scholarly journals The potential of full-electric aircraft for civil transportation: from the Breguet range equation to operational aspects

2021 ◽  
Author(s):  
Ingo Staack ◽  
Alejandro Sobron ◽  
Petter Krus
Keyword(s):  
Electric Propulsion ◽  
Air Transportation ◽  
High Expectations ◽  
Free Air ◽  
Electric Aircraft ◽  
Short And Long Term ◽  
Conceptual Study ◽  
Key Enabling Technologies ◽  
Range Equation

AbstractThe decades-old idea of electric-powered commercial flight has re-emerged alongside high expectations for greener CO2 emission-free air transportation. But to what extent can electric aircraft reduce the energy and environmental footprint of aviation? What should such aircraft look like, and how does their operation compare to conventional jet aircraft? What technologies are needed and which of them are already in place? This paper goes back to the basics of flight physics and critically analyzes some of the unresolved challenges that lay ahead. Current commercial operations are examined and the short-term effects of any electrification of short-range flights are quantified. Fundamental system components and basic design and operating concepts are analysed to highlight unavoidable constraints that often seem to be misunderstood or overlooked. These limitations are illustrated with a conceptual study of a full-electric FAR/CS-23 commuter aircraft and realistic estimations of its performance. It becomes clear that electric propulsion alone will not fully meet society’s expectations, even if key enabling technologies continue to develop as forecast. Nevertheless, this paper suggests that electrification may instead become one piece of a propulsion-technology mix that would more effectively address our short- and long-term emission goals.

scholarly journals Analysis and design of hybrid electric regional turboprop aircraft

2017 ◽  
Vol 9 (1) ◽  
pp. 15-25 ◽  
Author(s):  
Mark Voskuijl ◽  
Joris van Bogaert ◽  
Arvind G. Rao
Keyword(s):  
Electric Propulsion ◽  
Environmental Benefits ◽  
Analysis And Design ◽  
Electric Aircraft ◽  
Shaft Power ◽  
Hybrid Electric ◽  
And Performance ◽  
Battery Technology ◽  
Range Equation ◽  
Technology Level

Abstract The potential environmental benefits of hybrid electric regional turboprop aircraft in terms of fuel consumption are investigated. Lithium–air batteries are used as energy source in combination with conventional fuel. A validated design and analysis framework is extended with sizing and analysis modules for hybrid electric propulsion system components. In addition, a modified Bréguet range equation, suitable for hybrid electric aircraft, is introduced. The results quantify the limits in range and performance for this type of aircraft as a function of battery technology level. A typical design for 70 passengers with a design range of 1528 km, based on batteries with a specific energy of 1000 Wh/kg, providing 34% of the shaft power throughout the mission, yields a reduction in emissions by 28%.

CS06-04 - Short and long-term treatment outcomes in schizophrenia

2011 ◽  
Vol 26 (S2) ◽  
pp. 1789-1789
Author(s):  
H.-J. Moeller
Keyword(s):  
First Generation ◽  
Term Treatment ◽  
Receptor Imaging ◽  
High Expectations ◽  
Chronic Disorder ◽  
Second Generation Antipsychotics ◽  
Long Term Treatment ◽  
Schizophrenic Patients ◽  
Short And Long Term

Schizophrenia is a chronic disorder with a high risk of poor outcome in terms of symptoms and social functioning and possibly also progressive brain alterations. The relapse rate is high and each relapse can induce further aggravations, both in psychosocial as well as in neurobiological terms. Thus, acute and long-term treatment with the highest degree of effectiveness should be provided to the patients in acute and long-term treatment.Neuroleptic medication is the most important part of the treatment regimen for schizophrenic patients. The efficacy of neuroleptics in the acute and long-term treatment of schizophrenia is very well proven and the effect size is comparatively high. The second-generation antipsychotics (SGAs) have advantages over the neuroleptics of the first-generation (FGAs), and high expectations have therefore been put into them for the treatment of schizophrenia. Their better extrapyramidal-motor tolerability and efficacy in treating negative, depressive and cognitive symptoms, in addition to positive symptoms, supposedly result in a more favourable influencing of the overall course of the disease and in a higher quality of life for the patients, thus improving their acceptance by patients and leading to increased compliance. Differences in the pharmacological profile can be identified among others by receptor imaging approaches.

