs and response to LTG.Results: Five patients (2M, 3F) were included in this study. Age at LTG ranged from 10 to 33 years old. All had ≥2 seizure types, mainly generalized tonic–clonic, myoclonic seizures, and atypical absences. Previously tried AEDs included valproic acid (5), benzodiazepines (5), phenytoin (4), carbamazepine (3), and topiramate (1). One patient had pancreatitis on phenytoin, one had worsened seizures on carbamazepine, and one developed hepatic encephalopathy on valproic acid. Three patients became seizure-free with LTG (9, 20, and 36 months FU), one was seizure-free for 1 year with subsequent loss of efficacy, and one showed >50% reduction in myoclonic seizures (20 months FU). No side effects were reported.Conclusion: LTG can be efficacious and well tolerated in patients with AS.

Introduction: Objective assessment of seizure fluctuation in patients with refractory epilepsy in the clinical setting is difficult and subjective assessment may lead to inappropriate changes in medication. We therefore evaluated the utility of Statistical Process Control (SPC) charts as a simple objective clinical tool to demonstrate variability in seizure frequency and to assess the efficacy of drug interventions. Methods: Total weekly seizure frequencies over 1 year were collected for 38 young people with refractory epilepsy. SPC I-charts were generated and Nelson's tests for ''special'' causes of variability applied. In a separate analysis, run charts were reviewed by two epileptologists blinded to clinical data who were asked to identify if and when drug interventions took place. Results: The SPC charts showed that only seven out of 38 (18%) patients had stable seizure frequencies. In the others, they identified significant but short-lived increases in seizure frequency, which were followed by rapid return towards baseline independently of drug changes. A substantial reduction in seizure frequency was associated with a drug increase in only 5 (6.5%) instances. Inter-rater agreement on whether there were drug interventions and their timing was poor (Ä = 0.15, p = 0.4).

The aims of this research is to study and analysis on furnace walls with variation of hot face lining material types, variation of refractory material types, and variation of thickness of insulating materials to outer wall temperature at furnace with working temperature 1000 oC.
This research uses a variety of hot face lining material in the form of ceramic fiber blanket with CR1260, CR1400, and CR1430, variations of refractory material in the form of refractory brick with the type NJM-20, NJM-23, and NJM-26, and using ROCKWOOL as an insulating material with a thickness variation of 50 mm, 75 mm, 100 mm. This research was simulated using Steady State Thermal ANSYS Mechanical (ANSYS Multiphysic) software.

The result of the research shows the difference of the outer wall temperature value of the furnace. The highest wall temperature is in interaction with the wall without insulation, hot face lining material using CR1260, and NJM-26 as refractory material is 75.211 oC. While the lowest wall temperature is in the interaction of 100 mm thick insulation, hot face lining material using CR1430, NJM-20 as refractory material is  46.682 oC.

A significant proportion of depressed patients eventually present with treatment-resistant/refractory major depression (TRD), a debilitating condition that imposes significant health, social, and economic burdens. Recently, a growing level of consensus has been reached on the general meaning of TRD, according to which, depression is considered resistant when at least two trials with antidepressants from different pharmacologic classes (adequate in terms of dose, duration, outcome, and compliance) failed to achieve clinical remission. Regarding the management of TRD, a two-step approach is suggested, involving first the evaluation of factors that may contribute to treatment nonresponse (such as comorbid medical and psychiatric conditions), and second, the use of the four classical strategies for enhancing antidepressant efficacy (namely optimization, augmentation, combination, and switching). Finally, future research on TRD should include studies addressing, among other issues, the validity of the proposed definitional criteria, the evaluation of reliable predictors of treatment outcome, and the development of novel therapeutic strategies.

Silicon nitride-based materials are applied to many tribological components because of their superior thermal and mechanical properties and corrosion resistance. The purpose of this study is to investigate the wear performance of modified silicon nitride which contained 3 wt.% La 2 O 3 and 3 wt.% Y 2 O 3 . The relationships between microstructure and mechanical properties have been also addressed. Vickers microhardness and toughness were measured, the later being determined by means of the direct crack measurement method (DCM). Scanning electron microscopy technique (SEM) coupled with energy dispersive X-ray spectroscopy (EDS) was used for the morphological characterization of the samples as well as for the characterization of the wear scars. Wear properties were studied under a load of 10 N by using the ball-on-disk tribometer. AISI 52100 steel balls and balls of WC + 6% Co (6 mm diameter) were used as static counterparts, respectively. Steady state friction coefficients of 0.66 and 0.62 were measured for the tribological pairs WC + 6 % Co/Si 3 N 4 and AISI 52100/Si 3 N 4 , respectively. The wear mechanism was determined in each case, and comparison between the wear performance of the traditional and modified silicon nitride is also presented.

