Process design and techno-economic analysis of activated carbon derived from anthracite coal.

Activated carbon (AC), renowned for its versatile applications in water treatment, air purification, and industrial processes, is a critical component in environmental remediation and resource recovery strategies. This study encompasses the process modeling of AC production using anthracite coal as a precursor, involving multiple activation stages at different operating conditions, coupled with a detailed techno-economic analysis aimed at assessing the operational feasibility and financial viability of the plant. The economic analysis explores the investigation of economic feasibility by performing a detailed cashflow and sensitivity analysis to identify key parameters influencing the plant's economic performance, including raw material and energy prices, operational and process parameters. Capital and operational costs are meticulously evaluated, encompassing raw material acquisition, labor, energy consumption, and equipment investment. Financial metrics like Net Present Value (NPV), Internal Rate of Return (IRR), and payout period (POP) are employed, and the results show that AC selling price, raw material cost and plant capacity are the most influential parameters determining the plant's feasibility. The minimum AC production cost of 1.28 $/kg is obtained, corresponding to coal flow rate of 14,550 kg/h. These findings provide valuable insights for stakeholders, policymakers, and investors seeking to engage in activated carbon production from anthracite.

Differences in curve behavior after fusion in adolescent idiopathic scoliosis patients with open triradiate cartilages.

STUDY DESIGN: Retrospective review. OBJECTIVE: To compare the results of spinal fusion in patients with open triradiate cartilages (OTRC) and closed triradiate cartilages (CTRC). SUMMARY OF BACKGROUND DATA: Patients with OTRC at the time of spinal fusion may be at increased risk of developing postoperative changes related to growth. METHODS: From a database of patients with adolescent idiopathic scoliosis, we identified 44 patients with OTRC (mean age, 11.6 years) and 450 patients with CTRC (mean age, 15.6 years) and a minimum follow-up of 2 years. Patients in both groups were treated with anterior-only, posterior-only, or combined anterior and posterior spinal fusion; none had all-pedicle screw posterior instrumentation. RESULTS: In the OTRC group, anterior or posterior instrumentation, but not the combined approach, resulted in a significant mean late increase in the main curve (4.4 degrees and 7.3 degrees vs. 0 degrees , respectively; P = 0.002), an approach-related difference not seen in the CTRC group. Significantly more OTRC patients had proximal levels added on after surgery than did CTRC patients (18% vs. 8%, respectively; P = 0.02), and there was a trend toward this phenomenon distally (29% vs. 19%, respectively; P = 0.10). Proximal and distal junctional kyphosis was not significantly different between the 2 groups. Reoperation rate was 11% and 7% for OTRC and CTRC patients, respectively. For the selectively fused Lenke 1C curves in OTRC and CTRC patients, there was a trend in the uninstrumented lumbar curve toward a smaller lumbar curve before surgery (36 degrees and 41 degrees , respectively; P = 0.07) and a larger curve after surgery (27 degrees and 24 degrees , respectively; P = 0.07). CONCLUSION: Patients with scoliosis and OTRC have a greater risk of adding-on proximally and of loss of correction with anterior-only instrumentation; they may also have less predictable lumbar correction from selective thoracic fusion. However, after combined surgery, they have results similar to those of more skeletally mature patients.

Operative management of Scheuermann's kyphosis in 78 patients: radiographic outcomes, complications, and technique.

STUDY DESIGN: A retrospective multicenter review of 78 patients with Scheuermann's kyphosis treated operatively was conducted. OBJECTIVE: The purpose of this study was to evaluate correction of sagittal alignment, maintenance of correction, and occurrence of, and etiologic factors associated with, junctional kyphosis in patients managed operatively for Scheuermann's kyphosis. SUMMARY OF BACKGROUND DATA: There is a paucity of literature regarding the surgical treatment of Scheuermann's kyphosis using current implant systems and operative techniques. Junctional kyphosis has been shown to occur in up to one third of patients. Factors causing junctional kyphosis have not been clearly elucidated. Loss of correction has been variable based on the technique used. No clear-cut advantages or disadvantages have been shown for the use of anterior release. METHODS: Kyphosis, lordosis, C7 sagittal plumbline, apical translation, junctional sagittal alignment, and pelvic incidence were assessed among other radiographic parameters from a centralized database. The incidence of junctional kyphosis and its association to the above parameters and to fusion levels were assessed. Complication rates and differences between patients undergoing combined anteroposterior surgery and those having posterior surgery alone were evaluated. RESULTS: Of the 78 patients, 42 underwent combined anteroposterior procedures (Group 1) and 36 had posterior surgery only (Group 2). Mean age was 16.7 years. Overall, the greatest Cobb kyphosis of 78.8 degrees was corrected to 51.4 degrees at follow-up. Preoperative kyphosis was 82.6 degrees and 74.4 degrees for Groups 1 and 2, respectively (P < 0.001) and 55.8 degrees and 46.2 degrees at follow-up (P = 0.000). Loss of correction was 3.2 degrees (not significant) and 6.4 degrees (P = 0.000), respectively. Lordosis corrected from -65.5 degrees to -51.7 degrees . Proximal and distal junctional kyphosis of >or=10 degrees occurred in 25 (32.1%) and 4 (5.1%), respectively. The development of a proximal junctional kyphosis correlated directly with kyphosis at follow-up and indirectly with percent correction. Among patients with proximal junctional kyphosis, the magnitude of junctional kyphosis correlated directly with the degree of pelvic incidence. Pelvic incidence correlated directly with lumbar lordosis but not kyphosis. Twelve complications occurred in 12 patients, including posterior wound infection (1), distal (2), and proximal (1) junctional kyphosis, and pseudarthrosis (1), those requiring reoperation. CONCLUSION: This is one of the largest reported series of Scheuermann's kyphosis treated operatively to our knowledge. A high rate of junctional kyphosis, especially at the proximal end, is associated with surgery for Scheuermann's kyphosis using current techniques. Proximal junctional kyphosis is associated with higher magnitude of kyphosis at follow-up, less percent correction; its magnitude correlated directly with pelvic incidence. Loss of correction is less in patients undergoing combined anteroposterior surgery. Pelvic incidence correlates directly with lordosis but not kyphosis, suggesting that these parameters are not causative of Scheuermann's kyphosis.

