1,065 research outputs found
On the Symmetric Space Sigma-Model Kinematics
The solvable Lie algebra parametrization of the symmetric spaces is
discussed. Based on the solvable Lie algebra gauge two equivalent formulations
of the symmetric space sigma model are studied. Their correspondence is
established by inspecting the normalization conditions and deriving the field
transformation laws.Comment: 17 page
Integrated optimization of sustainable supply chains and transportation networks for multi technology bio-based production:A decision support system based on fuzzy Δ-constraint method
Developing and employing effective design methodologies can significantly improve the economic and environmental viability of renewable production processes. This study contributes by presenting a novel bi-level decision support system (DSS) to aid modelling and optimization of multi technology, multi product supply chains and co-modal transportation networks for biomass based (bio-based) production combining two multi-objective mathematical models. Considering the supply chain configuration optimized by the first level of the DSS, in the second level, the transportation network is designed specifying the most appropriate transportation mode and related transportation option under transfer station availability limitations. A hybrid solution methodology that integrates fuzzy set theory and Δ-constraint method is proposed. This methodology handles the system specific uncertainties addressing the economic and environmental sustainability aspects by capturing trade-offs between conflicting objectives in the same framework. To explore the viability of the proposed models and solution methodology, a regional supply chain and transportation network is designed using the entire West Midlands (WM) region of the UK as a testing ground. Additionally, scenario and sensitivity analyses are conducted to provide further insights into design and optimization of the biomass based supply chains
Network design and technology management for waste to energy production:An integrated optimization framework under the principles of circular economy
The design of waste to bioenergy supply chains (W-BESC) is critically important for meeting the circular economy (CE) goals, whilst also ensuring environmental sustainability in the planning and operation of energy systems. This study develops a novel optimization methodology to aid sustainable design and planning of W-BESC that comprise multiple technologies as well as multiple product and feedstock types. The methodology identifies the optimum supply chain configuration and plans the logistics operations in a given region to meet the energy demand of specified nodes. A scenario based fuzzy multi objective modelling approach is proposed and utilized to capture the economic and environmental sustainability aspects in the same framework. We test the proposed model using the entire West Midlands (WM) region from the United Kingdom (UK) as a case study. In this scope, a comprehensive regional supply chain is designed to meet the energy and biofertilizer demand of specific nodes considering available waste and crop type biomass in the region. Further analysis is conducted to reveal the impacts of main economic and technological parameters on the supply chain performance indicators
Spinal cord stimulation in failed back surgery
Objective: Spinal cord stimulation is used for
treating failed back surgery syndrome, chronic
arachnoiditis, peripheral neuropathies, postamputation
phantom pain, complex regional pain syndrome and
pain secondary to spinal cord injury. In this study we
present 7 cases with intractable neuropathic radicular
pain which developed following spine surgery.
Material and Methods: Spinal cord stimulation
was applied to 7 (3male/4 female) patients who had
failed back surgery syndrome and pain resistant to
medical and invasive methods, with the council
decision, which included neurosurgery, neurology,
and psychiatry. One week stimulation trial was
applied to all cases.
Results:The mean age of the patients was
54.85±7.64 years. The mean of pain intensity in
Visual Analog Scale was 8.71±0.74 at preoperative
status and post operative pain intensity was 2.27±0.67
at 6 months. Pain intensity significantly decreases
after spinal cord stimulation (p=0.000). One of the
three cases who had unsuccessful trial period received
morphine pump implantation, and percutaneous
lumbar sympathectomy was applied to another one.
One case who received permanent implantation was
replaced to another location due to skin erosion. There
was no morbidity.
Conclusion: Spinal cord stimulation is an effective
tool in reducing pain, in patients who have
unsuccessful lower back surgery with the correct
indications
Constraints on North Anatolian Fault Zone Width in the Crust and Upper Mantle From S Wave Teleseismic Tomography
We present high-resolution S wave teleseismic tomography images of the western segment of the North Anatolian Fault Zone (NAFZ) in Turkey using teleseismic data recorded during the deployment period of the Dense Array for Northern Anatolia array. The array comprised 66 stations with a nominal station spacing of 7 km, thus permitting a horizontal and vertical resolution of approximately 15 km. We use the current S wave results with previously published P wave teleseismic tomography to produce maps of relative VP/VSanomalies, which we use to highlight the difference in overall composition of the three terranes separated by the northern (NNAF) and southern branches of the NAFZ. Our results show a narrow S wave low-velocity anomaly beneath the northern branch of the NAFZ extending from the upper crust, where it has a width of âŒ10 km, to the lower crust, where it widens to âŒ30 km. This low-velocity zone most likely extends into the upper mantle, where we constrain its width to be †50 km and interpret it as indicative of localized shear beneath the NNAF; this structure is similar to what has been observed for the NAFZ west of 32°, and therefore, we propose that the structure of the NNAF is similar to that of the NAFZ in the east. The southern branch of the NAFZ does not show a very strong signature in our images, and we conclude that it is most likely rooted in the crust, possibly accommodating deformation related to rotation of the Armutlu/Almacik Blocks situated between the two NAFZ branches
Performance Analysis of Quantized Uplink Massive MIMO-OFDM With Oversampling Under Adjacent Channel Interference
