An Overview of Spark Ignition Engine Operating on Lower-Higher Molecular Mass Alcohol Blended Gasoline Fuels

This paper reviews the utilization of lower and higher molecular weight alcohols as fuel for spark ignition engine. As an alternative fuel for spark ignition engine, alcohol is widely accepted as comparable to gasolin. It is due to its ability that can be produced from biological matter through the current available and new processes. Moreover, alcohol is also considered as fuel additive due to its physical and chemical properties compatible with the requirements of modern engines. The objective of this paper is to provide an overview of these fuels by highlighting on the fuel properties and spark ignition engine responses. The first part of this review explains the important of alcohol fuel properties related to the engine performance and emissions, and the difference of these properties for each type of alcohol. The second part discusses recent advancements in research involving lower and higher molecular weight alcohols mainly responses from spark ignition engine

Blunt traumatic aortic injury: Initial experience with endovascular repair

ObjectivesEndovascular treatment of traumatic aortic injury (TAI) is an alternative to open repair (OR) in patients with blunt trauma. We report our initial experience after integration of endovascular repair using thoracic devices.MethodsA retrospective review of a prospectively collected institutional trauma registry was performed. Between September 2005 and November 2008, 71 patients with TAI presented to our institution. Based on imaging, TAIs were classified into grade 1-4 in severity. These included: grade 1, intimal tear; grade 2, intramural hematoma; grade 3, aortic pseudoaneurysm; and grade 4, free rupture. Initial management included resuscitation, blood pressure control, and treatment of associated injuries. After stabilization, all patients were considered for thoracic endovascular aortic repair (TEVAR) using a thoracic device. If contraindicated, candidates underwent OR. Outcome measures were mortality, stroke, paraplegia, intensive care unit (ICU), and hospital stay.ResultsThe mean age was 39.8 years, with 50 males. The mean injury severity score (ISS) was 42.6. Nineteen (27%) patients with a mean ISS of 60 died shortly after arrival prior to any vascular intervention. Ten (14%) patients with grade 1 injuries were managed medically. The remaining 42 (59%) patients with grade 2 and 3 injuries underwent repair. Median interval between admission and repair was 4.3 days (range, 0-109 days). Fifteen (21%) patients with a mean ISS of 34.4 underwent OR with no mortality, stroke, or paraplegia. Twenty-seven (38%) patients with a mean ISS of 36.7 underwent TEVAR with no mortality or paraplegia. One TEVAR patient suffered a perioperative stroke. Twenty-two patients had a TAG (W.L. Gore & Associates, Flagstaff, Ariz) device. Four patients had a Talent Thoracic (Medtronic Vascular, Santa Rosa, Calif), and 1 patient had an Excluder (W.L. Gore) device. The left subclavian artery was covered in 13 (48%) patients. Patients who underwent TEVAR were older than those who had OR (47.8 vs 31.1 years, P < .006). The aortic diameter proximal to the injury was larger in the TEVAR group (24.4 vs 19.6 mm, P < .0001). There was no difference in the mean ICU or hospital length of stay between the two groups. Mortality correlated with the ISS score (P < .0001). Median follow-up time was 19.4 months (range, 0-27). Only 56% of the TEVAR patients were fully compliant with their surveillance imaging protocol.ConclusionIn this initial experience, the results of TEVAR did not differ from OR. Long-term follow-up is required to determine the effectiveness of this treatment strategy. Adherence to follow-up imaging protocols is challenging in this patient population. Next generation devices will make TEVAR applicable to a wider range of patients

Postoperative renal function preservation with nonischemic femoral arterial cannulation for thoracoabdominal aortic repair.

