Preparation and Characterization of Poly(Methyl Methacrylate) Grafted Sago Starch

The graft copolymerization of poly(methyl methacrylate) (PMMA) onto sago starch (sago starch-g-PMMA) was carried out using ceric ammonium nitrate (CAN) and potassium persulfate (PPS) as initiators. PMMA was first grafted onto sago starch using CAN as an initiator under nitrogen gas atmosphere. The maximum percentage of grafting (%G) was detennined to be 2460/0 when the optimum conditions (reaction temperature: 70 DC, reaction period: 2 hrs, the amount of CAN: 2.0 mmoles, the amount of nitric acid: 0.4 mmoles, and the amount of methyl methacrylate (MMA): 141 mmoles). When PPS was used as an initiator, the maximum % G achieved was 900/0. The optimum conditions for this initiator were as follows: reaction temperature: 50 oC, the amount of monomer: 47 mmoles, the amount of PPS: 1.82 mmoles, and reaction period: 1.5 hr. The copolymers produced were characterized by Fourier Transform Infrared Spectrophotometry (FTIR) , differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The FTIR spectra of the copolymers clearly indicated the presence of characteristic peaks of PMMA and sago starch, which suggested that PMMA had been successfully grafted on the sago starch. DSC and TGA thermograrns showed that the copolymerization products were made up of two different polymers. The copolymers of vanous percentages of grafting were hydrolysed with 0.5 M hydrochloric acid and the viscosity measurements of PMMA produced were carried out using Ubbelohde viscometer. The average molecular weight (Mv) of PMMA grafted onto the sago starch (2460/0G) prepared by using CAN as the initiator was 4.3xlO4, and from PMMA grafted sago starch (900/00) prepared by using PPS as the initiator was 1.3x 104. Biodegradability studies of sago starch-g-PMMA and sago starch were carried out by a-amylase enzyme. The rate of degradation of sago starch was higher than the rate of degradation of sago starchg- PMMA. Maximum biodegradation of the sago starch was achieved after 3 days of incubation, while for the copolymer was 7 days

Surgical resection of neoplastic cervical spine lesions in relation to the vertebral artery V2 segment

Neoplastic cervical spine lesions are seen infrequently by the spinal surgeon. The surgical management of these tumors, particularly with associated neurovascular compromise, is challenging in terms of achieving proper resection and spinal stabilization and ensuring no subsequent recurrence or failure of fixation. In this report we highlight some of the problems encountered in the surgical management of tumors involving the cervical spine with techniques applied for gross total resection of the tumor without compromising the vertebral arteries. Ten patients with neoplastic cervical spine lesions were managed in our study. The common cardinal presentation was neck and arm pain with progressive cervical radiculo-myelopathy. All patients had plain X-rays, computer tomography scans, and magnetic resonance imaging of the cervical spine. Digital subtraction or magnetic resonance angiograms were performed on both vertebral arteries when the pathology was found to be in proximity to the vertebral artery. When a tumor blush with feeders was evident, endovascular embolization to minimize intraoperative bleeding was also considered. A single approach or a combined anterior cervical approach for corpectomy and cage-with-plate fixation and posterior decompression for resection of the rest of the tumor with spinal fixation was then accomplished as indicated. All cases made a good neurological recovery and had no neural or vascular complications. On the long-term follow-up of the survivors there was no local recurrence or surgical failure. Only three patients died: two from the primary malignancy and one from pulmonary embolism. This report documents a safe and reliable way to deal with neoplastic cervical spine lesions in proximity to vertebral arteries with preservation of both arteries

Physico-Chemical Changes In Sugarcane (Saccharum Officinarum Var. Yellow Cane) And The Extracted Juice During Development, Maturation And Postharvest Treatments Upon Storage