The productivity of high speed milling operations is limited by the onset of self-excited vibrations known as chatter. Unless avoided, chatter vibrations may cause large dynamic loads damaging the machine spindle, cutting tool, or workpiece and leave behind a poor surface finish. The cutting force magnitude is proportional to the thickness of the chip removed from the workpiece. Many researchers focused on the development of analytical and numerical methods for the prediction of chatter. However, the applicability of these methods in industrial conditions is limited, since they require accurate modelling of machining system dynamics and of cutting forces. In this study, chatter prediction was investigated for orthogonal cutting in turning operations. Therefore, the linear analysis of the single degree of freedom (SDOF) model was performed by applying oriented transfer function (OTF) and \tau decomposition form to Nyquist criteria. Machine chatter frequency predictions obtained from both forms were compared with modal analysis and cutting tests.

Summary:  Purpose: Because the number and variety of patients at any single facility is not sufficient for clinical or statistical analysis, data from six major epilepsy centers that performed multiple subpial transections (MSTs) for medically intractable epilepsy were collected.Methods: A meta-analysis was performed to elucidate the indications and outcome, and to assess the results of the procedure. Overall, 211 patients were represented with data regarding preoperative evaluation, procedures, seizure types and frequencies before and after surgery, postoperative deficits, and demographic information. Fifty-three patients underwent MST without resection.Results: In patients with MST plus resection, excellent outcome (>95% reduction in seizure frequency) was obtained in 87% of patients for generalized seizures, 68% for complex partial seizures, and 68% for simple partial seizures. For the patients who underwent MST without resection, the rate of excellent outcome was only slightly lower, at 71% for generalized, 62% for complex partial, and 63% for simple partial seizures. EEG localization, age at epilepsy onset, duration of epilepsy, and location of MST were not significant predictors of outcome for any kinds of seizures after MST, with or without resection. New neurologic deficits were found in 47 patients overall, comparable in MST with resection (23%) or without (19%).Conclusions: These preliminary results suggest that MST has efficacy by itself, with minimal neurologic compromise, in cases in which resective surgery cannot be used to treat uncontrolled epilepsy. MST should be investigated as a stand-alone procedure to allow further development of criteria and predictive factors for outcome.

Tannery wastewater contains high concentrations of organic matter (COD) with a significant percentage of refractory organic compounds, ammonium substances, salts (i.e. chloride and sulphate) as well as sulphur. Contaminants have to be removed in order to avoid significant environmental impacts. This paper presents the results obtained from a pilot scale study developed in the tannery district of Solofra in Southern Italy. It was aimed at evaluating the reuse of wastewater produced in the retanning process. The treatment process consisted of a biological treatment, as a pre-treatment, followed by a physico-chemical process (with a polymer as a coagulant) and reverse osmosis with a plane membrane. The biological pre-treatment was able to remove approx. 67% of COD, while the membrane system completed the purification process with the removal of the refractory organic compounds (chloride and sulphate). In the test carried out, the combination of a biological pre-treatment with a plane membrane system showed satisfactory results in terms of wastewater recovery and reuse in the tannery production cycle.

A study to improve the integrity and reliability of alumina-based refractory bricks, installed as linings in furnaces and incinerators, is being conducted. Owing to the inherent porosity of such heat-insulating materials, problems associated with molten slag penetration and chemical degradation are often encountered. It is known that denser refractories degrade less rapidly since such penetration is hindered. One aim for the current research is to seal the surfaces of these refractory materials by laser surface processing. In this way the bulk properties of the brick are retained, while the surface properties are improved. This paper reports on the results of an investigation to determine the optimum laser processing parameters that produce a zone of densified material containing few defects at the refractory surface. The high thermal stresses usually associated with laser treatment are often relieved by fracture of the laser-treated zone. However, by using a novel flame-assisted laser surface treatment, a reduction in thermal stress has been achieved, resulting in a crack-free, dense laser-treated zone. This treated zone should reduce or even eliminate the ingress of molten slags and gases, thus providing a reduced area for attack by corrosive species.