BACKGROUND: Renal failure after thoracoabdominal aortic repair is a significant clinical problem. Distal aortic perfusion for organ and spinal cord protection requires cannulation of the left femoral artery. In 2006, we reported the finding that direct cannulation led to leg ischemia in some patients and was associated with increased renal failure. After this finding, we modified our perfusion technique to eliminate leg ischemia from cannulation. In this article, we present the effects of this change on postoperative renal function. METHODS: Between February 1991 and July 2008, we repaired 1464 thoracoabdominal aortic aneurysms. Distal aortic perfusion was used in 1088, and these were studied. Median patient age was 68 years, and 378 (35%) were women. In September 2006, we began to adopt a sidearm femoral cannulation technique that provides distal aortic perfusion while maintaining downstream flow to the leg. This was used in 167 patients (15%). We measured the joint effects of preoperative glomerular filtration rate (GFR) and cannulation technique on the highest postoperative creatinine level, postoperative renal failure, and death. Analysis was by multiple linear or logistic regression with interaction. RESULTS: The preoperative GFR was the strongest predictor of postoperative renal dysfunction and death. No significant main effects of sidearm cannulation were noted. For peak creatinine level and postoperative renal failure, however, strong interactions between preoperative GFR and sidearm cannulation were present, resulting in reductions of postoperative renal complications of 15% to 20% when GFR was \u3c60 mL\u3e/min/1.73 m(2). For normal GFR, the effect was negated or even reversed at very high levels of GFR. Mortality, although not significantly affected by sidearm cannulation, showed a similar trend to the renal outcomes. CONCLUSION: Use of sidearm cannulation is associated with a clinically important and highly statistically significant reduction in postoperative renal complications in patients with a low GFR. Reduced renal effect of skeletal muscle ischemia is the proposed mechanism. Effects among patients with good preoperative renal function are less clear. A randomized trial is needed

Nanoparticle sensor for label free detection of swine DNA in mixed biological samples

We used 40 ± 5 nm gold nanoparticles (GNPs) as colorimetric sensor to visually detect swine-specific conserved sequence and nucleotide mismatch in PCR-amplified and non-amplified mitochondrial DNA mixtures to authenticate species. Colloidal GNPs changed color from pinkish-red to gray-purple in 2 mM PBS. Visually observed results were clearly reflected by the dramatic reduction of surface plasmon resonance peak at 530 nm and the appearance of new features in the 620–800 nm regions in their absorption spectra. The particles were stabilized against salt-induced aggregation upon the adsorption of single-stranded DNA. The PCR products, without any additional processing, were hybridized with a 17-base probe prior to exposure to GNPs. At a critical annealing temperature (55 °C) that differentiated matched and mismatched base pairing, the probe was hybridized to pig PCR product and dehybridized from the deer product. The dehybridized probe stuck to GNPs to prevent them from salt-induced aggregation and retained their characteristic red color. Hybridization of a 27-nucleotide probe to swine mitochondrial DNA identified them in pork–venison, pork–shad and venison–shad binary admixtures, eliminating the need of PCR amplification. Thus the assay was applied to authenticate species both in PCR-amplified and non-amplified heterogeneous biological samples. The results were determined visually and validated by absorption spectroscopy. The entire assay (hybridization plus visual detection) was performed in less than 10 min. The LOD (for genomic DNA) of the assay was 6 µg ml − 1 swine DNA in mixed meat samples. We believe the assay can be applied for species assignment in food analysis, mismatch detection in genetic screening and homology studies between closely related species

Investigation of the Emission Characteristics of Iso-Butanol Additives on Methanol-Gasoline Blends using Spark Ignition Engine / Hazim Sharudin ...[et al.]

Lower emissions of spark ignition engine can be achieved by using alcohol fuels such as methanol as it is more environmental advantage over fossil fuel. The methanol fuels can be further improved by added with iso-butanol as it have higher energy content and able to displace more gasoline fuel. Nevertheless, the research on the addition of lower ratio iso-butanol in methanol-gasoline blends specifically on exhaust emission is still not investigated thoroughly. Therefore, this study will focus on investigating the effect of iso-butanol additive on methanol-gasoline blends on the emission characteristics of spark ignition engine. The lower percentage (5%) of methanol-gasoline fuels was added with lower ratio of iso-butanol (5-15%) with 5% of volume increment. The experimental test were carried out on a 1.6-litre four-cylinder spark ignition engine at a fixed speed of 4000 rpm with increasing engine load form 10 Nm until 100 Nm. The results showed that the iso-butanol additive in methanol-gasoline blends was efficient to reduce the carbon monoxide (CO) and unburned hydrocarbon (HC) formation compared to base fuel. Among all tested fuels, M5B15 (Iso-butanol 15% + Methanol 5% + Gasoline 80%) blend gave lower CO and HC emissions by 12.45% and 16.18% at 100 Nm. Meanwhile, oxides of nitrogen (NOx) and carbon dioxide (CO2) emissions were higher for all methanol-gasoline blends with iso-butanol additives compared with that base gasoline. M5B15 blends gives higher emissions of NOx and CO2 by 11.45% and 11.74% at 100 Nm. This study summarized that iso-butanol additives can be applied in low percentage methanol-gasoline blends without any modification on the current existing engine, therefore reducing any serious environment impact