Surgical rates and operative outcome analysis in thoracolumbar and lumbar major adult scoliosis: application of the new adult deformity classification.

STUDY DESIGN: Multicenter prospective consecutive clinical series. OBJECTIVE: Investigate the interaction between the Adult Deformity Classification and treatment patterns, surgical strategies, surgery effectiveness, and complication rates. SUMMARY OF BACKGROUND DATA: An Adult Deformity Classification has been established that applies radiographic parameters of disability. Preliminary intraobserver and interobserver analysis reveals excellent reliability of the classification. Outcomes studies have not been reported to date. METHODS: A total of 784 adult patients with thoracolumbar or lumbar deformity underwent radiographic evaluation (full-length frontal/sagittal) as well as health assessment: Oswestry Disability Index, Scoliosis Research Society-22, and SF-12. Patients were subdivided by treatment and surgical strategies; 1 year (111 patients) and 2 year (45 patients) follow-up data were analyzed. Interaction between classification, treatment, surgical strategy, health assessment changes, and complications were analyzed. RESULTS: Classification modifiers (lordosis, subluxation, sagittal balance) were found to have significant variation (higher rates) in surgical care as the grade of the modifier increased. Classification differentiated patients by surgical approach and/or technique. Interaction between classification and baseline health assessment impacts both postoperative health scores and complication rates. CONCLUSION: This investigation appears to offer the first comprehensive analysis of classification, treatment, and outcomes in a large adult deformity patient group. Significant treatment patterns and outcomes are coming to light as is the impact of surgical strategy.

Long-term outcome of autologous transplantation of peripheral blood progenitor cells as postremission management of patients > or =60 years with acute myelogenous leukemia.

The optimal postremission treatment for elderly patients with acute myelogenous leukemia (AML) is presently unknown, but recent studies report the feasibility of autologous stem cell transplantation in this population. To better understand the long-term outcome of autologous transplantation in AML patients > or =60 years of age, we evaluated high-dose chemoradiotherapy preparative conditioning followed by transplantation of peripheral blood progenitor cells procured after a single cycle of cytarabine-based consolidation chemotherapy as postremission therapy in 27 patients aged 60 to 71 years (median age, 65 years) with newly diagnosed AML in first complete remission (CR). The median follow-up from CR for all patients was 13.6 months (range, 6.0-123.1 months). The median follow-up from remission for surviving patients was 81 months (range, 41.4-123.1 months). Seven patients are alive in continuous CR, 19 died from relapse, and 1 died as a result of treatment-related infection. Leukemia-free survival and overall survival are 10.3 and 13.4 months, respectively. Actuarial leukemia-free and overall survival at 3 years are 25% +/- 9% and 28% +/- 9%, respectively. Our results demonstrate that autologous transplantation of peripheral blood progenitor cells is well tolerated and feasible for patients > or =60 years of age with AML in first CR. Future investigation should focus on a randomized study evaluating a larger group of elderly patients in first CR comparing autologous stem cell transplantation with conventional cytarabine-based consolidation chemotherapy to identify the optimal postremission therapy.

Use of video-assisted thoracoscopic surgery to reduce perioperative morbidity in scoliosis surgery.

STUDY DESIGN: A case series of idiopathic scoliosis patients treated with thoracoscopic anterior instrumentation was compared to a similar group of patients treated by open anterior instrumentation. OBJECTIVES: To evaluate the morbidity associated with thoracoscopic instrumentation compared to the open approach for thoracic scoliosis. METHODS: A consecutive group of thoracoscopically treated patients with Lenke 1 adolescent idiopathic scoliosis was compared to similar patients gathered from the DePuy-AcroMed Harms Study Group database. Perioperative outcome measures as well as early postoperative functional outcomes (pulmonary function, shoulder strength) were compared. RESULTS: There were 38 thoracoscopic instrumentation cases with greater than 6 months' follow-up that were compared to 68 anterior open instrumentation cases. The radiographic outcomes were similar (60% +/- 11% vs. 59% +/- 17% thoracic curve correction for the thoracoscopic and open groups, respectively). The reduction in forced vital capacity was significantly (P = 0.01) greater in the open group (0.6 +/- 0.3 L) compared to the endoscopic group (0.4 +/- 0.3 L). There was a trend towards greater return of shoulder girdle strength and range of motion 6 weeks after surgery in the thoracoscopic patients. CONCLUSION: The thoracoscopic approach for instrumentation of scoliosis has advantages of reduced chest wall morbidity compared with the open thoracotomy method but allows comparable curve correction.