direct methods
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Author(s):  
Abdelrahman Mohamad ◽  
Fouzia Khadraoui ◽  
Nassim Sebaibi ◽  
Mohamed Boutouil ◽  
Daniel Chateigner

The necessity to build energy-efficient and low environmental impact buildings favors the development of biobased light-weight materials as hemp-foam concretes. In this context, experimental protocols were developed to study the effects of hemp shiv and the production methods on the water sensitivity of bio-based foamed concrete (BBFC). Foam concrete incorporates several materials and compounds: cement, protein-based foaming agent, ground granulated blast–furnace slag, metakaolin as a binder, and hemp shiv as bio-based aggregates. The study investigated first the effect of the incorporation of hemp shiv (from 0 to 15 vol%) and then the elaboration method, comparing direct method versus preformed method on the resulting physical properties, the isotherms sorption-desorption and the capillary water absorption of hemp-foam concretes. We observe an increasing porosity of the concrete with hemp shives content. Additionally, hemp shives increase the adsorption and the capillary absorption of water. Moreover, the preformed method produces concretes more sensitive to water than the direct methods since it increases its porosities.


Author(s):  
Da Eun Kim ◽  
Jin-hee Jeong ◽  
Yu Mi Kang ◽  
Young-Hoon Park ◽  
Yong-Jae Lee ◽  
...  

AbstractHow functional genetics research can be applied to improving crop yields is a timely challenge. One of the most direct methods is to produce larger inflorescences with higher productivity, which should be accompanied by a balance between stem cell proliferation and lateral organ initiation in meristems. Unbalanced proliferation of stem cells causes the fasciated inflorescences, which reflect the abnormal proliferation of meristems, derived from the Latin word ‘fascis’, meaning ‘bundle’. Maize, a model system for grain crops, has shown tremendous yield improvements through the mysterious transformation of the female inflorescence during domestication. In this review, we focus on maize inflorescence architecture and highlight the patterns of fasciation, including recent progress.


2022 ◽  
pp. 63-106
Author(s):  
Muhsin J. Jweeg ◽  
Muhannad Al-Waily ◽  
Kadhim Kamil Resan
Keyword(s):  

2021 ◽  
Vol 7 (12) ◽  
pp. 113281-113290
Author(s):  
Jorday Arostegui Morell ◽  
Eduardo Sierra Gil ◽  
Israel Gondres Torné ◽  
Fábio de Sousa Cardoso ◽  
Angilberto Muniz Ferreira Sobrinho

O trabalho apresenta uma comparação entre os resultados obtidos para a previsão da produção de eletricidade em instalações de energia solar fotovoltaica, usando diferentes métodos diretos. Devido à natureza intermitente e incerta da energia solar, associada à influência de múltiplos fatores meteorológicos, a geração de energia fotovoltaica necessita de ferramentas de previsão cada vez mais precisas para garantir o funcionamento eficiente e confiável do sistema. Nesse estudo, as previsões para cada hora analisada são calculadas por três dos métodos mais usuais e são comparadas usando o erro percentual absoluto médio como referência. Os resultados são testados com os dados de geração de energia obtidos do Parque Solar Fotovoltaico Imías, que tem uma capacidade instalada de 2,2 MWp. Independentemente dos métodos mostrarem que garantem uma previsão com alta precisão, existem diferenças na eficácia de cada previsão, nas mesmas condições.


2021 ◽  
Vol 2 ◽  
Author(s):  
Klara Mosshammer ◽  
Theresa Lüdke ◽  
Sarah Spitzner ◽  
Daniel Firzlaff ◽  
Kathrin Harre ◽  
...  

Hypotension in the middle ear can cause serious diseases and hearing disorders. Until now, pressure in the middle ear is measured indirectly by using the impedance of the tympanic membrane (tympanometry). Direct methods are just described in scientific studies and would be harmful in clinical routine. Here, we demonstrate a bio-compatible pressure sensor, which can resolve pressure changes in the range of −7.5 kPa up to +7.5 kPa, and due to its compact design (area of 2 × 4 mm2), can be directly implanted in the human middle ear. Furthermore, the read-out of the pressure sensor can be conveniently done using wireless data communication technologies employing a plate capacitor with an elastic dielectric for pressure monitoring and a planar coil. Thus, our sensor allows for direct pressure measurements in the middle ear, avoiding additional surgeries after device implantation.