A study was conducted to determine the physico-chemical changes between different portions (top, middle, and bottom) of sugarcane at different maturity stages (between 3 and 10 months from planting). The variety used was Saccharum officinarum var. Yellow cane. The parameters analysed were weight, diameter, yield, total colour of juice, total soluble solids (TSS), pH, titratable acidity, sugar content (sucrose, glucose, fructose), tannin, chlorophyll and polyphenol oxidase (PPO) activity. The weight, diameter, total soluble solids (TSS) and sucrose content increased significantly (P<O.01 ) for sugarcane from all portions (top, middle and bottom) until the end of maturity stage. On the other hand, titratable acidity (TA) values, pH, juice yield, glucose, fructose contents, tannin, chlorophyll and PPO decreased significantly (P<O.0 1 ) during maturity. Significant differences were also detected in all the parameters between the different portions during maturity. Results obtained indicated that there were significant decreases (P<0.01) in tannin and chlorophyll contents during maturity

Synthesis, Characterization and Application of Polyacrylamide Grafted Sago Strach for Coagulation and Flocculation Processes

Graft copolymerization of polyacrylamide (PAm) onto sago starch (S.S), S.S-g-PAml, SS-g-PAm2, S.S-g-PAm3, and S.S-g-PAm4, were carried out by a free radical initiation using cerric ion (CAN)-induced redox polymerization technique at 30+1°C, and under nitrogen gas atmosphere by varying the amount of CAN and PAm. The copolymers produced were characterized by Fourier Transform Infrared Spectrophotometry (FT-IR), Thermogravimetric analysis (TGA), elemental and gravimetric analyses. The FT-IR spectra of the copolymers clearly indicated the presence of characteristic peaks of PAm and sago starch, which suggested that PAm had been successfully grafted onto the sago starch. TGA thermograms showed that the copolymerization products were made up of two different polymers. The copolymers of various percentages of yield and conversion were hydrolyzed with 0.5 M hydrochloric acid and the viscosity measurements of PAm produced from the copolymers were carried out using Ubbelohde viscometer. The average molecular weight of the side chains (Mv) of the copolymers were 5.6~105, 3.1 xlO5, 7.4 xlO5, and 2.0 x105 respectively and viscosity values were 251.97, 157.52, 314.43 and 110.02 mL/g respectively. A series of standard jar tests were conducted in order to evaluate the performance of the polymers prepared (S.S-g-PAm) in kaolin suspension. Among the graft copolymers, SS-g-PAml was selected based on the performance and sago starch content to be used in further experiments; further more, a series of standard jar tests were conducted to optimize the operation conditions of S.S-g-PAml in bringing down the turbidity of supernatant liquid of 200 NTU kaolin suspension by varying the following parameters: dosage, pH, speed of rapid mixing, time of rapid mixing, speed of low mixing, and time of low mixing. And the optimum conditions were found to be 0.5 mg/L, 6.3, 75 rpm, 4 minutes, 25 rpm, 5 minutes respectively. Substantial reduction of residual turbidity was achieved by S. S-g-PAm. Settling column analysis was established for S.S-g-PAml in low, medium to high (50, 200, 300 NTU, respectively) initial kaolin suspension turbidity. Initial turbidity and settling time were found to be one of the major factors in settling water coagulated with S.S-g- PAml. Residual turbidity was found to decrease with increasing settling time; the decrease was higher for kaolin water with higher initial turbidities. Four river samples were collected from two locations; two samples of low and medium to high turbidity (30.5, 780 NTU), respectively were collected from Hulu Langat Water Treatment Plant, and another two samples of the same level of turbidity (low and medium to high turbidity) (68 and 450 NTU), respectively were collected from Semenyih Water Treatment Plant. Samples of low to high turbidities from two different rivers in Malaysia were collected and compared with the existing coagulant (liquid alum) that is being widely used by the treatment plants. The performance of S.S-g-PAml were found to be good as compared to liquid alum with the advantages of the biodegradability of S.S-g-PAml as well as less dosage of S.S-g-PAml used as compared to liquid alum

Physico-chemical changes in sugarcane (Saccharum officinarum var yellow cane) and the extracted juice at different portions of the stem during development and maturation