Summary: Purpose: West syndrome is a rare epileptic syndrome associated with infantile spasms, a specific abnormal electroencephalographic pattern (termed hypsarrhythmia). and mental retardation. Management of this disorder is difficult because current treatment regimens, including many anticonvulsants and hormones, are often ineffective. Topiramate (TPM) is a new antiepileptic drug that may be effective in pediatric epilepsies. We conducted a pilot study to test the effects of rapid TPM dosing in patients with refractory infantile spasms.Methods: Eleven children with refractory infantile spasms were given an initial dose of 25 mg TPM per day in addition to their current therapy. Dosage was increased by 25 mg every 2–3 days until spasms were controlled, the maximal tolerated dose was reached, or the maximal dose of 24 mg/kg/day was achieved. Efficacy was primarily assessed by video EEG and secondarily by parental count of spasm frequency.Results: Five (45%) subjects became spasm free during the study, with absence of infantile spasms and hypsarrhythmia (either classic or modified) proven by video EEG. Nine subjects, including the five spasm free, achieved a spasm reduction of 250%. Spasm frequency decreased from 25.6 f 19.3 to 6.9 r 5.9 spasmdday. Sixty-four percent of the subjects were able to achieve TPM monotherapy.Conclusions: Results in this cohort of 11 patients with refractory disease show TPM to be a promising new agent for the treatment of infantile spasms.

The time course of colored dissolved organic matter (CDOM) absorption and fluorescence were monitored during 50 to 70 days of laboratory incubations with water collected in the coastal upwelling system of the Ría de Vigo (NW Iberian Peninsula) under contrasting hydrographic conditions. CDOM fluorescence at peak-T (Ex/Em, 280/350 nm), characteristic of protein-like materials, decayed at a 1st order degradation rate constant (k T ) of 0.28± 0.13 day − 1 (average ± SD). k T covaried (R 2 = 0.86, p b 0.0002) with the degradation rate of the bulk DOC (k DOC ), but the protein-like materials degraded 72 ± 23% faster than DOC. Therefore, this study confirms that the CDOM fluorescence at peak-T can be used as a proxy to a DOM fraction significantly more labile than the bulk bioavailable DOC. In parallel with the decay of DOC and protein-like fluorescence, an increase in CDOM fluorescence at peak-M (Ex/Em, 320/410 nm) during the course of the incubations verified the production of marine humic-like substances as a by-product of the microbial metabolism. CDOM fluorescence at peak-M built-up at a production rate (k M ) of 0.06 ± 0.01 day − 1 (average ± SD) in the Ría de Vigo. Furthermore, the slope of the linear regression between k DOC and k M (R 2 = 0.64, p b 0.001) revealed that the formation of marine humic-like substances occurred at about one fifth of the rate of net DOC consumption.

Refractory celiac disease (RCD) is one of the most serious causes of persistent symptoms in patients with celiac disease (CD). Published reports suggest that approximately half of patients in Europe are RCD type II, which carries a poor prognosis with a 5-year survival rate of ~ 50 % compared with ~ 90 % for RCD type I. However, disease patterns may be different in North America. The aim of this study was to explore the clinical spectrum of RCD in a North American population.

Adult idiopathic inflammatory myopathies, commonly referred to as myositis, are a heterogeneous group of diseases with an autoimmune etiology. In this review, the authors are going to focus on myositis excluding inclusion body myositis. They will review the prognostic factors (for mortality and response to steroids), define refractory disease, introduce a new concept (presumed refractory disease), analyze definitions of active disease, damage and improvement criteria, and summarize therapeutic alternatives for refractory patients, based on different disease phenotypes.

Focal cortical dysplasia (FCD) is often associated with severe partial epilepsy. In this study, we performed magnetoencephalography (MEG) and electrocorticogrsphy (ECoG) on four patients with FCD-associated epilepsy to confirm the 'intrinsic' epileptogenicity of FCD. In all patients, we determined the three-dimensional locations of the magnetic sources of the interictal paroxysmal activities by a single dipole model, and then the estimated dipole localization was superimposed on the magnetic resonance image. The dipole clusters were located in the T2-prolonged lesions, namely in the FCD lesions themselves. All patients underwent surgery for their medically intractable epilepsy, and the acute and/or chronic ECoG were thereafter recorded. Either frequent or continuous paroxysmal activities were recorded from the ECoG electrodes which were placed over the surface of the FCD lesion, while few paroxysmal activities were observed on the normal appearing adjacent cortex. Intraoperative depth recordings were performed in a patient with the needle electrode inserted into the FCD lesion and they revealed these paroxysmal foci to be located not on the cortical surface but at a depth of 15 mm from the cortical surface where both abnormal giant neurons and bizarre large eosinophilic cells (so-called balloon cells) were also prominently observed on the postoperative histological sections. Following a lesionectomy combined with the removal of the underlying white matter, three patients demonstrated a favorable seizure outcome. Our findings thus suggest the FCD lesions to be highly and intrinsically epileptogenic lesions.