2021 ◽  
pp. 322-329
Author(s):  
В.П. Клименко ◽  
Е.А. Лущай ◽  
А.С. Абдурашитова

Полиплоидные формы обращают на себя внимание своими положительными свойствами, одним из которых является увеличение по сравнению с диплоидными сортами размеров хозяйственно ценных органов. Значительное количество работ по полиплоидии растений в последнее время обусловлено развитием аналитических методов, таких как современные способы приготовления цитогенетических препаратов, цифровая микроскопия, проточная цитометрия, ПЦР-анализ. В настоящее время для получения полиплоидных форм растений используют системы культуры ткани. Успех индукции полиплоидии зависит от различных факторов: состава питательной среды, антимитотического агента, типа эксплантов, времени воздействия и концентрации веществ. В программах создания полиплоидных форм растений проводят исследования с использованием прямого подсчета хромосом, проточной цитометрии, ПЦР-анализа, а также косвенных методов изучения морфологических особенностей объектов. Методы изучения структуры эпидермиса листа являются простыми, быстрыми, неразрушающими и не требующими дорогих реагентов или оборудования. В качестве морфологических индикаторов плоидности обычно используют параметры устьиц (частота устьиц, размеры замыкающих клеток и количество хлоропластов в устьицах). Предлагаются простые протоколы прямого и косвенного методов анализа плоидности винограда. Наиболее успешными работами в области изучения плоидности растений можно считать исследования комплексные. Косвенные методы анализа следует использовать для массового скрининга исходной выборки, прямые методы - для точного изучения генома отобранных растений. Изучение морфологических особенностей эпидермиса листьев может быть использовано в селекционных программах создания виноградных полиплоидов. Исследование дает рациональное обоснование дальнейшей работы по анализу цитогенетических и морфологических особенностей полиплоидных растений винограда. Polyploid forms attract attention for their positive properties, one of which is an increase in the size of economically valuable organs compared to diploid varieties. A significant number of works on plant polyploidy in recent years is due to the development of analytical methods, such as modern methods for the preparation of microslides, digital microscopy, flow cytometry, PCR- analysis. Tissue culture systems are currently used to obtain polyploid forms of plants. The success of polyploidy induction depends on various factors, such as composition of the nutrient medium, antimitotic agent, type of explants, time of exposure, and concentration of substances. In programs for creating polyploid forms of plants, the research is carried out using direct chromosome counting, flow cytometry, PCR-analysis, as well as indirect methods for studying morphological characteristics of objects. Methods for study the structure of leaf epidermis are simple, fast, non-destructive and not requiring expensive reagents or equipment. Stomatal parameters (stomatal density, guard cell size, and the number of chloroplasts in stoma) are commonly used as morphological indicators of ploidy. Simple protocols of direct and indirect methods of ploidy analysis for grapes are proposed. Complex research can be considered as the most successful in the field of plant ploidy studies. Indirect methods of analysis should be used for mass screening of the initial sample, direct methods - for precise study of the genome of selected plants. The study of morphological characteristics of leaf epidermis can be used in breeding programs for the creation of grape polyploids. The research provides a rational basis for further work on the analysis of cytogenetic and morphological features of polyploid grape plants.