A study was conducted to determine the physicochemical differences between portions (top, middle, and bottom) of sugarcane at different maturation stages (between 3 and 10 months from planting). The variety used was Saccharum officinarum var. Yellow cane. The parameters analysed were weight, diameter, yield, total soluble solids (TSS), pH, titratable acidity, sugar content (sucrose, glucose, fructose). The weight, diameter, total soluble solids (TSS) and sucrose content increased significantly (P<0.01) in all portions (top, middle and bottom) up to the end of maturity. On the other hand, titratable acidity (TA), pH, juice yield, glucose and fructose contents decreased significantly (P<0.01) during maturation. However, significant differences were also detected in weight, diameter, TSS, sugar content, pH, TA and juice yield between the different portions during maturation. Sucrose content, juice yield and TSS were found to be the most suitable indicators of maturity, while TA, glucose and fructose contents were found to be poor maturity indicators. A suitable harvesting stage was found to be between 7 and 8 months after planting. Copyright © 2001 Elsevier Science Ltd

BE-P32: fabrication of Nahar Seed Oil for biolubricant production

In this study, a laboratory scale for extraction and analysis of Nahar (Mesua ferrea L.) seed oil (NSO) for biolubricant production was conducted. The oil was extracted then analyzed the chemical and physical properties and studied its current and potentially future use in lubricant applications, as both base oil and additives. The analysis includes moisture content, free fatty acids (FFA%), saponification value (SV), iodine value (IV), unsapoifiable matters and phosphorus content. After that the NSO was undergo an esterification process and two-step transesterification processes to increase its viscosity for production of biolubricant. The reaction temperature, the reaction time, and the catalyst dosage (sodium methoxide) were the chosen parameters in the optimization processes of the Nahar seed oil (NSO) biolubricant production. From the result obtained, the maximum viscosity of NSO biolubricant was achieved when the temperature was 150oC, 80 min in reaction time and 0.8% catalyst dosage

Therapeutic approaches to cerebral vasospasm complicating ruptured aneurysm

Cerebral vasospasm is a serious complication of ruptured aneurysm. In order to avoid short- and long-term effects of cerebral vasospasm, and as there is no single or optimal treatment modality employed, we have instituted a protocol for the prevention and treatment of vasospasm in patients suffering aneurysmal sub-arachnoid hemorrhage (SAH). We then reviewed the effectiveness of this protocol in reducing the mortality and morbidity rate in our institution. In this study we present a retrospective analysis of 52 cases. Between March 2004 and December 2008 52 patients were admitted to our service with aneurysmal SAH. All patients commenced nimodipine, magnesium sulphate (MgSO4) and triple H therapy. Patients with significant reduction in conscious level were intubated, ventilated and sedated. Intracranial pressure (ICP) monitoring was used for intubated patients. Sodium thiopental coma was induced for patients with refractory high ICP; angiography was performed for diagnosis and treatment. Balloon angioplasty was performed if considered necessary. Using this protocol, only 13 patients (25%) developed clinical vasospasm. Ten of them were given barbiturates to induce coma. Three patients underwent transluminal balloon angioplasty. Four out of 52 patients (7.7%) died from severe vasospasm, 3 patients (5.8%) became severely disabled, and 39 patients (75%) were discharged in a condition considered as either normal or near to their pre-hemorrhage status. Our results confirm that the aforementioned protocol for treatment of cerebral vasospasm is effective and can be used safely

Development of a wastewater treatment system for chromium removal using chitosan

This study attempts to evaluate the removal of chromium from aqueous solution using chitosan as an adsorbent. The experiment was conducted by varying chitosan dosage (10-30 mg), pH (5-8), contact time (10-90 min) and agitation speed (50-250 rpm). The initial Cr concentration was fixed to 20 mg L-1. The results indicated that pH is the most significant factor that affects the removal of Cr. The R2 of 0.9963 showed that the overall model is good as the experimental values are close to predicted values. The optimized conditions obtained at 28.79 mg chitosan dosage, pH 6.40, 20.20 min contact time and agitation speed of 156.20 rpm. This optimum condition obtained to achieve 0.05 mg L-1 residual Cr concentration or 99.75% removal that meets Department of Environment Malaysia (DOE) effluent discharge requirement. The design of treatment system that consists of rapid mix, sedimentation and filtration unit is based on the optimum operating conditions. Rapid mix tank was designed with surface area of 9.18 m2 and volume of 27.8 m3. Sedimentation basin was designed with surface area of 100 m2 and volume of 83.33 m3. Filtration was designed with surface area of 16.67 m2