Massive multiple-input multiple-output (MIMO) systems have attracted much attention lately due to the many advantages they provide over single-antenna systems. Owing to the many antennas, low-cost implementation and low power consumption per antenna are desired. To that end, massive MIMO structures with low-resolution analog-to-digital converters (ADC) have been investigated in many studies. However, the effect of a strong interferer in the adjacent band on quantized massive MIMO systems have not been examined yet. In this study, we analyze the performance of uplink massive MIMO with low-resolution ADCs under frequency selective fading with orthogonal frequency division multiplexing (OFDM) in the perfect and imperfect receiver channel state information cases. We derive analytical expressions for the bit error rate and ergodic capacity. We show that the interfering band can be suppressed by increasing the number of antennas or the oversampling rate when a zero-forcing receiver is employed
Interactions between Hazelnut (Corylus avellana L.) Protein and Phenolics and In Vitro Gastrointestinal Digestibility
In this study, we investigated the formation of proteinâphenolic complexes from dephenolized hazelnut meal protein isolates (dHPI) and hazelnut skin phenolic extracts (HSE) and their effects on the bioaccessibility of both hazelnut proteins and phenolics. The dHPIâHSE complexes were of considerable size and were dependent on HSE concentration due to aggregation. Although catechin was the main component of HSE, it did not cause aggregation, except for a slight rise in particle size. According to fluorescence quenching, the hazelnut proteinâphenolic extract complex had a linear SternâVolmer plot expressing static quenching between 0â0.5 mM concentration; the interaction was mainly dependent on hydrogen bonding and van der Waals forces (ÎH < 0 and ÎS < 0), and the reaction was spontaneous (ÎG < 0). According to Fourier transform infrared (FTIR) spectroscopy results, higher phenolic extract concentration caused an increase in irregular structures in hazelnut protein, while the lowest catechin and phenolic concentration altered the regular structure. Skin extracts did not alter the digestibility of dephenolized proteins, but dephenolization reduced the degree of hydrolysis by pancreatin. The formation of the proteinâphenolic complex had a beneficial effect on the bioaccessibility of hazelnut skin phenols, predominantly those on the galloylated form of the catechins, such as gallocatechin gallate and epigallocatechin gallate. Thus, the bioaccessibility and antioxidant activity analysis results showed that proteinâphenolic complexes obtained from hazelnut meal and skin may promote the transition of phenolic compounds from the gastrointestinal tract without degradation
Treatment Challenges in Pediatric Stroke Patients
Aim. In this study we presented our experience of 18 years on the etiology, risk factors, prophylactic and acute treatment, the effect of treatment to recurrence rate of patients with stroke. Methods. The population included 108 patients who had been treated for stroke at Pediatric Neurology Department of Ankara University with the diagnosis of arterial ischemic stroke and sinovenous thrombosis between January 1992 and
August 2010. Forty-one girls (38%) and 67 boys (62%) with mean symptom age 3.1 ± 4.04 years, (0â18 years old) were followed up with a mean period of 4.9 ± 3.78 years (0â17 years). Results. 30 patients had no risk factors, 34 patients had only one risk factor and 44 patients had multiple risk factors. Recurrence was seen in three patients. There was no any statistical correlation between the recurrence of stroke and the existence of risk factors (P = .961). Seventeen
patients received prophylactic treatment; 2 of them without any risk factors, 3 had one risk factor, 12 patients, who constituted the majority of our patients, had multiple risk factors (P = .024).
Conclusion. With this study we showed that the right prophylaxis for right patients reduces the rate of recurrence
How do learning orientation and strategy yield innovativeness and superior firm performance?
This paper attempts to shed light on the role of learning orientations of firms and their adoption of Porterâs generic strategies on four dependent variables: Behavioral innovativeness, product innovativeness, technological innovativeness and, ultimately, firm performance. Hierarchical regressions were run with data from a random sample of 121 firms operating in Turkey. Findings indicate that internally-focused learning, market-focused learning and differentiation strategy have significant effects on the three innovativeness dimensions. When firm performance is included as the eventual outcome variable into the analysis, internally-focused learning, focus strategy and product innovativeness emerge as its main predictors. In fast-paced, highly unpredictable market environments, managers can make use of these findings to their benefit in terms of elevating their firmsâ innovativeness and performance levels
The outcome of 41 Late-Diagnosed Turkish GA-1 Patients: A Candidate for the Turkish NBS
Background: Glutaric aciduria type 1(GA-1) is an inherited cerebral organic aciduria.
Untreated patients with GA-1 have a risk of acute encephalopathic crises during the first
6 years of life. In so far as GA-1 desperately does not exist in Turkish newborn screening
(NBS) program, most patients in our study were late-diagnosed. /
Method: This study included 41 patients diagnosed with acylcarnitine profile, urinary
organic acids, mutation analyses in the symptomatic period. We presented with
clinical, neuroradiological, and molecular data of our 41 patients. /
Results: The mean age at diagnosis was 14.8 13.9 (15 days to 72 months) and, high
blood glutaconic acid, glutarylcarnitine and urinary glutaric acid (GA) levels in 41
patients were revealed. Seventeen different mutations in the glutaryl-CoA dehydrogenase gene were identified, five of which were novel. The patients, most of whom were
late-diagnosed, had a poor neurological outcome. Treatment strategies made a little
improvement in dystonia and the frequency of encephalopathic attacks. /
Conclusion: All GA-1 patients in our study were severely affected since they were latediagnosed, while others show that GA-1 is a treatable metabolic disorder if it is
diagnosed with NBS. This study provides an essential perspective of the severe impact
on GA-1 patients unless it is diagnosed with NBS. We immediately advocate GA-1 to be
included in the Turkish NBS
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