scholarly journals Short and Long term effects of Overeating (Atimatrashan) on health and well-being: A Conceptual Study

2021 ◽  
Vol 7 (2) ◽  
pp. 77-80
Author(s):  
Unnati A. Chavan ◽  
◽  
Narayan R. Sabu ◽  
Keyword(s):  
Well Being ◽  
Great Emphasis ◽  
Long Term Effects ◽  
Wide Range ◽  
Short And Long Term ◽  
Conceptual Study ◽  
Health And Well Being ◽  
Food Consumed ◽  
The Ideal

Overeating is the excess food consumed in relation to the energy that an organism expends. Out of various eating disorders overeating from supersize meal portions is termed as Atimatrashan in Ayurveda. In Ayurveda great emphasis has been given on the ideal quantity i.e., ‘matra’ of Aahara which is customized according to individual appetite. While occasional overeating predisposes to various disorders manifested through impaired digestive function, Habitual overeating eventually leads to obesity. Obesity being a state of chronic inflammation predisposes to wide range of diseases including Metabolic syndrome and Cancer. In this context, this paper discusses the Ayurvedic concept of Tridosha Prakop (vitiation of all the three Doshas) with the resulting ailments and Aamvish which is said to be formed as a result of habitual overeating and is thought to be Vishsadrushya (highly toxic) and param asaadhyam (incurable).

scholarly journals ANALISIS TRANSPORTASI UDARA, KUNJUNGAN WISATAWAN, NILAI TUKAR DAN KESEMPATAN KERJA DI INDONESIA: PENDEKATAN VECM

2020 ◽  
Vol 2 (1) ◽  
pp. 117
Author(s):  
Miya Pertiwi ◽  
Alpon Satrianto
Keyword(s):  
Exchange Rates ◽  
Forecast Error ◽  
Air Transportation ◽  
Fourth Quarter ◽  
Short Term ◽  
Causality Test ◽  
Employment Opportunities ◽  
Long Run ◽  
Short And Long Term

This study aims to identify and analyze responses between air transportation, tourist visits, exchange rates and employment opportunities in Indonesia. This type of research is descriptive and associative, where the data used are secondary data in the form of time series from 2000 fourth quarter to 2018 fourth quarter. This study uses the Vector Error Correction Model (VECM) method through the analysis of block causality test, Impulse Response Function (IRF) and Forecast Error Variance Decomposition (FEVD) to seeing the variability response of an endogenous variable due to the presence of other endogenous variables. The results of this study indicate that: (1) Variability of air transportation is not contributed by the shock of tourist visits, exchange rates and employment opportunities in the short term, but in the long run, variability of air transportation is contributed by shock of tourist visits, exchange rates and employment opportunities. (2) Variability of tourist visits is only influenced by short-term air transportation shock. Whereas air transportation, exchange rates and employment opportunities in the long run contribute to influencing the variability of tourist visits in Indonesia. (3) Exchange rate variability is contributed by air transportation shock, tourist visits and work opportunities in the short and long term. (4) Variability of employment opportunities is contributed by air transportation shock, tourist visits and exchange rates in the short and long term in Indonesia.

scholarly journals An Empirical Analysis on the Elasticity of Air Transportation Demand: Sample of Turkey

2017 ◽  
Author(s):  
Harun Bal ◽  
Pınar Gümüş Akar ◽  
Müge Manga
Keyword(s):  
Air Transportation ◽  
Transportation Demand ◽  
Development Indicators ◽  
Income Elasticities ◽  
Positive Effects ◽  
Passenger Demand ◽  
Price And Income Elasticities ◽  
Development Goals ◽  
Short And Long Term

Air Transportation, which is a sector ever-increasing its volume and importance because of requiring infrastructural investments, providing fast and reliable transportation facilities, offering employment and its the positive effects on the other sector activities. The demand, for air transportation which is appeared in development goals of many countries and the development indicators of the World bank, is constituted one of the most important components. The aim of this study is estimated of the sensitivity to income and price, air transportation demand in Turkey. In this direction, it is estimated the price and income elasticities in the short and long term by the FMOLS and VEC method for the air passenger demand using the data of GSYH, flight ticket price index and the number of passengers in Turkey in the period of 2007Q1-2016Q1. The results obtained, consistent with expectations, are indicated that the price inelasticity of the air passenger demand in Turkey is high and according to the income elesticity parameter is luxury good.