Outcomes after endovascular repair of arterial trauma

BackgroundEndovascular repair of peripheral arterial trauma using covered stent grafts is a minimally invasive alternative to open surgery in selected patients. Although the technical feasibility of endovascular repair has been established, there are a paucity of data regarding outcomes. The purpose of this study was to evaluate the short-term outcomes of endovascular repair in patients with peripheral arterial trauma.MethodsA review of a prospectively collected institutional trauma registry captured all patients with peripheral arterial injury who underwent endovascular repair from August 2004 to June 2012. Data collected included demographics, Injury Severity Score (ISS), mechanism, location and type of injury, imaging modality, intervention type, complications and reintervention, length of stay, and follow-up. Descriptive statistics were used for analysis.ResultsDuring the study period, we performed endovascular repair in 28 patients with peripheral arterial injuries. There were 20 male patients (71%) with a median age of 39 years (range, 13-88 years). The mean ISS was 17.2 (range, 9-41). The mechanism of injury was penetrating in 21 (75%) and blunt in seven (25%). The anatomic locations of the 28 arterial injuries were carotid (3 [11%]), subclavian (7 [25%]), axillary (6 [22%]), iliac (3 [11%]), and femoral/popliteal (9 [32%]). Findings consistent with injury on imaging included pseudoaneurysms (9 [32%]), extravasations (9 [32%]), occlusions (6 [22%]), and arteriovenous fistulas (4 [14%]). Technical success was achieved in all patients. The overall complication rate was 21%, with six patients requiring a secondary procedure. Two patients underwent a planned, elective conversion to open repair during the initial hospitalization. Four patients required conversion secondary to stent graft thrombosis. Three conversions were early (<30 days) and one was late (>30 days). The mean length of stay was 18.4 ± 22.9 days (range, 1-93 days), with a median follow-up of 13 months (range, 1-60 months). The overall limb salvage rate was 92% at 45 days and 79% at 93 days.ConclusionsThe present study outlines our early experience with endovascular repair of peripheral arterial injuries in a variety of anatomic locations. Overall complication rates are appreciable but can be effectively detected and managed with additional intervention. The inclusion of endovascular modalities in algorithms of trauma care holds considerable promise. The need to better define optimal algorithms for utilization and determine long-term outcomes of intervention requires significant additional study

Intentional left subclavian artery coverage during thoracic endovascular aortic repair for traumatic aortic injury

BackgroundThoracic endovascular aortic repair (TEVAR) is widely used for treatment of traumatic aortic injury (TAI). Stent graft coverage of the left subclavian artery (LSA) may be required in up to 40% of patients. We evaluated the long-term effects of intentional LSA coverage (LSAC) on symptoms and return to normal activity in TAI patients compared with a similarly treated group whose LSA was uncovered (LSAU).MethodsPatients were identified from a prospective institutional trauma registry between September 2005 and July 2012. TAI was confirmed using computed tomography angiography. The electronic medical records, angiograms, and computed tomography angiograms were reviewed in a retrospective fashion. In-person or telephone interviews were conducted using the SF-12v2 (Quality Metrics, Lincoln, RI) to assess quality of life. An additional questionnaire was used to assess specific LSA symptoms and the ability to return to normal activities. Data were analyzed by Spearman rank correlation and multiple linear and logistic regression analysis with appropriate transformations using SAS software (SAS Institute, Cary, NC).ResultsDuring the study period, 82 patients (57 men; mean age 40.5 ± 20 years, mean Injury Severity Score, 34 ± 10.0) underwent TEVAR for treatment of TAI. Among them, LSAC was used in 32 (39.5%) and LSAU in 50. A group of the LSAU patients (n = 22) served as matched controls in the analysis. We found no statistically significant difference in SF-12v2 physical health scores (ρ = −0.08; P = .62) between LSAC and LSAU patients. LSAC patients had slightly better mental health scores (ρ = 0.62; P = .037) than LSAU patients. LSAC patients did not have an increased likelihood of experiencing pain (ρ = −0.0056; P = .97), numbness (ρ = −0.12; P = .45), paresthesia (ρ = −0.11; P = .48), fatigue (ρ = −0.066; P = .69), or cramping (ρ = −0.12; P = .45). We found no difference between groups in the ability to return to activities. The mean follow-up time was 3.35 years. Six LSAC patients (19%) died during the follow-up period of unrelated causes.ConclusionsIntentional LSAC during TEVAR for TAI appears safe, without compromising mental or physical health outcomes. Furthermore, LSAC does not increase the long-term risk of upper extremity symptoms or impairment of normal activities