2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Konstantinos V. Spiliopoulos ◽  
Ioannis A. Kapogiannis

AbstractMechanical engineering structures and structural components are often subjected to cyclic thermomechanical loading which stresses their material beyond its elastic limits well inside the inelastic regime. Depending on the level of loading inelastic strains may lead either to failure, due to low cycle fatigue or ratcheting, or to safety, through elastic shakedown. Thus, it is important to estimate the asymptotic stress state of such structures. This state may be determined by cumbersome incremental time-stepping calculations. Direct methods, alternatively, have big computational advantages as they focus on the characteristics of these states and try to establish them, in a direct way, right from the beginning of the calculations. Among the very few such general-purpose direct methods, a powerful direct method which has been called RSDM has appeared in the literature. The method may directly predict any asymptotic state when the exact time history of the loading is known. The advantage of the method is due to the fact that it addresses the physics of the asymptotic cycle and exploits the cyclic nature of its expected residual stress distribution. Based on RSDM a method for the shakedown analysis of structures, called RSDM-S has also been developed. Despite most direct methods for shakedown, RSDM-S does not need an optimization algorithm for its implementation. Both RSDM and RSDM-S may be implemented in any Finite Element Code. A thorough review of both these methods, together with examples of implementation are presented herein.


Quaternary ◽  
2021 ◽  
Vol 4 (4) ◽  
pp. 42
Author(s):  
Robert G. Bednarik

The most extensive corpus of ancient immovable cultural heritage is that of global rock art. Estimating its age has traditionally been challenging, rendering it difficult to integrate archaeological evidence of early cultural traditions. The dating of Chinese rock art by ‘direct methods’ began in the late 1990s in Qinghai Province. Since then, China has acquired the largest body of direct dating information about the rock art of any country. The establishment of the International Centre for Rock Art Dating at Hebei Normal University has been the driving force in this development, with its researchers accounting for most of the results. This centre has set the highest standards in rock art age estimation. Its principal method, microerosion analysis, secured the largest number of determinations, but it has also applied other methods. Its work with uranium-thorium analysis of carbonate precipitates in caves is of particular significance because it tested this widely used method. The implications of this work are wide-ranging. Most direct-dating of rock art has now become available from Henan, but results have also been reported from Heilongjiang, Inner Mongolia, Ningxia, Jiangsu, Hubei, Guangxi, Yunnan, Qinghai, Tibet, and Xinjiang. Intensive work by several teams is continuing and is expected to result in a significantly better understanding of China’s early immovable cultural heritage.


2021 ◽  
Author(s):  
Yingying Xie ◽  
Peiliu Qu ◽  
Ling Liu ◽  
Xiao Du ◽  
Shilan Zhang ◽  
...  

Abstract Background Hypertension (HBP) often occurs together with hypertriglyceridemia that indicates elevated triglyceride (TG) and remnant cholesterol (RC) levels. Non-fasting (i.e. postprandial) blood lipid test after a daily meal has been recommended by the European Atherosclerosis Society (EAS). However, little is known about the difference between fasting and non-fasting cut-off values in assessing high TG (HTG) and high RC (HRC) in HBP outpatients. Methods Two hundred and twenty-five Chinese outpatients with HBP were enrolled in this study. According to the time of blood lipid test, they were divided into two groups, i.e. the fasting group (n=119) and the non-fasting group (n=139). Non-fasting levels of blood lipids at 2 h after a daily breakfast were also tested in 33 patients among the fasting group. Venous blood samples were collected. Serum levels of blood lipids were measured by the enzymatic and direct methods on a HITACHI 7170A analyzer or estimated via related formulas. Results The non-fasting group had significantly higher levels of TG and RC while lower levels of total cholesterol, low-density lipoprotein cholesterol and non-high-density lipoprotein cholesterol than the fasting group (P༜0.05). According to TG and RC cut-off values of the EAS, the percentages of HTG and HRC in the non-fasting group were 67.6% and 65.6%, respectively, while those in the fasting group were 57.1% and 52.9%, respectively. However, the percentages of HTG in the fasting state and at 2 h after a daily breakfast in 33 outpatients did not reach statistical significance (57.6% v.s. 51.5%). So did the fasting and at 2 h non-fasting percentages of HRC in them. Conclusion Non-fasting blood lipid test could find more HBP outpatients with HTG in Chinese outpatients with HBP. However, the percentage of HTG at 2h after a daily breakfast seemed to be close to that in the fasting state.


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