scholarly journals Air Transportation, Economy and Causality: Remote Towns in Brazil’s Amazon Region

2021 ◽  
Vol 13 (2) ◽  
pp. 627
Author(s):  
Vicente Aprigliano Fernandes ◽  
Ricardo R. Pacheco ◽  
Elton Fernandes ◽  
Manoela Cabo ◽  
Rodrigo V. Ventura ◽  
...  
Keyword(s):  
Economic Growth ◽  
Gross Domestic Product ◽  
Empirical Studies ◽  
Air Transportation ◽  
Amazon Region ◽  
Air Transport ◽  
Domestic Product ◽  
Passenger Transport ◽  
Short And Long Term

There is a vast amount of literature on relations between air transport activities and economic growth. The recognition that these are important relationships has aroused the interest of researchers, who have studied them with regard to remote towns. The empirical studies have concentrated more on developed areas, such as Europe, North America, and Australia. No empirical studies were found for Brazil, which holds most of the Amazon region. In this study, the Granger causality method was used to investigate for causal relationships between regular domestic air passenger transport links and the gross domestic product of small municipalities in this region. The results indicate short- and long-term, two-way causality in which gross domestic product has a stronger impact on air transport than vice versa.

Short- and Long-Term Results of Total vs Subtotal Thyroid- ectomies in the Surgical Treatment of Graves' Disease

Swiss Surgery ◽  
2001 ◽  
Vol 7 (1) ◽  
pp. 20-24 ◽  
Author(s):  
Robert ◽  
Mariéthoz ◽  
Pache ◽  
Bertin ◽  
Caulfield ◽  
...  
Keyword(s):  
Recurrent Laryngeal Nerve ◽  
Nerve Palsy ◽  
Recurrent Laryngeal Nerve Palsy ◽  
Laryngeal Nerve ◽  
Long Term Results ◽  
Graves Disease ◽  
Laryngeal Nerve Palsy ◽  
Short And Long Term

Objective: Approximately one out of five patients with Graves' disease (GD) undergoes a thyroidectomy after a mean period of 18 months of medical treatment. This retrospective and non-randomized study from a teaching hospital compares short- and long-term results of total (TT) and subtotal thyroidectomies (ST) for this disease. Methods: From 1987 to 1997, 94 patients were operated for GD. Thirty-three patients underwent a TT (mostly since 1993) and 61 a ST (keeping 4 to 8 grams of thyroid tissue - mean 6 g). All patients had received propylthiouracil and/or neo-mercazole and were in a euthyroid state at the time of surgery; they also took potassium iodide (lugol) for ten days before surgery. Results: There were no deaths. Transient hypocalcemia (< 3 months) occurred in 32 patients (15 TT and 17 ST) and persistent hypocalcemia in 8 having had TT. Two patients developed transient recurrent laryngeal nerve palsy after ST (< 3 months). After a median follow-up period of seven years (1-15) with five patients lost to follow-up, 41 patients having had a ST are in a hypothyroid state (73%), thirteen are euthyroid (23%), and two suffered recurrent hyperthyroidism, requiring completion of thyroidectomy. All 33 patients having had TT - with follow-ups averaging two years (0.5-8) - are receiving thyroxin substitution. Conclusions: There were no instances of persistent recurrent laryngeal nerve palsy in either group, but persistent hypoparathyroidism occurred more frequently after TT. Long after ST, hypothyroidism developed in nearly three of four cases, whereas euthyroidy was maintained in only one-fourth; recurrent hyperthyroidy was rare.

Short- and long-term memory tasks predict working memory performance, and vice versa.

2019 ◽  
Vol 73 (2) ◽  
pp. 79-93 ◽  
Author(s):  
Ian Neath ◽  
Jean Saint-Aubin ◽  
Tamra J. Bireta ◽  
Andrew J. Gabel ◽  
Chelsea G. Hudson ◽  
...  
Keyword(s):  
Working Memory ◽  
Memory Performance ◽  
Long Term Memory ◽  
Term Memory ◽  
Short And Long Term
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