The effect of carbon aggregates on the carbon refractory properties for a blast furnace was studied with X-ray diffraction (XRD), scanning electron microscopy (SEM), an energydispersive X-ray, mercury porosimetry, a resistivity instrument, and a laser thermal conductivity meter. The results showed that the microporous structure of a sample was determined by the amount of b-SiC whiskers. The thermal conductivity was controlled by the thermal conductivity of the corresponding carbon aggregate, and the alkali and molten-iron attack was decided mainly by the pore and the graphitization degree of aggregate, respectively. For samples using calcined anthracites as aggregates, the microporous structure became worse, the thermal conductivity increased, and the molten-iron as well as the alkali attack became more severe with an increase in the anthracite calcining temperature. For all samples, microcrystalline graphite possessed the best microporous structure and the least alkali and molten-iron attack, whereas the graphite electrode scraps had the highest thermal conductivity and the most severe alkali and molten-iron attack.

Municipal solid waste incineration (MSWI) bottom ash contains a considerable amount of heavy metals. The occurrence and uneven distribution of these heavy metals in bottom ash can increase the complexity of such residues in terms of long-term behavior upon landfilling or recycling. Bottom ashes sampled from three stoker-type incinerators in Japan were analyzed in this paper. This study presents detailed information on the mineralogical characterization of bottom ash constituents and the weathering behavior of these constituents by means of optical microscopy and scanning electron microscopy. It was revealed that bottom ash mainly consists of assorted silicate-based glass phases (48-54 wt% of ash) and mineral phases including melilites, pseudowollastonite, spinels, and metallic inclusions (Fe-P, Fe-S, Fe-Cu, Cu-Sn, Cu-Zn, Cu-S, and Cu-Pb dominated phases), as melt products formed during the incineration process. The compounds embedded in the glass matrix, e.g. spinels and metallic inclusions, played the most important role in concentration of heavy metals (Pb, Zn, Cu, Cr, Mn, Ni, etc.). Other phases such as refractory minerals and ceramics, frequently found in ash, were of less significance in terms of their influence on the involvement of heavy metals. Analysis of lab-scale artificially weathered and 10-year landfilled bottom ash samples revealed that secondary mineralization/alteration of the bottom ash constituents principally carbonation and glass evolution substantially decreased the potential risk of the heavy metals to the surrounding environment.

Objectives: IV cyclosporin A (CSA) is an effective therapy in patients with severe ulcerative colitis (UC). It remains unclear if this treatment affects the course of the disease in the long run. We investigated the long-term efficacy and safety in 86 patients with ulcerative colitis treated with IV CSA at our center.

Objective. The primary aim of the study was to assess the incidence of intracavitary pathology visualized by saline infusion sonohysterography (SIS) in premenopausal women suffering from abnormal uterine bleeding refractory to medical therapy. Secondary aims were to evaluate the clinical course when a minimally invasive therapeutic approach was applied and to examine the need for hysterectomy in this group of women over a follow-up period of two years. Design. Prospective cohort study. Setting. Tertiary referral university hospital. Population. Between February 2004 and June 2006, 104 premenopausal women suffering from abnormal uterine bleeding refractory to medical treatment were included. Methods. Transvaginal ultrasonography and SIS were performed as first line procedures of the investigation. Hysteroscopy was undertaken for removal of focal intrauterine anomalies. Hysterectomy was only carried out when other approaches failed or were regarded as unsuitable. Women who did not undergo hysterectomy had regular follow-up consultations for at least two years. Main outcome measures. Incidence of intrauterine focal anomalies, clinical course, and need for hysterectomy. Results. Following saline infusion sonohysterograhy intracavitary anomalies were visualized in 58 (55.8%) women. Over the follow-up period 80 women had successful minimally invasive treatment, while 24 women underwent hysterectomy. Conclusions. The study shows that focal intracavitary lesions are common in premenopausal women with abnormal uterine bleeding refractory to medical treatment. By applying minimally invasive diagnostic and therapeutic approaches acceptable bleeding patterns can be re-established in most cases, thereby resulting in a low rate of hysterectomies.